CN211545999U

CN211545999U - Closed circulation evaporation and condensation system for treating high-salt and high-COD wastewater

Info

Publication number: CN211545999U
Application number: CN201922213470.7U
Authority: CN
Inventors: 孙勇; 姚冰; 余三江; 李迪
Original assignee: Anhui Tongsu Environmental Protection Technology Co ltd
Current assignee: Anhui Tongsu Environmental Protection Technology Co ltd
Priority date: 2019-12-11
Filing date: 2019-12-11
Publication date: 2020-09-22
Anticipated expiration: 2029-12-11

Abstract

The utility model provides a closed circulation evaporation condensing system for contain high COD waste water treatment of high salt. A closed circulation evaporation condensing system for containing high COD waste water treatment of high salt includes: a wastewater tank; one end of the waste water pump is connected with the waste water tank; the evaporation tower is arranged on one side of the wastewater trough; a condenser disposed within the evaporation tower; the spray pipe is arranged in the evaporation tower, is connected with the waste water pump and is positioned above the condenser; the primary heat recoverer is connected with the evaporation tower. The utility model provides a closed circulation evaporation condensing system for containing high COD waste water treatment of high salt has the advantage that the cost is lower, ordinary pressure evaporation, middle and low temperature evaporation, high-efficient evaporation, energy-conserving evaporation, stable evaporation.

Description

Closed circulation evaporation and condensation system for treating high-salt and high-COD wastewater

Technical Field

The utility model relates to a waste water treatment technical field especially relates to a closed circulation evaporation condensing system for containing high COD waste water treatment of high salt.

Background

With the rapid development of national economy in China, a large amount of salt-containing wastewater is generated in the fields of printing and dyeing, papermaking, chemical industry, oil refining, seawater utilization and the like. If the salt-containing wastewater is directly or diluted and discharged, on one hand, water resource waste is caused; on the other hand, the method has a bad influence on the environment, and thus research on an effective treatment method for salt-containing wastewater is urgent. The existing MVR and multi-effect evaporation treatment technologies have high investment and operation cost; belongs to high-voltage equipment, and is difficult to operate and manage; easy coking and blockage, and the like, and limits the popularization and the application.

Therefore, it is necessary to provide a closed cycle evaporative condensation system for treating wastewater with high salt content and high COD to solve the above technical problems.

SUMMERY OF THE UTILITY MODEL

The technical problem solved by the utility model is to provide a closed circulation evaporation condensing system who is used for containing high salt high COD waste water treatment of cost lower, ordinary pressure evaporation, well low temperature evaporation, high-efficient evaporation, energy-conserving evaporation, stable evaporation.

In order to solve the technical problem, the utility model provides a closed circulation evaporation condensing system for containing high COD waste water treatment of high salt, include: a wastewater tank; one end of the waste water pump is connected with the waste water tank; the evaporation tower is arranged on one side of the wastewater trough; a condenser disposed within the evaporation tower; the spray pipe is arranged in the evaporation tower, is connected with the waste water pump and is positioned above the condenser; the primary heat recoverer is connected with the evaporation tower; the secondary heat recoverer is connected with the primary heat recoverer; the condensation tower is connected with the secondary heat recoverer and the primary heat recoverer; the circulating fan is arranged in the condensing tower; the evaporator is arranged in the condensation tower and is positioned below the circulating fan; the throttling element is respectively connected with the condenser and the evaporator; the inlet and the outlet of the compressor unit are respectively connected with the condensing tower and the evaporator; and the concentrated liquid pump is connected with the evaporation tower and the wastewater tank.

Preferably, the top and one side of the evaporation tower are both provided with connecting pipes, and the two connecting pipes are both connected with the primary heat recoverer.

Preferably, the condenser is arranged in the middle of the inside of the evaporation tower, the spray pipe is arranged at the upper part of the condenser, and the spray pipe and the condenser are arranged in parallel and staggered layers.

Preferably, three substances of water, air and refrigerant are used as circulating heat-carrying media of the system; two substances, namely water and air, are used as circulating carrier media of the system, and the heat-carrying media and the carrier media are synchronously circulated in parallel in the system, so that the synchronous operation of heat transfer and mass transfer is realized.

Preferably, the system adopts the technology of closed self-circulation evaporation and condensation, the evaporation of the waste water and the condensation of the purified water are respectively and simultaneously carried out in the closed system, and the energy is recycled at the evaporation end and the condensation end under the support of the air path circulation and the refrigerant circulation.

Preferably, the system adopts a double-path heat recovery technology of air and refrigerant, and recovers heat in the heat-carrying medium to the maximum extent; and the temperature is reduced at the air circulation condensation end, so that the heat balance of the heat pump system under the closed circulation working condition is ensured.

Preferably, the system adopts a water evaporation technology under the working conditions of normal pressure and medium and low temperature (less than or equal to 55 ℃), and effectively avoids the problems of scaling and organic matter coking blockage caused by the treatment of high-salt high-COD wastewater.

Preferably, the system adopts three different temperature areas of a primary heat recoverer, a secondary heat recoverer, an evaporator and the like to gradually and gradiently cool the high-temperature high-humidity circulating air at the condensation end of the air circulation, and is used for improving the water outlet efficiency of condensed water.

Preferably, the evaporation and condensation of water in the system are evaporation and condensation in a closed circulation state, heat absorbed by evaporation and heat released by condensation are balanced, so that no additional external heat source is needed to be input in the evaporation and condensation processes, the system is heated in the form of electric energy input, however, in order to drive heat in the heat-carrying medium to circulate and carry at the evaporation and condensation ends, certain external energy must be consumed, the system does work in the form of electric energy input, the external energy must do work and then generate certain redundant heat, when the heat is accumulated to a certain degree, the accumulated heat must be discharged out of the system, and therefore, an external cold source is used for realizing the heat balance inside the system.

Compared with the prior art, the utility model provides a closed circulation evaporation condensing system for containing high COD waste water treatment of high salt has following beneficial effect:

the utility model provides a closed circulation evaporation and condensation system for treating high-salt and high-COD wastewater, which heats and evaporates the wastewater under normal pressure, and the system is safer and more stable in operation; a large number of plastic parts and pipelines can be used, so that the corrosion resistance of the system is effectively improved, and the cost is reduced; the volatilization amount of organic solutes in the wastewater is reduced, and the effluent quality is improved;

the waste water is subjected to heat absorption and evaporation in a water film shape on the surface of the heat exchange tube in a medium and low temperature (less than or equal to 55 ℃), and the blockage of a system pipeline caused by heating, scaling and coking of solutes in the waste water is effectively avoided; the denaturation of solute is avoided, and the volatilization amount of organic solute in the wastewater is reduced;

the heat required by the waste water heating realizes closed circulation, the heat released in the steam condensation process is recovered at the evaporator end, and the recovered heat is carried to a condenser by applying the heat pump principle to continuously supply heat for the waste water evaporation; in the first-stage heat recoverer, the high-temperature and high-humidity circulating air from the evaporation tower and the low-temperature and high-humidity circulating air from the evaporator are subjected to total heat exchange, so that the circulating air re-entering the evaporation tower absorbs heat to be in a state of higher temperature and low relative humidity, and the heat recovery of the circulating air is realized. The heat recovery of the fluorine path and the air path is realized, so that the energy consumption is further reduced, and the energy-saving evaporation of the wastewater is realized;

the waste water is evaporated on the surface of the heat exchange tube of the heat pump condenser, the heat transfer distance is extremely short, the heat transfer coefficient is high, and the evaporation efficiency is effectively improved; three heat-carrying substances (refrigerant, air and water) and a carrier substance (air) synchronously circulate, and heat transfer and mass transfer are synchronous; three different temperature areas are formed at the air circulation condensation end by arranging a primary heat recoverer, a secondary heat recoverer and an evaporator, so that the circulation air is gradually and gradiently cooled, the condensation efficiency of water vapor is greatly improved, and the high-efficiency evaporation of the waste water is realized;

the cold end of the system is provided with a heat unloading device, so that the heat accumulated in the system is unloaded as required, the system can be ensured to stably run for a long time, and the stable evaporation of the waste water is realized.

Drawings

FIG. 1 is a far-away block diagram of a closed cycle evaporative condensation system for treating wastewater containing high salt and high COD provided by the utility model.

Reference numbers in the figures: 1. the system comprises a waste water tank, 2, a waste water pump, 3, a condenser, 4, a spray pipe, 5, an evaporation tower, 6, a primary heat recoverer, 7, a secondary heat recoverer, 8, a condensation tower, 9, a circulating fan, 10, an evaporator, 11, a throttling element, 12, a compressor unit, 13 and a concentrated liquid pump.

Detailed Description

The present invention will be further described with reference to the accompanying drawings and embodiments.

Referring to fig. 1, in a first embodiment of the present invention, a closed cycle evaporative condensation system for high-salt and high-COD wastewater treatment includes an inverse carnot cycle heat pump subsystem for heating evaporative wastewater and condensing clean water, which are sequentially connected to form a circulation loop, the heat pump subsystem includes: a compressor unit 12 (including main components such as an oil separator, a liquid storage tank, a drying filter, a liquid viewing mirror, a gas-liquid separator and the like, which are not marked in fig. 1), (an evaporation cooling type titanium pipeline) condenser 3, a throttling element (an electronic expansion valve) 11, an evaporator 10, and a matched refrigerant pipeline, a valve part and the like; a waterway subsystem for wastewater delivery, spraying and collection discharge, the waterway subsystem comprising: the device comprises a waste water pump 2, a spray pipe 4, a concentrated liquid pump 13, a waste water tank 1, and matched waterway pipelines, valves and the like; the air path subsystem is used for carrying steam, recovering heat and realizing closed circulation, and comprises an evaporation tower 5, a primary heat recoverer 6, a secondary heat recoverer 7, a circulating fan 9, a condensation tower 8, and matched air path pipelines, valve members and the like; and a PLC intelligent control subsystem (not shown in the figure) for realizing automatic control of the whole system.

The refrigerant gas with low temperature and low pressure is sucked into a suction cavity of a compressor unit 12, works by a compressor, is compressed into high-temperature and high-pressure gas, enters a (evaporation cooling type titanium tube) condenser 3, transfers heat to a water film on the surface of the titanium tube with relatively low temperature, the state of the refrigerant after condensation and heat release is converted from the high-temperature and high-pressure gas into high-temperature and high-pressure liquid with reduced temperature, and then is discharged out of the condenser 3, is throttled and reduced in pressure by a throttling element (electronic expansion valve) 11, the state of the refrigerant is converted from the high-temperature and high-pressure liquid into a low-temperature and low-pressure gas-liquid mixed state, enters an evaporator 10, absorbs the heat of water vapor on the surface of the evaporator 10, and the state of the refrigerant.

In the process of waste water evaporation and condensation, waste water stock solution in a waste water tank 1 outside the system is preheated to reach a certain temperature, is sprayed to the surface of an (evaporation cooling type titanium pipe) condenser 3 to form a uniform water film in a water drop shape through a waste water pump 2 and a spray pipe 4, partial raw water can form water vapor (unsaturated) after absorbing heat from a high-temperature high-pressure refrigerant, and is conveyed to a primary heat recoverer 6 and a secondary heat recoverer 7 with reduced temperature through circulating air, the water vapor releases heat and is condensed into water drops to be separated out, waste water residual liquid which is not evaporated in a titanium pipe condenser can be circularly and repeatedly sprayed to the surface of the titanium pipe, so that the concentration of the residual liquid can continuously rise until reaching a preset concentration and is intensively discharged to the outside of the system for additional treatment, and the evaporation of the waste water is carried out under normal pressure, medium and low temperature environments.

The state of partial raw water is converted from liquid state to gas state, and the process needs to absorb a large amount of latent heat of vaporization; meanwhile, the state of the refrigerant is converted from a gas state to a gas-liquid mixed state and finally to a liquid state, and a large amount of latent heat of vaporization is released in the process. The state (gas state and liquid state) of the substances (water and refrigerant) inside and outside the condenser (3) is changed, and the latent heat of vaporization released and absorbed during state conversion is far greater than the sensible heat released and absorbed during state non-conversion (only temperature rise or fall), so that efficient evaporation is realized.

In the operation process of the air path subsystem, when air in the system enters the evaporation tower 5 under the action of the circulating fan 9, the air is in a state of high temperature and low relative humidity, passes through the surface of the titanium tube of the condenser 3 from bottom to top, takes away water vapor generated by heat absorption of wastewater, absorbs part of surface heat of the titanium tube condenser, and the temperature of the circulating air rises and the relative humidity also rises at the moment; the circulating air is conveyed by a heat preservation air pipeline, enters a primary heat recoverer 6, performs total heat exchange with the circulating air with low temperature and high relative humidity from an evaporator 5 in the heat pump subsystem, reduces the temperature and increases the relative humidity, and separates out partial condensed water; then flows through the surface of the secondary heat recoverer 7, the temperature is further reduced, the relative humidity is further increased, and partial condensed water is separated out; then flows through the evaporator 10 in the heat pump subsystem, passes through the surface of the evaporator with lower temperature, releases heat (including latent heat and sensible heat) in the water vapor to the refrigerant in the evaporator 10, the temperature is greatly reduced, the relative humidity is greatly increased, and a large amount of condensed water is separated out; the low-temperature low-humidity air discharged from the evaporator 10 of the heat pump subsystem is conveyed to the primary heat recoverer 6 through the air pipe, is subjected to full heat exchange with the high-temperature high-humidity air from the evaporation tower 5, is subjected to temperature rise and relative humidity fall to form drier hot air, passes through the air pipe again, enters the evaporation tower 5, and takes away heat and water vapor on the surface of the titanium pipe of the condenser 3 in cycles. In the process, the stable operation of the whole system is realized through the changes of the temperature and the relative humidity of the circulating air, and condensed water is separated out, so that the aim of desalting the wastewater containing high salt and high COD to separate out pure water is fulfilled. In the working process of the whole air circulation system, air in the system is isolated from the outside (all air pipes wrap the heat insulation layer), is not mixed with air outside the system, and only carries out moderate and controlled heat exchange (in the secondary heat recoverer, the heat exchange is carried out by external cooling water), so that the operation of the whole system is stable and measurable.

The purpose of heat balance (unloading) is to unload the accumulated heat of the whole system, so that the whole system achieves the purpose of heat balance. The utility model relates to a circulation system is a closed system, neglecting under the condition of entire system to external environment's heat loss, the absorptive heat of waste water evaporation should equal the heat of condensate water release, heat pump subsystem's compressor unit 12 constantly consumes the electric energy, therefore entire system's heat is "forward" accumulation, in order to maintain the heat balance of system, sustainable operation, when heat accumulation to certain extent, must unload this part of heat of this part accumulation, with this part of unnecessary heat that the balance fell in the inside unable consumption of system, make the temperature in the evaporating tower 5 keep at a stable state. The process of heat unloading is to automatically judge whether to start operation or not and the operation time according to the temperature of the evaporation tower. The cooling water with lower temperature from the outside of the system (such as a cooling tower) enters the secondary heat recoverer 7 according to the requirement, and takes away the redundant heat in the system.

The throttling element 11 of the heat pump subsystem adopts an electronic expansion valve, and the opening degree of the expansion valve is adjusted in real time, so that the proper refrigerant flow at different waste water temperatures can be accurately controlled, and the efficient and stable operation of the whole heat pump subsystem is realized.

The closed circulation evaporation and condensation system for treating the high-salt and high-COD wastewater provided by the utility model has the advantages of normal pressure evaporation and medium and low temperature evaporation; high-efficiency evaporation, energy-saving evaporation and stable evaporation. Specifically, the method comprises the following steps: three heat-carrying media of water, air and refrigerant are utilized; two carrier media of water and air are utilized; the heat-carrying medium and the carrier medium are synchronously circulated in parallel, so that the heat transfer and the mass transfer are synchronous; closed self-circulation evaporation and condensation technology; the heat recovery technology of air and refrigerant double-path is adopted, and the heat in the heat-carrying medium is recovered to the maximum extent; cooling at an air circulation condensation end to ensure heat balance of the heat pump system under a closed circulation working condition; the water evaporation technology at normal pressure and medium and low temperature (less than or equal to 55 ℃) is adopted, so that the problems of scaling, organic matter coking and blocking and the like are effectively avoided; at the air circulation condensation end, the three-temperature zone is adopted for cooling, so that the water outlet efficiency of the condensed water is greatly improved.

The above only is the embodiment of the present invention, not limiting the scope of the present invention, all the equivalent structures or equivalent processes of the present invention are used in the specification and the attached drawings, or directly or indirectly applied to other related technical fields, and the same principle is included in the protection scope of the present invention.

Claims

1. A closed circulation evaporation and condensation system for containing high salt high COD waste water treatment, which is characterized by comprising:

a wastewater tank;

one end of the waste water pump is connected with the waste water tank;

the evaporation tower is arranged on one side of the wastewater trough;

a condenser disposed within the evaporation tower;

the spray pipe is arranged in the evaporation tower, is connected with the waste water pump and is positioned above the condenser;

the primary heat recoverer is connected with the evaporation tower;

the secondary heat recoverer is connected with the primary heat recoverer;

the condensation tower is connected with the secondary heat recoverer and the primary heat recoverer;

the circulating fan is arranged in the condensing tower;

the evaporator is arranged in the condensation tower and is positioned below the circulating fan;

the throttling element is respectively connected with the condenser and the evaporator;

the inlet and the outlet of the compressor unit are respectively connected with the condenser and the evaporator;

and the concentrated liquid pump is connected with the evaporation tower and the wastewater tank.

2. The closed circulation evaporation and condensation system for the treatment of wastewater with high salt content and high COD according to claim 1, characterized in that the top and one side of the evaporation tower are provided with connecting pipes, and both connecting pipes are connected with the primary heat recoverer.

3. The closed circulation evaporation and condensation system for the treatment of wastewater with high salt content and high COD according to claim 1, wherein the condenser is installed at the middle position inside the evaporation tower, the spray pipe is installed at the upper part of the condenser, and the spray pipe and the condenser are arranged in parallel and staggered layers.

4. The closed cycle evaporative condensation system for treating wastewater with high salt and high COD according to claim 1, is characterized in that three substances of water, air and refrigerant are used as circulating heat carrying media of the system; two substances, namely water and air, are used as circulating carrier media of the system, and the heat-carrying media and the carrier media are synchronously circulated in parallel in the system, so that the synchronous operation of heat transfer and mass transfer is realized.

5. The closed cycle evaporative condensation system for treating wastewater containing high salt and high COD according to claim 1, wherein the system adopts closed self-circulation evaporation and condensation technology, the evaporation of wastewater and the condensation of purified water are respectively carried out simultaneously in the closed system, and the energy is recycled at the evaporation end and the condensation end under the support of the air path circulation and the refrigerant circulation.

6. The closed cycle evaporative condensation system for treating wastewater containing high salt and high COD according to claim 1, characterized in that the system adopts air and refrigerant two-way heat recovery technology to recover the heat in the heat-carrying medium to the maximum extent; and the temperature is reduced at the air circulation condensation end, so that the heat balance of the heat pump system under the closed circulation working condition is ensured.

7. The closed circulation evaporation and condensation system for treating high-salt and high-COD wastewater according to claim 1, characterized in that the system adopts a water evaporation technology under normal pressure and medium and low temperature conditions, so as to effectively avoid the problems of scaling and organic matter coking blockage caused by the treatment of high-salt and high-COD wastewater.

8. The closed cycle evaporative condensation system for treating wastewater containing high salt and high COD according to claim 1, wherein the system is used for gradually and gradiently cooling the high-temperature high-humidity circulating air in three different temperature areas of a primary heat recovery device, a secondary heat recovery device and an evaporator at the condensation end of the air cycle, so as to improve the water outlet efficiency of condensed water.

9. The closed cycle evaporative condensation system for treating wastewater containing high salt and high COD according to claim 1, wherein the evaporation and condensation of water in the system are evaporation and condensation in a closed cycle state, the heat absorbed by evaporation and the heat released by condensation are balanced, the system is heated in the form of electric energy input, but in order to drive the heat in the heat-carrying medium to carry out cycle 'carrying' at the evaporation and condensation ends, certain external energy must be consumed, the external energy must do work to generate certain excess heat, when the heat is accumulated to a certain degree, the accumulated heat must be discharged out of the system, and therefore, an external cold source is used to realize the heat balance inside the system.