Combined device for deaerating steam and recovering condensate

Abstract

The utility model relates to the technical field of synthetic ammonia from coal, and concretely provides a combined device for recovering deoxygenated steam and condensate, which comprises a deaerator and a stripping tower, the upper part of the deaerator is provided with a deoxygenation water inlet pipe, and the lower part is provided with a deoxygenation steam inlet pipe, one side of the stripping tower is connected to the deaerator through a pipeline and is used for recovering the deoxygenated steam in the deaerator, the other side is connected to an ammonia washing tower through a condensate pipe and is used for recovering the ammonia-containing condensate water in the ammonia washing tower, the other side is connected to a condensate pump through a condensate pump inlet pipe and then supplies the gasification section for recycling, and the lower part of the stripping tower is provided with a blowdown pipe; the outlet end of the deaerator is connected to a deoxygenated water pump through a deoxygenated water pump inlet pipe, and the deoxygenated water pump is delivered to each water point in the production system after being boosted. Compared with the prior art, the utility model recovers and utilizes the heat in the deoxygenated steam, effectively avoids heat waste, reduces the consumption of steam in the stripping tower, and condenses and recovers the water vapor entrained in the deoxygenated steam for recycling, thereby achieving remarkable energy-saving and consumption-reducing effects.

Description

Technical Field

[0001] This utility model relates to the field of coal-to-ammonia synthesis technology, specifically providing a combined device for deoxygenated exhaust steam and condensate recovery. Background Technology

[0002] In the new coal gasification ammonia synthesis process, demineralized water is used throughout the entire process, serving as washing water, cooling water, and makeup water for the circulating system; it is the "blood" of the entire production process. However, dissolved oxygen in the water can cause corrosion of metals in contact with the water. To ensure water quality and prevent oxygen corrosion of equipment and pipelines, the feedwater system of the ammonia synthesis process is generally equipped with a deaerator. In the deaerator, steam is used to heat the water, increasing its temperature and gradually increasing the partial pressure of steam above the water surface, while the partial pressure of dissolved gases gradually decreases. Dissolved gases continuously escape. When the water is heated to its boiling point at the corresponding pressure, the surface is entirely covered with steam. The partial pressure of dissolved gases becomes zero, and the water no longer has the ability to dissolve gases; that is, dissolved oxygen and other non-condensable gases can be removed. The oxygen and other non-condensable gases released during deaeration mix to form exhaust steam, which is generally vented directly, resulting in a significant waste of heat in the exhaust steam.

[0003] Meanwhile, in the ammonia conversion section, the produced conversion gas contains a small amount of ammonia. To avoid the ammonia in the conversion gas affecting the low-temperature methanol washing, a conversion gas ammonia washing tower is usually designed to remove the small amount of ammonia from the conversion gas. At this time, the conversion condensate at the bottom of the ammonia washing tower has a high ammonia content. To further recover and utilize the condensate, a stripping process is generally used for the condensate. That is, the condensate enters the stripping tower and is stripped using 0.5MPa saturated steam. The ammonia-containing non-condensable gas from the top of the tower is sent to sulfur recovery treatment, and the low-temperature condensate at the bottom of the tower is sent to gasification for recycling. However, this condensate purification process consumes a large amount of 0.5MPa saturated steam, resulting in high production costs.

[0004] In summary, how to recover and utilize the heat from the deaerated exhaust steam, effectively avoid heat waste, reduce the consumption of steam in the stripping tower, and simultaneously condense and recover the water vapor entrained in the exhaust steam is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] This utility model addresses the shortcomings of the prior art by providing a combined device for deoxygenated exhaust gas and condensate recovery that is rationally designed, simple in structure, safe to use, and energy-saving.

[0006] The technical solution adopted by this utility model to solve its technical problem is:

[0007] A combined device for deoxygenated exhaust steam and condensate recovery includes a deaerator and a stripping tower. The deaerator is provided with a deoxygenated water inlet pipe at the top and a deoxygenated steam inlet pipe at the bottom. One side of the stripping tower is connected to the deaerator via a pipeline for recovering the exhaust steam in the deaerator. The other side is connected to an ammonia washing tower via a condensate pipe for recovering ammonia-containing condensate in the ammonia washing tower. The other side is connected to a condensate pump via a condensate pump inlet pipe for recycling in the gasification section. A drain pipe is provided at the bottom of the stripping tower.

[0008] The deaerator outlet is connected to a deaerator water pump via a deaerator water pump inlet pipe. After being pressurized, the deaerator water pump delivers the water to various water-using points in the production system.

[0009] Furthermore, the stripping tower is also connected to a stripping steam inlet pipe, and the top of the deaerator is equipped with a waste steam exhaust pipe. The waste steam exhaust pipe is equipped with a vent valve, and a waste steam branch pipe is set in front of the vent valve. During normal production, the vent valve is closed, and the waste steam generated by the deaerator is connected to the stripping steam inlet pipe through the waste steam branch pipe and transported to the stripping tower for use as a stripping heat source.

[0010] Furthermore, a check valve IV is installed on the exhaust steam branch pipe, and a check valve I is installed on the stripping steam inlet pipe, with the connection point of the exhaust steam branch pipe located after check valve I.

[0011] Furthermore, an automatic regulating valve I and a pressure gauge I are also installed on the exhaust steam branch pipe, and the automatic regulating valve I and the pressure gauge I form an automatic regulating circuit;

[0012] The stripping steam inlet pipe is equipped with an automatic regulating valve II and a pressure gauge II, which together form an automatic regulating circuit.

[0013] Furthermore, the ammonia washing tower is equipped with an ammonia washing tower outlet pipe at the top, a demineralized water inlet pipe at the upper inlet end, an ammonia washing tower air inlet pipe at the middle inlet end, and a condensate pipe at the bottom outlet end connected to the stripping tower.

[0014] Furthermore, the condensate pipe is equipped with a level gauge II and an automatic regulating valve III, and the level gauge II 30 and the automatic regulating valve III 32 are configured as an automatic regulating circuit.

[0015] Furthermore, the outlet end of the condensate pump is connected to a condensate pump outlet pipe, and a check valve III is provided on the condensate pump outlet pipe.

[0016] Furthermore, the outlet end of the deoxygenated water pump is connected to a deoxygenated water pump outlet pipe, and a check valve II is provided on the deoxygenated water pump outlet pipe.

[0017] Furthermore, a flow meter is installed on the demineralized water inlet pipe, and a level gauge I is installed on the stripping tower.

[0018] Compared with existing technologies, the combined device for deoxygenated waste steam and condensate recovery of this utility model has the following outstanding advantages:

[0019] This invention reduces the amount of 0.5MPa saturated steam used in the stripping tower by recovering exhaust steam from the deaerator, resulting in significant energy savings and reduced consumption. Condensate from the ammonia washing tower is recovered through the condensate pipe, and condensable gases in the exhaust steam in the stripping tower are condensed into condensate for recycling, leading to significant water savings.

[0020] Because a portion of the exhaust steam is recovered by the stripping tower, the amount of exhaust steam vented is reduced, thus avoiding environmental pollution and achieving significant environmental benefits. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Appendix Figure 1 This is a schematic diagram of a combined device for deoxygenated exhaust gas and condensate recovery.

[0023] The markings in the attached diagram represent:

[0024] 1. Deaerator; 2. Stripping tower; 3. Ammonia scrubbing tower; 4. Deaerator water pump; 5. Condensate pump; 6. Deaerator inlet pipe; 7. Deaerator steam inlet pipe; 8. Deaerator water pump inlet pipe; 9. Deaerator water pump outlet pipe; 10. Exhaust steam exhaust pipe; 11. Exhaust steam branch pipe; 12. Stripping steam inlet pipe; 13. Non-condensable gas pipe; 14. Condensate pump inlet pipe; 15. Condensate pump outlet pipe; 16. Sewage pipe; 17. Ammonia scrubbing pipe. 18. Demineralized water inlet pipe, 19. Ammonia washing tower outlet pipe, 20. Condensate pipe, 21. Automatic regulating valve I, 22. Automatic regulating valve II, 23. Check valve I, 24. Check valve II, 25. Check valve III, 26. Vent valve, 27. Pressure gauge I, 28. Pressure gauge II, 29. Level gauge I, 30. Level gauge II, 31. Check valve IV, 32. Automatic regulating valve III, 33. Flow meter. Detailed Implementation

[0025] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but this is not intended to limit the present invention.

[0026] In this utility model, unless otherwise stated, directional terms such as "upper," "lower," "left," and "right" generally refer to the upper, lower, left, and right as shown in the accompanying drawings; "inner" and "outer" refer to the inner and outer contours of each component itself.

[0027] The following is a preferred embodiment:

[0028] This embodiment of a combined device for deoxygenated exhaust steam and condensate recovery includes a deaerator 1 and a stripping tower 2. The upper part of the deaerator 1 is provided with a deoxygenated water inlet pipe 6 and the lower part is provided with a deoxygenated steam inlet pipe 7. In this embodiment, the left side of the stripping tower 2 is connected to the deaerator 1 through a pipeline for recovering the exhaust steam in the deaerator 1.

[0029] One path on the right is connected to the ammonia washing tower 3 via the condensate pipe 20, used to recover the ammonia-containing condensate in the ammonia washing tower 3. The other path is connected to the condensate pump 5 via the condensate pump inlet pipe 14, which then supplies the gas chemical section for recycling. A drain pipe 16 is provided at the bottom of the stripping tower 2.

[0030] The outlet end of deaerator 1 is connected to deaerator water pump 4 through deaerator water pump inlet pipe 8. After depressurization, deaerator water pump 4 delivers water to each water point in the production system.

[0031] The stripping tower 2 is also connected to a stripping steam inlet pipe 12. The top of the deaerator 1 is equipped with a waste steam exhaust pipe 10, and a vent valve 26 is installed on the waste steam exhaust pipe 10. A waste steam branch pipe 11 is installed in front of the vent valve 26. During normal production, the vent valve 26 is closed, and the waste steam generated by the deaerator 1 is connected to the stripping steam inlet pipe 12 through the waste steam branch pipe 11 and transported to the stripping tower 2 as a stripping heat source.

[0032] A check valve IV31 is installed on the exhaust steam branch pipe 11, and a check valve I23 is installed on the stripping steam inlet pipe 12. The connection point of the exhaust steam branch pipe 11 is after the check valve I23.

[0033] Automatic regulating valve I21 and pressure gauge I27 are also installed on the exhaust steam branch pipe 11. Automatic regulating valve I21 and pressure gauge I27 form the first set of automatic regulating circuits.

[0034] An automatic regulating valve II22 and a pressure gauge II28 are installed on the stripping steam inlet pipe 12. The automatic regulating valve II22 and the pressure gauge II28 form the second set of automatic regulating circuits.

[0035] The ammonia washing tower 3 is equipped with an ammonia washing tower outlet pipe 19 at the top, a demineralized water inlet pipe 18 at the upper inlet end, an ammonia washing tower air inlet pipe 17 at the middle inlet end, and a condensate pipe 20 at the bottom outlet end connected to the stripping tower 2.

[0036] The condensate pipe 20 is equipped with a level gauge II 30 and an automatic regulating valve III 32. The level gauge II 30 and the automatic regulating valve III 32 are configured as the third automatic regulating circuit.

[0037] The outlet end of the condensate pump 5 is connected to the condensate pump outlet pipe 15, and the condensate pump outlet pipe 15 is equipped with a check valve Ⅲ25.

[0038] The outlet end of the deoxygenated water pump 4 is connected to the deoxygenated water pump outlet pipe 9, and a check valve II 24 is installed on the deoxygenated water pump outlet pipe 9. In this embodiment, a flow meter 33 is installed on the demineralized water inlet pipe 18, and a level gauge I 29 is installed on the stripping tower 2.

[0039] In this embodiment, a combined device for deaeration of exhaust steam and recovery of condensate is used. The feed water of deaerator 1 enters the upper part of the deaeration head of deaerator 1 through the deaerator inlet pipe 6 and flows from top to bottom through the packing layer in the deaeration head. The steam enters the lower part of the deaeration head of deaerator 1 through the deaeration steam inlet pipe 7 and flows from bottom to top through the packing layer in the deaeration head. It contacts the feed water of deaerator 1 in a countercurrent flow to heat the feed water and increase the water temperature. This causes the partial pressure of steam on the water surface to gradually increase, while the partial pressure of dissolved gas gradually decreases. The gas dissolved in the water continuously escapes. When the water is heated to the boiling temperature at the corresponding pressure, the water surface is covered with water vapor.

[0040] The partial pressure of dissolved gases is zero, and water no longer has the ability to dissolve gases; that is, all dissolved oxygen and other non-condensable gases in the water are removed. The oxygen and other non-condensable gases released during deoxygenation mix to form exhaust steam, which is discharged through exhaust steam pipe 10. The water with dissolved oxygen removed becomes deoxygenated water and enters deoxygenated water pump 4 through inlet pipe 8 to increase pressure.

[0041] Ammonia-containing condensate from the ammonia scrubbing tower 3 enters the stripping tower 2 through the condensate pipe 20. Waste steam or vapor enters the stripping tower 2 through the stripping steam inlet pipe 12. Inside the stripping tower 2, the ammonia in the condensate is released through a gas-based process, transforming it into high-quality condensate. This condensate is then pumped to the condensate pump 5 for pressurization via the condensate pump inlet pipe 14, and finally transported to the gasification section for recycling via the condensate pump outlet pipe 15. Ammonia-containing non-condensable gas is discharged from the stripping tower 2 through the non-condensable gas pipe 13 and transported to the sulfur recovery section for processing.

[0042] The shift gas containing a small amount of ammonia produced in the gasification section enters the lower part of the ammonia scrubbing tower 3 through the ammonia scrubbing tower inlet pipe 17, while the demineralized water enters the upper part of the ammonia scrubbing tower 3 through the demineralized water inlet pipe 18. Inside the ammonia scrubbing tower 3, the shift gas flows from bottom to top, and the demineralized water is sprayed from top to bottom. Through countercurrent contact, the ammonia in the shift gas is absorbed by the demineralized water, and the clean shift gas is transported to the next stage through the ammonia scrubbing tower outlet pipe 19. After absorbing the ammonia in the shift gas, the demineralized water becomes condensate and is transported to the stripping tower 2 through the condensate pipe 20 for stripping.

[0043] The deoxygenated water, after removing dissolved oxygen, is stored in the storage area of ​​deaerator 1, and then enters deaerator pump 4 through deaerator pump inlet pipe 8 for pressurization, and is then transported to various water points in the production system through deaerator pump outlet pipe 9.

[0044] Condensate enters condensate pump 5 through condensate pump inlet pipe 14 for pressurization, and then is transported to the gasification section for recycling through condensate pump outlet pipe 15.

[0045] When the vent valve 26 is closed, the exhaust steam generated by deoxygenation is connected to the stripping steam inlet pipe 12 through the exhaust steam branch pipe 11 and transported to the stripping tower 2 as a stripping heat source. If the stripping tower 2 no longer needs exhaust steam, the vent valve 26 is opened and the exhaust steam is vented through the exhaust steam exhaust pipe 10 without affecting normal production.

[0046] The drain pipe 16 at the bottom of the stripping tower 2 can discharge condensate into the ditch through the drain pipe 16 when the equipment fails and the condensate cannot be sent out or the condensate quality is unqualified.

[0047] The check valve III25 installed on the outlet pipe 15 of the condensate pump and the check valve II24 installed on the outlet pipe 9 of the deaerator pump can prevent backflow of water caused by water pressure fluctuations, thus avoiding equipment damage and production accidents.

[0048] Check valve IV31 is installed on the exhaust steam branch pipe 11, and check valve I23 is installed on the stripping steam inlet pipe 12. By installing check valves, cross-flow of gas between the two gas lines entering the stripping tower due to pressure fluctuations is prevented, thus ensuring the stable operation of the system.

[0049] The first and second automatic adjustment loops are used to ensure the stability and balance of the gas pressure in the two gas lines of the stripping tower.

[0050] The third automatic adjustment loop regulating valve Ⅲ32 can automatically adjust its opening degree according to the value of the level gauge Ⅱ30 to ensure that the liquid level of the ammonia washing tower 3 is in a stable state.

[0051] The level gauge I29 installed on stripping tower 2 can transmit data to the DCS system to monitor the level of the stripping tower and ensure stable production.

[0052] The flow meter 33 installed on the desalination water inlet pipe 18 can be used to monitor the water inlet flow of the desalination water inlet pipe 18.

[0053] The embodiments described above are merely one preferred embodiment of this utility model. Ordinary variations and substitutions made by those skilled in the art within the scope of this utility model's technical solution should be included within the protection scope of this utility model.

Claims

1. A combined device for deoxygenated waste steam and condensate recovery, comprising a deaerator and a stripping tower, wherein the deaerator is provided with a deoxygenated water inlet pipe at the upper part and a deoxygenated steam inlet pipe at the lower part, characterized in that, One side of the stripping tower is connected to the deaerator via a pipeline for recovering the exhaust steam in the deaerator. The other side is connected to the ammonia washing tower via a condensate pipe for recovering the ammonia-containing condensate in the ammonia washing tower. The other side is connected to the condensate pump via the condensate pump inlet pipe and then supplied to the gas chemical section for recycling. A drain pipe is provided at the bottom of the stripping tower. The deaerator outlet is connected to a deaerator water pump via a deaerator water pump inlet pipe. After being pressurized, the deaerator water pump delivers the water to various water-using points in the production system.

2. The combined device for deoxygenated waste steam and condensate recovery according to claim 1, characterized in that, The stripping tower is also connected to a stripping steam inlet pipe. The top of the deaerator is equipped with a waste steam exhaust pipe, and a vent valve is installed on the waste steam exhaust pipe. A waste steam branch pipe is installed before the vent valve. During normal production, the vent valve is closed, and the waste steam generated by the deaerator is connected to the stripping steam inlet pipe through the waste steam branch pipe and transported to the stripping tower for use as a stripping heat source.

3. The combined device for deoxygenated waste steam and condensate recovery according to claim 2, characterized in that, A check valve IV is installed on the exhaust steam branch pipe, and a check valve I is installed on the stripping steam inlet pipe. The connection point of the exhaust steam branch pipe is after the check valve I.

4. The combined device for deoxygenated waste gas and condensate recovery according to claim 3, characterized in that, The exhaust steam branch pipe is also equipped with an automatic regulating valve I and a pressure gauge I, which together form an automatic regulating circuit. The stripping steam inlet pipe is equipped with an automatic regulating valve II and a pressure gauge II, which together form an automatic regulating circuit.

5. The combined apparatus for deoxygenated waste gas and condensate recovery according to claim 4, characterized in that, The ammonia washing tower is equipped with an ammonia washing tower outlet pipe at the top, a demineralized water inlet pipe at the upper inlet end, an ammonia washing tower air inlet pipe at the middle inlet end, and a condensate pipe at the bottom outlet end connected to the stripping tower.

6. The combined apparatus for deoxygenated waste gas and condensate recovery according to claim 5, characterized in that, The condensate pipe is equipped with a level gauge II and an automatic regulating valve III, and the level gauge II and the automatic regulating valve III are configured as an automatic regulating loop.

7. The combined apparatus for deoxygenated waste steam and condensate recovery according to claim 6, characterized in that, The outlet end of the condensate pump is connected to a condensate pump outlet pipe, and a check valve III is installed on the condensate pump outlet pipe.

8. The combined apparatus for deoxygenated waste steam and condensate recovery according to claim 7, characterized in that, The outlet end of the deoxygenated water pump is connected to a deoxygenated water pump outlet pipe, and a check valve II is installed on the deoxygenated water pump outlet pipe.

9. The combined apparatus for deoxygenated waste steam and condensate recovery according to claim 8, characterized in that, A flow meter is installed on the demineralized water inlet pipe, and a level gauge I is installed on the stripping tower.

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