Cleaning device for horizontal pipe primary cooler

Abstract

The utility model belongs to the technical field of coking coal gas cooling, and particularly relates to a cleaning device of a horizontal pipe primary cooler, which comprises an upper section liquid inlet pipe, an upper section liquid return pipe, a lower section liquid inlet pipe, a lower section liquid return pipe, an upper section ammonia water pipe, a lower section ammonia water pipe and a steam pipe, the horizontal pipe primary cooler comprises an upper section and a lower section, the upper section is divided into a high-temperature section and a medium-temperature section, and the lower section is a low-temperature section. The bottom end of the low-temperature section is connected with a low-temperature water inlet pipe, the top end of the low-temperature section is connected with a low-temperature water outlet pipe, flushing pipelines are led out of the upper-section liquid returning pipe and the lower-section liquid returning pipe respectively and connected with small tar boats, one end of the upper-section ammonia water pipe is connected with an ammonia water tank through an ammonia water pump, and the other end of the upper-section ammonia water pipe is connected with an upper-section liquid inlet pipe. One end of the lower-section ammonia water pipe is connected with an ammonia water tank through an ammonia water pump, and the other end of the lower-section ammonia water pipe is connected with a lower-section liquid inlet pipe; according to the device, substances attached to the heat exchange pipe in the primary cooler are dissolved and washed through the steam pipe and the washing pipeline, and the resistance of the primary cooler is reduced.

Description

Technical Field

[0001] This utility model belongs to the field of coking gas cooling technology, and in particular relates to a cleaning device for a horizontal tube primary cooler. Background Technology

[0002] The horizontal tube primary cooler of the north-area blast cooling system of the 7.63m coke oven (No. 9 coke oven) at Taiyuan Iron & Steel Coking Plant was put into operation in 2013. Since December 2015, the resistance of the primary cooler has increased and remained high for an extended period, failing to meet the control target of <1500 Pa. After the primary cooler was shut down, inspection revealed a large accumulation of tar, coal dust, and other impurities on the outer wall of the heat exchange tubes in the lower section (low-temperature section). This reduced the gap between the heat exchange tubes, significantly shrinking the cross-sectional area of ​​the gas passage and causing the increased resistance, which severely impacted the stable operation of the gas system. To remove the impurities adhering to the outer wall of the heat exchange tube bundle and reduce the resistance, various methods were implemented, including gas overheating, hot ammonia flushing, steam purging, and the addition of chemicals. However, the resistance did not decrease significantly, reaching a maximum of over 4500 Pa (exceeding the instrument range), posing a significant safety risk to the normal operation of every process in the plant's chemical production area. Therefore, in 2019, the lower heat exchange tubes of three primary coolers were replaced. After the replacement, the resistance of the primary coolers returned to normal level in a short period of time.

[0003] In January 2021, the resistance of the primary cooler increased again, reaching a maximum of over 3000 Pa. On-site segmented measurement of the primary cooler resistance revealed that the increased resistance in primary coolers #2 and #3 was still concentrated in the lower section. After shutting down the primary coolers, inspection revealed a large amount of oil sludge on the outer wall of the lower section heat exchange tubes. The increased resistance in primary cooler #1 was mainly concentrated in the upper section (high-temperature and medium-temperature sections). Because the internal temperature of the high-temperature section is above 50℃, the amount of naphthalene and tar condensing is low, resulting in low resistance that has not changed significantly over a long period. Therefore, the resistance is mainly in the medium-temperature section. Existing methods for reducing primary cooler resistance cannot guarantee long-term stable operation of the primary cooler. There is an urgent need to improve the devices and methods for reducing primary cooler resistance. The following problems still exist in the actual implementation process:

[0004] (1) The pressure, temperature and flow rate of the flushing fluid cannot meet the requirements. When it comes into contact with the oil residue on the outer wall of the heat exchange tube of the primary cooler, the impact force cannot wash away the deposits.

[0005] (2) The flushing fluid has a poor dissolving effect on the oil residue on the outer wall of the heat exchange tube. Even after adding alkaline agents and emulsifiers, the flushing effect is still not obvious, and the primary cooler still cannot operate stably for a long period of time. Utility Model Content

[0006] The purpose of this invention is to provide a cleaning device for a horizontal tube primary cooler, which solves the problems in the prior art where the impact force of the flushing fluid is insufficient to wash away the deposits and the flushing fluid has a poor dissolving effect on the oil residue on the outer wall of the heat exchange tube.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A cleaning device for a horizontal tube primary cooler includes an upper inlet pipe, an upper outlet pipe, a lower inlet pipe, a lower outlet pipe, an upper ammonia water pipe, a lower ammonia water pipe, and a steam pipe. The horizontal tube primary cooler comprises an upper section and a lower section. The upper section is divided into a high-temperature section and a medium-temperature section, and the lower section is a low-temperature section. One end of the upper inlet pipe is connected to the upper condensate tank, and the other end is connected to the inlet at the top of the high-temperature section via an inlet pump. One end of the upper outlet pipe is connected to the outlet at the bottom of the medium-temperature section, and the other end is connected to the upper condensate tank. One end of the lower inlet pipe is connected to the lower condensate tank, and the other end is connected to the inlet at the top of the low-temperature section via an inlet pump. One end of the lower outlet pipe is connected to the lower condensate tank, and the other end is connected to the bottom of the low-temperature section. The upper and lower inlet pipes are equipped with valves at their respective inlet ports. Valves are also installed on the upper and lower outlet pipes. The bottom of the low-temperature section is connected to a low-temperature water inlet pipe, and the top of the low-temperature section is connected to a low-temperature water outlet pipe. Valves are installed on both the low-temperature water inlet and outlet pipes. Flushing pipes extend from both the upper and lower outlet pipes and are connected to a small tar tanker. Valves are installed on each flushing pipe. One end of the upper ammonia water pipe is connected to an ammonia tank via an ammonia water pump, and the other end is connected to the upper inlet pipe. One end of the lower ammonia water pipe is connected to an ammonia tank via an ammonia water pump, and the other end is connected to the lower inlet pipe. Valves are installed on both the upper and lower ammonia water pipes.

[0009] Preferably, a steam pipe is connected to the low-temperature water inlet pipe, and a valve is provided on the steam pipe.

[0010] Preferably, the small tar tanker is connected to an ammonia tank via a return pump.

[0011] Preferably, the lower section condensate tank is connected to the ammonia tank via a lower section drain pipe, and an external drain pump is connected to the lower section drain pipe. An upper section drain pipe is led out from the upper section inlet pipe above the inlet pump and connected to the ammonia tank. A regulating valve is installed on the upper section drain pipe.

[0012] Working Principle: The horizontal tube primary cooler is a standby unit. In operation, the gas is cooled by the cleaning fluid, circulating water, and low-temperature water, producing a large amount of condensate. The upper and lower sections of the condensate flow into the upper and lower condensate tanks, respectively, and are circulated and sprayed by the inlet pump to wash away naphthalene and tar residue adhering to the heat exchange tubes. At the same time, the inlet pump outlet on the upper inlet pipe is equipped with an automatic high-level discharge function. The regulating valve is interlocked with the liquid level of the upper inlet pipe. When the liquid level is high, the regulating valve opens automatically to discharge the condensate. The discharge pump on the discharge pipe of the lower condensate tank has an automatic start-stop function for high and low liquid levels to ensure effective discharge of impurities entrained in the primary cooler flushing fluid. This prevents naphthalene and tar residue from adhering to the outer wall of the heat exchange tubes during circulation, which would increase resistance and affect safe operation.

[0013] The specific cleaning steps for the standby horizontal tube primary cooler are as follows:

[0014] Close the gas inlet and outlet valves of the primary cooler, close the valves at the inlet of the upper and lower liquid inlet pipes, and close the valves on the upper and lower liquid return pipes. Open the valves on the flushing pipes, and then open the valves on the upper and lower ammonia water pipes to spray ammonia water for washing. Start the return pump to recover the washing liquid.

[0015] Close the valves on the low-temperature water inlet and outlet pipes, drain the water from the heat exchange tubes, open the valve on the steam pipe, heat the heat exchange tubes to melt the naphthalene, tar residue and other substances adhering to the outer wall of the heat exchange tubes, and begin a week-long hot ammonia water cleaning of the heat exchange tubes. The flushing cycle of the primary cooler can be set according to the resistance, generally one week is appropriate.

[0016] Special attention should be paid to the following during daily operation: control the cooling water temperature in the low-temperature section between 16-18℃ and maintain the cooling water temperature in the upper section of the primary cooler at around 32℃. This is to prevent a large amount of impurities such as naphthalene and tar in the gas from being precipitated and adsorbed on the outer wall of the heat exchange tube due to excessively low cooling water temperature, which would cause an increase in the resistance of the primary cooler.

[0017] The beneficial effects achieved by this utility model are as follows:

[0018] (1) During operation, the cleaning fluid in the upper and lower inlet pipes is used to initially clean the oil residue on the outer wall of the heat exchange tube. In combination with standby, the hot ammonia water in the upper and lower ammonia water pipes is used to further flush the oil residue on the outer wall of the heat exchange tube to ensure that the oil residue is washed away and to prevent insufficient impact force from washing away the deposits.

[0019] (2) In standby mode, water is discharged from the low-temperature section heat exchange tubes, and steam is used in the steam pipes to heat the low-temperature section heat exchange tubes. The heat of the steam is used to melt the oil residue on the outer wall of the heat exchange tubes, so that the tar, naphthalene and oil residue attached to the heat exchange tubes fall off and dissolve in the flushing liquid. The flushing liquid is then sent to the small tar boat for slag and liquid discharge, thus avoiding the problem of poor dissolution effect of the flushing liquid on the oil residue on the outer wall of the heat exchange tubes. Then, ammonia water is sprayed and flushed through the flushing pipe to ensure that it is clean. At the same time, the flushing pipe prevents the oil residue in the flushing liquid from entering the operating horizontal tube primary cooler. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure in an embodiment of the present utility model.

[0021] Explanation of reference numerals in the attached diagram: 1. Upper inlet pipe; 2. Upper outlet pipe; 3. Lower inlet pipe; 4. Lower outlet pipe; 5. Upper ammonia pipe; 6. Lower ammonia pipe; 7. Steam pipe; 8. Upper condensate tank; 9. First inlet pump; 10. Lower condensate tank; 11. Second inlet pump; 12. Low-temperature water inlet pipe; 13. Low-temperature water outlet pipe; 14. First flushing pipe; 15. Second flushing pipe; 16. Small tar boat; 17. Ammonia pump; 18. Ammonia tank; 19. Return pump; 20. Lower outlet pipe; 21. Lower outlet pump; 22. Upper outlet pipe; 23. Regulating valve. Detailed Implementation

[0022] The technical solution of this utility model will be clearly and completely described below with reference to the accompanying drawings and embodiments.

[0023] The horizontal tube primary cooler in this embodiment includes an upper section and a lower section. The upper section is divided into a high-temperature section and a medium-temperature section, and the lower section is a low-temperature section.

[0024] like Figure 1As shown, a cleaning device for a horizontal tube primary cooler includes an upper inlet pipe 1, an upper outlet pipe 2, a lower inlet pipe 3, a lower outlet pipe 4, an upper ammonia water pipe 5, a lower ammonia water pipe 6, and a steam pipe 7. One end of the upper inlet pipe 1 is connected to an upper condensate tank 8, and the other end is connected to the inlet at the top of the high-temperature section via a first inlet pump 9. One end of the upper outlet pipe 2 is connected to the outlet at the bottom of the medium-temperature section, and the other end is connected to the upper condensate tank 8. One end of the lower inlet pipe 3 is connected to a lower condensate tank 10, and the other end is connected to the inlet at the top of the low-temperature section via a second inlet pump 11. One end of the lower outlet pipe 4 is connected to the lower condensate tank 10, and the other end is connected to... At the bottom of the low-temperature section, valves are installed at the inlet of both the upper inlet pipe 1 and the lower inlet pipe 3. Valves are also installed on the upper outlet pipe 2 and the lower outlet pipe 4. The bottom of the low-temperature section is connected to the low-temperature water inlet pipe 12, and the top of the low-temperature section is connected to the low-temperature water outlet pipe 13. Valves are installed on both the low-temperature water inlet pipe 12 and the low-temperature water outlet pipe 13. The upper outlet pipe 2 and the lower outlet pipe 4 lead out to the first flushing pipe 14 and the second flushing pipe 15, respectively. Both the first flushing pipe 14 and the second flushing pipe 15 are connected to the small tar tanker 16. Valves are also installed on both the first flushing pipe 14 and the second flushing pipe 15. One end of the upper ammonia water pipe 5 is connected to the ammonia water pump 17. Ammonia tank 18 is connected to the ammonia inlet pipe 1 at one end, and the upper inlet pipe 1 at the other end is connected to the lower inlet pipe 3 at the other end. Valves are installed on both the upper ammonia inlet pipe 5 and the lower ammonia inlet pipe 6. A steam pipe 7 is connected to the low-temperature water inlet pipe 12, and a valve is installed on the steam pipe 7. The small tar tanker 16 is connected to the ammonia tank 18 through the return pump 19. The lower condensate tank 10 is connected to the ammonia tank 18 through the lower drain pipe 20, and the lower drain pump 21 is connected to the lower drain pipe 20. The upper drain pipe 22 is led out from the upper inlet pipe 1 above the first inlet pump 9 and connected to the ammonia tank 18. A regulating valve is installed on the upper drain pipe 22. 23; The cleaning fluid in the upper and lower inlet pipes is used to initially clean the oil residue on the outer wall of the heat exchange tubes. Combined with the hot ammonia water in the upper and lower ammonia water pipes, the oil residue on the outer wall of the heat exchange tubes is further rinsed to ensure that the oil residue is cleaned. The steam in the steam pipe is used to heat the low-temperature section heat exchange tubes. The heat of the steam melts the oil residue on the outer wall of the heat exchange tubes, causing the tar, naphthalene, and oil residue attached to the heat exchange tubes to fall off and dissolve in the flushing fluid. The flushing fluid is then discharged into the small tar ship through the first and second flushing pipes for slag and liquid discharge. During daily operation, the impurities carried in the primary cooler flushing fluid are discharged through the upper and lower external discharge pipes.

[0025] Using this device, combined with periodic flushing operations, the resistance of the primary cooler decreased from 3300Pa to 700Pa, a reduction of 79% (2600Pa), without any re-increase. The resistance of the primary cooler remained below 1500Pa for an extended period, reducing the frequency of shutdowns for maintenance or heat exchanger tube replacement due to high resistance, resulting in a total reduction in maintenance costs of approximately 2 million yuan. The use of chemicals and emulsifiers was also reduced, with emulsifier consumption decreasing from 1400kg per month to 1000kg, effectively saving 150,000 yuan annually.

Claims

1. A cleaning device for a horizontal tube primary cooler, comprising an upper inlet pipe, an upper outlet pipe, a lower inlet pipe, a lower outlet pipe, an upper ammonia water pipe, a lower ammonia water pipe, and a steam pipe. The horizontal tube primary cooler includes an upper section and a lower section. The upper section is divided into a high-temperature section and a medium-temperature section, and the lower section is a low-temperature section. One end of the upper inlet pipe is connected to an upper condensate tank, and the other end is connected to the inlet at the top of the high-temperature section via an inlet pump. One end of the upper outlet pipe is connected to the outlet at the bottom of the medium-temperature section, and the other end is connected to the upper condensate tank. One end of the lower inlet pipe is connected to the lower condensate tank, and the other end is connected to the inlet at the top of the low-temperature section via an inlet pump. One end of the lower outlet pipe is connected to the lower condensate tank, and the other end is connected to the outlet at the bottom of the low-temperature section. Valves are provided at the inlets of both the upper and lower inlet pipes, and valves are provided on both the upper and lower outlet pipes. The low-temperature section is connected to a low-temperature water inlet pipe at its bottom and a low-temperature water outlet pipe at its top. Valves are installed on both the low-temperature water inlet and outlet pipes. Flushing pipes are led out from the upper and lower effluent pipes and connected to a small tar tanker. Valves are installed on both flushing pipes. One end of the upper ammonia water pipe is connected to an ammonia water tank via an ammonia water pump, and the other end is connected to the upper inlet pipe. One end of the lower ammonia water pipe is connected to an ammonia water tank via an ammonia water pump, and the other end is connected to the lower inlet pipe. Valves are installed on both the upper and lower ammonia water pipes.

2. The cleaning device for a horizontal tube primary cooler according to claim 1, characterized in that, A steam pipe is connected to the low-temperature water inlet pipe, and a valve is installed on the steam pipe.

3. A cleaning device for a horizontal tube primary cooler according to any one of claims 1 or 2, characterized in that, The small tar tanker is connected to an ammonia tank via a return pump.

4. The cleaning device for a horizontal tube primary cooler according to claim 3, characterized in that, The lower section condensate tank is connected to the ammonia tank via a lower section drain pipe. An external drain pump is connected to the lower section drain pipe. An upper section drain pipe is led out from above the inlet pump and connected to the ammonia tank. A regulating valve is installed on the upper section drain pipe.

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