CN211946534U

CN211946534U - Coal gasification black ash water energy recovery and fly ash recycling system

Info

Publication number: CN211946534U
Application number: CN202020430320.1U
Authority: CN
Inventors: 张志军; 张志超
Original assignee: Shijiazhuang Beot Inorganic Membrane Separating Device Co ltd
Current assignee: Shijiazhuang Beot Inorganic Membrane Separating Device Co ltd
Priority date: 2020-03-30
Filing date: 2020-03-30
Publication date: 2020-11-17
Anticipated expiration: 2030-03-30

Abstract

The utility model provides a coal gasification black ash water energy recovery and fly ash recycling system, which belongs to the technical field of coal gasification, and comprises a separation device, a lock hopper, a clear liquid storage tank and a thick slurry recovery processing device, wherein the separation device comprises a shell, a filtering unit arranged inside the shell and a back flush pipeline arranged outside the shell; the shell is provided with an inlet pipeline for introducing black ash water and a compensating liquid pipeline for introducing compensating liquid; the lock hopper is communicated with the shell; the clear filtrate storage tank is communicated with the open end of the discharge pipe outside the shell, and the first outlet is communicated with the back flush pipeline; and the dense slurry recovery processing device is communicated with the lock hopper. The utility model provides a coal gasification black ash water energy recovery and fly ash system of recycling replaces processes such as flash distillation among the prior art, removes ash and retrieves and recycles the fly ash sediment under the black ash water does not step down the cooling condition, retrencies process flow, reduces the energy consumption, reduces area, reduces the investment.

Description

Coal gasification black ash water energy recovery and fly ash recycling system

Technical Field

The utility model belongs to the technical field of coal gasification, more specifically say, relate to coal gasification black ash water energy recovery and fly ash system of recycling.

Background

Coal is used as one of three petrochemical energy sources in China, and is mainly applied to important fields of civil fuel, power generation, chemical industry, industrial fuel and the like. The basic characteristics of energy sources in China are that coal is rich in coal, oil and gas, and coal is used as an important fuel and a chemical raw material to play an extremely important role in the development process of national economy in China.

Coal gasification refers to a process in which organic matters in coal and a gasifying agent (such as steam, air or oxygen) undergo a series of chemical reactions at a certain temperature and pressure in specific equipment (such as a fly ash gasifier) to convert solid coal into combustible gas containing CO, H2, CH4 and the like and non-combustible gas containing CO2 and the like. The gas generated by coal gasification is mainly used for industrial fuel, civil fuel, chemical synthesis, metallurgical reducing gas, combined cycle power generation fuel gas, coal gasification fuel cells, coal gasification hydrogen production, coal liquefaction gas source and the like.

The coal gasification technology in the field of coal chemical industry mainly adopts entrained flow bed gasification technology, which typically represents coal water slurry gasification technology and pulverized coal gasification technology; both the two processes relate to a water chilling process, and aim to cool the raw synthesis gas by water and remove ash in the raw synthesis gas, so that the raw synthesis gas reaches a certain temperature and cleanliness when going to subsequent processes. A large amount of high-temperature and high-pressure (the temperature is 150-; and the black grey water is returned to the coal powder gasification furnace for recycling after being treated, and the black grey water is treated to remove ash in the black grey water in the system.

At the present stage, the traditional black grey water treatment method is that high-temperature and high-pressure black grey water discharged from a fly ash gasification furnace enters a settling tank after three-stage flash evaporation (the three-stage flash evaporation process is high-pressure flash evaporation, low-pressure flash evaporation and vacuum flash evaporation), a flocculating agent is added into the settling tank to enable black grey water to be layered, the fly ash mortar of turbid liquid at the lower layer is discharged as waste, and supernatant (hereinafter referred to as grey water) enters an ash water tank; the grey water is pumped out from the grey water tank by a pump, and the grey water can enter the fly ash gasification furnace for recycling after being reheated by steam generated by flash evaporation.

The traditional black grey water treatment process has the following defects:

1) the energy consumption is high. Multi-stage flash evaporation causes heat energy loss;

2) the resources are wasted. The direct discharge of the fly ash mortar not only pollutes the environment, but also wastes resources.

3) Large occupied area and large investment. The high-temperature black and gray water can be cooled only by multi-stage flash evaporation, so that the number of equipment is increased; the system flow is long, so that the investment of purchasing and construction costs of pipelines, instruments, civil engineering and the like is increased;

4) the process is unstable, abnormal shutdown occurs, long-period operation of the gasification furnace is influenced, and the inspection and maintenance are frequent. In the multi-stage flash process of the high-temperature black grey water, dissolved salts are separated out due to temperature reduction and escape of acid gas, so that subsequent equipment is scaled, and long-period operation of the equipment is influenced.

SUMMERY OF THE UTILITY MODEL

Based on the technical problem, the utility model provides a coal gasification black ash hydroenergy retrieves and fly ash system of recycling, it can reduce calorific loss, improves water resource utilization, realizes that the fly ash mortar retrieves and recycles, reduces area, reduces the investment, reduces and examines the maintenance number of times.

The utility model provides a coal gasification black grey water energy recovery and fly ash system of recycling, wherein, coal gasification black grey water energy recovery and fly ash system of recycling includes:

the separation device comprises a shell, a filtering unit arranged in the shell and a backwashing pipeline arranged outside the shell; an inlet pipeline for introducing black ash water and a compensating liquid pipeline for introducing compensating liquid are arranged on the shell;

the filter unit comprises a plurality of filter elements, the upper ends of the filter elements are connected in parallel and communicated with a drain pipe, the open end of the drain pipe extends to the outside of the shell, the drain pipe is connected in parallel and communicated with the backwashing pipeline, the filter elements are used for filtering black ash water and separating out coal ash slurry and clear filtrate, the drain pipe is used for discharging the clear filtrate, and the coal ash slurry is retained in the shell;

the lock hopper is communicated with the shell and is used for collecting the pulverized coal slurry;

the filtered liquid storage tank is communicated with the opening end of the calandria and is used for collecting filtered liquid; the filter liquor storage tank is also provided with a first outlet and a second outlet, the first outlet is used for being communicated with the backwashing pipeline, and the second outlet is used for being communicated with the fly ash gasification furnace;

and the thick slurry recovery processing device is communicated with the lock hopper and is used for processing and recovering the fly ash slurry.

In the coal gasification black ash water energy recovery and fly ash recycling system, preferably, the black ash water inlet pipeline and the compensating liquid pipeline are connected in parallel.

In the coal gasification black ash water energy recovery and fly ash recycling system, preferably, the discharge pipe is provided with a first valve, and the back flush pipeline is provided with a second valve.

In the coal gasification black ash water energy recovery and fly ash recycling system, preferably, a third valve is arranged between the shell and the lock hopper, and the lock hopper is also provided with a pressure relief opening.

In the coal gasification black grey water energy recovery and fly ash recycling system, preferably, the system further comprises a pressurizing pipeline, wherein the pressurizing pipeline is communicated with the lock hopper and is used for injecting the black grey water into the lock hopper.

In the coal gasification black ash water energy recovery and fly ash recycling system, preferably, the concentrated slurry recovery treatment device comprises a solid-liquid separation unit and a drying unit, wherein the solid-liquid separation unit is communicated with the lock hopper and is used for dehumidifying the fly ash slurry; the drying unit is connected with the solid-liquid separation unit and used for drying the coal-powder mortar.

In the coal gasification black ash water energy recovery and fly ash recycling system, preferably, the dense slurry recovery processing device further comprises a transfer unit, and the transfer unit is connected with the lock hopper and used for storing the fly ash slurry; the transfer unit is also connected with the solid-liquid separation unit and is used for injecting the fly ash slurry into the solid-liquid separation unit.

In the coal gasification black ash water energy recovery and fly ash recycling system, preferably, the solid-liquid separation unit is one or a combination of a centrifuge, a frame plate filter press, a horizontal filter, a vacuum drum filter or a lamination filter.

In the coal gasification black ash water energy recovery and fly ash recycling system, preferably, the system further comprises a cleaning liquid tank for storing a cleaning liquid, the cleaning liquid tank is further provided with a first pipeline and a second pipeline, the first pipeline is communicated with the housing and used for injecting the cleaning liquid into the housing, and the second pipeline is communicated with the housing and used for returning the cleaned liquid to the cleaning liquid tank.

The filter element material can be sintered metal powder microporous material, sintered metal multilayer wire mesh material, sintered metal felt material or wound wedge wire tube material.

The utility model provides a coal gasification black ash water energy recovery and fly ash system of recycling has reduced black ash water treatment process, has abandoned the investment of equipment such as black ash water needs flash distillation, condensation, compared with the prior art, the utility model discloses black ash water treatment process is simple, has not only saved scale deposit, has corroded serious flash distillation process, reduces area, reduces the investment, and black ash water need not cool down the processing simultaneously, has fully improved heat utilization ratio; the coal-dust mortar obtained after the black ash water is filtered is recycled by a thick slurry recovery processing device, so that the economic cost is reduced, and the resources are saved; the compensation liquid in the compensation liquid pipeline can prevent the evaporation of the black ash water, thereby avoiding the large-area scaling inside the separation device, prolonging the service life of the equipment, prolonging the operation period of the system and reducing the maintenance times. Compared with the prior art, the utility model discloses well filtrate liquid remains high temperature high pressure throughout, does not have heat energy loss for a part that returns the fly ash gasifier filters the liquid and need not earlier through the steam reheat that the flash distillation produced, just can directly get into fly ash gasifier circulation and recycle, and another part filters the liquid and can be used to separator's backwash liquid, both improves water resource utilization and rate, improves heat utilization again.

Drawings

FIG. 1 is a schematic diagram of the connection relationship of a coal gasification black ash water energy recovery and fly ash recycling system provided by an embodiment of the present invention;

in the figure: 1. a housing; 2. back flushing the pipeline; 3. a black ash water inlet line; 4. a compensation fluid pipeline; 5. a filter element; 6. arranging pipes; 7. locking the bucket; 8. a filtered liquid storage tank; 9. a dense slurry recovery processing device; 10. a first valve; 11. a second valve; 12. a third valve; 13. a pressure relief port; 14. a pressurization pipeline; 15. a solid-liquid separation unit; 16. a drying unit; 17. a transfer unit; 18. cleaning a liquid tank; 19. a first pipeline; 20. a second pipeline; 21. a first booster pump; 22. a second booster pump; 23. a third booster pump; 24. black grey water; 25. low-temperature and low-pressure water; 26. filtering the solution; 27. a fourth valve; 28. a fifth valve; 29. a sixth valve; 30. a seventh valve; 31. an eighth valve; 32. a ninth valve; 33. a tenth valve; 34. an eleventh valve; 35. a twelfth valve; 36. a thirteenth valve; 37. a fourteenth valve; 38. a fifteenth valve.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

Fig. 1 is a schematic diagram of a connection relationship between coal gasification black ash water energy recovery and fly ash recycling systems provided by an embodiment of the present invention.

As shown in fig. 1, an embodiment of the present invention provides a coal gasification black ash water energy recovery and fly ash recycling system, and a separation device, where the separation device includes a housing 1, a filtering unit disposed inside the housing 1, and a back-washing pipeline 2 disposed outside the housing 1; an inlet pipeline 3 for introducing black grey water 24 and a compensating liquid pipeline 4 for introducing compensating liquid are arranged on the shell 1;

the filter unit comprises a plurality of filter elements 5, the upper ends of the filter elements 5 are connected in parallel and communicated with a drain pipe 6, the open end of the drain pipe 6 extends to the outside of the shell 1, the drain pipe 6 is connected in parallel and communicated with the backwashing pipeline 2, the filter elements 5 are used for filtering black grey water and separating out coal powder mortar and a filtrate 26, the drain pipe 6 is used for discharging the filtrate 26, and the coal powder mortar is reserved in the shell 1;

a lock hopper 7, wherein the lock hopper 7 is communicated with the shell 1 and is used for collecting the fly ash slurry;

a filtered liquid storage tank 8, said filtered liquid storage tank 8 being in communication with the open end of said calandria 6 for collecting filtered liquid 26; the filtrate storage tank 8 is also provided with a first outlet and a second outlet, the first outlet is used for being communicated with the backwashing pipeline 2, and the second outlet is used for being communicated with a fly ash gasification furnace;

and the thick slurry recovery processing device 9 is communicated with the lock hopper 7 and is used for processing and recovering the fly ash slurry.

Preferably, a first valve 10 is arranged on the discharge pipe, and a second valve 11 is arranged on the back-flushing pipeline. A third valve 12 is arranged between the shell 1 and the lock hopper 7, and a pressure relief opening 13 is further formed in the lock hopper 7.

Preferably, the device further comprises a pressurization pipeline 14, wherein the pressurization pipeline 14 is communicated with the lock hopper 7 and is used for injecting the black grey water into the lock hopper 7. The lock hopper 7 can be pressurized and heated by utilizing the high temperature and the high pressure of the black ash water, so that the energy utilization rate is improved, and the high efficiency and the high speed are realized.

Preferably, the concentrated slurry recovery processing device 9 comprises a solid-liquid separation unit 15 and a drying unit 16, wherein the solid-liquid separation unit 15 is communicated with the lock hopper 7 and is used for separating the fly ash slurry into fly ash and liquid; the drying unit 16 is connected with the solid-liquid separation unit 15 and is used for drying the fly ash. In order to improve the recovery rate of fly ash slurry, the moisture content in fly ash can be reduced to the maximum extent by using a process of separating and then drying.

Preferably, the thick slurry recycling device 9 further comprises a transfer unit 17, wherein the transfer unit 17 is connected with the lock hopper 7 and is used for storing the fly ash slurry; the transfer unit 17 is further connected to the solid-liquid separation unit 15, and is configured to inject the fly ash slurry into the solid-liquid separation unit 15. The transfer unit 17 prolongs the production period, is equivalent to a transfer station, and is generally a tank body,

preferably, the solid-liquid separation unit 15 is one or more of a centrifuge, a frame plate filter press, a horizontal belt filter, a vacuum drum filter or a lamination filter. The separation effect of the devices is good, and the devices can be selected or combined for use according to specific working conditions.

Preferably, the cleaning device further comprises a cleaning liquid tank 18 for storing cleaning liquid, the cleaning liquid tank 18 is further provided with a first pipeline 19 and a second pipeline 20, the first pipeline 19 is communicated with the housing 1 and is used for injecting the cleaning liquid into the housing 1, and the second pipeline 20 is communicated with the housing 1 and is used for returning the cleaned liquid to the cleaning liquid tank 18. Other valves are respectively disposed on the corresponding pipelines, and specific correspondence can refer to fig. 1, which is not described again.

The material of the filter element 5 can be any one of sintered metal powder microporous material, sintered metal multilayer wire mesh material, sintered metal felt material or wound wedge-shaped wire tube material, and the material suitable for the working condition can be selected according to the actual situation on site.

As shown in fig. 1, the coal gasification black ash water energy recovery and fly ash recycling system provided by the embodiment of the present invention adopts the following main devices:

the separation device here is a high-pressure separation device: one or more than one filter element are connected in parallel, and a conventional sintering filter element is selected in the separation device, so that the full-automatic filtration and back-washing functions are realized; the separation device can also be a suspension (cyclone) separator, which belongs to the prior art;

the lock hopper 7, the filtrate tank 8, and the thick slurry recovery processing device 9 are well-known devices, and are known to those skilled in the art.

The connection relationship is as follows:

black ash water 24 from the fly ash gasification furnace enters the separation device through the black ash water inlet pipeline 3, the sixth valve 29 controls the flow of the black ash water, meanwhile, compensation liquid is discharged into the separation device through the compensation liquid pipeline 4, and the seventh valve 30 controls the flow of the compensation liquid. If high temperature high pressure black grey water directly emits into separator, the great evaporation that appears of black grey water cooling, appear that the dissolved salts in the black grey water is separated out and is caused follow-up equipment scale deposit phenomenon, in order to avoid above-mentioned condition to take place, this embodiment adopts the method to be: the black grey water inlet line 3 and the compensating liquid line 4 are in parallel, i.e. the black grey water 24 and the compensating liquid are mixed before they enter the separating device.

After entering the separation device, the black ash water 24 enters the interior of the filter element 5 from the outside, and ash with a certain particle size is blocked on the outer wall of the filter element 5 through the filter element 5 (the particle size of the filtered ash of the filter element 5 can be realized by selecting the filtering precision of the filter element 5 according to the actual needs on site); the liquid entering the filter element 5 is the filtrate 26; the filtered liquid 26 enters the filtered liquid storage tank 8 through the discharge pipe 6, and a connecting pipeline with a flange can be arranged between the discharge pipe 6 and the filtered liquid storage tank 8 for convenient installation, maintenance and disassembly; a small part of the filtered liquid 26 in the filtered liquid storage tank 8 reaches the inside of the filter element 5 through the backwashing pipeline 2 for backwashing, at this time, the fourth valve 27 is in a closed state, it should be noted that the backwashing pipeline 2 is provided with the first booster pump 21, and a large part of the filtered liquid 26 in the filtered liquid storage tank 8 is discharged into the fly ash gasification furnace (not shown in fig. 1) through the second booster pump 22 for recycling; the single separation device can simultaneously carry out filtering and backwashing operations, a first valve 10 is arranged on the discharge pipe 6, a second valve 11 is arranged on the backwashing pipeline 2, and the functions are realized by switching the opening or closing of the first valve 10 and the second valve 11, so that the economic cost and the occupied area are saved; of course, according to actual production needs, the number of the separating devices can be multiple, and multiple separating devices are connected in parallel.

Ash content blocked on the outer wall of the filter element 5 is fly ash mortar, the fly ash mortar can freely settle into the lock hopper 7 after backflushing, when the fly ash mortar in the lock hopper 7 reaches a certain amount, the third valve 12 arranged between the shell 1 and the lock hopper 7 is closed, the fly ash mortar in the shell 1 is blocked to be continuously discharged into the lock hopper 7, the pressure relief port 13 is opened to relieve pressure, then the thirteenth valve 36 is opened, and the fly ash mortar is discharged into the thick slurry recovery processing device 9 for subsequent processing; when the pulverized coal mortar in the lock hopper 7 is completely discharged and needs to be communicated with the shell 1 again, closing a thirteenth valve 36, opening a twelfth valve 35, firstly discharging low-temperature low-pressure water 25 from the pressurization pipeline 14 to fill the lock hopper 7, stopping discharging the low-temperature low-pressure water 25 into the lock hopper 7 after the low-temperature low-pressure water 25 reaches a specified liquid level, and then discharging black grey water 24 into the lock hopper 7, so that the high-temperature high-pressure of the black grey water 24 is used for increasing the temperature and pressurizing of the lock hopper 7, when the pressure in the lock hopper 7 reaches the required pressure, opening a third valve 12 to be communicated with the shell 1 again, and thus, cyclically discharging the pulverized coal mortar into the lock hopper 7;

the fly ash slurry discharged into the thick slurry recycling device 9 sequentially passes through a solid-liquid separation unit 15 and a drying unit 16, the solid-liquid separation unit 15 is communicated with a lock hopper 7 and is used for separating fly ash from liquid, wherein the solid-liquid separation unit 15 can be one or a combination of a centrifugal machine, a frame plate filter press, a horizontal belt filter, a vacuum drum filter or a lamination filter, and is specifically determined according to the actual situation on site; the drying unit 16 is connected to the solid-liquid separation unit 15, and when the fly ash in the solid-liquid separation unit 15 is dried, the fifteenth valve 38 is opened to perform the drying operation. In order to realize the continuity of the above operations and improve the working efficiency, a transfer unit 17 needs to be additionally arranged between the lock hopper 7 and the solid-liquid separation unit 15, the transfer unit 17 is respectively connected with the lock hopper 7 and the solid-liquid separation unit 15 through pipelines, and a thirteenth valve 36 and a fourteenth valve 37 are respectively arranged on the respective connecting pipelines, so that the operation is convenient.

It should be noted that, when the housing 1 needs to be completely chemically cleaned, the first valve 10, the third valve 12, the eighth valve 31 and the eleventh valve 34 need to be closed, and the fifth valve 28, the second valve 11 and the fourth valve 27 need to be opened, respectively, so that a loop for circulating the cleaning liquid is formed between the cleaning liquid tank 18 and the housing 1, and the cleaning liquid is discharged into the housing 1 through the third pressurizing pump 23 for chemical cleaning.

The specific working process is as follows:

preparation work before filtration: opening the seventh valve 30, the third valve 12, the first valve 10 and the twelfth valve 35, and filling the lock hopper 7, the shell 1 and the filtrate storage tank 8 with the low-temperature and low-pressure water 25 in sequence through the pressurization pipeline 14;

and (3) a system pressurization process: opening a sixth valve 29, and discharging the black ash water 24 into the lock hopper 7, the shell 1 and the filtered liquid storage tank 8 in sequence through the pressurization pipeline 14 to pressurize the whole system;

black grey water 24 continuous filtration: opening a sixth valve 29, discharging black ash water 24 into the black ash water inlet pipeline 3, and simultaneously discharging low-temperature low-pressure water 25 into the compensating liquid pipeline 4, so that the black ash water 24 and the low-temperature low-pressure water 25 are mixed according to a certain proportion and then discharged into the inner cavity of the shell 1; when the pressure in the shell 1 and the lock hopper 7 gradually rises, the calandria 6 starts to discharge the high-pressure and high-temperature filtered liquid 26, and the filtered liquid 26 is discharged into the filtered liquid storage tank 8; the filtrate 26 in the filtrate storage tank 8 is divided into two purposes, one is used for returning to the pulverized coal gasification furnace in the former process for recycling, and continuous filtration is realized under the condition of no pressure loss and no temperature loss; the other is used as grouped backwashing regeneration liquid, and the backwashing regeneration operation is carried out from the interior of the filter element 5 through the backwashing pipeline 2 at regular intervals, and the specific operation method is as follows: the eleventh valve 34, the third valve 12, the fourth valve 27 and the first valve 10 are closed, the second valve 11 and the eighth valve 31 are opened, and a part of the filtrate 26 is pumped into the discharge pipe 6 by the first booster pump 21, so that the regular backwashing regeneration operation of the inside of the filter element 5 is realized.

Periodically closing the lock hopper 7, and discharging pulverized coal slurry by pressure relief: after the operation is carried out for a certain time, namely when the content of the pulverized coal mortar in the lock hopper 7 is high, the third valve 12 is closed, the pressure relief operation is carried out through the pressure relief opening 13, after the pressure relief is completed, the thirteenth valve 36 is opened, the low-pressure low-temperature water 25 is discharged into the lock hopper 7, and the backwashing operation is carried out on the pulverized coal mortar in the lock hopper 7, so that the pulverized coal mortar in the lock hopper 7 is quickly and efficiently discharged to the transfer unit 17, and the solid content of the discharged pulverized coal mortar is about 30-40%; closing the thirteenth valve 36, discharging the low-temperature low-pressure water 25 into the lock hopper 7 through the pressurization pipeline 14 for replenishing, and closing the seventh valve 30 when the lock hopper 7 is full of the low-temperature low-pressure water 25; the sixth valve 29 is opened, the black grey water 24 is introduced into the lock hopper 7 for pressurization, and after the set pressure value is reached, the third valve 12 is opened, the communication with the housing 1 is resumed, and the discharge of the fly ash slurry into the lock hopper 7 is resumed.

And (3) recycling the fly ash slurry: discharging the fly ash slurry in the transfer unit 17 into a solid-liquid separation unit 15, performing solid-liquid separation on the fly ash slurry to obtain fly ash and liquid, and directly discharging the liquid or treating the liquid according to actual conditions on site; through detection, if the carbon content of the fly ash is about 20-30%, the fly ash can be directly used for the fluidized bed boiler or the pulverized coal boiler to be co-fired with coal, if the carbon content of the fly ash is less than 20%, drying treatment is needed, namely, the fly ash with the carbon content of less than 20% is discharged into a drying unit 16 to be dried, and after the moisture content in the fly ash is further reduced, the carbon content of the fly ash is detected to be about 20-30%, and then the fly ash is used for the fluidized bed boiler or the pulverized coal boiler to be co-fired with coal. The fly ash has other purposes, such as being used for refilling toilets, and has light weight, easy tamping and smell absorption, thereby effectively solving the problem of peculiar smell in the toilets. The coal-ash slurry is treated to obtain the carbon slag which can be reused, and the carbon slag can be reused as a secondary material, is beneficial to environmental protection, reduces economic cost, improves energy utilization rate, and realizes energy recovery and reuse; in the black ash water treatment process in the prior art, the fly ash slurry is directly treated as garbage.

And (3) periodically carrying out chemical cleaning operation: and after the set pressure difference value is reached, closing the sixth valve 29 and the seventh valve 30, stopping discharging the black grey water 24 and the low-temperature low-pressure water 25 into the shell 1, after the shell 1 is depressurized and emptied, closing the first valve 10, the third valve 12, the eighth valve 31 and the eleventh valve 34, and respectively opening the fifth valve 28, the second valve 11 and the fourth valve 27, so that a loop for circulating the cleaning liquid is formed between the cleaning liquid tank 18 and the shell 1, discharging the cleaning liquid into the shell 1 through the third booster pump 23 for off-line chemical cleaning, and returning the cleaned cleaning liquid to the cleaning liquid tank 18 for recycling.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention.

Claims

1. Coal gasification black ash water energy recovery and fly ash system of recycling, its characterized in that includes:

the separation device comprises a shell, a filtering unit arranged in the shell and a backwashing pipeline arranged outside the shell; the shell is provided with a black ash water inlet pipeline for introducing black ash water and a compensating liquid pipeline for introducing compensating liquid;

2. The coal gasification black ash water energy recovery and fly ash recycling system of claim 1, wherein the black ash water inlet pipeline and the compensating liquid pipeline are connected in parallel.

3. The coal gasification black ash water energy recovery and fly ash recycling system according to claim 1, wherein a first valve is disposed on the discharge pipe, and a second valve is disposed on the backwashing pipeline.

4. The coal gasification black ash water energy recovery and fly ash recycling system according to claim 1, wherein a third valve is arranged between the housing and the lock hopper, and a pressure relief opening is further arranged on the lock hopper.

5. The coal gasification black grey water energy recovery and fly ash recycling system of claim 4, further comprising a pressurization pipeline, wherein the pressurization pipeline is communicated with the lock hopper and is used for injecting the black grey water into the lock hopper.

6. The coal gasification black ash water energy recovery and fly ash recycling system according to claim 1, wherein the thick slurry recovery processing device comprises a solid-liquid separation unit and a drying unit, wherein the solid-liquid separation unit is communicated with the lock hopper and is used for separating the coal ash slurry into fly ash and liquid; and the drying unit is connected with the solid-liquid separation unit and is used for drying the fly ash.

7. The coal gasification black ash water energy recovery and fly ash recycling system according to claim 6, wherein the thick slurry recovery processing device further comprises a transfer unit, the transfer unit is connected with the lock hopper and used for storing the fly ash slurry; the transfer unit is also connected with the solid-liquid separation unit and is used for injecting the fly ash slurry into the solid-liquid separation unit.

8. The coal gasification black ash water energy recovery and fly ash recycling system of claim 6, wherein the solid-liquid separation unit is one or more of a centrifuge, a frame plate filter press, a horizontal belt filter, a vacuum drum filter or a lamination filter.

9. The coal gasification black ash water energy recovery and fly ash recycling system according to claim 8, further comprising a cleaning liquid tank for storing a cleaning liquid, wherein the cleaning liquid tank is further provided with a first pipeline and a second pipeline, the first pipeline is communicated with the housing for injecting the cleaning liquid into the housing, and the second pipeline is communicated with the housing for returning the cleaned liquid to the cleaning liquid tank.

10. The coal gasification black ash water energy recovery and fly ash recycling system of any one of claims 1 to 9, wherein the filter element material is a sintered metal powder microporous material, a sintered metal multi-layer wire mesh material, a sintered metal felt material, or a wound wedge wire tube material.