WO2021128901A1

WO2021128901A1 - Primary cooling process and device utilizing circulating ammonia water refrigeration

Info

Publication number: WO2021128901A1
Application number: PCT/CN2020/111192
Authority: WO
Inventors: 李超; 李昊阳; 张爽; 张丹
Original assignee: 中冶焦耐(大连)工程技术有限公司
Priority date: 2019-12-23
Filing date: 2020-08-26
Publication date: 2021-07-01
Also published as: CN110903863A

Abstract

The present invention relates to a primary cooling process and device utilizing circulating ammonia water refrigeration, comprising a gas-liquid separator, a tar residue collecting device, a primary cooler, a lower condensate tank, a circulating ammonia water refrigeration unit, a tar residue pump, an emulsion spraying pump, a residual ammonia pump, a primary cooler condensate pump, a distilled ammonia removal unit pipeline, a tar delivery pipeline, a valve, a first-stage circulating ammonia tank, a second-stage circulating ammonia tank, a valve 1, a circulating ammonia pump, and a second-stage tar residue collecting device. The present invention has the following beneficial effects: by configuring the circulating ammonia water tanks in stages, an overly low temperature of circulating ammonia water entering the refrigeration unit can be avoided, while ensuring that the recycling temperature of the circulating ammonia water meets process requirements, thereby avoiding tar siltation in a gas collector, and so reducing the chance of blockage of a spray nozzle.

Description

Primary cooling process and device adopting circulating ammonia water refrigeration

Technical field

The invention relates to the technical field of coke oven gas purification, in particular to a preliminary cooling process and device using circulating ammonia water for refrigeration.

Background technique

During the coking process, the raw gas that escapes from the coking chamber of the coke oven through the riser is sprayed and cooled by circulating ammonia water to 80-85°C and then enters the gas-liquid separator for separation. The gas phase enters the primary cooler to continue cooling, and the liquid phase enters the circulating ammonia tank. . After the raw gas is cooled by the primary cooler, the condensate still enters the circulating ammonia tank, and the raw gas enters the electric tar capture unit. Most of the ammonia in the circulating ammonia tank is returned to the coke oven for spraying and cooling raw gas, and a small part is filtered into the ammonia distillation unit.

Although the ammonia water after gas-liquid separation is close to the raw gas temperature before entering the primary cooler, after mixing with the gas condensate in the primary cooler and the condensate of other sections, the temperature drops to 75-78°C. At present, the adopted circulating ammonia water refrigeration process is a process in which ammonia water is sent to the refrigeration unit to produce low-temperature water before returning to the coke oven, and then the ammonia water is returned to the coke oven to spray the raw gas to cool down. In practical applications, the temperature of the circulating ammonia water after the waste heat utilization of the refrigeration unit is reduced by 8-10°C. Although the cooling effect of the raw gas is enhanced due to the lowering of the circulating ammonia water spray temperature, it also leads to a decrease in the temperature of the circulating ammonia water after gas-liquid separation. This often makes the temperature of the circulating ammonia water after mixing the condensate less than 70°C, and after the waste heat of the refrigeration process is used, the temperature of the circulating ammonia water returning to the coke oven for spraying is generally less than 60°C. Due to the low temperature of the circulating ammonia water, the efficiency of the refrigeration unit is reduced, and the amount of low-temperature water produced is difficult to meet the process requirements, and because the temperature of the circulating ammonia water for spraying is too low, it will cause the tar in the raw gas to condense and block the nozzles, and even silt in the gas collector.

Summary of the invention

In order to overcome the disadvantages of the prior art, the technical problem solved by the present invention is to provide a primary cooling process and device using circulating ammonia water for refrigeration. The circulating ammonia tank is set up in stages, which can avoid the temperature of the circulating ammonia water entering the refrigeration unit from being too low while at the same time. Ensure that the recycling temperature of the circulating ammonia water meets the process requirements, avoid tar accumulation in the gas collector, and reduce the probability of clogging of the spray nozzle.

In order to achieve the above objectives, the present invention adopts the following technical solutions to achieve:

A primary cooling device adopting circulating ammonia water refrigeration, including a gas-liquid separator, a tar residue collecting device, a primary cooler, a lower condensate tank, a circulating ammonia water refrigeration unit, a tar residue pump, an emulsion spraying pump, a residual ammonia water pump, and a primary cooling device. The condenser condensate pump, the ammonia removal unit pipeline, the tar delivery pipeline, the valve, the primary circulating ammonia tank, the secondary circulating ammonia tank, the valve one, the circulating ammonia pump and the secondary tar residue collection device, are characterized in that: The middle part of the gas-liquid separator is provided with an inlet connected to the raw gas outlet of the coke oven system, the top part is provided with a gas phase outlet connected with the raw gas inlet on the upper left side of the primary cooler, and the bottom part is provided with a liquid phase outlet connected to a tar residue collection device;

The left middle part of the primary cooler is provided with an upper condensate outlet connected to the secondary tar residue collecting device, the lower left part is provided with a lower condensate outlet connected to the lower condensate tank, and the middle and upper right part is connected to the second stage through an emulsion spray pump. The first-stage circulating ammonia tank is connected, the middle and lower left part is connected to the lower condensate tank through the primary cooler condensate pump, and the bottom is provided with a raw gas outlet;

The top of the tar residue collection device is provided with a tar residue inlet through a tar residue pump connected to the tar outlet at the bottom of the secondary circulating ammonia tank, and the lower left side is provided with a circulating ammonia outlet which is connected to the primary circulating ammonia tank and the secondary circulating ammonia tank respectively. Circulating ammonia water inlet connection provided;

The lower left part of the secondary tar residue collecting device is provided with a condensate outlet connected to the upper condensate inlet of the secondary circulating ammonia tank, and the upper part is provided with a circulating ammonia inlet through valve 1 between the gas-liquid separator and the tar residue collecting device. Connection pipe connection;

The middle and upper part of the primary circulating ammonia tank is provided with a circulating ammonia outlet connected to the inlet of the circulating ammonia pump, and the middle of the right part is provided with a tar outlet connected with the tar outlet provided in the middle of the secondary circulating ammonia tank and merged with the tar delivery pipeline Connected, the bottom of the tar residue outlet is connected with the tar residue outlet at the bottom of the secondary circulating ammonia tank;

The outlet of the circulating ammonia pump is respectively connected with the valve inlet and the inlet of the circulating ammonia refrigerating unit, and the valve outlet is connected with the outlet of the circulating ammonia refrigerating unit and then connected with the coke oven system;

The middle part of the two-stage circulating ammonia tank is provided with a waste water inlet and a lower condensate inlet connected to the outlet of the primary cooler condensate pump in sequence from bottom to top on the right side of the secondary circulating ammonia tank. Ammonia unit pipeline connection.

A preliminary cooling process adopting circulating ammonia water refrigeration, including the following steps:

1) The raw gas from the coke oven system is sprayed and cooled by circulating ammonia water and enters the gas-liquid separator for separation in the form of gas-liquid mixture. The raw gas flows upwards in the gas phase into the primary cooler for cooling, and the circulating ammonia enters the tar in the form of liquid phase. The slag collection device or the secondary tar residue collection device, the circulating ammonia water in the tar residue collection device enters the primary circulation ammonia tank and the secondary circulation ammonia tank, and the circulating ammonia water in the secondary tar residue collection device only enters the secondary circulation ammonia tank. Regular cleaning of the tar residue in the tar residue collection device and the secondary tar residue collection device;

2) The raw gas entering the upper section of the primary cooler is cooled by circulating water. The raw gas flows downwards through the primary cooler broken tray and enters the lower section of the primary cooler. The condensate accumulates on the broken tray and enters the secondary through the upper condensate outlet. Tar residue collection device; the raw gas in the lower section of the primary cooler is cooled by low-temperature water and flows out from the raw gas outlet at the bottom of the primary cooler and is sent to the electric raw gas trapping device. The condensate from the lower section of the primary cooler enters the lower condensate tank through the lower condensate outlet , The condensate in the lower condensate tank passes through the primary cooler condensate pump, part of which is used for spraying in the lower section of the primary cooler, and the other part is transported to the secondary circulating ammonia tank;

3) The first-level circulating ammonia tank only receives the circulating ammonia water discharged from the tar residue collection device. The circulating ammonia water in the first-level circulating ammonia tank passes through the circulating ammonia pump part to enter the refrigeration unit for refrigeration, and the other part is not refrigerated through the valve bypass pipe The recycled ammonia water is combined and returned to the coke oven system;

4) The secondary circulating ammonia tank not only receives the circulating ammonia water discharged from the tar residue collection device, but also the circulating ammonia water discharged from the secondary tar residue collection device, the wastewater from other sections of the wastewater inlet, and the condensate from the lower section of the primary cooler. The emulsion in the second-stage circulating ammonia tank is returned to the upper section of the primary cooler through the emulsion spray pump for spray washing, and the ammonia in the second-stage circulating ammonia tank is transported to the ammonia distillation device through the remaining ammonia pump through the ammonia removal unit pipeline;

5) The tar in the primary circulating ammonia tank and the secondary circulating ammonia tank are discharged and merged through their respective tar ports, and then sent out through the tar delivery pipeline. The tar residue in the primary circulating ammonia tank and the secondary circulating ammonia tank passes through their bottoms. The tar residue port is transported to the tar residue collection device by the tar residue pump.

Compared with the prior art, the beneficial effects of the present invention are:

1) Avoid too low temperature of the circulating ammonia water entering the refrigeration unit, reduce the investment of the circulating ammonia water refrigeration unit, and improve the thermal efficiency of the circulating ammonia water refrigeration unit;

2) The recycling temperature of the circulating ammonia water is high enough to avoid tar accumulation in the gas collector and reduce the clogging of the spray nozzle.

Description of the drawings

Figure 1 is a schematic diagram of the process flow of the present invention.

In the figure: 1-coke oven system 2-gas-liquid separator 3-tar slag collection device 4-primary cooler 5-lower condensate tank 6-circulating ammonia water refrigeration unit 7-tar slag pump 8-emulsion spray pump 9- Remaining ammonia pump 10-primary cooler condensate pump 11-de-electricity and raw gas capture 12-waste water inlet 13-ammonia removal unit pipeline 14-tar outgoing pipeline 15-valve 16-primary circulation ammonia tank 17-secondary circulation Ammonia tank 18-valve 1 19-circulating ammonia pump 20-secondary tar residue collection device

Detailed ways

The specific embodiments of the present invention will be further described below in conjunction with the accompanying drawings. In order to make the presentation clearer, the "up", "middle", "down", "left" and "right" in the description are only those shown in the drawings. The orientation (location) is a reference, and does not necessarily refer to the actual orientation (location) of the object:

As shown in Figure 1, the present invention relates to a primary cooling device using circulating ammonia water refrigeration, including a gas-liquid separator 2, a tar residue collecting device 3, a primary cooler 4, a lower condensate tank 5, and a circulating ammonia water refrigeration unit 6 , Tar residue pump 7, emulsion spray pump 8, residual ammonia water pump 9, primary cooler condensate pump 10, ammonia removal unit pipeline 13, tar delivery pipeline 14, valve 15, primary circulation ammonia tank 16, secondary Circulating ammonia tank 17, valve one 18, circulating ammonia pump 19 and secondary tar residue collecting device 20. The gas-liquid separator 2 has an inlet connected to the raw gas outlet of the coke oven system 1 in the middle, and a gas-phase outlet is provided on the top. The raw gas inlet on the upper left side of the primary cooler 4 is connected, and the bottom is provided with a liquid phase outlet connected to the tar residue collection device 3;

The left middle part of the primary cooler 4 is provided with an upper condensate outlet connected to the secondary tar residue collecting device 20, the lower left part is provided with a lower condensate outlet connected to the lower condensate tank 5, and the right middle upper part is sprayed by emulsion The pump 8 is connected to the secondary circulating ammonia tank 17, the left middle and lower part is connected to the lower condensate tank 5 through the primary cooler condensate pump 10, and the raw gas outlet is provided at the bottom to send the raw gas after washing and cooling to the electricity for raw gas capture 11 devices;

The top of the tar residue collecting device 3 is provided with a tar residue inlet through the tar residue pump 7 to connect with the tar outlet at the bottom of the secondary circulating ammonia tank 17, and the lower left side is provided with a circulating ammonia outlet which is connected to the primary circulating ammonia tank 16 and the secondary ammonia tank respectively. The circulating ammonia water inlet connection provided on the circulating ammonia tank 17;

The lower left part of the secondary tar residue collecting device 20 is provided with a condensate outlet connected to the upper condensate inlet of the secondary circulating ammonia tank 17, and the upper part is provided with a circulating ammonia inlet through valve 18 and gas-liquid separator 2 to collect tar residue. The connection pipe connection between the devices 3;

The middle and upper left side of the primary circulating ammonia tank 16 is provided with a circulating ammonia outlet connected to the inlet of the circulating ammonia pump 19, and the middle right part is provided with a tar outlet connected with the tar outlet provided in the middle of the secondary circulating ammonia tank 17 to merge with the tar. The outgoing pipeline 14 is connected, and the tar residue outlet is provided at the bottom to connect with the tar residue outlet provided at the bottom of the secondary circulating ammonia tank 17;

The outlet of the circulating ammonia pump 19 is connected to the inlet of the valve 15 and the inlet of the circulating ammonia refrigerating unit 6 respectively, and the outlet of the valve 15 is connected to the outlet of the circulating ammonia refrigerating unit 6 and then connected to the coke oven system 1;

The secondary circulating ammonia tank 17 is provided with a waste water inlet 12 and a lower condensate inlet connected to the outlet of the primary cooler condensate pump 10 in the middle of the right side of the secondary circulating ammonia tank 17 from bottom to top, and the left upper part is provided with a remaining ammonia water outlet through the remaining ammonia water pump 9 is connected to the pipeline 13 of the ammonia removal unit, and sends the remaining ammonia water to the ammonia removal unit.

1) The raw gas from the coke oven system 1 sprayed and cooled by the circulating ammonia water enters the gas-liquid separator 2 in the form of gas-liquid mixture for separation. The raw gas flows upward in the gas phase into the primary cooler 4 for cooling, and the circulating ammonia water is in the liquid phase. The form enters the tar residue collection device 3 or the secondary tar residue collection device 20, the circulating ammonia in the tar residue collection device 3 enters the primary circulation ammonia tank 16 and the secondary circulation ammonia tank 17, and the circulation in the secondary tar residue collection device 20 The ammonia water only enters the secondary circulating ammonia tank 17, and the tar residue in the tar residue collection device 3 and the secondary tar residue collection device 20 are cleaned regularly;

2) The raw gas entering the upper section of the primary cooler 4 is cooled by circulating water, and the raw gas flows downwards through the broken tray of the primary cooler 4 and enters the lower section of the primary cooler. The condensate accumulates on the broken tray and enters through the upper condensate outlet Secondary tar residue collection device 20; the raw gas in the lower section of the primary cooler 4 is cooled by low-temperature water and flows out from the raw gas outlet at the bottom of the primary cooler 4 and is sent to the electric raw gas 11 device. The condensate in the lower section of the primary cooler 4 is condensed in the lower section The liquid outlet enters the lower condensate tank 5, and the condensate in the lower condensate tank 5 passes through the primary cooler condensate pump 10, part of which is used for spraying in the lower section of the primary cooler 4, and the other part is delivered to the secondary circulating ammonia tank 17;

3) The first-level circulating ammonia tank 16 only receives the circulating ammonia water discharged from the tar residue collection device 3. The circulating ammonia in the first-level circulating ammonia tank 16 passes through the circulating ammonia pump 19 and enters the refrigeration unit 6 for refrigeration, and the other part passes through the valve 15 The circulating ammonia water that has not been refrigerated in the bypass pipeline is combined and returned to the coke oven system 1 for circulating spraying;

4) The secondary circulating ammonia tank 17 not only receives a small part of the circulating ammonia discharged from the tar residue collection device 3, but also receives the circulating ammonia discharged from the secondary tar residue collection device 20, the wastewater from other sections of the wastewater inlet 12, and the primary cooling The condensate in the lower section of the reactor 4, the emulsion in the secondary circulating ammonia tank 17 is returned to the primary cooler through the emulsion spray pump 8. The upper section is sprayed and washed, and the ammonia in the secondary circulating ammonia tank 17 is removed by the residual ammonia pump 9 The ammonia distillation unit pipeline 13 is transported to the ammonia distillation device;

5) The tar in the primary circulating ammonia tank 16 and the secondary circulating ammonia tank 17 are discharged and merged through their respective tar ports, and then sent out through the tar delivery pipeline 14. The tar in the primary circulating ammonia tank 16 and the secondary circulating ammonia tank 17 The tar residue is transported by the tar residue pump 7 to the tar residue collecting device 3 through the tar residue port at the bottom of each.

Claims

A primary cooling device adopting circulating ammonia water refrigeration, including a gas-liquid separator, a tar residue collecting device, a primary cooler, a lower condensate tank, a circulating ammonia water refrigeration unit, a tar residue pump, an emulsion spraying pump, a residual ammonia water pump, and a primary cooling device. The condenser condensate pump, the ammonia removal unit pipeline, the tar delivery pipeline, the valve, the primary circulating ammonia tank, the secondary circulating ammonia tank, the valve one, the circulating ammonia pump and the secondary tar residue collection device, are characterized in that: The middle part of the gas-liquid separator is provided with an inlet connected to the raw gas outlet of the coke oven system, the top part is provided with a gas phase outlet connected with the raw gas inlet on the upper left side of the primary cooler, and the bottom part is provided with a liquid phase outlet connected to a tar residue collection device;

The left middle part of the primary cooler is provided with an upper condensate outlet connected to the secondary tar residue collecting device, the lower left part is provided with a lower condensate outlet connected to the lower condensate tank, and the middle and upper right part is connected to the second stage through an emulsion spray pump. The first-stage circulating ammonia tank is connected, the middle and lower left part is connected to the lower condensate tank through the primary cooler condensate pump, and the bottom is provided with a raw gas outlet;

The top of the tar residue collection device is provided with a tar residue inlet through a tar residue pump connected to the tar outlet at the bottom of the secondary circulating ammonia tank, and the lower left side is provided with a circulating ammonia outlet which is connected to the primary circulating ammonia tank and the secondary circulating ammonia tank respectively. Circulating ammonia water inlet connection provided;

The lower left part of the secondary tar residue collecting device is provided with a condensate outlet connected to the upper condensate inlet of the secondary circulating ammonia tank, and the upper part is provided with a circulating ammonia inlet through valve 1 between the gas-liquid separator and the tar residue collecting device. Connection pipe connection;

The middle and upper part of the primary circulating ammonia tank is provided with a circulating ammonia outlet connected to the inlet of the circulating ammonia pump, and the middle of the right part is provided with a tar outlet connected with the tar outlet provided in the middle of the secondary circulating ammonia tank and merged with the tar delivery pipeline Connected, the bottom of the tar residue outlet is connected with the tar residue outlet at the bottom of the secondary circulating ammonia tank;

The outlet of the circulating ammonia pump is respectively connected with the valve inlet and the inlet of the circulating ammonia refrigerating unit, and the valve outlet is connected with the outlet of the circulating ammonia refrigerating unit and then connected with the coke oven system;

The middle part of the two-stage circulating ammonia tank is provided with a waste water inlet and a lower condensate inlet connected to the outlet of the primary cooler condensate pump in sequence from bottom to top on the right side of the secondary circulating ammonia tank. Ammonia unit pipeline connection.
A primary cooling process adopting circulating ammonia water for refrigeration according to claim 1, characterized in that it comprises the following steps:

1) The raw gas from the coke oven system is sprayed and cooled by circulating ammonia water and enters the gas-liquid separator for separation in the form of gas-liquid mixture. The raw gas flows upwards in the gas phase into the primary cooler for cooling, and the circulating ammonia enters the tar in the form of liquid phase. The slag collection device or the secondary tar residue collection device, the circulating ammonia water in the tar residue collection device enters the primary circulation ammonia tank and the secondary circulation ammonia tank, the circulating ammonia water in the secondary tar residue collection device enters the secondary circulation ammonia tank, and the tar Regular cleaning of the tar residue in the slag collection device and the secondary tar residue collection device;

2) The raw gas entering the upper section of the primary cooler is cooled by circulating water. The raw gas flows downwards through the primary cooler broken tray and enters the lower section of the primary cooler. The condensate accumulates on the broken tray and enters the secondary through the upper condensate outlet. Tar residue collection device; the raw gas in the lower section of the primary cooler is cooled by low-temperature water and flows out from the raw gas outlet at the bottom of the primary cooler and is sent to the electric raw gas trapping device. The condensate from the lower section of the primary cooler enters the lower condensate tank through the lower condensate outlet , The condensate in the lower condensate tank passes through the primary cooler condensate pump, part of which is used for spraying in the lower section of the primary cooler, and the other part is transported to the secondary circulating ammonia tank;

3) The first-level circulating ammonia tank only receives the circulating ammonia water discharged from the tar residue collection device. The circulating ammonia water in the first-level circulating ammonia tank passes through the circulating ammonia pump part to enter the refrigeration unit for refrigeration, and the other part is not refrigerated through the valve bypass pipe The recycled ammonia water is combined and returned to the coke oven system;

4) The secondary circulating ammonia tank not only receives the circulating ammonia water discharged from the tar residue collection device, but also the circulating ammonia water discharged from the secondary tar residue collection device, the wastewater from other sections of the wastewater inlet, and the condensate from the lower section of the primary cooler. The emulsion in the second-stage circulating ammonia tank is returned to the upper section of the primary cooler through the emulsion spray pump for spray washing, and the ammonia in the second-stage circulating ammonia tank is transported to the ammonia distillation device through the remaining ammonia pump through the ammonia removal unit pipeline;

5) The tar in the primary circulating ammonia tank and the secondary circulating ammonia tank are discharged and merged through their respective tar ports, and then sent out through the tar delivery pipeline. The tar residue in the primary circulating ammonia tank and the secondary circulating ammonia tank passes through their bottoms. The tar residue port is transported to the tar residue collection device by the tar residue pump.