Purpose and classification of digester boilers. Electric food boilers - features, operating principles and differences Food boilers

Types of this equipment

Today, there are three types of digester boilers on the equipment market:

1. electrical;
2. gas;
3. steam.

Electrical

Electric boilers are the most practical equipment, which is intended for preparing a variety of dishes. They are used primarily in catering establishments that require food preparation in required quantities.

The minimum volume of electric boilers is sixty liters. This type of device operates by electrical energy. Such boilers can have both a fixed and tiltable cooking vessel, as well as a system for automatic control. For comparatively large establishments There is equipment with a volume of up to three hundred liters.

Gas

Food kettles are no less popular. gas type. They are very widely used on an industrial scale. These devices provide direct heating of the housing walls in the cooking vessel.

The equipment is practically no different from electric models, however, their main advantage is that it can only work when connected to a gas pipeline.

You should also take into account the fact that gas appliances heat the water in the tank much faster.

Steam

The design of the steam digester boiler includes a special vessel for cooking, reliably fixed inside a metal case. There is a lid over the cooking container. When lowered, it is pressed tightly against the body, and when slightly raised, it can be secured at any convenient angle. The lower half of the boiler is equipped with a steam-water jacket. The liquid is heated by steam, which enters the steam bath from an external steam generator.

KPEM-250 from Chuvashtorgtekhnika has the function of tipping, as well as cooling and stirring. The device has a fairly easy-to-use software control, through which you can configure any cooking parameters in a few seconds. The main advantage is the ability to control the temperature regime. Its market price is from 130,000 rubles.

User review: “Perhaps the best thing about this cauldron is that you can adjust the cooking temperature. But in general, it was chosen because of its convenience program control».

KPEM-100 OR

Cooking boiler KPEM-100 OR "Chuvashtorgtekhnika" (Russia). The container heats up in about forty minutes. The volume of the digester is 100 liters. The cooking temperature range is from 0 to 100 °C. The boiler can be tilted manually at an angle of 100°. On the technical market it costs from 150,000 rubles.

The Abat KPEM-160 boiler is manufactured by Abat, Russia.

The volume of the vessel for preparing soups, cereals and other dishes is 160 liters. It is characterized by the presence of three operating modes, so it is possible to smoothly change the heating mode of the liquid, which is carried out thanks to the steam jacket. When removing a cooked dish, the lid can be secured in the upper position. The drainage is very convenient due to manual drive, overturning the container. The boiler costs about 100 thousand rubles.

Feedback from the head of the enterprise: “I’m pleased with the choice. Easy to use, high quality, reliable."

KPE-250

The KPE-250 boiler is produced by Penzmash OJSC. It is made of stainless food steel, volume 250 liters. It is stationary and belongs to electric type. The boiler is equipped with a leak-proof lid and a round cooking vessel. Its price is 125,860 rubles.

User review: “The volume of the boiler is impressive. This was the main factor when choosing equipment.”

KPE-100

The electric digester boiler KPE-100 from Penzmash OJSC has a volume of 100 liters. The liquid in the vessel is heated in 50 minutes due to the steam jacket. Market price from 10 to 35 thousand rubles.

User review: “The price fully corresponds to the quality of the equipment. The boiler is ideal for both large and small businesses.”

KPE-160

The electric digester boiler KPE-160 is supplied to the equipment market by the Russian plant Penzmash OJSC. It differs from the previous model only in its volume of 160 liters. You can purchase equipment for about 115 thousand rubles.

Feedback from the owner of the enterprise: “Both I and my employees are completely satisfied with the performance of this boiler.”

Rules for operating digester boilers

First you need to make sure the health of the digester. Then it is connected to a source of electricity, and turned on immediately before the start of cooking. While the equipment is operating, it is prohibited to open the lid earlier than five minutes before the process is completed. The lid must be closed with all special locking levers.

Food boilers – irreplaceable helpers in kitchens serving large numbers of people. However, you should carefully select the device model and use it correctly.

Rules for operating digester boilers

Tilting boilers

Electric cooking boilers for functional containers (FE)

Steam digester boilers

Non-tipping boilers. Design, principle of operation

Food boilers. Schematic diagram

General information. Classification of cooking equipment

8. Food boilers from Metos and Falcon

1. General information. Classification of cooking equipment

Cooking is the main method of heat treatment food products. It can be produced in liquid (water, broth, milk, etc.) or steamed. When cooking, the liquid medium is heated to boiling temperature and the product is kept in it until cooked. The duration of heating depends on the thermophysical properties of the product (heat capacity, density, thermal conductivity), its geometric dimensions and shape.

The product is considered cooked when the temperature in its center reaches 98-100 °C. The heat flow during the preparation of a product is directed from its surface to the center. The main type of heat transfer is thermal conductivity. The thermal conductivity of a product depends on its moisture content. The higher the moisture content in the product, the higher the thermal conductivity coefficient. When the moisture content of the product is 95-98%, its thermal conductivity is approximately equal to the thermal conductivity of water. At a temperature of 100 °C, the thermal conductivity of water is 0.68 W/(m K). The thermal conductivity of most food products ranges from 0.12 to 0.58 W/(m K). Low thermal conductivity (0.12) is typical for products with a moisture content of 10-12%, i.e. for dry products. The thermal conductivity of water is considered quite high compared to the thermal conductivity of air, it is approximately 30 times greater.

In order to quickly cook dry foods, such as peas and beans, they need to be soaked in water. Soaking beans leads to the absorption of moisture and removal of air, as a result of which their thermal conductivity increases by 3-4 times and the cooking time is reduced by approximately the same amount. The duration of soaking legumes depends on the water temperature: the most optimal temperature is 45-50 °C. At this temperature, the recommended soaking time is from 4 to 12 hours.

Bringing the product to readiness is accompanied by many physical and chemical changes, in particular, a change in moisture content. A decrease in moisture in the product leads to a decrease in the coefficient of thermal conductivity and a decrease in the rate of propagation of heat flow through the layers of the product that has undergone heat treatment (layers located closer to the surface). This lengthens the cooking time of the product. Therefore, one of the simplest and most effective ways to speed up the heat treatment of a product is to grind it.

Cooking of products in an atmosphere of saturated steam (heating with “hot steam”) occurs in steam ovens. Saturated steam, enveloping the product, comes into contact with it and condenses, releasing latent heat of vaporization, due to which the product is brought to readiness. Cooking products in a steam atmosphere is faster than cooking the same products in water if their geometric dimensions and shape are equal. This is explained by the fact that steam is supplied to the steam cooking chamber, the temperature of which is higher than the boiling point of water. Consequently, when cooking products in a steam atmosphere, the average temperature difference between the steam and the product is higher than the average temperature difference between boiling water and the product. This leads to an increase in the heat flow supplied per unit time per unit surface of the product, compared to the heat flow supplied by boiling water. The speed of preparation of the product is greatly influenced by its shape. The greater the ratio of the surface of the product to its volume, the faster, with other equal conditions, the product is being prepared. For example, carrots cut into 8 mm cubes will be cooked 5 times faster than carrots cut into 8x8x50 mm sticks with the same distance from the surface to the center in the first and second cases.

Classification of cooking equipment.

Food boilers are designed for cooking broths, soups, cereals and other dishes in catering establishments. All digester boilers are classified as follows:

By type of energy used They are divided into solid fuel, electric, gas and steam.

According to the method of heating the working chamber They are divided into boilers with direct (solid fuel, gas) and indirect heating, where distilled water is used as an intermediate coolant.

By method installations of digester boilers are classified into non-tipping, tilting and with a removable cooking vessel,

According to the geometric dimensions of the cooking vessel digester boilers are classified into non-modulated, sectional modulated and boilers for functional containers. Non-modulated digester kettles have a cylindrical cooking vessel. Sectional modulated boilers and boilers for functional containers have a cooking vessel with a rectangular (in plan) cooking container. The cooking vessel of boilers for functional containers has dimensions in plan that correspond to the dimensions of the functional containers.

According to the classification, all digester boilers have alphanumeric indexing. For non-modulating boilers, the letters indicate the group, type of boiler and type of energy carrier, and the numbers following them indicate the capacity of the cooking vessel in dm 3. For example, the boiler index KPE-250 is deciphered as follows: K - boiler; P - digestive; E - electric; 250 - capacity in dm 3.

For sectional modulated ones, the letters SM are added accordingly; all other designations are the same as for non-modulating boilers.

For boilers for functional containers, the index includes the letters: K - boiler; E - electric; the figure shows the capacity of the cooking vessel in dm 3, for example, a KE-100 boiler.

The index of devices with a removable cooking vessel UEV-60 is deciphered as follows: U - device; E - electric; B - cooking; 60 - capacity, dm 3.

Boilers operating under pressure in the working chamber above atmospheric pressure are called autoclaves. Their index, for example, AE-60 stands for: A - autoclave; E - electric; 60 - capacity, dm 3.

Due to the fact that the most widely used heating method is indirectly heated boilers (non-tipping and tilting), we will consider their operation.

2. Food boilers. Schematic diagram.

The boiler (Fig. 22.1) consists of a cooking vessel 6 and a housing - an outer boiler 4, connected to each other by welding. The space between them forms a heating chamber - a steam-water jacket 2. At the bottom of the jacket there is a steam generator 1 , in which water vapor is generated, filling the boiler jacket. The outer boiler is enclosed in thermal insulation 3, which is closed by a casing 5. The top of the boiler is closed with a lid 7.

Indirectly heated food boilers are equipped with control and measuring instruments and various types of fittings: double safety valve 9, pressure gauge 10 (for electric tilting boilers - electric contact), filling funnel 11 (not available for steam boilers), level tap 12 (for steam boilers - purge), turbine valve 8 (for There is no boiler with a leaking lid, fig. 22.2).

To protect operating personnel from accidents associated with the operation of boilers, such protective equipment is provided as double safety valve(Fig. 22.3), installed on a reinforcement stand. The valve is called double because it provides double protection: it protects the boiler from explosion when the steam pressure in the steam-water jacket increases above the permissible norm and prevents deformation when the pressure in the jacket drops below atmospheric pressure.

Operating principle. The water in the steam generator is heated by heating elements to a boil, the resulting steam enters the steam-water jacket and, in contact with the walls and bottom of the boiler, condenses, releasing the heat of steam formation, due to which its contents are heated. The condensate flows down the walls back into the steam generator and turns into steam again.

Indirectly heated fire boilers work similarly. The water in the steam generators of these boilers is heated through the wall of the external boiler.

3. Non-tipping boilers. Design, principle of operation

Non-tipping boilers include boilers with a cooking vessel capacity of 100 dm 3 or more.

In catering establishments they are used with different ways heating: electric - KPE-100-1M, KPE-160-1M, KPE-250-1M; with steam heating - KPP-100-1M, KPP-160-1M, KPP-250-1M; with electrical heating for functional containers - KE-160M, KE-250M; with gas heating, sectional modulated - KPSGM-250; solid fuel - KPT-160.

Electric boilers of the KPE type. Boilers of this type (KPE-100-1M, KPE-160-Sh and KPE-250-1M) have the same design, but differ in the volume of the cooking vessel, the power of the heating elements installed in the steam generators, and dimensions. All of them refer to stationary non-tipping boilers with a leaky lid.

Boiler design KPE-100-1M(Fig. 22.4) . The boiler consists of a cooking vessel 8, connected to an external boiler 21 welding The space between the cooking vessel and the outer boiler is a steam-water jacket 22. A steam generator is located in its lower part 2 with heating elements 1 (Fig. 22.5) and a level 3 sensor, made in the form of a thermal cylinder.

Water (distilled or boiled) is poured into the steam generator through funnel 5 until it begins to flow out of the test tap 11. To maintain steam pressure in the steam-water jacket V within the range from 0.005 to 0.035 MPa, a pressure switch is used 15. and for visual control of pressure - pressure gauge 6. To relieve pressure above 0.05 MPa, safety valve 7 is used. The boiler cooking vessel is closed with a leak-proof lid 4. The lid is lowered and raised using an external counterweight 14. The angle of installation of the cover can be selected within the range of 30-90°. To drain the water, there is a drain valve 17. Inside the brewing vessel, the hole to the drain valve is closed with a removable filter 20. There is a filling tap for filling the brewing vessel 23.

Between the outer boiler and the cladding 19 there is thermal insulation 18 in the form of sheets of aluminum foil. The boiler casing is made of sheet steel and painted with light enamel. The main part of the electrical switching, signaling and automatic control devices is located in the form of a control station on the wall near the boiler.

The boiler is equipped with control and measuring equipment (Fig. 22.6).

In Fig. 22.7 presents equipment for automatic regulation boiler operation.

In Fig. 22.8 shows the folding clamp of the boiler lid and the air valve.

Having installed the boiler, hot and cold water supply pipelines are supplied and connected to it, as well as a pipeline for discharging boiling vapors into the sewer system according to the diagram shown in Fig. 22.9.

Before turning on the boiler, the valve on the boiling vapor removal pipeline must be open, the black arrow of the pressure gauge must be at zero, the control arrow of the upper pressure limit is set to a pressure of 0.4, and the control arrow of the lower pressure limit is set to 0.15.

The control arrows are installed using a special key (as shown by the red arrow in Fig. 20.11).

To turn on the boiler, you need to press one of the “start” buttons (on the boiler or at the control station), this will turn on all six electric heaters of the boiler and both signal lamps on the control station will light up. As soon as steam appears from the air valve, the valve must be closed.

When the pressure in the steam-water jacket reaches the upper limit, 7 out of 8 electric heaters are automatically turned off. In this case, one of the signal lamps goes out.

To stop the boiler after finishing cooking, just press the “stop” button and make sure that both warning lights go out.

Before opening the boiler lid, you should carefully lift the turbine valve by the ring and release excess steam to avoid the risk of burns. The folding clamps securing the boiler lid are released one by one, turning each half a turn. After unloading the boiler from food, it is thoroughly washed hot water, which is then removed through the drain valve.

Every day, upon completion of work, the turbine valve and steam outlet pipe should also be washed with hot water. The boiler lining is wiped with a soft cloth. The proper grounding of the boiler body and control station must be regularly checked by specialists.

Operating principle. The boiler operates in three modes: 1 - “Cooking”, 2 - “Warming up”, 3 - “Steaming”. First mode("Cooking"). The boiler turns on at full power of the heating elements. The boiler is turned on by the green “On” lamp at the control station. The automatic shutdown of the boiler due to the activation of the “dry running” protection is indicated by the red “No water” lamp. After turning on the boiler and the green “On” lamp lights up, the pressure in the steam-water jacket increases. The resulting steam rises up and displaces the air, which exits through the forcibly open safety valve 7. The safety valve handle is turned with the arrow up. As soon as the temperature of the contents of the digester reaches 80-85 ° C, steam begins to escape through the open safety valve. In this case, you need to turn the safety valve handle with the arrow down and stop the steam coming out. The steam pressure in the steam-water jacket will begin to increase and after some time will reach the upper specified limit (0.035 MPa), and the temperature inside the cooking vessel will be approximately 95°C. In this case, the pressure switch will switch the boiler to 1/8 heating element power and maintain a quiet boiling mode. If the steam pressure in the steam-water jacket drops and reaches the lower limit of 0.005 MPa, the pressure switch will again switch the heating elements to full power.

Second mode(“Warming up”). The boiler turns on at full power. When the pressure in the steam-water jacket reaches the upper limit (0.035 MPa), the contents of the cooking vessel boil, and the pressure switch turns off the heating elements.

Third mode(“Steaming”). The boiler turns on at full power, and when the steam pressure in the steam-water jacket reaches the upper specified limit (0.035 MPa), the water in the cooking vessel boils, and the pressure switch switches the heating elements to 1/8 power. If the pressure continues to fall and reaches the lower set limit, the pressure switch switches the heating elements to 1/2 power. When the upper specified limit is reached, the pressure switch again switches the heating elements to 1/8 power and so the cycle will be repeated until the boiler turns off.

4. Steam digester boilers CPP

Steam digester boilers KPP. This type of boiler is advisable to use in a public catering establishment, which is located on the territory of a plant that has its own boiler room that produces Steam for technological purposes. Boilers KPP-100-1M, KPP-160-1M and KPP-250-1M are unified with electric boilers of the same capacity. Since all KPP-type boilers have the same design and differ from each other only in the capacity of the cooking vessel, dimensions and weight, we will consider the design and principle of their operation using the example of the KPP-100-1M boiler.

Boiler design. The boiler is a prefabricated welded structure, consisting of a cooking vessel hermetically connected to the outer casing. The resulting closed space between the inner and outer casing serves as a steam jacket. Thermal insulation, made of corrugated aluminum foil, is placed between the outer casing of the boiler and the lining. The upper cooking vessel with a steam-water jacket is installed on a base, the flange of which has holes for attaching the boiler to the foundation. A condensate trap with pipelines is located inside the cylindrical base. It is designed in such a way that it does not allow the passage of uncondensed steam, but only condensate. Steam enters the steam jacket through a valve. A test valve is used to remove air and condensate from the steam jacket before starting the boiler. The steam pressure in the jacket is controlled by a pressure and vacuum gauge. When the pressure in the jacket increases above 0.05 MPa, the safety valve is activated. Water is supplied to the cooking vessel through a tube. The cooking vessel is closed with a lid connected to a spring counterweight. To drain the liquid, use a drain valve, the inlet of which is closed with a mesh.

Operating principle. The amount of steam supplied from the main line into the steam jacket is regulated by a valve. The air is displaced by steam and exits through the initially open tap, and after closing it through the safety valve. To do this, its handle must be turned with the arrow pointing upward. After a steady stream of steam appears from the safety valve, its handle is turned with the arrow down and the valve closes. Pressure begins to increase in the steam jacket. By turning the valve, you can reduce the pressure increase. Pressure control is carried out according to the pressure and vacuum gauge readings. If there is no pressure control, then when the pressure reaches 0.045 MPa, the safety valve is activated and relieves the pressure. The quiet boiling mode is regulated by supplying steam to the steam jacket.

5. Electric digester boilers for functional containers (FE)

Boilers KE-100M, KE-160M ​​and KE-250M are designed for preparing side dishes, cereals, first courses, sauces, compotes and other dishes in catering establishments. The main feature of the operation of these boilers is that the cooking of products in such boilers can be carried out in functional containers placed in a cassette. The operating principle of these boilers is as follows: the product to be cooked is placed in functional containers and installed in a cassette along the guide corners. Then, using the lifting mechanism of the trolley, the cassette is lowered into the cooking vessel of the boiler.

Let us consider the design of boilers of this type using the example of the KE-250M boiler.

Boiler design. The boiler is a welded structure. Cooking vessel hermetically connected to the shell , to which the steam generator is welded . A steam-water jacket is located between the cooking vessel and the shell. Between the shell and facing sheets there is thermal insulation made of sheets of corrugated aluminum foil. Inside the steam generator heating elements are located . To protect heating elements from “dry running”, a temperature sensor-relay is used, the temperature-sensitive cylinder of which is fixed to the uppermost heating element. A decrease in the water level in the steam generator below the level of the upper heating element triggers the “dry running” protection and turns off the heating elements. Water is poured into the steam generator through a funnel , level controlled by tap . The steam pressure in the steam-water jacket is maintained at a certain range (0.0045-0.045 MPa) using a pressure switch sensor . When the steam pressure in the steam-water jacket is above 0.05 MPa, the safety valve is activated. Filling the cooking vessel with water is carried out by opening the tap . Liquid is drained from the cooking vessel through the drain valve , the opening of which is protected by a mesh (filter). To prevent burns to operating personnel when lifting the lid when the contents are boiling, steam is removed to the outside through a bypass valve. WITH inside the valve cover has a reflector . The tight fit of the lid is ensured by hinged levers . The boiler control and alarm elements are displayed on the control panel.

Operating principle. The boiler has three operating modes: 1 - “Cooking”, 2 - “Warming up”, 3 - “Steaming”. Boiler operating modes are set manually using a switch 21. The numbers 1, 2, 3 on the switch correspond to the names of the modes.

First mode("Cooking"). If the first mode is set, the heating elements are turned on at full power, the switch is in position 1. The water in the steam generator is heated to a boil and steam displaces air through the safety valve. The valve handle should be turned with the arrow pointing up. When a steady stream of steam appears from the opening of the safety valve, the handle is turned with the arrow pointing down and the valve closes. When the pressure in the steam-water jacket reaches the upper specified limit (0.035 MPa), the pressure switch switches the heating elements to 1/6 power. If the pressure in the steam-water jacket continues to fall and reaches the lower limit (0.005 MPa), the pressure sensor-switch will switch the heating elements to full power.

Second mode(“Warming up”). The switch is set to position 2, and the heating elements are turned on at full power. When the upper value of steam pressure in the steam-water jacket is reached, the pressure sensor-relay turns off the heating elements. To turn it on again, you need to change the position of the switch.

Third mode(“Steaming”). The switch is set to position 3. In this case, the heating elements are turned on at full power, and when the upper specified pressure limit is reached, the pressure sensor switch switches the heating elements to 1/6 power. The pressure in the jacket will decrease accordingly and, when the lower specified limit is reached, the sensor-relay will switch the heating elements to 1/2 power, and upon reaching the upper specified pressure limit, it will again switch to 1/6 the power of the heating elements, and the cycle will repeat.

All KE type boilers are equipped with devices for automatic transfer of liquid from the cooking vessel into functional containers, mobile boilers, and food warmers. When pouring, the boiler lid remains tightly closed and pressed with hinged levers. Draining is carried out through the drain valve due to the fact that when the Liquid boils, excess steam pressure is created in the cooking vessel, which displaces the liquid from the cooking vessel.

The KE-100M and KE-160M ​​boilers differ from the considered KE-250M boiler in the capacity of the cooking vessels, the power of the heating elements, dimensions and weight. In terms of operating efficiency, the boilers have approximately equal indicators, but the best is still the KE-250M boiler. Its efficiency when heating from 20 to 95°C is 79.3%, while for the other two it is approximately the same and amounts to 75%.

6. Tilting boilers

Electric sectional modular boiler KPESM-60M(Fig. 22.12) is a cooking vessel 1 of of stainless steel, suspended on pedestals 8 and 11. WITH outside a shell is welded to the boiler, to which a removable bottom is hermetically attached. Three heating elements and an electrode for protecting the heating elements from “dry running” are mounted in the bottom. The closed space between the shell with the bottom and the cooking vessel is filled with water and steam and serves as a steam-water jacket. The latter is connected by a pipe to a unit of control and measuring instruments: an electric contact pressure gauge 4, double safety valve 6 and filling funnel 5. The boiler is equipped with a level tap 9. The cooking vessel is fixed in a casing and equipped with thermal insulation. The top of the cooking vessel is closed with a lid 3 with a device 2 for lifting it and a friction clutch that fixes the lid in any position. The cabinets are a welded frame mounted on four height-adjustable legs 10 and covered with cladding. The cabinets are equipped with cast iron brackets with sliding bearings, on which the boiler rests using hollow pins. The top of the cabinets is covered with a stainless steel table.

The boiler has a rotating mechanism located in the right cabinet and representing a worm pair. The worm wheel is mounted by means of a key on a pin connected to the boiler body. A worm is engaged with the worm wheel, at the protruding end of which a handwheel with handle 7 is attached.

Dry running protection prevents the boiler from turning on if the heating elements are not completely covered with water; The boiler is disconnected from the power supply even if the water level drops to a certain limit and if the boiler overturns. If the water level in the steam generator is insufficient, the warning lamp lights up 14.

Water is supplied to the boiler from the water supply column using a rotary tap.

The left cabinet contains a panel with electrical equipment. On front side displayed: signal lights "On" 13 and "No water" 14 and switch 12 to set the boiler operating mode.

Principle of operation. The boiler operates in two modes. In the first mode, the boiler works first at full power, and after increasing the pressure in the jacket to the specified upper limit, it switches to low heat(1/9 power). After the pressure drops to the lower set limit, the boiler turns on again at full power. This operating mode is used when cooking soups, borscht and other first courses. In the second mode, the boiler operates at full power until the pressure in the jacket reaches the upper specified limit. After this, the boiler heaters are completely switched off. Products are cooked using accumulated heat without consuming electricity. The second mode is used when boiling milk, cooking jelly, vegetables.

Electric boilers KPE-60(Fig. 22.13) are installed on a cast iron fork-shaped frame 10 using two hollow pins 8 and 16 connected to the outer boiler 15. Swivel mechanism 9 has the same device as the KPESM-60M boiler. To fill the brewing vessel 1 with water, a water pipe 17, equipped with a valve 18, water outlet 20 and bracket 19 for hanging the lid. The digester with the fairing 2 installed on it from the outside is closed with an easily removable lid 3. The lid has a handle in the center and steel hook on the inside, with the help of which it is hung on the bracket. The boiler fittings include a 7 electrical contact pressure gauge mounted on the fitting stand. 4, double safety valve 6, filling funnel 5 and level tap 11. Steam is generated at the bottom of the jacket using three heating elements 13 (Fig. 20.17), mounted on a removable bottom 14 boiler The boiler is equipped with a grounding bolt 12.

The boilers have two operating modes and are equipped with automatic regulation of thermal conditions and automatic protection of heating elements from dry running. Protection is carried out using an electrode mounted in a removable bottom 14 boiler

In Fig. 22.14 shows the frame and rotation mechanism of the KPE-60 electric boiler.

In Fig. 20.15 shows the control and measuring instruments of the KPE-60 electric boiler.

In Fig. Figure 22.16 shows a diagram for switching heating elements of the KPE-60 electric boiler.

7. Rules for operating digester boilers

Before starting cooking, check the sanitary condition of the boiler and press the safety valve lever (for tilting and non-tipping boilers old design). For boilers KPE-100-1, KPE-160-1, KPE-250-1 and for steam boilers, it is necessary to turn the safety valve handle so that the arrow points upward. This is done in order to prevent the valves from sticking to the seat and to open the valve to remove air from the boiler jacket. The air is removed through the special air valve of the safety valve or through the safety valve (new boilers) or through the filling funnel if the safety valve does not have an air valve. Air from the jacket must be removed, since its presence in the jacket impairs heat transfer from the steam-water mixture to the boiler wall, which leads to a significant increase in its heating time and excessive energy consumption. Then check the presence of water in the steam generator. If water does not flow out of the open level tap, it is poured through the filling funnel. In this case, the funnel valve, level control valve or test drain valve must be open. As soon as water appears from the level valve or fractional drain valve, they are closed and the filling of the jacket is stopped. To prevent scale formation on heating elements and other heat transfer surfaces, cooled water must be poured into the steam generator. boiled water(the presence of scale in the case of using hard water impairs heat transfer and accelerates the failure of heating elements). After this, the turbine valve (if equipped) is washed.

A filter mesh is installed on the drain valve opening of a non-tipping boiler to protect the drain valve from clogging with product particles. When cooking first courses, the digester is filled with food and water to a level 10-12 cm below the upper edge of the boiler. The lid of the boiler is closed, after first checking the condition of the rubber gasket. The clamping bolts of the sealed cover are screwed in two steps to prevent it from skewing and breaking the bolt threads. When opening the lid, the bolts are also unscrewed in two steps.

Next, check the position of the arrows of the electric contact pressure gauge, which for tilting boilers should be set to the upper - 0.035 MPa and lower 005 MPa pressure limits. If this is not done, the arrows must be installed with a special key. When installing the arrows, the key is inserted into the hole in the center of the pressure gauge and the lever equipped with a stop is pressed. Using this lever, the arrows are moved and set to the required position. Then the boiler operating mode is set using a switch and checked by turning on the signal lamp. In the first mode of operation of the boiler, all the heating elements work first, and after its contents boil and the pressure in the jacket reaches the upper specified limit, the heating elements switch to 1/9 power; The cooking process begins. In the second operating mode of the boiler, all the heating elements are also turned on at first, and after it warms up, the boiler is automatically disconnected from the power supply, and the products are finished cooking using the heat accumulated by the boiler.

The beginning of boiling of the contents of the boiler is recognized by the rotation of the turbine valve ring (for boilers with a sealed lid). During operation, boiling vapors are discharged from the boiler into the room through a turbine valve. During operation, use a pressure gauge to monitor the steam pressure in the jacket. If the pressure rises above 0.04 MPa, the boiler is turned off.

During the work process, it becomes necessary to add products and check their readiness. To do this, first of all press the “Stop” button and disconnect the boiler from the power supply. Then wooden stick lift the turbine valve by the ring, release excess steam from under the boiler lid, unscrew the bolts, first loosening them and then unscrewing them completely, and open the lid, being careful not to get burned by the steam. Having added the products, close the lid again in the above sequence and turn on the boiler by pressing the “Start” button. You can add products to boilers with an unsealed closed lid without disconnecting the boilers from the network.

5-10 minutes before the end of cooking, turn off the boiler (Fig. 20.18), then, carefully opening the lid, unload and rinse warm water with the addition of soda. The turbine valve and steam outlet pipe in old KPZ-100 boilers are washed daily, for which the valve labeled “Rinsing” is opened. The steam outlet is washed with the lid closed; The water is drained through the drain valve. The boiler is left open to dry. From the outside it is wiped with a soft damp cloth.

8. Food boilers from Metos and Falcon

Among the foreign digester boilers, boilers from the company "FALCON" (Great Britain) and the company "Matos" (Finland) should be highlighted.

Electric boilers from "FALCON" Available in two types: classic round series E-3078 and rectangular series E-3080. Each series, in turn, is divided into direct heating boilers (heating elements are located under the bottom of the boiler) and so-called dual-use boilers. In "dual-purpose" boilers, in the first case the cooking vessel can be used as a direct heating boiler; in the second case, a smaller container (liner) can be inserted into it. After placing the liner in the boiler, water is poured into it and after boiling, it acts as a steam-water jacket, heating the liner with the product. The heating of the boiler is controlled by a power regulator, which allows you to effectively change the temperature of the water in the boiler from low to vigorous boiling.

The boilers have the appropriate designation: the last two digits indicate the capacity of the digester in dm 3; boilers with liners are coded using a fraction, where the numerator is the capacity of the boiler, the denominator is the capacity of the liner.

Electric food boilers from "Matos" are produced under the name "Wiking" models 4C, 6C, 8C, 12 with a capacity of 40, 60, 80 and 120 liters with intermediate coolant, respectively. The steam generator is located at the bottom, the space between the inner and outer boiler forms a steam-water jacket. The boiler has fairly effective thermal insulation, consisting of three shells, protection against “dry running”, as well as protection that turns off the heating elements when the boiler is tilted. Internal and external boilers are made of stainless steel. On the right support stand of the boiler there is a stepless power regulator with a signal lamp, a cold and hot water and the boiler tilt flywheel. The boiler is equipped with a double safety valve against high pressure in a steam-water jacket and a vacuum valve. The steam pressure in the steam-water jacket is monitored according to the readings of the pressure gauge.

9. Modern digesters

MBM (ITALY). A food boiler is indispensable for preparing dishes in catering establishments. The boiler is made of stainless steel 18/10. It is equipped with a built-in thermostat; the switches are made of heat-resistant plastic (Fig. 22.19).

GIGA (ITALY). Cooking kettle CPEI (Fig. 22.20). Designed for preparing 1 course at catering establishments. Water supply and drainage is carried out using a tap connected to the water supply.

PROMMASH (RUSSIA)

Cooking boilers (Fig. 22.21) with electric and steam heating or electric heating, indispensable for instant cooking first, second and third courses in canteens, cafes, restaurants. It is characterized by simplicity and ease of maintenance. Thanks to a well-thought-out design and the use of the most efficient modern electric heating elements, excellent distribution of operating heat is achieved. The heating temperature regulator and the valve for filling the container with water are located on the front panel. A pressure gauge located on the surface shows the pressure in the water jacket. By design The boilers are stationary, non-tipping, equipped with safety valves in the steam jacket, which are activated when the pressure rises. Nominal volume - 60 l, 100 l. Fixed time service - 10 years. All products are height adjustable.

Tables 22.1 and 22.2 present the technical characteristics of digester boilers.

Table 22.1

Specifications digester boilers E100 and CPEI

Table 22.2

Technical characteristics of KPE digester boilers

Widely used in catering establishments, professional kitchens and food enterprises.

They belong to thermal equipment and are classified:

• by type of coolant - gas, electric and steam;
• by type of heating - cooking boilers with indirect and direct heating;
• according to the method of extracting the prepared product - tilting and stationary digester boilers;
• by type of lid - with sealed and non-sealed;
• by the number and volume of cooking vessels - one or two vessels can have a capacity from 20 to 300 liters or more.

Purpose of cooking boilers

The structure of the digester boiler

Gas and electric digester boilers can be directly or indirectly heated. Equipment with direct heating is less often used in food processing plants and catering establishments, since it is quite difficult to create a uniform temperature over the entire surface of the cooking vessel, which is why its contents burn. In units with indirect heating, the container itself and the products contained in it are heated evenly, which is due to the steam-water jacket located between the double walls of the equipment. The dish does not burn and cooks much faster.

The electric cooking boiler is equipped with automatic devices, designed to regulate the cooking temperature and to protect equipment from turning on heating elements (heating elements) in case of failure large quantity water in the steam generator. Based on the type of coolant, a steam digester boiler is distinguished, which operates from steam generated in the boiler room by an external steam generator.

Stationary and tilting digester boilers

• Tilting digester boilers - the product is unloaded through the top of the cooking vessel when the unit is tilted using mechanical or electromechanical devices. When tilted, the heating elements in such equipment are turned off. Tilting models have a special mount on one or two legs;
• stationary cooking boilers - models equipped with stationary cooking containers in which finished food, liquid or semi-finished products are discharged through a tap with a large diameter.

According to the type of closure, digester boilers are:

• with non-sealed lids - the cooking process takes place under atmospheric pressure;
• with airtight lids - food is cooked under high blood pressure. In such devices, dishes are prepared much faster, and food is less boiled.

The price for a cooking boiler depends on the type of equipment, heating method, the presence of additional devices, the number and volume of cooking vessels, and some other characteristics. Big choice units allows you to select the required model to suit your needs and tasks public institution or food enterprise.

Food boilers belong to the category of thermal technological equipment and are intended for boiling water and boiling food. Simply put, these devices are used for cooking food in large quantities. What is special about digester boilers and how do they work? More on this later in our article.

Differences from traditional gas stoves

It is worth noting that this technological equipment The design is not at all similar to the modern ovens and stoves that we are used to seeing in the kitchen. The main feature of digester boilers is the scale of cooking. Conventional home stoves cannot cook food so quickly, and besides, when using such equipment, control over the entire process can easily be exercised by one person. Thus, the digester boiler significantly saves time and minimizes human resources. Of course, the size of such devices is several times larger than the dimensions of a conventional stove, so it is simply impractical to use them for domestic purposes, and there is no point in turning it on for 2-3 liters of food (this is 1/100 of everything that it should process).

Application

Often such instruments can be seen in canteens industrial enterprises with more than 100 employees. In such containers, first and second courses are quickly prepared, vegetables are boiled for salads, as well as semi-finished products are prepared. In addition, food kettles do an excellent job with side dishes, sauces, hot drinks and even sweet dishes.

Operating modes

This tool can operate in several operating modes. This includes cooking food, reheating it and steaming it.

Varieties

At the moment, there are several types of these devices, namely:

• Tilting and non-tipping digester boilers.
• Stationary and mobile.
• By type of heater - electric, steam, gas and fire.

Naturally, the most versatile equipment is a mobile boiler with a tilting container. However, the cost of such a device is hundreds of thousands of rubles.

It is worth noting that, despite the widespread gas stoves, electric drives are most often used on digester boilers. Why? The point is that, thanks to this method heating, you can adjust the temperature of the container in several ranges. Gas instruments have either two degree modes or do not have them at all, that is, how much the side dish or water heats up, this will be its temperature.

Work algorithm

As for the principle of operation, the digester boiler (including KPEM 250) works as follows. When heating the coolant (the so-called heating element - it is located in the “jacket” of the device), heat is generated between the walls of the vessel, which are most often filled with air or water. So - with increasing temperature on the walls of the boiler container, the heating of the liquid itself, semi-finished products and other food increases. As you can see, the operating principle of this device is not that complicated.