CN116376604A - Crude synthesis gas separation and purification equipment and method - Google Patents

Abstract

The invention relates to a crude synthesis gas separation and purification device and a method, wherein a gas-solid separator is integrated in a washing tower, so that the gas-solid separator and the washing tower share a liquid phase region, gas output by the gas-solid separator can be directly distributed at one time through an outlet of the gas-solid separator, and then is secondarily distributed through a tower plate in the process of contacting with liquid, thereby greatly reducing the arrangement of pipelines and corresponding detection devices, obviously shortening the process flow, avoiding the problem of secondary back mixing of solid particles in the sedimentation process, realizing continuous separation and purification of gas and solid, and being beneficial to improving the separation efficiency; the integrated separation and purification equipment has compact structure, small occupied space, low device investment and better reliability.

Description

Crude synthesis gas separation and purification equipment and method

Technical Field

The invention relates to the technical field of gas-solid (liquid) separation, in particular to separation and purification equipment and method for dust-containing crude synthesis gas in the field of coal chemical industry.

Background

Coal is a main energy source and an important chemical raw material in China. Coal gasification technology is the basis of modern coal chemical industry and is an important direction for clean and efficient utilization of coal. The coal is gasified at high temperature to prepare crude synthesis gas, and the crude synthesis gas produced from the gasifier contains a large amount of solid particles, so that the gas-solid separation is needed to be further carried out in order to improve the cleanliness of the crude synthesis gas and ensure smooth and stable operation of the following procedures.

The Chinese patent application No. CN105062574A discloses a scheme, which is consistent with the traditional technical conception, of a high-efficiency combined dust-containing synthetic gas washing and dedusting device and a method thereof (application No. CN 201510544879.0), wherein dust-containing crude synthetic gas produced from a gasification furnace firstly enters a cyclone separator for gas-solid separation, large-particle solids are separated, the separated gas enters a water washing tower for washing through pipeline connection, and fine ash is further separated, namely, gas-solid separation and washing are respectively realized by two devices. In the scheme, the cyclone separator and the water washing tower are respectively and independently arranged, occupy two-span structure frames, and are required to be connected with two devices through pipelines, so that the defects of long flow, large number of devices, large occupied area, high equipment investment and the like, which are caused by the need of configuring related instruments and connecting pipelines, are overcome; in addition, the ash discharge port of the traditional cyclone separator is easy to be blocked, and solid particles are easy to generate secondary back mixing in the sedimentation process, so that gas-solid separation is incomplete.

Therefore, there is a need for further improvements in the current crude synthesis gas separation and purification technology.

Disclosure of Invention

The first technical problem to be solved by the invention is to provide the crude synthesis gas separation and purification equipment which has the advantages of compact equipment structure, small occupied space, low device investment and capability of avoiding secondary back mixing of solid particles in the sedimentation process, aiming at the current state of the art.

The second technical problem to be solved by the invention is to provide a crude synthesis gas separation and purification method which is short in process flow and capable of realizing continuous separation and purification of gas and solid so as to improve separation efficiency aiming at the current state of the art.

The invention solves at least one of the technical problems by adopting the following technical proposal:

the crude synthesis gas separation and purification equipment comprises a washing tower and a gas-solid separator, wherein the inner cavity of the washing tower is divided into an upper part and a lower part, a tower plate and a cyclone foam remover which are arranged from bottom to top are arranged in the upper part, a synthesis gas outlet is arranged at the top of the washing tower, and a washing liquid inlet pipe for inputting washing liquid into an upper layer tower plate and a gray water inlet pipe for inputting washing gray water into a middle layer tower plate are arranged on the side wall of the upper part of the washing tower;

the gas-solid separator is arranged in the lower part of the inner cavity of the washing tower, gas inlet pipes for crude synthesis gas to be input into the gas-solid separator are arranged on the side walls of the washing tower and the gas-solid separator, a gas outlet is formed in the top of the gas-solid separator, the bottom of the washing tower is used for containing the washed black water, an ash discharge port extending to the position below the black water liquid level is formed in the bottom of the gas-solid separator, and a downcomer extending to the position below the black water liquid level is connected with a lower column plate; the bottom of the washing tower is provided with a black water outlet.

Preferably, a gas distributor for gas dispersion output is connected at a gas outlet at the top of the gas-solid separator. The gas distributor comprises a central tube connected with a gas outlet of the gas-solid separator and a distribution tube transversely connected to the top of the central tube, wherein the gas outlet on the distribution tube is positioned at the end part of the distribution tube and is arranged downwards, and the gas outlet is arranged corresponding to the bottom of the lowest layer of tower plate. The structure can improve the gas distribution effect, and the direction of the gas outlet is downward, which is opposite to the movement direction of the gas in the washing tower, so that the gas-liquid phase contact probability is increased, and the washing efficiency is improved.

Preferably, the opening angle of the gas outlet on the distributing pipe of the gas distributor is 45-170 degrees.

Preferably, the lower part of the gas-solid separator is formed into a conical part with gradually reduced diameter from top to bottom, the ash discharge port extends downwards from the lower end of the conical part, a washing ash water inlet which penetrates through the side wall of the gas-solid separator and faces to spray washing liquid is arranged at the side part of the washing tower, and the washing ash water inlet is positioned at the joint of the conical part and the ash discharge port.

Preferably, black water at the bottom of the washing tower is subjected to primary clarification by a downstream black water treatment system to obtain grey water, and the grey water is pressurized by a water pump and then recycled in two parts. Part of the water is used as washing ash water and enters a tray through an inlet of the washing tower; the other part is used as washing ash water, and enters the gas-solid separator through the washing ash water inlet. The gray water is recycled, so that the consumption of clean washing water can be reduced, and the black water treatment capacity can be reduced. In order to facilitate the production of the manufacturing equipment, the gas-solid separator is welded to the inner wall of the scrubber by means of a connection piece of its side wall. The gas inlet pipe, the ash discharge port and the inner wall of the washing tower of the gas-solid separator are provided with wear-resistant linings.

A method for separating and purifying crude synthesis gas, comprising the following steps:

step S1: the dust-containing crude synthesis gas is discharged from the gasification furnace, enters a gas-solid separator along the tangential direction through a gas inlet pipe and is centrifugally separated;

step S2: large solid particles are settled under the action of centrifugal force and gravity, and meanwhile, the ash water is injected from an ash water inlet pipe, so that on one hand, the solid particles can be wetted, part of solid particles entrained by gas are washed away, the secondary back mixing of the solid particles under the entrainment of ascending airflow in the settling process is avoided, and the separation effect is improved; on the other hand, the ash discharge port is washed, so that the ash discharge port is prevented from being blocked, and the gas-solid separation efficiency is influenced; the turbid liquid with high solid content is discharged from an ash discharge port at the bottom of the gas-solid separator and enters a liquid phase zone at the bottom of the washing tower;

step S3: the gas subjected to primary separation is discharged from a gas outlet at the upper part of the gas-solid separator, enters a gas distributor, and enters a distribution pipe through a central pipe to realize primary distribution of the gas; the outlet direction of the gas distributor is downward, and is opposite to the movement direction of the gas in the washing tower, so that the secondary distribution of the gas is realized, the contact probability of the gas and the liquid is increased, and the washing efficiency is improved;

step S4: the gas from the gas distributor enters the gas phase zone of the washing tower, flows from bottom to top and passes through the multi-layer tower plates; firstly, the dirty crude synthesis gas is contacted with washing ash water entering a tower plate from the middle part of the tower, and then moves upwards continuously after being subjected to preliminary washing, and is reversely contacted with clean washing liquid entering the upper part of the tower, so that the purity of the crude synthesis gas at an outlet is ensured. Washing in two washing water sections, enabling the two washing water sections to flow from top to bottom, enabling the gas phase and the liquid phase to be in full reverse contact, washing out most of fine ash in the gas phase, and enabling the washed turbid liquid to directly enter a liquid phase zone at the bottom of the tower through a downcomer;

step S5: the washed crude synthetic gas is discharged from a synthetic gas outlet at the top of the washing tower to enter the next process after entrained liquid is removed by a cyclone plate demister, and all turbid liquid is discharged from a black water outlet together to enter a black water treatment system to be treated in the next process.

Compared with the prior art, the invention has the advantages that: the gas-solid separator is integrated in the washing tower, so that the gas-solid separator and the washing tower share a liquid phase region, the gas output by the gas-solid separator can be directly distributed once through the outlet of the gas-solid separator, and then is secondarily distributed through the tower plate in the process of contacting with liquid, thereby greatly reducing the arrangement of pipelines and corresponding detection devices, obviously shortening the process flow, avoiding the problem of secondary back mixing of solid particles in the sedimentation process, realizing continuous separation and purification of gas and solid, and being beneficial to improving the separation efficiency; the integrated separation and purification equipment has compact structure, small occupied space, low device investment and better reliability.

Drawings

FIG. 1 is a schematic diagram of a crude synthesis gas separation and purification apparatus in accordance with an embodiment of the present invention;

FIG. 2 is a cross-sectional view taken along the line A-A in FIG. 1;

FIG. 3 is a cross-sectional view of a gas outlet on a distribution pipe according to an embodiment of the present invention;

FIG. 4 is a process flow diagram of a crude synthesis gas separation and purification process according to an embodiment of the invention.

Detailed Description

The invention is described in further detail below with reference to the embodiments of the drawings.

As shown in fig. 1 to 3, the crude synthesis gas separation and purification device of the present embodiment comprises a washing tower 1 and a gas-solid separator 3, wherein the inner cavity of the washing tower 1 is divided into an upper part and a lower part, a tower plate 12 and a cyclone foam remover 14 which are arranged from bottom to top are arranged in the upper part, a synthesis gas outlet 11 is arranged at the top of the washing tower 1, and a washing liquid inlet pipe 13 for inputting washing liquid into the upper layer tower plate 12 and a grey water inlet pipe 18 for inputting washing grey water into the lower layer tower plate 12 are arranged on the side wall of the upper part of the washing tower 1; the gas-solid separator 3 is arranged in the lower part of the inner cavity of the washing tower 1, gas inlet pipes 32 for inputting crude synthesis gas into the gas-solid separator 3 are arranged on the side walls of the washing tower 1 and the gas-solid separator 2, a gas outlet 31 is formed in the top of the gas-solid separator 3, the bottom of the washing tower 1 is used for containing washed black water, an ash discharge port 35 extending below the black water liquid level 16 is formed in the bottom of the gas-solid separator 3, a downcomer 15 extending below the black water liquid level is connected with a lower column plate 12, and the gas-solid separator 3 and the washing tower 1 share a liquid phase area; the bottom of the washing tower 1 is provided with a black water outlet 17.

A gas distributor 2 for gas dispersion output is connected at a gas outlet 31 at the top of the gas-solid separator 3. The gas distributor 2 comprises a central tube 21 connected with gas outlets 31 and a distribution tube 22 transversely connected to the top of the central tube 21, wherein blind flanges or tube caps 23 are arranged at the tail ends of the distribution tube 22, the gas outlets on the distribution tube 22 are positioned at the end parts of the distribution tube 22 and are arranged downwards, and the gas outlets are arranged corresponding to the bottom of the lowest column plate. The structure can improve the gas distribution effect, and the direction of the gas outlet is downward, which is opposite to the movement direction of the gas in the washing tower 1, so that the gas-liquid contact probability is increased, and the washing efficiency is improved.

The opening angle theta corresponding to the gas outlet on the gas distributor is 45-170 degrees.

The lower part of the gas-solid separator 3 is formed into a conical part with gradually reduced diameter from top to bottom, the ash discharge port extends downwards from the lower end of the conical part, a washing ash water inlet 34 which penetrates through the side wall of the gas-solid separator 3 and faces to spray washing liquid is arranged on the side part of the washing tower 1, and the washing ash water inlet 34 is positioned at the joint of the conical part and the ash discharge port 35.

In order to facilitate the production of the manufacturing equipment, the gas-solid separator 3 is welded to the inner wall of the scrub column 1 by means of a connecting piece 33 of its side wall. The gas inlet pipe 32, the ash discharge port 35 and the inner wall of the washing tower 1 of the gas-solid separator 3 are provided with wear-resistant linings.

As shown in fig. 1 to 4, the crude synthesis gas separation and purification method of the embodiment includes the steps of:

step S1: the dust-containing crude synthesis gas is discharged from the gasification furnace 4 and enters the gas-solid separator 3 in a tangential direction through the gas inlet pipe 32 for centrifugal separation;

step S2: large solid particles are settled under the action of centrifugal force and gravity, and meanwhile, the ash water is injected from an ash water inlet pipe 34, so that on one hand, the solid particles can be wetted, part of solid particles entrained by gas can be washed away, the secondary back mixing of the solid particles under the entrainment of ascending air flow in the settling process is avoided, and the separation effect is improved; on the other hand, the ash discharge port is washed, so that the ash discharge port is prevented from being blocked, and the gas-solid separation efficiency is influenced; the turbid liquid with high solid content is discharged from an ash discharge port 35 at the bottom of the gas-solid separator and enters a liquid phase zone at the bottom of the washing tower;

step S3: the gas which is primarily separated is discharged from a gas outlet 31 at the upper part of the gas-solid separator and enters a gas distributor 2, and the gas enters a distribution pipe 22 through a central pipe 21 to realize primary distribution of the gas; the outlet direction of the gas distributor 2 is downward, and is opposite to the movement direction of the gas in the washing tower 1, so that the secondary distribution of the gas is realized, the contact probability of the gas and the liquid is increased, and the washing efficiency is improved;

step S4: the gas from the gas distributor 2 enters the gas phase region of the washing tower 1, flows from bottom to top and passes through the multi-layer tower plate 12; washing liquid enters the tower tray from the upper inlet 13 of the tower, washing ash water enters the tower tray from the ash water inlet pipe 18 in the middle of the tower under the power of the pump 6, flows from top to bottom, and is in full reverse contact with the gas phase and the liquid phase to wash most of fine ash in the gas phase, and the washed turbid liquid directly enters the liquid phase zone at the bottom of the tower through the downcomer 15;

step S5: the washed crude synthesis gas is discharged from a synthesis gas outlet 11 at the top of the washing tower 1 to enter the next process after entrained liquid is removed by a cyclone plate demister 14, and all turbid liquid is discharged from a black water outlet 17 together to enter a black water treatment system 5 for the next process.

In the embodiment, the gas-solid separator 3 is integrated in the washing tower 1, so that the gas-solid separator 3 and the washing tower 1 share a liquid phase region, gas output by the gas-solid separator 3 can be directly distributed once through an outlet of the gas-solid separator 3, and then secondarily distributed through the tower plate 12 in the process of contacting with liquid, thereby greatly reducing the arrangement of pipelines and corresponding detection devices, obviously shortening the process flow, avoiding the problem of secondary back mixing of solid particles in the sedimentation process, realizing continuous separation and purification of gas and solid, and being beneficial to improving the separation efficiency; the integrated separation and purification equipment has compact structure, small occupied space, low device investment and better reliability.

In the description and claims of the present invention, terms indicating directions, such as "front", "rear", "upper", "lower", "left", "right", "side", "top", "bottom", etc., are used to describe various example structural parts and elements of the present invention, but these terms are used herein for convenience of description only and are determined based on the example orientations shown in the drawings. Because the disclosed embodiments of the invention may be arranged in a variety of orientations, the directional terminology is used for purposes of illustration and is in no way limiting, such as "upper" and "lower" are not necessarily limited to being in a direction opposite or coincident with the direction of gravity.

Claims (8)

1. The utility model provides a crude synthesis gas separation clarification plant, includes scrubbing tower and gas-solid separator, its characterized in that: the inner cavity of the washing tower is divided into an upper part and a lower part, a tower plate and a cyclone foam remover which are arranged from bottom to top are arranged in the upper part, a synthetic gas outlet is arranged at the top of the washing tower, and a washing liquid inlet pipe for inputting washing liquid into the upper layer tower plate and a gray water inlet pipe for inputting washing gray water into the lower layer tower plate are arranged on the side wall of the upper part of the washing tower;

the gas-solid separator is arranged in the lower part of the inner cavity of the washing tower, gas inlet pipes for crude synthesis gas to be input into the gas-solid separator are arranged on the side walls of the washing tower and the gas-solid separator, a gas outlet is formed in the top of the gas-solid separator, the bottom of the washing tower is used for containing the washed black water, an ash discharge port extending to the position below the black water liquid level is formed in the bottom of the gas-solid separator, and a downcomer extending to the position below the black water liquid level is connected with a lower column plate; the bottom of the washing tower is provided with a black water outlet.

2. The raw synthesis gas separation and purification plant according to claim 1, wherein: and a gas distributor for gas dispersion output is connected at a gas outlet at the top of the gas-solid separator.

3. The raw synthesis gas separation and purification plant according to claim 2, wherein: the gas distributor comprises a central tube connected with the gas outlets and a distribution tube transversely connected to the top of the central tube, the gas outlets on the distribution tube are positioned at the end part of the distribution tube and are arranged downwards, and the gas outlets are arranged corresponding to the bottom of the lowest layer of tower plate.

4. A raw synthesis gas separation and purification plant according to claim 3, wherein: the opening angle corresponding to the gas outlet on the gas distributor is 45-170 degrees.

5. The raw synthesis gas separation and purification apparatus according to any one of claims 1 to 4, wherein: the lower part of the gas-solid separator is formed into a conical part with gradually reduced diameter from top to bottom, the ash discharge port extends downwards from the lower end of the conical part, a washing ash water inlet which penetrates through the side wall of the gas-solid separator and faces to spray washing liquid is arranged at the side part of the washing tower, and the washing ash water inlet is positioned at the joint of the conical part and the ash discharge port.

6. The raw synthesis gas separation and purification apparatus according to any one of claims 1 to 4, wherein: the gas-solid separator is welded on the inner wall of the washing tower through a connecting piece on the side wall of the gas-solid separator.

7. The raw synthesis gas separation and purification apparatus according to any one of claims 1 to 4, wherein: the gas inlet pipe, the ash discharge port and the inner wall of the washing tower of the gas-solid separator are provided with wear-resistant linings.

8. The crude synthesis gas separation and purification method is characterized by comprising the following steps:

step S1: the dust-containing crude synthesis gas is discharged from the gasification furnace, enters a gas-solid separator along the tangential direction through a gas inlet pipe and is centrifugally separated;

step S2: large solid particles are settled under the action of centrifugal force and gravity, and meanwhile, the ash water is injected from an ash water inlet pipe, so that on one hand, the solid particles can be wetted, part of solid particles entrained by gas can be washed away, and secondary back mixing of the solid particles under the entrainment of ascending airflow in the settling process is avoided; on the other hand, the ash discharge port is washed, so that the ash discharge port is prevented from being blocked; the turbid liquid with high solid content is discharged from an ash discharge port at the bottom of the gas-solid separator and enters a liquid phase zone at the bottom of the washing tower;

step S3: the gas subjected to primary separation is discharged from a gas outlet at the upper part of the gas-solid separator, enters a gas distributor, and enters a distribution pipe through a central pipe to realize primary distribution of the gas; the outlet direction of the gas distributor is downward, and is opposite to the movement direction of the gas in the washing tower, so that the secondary distribution of the gas is realized, and the contact probability of the gas and the liquid is increased;

step S4: the gas from the gas distributor enters the gas phase zone of the washing tower, flows from bottom to top and passes through the multi-layer tower plates; washing liquid enters a tray from an inlet at the upper part of the tower, washing ash water enters the tray from an ash water inlet pipe at the middle part of the tower, flows from top to bottom, and is in full reverse contact with gas-liquid two phases, so that most of fine ash in the gas phase is washed off, and the washed turbid liquid directly enters a liquid phase zone at the bottom of the tower through a downcomer;

step S5: the washed crude synthetic gas is discharged from a synthetic gas outlet at the top of the washing tower to enter the next process after entrained liquid is removed by a cyclone plate demister, and all turbid liquid is discharged from a black water outlet together to enter a black water treatment system to be treated in the next process.

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