Gas cooling device and gas cooling method

Abstract

To provide a gas cooling device where the installation space for a heat exchanger can be reduced and the introduction cost and power cost of a pump can be reduced.SOLUTION: A gas cooling device 100 for cooling a gas by counter flow contact of a gas with a liquid is assembled with a cooling tower 50 having a liquid retention part 52 at its bottom, a first channel 10 for leading a liquid 45 from the liquid retention part 52 and introducing the liquid from a first introduction port 11 provided on an upper part of the cooling tower 50 than the liquid retention part 52, a heat exchanger 20 provided in the liquid retention part 52 for cooling the liquid 45, and a second channel 22 for supplying a coolant to the heat exchanger 20.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] One aspect of the present disclosure relates to a gas cooling device and a method for cooling a gas.

Background Art

[0002] Cooling towers are used to cool coke oven gas and various other gases. In a cooling tower, also known as a direct cooler, coke oven gas is introduced from the lower part of the cooling tower, and cooling water is sprayed from the upper part of the cooling tower to bring the gas and the cooling water into direct contact. For example, Patent Document 1 discloses a cooling device including a cooling tower that brings coke oven gas generated in a coke oven and treated in a dry domain into contact with circulating cooling water. The cooling water collected in the water collection part at the bottom of this cooling tower is led out of the cooling tower and then introduced by a pump into a cooler provided outside the cooling tower for heat exchange and cooling. The thus-cooled cooling water is circulated and used in the cooling tower.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When providing a heat exchanger such as a cooler outside the cooling tower, it is necessary to secure an installation space therefor. Further, when cooling water flows through the inside of such a heat exchanger, a pressure loss occurs, so it is necessary to increase the discharge pressure of the pump. The present disclosure provides a gas cooling device and a method for cooling a gas that can reduce the installation space of the heat exchanger and reduce the introduction cost and power cost of the pump.

Means for Solving the Problems

[0005] This disclosure provides a gas cooling device for cooling a gas by bringing a gas and a liquid into countercurrent contact, comprising: a cooling tower having a liquid reservoir at its bottom; a first flow path for leading the liquid from the liquid reservoir and introducing the liquid from a first inlet provided above the liquid reservoir in the cooling tower; a heat exchanger provided in the liquid reservoir for cooling the liquid; and a second flow path for supplying a refrigerant to the heat exchanger.

[0006] The above-described gas cooling system includes a heat exchanger in the liquid reservoir at the bottom of the cooling tower. Therefore, the installation space required for the heat exchanger can be reduced compared to when the heat exchanger is installed outside the cooling tower. Furthermore, the heat exchanger supplied with refrigerant through the second flow path is located in the liquid reservoir. As a result, the liquid in countercurrent contact with the gas can be cooled without the need for a heat exchanger in the first flow path. Consequently, the system can operate effectively even with a reduced pump capacity required to circulate the liquid through the first flow path, thereby reducing pump installation costs and power costs.

[0007] The cooling tower of the above-mentioned gas cooling system may have an overflow weir in the liquid reservoir, and the heat exchanger may be immersed in the liquid retained by the overflow weir. This allows sufficient contact between the heat exchanger and the liquid in the liquid reservoir. Therefore, the liquid can be efficiently cooled by heat exchange with the heat exchanger.

[0008] Any of the above gas cooling devices includes a third flow path that leads the liquid recovered in a chimney tray, which is provided between the liquid reservoir and the first inlet, out of the cooling tower and into the liquid reservoir. The third flow path may introduce the liquid into the liquid reservoir from a second inlet located below the heat exchanger. This reduces the amount of liquid that overflows the chimney tray and is led out of the liquid reservoir without sufficient contact with the heat exchanger. Therefore, it becomes possible to ensure sufficient contact between the liquid, which has become hotter after contact with the gas, and the heat exchanger, thereby efficiently cooling the liquid.

[0009] In any of the above gas cooling devices, the third flow path may introduce the liquid recovered in the chimney tray into the liquid reservoir from the second inlet using only head pressure. This eliminates the need to install pumps, etc., and further reduces equipment costs and power costs.

[0010] In any of the above gas cooling devices, the third flow path may have a flow control valve, and the liquid level in the chimney tray may be controlled to a predetermined range by adjusting the flow rate of the liquid flowing through the third flow path with the flow control valve. This suppresses overflow of the chimney tray and allows a sufficiently large amount of liquid to come into contact with the heat exchanger. Therefore, the liquid can be efficiently cooled by the heat exchanger.

[0011] In any of the above gas cooling devices, the first flow path may have a pump, and the third flow path may have a flow control valve. The flow rate of the liquid flowing through the third flow path may be adjusted by the flow control valve to control the liquid level in the liquid reservoir within a predetermined range. This makes it possible to maintain the liquid level in the liquid reservoir even when the device is started up or during operational fluctuations, and to sufficiently suppress cavitation and idling of the pump in the first flow path.

[0012] In any of the above gas cooling systems, the gas introduced into the cooling tower may include coke oven gas. Coke oven gas cooling systems are typically large, with a processing capacity of, for example, 100,000 Nm³. 3 The rate is approximately / h. Because the cooling system is large, the effect of reducing installation space, as well as the effect of reducing the cost of introducing the pump and the power supply costs, can be further enhanced.

[0013] In any of the above gas cooling devices, at least a portion of the liquid reservoir may extend horizontally beyond the portion of the cooling tower other than the liquid reservoir. This allows for a larger heat exchanger and facilitates the installation and maintenance of the heat exchanger.

[0014] This disclosure provides a method for cooling a gas by bringing a gas and a liquid into countercurrent contact using a cooling tower, comprising the steps of: cooling the liquid with a heat exchanger provided in a liquid reservoir at the bottom of the cooling tower and supplied with a refrigerant from outside the cooling tower; and circulating the liquid by discharging the liquid cooled by the heat exchanger from the liquid reservoir and introducing the liquid from a first inlet provided in the upper part of the cooling tower above the liquid reservoir.

[0015] The above-described gas cooling method uses a heat exchanger installed in the liquid reservoir at the bottom of the cooling tower to cool the liquid in contact with the gas. Therefore, the installation space for the heat exchanger can be reduced compared to when the heat exchanger is installed outside the cooling tower. Furthermore, the liquid in countercurrent contact with the gas can be cooled even without installing a heat exchanger in the first flow path. Consequently, it is possible to operate the system sufficiently even with a reduced pump capacity required for the liquid to flow through the first flow path, thereby reducing the pump introduction cost and power costs.

[0016] The above gas cooling method may include a step of discharging the liquid recovered in a chimney tray provided between the liquid reservoir of the cooling tower and the first inlet from the cooling tower and introducing it into the liquid reservoir of the cooling tower. This reduces the amount of liquid discharged from the liquid reservoir without sufficient contact with the heat exchanger. Therefore, it becomes possible to bring the liquid, whose temperature has risen due to contact with the gas, into sufficient contact with the heat exchanger, and the liquid can be efficiently cooled by heat exchange with the refrigerant. [Effects of the Invention]

[0017] This invention provides a gas cooling system and a gas cooling method that reduce the installation space required for the heat exchanger, as well as the introduction and power costs of the pump. [Brief explanation of the drawing]

[0018] [Figure 1] This figure schematically shows a gas cooling device according to the first embodiment. [Figure 2]It is a diagram schematically showing the gas cooling device of the second embodiment. [Figure 3] It is a diagram schematically showing the gas cooling device of the third embodiment. [Figure 4] It is a diagram schematically showing the gas cooling device of the fourth embodiment.

Modes for Carrying Out the Invention

[0019] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings as appropriate. However, the following embodiments are examples for explaining the present disclosure, and are not intended to limit the present disclosure to the following contents. In the description, the same reference numerals are used for the same elements or elements having the same function, and redundant descriptions may be omitted as appropriate. Also, the positional relationships such as up, down, left, and right are based on the directions of the reference numerals in the drawings unless otherwise specified. Furthermore, the dimensional ratios in the drawings are not limited to the illustrated ratios.

[0020] The gas cooling device 100 of the first embodiment shown in FIG. 1 cools COG (coke oven gas) by countercurrent contact with a liquid 45 in a cooling tower 50. The liquid 45 may be water such as industrial water, or may be ammonia water containing ammonia derived from COG. The cooling tower 50 has a liquid reservoir portion 52 where the liquid stays at the lower part. The liquid reservoir portion 52 refers to a portion where the liquid 45 that has contacted COG temporarily accumulates, and a portion that is filled with the liquid 45 during operation.

[0021] The cooling tower 50 is provided with a first outlet 15 for leading out the liquid 45 staying in the liquid reservoir portion 52 to the outside of the cooling tower 50. The liquid 45 led out from the first outlet 15 flows through the first flow path 10 and is introduced into the cooling tower 50 from a first inlet 11 provided at the upper part of the cooling tower 50. Thus, the cooling tower 50 and the first flow path 10 constitute a circulation path of the liquid 45. The first inlet 11 may be merely a through hole, or may have a tubular or annular nozzle that discharges the liquid in a shower shape at the tip.

[0022] The heat exchanger 20 is built into the liquid reservoir portion 52 of the cooling tower 50. The heat exchanger 20 is immersed in the liquid 45 that stays in the liquid reservoir portion 52. A second flow path 22 for supplying refrigerant from outside the cooling tower 50 is connected to the heat exchanger 20. The second flow path 22 penetrates the lower part of the cooling tower 50 from outside the cooling tower 50 and is connected to the heat exchanger 20, introducing the refrigerant into the heat exchanger 20 and导出 the refrigerant that has flowed through the heat exchanger 20 and exchanged heat with the liquid 45 to the outside of the cooling tower 50. The refrigerant may be, for example, cooling water such as industrial water and seawater. Also, the heat exchanger 20 and the second flow path 22 may form a circulation path of the refrigerant together with a cooler (not shown) that cools the refrigerant. Thereby, the refrigerant can be used while being circulated.

[0023] As the heat exchanger 20, various structures such as a plate heat exchanger, a multi-tube heat exchanger, and a tube-type heat exchanger can be used. Among these, from the viewpoint of being easy to miniaturize and efficiently cooling the liquid 45, a plate heat exchanger may be used. The number of heat exchangers 20 is not limited, and it may be one or two or more.

[0024] Between the first inlet 11 and the liquid reservoir portion 52, a packing layer 56 and a chimney tray 35 are provided in this order from above to below. The packing layer 56 is provided to increase the contact efficiency between the COG and the liquid, and for example, may be filled with packings such as Raschig rings. The first inlet 11 is provided above the packing layer 56, and the chimney tray 35 is provided below the packing layer 56. Thereby, the liquid 45 introduced from the first inlet 11 passes through the packing layer 56 and is then collected by the chimney tray 35.

[0025] A third inlet 51 for introducing COG into the cooling tower 50 is provided between the packed bed 56 and the chimney tray 35. The COG introduced from the third inlet 51 rises within the cooling tower 50 and passes through the packed bed 56. At this time, it is cooled by countercurrent contact with the liquid introduced from the first inlet 11. The temperature of the COG introduced from the third inlet 51 may be, for example, 50 to 80°C. The COG, cooled by contact with the liquid 45 as it rises within the cooling tower 50, is discharged to the outside from a second outlet 58 provided at the top of the cooling tower 50 (packed bed 56). The temperature of the COG when it is discharged from the cooling tower 50 to the outside may be, for example, 35 to 50°C.

[0026] The liquid that comes into contact with the gas in the cooling tower 50 is recovered in a chimney tray 35 located below the packed bed 56. The gas cooling device 100 includes a third flow path 30 that leads the liquid 45 recovered in the chimney tray 35 out of the cooling tower 50 and introduces it into a liquid reservoir 52. The third flow path 30 leads the liquid 45 out from a third outlet 38 located above the chimney tray 35 and introduces the liquid 45 from a second inlet 32 ​​located in the liquid reservoir 52. The lead-out of the liquid 45 from the third outlet 38, the flow in the third flow path 30, and the introduction of the liquid 45 from the second inlet 32 ​​can be performed solely by the head pressure of the liquid 45. This reduces equipment costs and power costs.

[0027] The liquid reservoir 52 is divided into two sections, a first liquid reservoir 52A and a second liquid reservoir 52B, by an overflow weir 54, with different liquid levels. The first liquid reservoir 52A, located upstream, is designed to retain liquid due to the overflow weir 54. As a result, the liquid level 45 in the first liquid reservoir 52A is higher than that in the second liquid reservoir 52B, located downstream. The second inlet 32, into which the liquid 45 flowing through the third channel 30 is introduced, is located in the first liquid reservoir 52A. This allows the heat exchanger 20 to be sufficiently immersed in the liquid 45 retained in the first liquid reservoir 52A, even if the amount of liquid 45 in the cooling tower 50 fluctuates. This allows sufficient contact between the heat exchanger 20 and the liquid 45, whose temperature has risen due to contact with the gas.

[0028] The overflow weir 54 may be composed of a flat plate-shaped member, from which the liquid 45 overflows. However, it is not limited to this shape, and may be, for example, a plate-shaped member having a through hole through which the liquid 45 can flow. In this case, the liquid 45 overflows from the through hole. The liquid level of the first liquid reservoir 52A can be adjusted by the position of the through hole.

[0029] The second inlet 32, through which the liquid recovered in the chimney tray 35 is introduced, is located below the heat exchanger 20. The liquid 45 introduced from below the heat exchanger 20 flows toward the upper end of the overflow weir 54. As a result, the heat exchanger 20 and the liquid 45 introduced from the second inlet 32 ​​are in sufficient contact. Therefore, the liquid 45 used for circulation can be sufficiently cooled. From the viewpoint of further increasing the contact efficiency between the liquid introduced from the second inlet 32 ​​and the heat exchanger 20, the heat exchanger 20 may be positioned between the second inlet 32 ​​and the central part of the overflow weir 54 when the liquid reservoir 52 is viewed from above.

[0030] The liquid 45, which has been sufficiently cooled by contact with the heat exchanger 20 in the first liquid reservoir 52A, overflows beyond the upper end of the overflow weir 54 into the second liquid reservoir 52B. The second liquid reservoir 52B is provided with a first outlet 15 for guiding the liquid 45 into the first flow path 10. The liquid 45 that has overflowed into the second liquid reservoir 52B is guided out from the first outlet 15, flows through the first flow path 10, and is introduced into the interior of the cooling tower 50 from the first inlet 11, which is located above the packed bed 56.

[0031] The first channel 10 comprises a pipe 14 and a pump 12 for drawing in and discharging liquid 45. In the gas cooling system 100, the liquid 45 can be cooled using a heat exchanger 20 built into the cooling tower 50, so the first channel 10 does not need to have a heat exchanger. This eliminates the need for space to install a heat exchanger, and reduces the overall installation space of the gas cooling system 100. It also allows for a reduction in the capacity of the pump 12. Therefore, equipment costs and power costs can be reduced.

[0032] In the gas cooling system 102 of the second embodiment shown in Figure 2, the cooling tower 50A is provided with an expansion section 57 that extends horizontally (radially) at its lower end. The expansion section 57 is horizontally expanded compared to the rest of the cooling tower 50A. In the cooling tower 50A, the liquid reservoir section 52 is included in the expansion section 57. As a result, the volume of the liquid reservoir section 52 is larger than that of the cooling tower 50 in Figure 1. Therefore, the heat exchanger 20 located in the liquid reservoir section 52 can be made larger, allowing for smoother cooling of the liquid 45. In addition, the installation and maintenance of the heat exchanger 20 can be made smoother.

[0033] The size and position of the expansion portion 57 are not particularly limited. For example, in Figure 2, the portion including the liquid reservoir portion 52 is the expansion portion 57, but a structure in which a part of the liquid reservoir portion 52 is expanded is also possible. The gas cooling device 102 has the same configuration as the gas cooling device 100 of the first embodiment, except that the cooling tower 50A is equipped with the expansion portion 57. Therefore, the description of the gas cooling device 100 of the first embodiment can be applied.

[0034] The gas cooling device 103 of the third embodiment shown in Figure 3 includes a liquid level detection unit 37 for detecting the liquid level of the liquid 45 accumulating on the chimney tray 35, and a flow rate control valve 34 for adjusting the flow rate of the liquid 45 circulating in the third flow path 30. By adjusting the flow rate of the liquid 45 with the flow rate control valve 34, the liquid level of the liquid 45 accumulating on the chimney tray 35 may be controlled to a predetermined range. This prevents the liquid 45 from overflowing the chimney tray 35 and flowing down into the liquid reservoir 52, and allows a sufficiently large amount of liquid to be introduced into the liquid reservoir 52 via the third flow path 30. Therefore, the liquid can be efficiently cooled by the heat exchanger 20. The control of the liquid level of the liquid 45 accumulating on the chimney tray 35 may be performed, for example, by PID control.

[0035] The gas cooling device 103 has the same configuration as the gas cooling device 100 of the first embodiment, except that it includes a liquid level detection unit 37 and a flow control valve 34. Therefore, the description of the gas cooling device 100 of the first embodiment can be applied.

[0036] The gas cooling device 104 of the fourth embodiment shown in Figure 4 includes a liquid level detection unit 36 ​​for detecting the liquid level of the liquid 45 accumulating in the second liquid reservoir 52B, and a flow rate control valve 34 for adjusting the flow rate of the liquid 45 circulating in the third flow path 30. By adjusting the flow rate of the liquid 45 with the flow rate control valve 34, the liquid level of the liquid 45 accumulating in the second liquid reservoir 52B is controlled to a predetermined range. This makes it possible to sufficiently suppress, for example, the occurrence of cavitation and idling of the pump 12 provided in the first flow path 10. In particular, since the amount of liquid in the cooling tower 50 may fluctuate when starting operation of the gas cooling device 104 or during operating fluctuations, it is effective to adjust the flow rate of the liquid 45 with the flow rate control valve 34 so that the liquid level of the liquid 45 accumulating in the second liquid reservoir 52B is within a predetermined range in such cases. The control of the liquid level of the liquid 45 accumulating in the second liquid reservoir 52B may be performed by, for example, PID control.

[0037] The gas cooling device 104 has the same configuration as the gas cooling device 100 of the first embodiment, except that it includes a liquid level detection unit 36 ​​and a flow rate control valve 34. Therefore, the description of the gas cooling device 100 of the first embodiment can be applied.

[0038] Although several embodiments of the gas cooling system have been described, the gas cooling system of this disclosure is not limited to the above embodiments. For example, modifications may combine the configurations of each embodiment. That is, modifications of the third and fourth embodiments may include a cooling tower 50A having the extension 57 of the second embodiment instead of the cooling tower 50. Modification of the third embodiment may include a liquid level detection unit 36 ​​of the fourth embodiment along with the liquid level detection unit 37. In this case, for example, at the start of operation or during operating fluctuations, the flow rate of the flow control valve 34 may be adjusted based on the detection signal of the liquid level detection unit 36 ​​that detects the liquid level of the second liquid reservoir 52B, and during steady-state operation, the flow rate of the flow control valve 34 may be adjusted based on the liquid level detection unit 37 that detects the liquid level of the liquid 45 accumulating on the chimney tray 35.

[0039] In each of the above embodiments, the COG is cooled, but the gas to be cooled is not limited to the COG; it may be a gas containing the COG or a gas that does not contain the COG. Examples of such gases include boiler exhaust gas, blast furnace gas, and exhaust gas generated in other plants. Since COG cooling equipment is usually large, equipping the COG cooling equipment with a gas cooling device according to each of the above embodiments or its modifications can further reduce the installation space, as well as the pump introduction cost and power cost.

[0040] In the embodiments described above, the liquid 45 is circulated and used in all cases. Each gas cooling device may have a supply unit for replenishing the liquid 45 and / or a discharge unit for discharging the liquid 45, depending on the increase or decrease in the amount of circulating liquid 45. For example, when cooling a COG with saturated moisture concentration, the amount of liquid 45 increases, so the amount of liquid 45 may be adjusted by discharging the liquid 45 at the discharge unit. Also, the cooling towers 50, 50A have, for example, a cylindrical shape, but this shape is not particularly limited. It is not essential to provide the second inlet 32 ​​and the first outlet 15 on the side of the cooling towers 50, 50A, and they may be provided on the bottom of the cooling towers 50, 50A. The recovery of liquid within the cooling towers 50, 50A is not limited to the chimney tray 35. Any device capable of recovering at least a portion of the liquid 45 flowing down the inside of the cooling tower is acceptable.

[0041] In the modified versions of each embodiment, it is not necessary to provide an overflow weir 54 in the liquid reservoir 52. Alternatively, two or more overflow weirs 54 may be arranged in the liquid reservoir 52, dividing the liquid reservoir 52 into three or more sections. In this case, a heat exchanger 20 may be provided in each liquid reservoir 52.

[0042] A gas cooling method according to one embodiment is a gas cooling method that brings a gas and a liquid into countercurrent contact using a cooling tower, and comprises a cooling step of cooling the liquid with a heat exchanger provided in a liquid reservoir at the bottom of the cooling tower and supplied with a refrigerant from outside the cooling tower, and a circulation step of circulating the liquid by leading the liquid cooled by the heat exchanger out of the liquid reservoir and introducing the liquid from a first inlet provided above the liquid reservoir in the cooling tower.

[0043] The above method may include an introduction step of introducing the liquid recovered in a chimney tray provided between the liquid reservoir of the cooling tower and the first inlet from the cooling tower to the liquid reservoir of the cooling tower.

[0044] The gas cooling method described above may be carried out using any of the gas cooling devices 100, 102, 103, 104 described above or any of their variations. Therefore, the description of the gas cooling devices described above also applies to the gas cooling method of this embodiment.

[0045] For example, in a gas cooling method using any of the gas cooling devices 100, 102, 103, or 104, the cooling process may be performed in the first liquid reservoir 52A, which is located on the upstream side of the liquid reservoir 52, which is divided into multiple sections. After the cooling process, there may be an outflow process in which the liquid 45 cooled in the cooling process overflows through the overflow weir 54 and overflows into the second liquid reservoir 52B. After the outflow process, a circulation process may be performed in which the liquid is discharged from the first outlet 15 provided in the second liquid reservoir 52B.

[0046] For example, when using the gas cooling device 103 to cool the gas, a first detection step may be performed to detect the liquid level of the liquid 45 accumulating on the chimney tray 35, and a flow rate adjustment step may be performed to adjust the flow rate of the liquid 45 flowing through the third channel 30 based on the liquid level. This prevents the liquid 45 from overflowing the chimney tray 35 and flowing down into the liquid reservoir 52, and allows a sufficiently large amount of liquid to be introduced into the liquid reservoir 52 via the third channel 30. Therefore, the heat exchanger 20 can efficiently cool the liquid 45.

[0047] For example, when a gas cooling method is performed using a gas cooling device 104, a second detection step may be performed to detect the liquid level of the liquid 45 accumulating in the second liquid reservoir 52B, and a flow rate adjustment step may be performed to adjust the flow rate of the liquid 45 flowing through the third flow path 30 based on the liquid level. This makes it possible to sufficiently suppress, for example, the occurrence of cavitation and idling of the pump 12 provided in the first flow path 10.

[0048] In all of the above-described gas cooling methods, the liquid 45 in contact with the gas is cooled using a heat exchanger 20 installed in the liquid reservoir 52 (first liquid reservoir 52A) at the bottom of the cooling towers 50 and 50A. Therefore, the installation space can be reduced compared to when the heat exchanger is installed outside the cooling towers 50 and 50A. Furthermore, the liquid 45 in countercurrent contact with the gas can be cooled even without installing a heat exchanger in the first flow path 10. Consequently, it is possible to operate the system sufficiently even with a reduced pump capacity required for the liquid 45 to flow through the first flow path 10, thereby reducing the pump introduction cost and power cost.

[0049] The gas cooling method in this embodiment may be carried out using a gas cooling device different from the gas cooling devices 100, 102, 103, 104 and their modified variations described above.

[0050] Although several embodiments have been described above, this disclosure is not limited in any way to the embodiments described above. For example, in each of the embodiments described above, one packed bed 56 was provided in the cooling tower 50, but the packed bed 56 may be omitted, or two or more packed beds may be provided. [Industrial applicability]

[0051] According to this disclosure, it is possible to provide a gas cooling device and a gas cooling method that can reduce the installation space of the heat exchanger and reduce the introduction cost and power cost of the pump. [Explanation of symbols]

[0052] 10...First flow path, 11...First inlet, 12...Pump, 14...Piping, 15...First outlet, 20...Heat exchanger, 22...Second flow path, 30...Third flow path, 32...Second inlet, 34...Flow control valve, 35...Chimney tray, 36,37...Liquid level detection unit, 38...Third outlet, 45...Liquid, 50,50A...Cooling tower, 51...Third inlet, 52...Liquid reservoir, 52A...First liquid reservoir, 52B...Second liquid reservoir, 54...Overflow weir, 56...Packed bed, 57...Expansion section, 58...Second outlet, 100,102,103,104...Gas cooling device.

Claims

1. A gas cooling device that cools the gas by bringing it into countercurrent contact with a liquid, A cooling tower having a liquid reservoir at the bottom, A first channel is provided through which the liquid is discharged from the liquid reservoir and introduced into the cooling tower from a first inlet located above the liquid reservoir. A heat exchanger provided in the liquid reservoir for cooling the liquid, A second channel for supplying refrigerant to the heat exchanger, The system includes a third flow path that guides the liquid collected in a chimney tray, which is provided between the liquid reservoir and the first inlet, out of the cooling tower and into the liquid reservoir. The third flow path is a gas cooling device that introduces the liquid into the liquid reservoir from a second inlet located below the heat exchanger.

2. The gas cooling apparatus according to claim 1, wherein the cooling tower has an overflow weir in the liquid reservoir, and the heat exchanger is immersed in the liquid retained by the overflow weir.

3. The gas cooling apparatus according to claim 1 or 2, wherein the third flow path introduces the liquid recovered in the chimney tray into the liquid reservoir from the second inlet using only head pressure.

4. The gas cooling device according to any one of claims 1 to 3, wherein the third flow path has a flow control valve, and the flow rate of the liquid flowing through the third flow path is adjusted by the flow control valve to control the liquid level in the chimney tray within a predetermined range.

5. The first flow path has a pump, and the third flow path has a flow control valve. The gas cooling device according to any one of claims 1 to 4, wherein the flow rate of the liquid flowing through the third channel is controlled by the flow control valve to control the liquid level in the liquid reservoir to a predetermined range.

6. The gas cooling apparatus according to any one of claims 1 to 5, wherein the gas introduced into the cooling tower includes coke oven gas.

7. The gas cooling apparatus according to any one of claims 1 to 6, wherein at least a portion of the liquid reservoir extends horizontally more than the portion of the cooling tower other than the liquid reservoir.

8. A method for cooling a gas by bringing a gas and a liquid into countercurrent contact using a cooling tower, The process involves cooling the liquid using a heat exchanger provided in the liquid reservoir at the bottom of the cooling tower, which is supplied with a refrigerant from outside the cooling tower. The process involves discharging the liquid cooled by the heat exchanger from the liquid reservoir and circulating the liquid by introducing it through a first inlet located above the liquid reservoir in the cooling tower, A method for cooling a gas, comprising the steps of: discharging the liquid collected in a chimney tray provided between the liquid reservoir portion and the first inlet of the cooling tower from the cooling tower and introducing it into the liquid reservoir portion of the cooling tower.

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