Disclosure of Invention
In order to overcome the problems in the prior art, a system and a method which are strong in adaptability, high in concentration degree of concentrated materials and high in energy utilization rate and can improve the concentration degree of a mechanical vapor recompression system are particularly provided.
In order to achieve the technical purpose, the technical scheme of the invention is as follows:
the invention provides a system capable of improving the concentration degree of a mechanical vapor recompression system, which adopts the following technical scheme:
a system capable of improving the concentration degree of a mechanical vapor recompression system is characterized in that: the device comprises an evaporator, a compressor, a heat compensator and a discharge pump, wherein a concentrated material discharge port at the bottom of the evaporator is connected with the heat compensator through a pipeline; the upper vapor phase outlet of the heat compensator is connected with the bottom vapor phase inlet of the evaporator through a pipeline; the evaporator is connected with an inlet of the compressor through a pipeline, and an outlet of the compressor is connected with a shell-side steam inlet of the evaporator through a pipeline; the bottom of the heat compensator is connected with a discharge pump through a pipeline, and the outlet of the discharge pump is divided into two paths: one path is used as circulation and connected with the heat compensator through a pipeline, and the other path is used as discharge and connected with the product storage tank through a pipeline.
Furthermore, a washing and separating device can be arranged on a pipeline between the evaporator and the inlet of the compressor, so that concentrated components in steam generated by evaporation of the evaporator are removed, and the purity of the steam is improved. The washing and separating device can be a device with washing and separating functions, such as a spray tower, a washing tower, a rectifying tower and the like.
The feeding storage tank is connected with a heat exchanger through a feeding pump, and the heat exchanger is connected with the evaporator and the condensate storage tank.
The pipeline of the discharge port of the concentrated material at the bottom of the evaporator is provided with an automatic flow control system, the concentrated material at the bottom of the evaporator can be conveyed in a pumping mode, and the gravity-free conveying, preferably gravity-free conveying, of the concentrated material can also be realized by adjusting the relative installation position of the evaporator and the heat compensator.
The heat compensator is provided with a liquid level controller, and a circulating pipeline at the outlet of the discharging pump is used as a forced circulating pipeline of the heat compensator; the discharge pipeline of the discharge pump is provided with a flow control system.
The system adopts an automatic control mode, including but not limited to the following control modes: PLC control, DCS control, etc.
The form of the heat compensator includes but is not limited to the following forms: dividing wall type heat exchanger, electric heater and electromagnetic radiation heater.
The external heat source of the heat compensator includes but is not limited to the following modes: electrical heating, steam heating and heating of hot liquid media.
A method capable of improving the concentration degree of a mechanical vapor recompression system comprises the following technical scheme:
when the mechanical vapor recompression system needs to provide supplementary heat from the outside because the heat dissipation loss is larger than the work done by the compressor, a concentrated material outlet at the bottom of the evaporator is connected with the heat compensator, and the concentrated material in the evaporator is heated by the heat compensator to become a vapor-liquid two phase; after the vapor phase and the liquid phase are separated, the vapor phase enters the evaporation system to be used as supplementary heat of a mechanical vapor recompression system, and enters a compressor together with secondary vapor generated by an evaporator to be used as an evaporator heat source after compression and temperature rise; the residual re-concentrated material after being further heated and concentrated by the heat compensator is taken as a concentrated material product and discharged out of the system by a discharge pump.
Further, the method comprises the following specific steps:
s1, feeding the concentrated material at the bottom of the evaporator into a heat compensator through a pipeline, heating the concentrated material by the heat compensator to change the concentrated material into a vapor-liquid two phase, feeding the vapor phase into the evaporator through a pipeline from a vapor phase inlet at the bottom of the evaporator, and feeding the vapor phase and the secondary steam generated by evaporation of the evaporator into a compressor through a pipeline; the steam is compressed by a compressor and then becomes high-temperature high-pressure steam which is used as a heat source of an evaporator and enters the shell of the evaporator through a pipeline to heat and evaporate feed liquid; the steam heats the feeding liquid to become condensate, the condensate enters the heat exchanger to preheat the feeding liquid conveyed by the feeding pump, and the condensate finally enters the condensate storage tank.
S2, the concentrated material is heated by a heat compensator and then becomes a vapor phase and a liquid phase, wherein the liquid phase re-concentrated material is divided into two paths by a pipeline through a discharge pump: one path enters a heat compensator through a pipeline and enters circulation; one path is discharged to a product storage tank through a pipeline to be used as a discharge.
Furthermore, the vapor phase generated by heating the concentrated material by the heat compensator can enter a pipeline through a pipeline, enters a compressor together with the secondary steam generated by evaporation of the evaporator through the pipeline, and is compressed by the compressor to become high-temperature high-pressure steam which is used as a heat source of the evaporator.
According to the method for improving the concentration degree of the mechanical vapor recompression system, the concentration degree of the liquid-phase re-concentrated material obtained by the heat compensator is 5-20% higher than that of the traditional heat compensation scheme under the condition that the energy consumption of the system is the same.
The method is suitable for an evaporation concentration system of organic matter mixture, aqueous solution and salt solution thereof.
Furthermore, the device is suitable for mechanical vapor recompression systems of non-azeotropic systems of organic matters, water and organic matter mixtures, in particular to concentration systems of ethylene glycol, propylene glycol or diethylene glycol or mixture water solutions thereof.
The heat compensator utilizes an external heat source to heat the concentrated material discharged by the evaporator of the mechanical vapor recompression system to generate steam, and the generated steam is used as supplementary heat and enters the evaporation system.
The heat compensator heats the concentrated material discharged from the evaporator of the mechanical vapor recompression system by using an external heat source to generate steam, the generated steam is used as supplementary heat, enters the mechanical vapor recompression evaporation system through an evaporator or a secondary steam pipeline before entering a compressor or a pipeline and equipment before an air inlet of the compressor, and enters the compressor together with the secondary steam generated by the evaporator, and the method comprises the following steps: evaporator bottom air intake, compressor air intake, piping before compressor air intake, and the like.
Furthermore, a washing and separating device can be arranged on a pipeline between the evaporator and the inlet of the compressor, so that concentrated components in steam generated by evaporation of the evaporator are removed, and the purity of the steam is improved. The washing and separating device can be a device with washing and separating functions, such as a spray tower, a washing tower, a rectifying tower and the like.
The invention has the advantages and beneficial effects that:
1. compared with the traditional heat compensation scheme, in the system and the method for improving the concentration degree of the mechanical vapor recompression system, the concentrated material concentrated by the mechanical vapor recompression system is subjected to heat exchange with the heat compensator before being discharged out of the system, and the concentration degree is 5-20% higher than that of the traditional heat compensation scheme. In the present invention, the external heat additionally injected into the system has two effects: firstly, the heat loss of the system is compensated, and the stable operation of the system is ensured; and secondly, the concentrated material concentrated by the mechanical vapor recompression system is further heated and concentrated, so that the concentration degree of the concentrated material is improved. In the traditional heat supplementing scheme, the heat of the external extra injection system only can generate the first effect and cannot generate the second effect, so that the application of the heat of the external extra injection system is increased, the concentration degree of the concentrated material is obviously improved, the concentration degree is 5-20% higher than that of the traditional heat supplementing scheme, the energy utilization rate is more sufficient, and the effect is better.
2. The application is particularly suitable for the concentration process of the material with the boiling point rising along with the concentration increase, and the concentration degree of the concentrated material can be further improved under the condition of not increasing the temperature rise capacity of the steam compressor.
3. When the system is driven, the heat supplementing scheme provided by the invention is adopted, the system heating can be directly used for concentration during driving, and the driving heat can be fully utilized.
4. The technical scheme of the invention has the advantages of simple flow, strong operability, wide application range and high energy utilization rate, and can be widely applied to various mechanical vapor recompression systems.
Detailed Description
For better illustration of the present invention, the technical solution of the present invention will be described in more detail by embodiments, which are a part of embodiments of the present invention, but not all embodiments, with reference to the accompanying drawings. All other embodiments obtained by those skilled in the art without any creative effort belong to the protection scope of the present invention based on the technical solution of the present invention.
Example 1
A system capable of improving the concentration degree of a mechanical vapor recompression system comprises an evaporator 1, a compressor 2, a heat compensator 4 and a discharge pump 7, wherein a discharge hole of a concentrated material at the bottom of the evaporator 1 is connected with the heat compensator 4 through a pipeline; the upper vapor phase outlet of the heat compensator 4 is connected with the bottom vapor phase inlet of the evaporator 1 through a pipeline; the evaporator 1 is connected with an inlet of the compressor 2 through a pipeline, and an outlet of the compressor 2 is connected with a shell-side steam inlet of the evaporator 1 through a pipeline; the concentrated material discharge gate passes through the pipeline with discharge pump 7 again in the 4 bottoms of concurrent heating ware and links to each other, 7 exports of discharge pump divide into two the tunnel: one path is used as circulation and connected with the heat compensator 4 through a pipeline, and the other path is used as discharge and connected with the product storage tank 8 through a pipeline.
Furthermore, a washing and separating device 9 can be arranged on a pipeline between the evaporator 1 and the inlet of the compressor 2, so that concentrated components in steam generated by evaporation of the evaporator 1 can be removed, and the purity of the steam can be improved. The washing and separating device 9 may be a device having a washing and separating function, such as a spray tower, a washing tower, or a rectifying tower.
The feeding storage tank 3 is connected with a heat exchanger 6 through a feeding pump 5, and the heat exchanger 6 is connected with the evaporator 1 and a condensate storage tank.
The pipeline of the discharge port of the concentrated material at the bottom of the evaporator 1 is provided with an automatic flow control system, the concentrated material at the bottom of the evaporator 1 can be conveyed in a pumping mode, and the gravity self-flow conveying, preferably gravity self-flow conveying, of the concentrated material can also be realized by adjusting the relative installation positions of the evaporator 1 and the heat compensator 4.
The heat compensator 4 is provided with a liquid level controller, and a circulating pipeline at the outlet of the discharge pump 7 is used as a forced circulating pipeline of the heat compensator 4; the discharge pipeline of the discharge pump 7 is provided with a flow control system.
The system adopts an automatic control mode, including but not limited to the following control modes: PLC control, DCS control, etc.
The form of the heat compensator 4 includes, but is not limited to, the following forms: dividing wall type heat exchanger, electric heater and electromagnetic radiation heater.
The external heat source of the heat compensator 4 includes, but is not limited to, the following modes: electrical heating, steam heating and heating of hot liquid media.
Example 2
A method capable of improving the concentration degree of a mechanical vapor recompression system comprises the following technical scheme:
when the mechanical vapor recompression system needs to provide supplementary heat from the outside because the heat dissipation loss is larger than the work of the compressor 2, a concentrated material outlet at the bottom of the evaporator 1 is connected with the heat compensator 4, and the concentrated material in the evaporator 1 enters the heat compensator 4 to be heated and then becomes a vapor-liquid two phase; after the vapor-liquid two-phase separation, the vapor phase enters the evaporation system to be used as supplementary heat of a mechanical vapor recompression evaporation system, and enters a compressor 2 together with secondary vapor generated by an evaporator 1 to be used as a heat source of the evaporator 1 after compression and temperature rise; the residual re-concentrated material after being further heated and concentrated by the heat compensator 4 is taken as a concentrated material product and discharged out of the system by the discharge pump 7.
Further, the method comprises the following specific steps:
s1, feeding the concentrated material at the bottom of the evaporator 1 into the heat compensator 4 through a pipeline, heating the concentrated material by the heat compensator 4 to change the concentrated material into a vapor-liquid two phase, feeding the vapor phase into the evaporator 1 through a pipeline from a vapor phase inlet at the bottom of the evaporator 1, and feeding the vapor phase and the secondary vapor generated by the evaporation of the evaporator 1 into the compressor 2 through a pipeline; the steam is compressed by a compressor 2 and then becomes high-temperature high-pressure steam which is used as a heat source of an evaporator 1 and enters the shell pass of the evaporator 1 through a pipeline to heat and evaporate feed liquid; the steam heats the feed liquid to become condensate, the condensate enters the heat exchanger 6 to preheat the feed liquid conveyed by the feed pump 5, and the condensate finally enters the condensate storage tank 10.
S2, the concentrated material is heated by the heat compensator 4 and then becomes a vapor-liquid two-phase, wherein the liquid-phase re-concentrated material is divided into two paths by a pipeline through a discharge pump 7: one path enters a heat compensator 4 through a pipeline and enters circulation; one way is discharged to a product storage tank 8 through a pipeline as discharging.
Further, the vapor phase generated by heating the concentrated material by the heat compensator 4 can enter a pipeline through a pipeline, enters the compressor 2 through the pipeline together with the secondary steam generated by evaporation of the evaporator 1, and is compressed by the compressor 2 to become high-temperature high-pressure steam which is used as a heat source of the evaporator 1.
According to the method for improving the concentration degree of the mechanical vapor recompression system, the concentration degree of the liquid-phase re-concentrated material obtained by the heat compensator 4 is 5-20% higher than that of the traditional heat compensation scheme under the condition that the energy consumption of the system is the same.
The method is suitable for an evaporation concentration system of organic matter mixture, aqueous solution and salt solution thereof.
The method is suitable for mechanical vapor recompression systems of non-azeotropic systems of organic matters, water and organic matter mixtures, in particular to concentration systems of ethylene glycol, propylene glycol or diethylene glycol or mixture water solutions thereof.
The heat compensator 4 heats the concentrated material discharged from the mechanical vapor recompression system evaporator 1 by using an external heat source to generate steam, and the generated steam is used as supplementary heat and enters the evaporation system.
The heat compensator 4 heats the concentrated material discharged from the evaporator 1 of the mechanical vapor recompression system by using an external heat source to generate steam, the generated steam is used as supplementary heat, enters the interior of the mechanical vapor recompression system through a secondary steam pipeline before the evaporator 1 or enters the compressor 2 or a pipeline, equipment and the like before an air inlet of the compressor 2, and enters the compressor 2 together with the secondary steam generated by the evaporator 1, and the method includes but is not limited to the following ways: the bottom air inlet of the evaporator 1, the air inlet of the compressor 2, the pipeline before the air inlet of the compressor 2, and the like.
Furthermore, a washing and separating device 9 can be arranged on a pipeline between the evaporator 1 and the inlet of the compressor 2, so as to remove concentrated components in steam generated by evaporation of the evaporator 1 and improve the purity of the steam. The washing and separating device 9 may be a device having a washing and separating function, such as a spray tower, a washing tower, or a rectifying tower.
Example 3
The following describes a heat compensation scheme of the conventional mechanical vapor recompression evaporation system and a new method provided by the present invention in comparison with the accompanying drawing 1:
the existing heat compensation method of the traditional mechanical vapor recompression system comprises the following steps: when the mechanical vapor recompression system needs to supply supplementary heat from the outside because the heat dissipation loss is larger than the work of the vapor compressor 2, a vapor branch pipe is arranged on a pipeline connecting the compressor 2 and the shell pass vapor inlet of the evaporator 1 and used for inputting the external supplementary vapor into the shell pass of the evaporator 1 so as to supplement the heat loss of the system and ensure the normal operation of the system.
Fig. 1 is a schematic flow chart of a system and method for increasing the concentration level of a mechanical vapor recompression system according to the present invention. The process is as follows: when the mechanical vapor recompression system needs to provide supplementary heat from the outside because the heat dissipation loss is larger than that of the vapor compressor 2 to do work, a concentrated material outlet at the bottom of the evaporator 1 is connected with the heat compensator 4, and the concentrated material in the evaporator 1 enters the heat compensator 4 to be heated and then becomes a vapor-liquid two phase; after the vapor-liquid two-phase separation, the vapor phase enters the evaporation system to be used as the supplementary heat of a mechanical vapor recompression system, and enters a vapor compressor 2 together with secondary vapor generated by the evaporator 1 to be used as a heat source of the evaporator 1 after compression and temperature rise; the residual re-concentrated material after being further heated and concentrated by the heat compensator 4 is taken as a concentrated material product and discharged out of the system by the discharge pump 7.
Compared with the heat compensation scheme of the traditional mechanical vapor recompression system and the new method provided by the invention, when the mechanical vapor recompression system needs external additional heat compensation:
adopt current traditional concurrent heating scheme: the external heat compensation is directly used for inputting fresh steam into the shell pass of the evaporator 1 to be used as the heat compensation of the mechanical steam recompression system. Under this kind of scheme, the heat that the external world provided can not heat 1 bottom exhaust concentrated material of evaporimeter, and the heat that the external world provided can't further concentrated the evaporation to concentrated material, and supplementary heat utilization rate is low.
The new method provided by the invention is adopted: external heat supplement directly heats the concentrated material discharged from the bottom of the evaporator 1 to generate steam, and the steam enters a mechanical steam recompression system to serve as supplementary heat. In the scheme provided by the invention, external supplementary heat directly acts on the concentrated material discharged from the bottom of the evaporator 1, the concentrated material is evaporated to generate steam, the concentrated material is further concentrated under the action of the external supplementary heat, and the concentration degree is further improved and is 5-20% higher than that of the traditional heat supplementing scheme; meanwhile, steam generated by the concentrated material under the action of external supplementary heat enters the mechanical steam recompression system to be used as supplementary heat, so that the stable and normal operation of the system is ensured. The new method provided by the invention obviously improves the energy utilization rate of the supplementary heat, has simple and reliable flow, not only ensures the stable and normal operation of the system, but also improves the concentration degree of the concentrated materials of the system.
Fig. 1 is a schematic flow chart of a system and method for increasing the concentration level of a mechanical vapor recompression system according to the present invention. When the mechanical vapor recompression system needs to provide supplementary heat from the outside because the heat dissipation loss is greater than the work of the vapor compressor 2, the system capable of improving the concentration degree of the mechanical vapor recompression system comprises an evaporator 1, the compressor 2, a heat compensator 4 and a discharge pump 7, wherein a concentrated material discharge port at the bottom of the evaporator 1 is connected with the heat compensator 4 through a pipeline; the upper vapor phase outlet of the heat compensator 4 is connected with the bottom vapor phase inlet of the evaporator 1 through a pipeline; the evaporator 1 is connected with an inlet of the compressor 2 through a pipeline, and an outlet of the compressor 2 is connected with a shell-side steam inlet of the evaporator 1 through a pipeline; the outlet of the reconcentrated material at the bottom of the heat compensator 4 is connected with the discharging pump 7 through a pipeline, and the outlet of the discharging pump 7 is divided into two paths: one path is used as circulation and connected with the heat compensator 4 through a pipeline, and the other path is used as discharge and connected with a product storage tank through a pipeline.
A system capable of improving the concentration degree of a mechanical vapor recompression system comprises the following operation flow steps:
s1, feeding the concentrated material at the bottom of the evaporator 1 into the heat compensator 4 through a pipeline, heating the concentrated material by the heat compensator 4 to change the concentrated material into a vapor-liquid two phase, feeding the vapor phase into the evaporator 1 through a pipeline from a vapor phase inlet at the bottom of the evaporator 1, and feeding the vapor phase and the secondary vapor generated by evaporation of the evaporator 1 into the compressor 2 through a pipeline; the steam is compressed by a compressor 2 and then becomes high-temperature high-pressure steam which is used as a heat source of an evaporator 1 and enters the shell pass of the evaporator 1 through a pipeline to heat and evaporate feed liquid; the steam heats the feed liquid to become condensate, the condensate enters the heat exchanger 6 to preheat the feed liquid conveyed by the feed pump 5, and the condensate finally enters the condensate storage tank 10.
S2, heating the concentrated material by the heat compensator 4 to become a gas phase and a liquid phase, and dividing the liquid phase re-concentrated material into two paths by a pipeline through a discharge pump 7: one path enters a heat compensator 4 through a pipeline and enters circulation; one path is discharged to a product storage tank through a pipeline to be used as a discharge. Further, the vapor phase generated by heating the concentrated material by the heat compensator 4 can enter the pipeline through the pipeline, enters the compressor 2 through the pipeline together with the secondary steam generated by the evaporation of the evaporator 1, and is compressed by the compressor 2 to become high-temperature high-pressure steam which is used as a heat source of the evaporator 1. By adopting the method, the built device can be conveniently technically improved.
An automatic flow control system is arranged on a discharge pipeline of the concentrated material at the bottom of the evaporator 1, and a liquid level controller is arranged on the heat compensator 4; the material conveying can adopt a pumping mode, and the gravity conveying, preferably gravity conveying, of the concentrated material can also be realized by adjusting the relative installation positions of the evaporator 1 and the heat compensator 4.
A circulating pipeline is arranged at the outlet of the discharging pump 7 and is used as a forced circulating pipeline of the heat compensator 4; the discharge pipeline of the discharge pump 7 is provided with a flow control system.
The system capable of improving the concentration degree of the mechanical vapor recompression system provided by the invention adopts an automatic control mode, including but not limited to the following control modes: PLC control, DCS control, etc.
It should be noted that, a washing and separating device 9 may be disposed on the pipeline between the evaporator 1 and the inlet of the compressor 2 to remove the concentrated components in the steam generated by evaporation in the evaporator 1 and improve the purity of the steam, and the washing and separating device 9 may be a device having a washing and separating function, such as a spray tower, a washing tower/a rectifying tower, etc.
The system and the method for improving the concentration degree of a mechanical vapor recompression system are described with reference to fig. 1, and when the method is used for treating 10% ethylene glycol solution for concentration, specific parameters are as follows: feeding 2 tons/hour, and concentrating the 10% ethylene glycol solution by a mechanical vapor recompression system to obtain 55% ethylene glycol concentrated solution. When the mechanical steam recompression evaporation system needs to supplement 20KW per hour due to heat loss, the concentration of the obtained concentrated solution can reach 60% by adopting the technical scheme system provided by the invention.
The system and the method for improving the concentration degree of a mechanical vapor recompression system are described with reference to fig. 1, and when the method is used for treating 6% diethylene glycol solution for concentration, the specific parameters are as follows: feeding 2 tons/h, and concentrating the 6% diethylene glycol solution by a mechanical vapor recompression evaporation system to obtain a 60% diethylene glycol concentrated solution. When the mechanical steam recompression evaporation system needs to supplement 20KW per hour due to heat loss, the concentration of the obtained concentrated solution can reach 70% by adopting the heat supplementing technical scheme provided by the invention.
The present invention is schematically described in the above with reference to the drawings, and the system and method for increasing the degree of concentration in a mechanical vapor recompression system are provided. Those skilled in the art will appreciate that other persons may devise similar methods in the light of the teachings of this invention. It is specifically intended that all similar arrangements of the invention be considered as falling within the scope of the invention as claimed, without departing from the central spirit thereof.