Treatment and energy recovery system for high-solid-content black water

Abstract

The utility model provides a high-solid-content black water treatment and energy recovery system, and belongs to the field of wastewater filtration. According to the utility model, the tubular automatic backwashing filter is used for filtering the black water in the gasification furnace, so that the blockage and abrasion of other equipment are reduced, the filtering efficiency is improved, the problem that the energy of the black water with overhigh solid content cannot be recycled is solved, the recycled electric energy can be reused, the energy is saved, the energy consumption is reduced, and the production cost is reduced. Filtered filtrate is introduced into the hydraulic turbine equipment, pressure energy of the filtrate is recycled, heat of the filtrate flowing out of the hydraulic turbine equipment is recycled again through the heat exchanger, cold fluid is heated by the recycled heat energy, and redundant energy consumption is saved.

Description

Technical Field

[0001] The utility model belongs to the field of wastewater filtration, and particularly relates to a treatment and energy recovery system for high-solid-content black water. Background Technique

[0002] A large amount of black water is generated during the coal gasification process. The solid content in the black water is extremely high. The traditional treatment method for such black water is only to carry out solid-liquid separation and then treat and discharge the waste liquid and waste solids. However, the energy consumption during the treatment process is relatively high, and the temperature and energy of such black water are also relatively high, resulting in a large amount of energy being wasted during the coal gasification process and increasing the energy consumption of subsequent emissions and treatment. Therefore, with the development of the coal gasification field, the energy of the black water generated by coal gasification is gradually utilized.

[0003] CN113461186A discloses a coal gasification black ash water energy recovery and fly ash reuse system and method. The coal gasification black ash water energy recovery and fly ash reuse system includes a separation device, a lock hopper, a clarified liquid storage tank, and a thick slurry recovery and treatment device. The separation device includes a housing, a filtration unit disposed inside the housing, and a backwashing pipeline disposed outside the housing; an inlet pipeline for introducing black ash water and a compensation liquid pipeline for introducing compensation liquid are provided on the housing; the lock hopper is communicated with the housing; a clarified liquid storage tank, the clarified liquid storage tank is communicated with the open end of the discharge pipe outside the housing, and the first outlet is used for communicating with the backwashing pipeline; a thick slurry recovery and treatment device, which is communicated with the lock hopper.

[0004] CN210393787U discloses a coal gasification black water vacuum flash steam low-temperature waste heat energy recovery device, which includes a low-pressure flash evaporator. The gas-phase outlet at the top of the low-pressure flash evaporator is connected to a low-pressure condenser, and the liquid-phase outlet at the bottom of the low-pressure flash evaporator is connected to a vacuum flash evaporator. The liquid-phase outlet of the vacuum flash evaporator is connected to a clarification tank. The gas-phase outlet of the vacuum flash evaporator is sequentially connected to the inlet of a vacuum flash separator through a first pressure transmitter, a first temperature transmitter, a first three-way joint, a flow regulating valve, the shell side of an evaporator, a first valve, and a second three-way joint. The outlet of the vacuum flash separator is connected to a subsequent process through a vacuum pump; a second regulating valve and a vacuum flash condenser are provided between the third end of the first three-way joint and the third end of the second three-way joint; the tube side of the evaporator is connected to an energy recovery unit of the black water vacuum flash steam. It has the advantages of being able to make full use of a large amount of low-temperature waste heat generated during the black water flash evaporation process, reducing the system energy consumption, realizing the comprehensive utilization of resources, and improving economic benefits.

[0005] CN207828040U discloses a slag and ash water treatment system, which includes: a traditional slag and ash water treatment system for recycling black water output from a gasification and synthesis gas washing system; a hydraulic turbine system connected between the gasification and synthesis gas washing system and the traditional slag and ash water treatment system, for recycling the pressure energy of the black water, converting the pressure energy of the black water into kinetic energy to transport the process water recycled by the traditional slag and ash water system back to the gasification and synthesis gas washing system for recycling. However, due to the high solid content in the slag produced in the coal chemical process, the use effect and life of the hydraulic turbine equipment will be greatly reduced, and it cannot operate for a long time.

[0006] To sum up, the black water generated in the coal chemical production process has a high temperature and a certain amount of energy. In the process of black water treatment, conventional treatment methods require high energy consumption, and the energy of the black water itself is wasted. In the process of black water energy recovery, due to the high solid content of black water, the wear rate of the recovery equipment increases and the maintenance cost increases, which is still a problem that needs to be solved urgently. Utility Model Content

[0007] In view of the above problems, the utility model provides a high-solid content black water treatment and energy recovery system. The system filters the black water and then recovers the energy of the filtered black water. The equipment loss in the energy recovery process is low, the required energy consumption is low, and the recovered black water has high energy, saving a lot of electricity and water resources.

[0008] The utility model provides a high-solid content black water treatment and energy recovery system, the system comprises a gasification system, a filtration system and an energy recovery system in sequence according to the flow direction of the black water;

[0009] The gasification system includes a gasifier;

[0010] The filtration system includes a tubular automatic backwash filter and a slag water recovery device;

[0011] The energy recovery system includes a hydraulic turbine device and a heat exchanger;

[0012] The slag water recovery device is connected to the tubular automatic backwash filter and the heat exchanger at the same time;

[0013] The gasifier provides the black water to the tube-in-tube automatic backwash filter, and the black water includes liquid and solid substances.

[0014] Furthermore, the tubular automatic backwashing filter includes a double-tube filtering unit, and a backwashing main pipe, a filtrate main pipe, a slag water main pipe, and a slag discharging main pipe that are arranged in sequence from top to bottom. The double-tube filtering unit includes filtering pipes on the left and right sides, a liquid outlet and a backwashing port at the top, and a liquid inlet and a slag outlet at the bottom. The backwashing main pipe is provided with a backwashing water inlet, the filtrate main pipe is provided with a filtrate outlet, the slag water main pipe is provided with a slag water inlet, and the slag discharging main pipe is provided with a filter residue outlet.

[0015] Furthermore, the backwashing water inlet on the backwashing main pipe of the tubular automatic backwashing filter is connected to the filtrate outlet on the filtrate main pipe. The filtrate outlet on the filtrate main pipe is also connected to the energy recovery system. The filter residue outlet on the slag discharging main pipe is connected to the slag water recovery device. A valve and a pipeline pump are installed at the connection between the backwashing water inlet on the backwashing main pipe and the filtrate outlet on the filtrate main pipe.

[0016] Furthermore, flushing ports are also provided on both the backwashing main pipe and the slag discharging main pipe of the tubular automatic backwashing filter. A valve is installed on the pipeline connecting the flushing port of the backwashing main pipe and the flushing port of the slag discharging main pipe. The flushing port of the backwashing main pipe is also connected to the slag outlet of the double-tube filtering unit.

[0017] Furthermore, the slag water inlet on the slag water main pipe of the tubular automatic backwashing filter is connected to the slag outlet of the gasifier.

[0018] Furthermore, cylindrical sintered metal filter elements are installed in the filtering pipes on both the left and right sides of the double-tube filtering unit. The bottom of the sintered metal filter element is of an open structure, and the top is a sealed sieve structure. The outer wall of the sintered metal filter element is welded to the inner wall of the filtering pipe without a gap.

[0019] Furthermore, the aperture of the sintered metal filter element is 10 - 15 μm.

[0020] Furthermore, the liquid outlet at the top of the double-tube filtering unit is connected to the filtrate main pipe, and the backwashing port at the top of the double-tube filtering unit is connected to the backwashing main pipe;

[0021] The liquid inlet at the bottom of the double-tube filtering unit is connected to the slag water main pipe, and the slag outlet at the bottom of the double-tube filtering unit is connected to the slag discharging main pipe;

[0022] Valves are installed at the liquid outlet and backwashing port at the top of the double-tube filtering unit, and at the liquid inlet and slag outlet at the bottom of the double-tube filtering unit.

[0023] Further, a differential pressure gauge (PD) is connected by signal lines at the liquid inlet and outlet of the double-tube filtering unit. The differential pressure gauge (PD) is connected by a signal line to a control device, and the control device is connected by signal lines to the valves at the backwash port, liquid outlet, liquid inlet, and slag discharge port of the double-tube filtering unit to control the opening and closing of the valves at the backwash port, liquid outlet, liquid inlet, and slag discharge port of the double-tube filtering unit.

[0024] Further, when the slag discharge main pipe and the slag discharge port of the double-tube filtering unit are blocked, the valve and the pipeline pump at the connection between the backwash water inlet on the backwash main pipe and the filtrate outlet on the filtrate main pipe will be opened, and the valve connecting the flush port of the backwash main pipe and the flush port of the slag discharge main pipe will be opened. The blocked part of the slag discharge main pipe and the slag discharge port of the double-tube filtering unit will be flushed with the filtrate in the backwash main pipe.

[0025] When the blockage at the slag discharge port of the slag discharge main pipe and the double-tube filtering unit is flushed open, the valve and the pipeline pump at the connection between the backwash water inlet on the backwash main pipe and the filtrate outlet on the filtrate main pipe, and the valve on the pipeline connecting the flush port of the backwash main pipe and the flush port of the slag discharge main pipe will be closed.

[0026] Further, a detachable T-shaped filter screen is installed at the flush port on the backwash main pipe of the tubular automatic backwash filter.

[0027] Further, the aperture of the T-shaped filter screen is 10 - 15 μm.

[0028] Further, wear-resistant layer structures are provided on one side of the inner walls of the filter pipes on the left and right sides of the double-tube filtering unit, as well as the backwash main pipe, filtrate main pipe, slag water main pipe, and slag discharge main pipe.

[0029] Further, the number of the double-tube filtering units is greater than or equal to 2. When the starting differential pressure (P 启动 ) of the differential pressure gauge (PD) connected at the liquid inlet and outlet of one of the double-tube filtering units is greater than the differential pressure upper limit (P max ), the control device controls the valve at the liquid inlet and outlet of this double-tube filtering unit to close, controls the valves at the backwash port and the slag discharge port of this double-tube filtering unit to open, and opens the valve and the pipeline pump at the connection between the backwash water inlet on the backwash main pipe and the filtrate outlet on the filtrate main pipe.

[0030] When the starting differential pressure (P 启动 ) of the differential pressure gauge (PD) connected at the liquid inlet and outlet of the double-tube filtering unit is less than the differential pressure lower limit (P minWhen it is (time), the control device controls the valves at the backwash port and slag discharge port of this double-tube filtration unit to close, closes the valve and pipeline pump at the connection between the backwash water inlet on the backwash main pipe and the filtrate outlet on the filtrate main pipe, and then opens the valves at the liquid inlet and liquid outlet of this double-tube filtration unit.

[0031] Further, the start-up differential pressure (P 启动 ) of the differential pressure gauge (PD) at the liquid inlet and liquid outlet of the double-tube filtration unit = the pressure (P 进液口 ) at the liquid inlet of the double-tube filtration unit - the pressure (P 出液口 ) at the liquid outlet of the double-tube filtration unit.

[0032] Further, the liquid inlet of the hydraulic turbine equipment is connected to the filtrate outlet on the filtrate main pipe of the shell-and-tube automatic backwash filter, and the liquid outlet of the hydraulic turbine equipment is connected to the heat exchanger.

[0033] Further, the heat exchanger includes a hot fluid inlet, a hot fluid outlet, a cold fluid inlet, and a cold fluid outlet; the hot fluid inlet of the heat exchanger is connected to the liquid outlet of the hydraulic turbine equipment, and the hot fluid outlet of the heat exchanger is connected to the slag water recovery device.

[0034] Further, the hot fluid inlet of the heat exchanger is placed at the upper left of the heat exchanger, and the hot fluid outlet is placed at the lower left of the heat exchanger; the cold fluid inlet of the heat exchanger is placed at the upper right of the heat exchanger, and the cold fluid outlet is placed at the lower right of the heat exchanger.

[0035] Further, the number of the heat exchangers is 2, which are divided into a first heat exchanger and a second heat exchanger. Among them, the hot fluid inlet of the first heat exchanger is connected to the liquid outlet of the hydraulic turbine equipment; the hot fluid inlet in the second heat exchanger is connected to the liquid outlet of the hydraulic turbine equipment and also connected to the hot fluid outlet of the first heat exchanger; the hot fluid outlet of the second heat exchanger is connected to the slag water recovery device.

[0036] Further, when the temperature of the filtrate at the liquid outlet of the hydraulic turbine equipment is greater than 170 °C, the filtrate first passes through the first heat exchanger and then through the second heat exchanger;

[0037] When the temperature of the filtrate at the liquid outlet of the hydraulic turbine equipment is 100 - 170 °C, the filtrate only passes through the second heat exchanger.

[0038] Furthermore, the hot fluid in the hot fluid inlets and outlets of the first heat exchanger and the second heat exchanger is the filtrate flowing out of the liquid outlet of the hydraulic turbine equipment. The cold fluid inlet of the first heat exchanger is high-temperature boiler water, the cold fluid outlet of the first heat exchanger is saturated steam, the cold fluid inlet of the second heat exchanger is low-temperature desalted water, and the cold fluid outlet of the second heat exchanger is high-temperature desalted water.

[0039] Advantages of the present utility model:

[0040] 1. By using the tube-sheet type automatic backwashing filter to filter the black water in the gasifier, the tube-sheet type automatic backwashing filter can reduce the solid content in the black water, reduce the blockage and wear of other equipment. During the use of the tube-sheet type automatic backwashing filter, the flushing of the double-tube filtering unit can be controlled by adjusting the valve, and there are multiple parallel double-tube filtering units, so that the equipment can continue to operate when one of the double-tube filtering units is backflushing, improving the filtering efficiency, saving costs and significantly extending the operation cycle of the tube-sheet type automatic backwashing filter, and shortening the maintenance time. The tube-sheet type automatic backwashing filter in the present utility model has good heat resistance and can filter black water at different temperatures, with wide applications.

[0041] 2. The present utility model solves the problem that the energy of the black water with too high solid content cannot be recovered. The solid content removal rate of the black water reaches 70 - 95%. The filtered filtrate is introduced into the hydraulic turbine equipment to recover its pressure energy, and the recovered electric energy is 100 - 800 kWh. The recovered electric energy can be reused, saving energy and reducing energy consumption. The filtrate flowing out of the hydraulic turbine equipment is further passed through a heat exchanger for heat recovery, and the recovered heat energy is used to heat the cold fluid, saving the redundant energy consumption. During the process of using the heat exchanger for waste heat recovery, the consumption of circulating water is saved by 400 - 1200 t / h. If steam is used to heat the cold fluid, 15 - 50 t / h of saturated steam is required, which is equivalent to a carbon dioxide emission of 3000 - 10000 kg, with huge energy consumption. The present utility model utilizes the energy of the black water in the system, which not only saves resources but also recovers the energy of the black water. Description of the drawings

[0042] Figure 1 It is a schematic structural diagram of the high-solid-content black water treatment and energy recovery system in Embodiment 1;

[0043] Figure 2 It is a schematic structural diagram of the tube-sheet type automatic backwashing filter in the present utility model;

[0044] The reference numerals in the figure are named as follows: 1, gasifier; 2, shell-and-tube type automatic backwashing filter; 3, slag water recovery device; 4, hydraulic turbine equipment; 5, first heat exchanger; 6, second heat exchanger; 21, double-tube filtering unit; 22, backwashing main pipe; 23, filtrate main pipe; 24, slag water main pipe; 25, slag discharge main pipe; 26, pipeline pump. Detailed implementation mode

[0045] The following is a detailed description of the utility model in combination with embodiments:

[0046] The utility model provides a treatment and energy recovery system for high-solid-content black water. The system filters through a shell-and-tube type automatic backwashing filter, and then recovers the pressure energy and waste heat of the filtrate through hydraulic turbine equipment and heat exchangers. Finally, it enters the slag water recovery device for post-treatment, greatly improving the energy recovery rate of the system and saving a large amount of energy consumption.

[0047] Embodiment 1

[0048] This embodiment provides a treatment and energy recovery system for high-solid-content black water. The system sequentially includes a gasification system, a filtration system, and an energy recovery system according to the flow direction of the black water;

[0049] The gasification system includes a gasifier 1;

[0050] The filtration system includes a shell-and-tube type automatic backwashing filter 2 and a slag water recovery device 3;

[0051] The energy recovery system includes hydraulic turbine equipment 4 and heat exchangers;

[0052] The slag water recovery device 3 is simultaneously connected to the shell-and-tube type automatic backwashing filter 2 and the heat exchanger;

[0053] The gasifier 1 provides the black water to the shell-and-tube type automatic backwashing filter 2, and the black water includes liquid and solid substances.

[0054] In this embodiment, the shell-and-tube type automatic backwashing filter 2 includes a double-tube filtering unit 21, and a backwashing main pipe 22, a filtrate main pipe 23, a slag water main pipe 24, and a slag discharge main pipe 25 arranged in sequence from top to bottom. The double-tube filtering unit 21 includes filtering pipelines on the left and right sides, a liquid outlet and a backwashing port at the top, and a liquid inlet and a slag outlet at the bottom; the backwashing main pipe 22 is provided with a backwashing water inlet, the filtrate main pipe 23 is provided with a filtrate outlet, the slag water main pipe 24 is provided with a slag water inlet, and the slag discharge main pipe 25 is provided with a filter residue outlet;

[0055] The backwash water inlet on the backwash main pipe 22 of the tubular automatic backwash filter 2 is connected to the filtrate outlet on the filtrate main pipe 23. The filtrate outlet on the filtrate main pipe 23 is also connected to the energy recovery system. The filter residue outlet on the slag discharge main pipe 25 is connected to the slag-water recovery device 3. A valve and a pipeline pump 26 are installed at the connection between the backwash water inlet on the backwash main pipe 22 and the filtrate outlet on the filtrate main pipe 23.

[0056] Flushing ports are also provided on both the backwash main pipe 22 and the slag discharge main pipe 25 of the tubular automatic backwash filter 2. A valve is installed on the pipeline connecting the flushing port of the backwash main pipe 22 and the flushing port of the slag discharge main pipe 25. The flushing port of the backwash main pipe 22 is also connected to the slag outlet of the double-tube filter unit 21.

[0057] The slag-water inlet on the slag-water main pipe 24 of the tubular automatic backwash filter 2 is connected to the slag outlet of the gasifier 1.

[0058] Cylindrical sintered metal filter elements are installed in the filter pipes on both the left and right sides of the double-tube filter unit 21. The bottom of the sintered metal filter element is of an open structure, and the top is a sealed screen structure. The outer wall of the sintered metal filter element is welded to the inner wall of the filter pipe without a gap. The pore size of the sintered metal filter element is 15 μm.

[0059] The liquid outlet at the top of the double-tube filter unit 21 is connected to the filtrate main pipe 23, and the backwash port at the top of the double-tube filter unit 21 is connected to the backwash main pipe 22.

[0060] The liquid inlet at the bottom of the double-tube filter unit 21 is connected to the slag-water main pipe 24, and the slag outlet at the bottom of the double-tube filter unit 21 is connected to the slag discharge main pipe 25.

[0061] Valves are installed at the liquid outlet, backwash port, liquid inlet, and slag outlet at the top of the double-tube filter unit 21.

[0062] A differential pressure gauge (PD) is connected by a signal line at the liquid inlet and outlet of the double-tube filter unit 21. The differential pressure gauge (PD) is connected by a signal line to a control device. The control device is connected by a signal line to the valves at the backwash port, liquid outlet, liquid inlet, and slag outlet of the double-tube filter unit 21 to control the opening and closing of the valves at the backwash port, liquid outlet, liquid inlet, and slag outlet of the double-tube filter unit 21.

[0063] When the slag discharge main pipe 25 and the slag outlet of the double-tube filtration unit 21 are blocked, the valve and the pipeline pump 26 at the connection between the backwash water inlet on the backwash main pipe 22 and the filtrate outlet on the filtrate main pipe 23 are opened, and the valve connecting the flush port of the backwash main pipe 22 to the flush port of the slag discharge main pipe 25 is opened. The blocked parts of the slag discharge main pipe 25 and the slag outlet of the double-tube filtration unit 21 are flushed with the filtrate in the backwash main pipe 22;

[0064] When the blockage at the slag outlet of the slag discharge main pipe 25 and the double-tube filtration unit 21 is flushed away, the valve and the pipeline pump 26 at the connection between the backwash water inlet on the backwash main pipe 22 and the filtrate outlet on the filtrate main pipe 23, and the valve on the pipeline connecting the flush port of the backwash main pipe 22 to the flush port of the slag discharge main pipe 25 are closed;

[0065] A detachable T-shaped filter screen with a pore size of 15 μm is installed at the flush port on the backwash main pipe 22 of the tubular automatic backwash filter 2;

[0066] Wear-resistant layer structures are provided on one side of the inner walls of the filter pipes on the left and right sides of the double-tube filtration unit 21, as well as the backwash main pipe 22, the filtrate main pipe 23, the slag-water main pipe 24, and the slag discharge main pipe 25;

[0067] The number of the double-tube filtration units 21 is greater than or equal to 2. When the starting pressure difference (P 启动 ) of the differential pressure gauge (PD) connected between the liquid inlet and the liquid outlet of one of the double-tube filtration units 21 is greater than the upper limit of the pressure difference (P max ), the control device controls the valves at the liquid inlet and the liquid outlet of this double-tube filtration unit 21 to close, controls the valves at the backwash port and the slag outlet of this double-tube filtration unit 21 to open, and opens the valve and the pipeline pump 26 at the connection between the backwash water inlet on the backwash main pipe 22 and the filtrate outlet on the filtrate main pipe 23;

[0068] When the starting pressure difference (P 启动 ) of the differential pressure gauge (PD) connected between the liquid inlet and the liquid outlet of the double-tube filtration unit 21 is less than the lower limit of the pressure difference (P min ), the control device controls the valves at the backwash port and the slag outlet of this double-tube filtration unit 21 to close, closes the valve and the pipeline pump 26 at the connection between the backwash water inlet on the backwash main pipe 22 and the filtrate outlet on the filtrate main pipe 23, and then opens the valves at the liquid inlet and the liquid outlet of this double-tube filtration unit 21;

[0069] The starting pressure difference (P 启动 ) of the differential pressure gauge (PD) between the liquid inlet and the liquid outlet of the double-tube filtration unit 21 = the pressure at the liquid inlet of the double-tube filtration unit 21 (P 进液口- The pressure at the liquid outlet of the double - tube filtration unit 21 (P 出液口 ); The upper limit of the pressure difference (P max ) is 200 kPa, and the lower limit of the pressure difference (P min ) is 100 kPa;

[0070] The liquid inlet of the hydraulic turbine device 4 is connected to the filtrate outlet on the main filtrate pipe 23 of the tubular automatic back - washing filter 2, and the liquid outlet of the hydraulic turbine device 4 is connected to the heat exchanger;

[0071] The heat exchanger includes a hot fluid inlet, a hot fluid outlet, a cold fluid inlet, and a cold fluid outlet; The hot fluid inlet of the heat exchanger is connected to the liquid outlet of the hydraulic turbine device 4, and the hot fluid outlet of the heat exchanger is connected to the slag - water recovery device 3;

[0072] The hot fluid inlet of the heat exchanger is placed in the upper left of the heat exchanger, and the hot fluid outlet is placed in the lower left of the heat exchanger; The cold fluid inlet of the heat exchanger is placed in the upper right of the heat exchanger, and the cold fluid outlet is placed in the lower right of the heat exchanger;

[0073] The number of the heat exchangers is 2, which are divided into the first heat exchanger 5 and the second heat exchanger 6. Among them, the hot fluid inlet of the first heat exchanger 5 is connected to the liquid outlet of the hydraulic turbine device 4; The hot fluid inlet in the second heat exchanger 6 is connected to the liquid outlet of the hydraulic turbine device 4 and is also connected to the hot fluid outlet of the first heat exchanger 5; The hot fluid outlet of the second heat exchanger 6 is connected to the slag - water recovery device 3;

[0074] The temperature of the filtrate at the liquid outlet of the hydraulic turbine device 4 is 134.8 °C, and the filtrate only passes through the second heat exchanger 6;

[0075] The hot fluid in both the hot fluid inlet and the hot fluid outlet of the second heat exchanger 6 is the filtrate flowing out from the liquid outlet of the hydraulic turbine device 4. The cold fluid inlet of the second heat exchanger 6 is low - temperature desalted water, and the cold fluid outlet of the second heat exchanger 6 is high - temperature desalted water;

[0076] The temperature of the low - temperature desalted water at the cold fluid inlet of the second heat exchanger 6 is 25 °C, and the flow rate is 190 t / h. The temperature of the high - temperature desalted water at the cold fluid outlet of the second heat exchanger 6 is 99 °C.

[0077] In this embodiment, the electric energy recovered by the hydraulic turbine device 4 in the high - solid - content black - water treatment and energy recovery system is 491.2 kWh. The reduction in the amount of circulating water used in the high - solid - content black - water treatment and energy recovery system is 867.6 t / h, and the solid - content removal rate is 90%.

[0078] Embodiment 2

[0079] This embodiment provides a treatment and energy recovery system for high-solid-content black water. The system sequentially includes a gasification system, a filtration system, and an energy recovery system according to the flow direction of the black water;

[0080] The gasification system includes a gasification furnace 1;

[0081] The filtration system includes a shell-and-tube automatic backwashing filter 2 and a slag water recovery device 3;

[0082] The energy recovery system includes a hydraulic turbine device 4 and a heat exchanger;

[0083] The slag water recovery device 3 is simultaneously connected to the shell-and-tube automatic backwashing filter 2 and the heat exchanger;

[0084] The gasification furnace 1 supplies the black water to the shell-and-tube automatic backwashing filter 2, and the black water includes liquid and solid substances.

[0085] In this embodiment, the shell-and-tube automatic backwashing filter 2 includes a double-tube filtration unit 21, and a backwashing main pipe 22, a filtrate main pipe 23, a slag water main pipe 24, and a slag discharge main pipe 25 that are sequentially arranged from top to bottom. The double-tube filtration unit 21 includes filtration pipes on the left and right sides, a liquid outlet and a backwashing port at the top, and a liquid inlet and a slag outlet at the bottom; the backwashing main pipe 22 is provided with a backwashing water inlet, the filtrate main pipe 23 is provided with a filtrate outlet, the slag water main pipe 24 is provided with a slag water inlet, and the slag discharge main pipe 25 is provided with a filter residue outlet;

[0086] The backwashing water inlet on the backwashing main pipe 22 of the shell-and-tube automatic backwashing filter 2 is connected to the filtrate outlet on the filtrate main pipe 23. The filtrate outlet on the filtrate main pipe 23 is also connected to the energy recovery system. The filter residue outlet on the slag discharge main pipe 25 is connected to the slag water recovery device 3; a valve and a pipeline pump 26 are installed at the connection between the backwashing water inlet on the backwashing main pipe 22 and the filtrate outlet on the filtrate main pipe 23;

[0087] Washing ports are also provided on both the backwashing main pipe 22 and the slag discharge main pipe 25 of the shell-and-tube automatic backwashing filter 2. A valve is installed on the pipeline connecting the washing port of the backwashing main pipe 22 and the washing port of the slag discharge main pipe 25. The washing port of the backwashing main pipe 22 is also connected to the slag outlet of the double-tube filtration unit 21;

[0088] The slag water inlet on the slag water main pipe 24 of the shell-and-tube automatic backwashing filter 2 is connected to the slag outlet of the gasification furnace 1;

[0089] In the filter pipes on both the left and right sides of the double - tube filtering unit 21, cylindrical sintered metal filter elements are installed. The bottom of the sintered metal filter element is of an open structure, and the top is a sealed screen structure. The outer wall of the sintered metal filter element is welded to the inner wall of the filter pipe without a gap, and the aperture of the sintered metal filter element is 15μm;

[0090] The liquid outlet at the top of the double - tube filtering unit 21 is connected to the filtrate main pipe 23, and the back - flushing port at the top of the double - tube filtering unit 21 is connected to the back - flushing main pipe 22;

[0091] The liquid inlet at the bottom of the double - tube filtering unit 21 is connected to the slag - water main pipe 24, and the slag outlet at the bottom of the double - tube filtering unit 21 is connected to the slag - discharging main pipe 25;

[0092] Valves are installed at the liquid outlet, back - flushing port, liquid inlet, and slag outlet at the top and bottom of the double - tube filtering unit 21;

[0093] A differential pressure gauge (PD) is connected by a signal line at the liquid inlet and outlet of the double - tube filtering unit 21. The differential pressure gauge (PD) is connected to a control device by a signal line, and the control device is connected to the valves at the back - flushing port, liquid outlet, liquid inlet, and slag outlet of the double - tube filtering unit 21 through signal lines to control the opening and closing of the valves at the back - flushing port, liquid outlet, liquid inlet, and slag outlet of the double - tube filtering unit 21;

[0094] When the slag - discharging main pipe 25 and the slag outlet of the double - tube filtering unit 21 are blocked, the valve and the pipeline pump 26 at the connection between the back - flushing water inlet on the back - flushing main pipe 22 and the filtrate outlet on the filtrate main pipe 23 will be opened, and the valve connecting the flushing port of the back - flushing main pipe 22 and the flushing port of the slag - discharging main pipe 25 will be opened. The blocked part of the slag - discharging main pipe 25 and the slag outlet of the double - tube filtering unit 21 will be flushed with the filtrate in the back - flushing main pipe 22;

[0095] When the blockage at the slag - discharging main pipe 25 and the slag outlet of the double - tube filtering unit 21 is flushed open, the valve and the pipeline pump 26 at the connection between the back - flushing water inlet on the back - flushing main pipe 22 and the filtrate outlet on the filtrate main pipe 23, and the valve on the pipeline connecting the flushing port of the back - flushing main pipe 22 and the flushing port of the slag - discharging main pipe 25 will be closed;

[0096] A detachable T - shaped filter screen with an aperture of 15μm is installed at the flushing port on the back - flushing main pipe 22 of the tubular automatic back - flushing filter 2;

[0097] On one side of the inner walls of the filter pipes on both the left and right sides of the double - tube filtering unit 21, as well as the back - flushing main pipe 22, filtrate main pipe 23, slag - water main pipe 24, and slag - discharging main pipe 25, wear - resistant layer structures are provided;

[0098] The number of the double-tube filtering units 21 is greater than or equal to 2. When the starting pressure difference (P 启动 ) of the pressure difference gauge (PD) connected to the liquid inlet and outlet of one of the double-tube filtering units 21 is greater than the upper limit of the pressure difference (P max ), the control device controls the valves at the liquid inlet and outlet of this double-tube filtering unit 21 to close, controls the valves at the backwash port and slag discharge port of this double-tube filtering unit 21 to open, and opens the valve and the pipeline pump 26 at the connection between the backwash water inlet on the backwash main pipe 22 and the filtrate outlet on the filtrate main pipe 23;

[0099] When the starting pressure difference (P 启动 ) of the pressure difference gauge (PD) connected to the liquid inlet and outlet of the double-tube filtering unit 21 is less than the lower limit of the pressure difference (P min ), the control device controls the valves at the backwash port and slag discharge port of this double-tube filtering unit 21 to close, closes the valve and the pipeline pump 26 at the connection between the backwash water inlet on the backwash main pipe 22 and the filtrate outlet on the filtrate main pipe 23, and then opens the valves at the liquid inlet and outlet of this double-tube filtering unit 21;

[0100] The starting pressure difference (P 启动 ) of the pressure difference gauge (PD) at the liquid inlet and outlet of the double-tube filtering unit 21 = the pressure (P 进液口 ) at the liquid inlet of the double-tube filtering unit 21 - the pressure (P 出液口 ) at the liquid outlet of the double-tube filtering unit 21; the upper limit of the pressure difference (P max ) is 200 kPa, and the lower limit of the pressure difference (P min ) is 100 kPa;

[0101] The liquid inlet of the hydraulic turbine device 4 is connected to the filtrate outlet on the filtrate main pipe 23 of the tubular automatic backwash filter 2, and the liquid outlet of the hydraulic turbine device 4 is connected to the heat exchanger;

[0102] The heat exchanger includes a hot fluid inlet, a hot fluid outlet, a cold fluid inlet, and a cold fluid outlet; the hot fluid inlet of the heat exchanger is connected to the liquid outlet of the hydraulic turbine device 4, and the hot fluid outlet of the heat exchanger is connected to the slag water recovery device 3;

[0103] The hot fluid inlet of the heat exchanger is located at the upper left of the heat exchanger, and the hot fluid outlet is located at the lower left of the heat exchanger; the cold fluid inlet of the heat exchanger is located at the upper right of the heat exchanger, and the cold fluid outlet is located at the lower right of the heat exchanger;

[0104] The number of the heat exchangers is 2, which are divided into a first heat exchanger 5 and a second heat exchanger 6. The hot fluid inlet of the first heat exchanger 5 is connected to the liquid outlet of the hydraulic turbine device 4; the hot fluid inlet of the second heat exchanger 6 is connected to the liquid outlet of the hydraulic turbine device 4 and is also connected to the hot fluid outlet of the first heat exchanger 5; the hot fluid outlet of the second heat exchanger 6 is connected to the slag water recovery device 3.

[0105] The temperature of the filtrate at the liquid outlet of the hydraulic turbine device 4 is 203.6 °C. The filtrate first passes through the first heat exchanger 5 and then through the second heat exchanger 6.

[0106] The hot fluid in the hot fluid inlets and outlets of the first heat exchanger 5 and the second heat exchanger 6 is the filtrate flowing out of the liquid outlet of the hydraulic turbine device 4. The cold fluid inlet of the first heat exchanger 5 is high-temperature boiler water, and the cold fluid outlet of the first heat exchanger 5 is saturated steam. The cold fluid inlet of the second heat exchanger 6 is low-temperature desalted water, and the cold fluid outlet of the second heat exchanger 6 is high-temperature desalted water.

[0107] The pressure of the saturated steam at the cold fluid outlet of the first heat exchanger 5 is 0.5 MPa, and the flow rate is 17.1 t / h. The recovered heat energy in the first heat exchanger 5 is equivalent to reducing the carbon dioxide emission by 3539.8 kg. The temperature of the low-temperature desalted water at the cold fluid inlet of the second heat exchanger 6 is 25 °C, and the flow rate is 280 t / h. The temperature of the high-temperature desalted water at the cold fluid outlet of the second heat exchanger 6 is 99 °C.

[0108] In this embodiment, the electric energy recovered by the hydraulic turbine device 4 in the high-solid-content black water treatment and energy recovery system is 155 kWh. The reduction in the circulating water consumption of the high-solid-content black water treatment and energy recovery system is 476.6 t / h, and the solid content removal rate is 70%.

[0109] Embodiment 3

[0110] This embodiment provides a high-solid-content black water treatment and energy recovery system. The system sequentially includes a gasification system, a filtration system, and an energy recovery system according to the flow direction of the black water.

[0111] The gasification system includes a gasifier 1.

[0112] The filtration system includes a tubular automatic backwashing filter 2 and a slag water recovery device 3.

[0113] The energy recovery system includes a hydraulic turbine device 4 and a heat exchanger.

[0114] The slag water recovery device 3 is simultaneously connected to the tubular automatic backwashing filter 2 and the heat exchanger.

[0115] The gasifier 1 supplies the black water to the tubular automatic backwashing filter 2, and the black water includes liquid and solid substances.

[0116] In this embodiment, the tubular automatic backwashing filter 2 includes a double-tube filtering unit 21, and a backwashing main pipe 22, a filtrate main pipe 23, a slag water main pipe 24, and a slag discharging main pipe 25 which are arranged in sequence from top to bottom. The double-tube filtering unit 21 includes filtering pipes on the left and right sides, a liquid outlet and a backwashing port at the top, and a liquid inlet and a slag outlet at the bottom; the backwashing main pipe 22 is provided with a backwashing water inlet, the filtrate main pipe 23 is provided with a filtrate outlet, the slag water main pipe 24 is provided with a slag water inlet, and the slag discharging main pipe 25 is provided with a filter residue outlet;

[0117] The backwashing water inlet on the backwashing main pipe 22 of the tubular automatic backwashing filter 2 is connected to the filtrate outlet on the filtrate main pipe 23. The filtrate outlet on the filtrate main pipe 23 is also connected to the energy recovery system. The filter residue outlet on the slag discharging main pipe 25 is connected to the slag water recovery device 3; a valve and a pipeline pump 26 are installed at the connection between the backwashing water inlet on the backwashing main pipe 22 and the filtrate outlet on the filtrate main pipe 23;

[0118] Washing ports are also provided on both the backwashing main pipe 22 and the slag discharging main pipe 25 of the tubular automatic backwashing filter 2. A valve is installed on the pipeline connecting the washing port of the backwashing main pipe 22 and the washing port of the slag discharging main pipe 25. The washing port of the backwashing main pipe 22 is also connected to the slag outlet of the double-tube filtering unit 21;

[0119] The slag water inlet on the slag water main pipe 24 of the tubular automatic backwashing filter 2 is connected to the slag outlet of the gasifier 1;

[0120] Cylindrical sintered metal filters are installed in the filtering pipes on both the left and right sides of the double-tube filtering unit 21. The bottom of the sintered metal filter is of an open structure, and the top is a sealed screen structure. The outer wall of the sintered metal filter is welded to the inner wall of the filtering pipe without gaps, and the aperture of the sintered metal filter is 15 μm;

[0121] The liquid outlet at the top of the double-tube filtering unit 21 is connected to the filtrate main pipe 23, and the backwashing port at the top of the double-tube filtering unit 21 is connected to the backwashing main pipe 22;

[0122] The liquid inlet at the bottom of the double-tube filtering unit 21 is connected to the slag water main pipe 24, and the slag outlet at the bottom of the double-tube filtering unit 21 is connected to the slag discharging main pipe 25;

[0123] Valves are installed at the liquid outlet and the backwashing port at the top of the double-tube filtering unit 21, and at the liquid inlet and the slag outlet at the bottom of the double-tube filtering unit 21;

[0124] A differential pressure gauge (PD) is connected by signal lines at the liquid inlet and outlet of the double-tube filtration unit 21. The differential pressure gauge (PD) is connected to a control device by a signal line, and the control device is connected to the valves at the backwash port, liquid outlet, liquid inlet, and slag discharge port of the double-tube filtration unit 21 by signal lines to control the opening and closing of the valves at the backwash port, liquid outlet, liquid inlet, and slag discharge port of the double-tube filtration unit 21;

[0125] When the slag discharge main pipe 25 and the slag discharge port of the double-tube filtration unit 21 are blocked, the valve and the pipeline pump 26 at the connection between the backwash water inlet on the backwash main pipe 22 and the filtrate outlet on the filtrate main pipe 23 will be opened, and the valve connecting the flushing port of the backwash main pipe 22 and the flushing port of the slag discharge main pipe 25 will be opened. The blocked part of the slag discharge main pipe 25 and the slag discharge port of the double-tube filtration unit 21 will be flushed with the filtrate in the backwash main pipe 22;

[0126] When the blockage at the slag discharge port of the slag discharge main pipe 25 and the double-tube filtration unit 21 is flushed open, the valve and the pipeline pump 26 at the connection between the backwash water inlet on the backwash main pipe 22 and the filtrate outlet on the filtrate main pipe 23, and the valve on the pipeline connecting the flushing port of the backwash main pipe 22 and the flushing port of the slag discharge main pipe 25 will be closed;

[0127] A detachable T-shaped filter screen with a pore size of 15 μm is installed at the flushing port on the backwash main pipe 22 of the tubular automatic backwash filter 2;

[0128] Wear-resistant layer structures are provided on one side of the inner walls of the filter pipes on the left and right sides of the double-tube filtration unit 21, as well as the backwash main pipe 22, filtrate main pipe 23, slag water main pipe 24, and slag discharge main pipe 25;

[0129] The number of the double-tube filtration units 21 is greater than or equal to 2. When the start-up differential pressure (P 启动 ) of the differential pressure gauge (PD) connected at the liquid inlet and outlet of one of the double-tube filtration units 21 is greater than the differential pressure upper limit (P max ), the control device controls the valve at the liquid inlet and outlet of this double-tube filtration unit 21 to close, controls the valves at the backwash port and slag discharge port of this double-tube filtration unit 21 to open, and opens the valve and the pipeline pump 26 at the connection between the backwash water inlet on the backwash main pipe 22 and the filtrate outlet on the filtrate main pipe 23;

[0130] When the start-up differential pressure (P 启动 ) of the differential pressure gauge (PD) connected at the liquid inlet and outlet of the double-tube filtration unit 21 is less than the differential pressure lower limit (P minWhen (), the control device closes the valves at the backwash port and slag discharge port of the double-tube filtration unit 21, closes the valve and the pipeline pump 26 at the connection between the backwash water inlet on the backwash main pipe 22 and the filtrate outlet on the filtrate main pipe 23, and then opens the valves at the liquid inlet and liquid outlet of the double-tube filtration unit 21;

[0131] The start-up differential pressure (P 启动 ) of the differential pressure gauge (PD) at the liquid inlet and liquid outlet of the double-tube filtration unit 21 = the pressure (P 进液口 ) at the liquid inlet of the double-tube filtration unit 21 - the pressure (P 出液口 ) at the liquid outlet of the double-tube filtration unit 21; The upper differential pressure limit (P max ) is 200 kPa, and the lower differential pressure limit (P min ) is 100 kPa;

[0132] The liquid inlet of the hydraulic turbine device 4 is connected to the filtrate outlet on the filtrate main pipe 23 of the tubular automatic backwash filter 2, and the liquid outlet of the hydraulic turbine device 4 is connected to the heat exchanger;

[0133] The heat exchanger includes a hot fluid inlet, a hot fluid outlet, a cold fluid inlet and a cold fluid outlet; The hot fluid inlet of the heat exchanger is connected to the liquid outlet of the hydraulic turbine device 4, and the hot fluid outlet of the heat exchanger is connected to the slag water recovery device 3;

[0134] The hot fluid inlet of the heat exchanger is placed in the upper left of the heat exchanger, and the hot fluid outlet is placed in the lower left of the heat exchanger; The cold fluid inlet of the heat exchanger is placed in the upper right of the heat exchanger, and the cold fluid outlet is placed in the lower right of the heat exchanger;

[0135] The number of the heat exchangers is 2, which are divided into a first heat exchanger 5 and a second heat exchanger 6. Among them, the hot fluid inlet of the first heat exchanger 5 is connected to the liquid outlet of the hydraulic turbine device 4; The hot fluid inlet in the second heat exchanger 6 is connected to the liquid outlet of the hydraulic turbine device 4 and is also connected to the hot fluid outlet of the first heat exchanger 5; The hot fluid outlet of the second heat exchanger 6 is connected to the slag water recovery device 3;

[0136] The temperature of the filtrate at the liquid outlet of the hydraulic turbine device 4 is 147.6 °C, and the filtrate only passes through the second heat exchanger 6;

[0137] The hot fluid in the hot fluid inlet and hot fluid outlet of the second heat exchanger 6 is the filtrate flowing out of the liquid outlet of the hydraulic turbine device 4. The cold fluid inlet of the second heat exchanger 6 is low-temperature desalted water, and the cold fluid outlet of the second heat exchanger 6 is high-temperature desalted water;

[0138] The temperature of the low-temperature desalted water at the cold fluid inlet of the second heat exchanger 6 is 25°C, and the flow rate is 280 t / h. The temperature of the high-temperature desalted water at the cold fluid outlet of the second heat exchanger 7 is 99°C.

[0139] In this embodiment, the electric energy recovered by the hydraulic turbine device 4 in the high-solid-content black water treatment and energy recovery system is 728 kWh. The reduction in the circulating water consumption of the high-solid-content black water treatment and energy recovery system is 1060 t / h, and the solid content removal rate is 80%.

[0140] Embodiment 4

[0141] This embodiment provides a high-solid-content black water treatment and energy recovery system. The system sequentially includes a gasification system, a filtration system, and an energy recovery system according to the flow direction of the black water;

[0142] The gasification system includes a gasifier 1;

[0143] The filtration system includes a shell-and-tube automatic backwashing filter 2 and a slag water recovery device 3;

[0144] The energy recovery system includes a hydraulic turbine device 4 and a heat exchanger;

[0145] The slag water recovery device 3 is simultaneously connected to the shell-and-tube automatic backwashing filter 2 and the heat exchanger;

[0146] The gasifier 1 supplies the black water to the shell-and-tube automatic backwashing filter 2, and the black water includes liquid and solid substances.

[0147] In this embodiment, the shell-and-tube automatic backwashing filter 2 includes a double-tube filtration unit 21, and a backwash main pipe 22, a filtrate main pipe 23, a slag water main pipe 24, and a slag discharge main pipe 25 arranged in sequence from top to bottom. The double-tube filtration unit 21 includes filtration pipes on the left and right sides, a liquid outlet and a backwash port at the top, and a liquid inlet and a slag outlet at the bottom; the backwash main pipe 22 is provided with a backwash water inlet, the filtrate main pipe 23 is provided with a filtrate outlet, the slag water main pipe 24 is provided with a slag water inlet, and the slag discharge main pipe 25 is provided with a filter residue outlet;

[0148] The backwash water inlet on the backwash main pipe 22 of the shell-and-tube automatic backwashing filter 2 is connected to the filtrate outlet on the filtrate main pipe 23. The filtrate outlet on the filtrate main pipe 23 is also connected to the energy recovery system. The filter residue outlet on the slag discharge main pipe 25 is connected to the slag water recovery device 3; a valve and a pipeline pump 26 are installed at the connection between the backwash water inlet on the backwash main pipe 22 and the filtrate outlet on the filtrate main pipe 23;

[0149] The backflush main pipe 22 and the slag discharge main pipe 25 of the tubular automatic backflush filter 2 are both provided with flushing ports. A valve is installed on the pipeline connecting the flushing port of the backflush main pipe 22 and the flushing port of the slag discharge main pipe 25. The flushing port of the backflush main pipe 22 is also connected to the slag discharge port of the double-pipe filtering unit 21.

[0150] The slag water inlet on the slag water main pipe 24 of the tubular automatic backflush filter 2 is connected to the slag discharge port of the gasifier 1.

[0151] Cylindrical sintered metal filter elements are installed in the filter pipes on both the left and right sides of the double-pipe filtering unit 21. The bottom of the sintered metal filter element is of an open structure, and the top is a sealed screen structure. The outer wall of the sintered metal filter element is welded to the inner wall of the filter pipe without gaps. The aperture of the sintered metal filter element is 15μm.

[0152] The liquid outlet at the top of the double-pipe filtering unit 21 is connected to the filtrate main pipe 23, and the backflush port at the top of the double-pipe filtering unit 21 is connected to the backflush main pipe 22.

[0153] The liquid inlet at the bottom of the double-pipe filtering unit 21 is connected to the slag water main pipe 24, and the slag discharge port at the bottom of the double-pipe filtering unit 21 is connected to the slag discharge main pipe 25.

[0154] Valves are installed at the liquid outlet, backflush port, liquid inlet, and slag discharge port at the top of the double-pipe filtering unit 21.

[0155] A differential pressure gauge (PD) is connected by a signal line at the liquid inlet and outlet of the double-pipe filtering unit 21. The differential pressure gauge (PD) is connected by a signal line to a control device, and the control device is connected by a signal line to the valves at the backflush port, liquid outlet, liquid inlet, and slag discharge port of the double-pipe filtering unit 21 to control the opening and closing of the valves at the backflush port, liquid outlet, liquid inlet, and slag discharge port of the double-pipe filtering unit 21.

[0156] When the slag discharge main pipe 25 and the slag discharge port of the double-pipe filtering unit 21 are blocked, the valve and the pipeline pump 26 at the connection between the backflush water inlet on the backflush main pipe 22 and the filtrate outlet on the filtrate main pipe 23 will be opened, and the valve connecting the flushing port of the backflush main pipe 22 and the flushing port of the slag discharge main pipe 25 will be opened. The blocked parts of the slag discharge main pipe 25 and the slag discharge port of the double-pipe filtering unit 21 will be flushed with the filtrate in the backflush main pipe 22.

[0157] When the blockage at the slag discharge main pipe 25 and the slag outlet of the double-tube filtration unit 21 is flushed open, close the valve and the pipeline pump 26 at the connection between the backflush water inlet on the backflush main pipe 22 and the filtrate outlet on the filtrate main pipe 23, and the valve on the connecting pipeline between the flushing port of the backflush main pipe 22 and the flushing port of the slag discharge main pipe 25;

[0158] A detachable T-shaped filter screen is installed at the flushing port on the backflush main pipe 22 of the tubular automatic backflush filter 2, and the aperture of the T-shaped filter screen is 15μm;

[0159] Wear-resistant layer structures are provided on one side of the inner walls of the filter pipes on the left and right sides of the double-tube filtration unit 21, as well as the backflush main pipe 22, the filtrate main pipe 23, the slag-water main pipe 24, and the slag discharge main pipe 25;

[0160] The number of the double-tube filtration units 21 is greater than or equal to 2. When the starting pressure difference (P 启动 ) of the pressure difference gauge (PD) connected at the liquid inlet and the liquid outlet of one of the double-tube filtration units 21 is greater than the upper limit of the pressure difference (P max ), the control device controls the valves at the liquid inlet and the liquid outlet of this double-tube filtration unit 21 to close, controls the valves at the backflush port and the slag outlet of this double-tube filtration unit 21 to open, and opens the valve and the pipeline pump 26 at the connection between the backflush water inlet on the backflush main pipe 22 and the filtrate outlet on the filtrate main pipe 23;

[0161] When the starting pressure difference (P 启动 ) of the pressure difference gauge (PD) connected at the liquid inlet and the liquid outlet of the double-tube filtration unit 21 is less than the lower limit of the pressure difference (P min ), the control device controls the valves at the backflush port and the slag outlet of this double-tube filtration unit 21 to close, closes the valve and the pipeline pump 26 at the connection between the backflush water inlet on the backflush main pipe 22 and the filtrate outlet on the filtrate main pipe 23, and then opens the valves at the liquid inlet and the liquid outlet of this double-tube filtration unit 21;

[0162] The starting pressure difference (P 启动 ) of the pressure difference gauge (PD) at the liquid inlet and the liquid outlet of the double-tube filtration unit 21 = the pressure (P 进液口 ) at the liquid inlet of the double-tube filtration unit 21 - the pressure (P 出液口 ) at the liquid outlet of the double-tube filtration unit 21; the upper limit of the pressure difference (P max ) is 200 kPa, and the lower limit of the pressure difference (P min ) is 100 kPa;

[0163] The liquid inlet of the hydraulic turbine device 4 is connected to the filtrate outlet on the main filtrate pipe 23 of the tubular automatic backwashing filter 2, and the liquid outlet of the hydraulic turbine device 4 is connected to the heat exchanger;

[0164] The heat exchanger includes a hot fluid inlet, a hot fluid outlet, a cold fluid inlet, and a cold fluid outlet; the hot fluid inlet of the heat exchanger is connected to the liquid outlet of the hydraulic turbine device 4, and the hot fluid outlet of the heat exchanger is connected to the slag water recovery device 3;

[0165] The hot fluid inlet of the heat exchanger is placed in the upper left of the heat exchanger, and the hot fluid outlet is placed in the lower left of the heat exchanger; the cold fluid inlet of the heat exchanger is placed in the upper right of the heat exchanger, and the cold fluid outlet is placed in the lower right of the heat exchanger;

[0166] The number of the heat exchangers is 2, which are divided into a first heat exchanger 5 and a second heat exchanger 6. The hot fluid inlet of the first heat exchanger 5 is connected to the liquid outlet of the hydraulic turbine device 4; the hot fluid inlet in the second heat exchanger 6 is connected to the liquid outlet of the hydraulic turbine device 4 and is also connected to the hot fluid outlet of the first heat exchanger 5; the hot fluid outlet of the second heat exchanger 6 is connected to the slag water recovery device 3;

[0167] The temperature of the filtrate at the liquid outlet of the hydraulic turbine device 4 is 225.8 °C. The filtrate first passes through the first heat exchanger 5 and then through the second heat exchanger 6;

[0168] The hot fluid in the hot fluid inlets and hot fluid outlets of the first heat exchanger 5 and the second heat exchanger 6 is the filtrate flowing out of the liquid outlet of the hydraulic turbine device 4. The cold fluid inlet of the first heat exchanger 5 is high-temperature boiler water, and the cold fluid outlet of the first heat exchanger 5 is saturated steam. The cold fluid inlet of the second heat exchanger 6 is low-temperature desalted water, and the cold fluid outlet of the second heat exchanger 6 is high-temperature desalted water;

[0169] The pressure of the saturated steam at the cold fluid outlet of the first heat exchanger 5 is 0.5 MPa, and the flow rate is 23.3 t / h. The recovered heat energy in the first heat exchanger 5 is equivalent to reducing carbon dioxide emissions by 4,823.2 kg. The temperature of the low-temperature desalted water at the cold fluid inlet of the second heat exchanger 6 is 25 °C, and the flow rate is 240 t / h. The temperature of the high-temperature desalted water at the cold fluid outlet of the second heat exchanger 7 is 99 °C.

[0170] In this embodiment, the electric energy recovered by the hydraulic turbine device 4 in the high-solid-content black water treatment and energy recovery system is 344 kWh. The reduction in the circulating water consumption of the high-solid-content black water treatment and energy recovery system is 800 t / h, and the solid content removal rate is 76%.

[0171] Table 1 shows the performance of the treatment and energy recovery system for high-solid-content black water described in Examples 1-4 of this embodiment

[0172]

[0173] From the above, it can be seen that the treatment and energy recovery system for high-solid-content black water described in this application has low energy consumption, low equipment wear rate, a very wide range of applications, low cost, and extremely high market prospects.

[0174] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any other form. Any modification or equivalent change made based on the technical essence of the present invention still falls within the scope of protection required by the present invention.

Claims

1. A high solid content black water treatment and energy recovery system, characterized in that: The system includes a gasification system, a filtration system and an energy recovery system in sequence according to the flow direction of the black water; The gasification system comprises a gasifier (1); The filtration system comprises a tubular automatic backwash filter (2) and a slag water recovery device (3); The energy recovery system comprises a hydraulic turbine device (4) and a heat exchanger; The slag water recovery device (3) is connected to the tubular automatic backwash filter (2) and the heat exchanger at the same time; The gasifier (1) provides the black water to the tube-in-tube automatic backwash filter (2), wherein the black water includes liquid and solid substances.

2. The high solid content black water treatment and energy recovery system according to claim 1, characterized in that: The tubular automatic backwash filter (2) comprises a double-tube filter unit (21), and a backwash main pipe (22), a filtrate main pipe (23), a slag water main pipe (24), and a slag discharge main pipe (25) arranged in sequence from top to bottom, wherein the double-tube filter unit (21) comprises filter pipes on left and right sides, a liquid outlet and a backwash port at the top, and a liquid inlet and a slag discharge port at the bottom; the backwash main pipe (22) is provided with a backwash water inlet, the filtrate main pipe (23) is provided with a filtrate outlet, the slag water main pipe (24) is provided with a slag water inlet, and the slag discharge main pipe (25) is provided with a filtrate outlet.

3. The high solid content black water treatment and energy recovery system according to claim 2, characterized in that: The recoil main pipe (22) and the slag discharge main pipe (25) of the tubular automatic backwash filter (2) are both provided with flushing ports, a valve is installed on the pipe connecting the flushing port of the recoil main pipe (22) and the flushing port of the slag discharge main pipe (25), and the flushing port of the recoil main pipe (22) is also connected to the slag discharge port of the double-tube filter unit (21).

4. The high solid content black water treatment and energy recovery system according to claim 2, characterized in that: The liquid outlet at the top of the double-tube filter unit (21) is connected to the filtrate main pipe (23), and the backwash port at the top of the double-tube filter unit (21) is connected to the backwash main pipe (22); The liquid inlet at the bottom of the double-tube filter unit (21) is connected to the slag water main pipe (24), and the slag outlet at the bottom of the double-tube filter unit (21) is connected to the slag discharge main pipe (25); The liquid outlet and the backwash outlet at the top of the double-tube filter unit (21) and the liquid inlet and the slag outlet at the bottom of the double-tube filter unit (21) are all equipped with valves.

5. The high solid content black water treatment and energy recovery system according to claim 2, characterized in that: When the slag discharge main pipe (25) and the slag discharge port of the double-tube filter unit (21) are blocked, the valve and the pipeline pump (26) at the connection between the backwash water inlet on the backwash main pipe (22) and the filtrate outlet on the filtrate main pipe (23) are opened, and the valve connecting the flushing port of the backwash main pipe (22) and the flushing port of the slag discharge main pipe (25) is opened, so that the blocked slag discharge port of the slag discharge main pipe (25) and the double-tube filter unit (21) are flushed by the filtrate in the backwash main pipe (22); When the blockages at the slag discharge main pipe (25) and the slag discharge port of the double-tube filtration unit (21) are cleared, the valve and pipeline pump (26) at the connection between the backwash water inlet on the backwash main pipe (22) and the filtrate outlet on the filtrate main pipe (23) are closed, as well as the valve on the pipeline connecting the flushing port of the backwash main pipe (22) and the flushing port of the slag discharge main pipe (25).

6. The high solid content black water treatment and energy recovery system according to claim 2, characterized in that: The flushing port on the backwashing main pipe (22) of the tubular automatic backwashing filter (2) is equipped with a detachable T-shaped filter screen.

7. The high solid content black water treatment and energy recovery system according to claim 1, characterized in that: The liquid inlet of the hydraulic turbine device (4) is connected to the filtrate outlet on the filtrate main pipe (23) of the shell-and-tube automatic backwashing filter (2), and the liquid outlet of the hydraulic turbine device (4) is connected to the heat exchanger.

8. The high solid content black water treatment and energy recovery system according to claim 1, characterized in that: The heat exchanger comprises a hot fluid inlet, a hot fluid outlet, a cold fluid inlet and a cold fluid outlet; the hot fluid inlet of the heat exchanger is connected to the liquid outlet of the hydraulic turbine device (4), and the hot fluid outlet of the heat exchanger is connected to the slag water recovery device (3).

9. The high solid content black water treatment and energy recovery system according to claim 1, characterized in that: The hot fluid inlet of the heat exchanger is placed at the upper left of the heat exchanger, and the hot fluid outlet is placed at the lower left of the heat exchanger; the cold fluid inlet of the heat exchanger is placed at the upper right of the heat exchanger, and the cold fluid outlet is placed at the lower right of the heat exchanger.

10. The high solid content black water treatment and energy recovery system according to claim 1, characterized in that: The number of the heat exchangers is 2, which are divided into a first heat exchanger (5) and a second heat exchanger (6), wherein the hot fluid inlet of the first heat exchanger (5) is connected to the liquid outlet of the hydraulic turbine device (4); the hot fluid inlet of the second heat exchanger (6) is connected to the liquid outlet of the hydraulic turbine device (4) and is also connected to the hot fluid outlet of the first heat exchanger (5); and the hot fluid outlet of the second heat exchanger (6) is connected to the slag water recovery device (3).

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