Comprehensive treatment device and treatment method for flash steam

Abstract

The invention discloses a comprehensive treatment device and method for flash steam, and belongs to the technical field of flash steam treatment. The comprehensive treatment device for the flash steam comprises a high-pressure flash tank and a low-pressure flash tank which are connected in sequence, a high-flash gas outlet pipe is arranged at a gas outlet of the high-pressure flash tank, the high-flash gas outlet pipe is connected with a stripping tower through a high-flash purification structure, and the high-flash gas outlet pipe is connected with a deaerator through a high-flash ventilation pipe; a gas outlet of the low-pressure flash tank is connected with the deaerator through a low-flash gas outlet pipe, a liquid outlet of the stripping tower is connected with the deaerator, and the deaerator is connected with the high-flash purification structure through a deoxidizing water pipe. By adopting the comprehensive treatment device and the treatment method of the flash steam, the problems that the flash steam is easy to cause the blockage of the stripping tower and the sulfur recovery is influenced can be solved.

Description

Technical Field

[0001] The present invention relates to the technical field of flash steam treatment, and in particular to a comprehensive treatment device and method for flash steam. Background Art

[0002] The low-pressure flash steam (low flash gas) of the water-coal slurry and pulverized coal pressurized gasification device is generally sent to the slag water deaerator, and used together with the low-pressure steam as the heat source of the deaerator. The heat and steam contained in the low flash gas are recovered through the deaerator, and the non-condensable gas discharged from the deaerator is sent to the sulfur recovery device. The normal process of high-pressure flash steam (high flash gas) in gasification slag water treatment is to send it to the conversion stripping tower. The stripping tower uses high-pressure flash steam and low-pressure steam as heat sources. The wet acid gas discharged from the stripping tower is then sent to the desulfurization recovery device. For a long time, wet acid gas has a great impact on the operation of the sulfur recovery device, resulting in the environmental protection facilities of most coal chemical enterprises not being able to operate smoothly. Because the high flash gas contains a certain amount of ash and moisture, it is easy to cause the stripping tower tray to be blocked and the pressure difference to rise. Sometimes all the high flash gas has to be sent to the flare through the pressure control valve for combustion, which creates environmental protection problems and also has certain hazards to the safe and stable operation of the flare system. Summary of the invention

[0003] The object of the present invention is to provide a comprehensive flash steam treatment device and method to solve the problem that flash steam easily causes stripping tower blockage and affects sulfur recovery.

[0004] To achieve the above-mentioned purpose, the present invention provides a comprehensive treatment device for flash steam, comprising a high-pressure flash tank and a low-pressure flash tank connected in sequence, the gas outlet of the high-pressure flash tank is provided with a high-flash gas outlet pipe, the high-flash gas outlet pipe is connected to a stripping tower through a high-flash purification structure, the high-flash gas outlet pipe is connected to a deaerator through a high-flash ventilation pipe, the gas outlet of the low-pressure flash tank is connected to the deaerator through a low-flash gas outlet pipe, the liquid outlet of the stripping tower is connected to the deaerator, and the deaerator is connected to the high-flash purification structure through a deoxygenation water pipe.

[0005] Preferably, the high flash purification structure includes a saturated hot water tower, the gas outlet of the high-pressure flash tank is connected to the saturated hot water tower through a high flash outlet pipe, the gas outlet of the saturated hot water tower is connected to the gas-water separator through a cooling pipe, the gas-water separator is connected to the gas inlet of the stripping tower or / and the flare through the gas outlet pipe, the liquid outlet of the gas-water separator is connected to the deaerator; the deoxygenation water pipe is connected to the liquid inlet of the saturated hot water tower, and a deoxygenation pump is provided on the deoxygenation water pipe.

[0006] Preferably, a high flash cooler is provided on the cooling pipe.

[0007] Preferably, the low flash exhaust pipe is connected to the stripping tower via a low flash vent pipe.

[0008] Preferably, the saturated hot water tower is segmented with an intermediate tower plate and an upper tower plate, the upper tower plate is located above the intermediate tower plate, the deoxygenated water pipe is connected to the liquid inlet of the intermediate tower plate, and the liquid inlet of the upper tower plate is connected to the desalted water.

[0009] Preferably, the stripping tower comprises a packing layer, a condensation layer and a spray layer arranged in sequence from bottom to top, the gas outlet of the low-flash vent pipe on the stripping tower and the gas outlet of the gas-water separator are both located below the packing layer, a steam inlet is arranged below the packing layer, an acid condensate inlet is arranged between the packing layer and the condensation layer, an ammonia water outlet is arranged below the condensation layer, desalted water is passed into the condensation layer, desalted water is passed into the spray layer, and the gas outlet at the top of the stripping tower is connected to a sulfur recovery device and / or a flare.

[0010] Preferably, a condenser is provided at the gas outlet of the deaerator, and the gas is sent to the sulfur recovery device through the condenser.

[0011] The processing method based on the above-mentioned comprehensive processing device of flash steam comprises the following steps: S1, the gasified black water enters the high-pressure flash tank for high-pressure flash evaporation, and the black water after high-pressure flash evaporation enters the low-pressure flash tank through the bottom liquid outlet of the high-pressure flash tank for further flash evaporation, and the black water after low-pressure flash evaporation is discharged to the true flash through the bottom liquid outlet; S2. The gas in the high-pressure flash tank enters the saturated hot water tower through the top outlet, the deoxygenated water in the deaerator enters the middle tower plate of the saturated hot water tower through the deoxygenation pump, and the desalted water enters the upper tower plate of the saturated hot water tower. The high-flash gas is purified by the deoxygenated water and the desalted water; the gas in the high-pressure flash tank enters the deaerator through the high-flash vent pipe to provide heat energy for the deaerator; S3, the liquid in the saturated hot water tower goes to the high-pressure ash water pump, the gas in the saturated hot water tower enters the high flash cooler through the cooling pipe for cooling, and then is sent to the gas-water separator for gas-water separation, the separated gas is sent to the stripping tower and / or the flare, and the separated liquid is sent to the deaerator for liquid replenishment; S4. The gas in the low-pressure flash tank enters the deaerator through the low-flash outlet pipe to provide heat energy for the deaerator; the low-flash gas in the low-flash outlet pipe enters the stripping tower through the low-flash vent pipe for treatment; S4. The high flash gas and low flash gas entering the stripping tower are treated through the packing layer, and are cooled by the condensation layer and the spray layer, and then discharged from the top of the stripping tower to the desulfurization recovery device or / flare; the acid condensate entering the stripping tower is treated by the packing layer and then discharged into the deaerator together with the condensed steam through the drain pipe for liquid replenishment; the steam in the deaerator further treats the acid condensate, and the treated gas is condensed by the condenser through the exhaust port and then discharged to the desulfurization recovery device.

[0012] The advantages and positive effects of the comprehensive flash steam treatment device and treatment method of the present invention are: 1. In the present invention, the saturated hot water tower is provided with liquid inlets in sections, the liquid inlet of the middle tower plate is deoxygenated water, and the liquid inlet of the uppermost tower plate is clean cold desalted water. The desalted water significantly enhances the washing effect of high flash gas, and the high flash gas is not prone to blockage after entering the stripping tower.

[0013] 2. The present invention introduces part of the high flash gas into the water tank of the deaerator. Since the temperature of the high flash gas is higher than that of the low flash gas and the low-pressure steam, the steam consumption of the deaerator is reduced while washing the high flash gas, and the circulating water load of the high flash cooler is also reduced.

[0014] 3. The present invention sets a spray layer on the top of the stripping tower. When the stripping gas passes through the condensation section, the steam and gaseous ammonia are partially condensed, and then the ammonia and steam are further absorbed by the upper cool desalted water spray, thereby reducing the temperature of the gas entering the sulfur recovery device and alleviating the problem of crystallization blocking the pipeline; the acid gas vapor content is reduced, which is conducive to ensuring the stable operation of sulfur recovery.

[0015] 4. Low flash gas is cleaner than high flash gas. Passing part of the low flash gas into the stripping tower can reduce the steam consumption of the stripping tower and achieve energy saving.

[0016] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of a saturated hot water tower according to an embodiment of the present invention; Figure 3 Schematic diagram of the stripping tower structure of an embodiment of the present invention.

[0018] Reference numerals 1. High-pressure flash tank; 2. Low-pressure flash tank; 3. Saturated hot water tower; 4. High-pressure flash cooler; 5. Gas-water separator; 6. Stripping tower; 7. Deaerator; 8. Deaerator pump; 9. High-pressure flash outlet pipe; 10. High-pressure flash ventilation pipe; 11. Low-pressure flash outlet pipe; 12. Low-pressure flash ventilation pipe; 13. Cooling pipe; 14. Drain pipe; 15. Deaerator water pipe; 16. Packing layer; 17. Condensation layer; 18. Spray layer. DETAILED DESCRIPTION

[0019] In the description of the present invention, it should be noted that the terms "upper", "lower", "inside", "outside", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the invented product is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In the description of the present invention, it should also be noted that, unless otherwise clearly specified and limited, the terms "setting", "installation", and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0020] The embodiments of the present invention are described in detail below in conjunction with the accompanying drawings.

[0021] like Figure 1 A comprehensive flash steam treatment device comprises a high-pressure flash tank 1 and a low-pressure flash tank 2 connected in sequence, wherein the liquid outlet of the high-pressure flash tank 1 is connected to the liquid inlet of the low-pressure flash tank 2, and the high-pressure flash tank 1 and the low-pressure flash tank 2 sequentially treat black water. The black water treated by the low-pressure flash tank 2 is discharged through the bottom liquid outlet for true flash treatment.

[0022] The gas outlet of the high-pressure flash tank 1 is provided with a high-flash gas outlet pipe 9, which is connected to the stripping tower 6 through a high-flash purification structure. The high-flash gas outlet pipe 9 is connected to the deaerator 7 through a high-flash ventilation pipe 10. A part of the high-flash gas from the high-pressure flash tank 1 enters the purification structure for purification to reduce the pollution and blockage of the stripping tower 6; the other part passes through the deaerator 7 to provide heat energy for the deaerator 7. The gas outlet of the low-pressure flash tank 2 is connected to the deaerator 7 through a low-flash gas outlet pipe 11, and the low-flash gas outlet pipe 11 is connected to the stripping tower 6 through a low-flash ventilation pipe 12. Part of the low-flash gas from the low-pressure flash tank 2 enters the deaerator 7 to provide heat energy for the deaerator 7, and the other part enters the stripping tower 6 for treatment.

[0023] The temperature of high flash gas from high-pressure flash tank 1 is about 176°C, and a part of the high flash gas is fixed to be directly sent to deaerator 7; the temperature of low flash gas from low-pressure flash tank 2 is about 138°C, and a part of it is sent to deaerator 7; the normal working temperature of deaerator 7 is maintained by adjusting the amount of low flash gas, so that the low-pressure steam of deaerator 7 can be kept off during normal operation, and high flash gas is used instead of low-pressure steam, which is beneficial to improve the utilization rate of heat and achieve the purpose of energy saving.

[0024] The high flash purification structure includes a saturated hot water tower 3, and the gas outlet of the high pressure flash tank 1 is connected to the saturated hot water tower 3 through a high flash outlet pipe 9. The high flash gas is purified by the saturated hot water tower 3. The gas outlet of the saturated hot water tower 3 is connected to the gas-water separator 5 through a cooling pipe 13, and a high flash cooler 4 is provided on the cooling pipe 13. The high flash cooler 4 cools the high flash gas, which is beneficial to reduce the water content in the high flash gas. The gas-water separator 5 is beneficial to reduce the water content in the high flash gas. The gas-water separator 5 is connected to the gas inlet of the stripping tower 6 or / and the torch through the gas outlet pipe. Most of the high flash gas coming out of the gas-water separator 5 is sent to the stripping tower 6 for treatment, and a small part is sent to the torch for combustion.

[0025] The liquid outlet of the gas-water separator 5 is connected to the deaerator 7, and the liquid outlet of the stripping tower 6 is connected to the deaerator 7, so as to replenish the deaerator 7. The deaerator 7 is connected to the liquid inlet of the saturated hot water tower 3 through a deaerator water pipe 15, and a deaerator pump 8 is provided on the deaerator water pipe 15, and the deaerator pump 8 sends deaerator water into the saturated hot water tower 3 to purify the high flash gas.

[0026] like Figure 2 As shown. The saturated hot water tower 3 is divided into a middle tower plate and an upper tower plate, and the upper tower plate is located above the middle tower plate. The deoxygenated water pipe 15 is connected to the liquid inlet of the middle tower plate, and the liquid inlet of the upper tower plate is connected to the desalted water. Since a part of the high flash gas is sent into the deaerator 7 through the high flash vent pipe 10, the amount of high flash gas entering the saturated hot water tower 3 is reduced, which is beneficial to reduce the load of the saturated hot water tower 3 and improve the purification effect of the high flash gas. The high flash gas is washed in two stages of deoxygenated water and cold desalted water in the saturated hot water tower 3, and the particulate impurities in the high flash gas are removed more cleanly, reducing the pollution and blockage of the stripping tower 6 by the high flash gas.

[0027] like Figure 3 As shown. The stripping tower 6 includes a packing layer 16, a condensing layer 17 and a spraying layer 18 which are arranged in sequence from bottom to top. The gas outlet of the low-flash vent pipe 12 on the stripping tower 6 and the gas outlet of the gas-water separator 5 are both located below the packing layer 16, and a steam inlet is provided below the packing layer 16. An acid condensate inlet is provided between the packing layer 16 and the condensing layer 17, and an ammonia water outlet is provided below the condensing layer 17. Cold desalted water is introduced into the condensing layer 17, and cold desalted water is introduced into the spraying layer 18. The gas outlet at the top of the stripping tower 6 is connected to a sulfur recovery device and / or a flare.

[0028] After passing through the packing layer 16 in the stripping tower 6, the high flash gas and the low flash gas are cooled and washed by the condensation layer 17 and the spray layer 18, which improves the treatment effect of the low flash gas and the high flash gas, reduces the problem of the high flash gas and the low flash gas, and reduces the impact of the high flash gas and the low flash gas on the subsequent sulfur recovery device. The high flash gas, the low flash gas and the steam are stripped for the pickling condensate, and the pickling condensate after stripping is discharged from the bottom of the stripping tower 6 into the deaerator 7 together with the condensed steam.

[0029] Steam is introduced into the deaerator 7. The high-pressure flash gas, low-pressure flash gas and steam entering the deaerator 7 further strip the pickling condensate entering the deaerator 7, thereby improving the treatment effect of the pickling condensate. The stripped gas is discharged from the top of the deaerator 7 and sent to the sulfur recovery device. A condenser is provided at the gas outlet of the deaerator 7, and the gas is cooled by the condenser.

[0030] The processing method based on the above-mentioned comprehensive processing device of flash steam comprises the following steps: S1, the gasified black water enters the high-pressure flash tank 1 for high-pressure flash evaporation, and the black water after high-pressure flash evaporation enters the low-pressure flash tank 2 through the bottom liquid outlet of the high-pressure flash tank 1 for further flash evaporation, and the black water after low-pressure flash evaporation is discharged to the true flash through the bottom liquid outlet.

[0031] S2. The gas portion in the high-pressure flash tank 1 enters the saturated hot water tower 3 through the top gas outlet, the deoxygenated water in the deaerator 7 enters the middle tower plate of the saturated hot water tower 3 through the deoxygenation pump 8, and the cold desalted water enters the upper tower plate of the saturated hot water tower 3. The high-flash gas is purified by the deoxygenated water and the desalted water; the gas portion in the high-pressure flash tank 1 enters the deaerator 7 through the high-flash ventilation pipe 10 to provide heat energy for the deaerator 7.

[0032] S3, the liquid in the saturated hot water tower 3 goes to the high-pressure ash water pump, the gas in the saturated hot water tower 3 enters the high flash cooler 4 through the cooling pipe 13 for cooling, and then is sent to the gas-water separator 5 for gas-water separation, the separated gas is sent to the stripping tower 6 and / or the flare, and the separated liquid is sent to the deaerator 7 for liquid replenishment.

[0033] S4. The gas in the low-pressure flash tank 2 partially enters the deaerator 7 through the low-flash outlet pipe 11 to provide heat energy for the deaerator 7; the low-flash gas in the low-flash outlet pipe 11 partially enters the stripping tower 6 through the low-flash ventilation pipe 12 for treatment.

[0034] S4. The high flash gas and low flash gas entering the stripping tower 6 are treated by the packing layer 16, and are cooled by the condensation layer 17 and the spray layer 18 and discharged from the top of the stripping tower 6 to the desulfurization recovery device or / flare; the acid condensate entering the stripping tower 6 is treated by the packing layer 16 and discharged into the deaerator 7 together with the condensed steam through the drain pipe 14 for liquid replenishment; the steam in the deaerator 7 further treats the acid condensate, and the treated gas is condensed by the condenser through the exhaust port and then discharged to the desulfurization recovery device.

[0035] Therefore, the use of the comprehensive flash steam treatment device and treatment method of the present invention can solve the problem that flash steam easily causes the stripping tower to be blocked, thereby affecting sulfur recovery.

[0036] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A comprehensive flash steam treatment device, characterized in that: It comprises a high-pressure flash tank and a low-pressure flash tank which are connected in sequence, the gas outlet of the high-pressure flash tank is provided with a high-flash gas outlet pipe, the high-flash gas outlet pipe is connected to the stripping tower through a high-flash purification structure, the high-flash gas outlet pipe is connected to the deaerator through a high-flash ventilation pipe, the gas outlet of the low-pressure flash tank is connected to the deaerator through a low-flash gas outlet pipe, the liquid outlet of the stripping tower is connected to the deaerator, and the deaerator is connected to the high-flash purification structure through a deoxygenation water pipe.

2. A comprehensive flash steam treatment device according to claim 1, characterized in that: The high flash purification structure comprises a saturated hot water tower, the gas outlet of the high pressure flash tank is connected to the saturated hot water tower through a high flash gas outlet pipe, the gas outlet of the saturated hot water tower is connected to a gas-water separator through a cooling pipe, the gas-water separator is connected to a gas inlet of a stripping tower or / and a flare through a gas outlet pipe, the liquid outlet of the gas-water separator is connected to a deaerator; a deoxygenation water pipe is connected to a liquid inlet of the saturated hot water tower, and a deoxygenation pump is arranged on the deoxygenation water pipe.

3. A comprehensive flash steam treatment device according to claim 1, characterized in that: A high flash cooler is arranged on the cooling pipe.

4. A comprehensive flash steam treatment device according to claim 1, characterized in that: The low flash exhaust pipe is connected with the stripping tower through a low flash ventilation pipe.

5. A comprehensive flash steam treatment device according to claim 2, characterized in that: The saturated hot water tower is segmented with a middle tower plate and an upper tower plate, the upper tower plate is located above the middle tower plate, the deoxygenated water pipe is connected to the liquid inlet of the middle tower plate, and the liquid inlet of the upper tower plate is connected to the desalted water.

6. A comprehensive flash steam treatment device according to claim 1, characterized in that: The stripping tower comprises a packing layer, a condensing layer and a spraying layer which are arranged in sequence from bottom to top; the gas outlet of the low-flash vent pipe on the stripping tower and the gas outlet of the gas-water separator are both located below the packing layer; a steam inlet is arranged below the packing layer; an acid condensate inlet is arranged between the packing layer and the condensing layer; an ammonia water outlet is arranged below the condensing layer; desalted water is introduced into the condensing layer; desalted water is introduced into the spraying layer; and the gas outlet at the top of the stripping tower is connected to a sulfur recovery device and / or a flare.

7. The comprehensive flash steam treatment device according to claim 1, characterized in that: The gas outlet of the deaerator is provided with a condenser, and the gas is sent to the sulfur recovery device through the condenser.

8. A flash steam comprehensive treatment device treatment method according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1, the gasified black water enters the high-pressure flash tank for high-pressure flash evaporation, and the black water after high-pressure flash evaporation enters the low-pressure flash tank through the bottom liquid outlet of the high-pressure flash tank for further flash evaporation, and the black water after low-pressure flash evaporation is discharged to the true flash through the bottom liquid outlet; S2. The gas in the high-pressure flash tank enters the saturated hot water tower through the top outlet, the deoxygenated water in the deaerator enters the middle tower plate of the saturated hot water tower through the deoxygenation pump, and the desalted water enters the upper tower plate of the saturated hot water tower. The high-flash gas is purified by the deoxygenated water and the desalted water; the gas in the high-pressure flash tank enters the deaerator through the high-flash vent pipe to provide heat energy for the deaerator; S3, the liquid in the saturated hot water tower goes to the high-pressure ash water pump, the gas in the saturated hot water tower enters the high flash cooler through the cooling pipe for cooling, and then is sent to the gas-water separator for gas-water separation, the separated gas is sent to the stripping tower and / or the flare, and the separated liquid is sent to the deaerator for liquid replenishment; S4. The gas in the low-pressure flash tank enters the deaerator through the low-flash outlet pipe to provide heat energy for the deaerator; the low-flash gas in the low-flash outlet pipe enters the stripping tower through the low-flash vent pipe for treatment; S4. The high flash gas and low flash gas entering the stripping tower are treated through the packing layer, and are cooled by the condensation layer and the spray layer, and then discharged from the top of the stripping tower to the desulfurization recovery device or / flare; the acid condensate entering the stripping tower is treated by the packing layer and then discharged into the deaerator together with the condensed steam through the drain pipe for liquid replenishment; the steam in the deaerator further treats the acid condensate, and the treated gas is condensed by the condenser through the exhaust port and then discharged to the desulfurization recovery device.

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