JPS637081B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a concentrator using an indirect pressurization type heat pump type evaporation system combined with a low boiling point working fluid cycle.

[Prior art]

The indirect pressure evaporation method using a low-boiling point working fluid is a method aimed at saving energy, and it is suitable for the evaporation temperature to be as low as around 30°C.
In the concentrating device using this, the temperature was suitable for the growth of bacteria in the concentrating can of the liquid to be concentrated. For this reason, it is important to sterilize the device when cleaning the device in a concentrating device that handles liquids that are problematic if bacteria are generated. When sterilization is required to prevent the proliferation of germs, high-temperature sterilization by direct injection of steam is required in addition to chemical washing, but the indirect pressure evaporation method is originally suitable for low temperatures, and the evaporation temperature is 60°C. The upper limit is considered to be around ℃.

[Problem that the invention seeks to solve]

However, due to its physical properties and properties, low boiling point working fluids cannot perform good operation due to abnormal pressure increase or thermal decomposition when exposed to high temperature conditions. For example, fluorocarbon-based refrigerants undergo thermal decomposition at temperatures above 120°C. For this reason, in the conventional method of heating the liquid to be concentrated with the working fluid in the concentrator, the working fluid is heated by the heat of the high-temperature steam used for sterilization, causing thermal decomposition, which can lead to malfunction or malfunction. cause problems.

The present invention eliminates the above-mentioned drawbacks of the conventional ones and sterilizes the concentrator by high-temperature evaporation without heating the low-boiling point working fluid, without causing deterioration or thermal decomposition of the working fluid, and without causing malfunction. The purpose of this invention is to provide a concentrating device that can perform the following steps.

[Means for solving problems]

The present invention introduces pressurized low-boiling working fluid vapor to the heating side, introduces a heating medium liquid different from the liquid to be concentrated to the heated side, and heats the heating medium with the heat of condensation of the low-boiling working fluid. An evaporator that generates heating medium vapor, the heating medium vapor generated in the evaporator is guided to the heating side, the liquid to be concentrated is introduced to the heated side, and the liquid to be concentrated is heated by the heat of condensation of the heating medium. A single-effect or multi-effect concentrating can that concentrates the liquid to be concentrated and generates the vapor of the liquid to be concentrated; A working fluid evaporator that guides the low boiling point working fluid liquid condensed in the can and heats the low boiling point working fluid using the heat of condensation of the liquid vapor to be concentrated to generate low boiling point working fluid vapor, and a working fluid evaporator that generates low boiling point working fluid vapor. directing, compressing and supplying the working fluid vapor to the heating side of the evaporator;
a compressor for circulating a working fluid, and a high-temperature steam introduction means for guiding high-temperature steam for sterilization to the heated side of the concentrating can, in a liquid vapor path to be concentrated led to the heating side of the working fluid evaporator. The concentrator is characterized in that it includes an atmosphere release valve branching from the liquid vapor path to be concentrated, and a gate valve provided downstream of the atmosphere release valve.

[Effect]

As described above, in the present invention, the liquid to be concentrated is heated not directly by the working fluid in the concentrating can (in the case of a multi-effect concentrating can, the first stage concentrating can), but indirectly through the heating medium fluid, In addition, in the refrigerant evaporator, during sterilization, the communication between the liquid to be concentrated and the concentrator is cut off by the gate valve, so the heat of the high-temperature steam used for sterilization is not directly transferred to the low-boiling point working fluid. The working fluid will not change in quality or undergo thermal decomposition, resulting in accidents that impair operating performance.

〔Example〕

An embodiment of the present invention in a single-effect concentrate can will be described with reference to the drawings. 1 is an evaporator, 2 is a concentrator, 3
is a refrigerant evaporator as a working fluid evaporator, 4 is a compressor, and 5 is an expansion valve.
refrigerant pipes 14, 15, and 16 are provided to connect the evaporator 1 and conduct a low boiling point refrigerant such as fluorocarbon as a working fluid, and to circulate the working fluid repeatedly through a gas phase and a liquid phase. A working fluid cycle path is provided for condensing and evaporating the working fluid liquid in the refrigerant evaporator 3.

20 is a concentrated liquid inlet, 9 is a concentrated liquid pump, 1
0 is a concentrate pump that discharges the concentrated liquid;
21 is a concentrated liquid outlet, 29 is a concentrated liquid vapor pipe that guides the vapor evaporated from the concentrated liquid, an atmosphere release valve 27 is branched from the middle, a gate valve 26 is provided downstream from the branch point, and a refrigerant It is connected to the heating side of the evaporator 3. 11 is a condensed water pump for discharging condensed water of the liquid vapor to be concentrated, and 22 is a condensed water outlet.
28 is a high temperature steam inlet serving as means for introducing high temperature steam for sterilization.

As a heating medium for heating the liquid to be concentrated in the concentrating can 2, instead of directly using a working fluid as in the past, heating medium vapor heated and evaporated by the working fluid in the evaporating can 1 is used. It is preferable to use an aqueous solution or water as the medium. 17 is a feed water inlet that supplies water as a heating medium, 6 is a feed water pump, 7 is a circulation water pump for unevaporated water, 18 is a circulation water outlet, 23 is a circulation line, 12 is a switching valve, 13 is a heating 8 is a distilled water pump for discharging distilled water obtained by condensation; 19 is a distilled water outlet; 24 is a circulation line; 30
is a switching valve.

The discharge side of the condensed water pump 11 is connected to the heated side of the evaporator 1 via the circulation line 25. 31 is a switching valve.

To explain the operation, the feed water supplied from the feed water inlet 17 is pumped to the evaporator 1 by the feed water pump 6.
The refrigerant vapor enters the evaporation side, where it is heated by the heat of condensation of the refrigerant vapor from the heating side, and part or all of it evaporates.
The unevaporated water is discharged out of the system from the circulating water outlet 18 by the circulating water pump 7, but part or all of it is supplied to the evaporator 1 via the circulation line 23 by the switching valve 12 as supply water. It may be circulated to the heated side.

Here, the evaporated water vapor is transferred to the heating medium steam pipe 13
The water enters the heating side of the concentrator 2 through the water, where it radiates heat to the liquid side, condenses itself, becomes distilled water, and is drained out of the system from the distilled water outlet 19 by the distilled water pump 8. When water is not needed, a part or all of it can be circulated to the feed water through the circulation line 24 by means of the switching valve 30.

In addition, the liquid to be concentrated enters the evaporation side of the concentrating can 2 from the liquid to be concentrated inlet 20 by the liquid to be concentrated pump 9, where it is heated to generate water vapor, which is then concentrated and extracted from the liquid concentrate outlet 21 by the liquid to be concentrated pump 10. and obtain the specified product.

The evaporated water vapor passes through the liquid vapor pipe 29 to be concentrated and heats the refrigerant evaporator 3, where it radiates heat to the refrigerant side, becomes condensed water, and is extracted by the condensed water pump 11 from the condensed water outlet 22. Expelled from the system. Since this condensed water contains some mist of liquid components, it is rarely recovered as distilled water, but if it does not contain volatile components, the entire amount is transferred to the supply water using the switching valve 31 so that it can be used as make-up water for the supply water. Or a part of it can be circulated through the circulation line 25.

On the other hand, on the refrigerant side, the low-pressure refrigerant vapor evaporated on the evaporation side of the refrigerant evaporator 3 enters the compressor 4 through the refrigerant pipe 14, where it is compressed and boosted in pressure, its enthalpy increases, and becomes high-pressure refrigerant vapor. It enters the heating side of the evaporator 1 through the evaporator, where it radiates heat to the water side, and condenses itself to become a high-pressure refrigerant liquid. This high-pressure refrigerant liquid passes through the refrigerant pipe 16, is depressurized by the expansion valve 5, and returns to the evaporation side of the refrigerant evaporator 3 again. In this way, a refrigerant cycle similar to the cycle of a refrigerator is formed.

This example is an energy-saving evaporator that recovers waste heat from evaporation vapor by combining a concentrator and a refrigerator cycle in low-temperature evaporation.One of the features of this example is that This is due to the fact that it is equipped with water evaporation.

The evaporator 1, the concentrator 2, and the refrigerant evaporator 3 each act as an evaporator, and although the type of evaporator does not matter, a thin film falling type evaporator with good heat transfer characteristics and power saving properties is recommended. Good to use.

Further, in the drawings, the concentrator 2 is illustrated as a single-stage concentrator, but this concentrator can also be a multi-effect concentrator, and if a multiple-effect concentrator is used, a large amount of liquid to be concentrated can be concentrated with less energy. can.

Conventionally, the washing can on the liquid side of the concentration can 2 has been treated with water washing, chemical washing, etc., but sometimes sterilization is required, and high temperature sterilization using steam is most effective for this sterilization.
The apparatus of this embodiment can easily perform sterilization using high-temperature steam without any thermal effect on the refrigerant side.
That is, the apparatus is stopped, the gate valve 26 is closed to separate the refrigerant evaporator 3, and the atmosphere release valve 27 is fully opened to open the evaporation side of the concentrator to the atmosphere. If high-temperature steam is introduced from the sterilizing steam inlet 28 in this state to sterilize the evaporation side system of the concentrator 2, the refrigerant will not be heated by the sterilizing high-temperature steam and will not be thermally decomposed.

Since this embodiment is configured and operates as described above,
The following effects can be achieved.

(1) It is an energy-saving low-temperature evaporation device.

(2) High-temperature steam sterilization of the system on the concentrated liquid side of the concentrate can can be easily and reliably performed.

(3) Distilled water can be obtained at the same time as concentrated liquid products.

(4) By returning distilled water and condensed water to the supply water, there is almost no need to replenish water, thus saving resources.

(5) The evaporator can concentrate other liquids. (Non-scaling, non-perishable liquid) (6) Since an evaporator is used, steam condenses on the heating side of the concentrator, resulting in a good heat transfer coefficient and lower equipment costs. Furthermore, since the heating side of the concentrator is steam, there is no overheating, a constant heating temperature (saturated steam temperature) is obtained, and low-temperature concentration can be reliably performed. Furthermore, by using a thin film falling type evaporator for the evaporator, it is possible to utilize temperature differences more effectively than with general heat exchange.
The device can be made smaller.

(7) By using a thin film falling type evaporator for the evaporator, concentrator, and refrigerant evaporator, the equipment can be made smaller;
Equipment costs can be reduced.

〔Effect of the invention〕

According to the present invention, when sterilizing the side of the concentrator to be concentrated, the high-temperature steam used for sterilization does not come into contact with the path of the working fluid, so the working fluid does not undergo deterioration or thermal decomposition. By using an aqueous solution that does not require a heating medium as a heating medium, it is possible to provide a concentrating device that is capable of concentrating two types of liquids at the same time, and it is possible to achieve extremely great practical effects.

[Brief explanation of the drawing]

The drawing is a flow diagram of an embodiment of the invention. 1... Evaporator, 2... Concentrator, 3... Refrigerant evaporator, 4... Compressor, 5... Expansion valve, 6... Supply water pump, 7... Circulating water pump, 8... Distilled water Pump, 9... Concentrate pump, 10... Concentrate pump, 11... Condensed water pump, 12... Switching valve, 1
3... Heating medium vapor pipe, 14, 15, 16... Refrigerant pipe, 17... Supply water inlet, 18... Circulating water outlet, 19... Distilled water outlet, 20... Liquid to be concentrated inlet, 21... Concentrate outlet, 22...Condensed water outlet,
23, 24, 25... Circulation line, 26... Gate valve, 27... Atmospheric release valve, 28... High temperature steam inlet, 29... Liquid vapor pipe to be concentrated, 30, 31... Switching valve.

Claims (1)

[Claims] 1 Pressurized low boiling point working fluid vapor is introduced to the heating side, and a heating medium liquid different from the liquid to be concentrated is introduced to the heated side, and the heating medium is heated by the condensation heat of the low boiling point working fluid. An evaporator that generates heating medium vapor by heating; the heating medium vapor generated in the evaporator is guided to the heating side, the liquid to be concentrated is led to the heated side, and the liquid to be concentrated is heated by the heat of condensation of the heating medium. A single-effect or multiple-effect concentrating can that heats the liquid to concentrate the liquid to be concentrated and generates vapor of the liquid to be concentrated; , a working fluid evaporator that guides the low-boiling working fluid liquid condensed in the evaporator and heats the low-boiling working fluid with the heat of condensation of the liquid vapor to be concentrated to generate low-boiling working fluid vapor; and the working fluid evaporator. a compressor for guiding, compressing and supplying the working fluid vapor generated in the evaporator to the heating side of the evaporator and circulating the working fluid; comprising a steam introduction means, an atmosphere release valve branching from the concentration liquid vapor path and provided downstream from the atmosphere release valve in the liquid vapor path to be concentrated led to the heating side of the working fluid evaporator; A concentrating device characterized by comprising a gate valve.