阅读说明：本技术 水煤浆气化系统及水煤浆添加剂回收方法 (Coal water slurry gasification system and coal water slurry additive recovery method ) 是由 王向龙 侯祥生 马丽荣 高明 刘刚 彭知顺 付伟贤 李克忠 于 2020-05-29 设计创作，主要内容包括：本发明涉及煤气化技术领域,提供了一种水煤浆气化系统及水煤浆添加剂回收方法。包括制浆及输送单元、添加剂分离单元、除水单元、气化炉及收集罐,制浆及输送单元包括顺次连接的磨煤机、煤浆罐及煤浆给料泵,煤浆给料泵与添加剂分离单元连接,添加剂分离单元与除水单元连接,除水单元设置有出水口及出煤口,出水口与收集罐连接,出煤口与气化炉连接；在制浆及输送单元与气化炉之间设置了添加剂分离单元及除水单元,采用添加剂分离单元破坏添加剂与煤颗粒的吸附连接关系,使得添加剂溶于水,随后再通过除水单元将溶有添加剂的水与煤颗粒分离,回收利用添加剂,节约水煤浆气化成本。(The invention relates to the technical field of coal gasification, and provides a coal water slurry gasification system and a coal water slurry additive recovery method. The coal slurry additive gasification furnace comprises a pulping and conveying unit, an additive separating unit, a dewatering unit, a gasification furnace and a collecting tank, wherein the pulping and conveying unit comprises a coal mill, a coal slurry tank and a coal slurry feeding pump which are sequentially connected; an additive separation unit and a water removal unit are arranged between the pulping and conveying unit and the gasification furnace, the additive separation unit is adopted to destroy the adsorption connection relationship between the additive and the coal particles, so that the additive is dissolved in water, then the water in which the additive is dissolved is separated from the coal particles through the water removal unit, the additive is recycled, and the gasification cost of the coal water slurry is saved.)

1. A coal water slurry gasification system is characterized in that: including slurrying and conveying unit, additive separating element (8), dewatering unit (9), gasifier (11) and collection tank (12), slurrying and conveying unit are including coal pulverizer (3), coal slurry jar (6) and coal slurry feed pump (7) that connect in order, coal slurry feed pump (7) with additive separating element (8) are connected, additive separating element (8) with dewatering unit (9) are connected, dewatering unit (9) are provided with delivery port and coal outlet, the delivery port with collection tank (12) are connected, the coal outlet with gasifier (11) are connected.

2. The coal water slurry gasification system of claim 1, wherein: the additive separation unit (8) comprises a body and a displacing agent delivery pump (15), wherein the body is used for displacing the additive and the displacing agent, and an outlet of the displacing agent delivery pump (15) is connected with the body.

3. The coal water slurry gasification system of claim 2, wherein: the coal slurry pump comprises a body and is characterized in that the body comprises an inner cylinder (81) and an outer cylinder (82) which are coaxially arranged, the outer cylinder (82) is provided with a steam inlet (83) and a condensate outlet (84), the inner cylinder (81) is provided with a coal slurry inlet (85), a displacing agent inlet (86) and a coal slurry outlet (87), the coal slurry inlet (85) is connected with a coal slurry feeding pump (7), and the displacing agent inlet (86) is connected with a displacing agent conveying pump (15).

4. The coal-water slurry gasification system of claim 3, wherein: and a stirring unit (88) is also arranged in the inner cylinder (81).

5. The coal water slurry gasification system of claim 1, wherein: the water removal unit (9) is any one or any combination of a flash tank, a reverse osmosis device or a hydrocyclone.

6. The coal water slurry gasification system of claim 1, wherein: the device is characterized by further comprising a pressure reducing unit (13) and a buffer tank (14), wherein the collecting tank (12) is connected with the buffer tank (14) through the pressure reducing unit (13).

7. The coal-water slurry gasification system of claim 6, wherein: the buffer tank (14) is a flash tank, and the buffer tank (14) is connected with the coal mill (3).

8. The coal-water slurry gasification system of claim 7, wherein: the coal pulverizer also comprises an additive supplementing device which is connected with the coal pulverizer (3).

9. A method for recovering a coal water slurry additive is characterized by comprising the following steps: the method comprises the following steps:

A. the coal mill (3) mixes and grinds coal, water and additives to form coal water slurry, and the coal water slurry is stored in a coal slurry tank (6);

B. pumping the coal water slurry from the coal slurry tank (6) to an additive separation unit (8) through a coal slurry feeding pump (7), and destroying the adsorption connection relationship between the additive and the coal particles by the additive separation unit (8) to dissolve the additive in water;

C. the water coal slurry with the additive separated is subjected to water separation by a water removal unit (9) to dissolve the additive in the water coal slurry;

D. the separated water dissolved with the additive is recycled through the step of recycling the additive, and the water-coal-slurry with part of water removed enters a gasification furnace (11) to carry out gasification reaction.

10. The method of claim 9 for recovering a coal water slurry additive, wherein: the step B of destroying the adsorption connection relationship between the additive and the coal particles comprises the following steps: and (3) conveying the displacing agent into the additive separation unit (8) by using a displacing agent conveying pump (15), heating the coal water slurry in the additive separation unit (8), and displacing the additive from the surfaces of the coal particles into water by using the displacing agent so as to dissolve the additive into the water.

11. The method of claim 9 for recovering a coal water slurry additive, wherein: the additive recovery step in the step D comprises the following steps: the separated water with the dissolved additives firstly enters a collecting tank (12), then enters a buffer tank (14) through a pressure reducing unit (13), and the buffer tank (14) is connected with the coal mill (3) to provide the additives for the coal mill and can also provide the additives for the coal mill (3) through an additive supplementing device.

Technical Field

The invention belongs to the technical field of coal gasification, and particularly relates to a coal water slurry gasification system and a coal water slurry additive recovery method.

Background

At present, the coal water slurry is mainly applied to the coal water slurry gasification technology, is formed by mixing coal powder with certain granularity, water and an additive according to a certain proportion, has good performances such as stability and fluidity, is safe to store, convenient to transport and measure and can be transported in a long distance.

Because the coal water slurry is required to have good stability and fluidity in the process of storage and transportation, the addition of additives is needed. However, in the coal gasification process, the additive and the coal water slurry are directly combusted after entering the gasification furnace, which causes a great deal of waste.

Therefore, how to recycle the additive and save the gasification cost of the coal water slurry becomes a major problem to be solved urgently in the development of the coal water slurry gasification technology.

Disclosure of Invention

The invention aims to provide a coal water slurry gasification system, which recycles additives and saves the coal water slurry gasification cost.

In order to achieve the purpose, the invention adopts the following technical scheme: the utility model provides a coal slurry gasification system, includes slurrying and conveying unit, additive separating element, dewatering unit, gasifier and holding vessel, slurrying and conveying unit are including the coal pulverizer, coal slurry jar and the coal slurry feed pump that connect in order, and the coal slurry feed pump is connected with additive separating element, and additive separating element and dewatering unit connection, dewatering unit are provided with delivery port and coal outlet, and the delivery port is connected with the holding vessel, and the coal outlet is connected with the gasifier.

Optionally, the additive separation unit includes a body and a displacing agent delivery pump, the body is used for displacing the additive and the displacing agent, and an outlet of the displacing agent delivery pump is connected to the body.

Optionally, the body comprises an inner cylinder and an outer cylinder which are coaxially arranged, the outer cylinder is provided with a steam inlet and a condensate outlet, the inner cylinder is provided with a coal water slurry inlet, a displacing agent inlet and a coal water slurry outlet, the coal water slurry inlet is connected with a coal slurry feeding pump, and the displacing agent inlet is connected with a displacing agent delivery pump.

Optionally, a stirring unit is further arranged in the inner cylinder.

Optionally, the water removal unit is any one or any combination of a flash tank, a reverse osmosis device or a hydrocyclone.

Optionally, the device further comprises a pressure reducing unit and a buffer tank, and the collecting tank is connected with the buffer tank through the pressure reducing unit.

Optionally, the buffer tank is a flash tank, and the buffer tank is connected with the coal mill.

Optionally, the coal mill further comprises an additive supplementing device, and the additive supplementing device is connected with the coal mill.

The invention also aims to provide a method for recovering the coal water slurry additive, which can recycle the additive and save the gasification cost of the coal water slurry.

In order to achieve the purpose, the invention adopts the following technical scheme: a method for recovering a coal water slurry additive comprises the following steps:

A. mixing and grinding coal, water and an additive by a coal mill to form coal water slurry, and storing the coal water slurry into a coal slurry tank;

B. pumping the coal water slurry from the coal slurry tank to an additive separation unit by a coal slurry feeding pump, and destroying the adsorption connection relationship between the additive and the coal particles by the additive separation unit to dissolve the additive in water;

C. the water coal slurry with the additive separated is subjected to water separation by a water removal unit, wherein the additive is dissolved in the water coal slurry;

D. the separated water with the dissolved additive is recycled through the step of recycling the additive, and the coal water slurry with part of water removed enters a gasification furnace to carry out gasification reaction.

Optionally, the step B of destroying the adsorptive connection relationship between the additive and the coal particles includes the following steps: and conveying the displacing agent into the additive separation unit by using a displacing agent conveying pump, heating the coal water slurry in the additive separation unit, and displacing the additive from the surfaces of the coal particles into water by using the displacing agent so as to dissolve the additive into the water.

Optionally, the step of recovering the additive in the step D comprises the following steps: the separated water dissolved with the additives firstly enters a collecting tank and then enters a buffer tank through a pressure reducing unit, the buffer tank is connected with the coal mill to provide the additives for the coal mill, and the additives can be provided for the coal mill through an additive supplementing device.

Compared with the prior art, the additive separation unit and the water removal unit are arranged between the pulping and conveying unit and the gasification furnace, the additive separation unit is adopted to destroy the adsorption connection relationship between the additive and the coal particles, so that the additive is dissolved in water, then the water dissolved with the additive is separated from the coal particles through the water removal unit, the coal particles enter the gasification furnace for gasification reaction, the water is separated, the water is prevented from entering the gasification furnace to be evaporated, the heat in the gasification furnace is occupied, the additional energy consumption is avoided, the temperature in the gasification furnace is maintained, the water dissolved with the additive is collected through the collection tank, the additive is recovered, the additive can be reused, and the coal water slurry gasification cost is saved.

Drawings

FIG. 1 is a schematic diagram of a coal water slurry gasification system according to an embodiment of the present invention;

fig. 2 is a schematic diagram of an additive separation unit provided in an embodiment of the present invention.

Reference numerals:

1. a coal bunker; 2. a coal weighing feeder; 3. a coal mill; 4. a coal slurry discharge chute; 5. a coal slurry discharge tank pump; 6. a coal slurry tank; 7. a coal slurry feed pump; 8. an additive separation unit; 81. an inner barrel; 82. an outer cylinder; 83. a steam inlet; 84. a condensate outlet; 85. a coal water slurry inlet; 86. a displacer inlet; 87. a coal water slurry outlet; 88. a stirring unit; 9. a water removal unit; 10. a gasification burner; 11. a gasification furnace; 12. a collection tank; 13. a pressure reducing unit; 14. a buffer tank; 15. a displacer transfer pump; 16. a flow meter.

Detailed Description

In order that the above objects, features and advantages of the present invention can be more clearly understood, the present invention will be further described in detail with reference to the accompanying drawings and examples. It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments. The specific embodiments described herein are merely illustrative of the invention and are not to be construed as limiting the invention. All other embodiments, which can be derived by a person skilled in the art from the described embodiments of the invention, are within the scope of the invention.

As shown in FIG. 1, the coal water slurry gasification system provided by the invention comprises a pulping and conveying unit, an additive separation unit 8, a water removal unit 9 and a gasification burner 10, the coal slurry preparation and conveying unit comprises a coal mill 3, a coal slurry tank 6 and a coal slurry feeding pump 7, the coal mill 3 is used for mixing and grinding coal, water and additives to form coal slurry, the coal slurry tank 6 is used for storing the coal slurry, the coal slurry feeding pump 7 is used for conveying the coal slurry in the coal slurry tank 6 to an additive separation unit 8, the additive separation unit 8 is used for destroying the adsorption connection relationship between the additives and coal particles, a dewatering unit 9 is used for separating the water dissolved with the additives in the coal slurry passing through the additive separation unit 8, the dewatering unit 9 is provided with a water outlet and a coal outlet, the water outlet is connected with the collecting tank 12, and the coal outlet is connected with the gasification furnace 11 through a gasification burner 10.

Compared with the prior art, the additive separation unit 8 and the water removal unit 9 are arranged between the pulping and conveying unit and the gasification furnace 11, the additive separation unit 8 is adopted to destroy the adsorption connection relationship between the additive and the coal particles, so that the additive is dissolved in water, then the water dissolved with the additive is separated from the coal particles through the water removal unit 9, the coal particles enter the gasification furnace 11 for gasification reaction, the water is separated, the water is prevented from entering the gasification furnace 11 to be evaporated, the heat in the gasification furnace 11 is occupied, the additional energy consumption is avoided, the temperature in the gasification furnace 11 is maintained, the water dissolved with the additive is collected through the collection tank 12, the additive is recovered, the additive can be reused, and the gasification cost of the coal water slurry is saved.

The additive separation unit 8 can increase the solubility of the additive in water by heating or adding a displacing agent, destroy the adsorption connection relationship between the additive and the coal particles, and finally dissolve the additive in water.

The water removal unit 9 may be implemented by means of a flash tank, reverse osmosis, hydrocyclone or the like, preferably a hydrocyclone. The overflow port at the upper part of the hydrocyclone is a water outlet, and the lower port of the hydrocyclone is a coal outlet; it is within the ability of one skilled in the art to effect separation of water and coal from the coal-water slurry in the manner described above.

In some embodiments, as shown in fig. 1, the additive separation unit 8 comprises a body for displacing the additive with the displacing agent, and a displacing agent delivery pump 15, an outlet of the displacing agent delivery pump 15 being connected to the body. The water-soluble displacing agent is an inorganic organic matter which can be adsorbed on the surfaces of coal particles to displace the additive, the existing coal water slurry additive mostly adopts lignosulfonate anionic surfactant, the corresponding displacing agent can adopt inorganic solution with low cost such as sodium carbonate, sodium hydroxide, calcium hydroxide and the like, the displacing agent is pumped into the body by the displacing agent delivery pump 15 to be mixed with the coal water slurry, and thus the additive is displaced into water from the surfaces of the coal particles.

Further, as shown in fig. 1 and fig. 2, the body includes an inner cylinder 81 and an outer cylinder 82 which are coaxially arranged, the outer cylinder 82 is provided with a steam inlet 83 and a condensate outlet 84, the coal slurry feeding pump 7 pumps the coal slurry into the inner cylinder 81 through a coal slurry inlet 85, the displacer delivery pump 15 pumps the displacer into the inner cylinder 81 through a displacer inlet 86, and after the additive and the coal particles are dissolved in water after being separated from the adsorption connection relationship, the coal slurry flows to the water removal unit 9 through a coal slurry outlet 87. Hot steam is introduced into a space between the outer cylinder 82 and the inner cylinder 81 through the steam inlet 83, so that the coal water slurry in the inner cylinder 81 is heated, the stability of the coal slurry is favorably reduced, the solubility of the additive in water is increased, the stability of coal particles is poor due to the increase of the temperature, the coal water slurry is further settled, and the coal water slurry is conveniently separated in the dewatering unit 9; those skilled in the art can also use steam removal to heat the inner cylinder 81, such as an electric heating device disposed in the inner cylinder 81 or a boiler directly used to heat the inner cylinder 81.

As a preferred embodiment, the additive adopts sodium polystyrene sulfonate or sodium lignin sulfonate, the temperature in the inner cylinder 81 is controlled to be 100-150 ℃, the structure of the sodium polystyrene sulfonate or sodium lignin sulfonate is easy to damage due to overhigh temperature, and the recycling of the recycled additive is not facilitated.

In some embodiments, as shown in fig. 1 and 2, an agitating unit 88 is further disposed within the inner cylinder 81. The stirring unit 88 increases the mixing uniformity of the displacing agent and the coal water slurry, ensures that the additive is more easily contacted with the displacing agent to react, and the displaced additive can be completely dissolved in water.

In some embodiments, as shown in fig. 1, the system further comprises a pressure reduction unit 13 and a buffer tank 14, and the collection tank 12 is connected with the buffer tank 14 through the pressure reduction unit 13. The pressure reducing unit 13 can adopt a pressure reducing valve, the buffer tank 14 can adopt a flash tank, the water dissolved with the additives firstly enters the collecting tank 12, then enters the flash tank after being reduced in pressure by the pressure reducing valve, the steam of the flash is discharged, the water solution dissolved with the additives is concentrated in the flash tank, and finally the water solution dissolved with the additives can be recovered by the flash tank and also can be conveyed to the coal mill 3 through the flash tank to be recycled as the feed of the additives.

In some embodiments, as shown in fig. 1, a coal bunker 1 and a coal weigh feeder 2 are also included, the coal weigh feeder 2 being used to transport coal from the coal bunker 1 to a coal pulverizer 3. The coal bunker 1 is a raw coal storage device, and the coal weighing feeder 2 is a conveying device.

In some embodiments, as shown in fig. 1, the coal slurry discharging tank 4 and the coal slurry discharging tank pump 5 are further included, the coal slurry discharging tank 4 is disposed at a discharging port of the coal pulverizer 3, and the coal slurry discharging tank pump 5 is used for conveying the coal water slurry from the coal slurry discharging tank 4 to the coal slurry tank 6.

In some embodiments, an additive replenishing device is further included, and the additive replenishing device is connected with the coal mill 3, and when the additive amount is reduced after circulation or the additive addition amount needs to be increased, the additive is provided to the coal mill 3 through the additive replenishing device and the buffer tank 14.

The invention also provides a method for recovering the coal water slurry additive, which comprises the following steps:

A. the coal mill 3 mixes and grinds coal, water and additives to form coal water slurry, and the coal water slurry is stored in a coal slurry tank 6;

B. pumping the coal water slurry from the coal slurry tank 6 to the additive separation unit 8 by the coal slurry feeding pump 7, and destroying the adsorption connection relationship between the additive and the coal particles by the additive separation unit 8 so as to dissolve the additive in water; a displacer delivery pump 15 is adopted to deliver the displacer to the additive separation unit 8, simultaneously, the coal water slurry in the additive separation unit 8 is heated, and the displacer displaces the additive from the surface of the coal particles to water so that the additive is dissolved in the water;

C. the water coal slurry with the additive separated is subjected to water separation by a water removal unit 9, wherein the additive is dissolved in the water coal slurry;

D. the separated water dissolved with the additive is recycled through the step of recycling the additive, and the coal water slurry with part of water removed enters the gasification furnace 11 to carry out gasification reaction; the separated water with the dissolved additives firstly enters a collecting tank 12 and then enters a buffer tank 14 through a pressure reducing unit 13, and the buffer tank 14 is connected with the coal mill 3 to provide the additives for the coal mill 3 and can also provide the additives for the coal mill 3 through an additive supplementing device.

One embodiment of the present invention is as follows:

after a gate valve at the bottom of the coal bunker 1 is opened, pulverized coal continuously enters the coal weighing feeder 2 from a discharge port at the bottom, and a path of low-pressure nitrogen is introduced into the lower half part of the coal bunker 1 so as to prevent coal in the coal bunker 1 from spontaneous combustion;

the mass flow of the coal powder entering a coal mill 3 is determined by setting the belt speed of a coal weighing feeder 2, meanwhile, water and additive sodium polystyrene sulfonate are metered by a flowmeter 16 and flow into the coal mill 3, after being mixed and ground by the coal mill 3, the coal water slurry with the average particle size of about 100 microns flows into a coal slurry discharge chute 4, the concentration of the coal water slurry is 60 percent (wt), and the concentration of the sodium polystyrene sulfonate is 1 percent (wt);

the coal slurry discharging tank 4 is provided with a stirrer and is used for preventing coal particles in the coal water slurry from settling; the discharge hole at the bottom of the coal slurry discharge tank 4 is required to be at a certain height from the ground, and in order to ensure the inlet pressure of the coal slurry discharge tank pump 5, the coal slurry discharge tank pump 5 conveys the coal water slurry into a coal slurry tank 6;

the discharge hole at the bottom of the coal slurry tank 6 also needs to be at a certain height from the ground, and in order to ensure the inlet pressure of the coal slurry feeding pump 7, the coal slurry feeding pump 7 conveys the coal water slurry to the inner cylinder 81;

pressurizing a sodium bicarbonate solution with the concentration of 25% (wt) by a displacer delivery pump 15, then feeding the sodium polystyrene sulfonate as an additive in the coal water slurry into an inner cylinder 81, introducing hot steam into a space between an outer cylinder 82 and the inner cylinder 81 through a steam inlet 83, heating the coal water slurry in the inner cylinder 81 to about 120 ℃ from the normal temperature, providing a certain pressure for the inner cylinder 81 by a coal slurry feed pump 7 and the displacer delivery pump 15, pushing the displaced and heated coal water slurry into a water removal unit 9 by the pressure, fully mixing the separated and concentrated coal water slurry with oxygen by a gasification burner 10, and feeding atomized coal particles into a gasification furnace for reaction; the removed water dissolved with the sodium polystyrene sulfonate is also pushed to the collecting tank 12 by pressure, the recovery rate of the sodium polystyrene sulfonate is 75-90%, the water dissolved with the sodium polystyrene sulfonate flows into the buffer tank 14 after being decompressed by the decompression valve, simultaneously, the steam flashed out is emptied, the pressure of the decompressed buffer tank 14 is 0.2-0.6 MPa, the concentration of the sodium polystyrene sulfonate is 15-40%, the water dissolved with the sodium polystyrene sulfonate in the flash tank is mixed with the additive supplemented by the additive supplementing device, and then the mixture flows into the coal mill 3 after being metered by the flowmeter 16, so that the recycling of the additive sodium polystyrene sulfonate is realized.

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