RU2379604C1 - Low-temperature vacuum material dehydration and drying device - Google Patents

Abstract

FIELD: heating systems.

SUBSTANCE: device meant for low-temperature vacuum material dehydration and drying includes vacuum process chamber in which there are process heat exchangers-evaporators with tubular channels for heat carrier, vacuum pumping assembly, assembly of charging original material to vacuum process chamber, assembly of discharging dehydrated end product, condensate collection and drain assembly, heat carrier supply assembly and heat pump. At that, vacuum process chamber is made in the form of individual units of pre-heating, pre-dehydration and final drying, cavities of each of which are connected to vacuum pumping assembly; at that, unit of final drying is made in the form of a tube with screw mechanism located in it and made in the form of blades which are fixed on the shaft and have pitch changing throughout the shaft; at that, one end of tube is connected to unit of pre-dehydration, and the other end - to finished product capacity; at that, blades from the side of finished product capacity are needle-shaped; shaft cavity is connected to heat carrier supply system; evaporation circuit of heat pump is connected to condensate collection assembly, and condenser circuit of heat pump is connected to final drying unit.

EFFECT: improving dehydration and drying efficiency of original materials, reducing energy consumption.

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Description

The invention relates to technological processes for the processing (drying) of substances and materials and can be used in food, medical and other industries, as well as for the processing and disposal of waste from poultry and pig farms.

A device for low-temperature dehydration and drying of materials in vacuum, containing a vacuum chamber with shelves for the dried material with elements for placing and transporting organic material, a heating system and nodes for loading and unloading the final product (RF patent No. 2134854, class F16B 5/06, from 1.08.1997 g.).

The disadvantage of this device is the loss of heat caused by the presence of a discharge of thermal energy released during the condensation of evaporated moisture. Ultimately, this reduces the efficiency of dehydration of materials and substances.

The closest technical solution for the combination of essential features is a device for low-temperature dehydration and drying of materials in vacuum, containing a vacuum process chamber, in which are located technological heat exchangers - evaporators for the coolant, a unit for loading the starting material into a vacuum process chamber, an unloading unit for the final dehydrated product, a unit condensate collection and drain, coolant supply unit, preheating unit and heat pump (RF patent No. 2295681, C. F16B 5/04, 03/20/2007).

The disadvantage of this device is the relatively low efficiency of drying and dehydration, the loss of biologically valuable components in the finished product, the complexity of the design of the device and high energy consumption.

The problem to which the claimed invention is directed, is to increase the efficiency of dehydration and drying of raw materials, reduce energy consumption and simplify the design of the device.

The problem is solved due to the fact that in the device for low-temperature dehydration and drying of materials in a vacuum containing a vacuum technological chamber, in which are located technological heat exchangers-evaporators with tubular channels for a coolant, a vacuum pumping unit, a unit for loading the source material into a vacuum technological chamber, a unit for unloading the final dehydrated product, a condensate collection and discharge unit, a coolant supply unit and a heat pump, a vacuum process chamber and in the form of autonomous blocks of preheating, preliminary dewatering and final drying, the cavities of each of which are connected to a vacuum pumping unit, the final drying unit being made in the form of a pipe with a screw mechanism located in it, in the form of blades fixed to the shaft with a variable pitch along the length shaft, while one end of the pipe is connected to the preliminary dewatering unit, and the other end is connected to the tank of the finished product, while the blades on the side of the tank of the finished product are made of needle, olost shaft is connected to the coolant supply system, the evaporator circuit of the heat pump is connected to a condensate collection unit and condenser of the heat pump circuit is connected to the final drying unit.

Figure 1 presents a block diagram of a device for low-temperature dehydration and drying of materials in vacuum.

Figure 2 presents a General view of the block preliminary dehydration and the associated block of final drying.

The device comprises a container for the starting material 1, a feed unit for loading the starting material 2, a vacuum process chamber 3, consisting of a pre-heating unit 4, a pre-dewatering unit 5 and a final drying unit 6. The device also comprises a vacuum pumping unit equipped with a vacuum pump 7 and a collector system 7, 8, connecting the cavity 4, 5 and 6.

The final drying unit 6 is made in the form of a pipe 9 with a screw mechanism located in it in the form of hollow blades 11 and 12 fixed to the shaft 10 with a variable pitch along the length of the shaft. One end of the pipe is connected to the preliminary dewatering unit, and the other end to the end product unloading unit13. The blades 12 from the side of the container of the finished product are made needle-shaped, and the cavity of the shaft 10 is connected to the supply system of the coolant 14, which uses hot water. Technological heat exchangers 15, located in the block 5 preliminary dehydration, are also connected to the supply system of the coolant 14. The finished product is collected in the tank 16.

The condensate collection unit 17 is connected to the condensate drainage unit 18 and to the evaporative circuit 19 of the heat pump 20, and the condenser circuit 21 of the heat pump is connected to the final drying unit 6, the pre-dewatering unit 5 and the pre-heating unit 4.

The device operates as follows.

The source material with a temperature of 12-20 ° C and a humidity of 80-95% by means of the loading unit 2 enters from the tank 1 into the pre-heating unit 4, where it is heated under vacuum of 0.1 bar to a temperature of evaporation of moisture + 55 ° C.

The heated initial product then goes to the pre-dewatering unit 5. Hot water enters the process heat exchangers 15 located in this unit. Under the action of heat in block 5, moisture evaporates from the surface of the original product to a moisture value of 30-40%. Then the pre-dehydrated product enters the final drying unit, where at a vacuum of 0.1 bar and a temperature of + 55 ° C the final drying of the product to a moisture content of 7-10% takes place.

The steam formed in block 5 and 6 enters the condensate collection unit 17 and merges into the condensate drainage unit 18. A part of the steam is carried away by the flow pumped out by the vacuum pump 7, which is thrown out.

In the cavity of the shaft 10 and the blades 11 flows the coolant through the supply system of the coolant 14, heating the screw mechanism to a temperature of 60 ° C.

Intensive mixing on the screw spiral leads to constant contact of the lumpy product, increasing its temperature and further evaporation of moisture. In the area of the auger with needle blades, the final drying occurs, the lumps break up and the product is completely homogenized. The return of part of the energy spent on the evaporation of moisture in block 5 is carried out by supplying energy from the condensate collecting unit 17 to the evaporative circuit of the heat pump 20, and the re-supply of thermal energy to block 6 is carried out by the condenser circuit 21 of the heat pump 20.

Thus, increasing the heat sink intensity in the final drying unit 6, in the preliminary evaporation unit 5 is a highly economical drying process, increases the thermal energy conversion coefficient and, ultimately, the drying efficiency of the starting material.

Claims (1)

A device for low-temperature dehydration and drying of materials in vacuum, containing a vacuum process chamber, in which are located technological heat exchangers-evaporators with tubular channels for the coolant, a vacuum pumping unit, a source unit for loading the source material into a vacuum technological chamber, an unloading unit for the final dehydrated product, a collection unit, and condensate drain, coolant supply unit and heat pump, characterized in that the vacuum process chamber is made in the form of autonomous units pre-heating, pre-dewatering and final drying, the cavities of each of which are connected to the vacuum pumping unit, and the final drying unit is made in the form of a pipe with a screw mechanism located in it in the form of blades fixed to the shaft with a variable pitch along the shaft length, with one end the pipe is connected to the pre-dewatering unit, and the other end to the finished product’s tank, while the blades on the side of the finished product’s tank are needle-shaped, the shaft cavity is connected to subject supplying coolant, the evaporator circuit of the heat pump is connected to a condensate collection unit and condenser of the heat pump circuit is connected to the final drying unit.

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