What is a combi oven? Course work: Combi steamer and its application in the food industry What is a combi steamer in a catering unit? Reasonability of purchase

This is the process of cooking food under the influence of hot air currents. Thanks to this, the food turns out evenly processed, with a beautiful crust.

What is a combi oven in a catering unit? Reasonability of purchase

Despite its relatively small size (compared to an industrial oven), the combi oven is capable of performing the functions of such equipment as:

• convection oven;
• deep fryer;
• double boiler;
• oven;
• oven;
• proofing cabinet.

Thanks to the exquisite settings of the combi oven, chefs can prepare dishes of any complexity. Its presence in a professional kitchen can save space, precious time, which is always in short supply, the owner’s nerves and money.

The number of loaded trays in this equipment varies from 3 to 20, the most popular size is equivalent to a gastronorm container size 1/1 (530*325mm). We will tell you here how to choose a combi oven based on your needs, looking at the tasks they should perform point by point.

Connection type. Gas or electricity?

Like any equipment, a combi steamer (depending on the model) can be connected to both gas and electricity. Let's look at the pros and cons:

• What is a gas combi oven? This is equipment that can be connected to liquefied or natural gas rather than electricity. Such equipment is more expensive than a conventional 380 V unit, but the difference in price pays off very quickly, since gas is cheaper than electricity.

• The main disadvantage is that it cannot always be used. By sanitary standards you will not be allowed to use your kitchen gas equipment, if the premises are located in a residential building.

Today (we found out what it is and where it is used) only European brands can provide it to their customers. Russian manufacturers do not yet have the ability to provide the market with stably operating gas combi steamers. This is due to the fact that the final equipment must comply with CE standards and have gas safety certificates. If all production conditions are met, then the final price of Russian equipment will be no less than that of European equipment. In such conditions, it is very difficult to withstand competition, since the main trump card of Russian combi ovens is the price and the full package of necessary documentation.

Classic or "marine" version

Almost every type of industrial equipment has a “marine” variation. No, this does not mean that it is decorated with anchors and shells. Marine equipment is stronger, more reliable, able to withstand long periods of time on board a ship on the high seas or on coastlines without losing its performance characteristics.

What does a marine combi oven mean in the context of work:

• functioning in conditions of contrasting external temperatures;
• operation in conditions of high humidity;
• additional strength of the metal, preventing corrosion;
• ignoring vibration;
• strong attachment to the floor.

For all this, you will have to pay an additional 20% of the cost of a classic combi steamer at a time and get equipment that will not let you down even in the most difficult conditions.

Equipment from Russia. Abat

And here they are - the darlings of government contracts. Abat combi steamers perform well under medium load conditions. They are good where simple food is prepared without any claims to special complexity. In their line they have models with 2 types of steam generation:

• Injection combi steamers. For 6 (145,000 rubles) and 10 (167,000 rubles) levels of size 1/1. The injection type of steam generation is characterized by the fact that it is achieved by injecting water into an already heated working chamber. This makes it difficult to perform such a function as “steam + low temperature,” otherwise called a “proofer,” but it is inexpensive and reliable.

• Boiler combi steamers. For 6 (175,000 rubles) and 10 (197,000 rubles) levels of size 1/1. The boiler type of operation is characterized by the fact that steam is generated separately and in this form passes into the working chamber. The range of functions is becoming wider, the price is higher.

The equipment is good for everyone, except for the ability to work for wear and tear - it is not recommended to load all the provided levels at the same time.

Soulful and high quality. Italian equipment Unox

The next stage in the evolution of combi ovens is equipment from the Italian brand Unox. Yes, it's more expensive, but the quality is worth it. This is visible in everything - the build quality, the quality of the metal and the range of functions. There are models:

• Each electric model has a "gas twin brother". The price of the latter is approximately 20% higher. Gas combi oven - what is it? The information is given above, be guided by the needs and operating conditions.
• For 3 (140,000 rubles), 5 (165,000 rubles), 7 (190,000 rubles), 10 (250,000 rubles), 20 (400,000 rubles) baking trays size 1/1. To each according to his needs.
• With mechanical and electronic control types. The first is good because it is 20 thousand cheaper than the second, with all other characteristics being equal, and it is also more difficult to break. The second is appropriate where complex settings and delicate, delicate dishes are involved.

Combi oven - what is it according to the Germans. Rational

Combi steamers of this brand can be placed in the chamber of weights and measures. Ideal, standard.

Well, very, very expensive. Their acquisition is justified when it comes to haute cuisine and scale. The types are as follows:

• With mechanical control CombiMaster for 6 levels 1/1. Version for 380 V (550,000 rubles) and gas (690,000 rubles).
• With mechanical control CombiMaster for 10 levels 1/1. Version for 380 V (790,000 rubles) and gas (890,000 rubles).
• With mechanical control CombiMaster for 20 levels 1/1. Execution only for 380 V (1,600,000 rubles).
• WITH electronically controlled Rational SCC 5 Senses for 6 levels 1/1. Version for 380 V (780,000 rubles) and gas (930,000 rubles).
• With electronic control Rational SCC 5 Senses for 10 levels 1/1. Version for 380 V (1,100,000 rubles) and gas (1,200,000 rubles).
• With electronic control Rational SCC 5 Senses for 20 levels 1/1. Execution only for 380 V (1,850,000 rubles).

The list of their capabilities is endless, so we can only say one thing: Rational is one of the few brands that can clearly make it clear what a combi oven is. What is it capable of preparing that sets it apart from other representatives of thermal equipment.

Combi steamer in government kitchens

We will now talk about kindergartens, schools, hospitals and nursing homes. They are united by the fact that food products at all stages of preparation must undergo strict control, not a step aside from verified technological maps. The food is specific - limiting fat, steaming or simmering, baking. Everything is according to the canons of a healthy, gentle regimen. A combi oven can provide all this without much effort.

It is capable of performing 80% of all thermal operations required during the cooking process. A unique combination of heating elements and fans allows you to cook different dishes at the same time - from cutlets to cottage cheese casserole, without worrying that smells may mix. Due to the adjusted cooking mode, which the chefs set before loading the trays, the process takes less time, which not only preserves most of the vitamins, but also saves the time of the working staff. A combi oven (what it is and where it is used, we indicated above) is now installed in almost every catering unit at a government institution, as it satisfies all requests for sanitary standards and technological maps.

Based on the “needs/price” ratio, it is most appropriate to install equipment from the Russian brand Abat, which was described above, in such facilities. It is easy to use, has the necessary documentation package and is relatively inexpensive, which is important for government-supported organizations.

Bottom line

Whether you need a combi oven in your kitchen or not is entirely up to you to decide. It may seem that the list of its practical capabilities is scant (yes, it happens), that it is easier to install a barbecue and an oven, but over time you will return to it as an object of exceptional utility.

So, combi oven - what is it? The photos are shown above, and we have told and explained everything else more than once in this article, but you can finally verify that we are right only by seeing it in action. Attend several master classes that are regularly held by industrial equipment dealers, and you will see that a combi steamer can save and earn money at the same time.

Course design assignment

Introduction

3. Descriptions of the device (technological diagram of the installation)

4.1 Technological calculation

4.2 Thermal calculation

Application

Conclusion

Bibliography

Introduction

What is a combi oven?

It is generally accepted that the history of combi ovens began at an exhibition in Frankfurt am Main in 1976, when a young German company presented its first model of the device to the public. Since then, the RATIONAL company and the rational combi steamer have been truly strongly associated with traditional German quality and are recognized all over the world. However, in fairness, we note that the Rational company, founded 3 years before this significant exhibition (in 1973), was already significantly ahead in its development of another, more famous German company - Kueppersbusch.

The very idea of ​​a steam convection oven was already being studied by Kueppersbusch specialists in the year the Rational company was founded (1973). Their technical solution– the Kueppersbusch combi steamer was also introduced in 1976. It is probably not worth comparing the technical potential and capabilities of the young company Rational and one of the clear market leaders - the Kueppersbusch company. It would be more correct to take off my hat to the marketers of the Rational company. Their efforts were correctly directed and bore fruit - the market newcomer managed to declare its primacy, which brought dividends and gave the necessary impetus to further development. Business is largely about advertising and the correct presentation of information.

However, remaining true to its age-old traditions, Kueppersbusch consistently develops its combi steamer solutions that correspond to the main motto of the company - ideal as principle. However, what is a combi oven or steam convection oven and why was this technical solution considered almost a revolution in the world of gastronomy?

The combi oven combines the capabilities of a convection oven and a steamer, significantly optimizing work in the kitchen. Compared to its predecessors, the combi steamer had greater power, capacity and, at the same time, had smaller dimensions. A lot has changed since then. Combi steamers have become more complex in their internal structure, easier to handle and operate.

The main difference between a combi oven and a combi oven is that the first one has an operating mode switch. In the simplest combi steam ovens (steam convection ovens), three operating modes are required: “steam”, “convection”, “steam convection”.

More advanced models of combi ovens have additional, specific cooking modes. The advantages of ovens include shorter cooking times (by approximately 20%) compared to traditional equipment, as well as adjustable power levels to save energy.

Combi steamers allow you to perform up to 70% of the total number of all possible heat treatment operations, and thereby replace 40% of thermal equipment. The circulation of hot air and steam separately or in combination allows you to use various methods of cooking products in one combi oven; frying, baking, steaming, stewing, poaching, baking and regeneration. The main operating modes of a combi oven are convection, steam cooking, as well as a combined cooking option when steam and hot air are used simultaneously.

The use of a combi oven allows you to implement most technological operations in one high-performance apparatus, without sacrificing quality, simultaneously process various products. As a rule, installing a combi oven in a hot shop saves production space, creates favorable working conditions for personnel and reduces the cost of physical labor.

To prepare fried rabbit in a combi oven, the “Steam Convection” operating mode is mainly used. Preparing this dish in a combi oven is very simple, you just need to set a certain task (program), and the smart machine will do everything itself: The temperature of the working chamber can be adjusted in the range from 30°C to 300°C. At the same time, the optimal humidity is always set in the working chamber, preventing the product from drying out, heat treatment takes place using hot air, uniformly supplied by the chamber fan, and a powerful current of hot air is generated, guaranteeing a uniform temperature at all its points. Hot air or heat envelops the product, binds meat protein and prevents the release of meat juice, ensuring the juiciness of the meat even at the highest temperatures.

And when preparing the same product without the services of a combi oven, they mainly use a frying pan for frying, an oven or broiler for simmering or directly for frying without preliminary cooking, a special pasuda for stewing (cauldron, “duckling”), a grill is used extremely rarely, since the meat turns out dry and tough. Like this.

In general, rabbit meat is considered a dietary product. It is mainly preferred by those who monitor their health and figure. This product is often prescribed to people suffering from diabetes.

Rabbits are also animals of agricultural importance; They are grown both on an industrial scale (farms, collective farms, etc.) and individually, just at home.

1. Classification and characteristics of the main processes of food technology

1.1 Technophysical methods for processing food raw materials and food products

One of the main technological processes of production food products, in which raw materials, undergoing a complex of complex physical-chemical, structural and other changes, are transformed into a finished product, is heat treatment. The quality and technical and economic indicators of the finished product largely depend on the method and mode.

The purpose and purposes of heat treatment are varied:

When producing ready-to-eat products, products (raw materials) are brought to a state of culinary readiness, most vegetative forms of microorganisms are destroyed and enzymes are inactivated to the required extent, while, for example, in products of animal origin, denaturation and coagulation of muscle proteins and disaggregation of connective tissue proteins occur;

Heat treatment can be preliminary, in which the product (raw material) is subjected to short-term heating to prepare it for subsequent processing;

When defrosting, melting - heating in order to change the structural state, and so on.

The depth of changes that occur in food products during heat treatment depends mainly on the temperature reached inside the product, the duration and method of heating, the presence of water in the product itself or in the heating medium, the contact of the heating medium with the mass of the product, the magnitude of the partial pressure of water vapor in the heating medium. environment, the use of radiant energy, and so on.

1.2 Changes in the properties of products during heat treatment

Heat treatment of products is carried out different ways: immersion in a liquid medium; exposure to steam-air and steam-water mixtures of live steam, electrical contact heating, microwave energy, infrared radiation and others, as well as a combination of the above methods. Depending on the goal, you can obtain a final product with the required properties by using one or another heat treatment method.

According to the technological purpose, all methods of thermal processing of food products can be divided into main and auxiliary, and according to the presence of moisture in the heating medium, its effect on the product and the method of supplying energy - into wet, dry and combined.

The main methods of heat treatment are those in which appropriate changes occur in the physical, chemical, structural and other properties and states of the product, as a result of which it becomes suitable for food (for example, in the production of sausages and culinary products and canned food, baking bread and others) or the properties of the raw material change significantly and it passes from one quality state to another (for example, fat rendering, gelatin extraction, and so on).

Auxiliary methods of heat treatment include those in which the raw material being processed does not undergo significant changes: scalding, singeing, frying, drying, and so on.

They, as a rule, precede the main methods of processing products, and in some cases contribute to giving the raw materials specific properties (frying, sautéing, blanching, etc.) necessary for the production of the corresponding product.

Heat treatment of meat and meat products

Heat treatment of meat and meat products is carried out in order to bring the product to a state of culinary readiness; destroying vegetative forms of microorganisms and increasing the stability of products during storage; fixing the structure of the meat product; imparting the required organoleptic properties finished product (appearance; color, taste, smell, consistency).

Heat treatment of meat and meat products causes structural, physico-chemical and other changes, the depth of which depends on temperature. Thus, heating muscle tissue for 45 minutes at 50°C causes a small secretion of meat juice, which has a cloudy and viscous appearance, while the pink color of the meat remains. There is no noticeable reduction in muscle volume; it continues to remain soft, but some thickening is already noticeable.

After heating for 45 minutes at 60°C, the pink color of the meat completely disappears, and the muscle volume decreases. The amount of juice separated is small; the coagulated particles in it noticeably increase. Muscle tissue becomes denser.

PHYSICAL PROPERTIES OF MEAT

The density of the various tissues that make up the meat is the same. The average density of adipose tissue is 0.9 s-0.97 (l of tissue fat with an insignificant fat content); The average density of low-fat meat is about 1. (The specific heat capacity of meat also primarily depends on the quantitative ratio of tissues in the composition of this meat, since each tissue has its own specific heat capacity: muscle - 3.48 kJ/(kg-deg); fat (contains 20-30% water) 2.97 kJ/(kg deg); dense bone-1.25 kJ/(kg-g<лс костная пористая - 2,97 кдж/(кг град).

Basically, the specific heat capacity of meat and meat products depends on the moisture content in the components of the product, as well as on the amount of dry matter and fat and the heat capacity at a given temperature.

The thermal conductivity of meat depends on its composition, as well as the direction of heat flow relative to the length of the axis of the muscle fibers; The thermal conductivity of muscle tissue in the direction parallel to the fibers is somewhat less and is about 0.88 of the thermal conductivity perpendicular to the fibers.

The thermal conductivity coefficient of meat is difficult to determine, since it depends on the chemical composition and condition of the meat, depending on the nature of the technolytic processing. The thermal conductivity coefficient of muscle tissue averaged 1.8 kJ/(m 2 -h-deg), fat - about 5.8 kJ/(m 2 h-deg) of lean meat - about 2.0 kJ/(m 2 h-deg). hail).

The average volumetric expansion of meat during freezing due to the conversion of water into ice is 8-10%, depending on the amount of moisture in the meat and meat product and the temperature of the frozen meat, i.e., depending on the amount of water converted into ice.

2. Classification and characteristics of thermal equipment

A combi oven is currently the most popular, automated, multifunctional device that is used in catering establishments for frying, stewing, baking, poaching, defrosting and heating chilled products, and steaming various products. Combi steamers are simple and easy to use, allowing you to achieve high productivity with relatively small dimensions.

The main effect of a combi oven during cooking is achieved through intensive ventilation of heating air and the use of an adjustable humidification system. Forced convection allows you to equalize the temperature field in the working chamber and create the same heating conditions in any of its zones, loading the chamber with the product to the maximum.

Combi steamers are equipped with a humidification system with portioned steam supply based on a signal from a humidity sensor, which ensures guaranteed maintenance of a given humidity level. Steam in these devices is supplied to the heating medium in a strictly dosed form based on a signal from a humidity sensor (these devices are usually equipped with electronic or digital control systems).

Combi ovens (convection ovens) have long occupied a strong place in the professional kitchen. In canteens, bars, cafes, restaurants, fast food restaurants, catering and, especially, in the developing field of organizing buffets, the advantages and capabilities of this technology have become indispensable. The concept of organizing a modern professional kitchen involves increasing versatility, reliability and the use of the latest technology. Regardless of whether we are talking about organizing a small eatery or a reputable restaurant, customer requests and requirements for a professional kitchen are increasing.

The desire to expand the range of offer as much as possible while always maintaining high quality food is complicated by the presence of differently trained staff with different national traditions. This situation requires not only consistently high efficiency of the equipment, but also extreme ease of maintenance. These are precisely the qualities that Kueppersbusch offers in its new version of the Convect-Air series of paracoconvection ovens.

Combi steamers

LEARN memory function: it allows you to easily write an already tested recipe into the oven memory, bypassing programming.

Library CONVECT - AIR. There has never been such a volume of a library before - 170 recipes for dishes worked out in practice were stored in the oven.

Additional reduction of air flow: optimal for preparing sensitive foods, such as delicate pastry dough. Just press a button and the fan speed is reduced significantly.

COOL PERFECT: automatic cooling of the chamber from 200 0C to 100 0C in just 30 seconds. Still unsurpassed speed, which allows you to change the cooking mode in the shortest possible time. The cooling process occurs with the door closed, thanks to the particularly robust design of the chamber.

DUO PERFECT: intelligent system for measuring the temperature inside the product using two multi-sensor probes with numerous measuring points installed in them. Ideal for simultaneous cooking of products with different weights and weights. You will look in vain for this achievement from other manufacturers.

With the CLIMA PERFECT and CLIMA COMFORT functions you can automatically set optimal oven conditions. High quality of dishes is guaranteed, weight losses during cooking are reduced. Hidden from view, built-in TURBO DRIVE camera cleaning system. It is enough to lower the drain probe into a container with washing liquid and the chamber will begin to clean without your help.

Triple glazing of the door: it is responsible for saving energy and maintaining an appropriate climate in the chamber. Impact resistance, uniform heat distribution in the chamber.

Comfort series combi ovens

Comfort - Just like the professional CPE series, the CCE series is equipped with a hygienic CleanPanel panel and the ColorlLogiControl system and meets the increased requirements for a professional kitchen. The ClimaComfort system automatically monitors the optimal climate in the chamber. The oven is also equipped with an LED display, the LEARN function, designed to remember cooking recipes, and other functions important for the user.

Operating modes: convection mode, steam mode, combined mode, low-temperature steam mode, low-temperature convection mode, low-temperature combined mode.

Special operating modes: regeneration, forced steam mode 120 C, Roast + Hold, Delta – T.

Additional functions: individual steam injection, 4-fold reduction in fan speed, condenser valve for manual removal of humidity, ClimaPerfect - automatic. measurement and adjustment humidity, SAFE function - blocking of entered parameters, CoolPerfect - rapid cooling of the chamber, pre-heating function, energy-saving operating mode, TurboDrive - chamber cleaning system (additional equipment).

Controls: ColorLogicControl - interactive control, CleanPanel - touch control panel, clear text monitor, full text LED display, LED display (temperature, time, core temperature), core temperature readings, remaining time readings, suggested parameters for recipes according to choice, menu of favorite programs used, reminder function with acoustic signal, 6 languages ​​​​of communication on an alternative basis.

Memory: LEARN function for recording recipes, 100 places for recording with 10 steps, entering a program into any program place, entering a program in full text.

Equipment: electric power, steam generator for devices with power supply, longitudinal arrangement of GN-tank in the chamber, temperature mode 30-300 C, electronic control, reduced heating and gentle operation of the fan and heating in low-temperature mode, DuoPerfect temperature probe, date and time, preliminary setting the start-up time, automatic fan reverse, automatic condensate cooling, automatic emptying of the steam generator, 4 levels of water saving for the steam generator, protection against dry running of the steam generator, descaling / scale diagnostic system, pre-start self-test program with error code display, data storage when power failure, hygienic door with triple glazing, two-step door opening, door installation on the left for tabletop version (optional equipment), bath for collecting and automatically draining condensation, hygienic bath for collecting condensation in the door, door seal, hygienic chamber design, halogen lighting with glass-ceramic protection, built-in condensate drain pipe, protective fan grille.

Accessories: roll-up rack for tabletop appliances, roll-up trolley for floor-standing appliances, shower, installation and operating instructions for appliances

Additional equipment: trolley for receiving the closing rack, rack for recuperating plates – present. cutlery, plate regeneration trolley - floor-standing cutlery, thermal hoods for table-top and floor-standing cutlery, stands for tabletop cutlery, container for spraying cleaning agent, cleaning agent, descaling agent, instructions for installing and operating the cutlery.

The Abat combi oven is designed for cooking food in various modes. Internal and facing surfaces are made of high quality stainless steel. The device has an electronic control panel, oven lighting, 6 levels for GN 1/1 baking sheets, a timer up to 10 hours, a temperature probe and height-adjustable legs.

Today, two modifications of combi steamers are produced:

1. Boiler rooms (PKA 6-1/1P and PKA 10-1/1P)

2. Injection (PKA 6-1/1V and PKA 10-1/1V)

The boiler system is the most common steam generation system. The boiler is a flask in which the heating element is located. The water is heated in a steam generator located in the inside of the combi oven. With sufficiently rapid boiling and evaporation, steam enters the working chamber through a special valve. Some chefs consider the boiler system to be an outdated solution, energy-intensive and bulky. On the other hand, the boiler system is considered to be more accurate. Calculating how much steam needs to be added to the chamber is much easier than calculating how much water to add so that it turns into the required volume of steam. When working on boiler machines, as a rule, only one problem arises, which, however, is quite simple to solve. It is necessary to connect the combi steamer to the water main through a special water softener, which will increase the service life of the boiler. To fully protect boiler heating elements from scale formation, most manufacturers of combi steamers offer special liquids for cleaning boiler systems from scale. Cleaning liquid is poured through a special hole in the upper part of the combi oven, after which the device is started in cleaning mode, and after a few minutes the boiler is cleaned. Boiler machines are quite expensive, which is why global manufacturers have developed injection combi steamers that have not lost their basic functions and at the same time become cheaper.

Steam is generated directly in the working chamber. In combi ovens with an injection steam generation system, water is supplied through a small tube to the center of a rotating turbine. A high-speed turbine disperses water into tiny particles with a vortex flow, which evaporate on circular heating elements and fill the working chamber with steam. In terms of its performance characteristics, the injection system is practically no different from the boiler system. When operating in combined mode, just like in boiler combi steamers, you can regulate the steam supply. Along with boiler combi steamers, injection models are actively occupying their position in the professional kitchen.

Combi steamer RATIONAL

RATIONAL combi steamers have a simple and understandable control system structure. To enter information, simply use the two buttons for wet and dry heat - each separately, sequentially or together - and use the adjustment dial. Everything else happens automatically. Product weight loss during heat treatment is reduced by up to 60%, and during cooking you save up to 25% of its weight. Dishes prepared in RATIONAL combi ovens retain vitamins, minerals and nutrients.

Three model ranges of combi ovens - CD, CM and CPC - allow you to optimize the production process and achieve excellent quality of finished products. Models of the CM series have a thermocore and 9 preset programs. The most advanced CPC series is equipped with an intelligent assistant chef - the IQT system, which includes 12 ready-made programs and the ability to independently create 99 programs of up to 9 steps each.

Combi steamers are designed for heat treatment of meat and fish products, vegetables, potatoes, cereals, proofing and baking of bakery and confectionery products, preparation of desserts and allow:

In the “steam” mode - boil, heat, blanch, pasteurize, stew, simmer, soak, prepare for vacuum packaging;

In the “hot air” mode - cook at low temperatures (up to 100 ° C), fry to form a crust, bake;

In the “combination of hot air and steam” mode - fry with steam, reheat, bake with steam, boil.

In addition, combi steamers of the CPC series allow operation in the “forced extinguishing” and “gentle extinguishing” modes. The “regeneration” mode is necessary for heating previously prepared dishes without the formation of crusts and puddles of juice and is indispensable for banquet service, and in the “low temperature cooking” mode they prepare tender and juicy meat with a weight loss of no more than 12%.

Original RATIONAL accessories expand the possibilities of using your combi steamer. They are designed to work in harsh operating conditions, are manufactured with the highest quality, are durable and practical.

The RATIONAL combi steamer uses additional equipment such as:

1. Cassettes and carts.

Cassettes mounted on trolleys allow you to quickly load and unload entire batches of cooked food in large combi ovens. There are cassettes for gastronorm containers and plates. One of the ready-made programs of CPC devices allows you to automatically reheat previously prepared dishes portioned into plates. When serving banquets, a cassette with a heated dish in a plate, stored under a special cover, is taken to the dining room and the waiters quickly place the finished dish to each guest;

2.Ultra Vent exhaust hood.

Unlike its predecessor, an ordinary ventilation hood, Ultra Vent not only extracts steam and odors generated in the working chamber, but also, using a heat exchanger, condenses them in a confined space and discharges them into the general drainage system. The fan automatically turns on when the door is opened.

The new umbrella greatly simplifies the supply of utilities to a combi oven located, for example, directly in the sales area of ​​a supermarket. Store visitors are not irritated by odors, and the interior is not disturbed by exhaust ventilation ducts;

3. Detergent and rinse aid.

The special RATIONAL detergent and rinse aid ensures excellent results when automatically washing CPC combi steamers with the CleanJet device and during regular washing of CD and CM models.

3. Description of the device (installation flow diagram)

Combi ovens have undergone a long evolution since the early 70s of the 20th century. Just five years ago, machines with a boiler steam generation unit were considered reputable; now they are injection-type machines. New models have a different system (Fig. 1)

Fig. 1 Technological diagram of a combi oven.

1. Device number (visible only when the door is open); 2. Safety gas flow control device (only for gas models, option); 3. Illumination of the working chamber allows you to monitor the cooking process even in a fully loaded oven; 4. The double glass door of the combi oven ensures complete thermal insulation; 5. Door handle. Tabletop combi ovens: handle with slamming function, opens with one hand. Floor-standing combi ovens: the handle can be opened with one hand; 6. Release device for separating the double glass door wings (inside); 7. Built-in self-emptying door water catcher (inside); 8. Water collector of the combi oven with direct connection to the drainage system; 9. Combi steamer legs (adjustable in height); 10. Nameplate (indicating all important data such as power consumption, type of gas, voltage, number of phases and frequency, as well as indicating the type and number of the device); 11. Control screen; 12. Electrical unit casing; 13. Central regulator; 14.Hand shower (with automatic winder);15. Guides (floor-standing combi ovens); 16. Air filter (air flow into the electrical unit).

Combi steamers allow you to perform up to 70% of the total number of all possible heat treatment operations. The main modes of the combi oven are:

1. Operating mode “Steam” (designation on the control panel).

The powerful steam generator produces hygienic, fresh steam. It is supplied without pressure into the working chamber, and the fan ensures its rapid circulation in it. Thanks to the patented control system, steam is always supplied in the amount that is actually needed for the product. In this operating mode, the working chamber temperature is set to a constant temperature of 100°C.

Can be used to prepare any food (vegetables, pasta, fruits, fish, meat, eggs, etc.). Products do not overheat, which is very important for dietary and baby food, as well as for preparing delicacies and vegetables. Delicate foods such as fish and vegetables do not lose their appearance, since their structure is not destroyed, which is almost impossible to avoid when preparing a dish in the traditional way. The time spent on steaming will be one and a half times less than with regular cooking in broth. There is no need to add water to the product, with the exception of rice and pasta.

In the “Steam” operating mode, it is possible to steam, stew, blanche, simmer without boiling, soak, cook food in vacuum packaging, defrost, and canning.

2. Operating mode “Hot air” (designation on the control panel).

Powerful heating elements heat dry air. The fan distributes it evenly in the working chamber. The oven temperature can be adjusted from 30°C to 300°C.

3. Operating mode “Steam convection” (designation on the control panel).

The control system allows you to combine both operating modes - “Steam” and “Hot air”. This combination provides the hot and humid working chamber climate necessary for particularly intensive cooking. The oven temperature can be adjusted from 30°C to 300°C. At the same time, the optimal humidity is always set in the working chamber, which prevents the product from drying out.

In this mode, food is cooked using hot air, uniformly supplied by the chamber fan, which generates a powerful current of hot air, guaranteeing uniform temperature at all points. Suitable for preparing all types of food: chops, fillets, chicken, poultry, fish, stewed vegetables, baked goods, dough, browning, etc. , as well as for reheating previously prepared foods. Hot air or heat envelops the product, binds meat protein and prevents the release of meat juice, ensuring the juiciness of the meat even at the highest temperatures. The mode is quite suitable for baking, frying, grilling and breading. There is no mixing of odors of different products in the oven because the air conveys virtually no flavors. The convection mode allows you to simultaneously cook various dishes on several levels.

Used for frying, grilling, crisp-frying or breading. This is an indispensable cooking method for all types of meat or poultry and for any kind of baking. The temperature range from 0° to 270°C allows you to carry out any classical cooking operation.

4. Operating mode “Low temperature steam” (designation on the control panel).

An electronic control system using temperature sensors maintains a preset constant temperature throughout the entire working chamber with an accuracy of one degree. Precise control and automatic regulation technology ensure the optimal cooking chamber climate for each product. The oven temperature can be adjusted from 30°C to 99°C.

5. Operating mode “Regeneration Finishing” (designation on the control panel).

Both operating modes - “Steam” and “Hot air” – are used together. At the same time, an optimal climate is created in the working chamber, in which, on the one hand, the products do not dry out, and on the other, puddles and water stains do not form. The oven temperature can be adjusted from 30° to 300°C.

6. Operating mode “Cooking with probe”.

Usually necessary when cooking large pieces, when there is no way to know the temperature inside the meat. The probe is inserted into the core of the product, and when the set temperature inside is reached, it transmits to the oven to turn off. Necessary for long-term cooking (for example, can be cooked overnight).

7. Operating mode “Regeneration”.

For preparing precooked and blast-frozen foods. Typically regeneration occurs at 80oC for 10-11 minutes. Suitable for products stored in vacuum packaging. (For vacuum packaging, a special film is used, in which you can not only store, but also regenerate products).

8. Operating mode “Combined”.

Convection vaporization mode. This mode is a combination of the advantages of steam and convection mode, which achieves a high speed of air circulation driven by the internal fan, which guarantees the correct cooking environment for all products and the ideal level of humidity. This mode makes it possible to implement technological solutions for cooking food that were previously practically inaccessible, and can only be implemented in combi ovens. Suitable for preparing all types of food. Cooking most of the classic second courses using the combined mode allows you to prepare dishes in a short time without the use of fats, without the risk of burning, weight losses are reduced by 30-50%.

9. “Warming up” operating mode.

Heating occurs due to the simultaneous operation of air heating elements and incoming steam (the amount of incoming steam is greater than in combined mode). This mode is used to restore (heat) previously prepared products while maintaining all their properties and external qualities through a combination of using steam and creating a certain temperature. Heated foods retain their appearance, smell, vitamins, weight and look as if they had just been cooked.

3.1 Principles of equipment purpose, technical diagram and operating rules

The control panel is the basis of the control system for all machine functions. The main difference between panels from different manufacturers lies mainly in design. For different types of catering establishments, combi ovens typically offer three types of panels. The more complex the control panel, the more auxiliary functions it has, the higher the price of the combi oven.

Mechanical type of control - the panel is easy to operate and does not intimidate personnel with an abundance of buttons and indicators. It has a limited range of combi steamer functions.

Electromechanical control type is relatively easy to operate. Combines mechanical control knobs with touch buttons. Includes many functions that can expand the capabilities of the device. This type of control contains additional indicators - temperature, time, climate, etc.

In the electronic (computer) control type, the control panel is similar to a personal computer with a liquid crystal display. All functions of the combi oven (setting temperature, climate, cooking time, etc.) are displayed on the display. Although seemingly complex at first glance, upon closer examination it turns out to be extremely simple. And it simplifies the process of controlling the device as much as possible. An important feature of a good combi oven is clear controls, what is called an “intuitive interface” (especially if the menu is not Russified). A high-tech but expensive solution is a touch screen. All combi steamers are made of food grade stainless steel.

The working chamber of the machine is a semi-sealed chamber with rounded corners. The chamber becomes airtight due to the tight fit of the rubber seals on the body of the device to the door of the combi oven. Air convection distributes heat evenly throughout the working chamber, maintaining the same temperature at different levels. Inside the working chamber are located; fan, around it (usually ring) heating elements or gas heating elements.

At the bottom there is a drain hole for condensate.

The glazed door allows you to observe the cooking process in the working chamber. The ovens are equipped with double glass doors, while the inner glass is thermally inert with a cooling air recirculation channel. This design minimizes heat emission into the external environment. The circular principle of door opening makes it possible to wash both glasses on both sides and also prevents the formation of condensation. There are doors whose inner glass is treated with a special grease-repellent compound to make it easier to clean the combi steamer after use.

Combi oven doors come in different types. The operating principle of a standard locking device (the so-called rotary principle) is as follows: when the door is closed and the handle is turned to the locking position, the rods, due to the movement of the mechanism, come out of their main hidden position and engage with the corresponding fasteners on the body of the combi oven. Thanks to this, the door closes quite tightly and ensures the tightness of the working chamber. Quite often there are models of combi steamers that use a push-button door closing principle. In this case, the door presses the locking button and thus closes hermetically. The lever closing principle is that the lever located on the door is captured by a locking device on the wall of the machine.

The bottom of the working chamber is made in the form of a bathtub with a recess and a drain hole connected to the sewage system. Door water collector is a small metal box used to collect condensed moisture from the combi oven door when it is opened. This is quite a useful addition. Condensation does not fall on the floor, but is removed through a special chute into a tray. The combi oven may have additional functions such as rapid cooling of the chamber before opening the door.

The combi oven has the ability to cook food using a temperature probe (thermal needle), which monitors the temperature in the core of the cooked product. Using this method, you do not need to set the cooking time, just set the temperature of the finished product. Food will not be cooked longer than necessary. Sometimes suppliers draw customers' attention to the number of touch sensors in a temperature probe. Multi-zone temperature probes are considered the most effective. It determines the temperature at several points, and regardless of whether the temperature probe is installed correctly, it gives correct readings. Reversible (multi-directional) fan - creates uniform circulation of hot air throughout the chamber, and, therefore, uniform heat distribution. Thanks to the presence of several fan speeds, you can prepare even the most delicate dishes. Adjusting the oven power (1/2 power) will allow you to save energy when the working chamber is not fully loaded.

Special adjustable feet allow you to firmly install the combi steamer on any surface, in an exact horizontal position.

Gastronorm containers and grates made of stainless steel with dimensions from 1/3 to 2/1 and depth from 20 to 150 mm are used for basic heat treatment processes. Perforated gastronorm containers of various sizes are recommended for use when steaming. Enameled gastronorm containers provide excellent results when frying breaded products and preparing a variety of casseroles. Perforated aluminum pans with Teflon coating are well suited for baking bakery and confectionery products. Special stands for frying chickens, ducks and a spit for cooking suckling pig allow you to achieve excellent quality and a memorable appearance.

Stands are used for stable and operator-friendly arrangement of combi steamers on 6 or 10 levels. There are open stands and those with doors. Most models include guides for placing grates and gastronorm containers with preparations and ready-made dishes.

Based on capacity and dimensions, combi steamers are divided into small, medium and large.

Small ones. These include devices whose capacity is designed for 2-6 GN 1/1 gastronorm containers.

Average. These are combi steamers with a capacity of 10 to 12 GN 1/1 gastronorm containers, as well as devices for 6 GN 2/1 gastronorm containers.

Big ones. Large-capacity combi steamers include machines designed for up to 20 GN 1/1 gastronorm containers, as well as 10-, 12- and 20-capacity machines using GN 2/1 gastronorm containers. Place the gastronorm containers into the working chamber of the machine on the guides. In most combi ovens, the guides for installing gastronorm containers are a single removable structure. This was done for ease of maintenance, sanitary processing of the working chamber, as well as for the possibility of installing structures using special carts.

3.2 Justification for the choice of main and auxiliary equipment

A heater is used as an auxiliary equipment in a combi steamer.

Heaters are designed to heat air in ventilation systems, air heating, air conditioning, as well as in drying installations using hot, superheated water or steam supplied from external sources of air and heat supply. Water temperature - up to 180°C; steam temperature - up to 190°C; operating pressure - up to 1.2 MPa (12 kgf/cm2). The air must contain the maximum permissible content of chemically aggressive substances with a dust content of no more than 0.5 mg/m3 and not contain sticky substances or fibrous materials.

The heater has heat-dissipating elements, which are made of a steel tube and aluminum knurled fins with a diameter of 39 mm. The pitch between the ribs is 3mm. Among the currently used heaters are KSK, KVS/KVB, KPSK.

Operating conditions for KSk and KPSk. Should not be installed on objects that create external vibration with an RMS value of more than 2 mm/s. In winter, commissioning should be carried out with a temperature rise rate of no more than 30 °C per hour. For KPSk: the heater is not allowed to operate on flying steam. The condensate level should not be higher than the bottom row of heat transfer tubes. In order to avoid a through (flight) breakthrough of steam and at the same time not to have high velocities causing erosion of the walls of the heat transfer pipes, it is necessary to install condensate drains of the appropriate number at the condensate drain (at a distance of at least 300 mm from the lower pipe of the heater). The removal of condensate must exclude the possibility of defrosting the air heater and the occurrence of water hammer when the load changes.

4. Technological and thermal calculations of the device

The paper presents the following main parameters of the coolant and product:

1) φ 0 – initial relative air humidity = 87%;

2) φ 2 – final relative air humidity = 25%;

3) t 0 – ambient temperature = 20°C;

4) t 1 – product heating temperature = 180°C;

5) t 2 – product cooling temperature = 63°C;

6) X n – initial moisture content of the product = 75%;

7) X k – final product moisture = 40%;

8) G n – equipment productivity = 6.5 kg/h;

9) overall dimensions of the equipment:

H – height = 0.75 m;

d out – outer diameter of the heater = 0.5 m;

l – length = 0.86 m;

N w – width = 0.76 m.

4.1 Technological calculation.

Based on the initial parameters of the product and coolant, we draw up a material balance of the thermal process.

Let us determine the mass of moisture W removed during thermal exposure.

W = G n – G k, kg/h = kg/s (1)

For all material subjected to heat treatment, the initial amount of product:

G n = G k + W (2)

Based on absolutely dry matter in the processed material:

G n = G k (3)

Let's determine the productivity of the finished product:

G k = G n, kg/h = kg/s (4)

2.7083 kg/h = 0.000752 kg/s

Substituting the value of G k into equation (1), we obtain:

W=G n =6.5∙=3.7916 kg/h=0.00105 kg/s (5)

W=G k =2.7083∙=3.7916 kg/h=0.00105 kg/s (6)

Equations (5) and (6) are the basic equations of the material balance of the thermal process.

Let air with moisture content X 0 (%) of dry air be supplied for heat treatment, and L be the flow rate of absolutely dry air (kg/h). The same amount of absolutely dry air leaves the heat exchanger (in the absence of air loss), and the moisture content changes to X 2 (%) of dry air. The mass of moisture evaporating from the material in the heat exchanger is W (kg/h).

A) partial air pressure p 1 = p o, kPa, based on the values ​​of φ 0 = 87% and t 0 = 20 ° C;

Steam pressure;

φ – relative air humidity;

Saturation pressure (see Appendix D).

B) partial air pressure p 2, kPa, based on the values ​​of φ 2 =25% and t 2 =63°C;

0.25 ∙ 22.974 = 5.7435 kPa

where p atm – atmospheric pressure

D) enthalpy of dry air I 0, kJ/kg

,

Where is the heat capacity of air;

enthalpy (see Appendix D).

E) enthalpy of moist air I 2, kJ/kg

G) from the found values ​​p 1 = and t 1 =200°C we determine I 1, kJ/kg

Based on these parameters, we determine the specific air consumption for evaporation of 1 kg of moisture from the material using the formula:

e = , kg/kg

e = 1 / (0.0383-0.01304) = 39.59 kg/kg (7)

L = We = 3.7916 39.59 = 150.1094 kg/h = 0.0417 kg/s (8)

4.2 Thermal calculation

We compile a heat balance:

1. Arrival of heat:

a) with outside air:

Q 1 = L I 0 , J/h = J/s (9)

Q 1 =150.1094 ∙ 53165.1 = 7980581.2619 J/h /3600 = 2216.8281 J/s

b) with wet material:

Q 2 = G n t n c p, J/h = J/s, (10)

where t n = t 0 = 20 degrees;

c p – heat capacity of the product, c p = c m, J/(kg deg)

Q 2 = 6.5 ∙ 20 ∙ 1059.311 = 137710.43 J/h = 38.2529 J/s

c) in the main heater:

Q 3 = Q k = L (I 1 – I 0), J/h = J/s (11)

Q 3 = Q k = 150.1094 (216923-53165.1) = 24581600.1143 J/h/3600 = 6828.2223 J/s

2. Heat consumption:

a) with exhaust air:

Q 4 = L I 2, J/h = J/s; (12)

Q 4 = 150.1094 ∙163.3759 = 24524.2583 J/h / 3600 = 6.8123 J/s

b) with finished material (product):

Q 5 = G k c 2 t 2 , J/h = J/s, (13)

where c 2 is the heat capacity of the product after heat treatment,

s 2 = s // m = 635.9866 J/(kg deg);

Q 5 = 2.7083 ∙ 635.9866 ∙ 63 = 108513.8781 J/h / 3600 = 30.1427 J/s

c) when loading and unloading the product (during transportation of the product):

Q 6 = W c in ·θ, J/h = J/s, where (14)

θ= t 2 ; c in – heat capacity of water, J/(kg deg), determined according to the nomogram (see Appendix B);

с в = 1.005 kcal/kg∙С о = 4.21 ∙ 10 3 J/kg∙С о

Q 6 = 3.7916 4.21 10 3 63 = 1005646.068 J/h / 3600 = 279.3461 J/s

d) heat loss (Q 7) is determined from the heat balance

Heat balance:

Q 1 + Q 2 + Q 3 = Q 4 + Q 5 + Q 6 + Q 7 (15)

Q 1 + Q 2 + Q 3 - Q 4 - Q 5 - Q 6 = Q 7

Q 7 = 7980581.2619 + 137710.43 + 24581600.1143 – 24524.2583 - 108513.8781 - 1005646.068 = 31561207.6018 J/h / 3600 = 8767.0021 J/s

Let us consider sequentially all stages of calculating heat loss.

1. Heat loss to the environment:

a) average temperature difference between the media (in the apparatus chamber and in the environment)

along the length of the device:

tav = , °С (16)

tav =

b) temperature difference between the media at the ends of the apparatus:

t´av = t 1 – t 0 , °С (17)

t´av = 180 – 20 = 160°С

t´´av = t 2 – t 0 , °С (18)

t´´av = 63-20 = 43°С

c) heat loss intensity:

Along the length of the device:

q dl = K t avg, where (19)

K – heat transfer coefficient (for all walls of the apparatus), K ≈ 0.7

q dl = 0.7 89 = 62.3 kcal/(m 2 h) ∙ 4.19 ∙ 10 3 = 72.5103 J/(m 2 ∙s)

from the ends of the device:

q´t = K t´avg (20)

q´t = 0.7 160 = 112 kcal/(m 2 h)∙4.19∙10 3 /3600 = 130.3556 J/(m 2 s)

q´´t = K t´´avg (21)

q´´t = 0.7 43 = 30.1 kcal/(m 2 h) ∙4.19∙10 3 /3600= 35.0331 J/(m 2 s)

d) heat loss to the environment:

q os = (q in · f in + q sweat · f sweat + q floor · f floor) · , J/kg, (22)

q os =(72.5103·0.57+130.3556·0.6536+35.0331·0.6536) = 142313.2622 J/kg

where q in, q sweat, q floor are the rates of heat loss into the environment, calculated separately for the vertical walls of the apparatus, ceiling and floor;

f in, f sweat, f floor – the surfaces of vertical walls, ceiling and floor, determined based on the geometric dimensions of the apparatus;

f in = N · N w – for heat exchange processes with a flat heating surface, m 2, where:

H – height, m; N w – width, m;

f in = 0.75 0.76 = 0.57 m2;

f sweat = l N w – for heat exchange processes with a flat heating surface, m 2,

where l is length, N w is width

f sweat = 0.86 ∙ 0.76 = 0.6536 m2;

In this calculation, the following equality is observed: f floor = f sweat, m2, and the intensity of heat loss to the environment is also determined in certain units of measurement sequentially:

q in = q dl = 72.5103 J/(m 2 s);

q sweat = q´t = 130.3556 J/(m 2 s);

q floor = q´´t = 35.0331 J/(m 2 s);

W – moisture mass = 3.7916 kg/h = 0.00105 kg/s

2. Heat loss for heating the material:

, J/kg, (23)

where с´ m is the heat capacity of the raw material, determined as follows:

s´ m = s m + (1 – s m), J/(kg deg), (24)

s´ m = 1059.311+(1–1059.311)= 265.5778 J/(kg deg)

where c m = c p is the heat capacity of the product, determined by the formula:

with n = 41.87 · , J/(kg deg), (25)

where a is the initial moisture content of the product X n, %;

with n =41.87 = 1059.311 J/(kg deg)

с´´ m = с m + (1 – с m), (26)

s´´ m =1059.311+(1–1059.311)= 635.9866 J/(kg deg)

where с // m – heat capacity of the product after heat treatment, J/(kg deg)

ν is the average temperature of the material subjected to heat treatment, determined as follows:

ν, °С; (27)

ν °C

Х к – final product humidity, 40%;

G 2 = G k = 2.7083 - mass of the product after heat treatment, kg/h;

G 1 = G n = 6.5 – initial addition of product, kg/h.

3. Amount of heat loss per 1 kg of evaporated moisture:

Σq = + q os, J/kg

Σq = + 142313.2622 = 188402.42 J/kg

Heater calculation

At the first stage, we determine the density of the air passing through the heater:

ρ = ρ 0 , kg/m3, (28)

where ρ 0 is the standard value of air density under normal conditions, kg/m3:

ρ 0

where M air is the molecular mass of air, g/mol

T 0 – air temperature under normal conditions, 273 K

T – ambient air temperature, K: T = t 0 + 273 = 20 + 273 = 293 K

р 0 – partial air pressure under normal conditions; 760 mmHg Art.

р – partial pressure of ambient air, 735 mm Hg. Art.

Q p = F side (t st – t 0) α, J/s, (30)

where F side is the side surface of the heater drum;

t st – temperature of the heater drum wall from the outside t st = t 4 =35,°C;

t 0 – ambient temperature = 20°C;

α is the heat transfer coefficient from the wall of the heater drum into the environment,

Heat loss is determined step by step as follows:

1) Determine and characterize the mode of movement of ambient air relative to the outer surface of the heater drum (according to the Reynolds criterion):

where l is the height of the apparatus, l = H = 0.75 m;

ρ in – air density at a temperature of 20 degrees, ρ in = ρ 0, kg/m3;

ρ in kg/m 3

where ρ 0 is the standard value of air density under normal conditions, kg/m 3, determined by formula (32), T 0 is the air temperature under normal conditions, 273 K; T – ambient air temperature, K: T = t 0 + 273 = 293 K;

μ – air viscosity at temperature t 0, ,

µ = 0.018·10 -3 =0.000018;

ω in – relative speed of air movement:

ω in = , m/s, (32)

ω in = 0.0262 m/s

where d out is the outer diameter of the heater, m;

n – number of heater drums, n = 1.

Re=

2) Heat transfer coefficient from the wall of the heater drum into the environment due to forced convection:

where Nu is the Nusselt coefficient, Nu = 0.018 Re 0.8 ε i,

Nu = 0.018 0.8 1.5 = 8.4522

where ε i is the coefficient of geometric dimensions, ε i = ;

λ – thermal conductivity of air, λ = 0.0261;

l = H =0.75 m – apparatus height

α to

3) Radiation heat transfer coefficient:

α l , , (34)

where ε is the degree of emissivity for the surface of the heater drum, ε = 0.95;

с 0 – black body emissivity coefficient, с 0 = 5.7;

T st – temperature of the apparatus wall, T st = t 2 + 273, K;

T st = 63 + 273 = 333, K

T 0 – ambient air temperature, T 0 = t 0 + 273, K;

T 0 = 20 + 273 = 293, K

t st = t 2 = 65 °C,

α l

4) Heat transfer coefficient from the heater drum wall to the environment:

α = α k + α l, (35)

α = + = 6.2221

5) The required thickness of the insulation layer with the thermal conductivity of the insulating material:

λ 2 = λ m = 0.076

On top of the insulation with a thickness of δ 2 there is a casing made of sheet iron. The thickness of this casing is δ 3 = 1 mm = 1 10 -3 = 0.001 m.

δ 1 – standard insulation thickness together with the casing, δ 1 = 12 mm = 0.012 m.

The temperature of the inner and outer sides of the drum walls has the values ​​t 1 and t 2:

t 1 = t 2 ≈ 60 degrees;

t 3 = t 4 ≈ 35 degrees – temperature of the walls of the protective casing.

a) Determine the specific heat flow:

q e = π · d nar · q nar = π · d nar · α · (t 4 – t 0), (36)

q e = 3.14 ∙ 0.5 ∙ 6.2221 ∙ (35-20) = 146.5305 W/m

δ 2 = δ 1 - δ 3 = 0.012 - 0.001 = 0.011 m

6) It is necessary to clarify the outer diameter of the heater drum:

d n = d nar + 2 δ 1 + 2 δ 2 + 2 δ 3 , m (37)

d n = 0.5+ 2 0.012 + 2 0.011+ 2 0.001 = 0.548 m

Then the outer surface of the drum is determined:

F side = π d n l, m 2, (38)

where l is the height of the apparatus = 0.75 m

F side = 3.14 · 0.548 · 0.75 = 1.2905 m2

Heat loss to the environment due to the air heater is determined by formula (33):

Q p = α F side (t 4 – t 0) (39)

Q p = 6.2221·1.2905∙(35 – 20)= 120.4443 J/s.

After calculations have been made based on the values ​​of the outer surface of the heater drum, we select the heater model (see Appendix B): KFB -14.

Conclusion

In this course work, calculations were carried out, where we compiled the material balance of the thermal process, based on the initial parameters of the product and coolant. The purpose of compiling a material balance of the thermal process was to determine the mass of moisture W removed during thermal interaction. Also in the calculation part, the thermal load of the apparatus was determined, the calculation of the heat transfer surface for a given flow rate of the heated product and its temperature, the steam consumption for heating and heat treatment of the product, and calorifier calculations.

In calculating the heater, we determined the Reynolds criterion, as a result of which we characterized the mode of movement of ambient air relative to the outer surface of the heater drum as laminar.

The combi oven is one of the best equipment in the food industry. Combi ovens allow the cook to prepare food using a variety of cooking modes, especially steam. The combi oven is reliable, easy to use, easy to clean and maintain, and has an ergonomic design.

This is a device of the future, perhaps not only on an industrial scale.

Bibliography

1. Plaksin, Malakhin “Processes and apparatus of food production” - M.: Higher School, 1997.

2. www.parokonvektomat.ru

5. www.SvarVent.ru

6. www.Easycombi.ru

7.www.equipnet.ru

8. Budasova S.A. Guidelines for laboratory work in the course "Physical and technical foundations of refrigeration processing of food products." Part 1. – Novosibirsk: NSTU, 2002. – 31 p.

9. Rogov I.A., Kutsakova V.E. and others. Cold canning of food products (thermophysical fundamentals). - M.: "Kolos", 1999. - 176s

10. G.G. Dubtsov “Technology of cooking”. M.: "Academa". 2002

11. N.I. Kovalev, M.N. Kutkina, V.A. Kravtsov “Technology of cooking”. M.: “Business literature, Omega

Applications

Appendix A

"Ramzin diagram"

Appendix B

“Nomogram for determining the heat capacity of liquids.”

Appendix B

Table of steel heaters models

Appendix D

Table of dry saturated steam and water by temperature

The combi oven itself is a multifunctional device that combines a grill, oven, and steamer. This device has many steam supply modes, thanks to which the combi steamer can easily replace most kitchen appliances.

Operating principles of a combi oven

Today, a combi oven can perform about 70% of the functions that are used in a professional kitchen, thanks to this it is possible to replace half of all heating equipment. Thanks to the hot air circulation and steam circulation method, the combi oven has this functionality. In addition, there are many modes of both individual processing, or steam, or air, or a combined method. Thanks to this, the combi oven has basic operating modes: cooking steam dishes, convection and a combined method.

There are several types of combi steamers, depending on the type of steam generation system installed. Boiler - this is when the process of steam generation occurs in a steam generator. Injection - this is when steam is generated directly in the working chamber. And as usual, experts cannot agree on which combi oven works best. Some advise using boiler systems (the accuracy of the set parameters of the generated steam), while others choose injection systems (maintenance is cheaper).

Unique functionality of the combi oven

In the professional kitchen of a restaurant or cafe, a combi oven can become an indispensable attribute. If you have a combi oven, you don’t have to worry about buying many other appliances. This is a very important factor that will help save money and work space. In addition, the combi oven has been tested several times and all food cooked in it practically does not lose its beneficial properties and vitamins.
The convection steam oven is so multifunctional that chefs can cook fried, baked, steamed dishes, as well as baked goods in it. For example, if a combi oven is installed in the kitchen of a restaurant or cafe, then there will no longer be a need for an oven, various types of ovens, a deep fryer and much other heating equipment. It follows that a combi oven is the most convenient method of solving problems in the professional kitchen of a restaurant or cafe. It is worth thinking about buying a combi oven at the initial stage, this will help save money, effort and time.

Advantages of a combi oven

The main advantage of this multifunctional device is the fact that food is prepared in it much faster than in traditional equipment. In comparison, a combi oven will cook food 30% faster. In addition, several dishes can be cooked simultaneously in one oven. The result is very tasty and healthy food. There is a large selection of combi ovens that differ in functions and power. You can study them in more detail and select them here http://www.kobor.ru/katalog_teplo_par.html. Each device has a detailed description of each function and preparation.

Another advantage of the convector steamer is the fact that it significantly reduces the labor costs that are often spent on cooking. In addition, the product loses a minimal amount of weight during cooking. Experts have conducted some research, which found that using a combi oven reduces energy costs by 20%. Cleaning the cooking chamber does not require much effort, and some devices have a self-cleaning function.

What can you cook in a combi oven?

The answer is simple. You can cook anything in it. The machine, which was invented by German engineers, has all kinds of heat treatment methods applied to any type of food. In particular, you can fry or steam cook, stew, bake and many other functions. This device can be ideal even for a professional chef. First of all, because a combi oven can cook most of the dishes that are offered by the establishment.

What is important to remember when buying a combi oven? The first thing you need to do is learn how to use it. If you have doubts and think that the equipment will sit idle in the kitchen, then cast aside these doubts. In addition, specialists constantly provide training on how to operate the combi oven. Even the most experienced chefs will be able to derive some benefits for themselves. The knowledge gained is necessary so that you can use all the functions of the combi oven to the maximum (its capabilities, description of functions, operating rules, troubleshooting methods).

Service maintenance of combi ovens. Like any other equipment, a combi oven also needs regular maintenance; in addition, proper installation of the equipment will play an important role. In addition, the service department can take care of your combi oven at any moment.

Repair of combi ovens. Surely many have experienced that the necessary equipment breaks down at the most inopportune moment. In such cases, a quick and timely response will play an important role. You should not call friends or colleagues, or search the Internet for a solution to this problem. If the combi oven was purchased from us, then it will be enough to dial our customer service number.

How to choose the right combi oven?

To select a combi oven, you need to consider some important parameters. Firstly, this is the size of the purchased equipment. For example, if an establishment has few seats and the flow of visitors is kept at an average level, then a six-level combi oven will be sufficient. For a large restaurant, you will need a combi oven with ten levels (a 10-level “Rational” model may be suitable), you can install several small combi ovens. If the company has a focus on large banquet events, then it is worth choosing a 20-level model.

An important factor will be the accurate determination of the dimensions of the combi oven, in the future this will significantly reduce the loss of resources (electricity, water, cleaning products). If the oven is too large, it will take up useful kitchen space. If you often use an incomplete chamber load, this can lead to disruption of stable performance.

In the control system, the combi steamer should not be confusing to operate. For convenient washing there is a special hand shower. The combi steamer must be equipped with a drainage drain into the sewer. Before you buy, you should think about the ease of opening the door.

In what modes can combi steamers operate? Due to the fact that the combi steamer is capable of operating in hot air, steam or a combination of these modes, this makes it possible to cook, fry, bake and steam in one working chamber.

Thanks to different steam modes, the combi oven ensures uniform cooking and preservation of mass. If the convection oven operates in hot steam mode, the consumption of oil and spices is significantly reduced.
If you turn on the convection mode, the equipment can be used to prepare cutlets or fillets. Due to the fact that hot air directly enters the working chamber, it envelops the meat product, which allows protein to bind. In turn, this helps retain liquid in the product. Thanks to this, the dishes remain juicy and tasty.

Often a steam convection oven is used in combined mode. Convection, together with steam, creates a moist and hot environment inside the chamber, which ensures uniform frying and protects the product from drying out.
Today, manufacturers of steam convection ovens produce many devices that have different performance and characteristics. Many establishments and restaurants use a 10-level programming system.

Advantages of combi steamers

• The weight of meat products is practically not lost during cooking.
• All cooked vegetable dishes retain nutrients.
• Less fat consumption up to 95%
• Electricity consumption is reduced by 60%.
• Less water consumption, approximately 40%.
• 30-50% less cooking time.

In addition, you can significantly save kitchen space due to the fact that a steam convection oven replaces most heating appliances.

A combi oven is an installation that acts on the food product being processed, both through convection of heated air and using dosed portions of water steam.

This combination gives the finished dish a delicious crispy crust, retaining moisture, vitamins, proteins and nutrients inside the product.

Convection processes significantly speed up the cooking time, which is important in continuous culinary production.

Nowadays, a rare industrial kitchen, an educational institution canteen, a cafe or a mini-bakery can do without this multifunctional device.

Principle of operation

The operation of a steam convection oven is based on the principle of combining the effects of a conventional oven with forced circulation of air flows and a double boiler, in which food is cooked using steam.

The food product is subjected to double heat treatment. Using this method, you can not only prepare baked goods, but also quickly defrost meat, fish, minced meat, and also reheat ready-made dishes.

The difference between a combi oven and a convection oven

To an inexperienced user, these devices may seem absolutely identical, however, this is a biased point of view. The difference between a combi oven and a convection oven will be discussed below.

Common properties, due to which they are often confused, of a combi oven and a convection oven are:

• Forced supply of hot air to the product using a special fan.
• Semi-automated or automated production process.
• High speed of obtaining the finished product.

But the main difference between a combi oven and a convection oven is its ability to generate water vapor in a dosed manner inside the working chamber. A convection oven does not have this capability.

That is why steam convection ovens have several operating modes, such as: dry treatment with hot air, treatment with heated steam, as well as a combined mode of cooking a product or dish.

Device

The main components of the combi oven are:

Species and types

The whole variety of combi steamers that modern industry produces can be classified according to several main characteristics.

According to the method of steam formation

There are boiler and injection steam-convection installations. They differ from each other in the way they supply heated steam into the working space of the furnace:

By type of control

Combi steamers can be divided into three main groups according to the type of control:

• Mechanical. The controls of such a device consist of knobs and toggle switches. They are used on inexpensive models, are reliable in operation and rarely fail.
• Electromechanical. This type of control combines mechanical toggle switches and touch electronics. It is easy to learn for beginners and is most common in convection steam units. The number of breakdowns does not exceed the mechanical control method, but the electronics can sometimes malfunction.
• Electronic. The oven is controlled using a special remote control; it is possible to program various functional modes; there are almost no touch buttons. This is a modern and high-tech way to control a combi oven.

By capacity

Based on the volume of products loaded into the oven, they are divided into:

1. Small installations (2 – 6 levels of loading grids or trays), medium (6 – 10 levels) and large (up to 24 loading levels).
2. Small combi steamers are used in households, as well as in small private catering establishments.
3. Installations of medium and large volumes have found their application in large institutions and food factories. Accordingly, furnaces with a large chamber volume require significant energy costs for their maintenance.

By energy carrier

There are both gas and electric combi steamers. Gas units are more expensive and they are not available with mechanical controls. Installations powered by electricity have become more widespread.

Advantages and disadvantages

The main advantages of steam convection ovens are:

• Ability to control the level of humidity and temperature inside the installation.
• High speed of cooking or baking products.
• Uniform heating of the dish, preserving vitamins and beneficial microelements in it.
• Possibility of preparing large volumes of products.
• Small dimensions of such installations.
• Low electrical energy consumption.
• Ease of control (especially for mechanically controlled furnaces).

The disadvantages of combi ovens include:

• Dependence of the installation on electricity or gas communications.
• High cost of medium or large installations.

How to choose?

Now the market offers buyers combi steamers of both domestic and foreign production from Italy, Sweden, Germany, the USA and other countries.

Criterias of choice

You need to choose a combi steamer for the needs of your production or for home use based on the type of energy carrier on which it will be operated, the expected power and the amount of product produced.

In order to accurately comply with technological conditions, it is necessary to carefully read the technical documentation for the product, what temperature and humidity conditions can be produced by a steam convection oven, and how quickly this or that stage of processing of raw materials or product occurs.

It is necessary to take into account the personal or collective financial capabilities of the catering establishment, as well as the projected payback period for new equipment.

Review of models for home

Models for industry

Conclusion

In the modern food industry and cooking, it is difficult to do without steam convection ovens. They are easy to maintain, fast in operation and economical in energy consumption.

There are also “home” versions of combi ovens. When choosing such devices, you need to be guided by your production needs, capacity and dimensions of such devices.

Specialists from a German company worked to create new equipment for a professional kitchen. The result of the work was highly efficient combi steamers that still save time, electricity, and water. But the main advantage was the ability to preserve the beneficial properties of the product. Multifunctional equipment appeared on the market in 1976. They were introduced by Rational.

The combi oven is a universal oven. Products are cooked in it under the influence of heat, which is transmitted from heating coils using a fan. The cook just needs to set the necessary parameters - temperature, humidity, cooking time - and the combi steamer will begin the process of preparing the product.

Types of combi steamers

Based on the type of control, combi steamers are divided into mechanical, electronic and electromechanical, or combined.

This feature of kitchen equipment determines its price.

Mechanical

Disadvantage: limited number of functions. Plus - a simple control panel that does not intimidate staff with an abundance of buttons that can get confusing. This type includes combi steamers from the German manufacturer Convotherm.

Electronic

They resemble a computer that can cook. All functions are shown on the display. Just touch the screen to set the required program. The main thing is to figure out how to do it.

For a cook who is not afraid of technology, such a convection oven will become a real assistant in the kitchen. But the modern interface and touch screen solution increase the cost of the equipment.

An example of such a miracle technology is the combi steamer model of the Italian manufacturer Apach A1/6 LD with a touch control panel. The programming range of up to 99 programs allows you to enter data about the method of preparing the dish in advance.

Combined

The golden mean and the best option when choosing equipment for a professional kitchen. Here you have both mechanical control knobs and touch buttons. Combi ovens of this type of control are equipped with additional indicators of time, climate, and temperature.

The Italian combi oven Alphatech REV 051M belongs to models of electromechanical control type.

Gas and electric

Based on the energy source, gas and electric devices are distinguished. Rational combi steamers, available in two versions, are popular. They may not differ at all in size, equipment, or power. The only difference is in the power source.