RU2615365C2 - Method of fish products hot smoking - Google Patents

Abstract

FIELD: food industry.

SUBSTANCE: method involves the use of steam jet refrigeration machine comprising ejector, evaporator, cold-receiver, recuperative heat exchanger, condenser, expansion valve, condensate collector and steam generator. The cooled and dried air is fed to the preheating into the steam jet refrigeration machine condenser. The resulting steam in a steam generator at a pressure of 0.8 … 1.0 MPa is fed to the ejector nozzle, creating a steam jet in the evaporator refrigerator machine a reduced pressure 0.0009 … 0.001 MPa and a temperature of 4… 7°C. The resulting mixture of refrigerant vapor and operating steam with a pressure of 0.2 … 0.3 MPa is fed to the condenser for the drying agent preheating. Part of condensed water generated in the condenser is supplied into the evaporator for compensation for water expenditure while the rest, together with condensate generated in the process of air cooling in the cold-receiver is discharged first in the condensate collector and the steam generator, thus forming a closed cycle.

EFFECT: end product quality improvement and energy costs reduction.

1 dwg, 2 tbl

Description

The invention relates to methods for smoking products of animal origin and can be used for smoking fish products.

The known method of hot smoking [RF Patent No. 2183065, IPC ⁷ A 23 B 4/044. The method of automatic control of the process of hot smoking of fish products / A.A. Shevtsov, A.N. Ostrikov, Yu.A. Dmitriev / applicant and patent holder Voronezh. state technol. Acad. - Declared. 09/11/2000. Publ. 06/10/2002. Bull. No. 16], which provides for stabilization of heat supply parameters during drying, boiling, smoking and cooling of fish; air supply first for preheating in the condenser of the heat pump installation, and then for drying the fish; cooling the fish with air cooled in the evaporator of the heat pump unit, supplying part of the exhausted cooled air from a closed circuit for mixing with smoke after boiling, with the resulting smoke-air mixture being smoked.

However, in the known method, cooking fish with smoke smoke does not allow to fully ensure uniform moisture and heat treatment throughout the volume of the product; irrational use of smoke made from rare and expensive wood species cannot be considered justified from the point of view of saving material and energy resources. The possibilities of increasing the energy efficiency of the heat pump installation are not realized due to the organization of drying in a closed cycle through the air with its subsequent drying in the working section of the evaporator and heating in the condenser of the heat pump installation.

The closest in technical essence and the achieved effect is the drying method [Pat. No. 2308836 of the Russian Federation, IPC ⁷ A 23 V 4/044. The method of controlling the process of hot smoking of fish / A.N. Ostrikov, A.A. Shevtsov, N.Yu. Chernousova / applicant and patent holder Voronezh. state technol. Acad. - No. 2006112070/13. Stated April 11, 2006. Publ. 10/27/2007. Bull. No. 30], which provides for drying, boiling, smoking and cooling fish; heating the air supplied for drying, first in the condenser of the heat pump unit, and then in the heat exchanger-recuperator; air cooling in a two-section evaporator of a heat pump installation, the working and reserve sections of which alternately operate respectively in condensation and regeneration modes; obtaining saturated steam in a steam generator with electric heating elements and a safety valve with the supply of one part of it to the weld, and the other to regenerate the cooling surface of the backup section of the evaporator; supply of exhaust steam to a heat exchanger-recuperator for heating the air supplied for drying; removal of the condensate formed in the condensate collector and its supply in closed-loop mode again to the steam generator; cooling fish with chilled air in an evaporator of a heat pump unit.

However, the known method has the following disadvantages:

- low quality of finished products;

- low reliability of the steam compression heat pump installation due to the presence of a mechanical drive in it, which can lead to a decrease in the productivity of the drying process for the dried product due to possible stops for maintenance and repair;

- the presence of additional energy costs due to the need for periodic thawing of the "snow coat" formed as a result of condensation of moisture from moist air on the working surface of the evaporator of a steam compression heat pump installation;

- the use of toxic and expensive refrigerants, which makes the method environmentally unsafe;

- the impossibility of using sources of secondary heat of gas turbine units and boiler units, which does not allow to effectively solve energy conservation tasks.

An object of the invention is to improve the quality of finished products, the reliability of the heat pump installation, reduce specific energy consumption and create environmentally friendly technology for smoking fish products.

The object of the invention is achieved by the fact that in the method of hot smoking of fish products, comprising drying, boiling, smoking and cooling the fish, preheating the air supplied to the drying first in the condenser of the heat pump unit, and then in the heat exchanger-recuperator; air cooling in the evaporator of the heat pump installation, obtaining saturated steam in a steam generator with electric heating elements and a safety valve with feeding it to the wire; supply of exhaust steam to a heat exchanger-recuperator for heating the air supplied for drying; removal of the formed condensate into the condensate collector and its supply in a closed cycle mode again to the steam generator, cooling the fish with chilled air in the evaporator of the heat pump installation, the new thing is that when fish products are hot smoked, a steam ejector chiller including an ejector, an evaporator, a cold receiver, an additional heat exchanger is used - recuperator, condenser, thermostatic valve, condensate collector, steam generator operating in a closed thermodynamic cycle in the heat wasp; moreover, the air exhausted after drying is cooled and dried in the cold receiver of the steam ejector chiller by heat transfer from the refrigerant, which is used as water, to the air through the dividing wall of the heat exchange surface, after which the cooled and dried air is fed to the preheater in the condenser of the steam ejector chiller; the working steam obtained in a steam generator with electric heating elements and a safety valve is directed at a pressure of 0.8 ... 1.0 MPa into the ejector nozzle, while creating a reduced pressure of 0.0009 ... 0.001 MPa and a temperature of 4 ... 7 ° C in the evaporator steam ejector chiller due to ejected vapors with recirculation of refrigerant in the cold receiver, the resulting mixture of refrigerant vapor and working steam after the ejector with a pressure of 0.2 ... 0.3 MPa is sent to the condenser to preheat the drying agent, with one part about the water condensate that has developed in the condenser is fed to the evaporator to replenish the loss of water, and the other, together with the condensate formed during cooling of the air in the cold receiver, is diverted first to the condensate collector and then to the steam generator with the formation of a closed cycle; preparation of cold air for cooling fish is carried out in an additional heat exchanger-recuperator installed in the line of ejected vapors.

In FIG. 1 presents a diagram that implements the proposed method.

The circuit contains a drying chamber 1, boil 2, smoking 3 and cooling 4 fish; heat exchanger-recuperator 5; a steam ejector chiller including an ejector 6, an evaporator 7, a cold receiver 8, an additional heat exchanger-recuperator 9, a condenser 10, a thermostatic valve 11, a condensate collector 12, a steam generator 13 with electric heating elements 14 and a safety valve 15; fans 16, 17; pumps 18, 19; lines: 3.1 - feeding fish into the drying chamber 1; 3.2 - feeding fish from the drying chamber 1 to the cooking chamber 2; 3.3 - fish supply from the boil-off chamber 2 to the smoking chamber 3; 3.4 - supply of fish from the smoking chamber 3 to the cooling chamber 4; 3.5 - removal of smoked fish from the cooling chamber 4; 0.1 - air supply from the cold receiver 8 to the condenser 10; 0.2 - air supply from the condenser 10 to the heat exchanger-recuperator 5; 0.3 - air supply from the heat exchanger-recuperator 5 to the fish drying chamber 1; 0.4 - exhaust air from the drying chamber 1 to the cooler 8; 0.5 - recirculation of chilled air through an additional heat exchanger-recuperator 9 and cooling chamber 4; 2.0 - supply of working steam from the steam generator 13 to the ejector 6; 2.1 - removal of ejected vapors from the evaporator 7 to the ejector 6; 2.2 - removal of the mixture of working and ejected vapors from the ejector 6 to the capacitor 10; 2.3 and 2.4 - drainage of condensate from the condenser 10 to the evaporator 7 and the condensate collector 12; 1.0 - recirculation of the refrigerant (water) through the cooler 8 and the evaporator 7; 1.1 - drainage of condensate from the cold receiver 8 to the condensate collector 12; 1.2 - supply of condensate from the condensate collector 12 to the steam generator 13; 2.5 - supply of working steam from the steam generator 13 to the chamber 2; 2.6 - removal of exhaust steam from the chamber of the weld 2 in the heat exchanger-recuperator 5; 2.7 - condensate discharge from the heat exchanger-recuperator 5 to the condensate collector 12; 2.8 - pressure relief in the steam generator 13; 4.0 - supply of smoke in the smoking chamber 3; 4.1 - removal of spent smoke from the smoking chamber 3.

The method is as follows.

In accordance with the specified technology of hot smoking, the fish is subsequently subjected to drying with hot air, saturated steam cooking, smoking with a mixture of smoking smoke and air, cooling with cold air, respectively, in drying chambers 1, welding 2, smoking 3 and cooling 4, into which fish are fed respectively along the lines 3.1, 3.2, 3.3, 3.4, after which the fish is removed through line 3.5 as a finished product.

Air preparation for both drying fish in the drying chamber 1 and cooling it in the cooling chamber 4 is carried out in a steam ejector chiller including an ejector 6, an evaporator 7, a cold receiver 8, an additional heat exchanger-recuperator 9, a condenser 10, a thermostatic valve 11, and a collector condensate 12, a steam generator 13 operating in a heat pump mode.

The mixture of exhaust air after drying with an exhaust fan 16 is taken along line 0.4 to the cooler 8 of the steam ejector chiller and cooled by heat transfer from the refrigerant, which uses water, to air through the heat-exchange surface separating wall. In the cold receiver, the exhaust air reaches the dew point temperature and the moisture contained in it condenses in the form of a droplet liquid on the heat exchange surface, due to which it is drained.

In the steam generator 13 with electric heating elements 14 and a safety valve 15, working steam is formed, one part of which, under pressure of 0.8 ... 1.0 MPa, is sent through line 2.0 to the ejector nozzle 6, thereby creating a reduced pressure of 0.0009 ... 0.001 MPa and temperature 4 ... 7 ° С in the evaporator 7 of the steam ejector chiller. The potential energy of the working steam is converted into the kinetic energy of the jet, which flows out at a high speed, and under the influence of the energy of the jet the refrigerant vapors are ejected through an additional heat exchanger 9 and, via line 2.1, are supplied from the evaporator 7 to the ejector 6.

The resulting mixture of refrigerant vapor and working steam after the ejector with a pressure of 0.2 ... 0.3 MPa is fed through line 2.2 to the condenser 10, where the mixture, condensing by means of regenerative heat exchange, transfers heat to the air, which is heated to a temperature of 65 ... 70 ° C. Using a blowing fan 16, air is fed through line 0.2 to heat exchanger-recuperator 5 and its temperature is brought to 90 ... 110 ° C, and then to drying chamber 1 through line 0.3. One part of the water condensate formed in the condenser 10 is sent via line 2.3 through the thermostatic valve 11 to the evaporator 7 to replenish the loss of water. Another part of it along line 2.4 along with the condensate that was formed during cooling of the air in the cold receiver 8 is taken off through line 1.1 to the condensate collector 12, and then along line 1.2 using pump 18 to the steam generator 13 to form a closed cycle.

The preparation of cold air for cooling the fish is carried out in an additional heat exchanger-recuperator 9 installed in the line of ejected vapors 2.1. In this case, the cooled air recirculates in line 0.5 through the cooling chamber 4 and the heat exchanger-recuperator 9 using the fan 17.

An example implementation of the method.

As a specific example of the implementation of the method, the technology of producing hot smoked fish at the Vostok enterprise (refrigerator of the Voronezh regional consumer union) in a tunnel-type installation for the production of suspended and dried fish products is considered. The limits of regulation of the main technological parameters of the processes of drying, boiling, smoking and cooling of fish are substantiated as a result of experimental studies and are widely represented in the literature.

As the object of hot smoking, frozen Azov-Black Sea mackerel with an initial humidity of 85% was used. The nominal capacity of the installation according to the original mackerel, which has previously undergone technological operations for thawing, sorting, cutting, flavoring and laying on a transporting net, is 200 kg / h.

For the preparation of energy carriers, the tunnel installation is equipped with a steam ejector chiller with the following characteristics:

Cooling capacity, kW ……………………… ..100

Boiling temperature:

in the evaporator, ° С ………………………………………………… 4

in the steam generator, ° С ...................... .............................. 170

Condensation temperature, ° С ………………………. ... ..127

Inlet air temperature

to the condenser, ° С ……………………………… .. …… 10… 12

Outlet air temperature

from the condenser, ° С ………………………………… ..65… 70

Ejection coefficient ……………………………………… .4

Heat transfer coefficient, W / m ² · K ………………… .12

Cooling area

evaporator surface, m ² …………………………… .180

Refrigerant ……………………………………. ………… water

The dried and cooled air in the cold receiver 8 of the steam ejector heat pump unit with a temperature of 7 ± 2 ° C and a moisture content of 0.005 kg / kg is preheated in a condenser 10 to a temperature of 50 ± 2 ° C, and then in a heat exchanger-recuperator 5 to a temperature of 80 ± 2 ° C and at a speed of 1 ± 0.2 m / s is fed into the drying chamber 1.

Temperature regimes for drying fish with air with low moisture content lead to intensive evaporation of surface and osmotically bound moisture and its entrainment in the form of a droplet liquid or “fog” from the drying chamber with exhaust air into the cold receiver 8 of the steam ejector refrigeration machine.

In the table. 1 shows the temperature regimes and parameters of air in the thermodynamic cycle of its recirculation according to the known method using a vapor compression refrigeration machine and the proposed method using a steam ejector refrigeration machine.

Table 1

In the table. 2 presents the quality indicators of hot smoked mackerel obtained by the proposed method.

As can be seen from the table. 1 and 2, the proposed method of hot smoking of fish products allows you to:

- provide high quality finished products;

 - increase the reliability of the heat pump installation, since it does not use a mechanical drive;

- reduce specific energy consumption by 5 ... 10% by rational inclusion of a steam ejector refrigeration machine in the scheme of hot smoking of fish;

- create an environmentally friendly technology for smoking fish products through the use of water as a refrigerant.

Claims (1)

A method of hot smoking of fish products, comprising drying, boiling, smoking and cooling fish, preheating the air supplied to the drying first in the condenser of the heat pump unit, and then in the heat exchanger-recuperator; air cooling in the evaporator of the heat pump installation, obtaining saturated steam in a steam generator with electric heating elements and a safety valve with feeding it to the wire; supply of exhaust steam to a heat exchanger-recuperator for heating the air supplied for drying; removal of the formed condensate into the condensate collector and its supply in a closed cycle mode again to the steam generator, cooling the fish with chilled air in the evaporator of the heat pump installation, characterized in that when the fish products are hot smoked, a steam ejector chiller including an ejector, an evaporator, a cold receiver, an additional heat exchanger is used recuperator, condenser, thermostatic valve, condensate collector, steam generator operating in a closed thermodynamic cycle in the heat wasp; moreover, the air exhausted after drying is cooled and dried in the cold receiver of the steam ejector chiller by heat transfer from the refrigerant, which is used as water, to the air through the dividing wall of the heat exchange surface, after which the cooled and dried air is fed to the preheater in the condenser of the steam ejector chiller; the working steam obtained in a steam generator with electric heating elements and a safety valve is directed at a pressure of 0.8 ... 1.0 MPa into the ejector nozzle, while creating a reduced pressure of 0.0009 ... 0.001 MPa and a temperature of 4 ... 7 ° C in the evaporator steam ejector chiller due to ejected vapors with recirculation of refrigerant in the cold receiver, the resulting mixture of refrigerant vapor and working steam after the ejector with a pressure of 0.2 ... 0.3 MPa is sent to the condenser to preheat the drying agent, while one part of razovavshegosya water condensate in the condenser is fed to the evaporator to replenish the loss of water and the other, together with the condensate formed by cooling the air in holodopriemnike is discharged first in the condensate collector, and then the steam generator to form a closed loop; preparation of cold air for cooling fish is carried out in an additional heat exchanger-recuperator installed in the line of ejected vapors.

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