The main criterion of quality is the product sales temperature, changing within 60 ... 85 ° C. Under these temperatures, the main biochemical processes associated with heating continue and while maintaining products, as a result of which changes occur, causing additional mass losses, the destruction of vitamins and deterioration of organoleptic indicators.
So that these changes are minimal, it is necessary to fulfill the following basic requirements:
The storage and implementation temperature must have the smallest of permissible levels;
The shelf life and implementation should not exceed the permissible and be reduced if possible.
Classification of hot food storage equipment
According to the functional purpose, they are divided into three groups:
Food storage devices in hot condition;
Apparatuses for the sale of food;
The devices that combine the above functions and capable of transporting hot food from the storage location or cooking in the implementation zone.
Also, products can be stored in devices intended for thermal processing: digestive boilers, steam chambers, etc. To do this, use the lower levels of thermal power. However, from an energy point of view, it is ineffective and economically inappropriate.
Marmits.
These are thermal devices designed for short-term storage of food in the hot condition during its implementation or in the process of manufacturing culinary products.
A constructive feature of the marmitis is that culinary products are placed in a pile dishes or in functional containers (gastroestemes), or in special marchs. Produced outdoor and desktop warmets.
The containers used in the marmias (marching) are not thermally insulated and can be separated from the warmer and used not only for the storage of finished products, but also for its preparation.
Marmiths intended for sales are set in the distribution line and are usually sectional modular devices. Such warmarines are divided into marmities for the second and first dishes.
Marmities for second dishes.
Depending on the method of heating, the warmets for the second dishes are divided into water, steam and air ("dry").
Water marches for second dishes.
In water marches, the distribution lines of the distribution of marchs are immersed in the bath with hot water. The bath is located under the working surface of the MARMIT table. Water heating in the bath is carried out either by water tanks located inside the bath or air tanks fixed on the outside of the bath wall. Thermal insulation is usually absent, and its role performs an air layer between the heating bath and the front panels. The temperature of heating water in the bath is supported by the thermostat. The temperature sensor is most often placed directly in water. Accurate support optimal temperature Storage guarantees high quality food.
disadvantages: A large mass of heating water leads to an increase in the duration of heating and, accordingly, increased consumption of the energy carrier. In the process of selling products, Marmintians become easier and can pop up, which leads to a change in the water level in the heating bath. Heating marching with varying degrees of filling may be unequal.
Steam marines for second dishes.
For heating marchs in the lower part of the heating bath is located the steam generator. In this case, the heating of marminitz is the same with different filling them. The warmer is quickly heated and does not require a lot of energy consumption.
Disadvantages. When stored, there is a danger of overheating of culinary products and deterioration of its quality, since the temperature of the steam close to 100 ° C is not regulated.
Air marines for second dishes.
Their design differs little from steam counterparts. To heat the air in the heating bath, air centers are used. They are placed either from the outside of the bath and pressed to its walls with brackets, or directly in the bath under march. To control the temperature, a thermostat is used with a regulation range up to 100 ° C. Such warmeters are quickly heated and go to the working mode, convenient to operate.
Marmities for first dishes
They can be attributed to specialized "marminy" plates. These are apparatus in which the length of the heating of food is used electrical or gas burners. Unlike plates in the marchs for the first courses, drinkers with reduced power, round or rectangular with a cast-iron case with a capacity of up to 2 kW are used. They are included in the network through packet power switches.
Thermal showcases.
Thermal showcases are closed chambers with shelves for laid out portioned products. Camera walls are transparent: glass or plexiglass. Heating is carried out either by air tanks or fan heater. In the amount with the help of the thermostat, the temperature is maintained to store the temperature in the range of 40 ... 70 ° C.
Heat racks.
Unlike showcases have open heating surfaces. The dishes are heated by the heated surfaces of the production table or shelves, which are included in the design of the apparatus.
Heating surfaces are solid or local (conforing) and have operating temperatures within 60 ... 85 ° C.
In thermal racks with a solid heating surface in electrical design, air tags attached to the heating wall are used for heating. In the devices with local heating, cast-iron burners with reduced power are most often used.
The design of thermal racks are known in which a boxed flow heat exchanger is used as a heater, inside which the intermediate coolant circulates.
Ok - heaters.
Externally similar to desktop lamp Lighting. Thermal block includes IR generators and reflector. As sources of IR - energy most often serve quartz emitters or emitting tagnes. IR - heaters are produced as separate desktop devices or included in the design of heat racks, located above the working surface of the table or shelves.
Heat cabinets.
Thermal cabinets are a simplified version of the frying cabinets. The main element of the design is the box working chamber, at the bottom of which the heating elements are placed. Unlike the frying cabinets, they are deprived of the upper group of Tan and have a thermostat with a regulation of 30 ... 100 ° C.
Heating air in the working chamber is heated due to natural air convection.
Thermal cabinets can be built into the main technological devices (hot wardrobe, stove or thermal rack), sometimes completely deprived of heating.
The most effective are thermal cabinets with forced air circulation, which are designed to preserve culinary products under the condition of the forced movement of heating air and controlled moisturizing. In the box, the heat insulated working chamber of these cabinets on the bench is stirred by the food product. For the "mixing" of air in the chamber installed the impeller of the centrifugal fan. Such cabinets of the Winteston series were the first to offer the Finnish company Metos.
Optimal values Humidity and air temperature exclude the drying of the product, retain the original structure and the original composition, therefore, organoleptic properties with long-term storage.
Thermostats.
Thermostats are intended for long-term conservation and transportation of first dishes and hot drinks at a constant temperature.
Them distinctive feature The fact that the working chamber is a permanent and fully insulated part of the entire device. Directly in this chamber houses food for storage.
The main part of the thermostat is a cylindrical or box working chamber, tightly closed on top of the lid. To seal the cover, a gasket from heat-resistant food rubber is used, and for its pressed, special mechanical devices, more often screw or cam.
Depending on the capacity and method of transporting the thermostats are divided into portable, mobile and stationary.
Portable Thermostats are designed not only for storing and transporting hot food inside the enterprise, but also for transporting it in transport.
Mobile Thermostats are used for intracourcing displacements.
Stationary Thermostats are usually installed in the line of configuration and sales of finished products.
The specifics of public catering enterprises lies not only in the use of modern technology and production technology, software and in its implementation in a short time on the relevant cultural and aesthetic level with a variety of auxiliary thermal and refrigeration equipment, as well as automated vacation tools for individual types of culinary products.
Equipment for food, combines a group of heat devices designed to perform various operations that are not related to the process of thermal processing of products. It is believed to: thermal racks used for short-term snatching in the hot condition of dishes and heating plates; Thermostats used for storage in hot beverages; Marmities that serve to maintain in the hot state of the first and second dishes, sauces, various cooking products.
For heating and maintaining hot food, various types of gas and electric stoves are used.
The most common electric stove maritating EPM-ZM (Fig.), Used mainly for the service implementation of the first dishes.
Fig. Electric plate circuit Marmite EPM-ZM: A - design; 1 - body; 2 - Introductory shield; 3 - switch; 4 - board; 5 - Konford; B - Scheme of lining of communications
The main working body of the plate is the cast iron burner installed on the reference adjusting screws, which allow combining the plane of the burner with the side surface of the housing. To regulate the power of the stove, the plate is equipped with an input shield and a packet switch. In the first 20 ... 30 min, the slab is included for the maximum power for heating it. After that, the burner is switched to medium or weak heating depending on the desired temperature and the amount of heated product. The power consumption of the plate is 2.5 kW. Electrical safety is ensured by reinforcing and protective disconnection (Fig.).
Fig. Electrical circuit plate EPM-ZM: A - general scheme; E - Konford; S - switch; X - terminal block; B - Scheme of lining of communications
For heating and maintaining in the hot condition of the first dishes in large capacities when they are vacated in the canteen self-service, an electric plate is used for marmitic EPM-5 (Fig.).
Fig. The circuit of the electric stove maritage EPM-5: 1 - frame; 2 - input shield; 3 - switch; 4 - Konford; 5 - table; 6 - shelf; 7 - sleeve for supplying the cable; 8 - Ground Bolt
Electric stove has the type of open fit, at the bottom of which on metallic frame There are three electrical burners installed. The base serves as lined with frames of the frame. At the top of the adhesion on the brackets pinned the shelf for plates. There is also a table.
The burners are turned on and off with batch switches. Each burner is turned on separately on any of the three power steps.
Installation of electrical wiring and electric shock protection system are made in accordance with the rules of the electrical installation device. On the distribution shield Installed starting and protective equipment. Principal electrical circuit Plates of EPM-5, the total power consumption of which is 3.75 kW, is shown in Fig.
Fig. EPM-5 plate electrical circuit diagram: Si, S2, S3 - packet switches; E7, E2, Yez - Electro components; X - Terminal Pad
On specialized catering facilities with a bar (buffet) method of maintenance for heating in on-plate dishes of the first and second dishes apply desktop electric phenk-2 (Fig.).
Fig. Plate Desktop Electric PNEK-2: 1 - Konford; 2 - lifting table; 3 - pallet; 4- switch
The stove has two burners, each of them is equipped with a switch by means of which the drive is turned on and stepped control. The total rated power of the burner is 2.4 kW.
For heating various culinary products, as well as for cooking for a couple of meat, fish and vegetables, a steaming electric APE-1B is used (Fig.).
Fig. Apparatus Steamer electric APE-1B: 1 - Cap; 2 - perforated skeleton; 3 - sector containers; 4 - non-perforated skewers with a lid; 5- working cameras; 6-lattices; 7- cap with level tubes; 8 - steam generator; 9 - Tenny; 10 - terminal panel; 11 - base; 12 - anchor bolt; 13 - drain tube; 14 - ball float; 15 - Nutritional Tank
The main working bodies of the device are the steam generator, the nourishing tank, four retractable cameras.
The steam generator is filled with water from the nutrient tank through the system of the communicating vessel, the constant level of which is supported by a float valve. Three-tan are attached to the bottom of the steam generator. Above the steam generator is a working chamber of the device consisting of four rotary tanks. Under them, a fixed cap, connected to the base with three vertical racks and axis, around which, regardless of another, all rotary capacity of the chamber can rotate. Each swivel container is equipped with a textolite handle with a spring lock, which allows you to fix it in a closed position.
The principle of operation of the device lies in the fact that steam from the steam generator, rising from the bottom up, consistently passes through all the capacitances of the chamber, where, in contact with the heated products, condenses, giving them heat.
To protect the steam generator from overflowing with water in case of failure of the float valve, a level tube is provided in the steam generator, through which the excess water is drained into the sewer.
In fig. A diagram of the lodging of communications to the device with the necessary mounting dimensions is shown.
Fig. Scheme of communication of communications to the heat apparatus of ApE: 1 - supply pipeline cold water; 2 - konta support and exhaust ventilation; 3 - valve; 4 - Route
For heating and maintaining hot conditions of various drinks (coffee, cocoa, milk, etc.) use electrothermostats LSB-6M, ET-20, TE-25. They establish them, as a rule, on the shelves of buffets, cafeteria racks and self-service lines.
In fig. The structural diagram of the LSB-6M electrothermostat is shown.
Fig. Electrotermostat LSB-6M: 1 - tank; 2 - TEN; 3 - body; 4 - crane; 5 - pallet
It is a steel cylindrical tank, turning into a rectangular flange. Beverage heating is carried out by the Tanni installed in its lower part. The thermostat is connected to the power grid through a cord with a plug fitting with a grounding contact. The required temperature of the beverage filled into the electrothermostat is supported by the electron heater toggle switch. The capacity of the tank is 20 liters, the power consumption is 0.4 kW. Drinks are spilled with a stick.
The principle of operation of the electrothermostat ET-20, as well as in LSB-6m. The difference is that heated beverage in it is carried out by a tubular electric heater placed at the bottom of the tank.
Thermostat TE-25 has a removable drawer with a tap. It is heated by analogy with LSB-6M.
Regulation temperature mode The thermostat is performed by a temperature sensor, the leb led to the control panel. The thermostat is equipped with a lamp signaling an electrical heater. The useful capacity of the tank is 25 liters, the power consumption is 0.5 kW.
Heat devices for heat thermostat can be divided according to the functional purpose to three main groups:
- devices intended for storage of food in the hot condition;
- devices intended for the sale of food;
- devices that combine the above functions and capable of transporting hot food from the storage location or cooking in the implementation zone.
The last direction is most promising, since the overload operations are excluded, which not only creates certain organizational amenities, but also reduces the loss of mass and heat, inevitably arising in this case.
It is possible to store ready-made culinary products in principle in the main thermal devices intended for culinary heat treatment: digestive boilers, steam chambers, etc. For this, the lower levels of thermal power are used for this providing the necessary temperatures. Obviously, the use of basic heat apparatuses to store food is economically inexpedient, since the cost of this type of equipment is high.
The most common catering facilities currently in the domestic catering facilities for storing food in the hot condition include: warmeters, thermal racks, thermostats and thermal cabinets.
Marmits. These are thermal devices designed to store food hot during its implementation period on the distribution line. The design feature of the marmitis, distinguishing them from other thermostatic devices, is that food is placed in a punching dish or in functional containers, or in special containers that are part of the Marmmit - marchy, and the warmer itself is usually stationary. Capacities for storage of food are not insulated and can be separated from the marmit and used not only for the storage of finished products, but also for its preparation.
Since the marmities are intended for sale, i.e. Install in the distribution line, they are usually sectional modulated devices. At the same time, the placement zone of marchs is most often the plane corresponding to the surface of the desktop and located at a distance of 800 ... 900 mm from the floor level. In some cases, when there is a thermostatization of a significant volume of a significant volume (20 dm 3 or more), the surface of the compensation heaters to which the containers are installed, is located on the floor level at a distance of 20 ... 30 cm, which reduces the physical costs of lifting tanks and improves Terms of work of the service personnel.
Desktop scheme Usually used in marmiths intended for thermostatization of the first courses and sides (potato, cereal and pasta). Such a scheme includes a set of marchs for all types of culinary products. In the process of storage, as needed, hot food is retrieved from marchs for configuration of dishes and their implementation. Elemented marchs are replaced with filled.
When heating marminets with water bath by changing the power of the Tan (or the consumption of steam in the tubular steamer), the temperature of heating water is reached from 70 to 90 ° C. Water vaporization is practically absent. When using a steam bath, a warming pair has a temperature equal to boiling point.
Marmiths with a water bath, despite the possibility of regulating the temperature of the brass medium, due to the considerable mass and high thermal inertia are inferior in efficiency with steam heating; For this reason, the latter are in practice significantly wider use.
The design of warmets with air heating marminets is similar to the design of the marches with a water bath, but in heating volume instead of water is located hot air; Heating volume in this case is significantly reduced.
The marmines with an outdoor arrangement of the heating surface most often are an electric stove with burners, heating the bottom of the pincible dishes, in which heat metering occurs.
Heat racks. These are devices designed to heal dishes (plates, cups, glasses) and placed in it portioned and prepared for the implementation of dishes.
It is used as the main thermal elements heated to temperatures 60 ... 90 ° C horizontal surfaces (shelves). Electric thermal racks, electric heaters are used as a heater closed typeworking in the mode of small specific thermal loads (W< 2 Вт/см 2).
When using a centralized heat supply scheme of the working surfaces of thermal racks, in addition to electric heating, gas or vapor heating can be used. In this case, the intermediate coolant is heated in the steam generator and the gear pump is pumped through a group of flat heat exchangers. With movement, the temperature of the coolant varies from 85 ... 90 ° C at the entrance to the first group of heat exchangers to 60 ... 70 ° C on the tail areas. These modest characteristics comply with the requirements of heat thermostat and, in turn, are source for determining the power of the device, as well as the power and performance of the gear pump. An intermediate coolant is used or severe mineral (engine) oil, or silicone liquids (polyorganosiloxanes).
Thermostats. Heat devices intended for long-term storage of writing at a constant temperature, called thermostats.
Distinctive constructive feature Thermostats lies in the fact that the working chamber (the amount of thermostatting) is in-section and completely the heat isolated part of the entire device. Directly in this chamber houses food for storage.
The main part of the thermostat is a working chamber cylindrical formor made in the form of parallelepiped. The loading hole of the working chamber is tightly closed with a lid. To compact the connection location, gasket from heat-resistant food rubber is usually used. For pressing the cover, various kinds of mechanical devices are used, more often screw or cam.
Depending on the capacity and the method of transporting the thermostats are divided into mobile, portable and stationary.
Portable are designed not only for storing and transporting hot food inside the enterprise, but also for transporting it in transport. Mobile thermostats are used for intracacure displacements, and stationary are usually installed in the line of configuration and sales of finished products.
Currently, foreign firms produce various thermostats (from simple portable to combined carts) made of heat-resistant plastics and insulated heat insulation. Their practical use is constantly increasing.
Electrical thermostats intended for heating and maintaining coffee, cocoa, milk and other beverages in the process of their implementation are widespread. They set them on the shelves of buffets, cafeteria racks and in self-service lines. Structurally, they are direct heating boilers, in which the TEN is located at the bottom of the cooking vessel.
To ensure mild heating of beverages placed in the electrothermostate, it is advisable to use oil tanes, and not water. In this case, the specific surface power of the TEN tube is reduced from 10 to 6 W / cm 2, which significantly reduces the degree of destruction of beverages, especially when they are repeated heated.
Heat cabinets. Thermal cabinets are a simplified version of the frying and, unlike them, are either deprived of heating elements, or are equipped with low-power heaters. The complete absence of heaters is justified in cases where the heat closet is an auxiliary part of the main apparatus (hot wardrobe, stove or heat rack) and utilizes the heat allocated by this unit. Use heat wardrobes for storage in the hot state of individual components of the portioned dishes. The main element of the heat cabinet design is a box working chamber, at the bottom of which, if necessary, install heating elements. Storable food is placed on special shelves or in special boxes. In the first case, the working chamber has a common door, and in the second boxes are extended independently from each other.
Thermal cabinets of large volumes have, as a rule, the power regulator and thermostat.
Thermostatic devices discussed above work on electric heating. This is due to the fact that the devices most often mounted in the distribution line together with other electrical equipment. The installed power is small and usually does not exceed 5 kW. This power is used only for heating the device, and for the stationary mode there is enough 1/6 ... 1/9 of its part.
When using a steam heat exchanger or gas burner Provide control systems and sewn, determined by the properties of energy carriers and discussed in detail above when studying the main types of thermal equipment for thermal cooking food processing.
When comparing the structures of various thermostatic devices, usually proceed from the following considerations: the lower the specific consumption of heat per unit stored products, the more effective the food storage device in the hot condition. Other an important indicator, indirectly characterizing the degree of perfection of the thermostatic device, the rate of cooling the product with the heaters is disabled, measured in degrees per second (in k / s) or per hour (in k / h). The speed of cooling the product in perfect portable thermostats should not exceed 2 k / h, in mobile thermostats 10, and stationary thermostats, marmiths and thermal cabinets 15 k / h.
In some cases, characterized by a short-term episodic use of a thermostatic device, go to simplify the design with a conscious increase, both the speed of cooling products and specific expenses Energy. This is justified due to the shortness of the entire process and, as a result, due to the low total energy costs.
Processes arising from boiling liquids. Technological aspects of the use and classification of water heating equipment.
Constructions and principle of action of water heaters and boiling holders.
Safety regulations.
Questions for self-test.
157. Bring the DEF-50 filling boiler drawing, explain its device.
158. Bring the CNE Continuous Type Electric Boilet Device Device Scheme, explain the principle of operation.
159. Give the drawing, explain the device, the principle of operation, the technical characteristic of the KNE-25 electric fighters.
160. Give the drawing of the Universal gas boiler-water heater type KNG-200, describe its device and the principle of operation.
161. Draw a scheme, describe the device and rules of operation of solid fuel (fire) boiler type KST-200.
162. Give the drawing of the water heater of the NE-1A and NE-1B type, describe the device and the principle of operation.
163. Give the drawing of the AGB-80 water heater, describe the device and the principle of operation.
Types of universal equipment for thermal processing of food products.
Methods of thermal processing and their differences. Microwave apparatus, classification, design features, principle of operation.
Types of devices for saving food hot. Machines for saving food hot. Classification, design and scope.
Machines for cleaning potatoes and vegetables. The ability to use them in the Potato Processing Lines.
Questions for self-test.
164. Give the classification of devices for thermal processing of products in the microwave field.
165. Give the drawing of the high-frequency microwave cabinet "Electronics", describe its device.
166. Describe the microwave generator device (third-type electric heaters). Bring the design of the magnetron design.
167. Put the drawing and describe the MSESM-3K marmit device.
168. Give the design of the marmates for the second MSESM-60 and MCESM-110 dishes, describe their device.
169. Bring the ITU-84 stationary electric type marming pattern, describe the device and principle of operation.
170. Bring the drawing, describe the purpose and device of the MP-28 mobile type former.
171. Bring the pattern of the heat mobility cabinet Pole-1.5 and describe the device of thermal cabinets of the Step-1, Step-1, pole-1-01.
172. Describe the appointment, the device and the principle of operation of functional containers.
173. Gift the drawing, describe the assignment and device of the distribution type of the CTTES.
174. Describe the appointment and features of the mechanized handouts of self-service, their principle of operation, and also give a drawing of MEP murms.
175. Classification of electric marites for short-term storage of dishes.
176. Describe the appointment, specifications and features of self-service lines.
