Dry quenching diffused gas desulfurization and gas taking mode and control method

Abstract

The invention discloses a dry quenching diffused gas desulfurization and gas taking mode and a control method, and relates to the technical field of dry quenching processes. According to the coke dry quenching diffused gas desulfurization gas taking mode and the control method, the coke dry quenching environment dust removal waste gas is composed of three groups of common diffused circulating gas, coke loading waste gas and coke discharging waste gas. And coke charging, coke discharging and standby states are realized. According to the dry quenching diffused gas desulfurization gas taking mode and the control method, the problems of common diffused gas taking amount and stable operation of pressure control and regulation of a dry quenching furnace pre-storage chamber are solved. The gas taking point is determined to be between a fan and a cooler, and the requirement of the sodium bicarbonate desulfurization process for about 108-200 DEG C is met; a low-load butterfly valve sensitive in model selection and adjustment can quickly respond to the requirements of dry quenching furnace process adjustment and ensure stable operation of a desulfurization unit in a load range; and after gas taking, the diffused gas enters a working state and is self-adjusted by a variable frequency fan of a desulfurization system, so that the real essential safe operation of the dry quenching process and the environment-friendly and effective treatment of the diffused gas are realized.

Description

Technical Field

[0001] The invention relates to the technical field of dry coke quenching process, and in particular to a desulfurization and gas extraction mode and a control method for dry coke quenching vented gas. Background Art

[0002] The so-called dry quenching process is relative to wet quenching, which refers to a quenching process method that uses inert gas to cool down the red coke.

[0003] In the dry quenching process, red coke is loaded from the top of the dry quenching furnace, and low-temperature inert gas is blown into the red coke layer in the cooling section of the dry quenching furnace by the circulating fan to absorb the sensible heat of the red coke. The cooled coke is discharged from the bottom of the dry quenching furnace. The high-temperature inert gas coming out of the annular flue of the dry quenching furnace flows through the dry quenching boiler for heat exchange. The boiler generates steam, and the cooled inert gas is blown back into the dry quenching furnace by the circulating fan. The inert gas is recycled in a closed system. The dry quenching process is superior to wet quenching in terms of energy saving, environmental protection and improving coke quality.

[0004] In the prior art, it is difficult to control and adjust the amount of gas taken in and the pressure of the pre-storage chamber, which reduces the production accuracy and is more likely to cause safety accidents. Summary of the invention

[0005] 1. Technical issues to be resolved

[0006] In view of the deficiencies in the prior art, the present invention provides a desulfurization gas extraction method and a control method for CDQ vent gas, which solves the problems existing in the prior art.

[0007] (II) Technical solution

[0008] To achieve the above objectives, the present invention is implemented through the following technical solutions: a desulfurization gas extraction method and control method for CDQ vent gas, characterized in that: the specific conditions are as follows:

[0009] The dust removal waste gas in the CDQ environment is composed of three groups: ① Commonly used emission circulating gas, ② Coke loading waste gas, and ③ Coke discharge waste gas. In the coke loading, coke discharge and standby states, the gas volume fluctuates greatly, and the sulfur dioxide content also fluctuates in a peak and trough state. Its SO2 cannot meet the continuous standard, and the SO2 content is about 1000-1800mg / Nm3. In the coke loading state, it can reach up to 2000mg / Nm3 or more. Therefore, CDQ can only meet the emission standard requirements by adding sulfur dioxide removal facilities. The results of measuring the normal operation of the commonly used emission and dust removal fan alone: ​​the average SO2 concentration is above 1800mg / Nm3, and the environmental protection emission indicators exceed the standard;

[0010] Among them, the gas extraction position confirmation and main technical specifications are as follows:

[0011] Pipeline and valve size: The gas intake pipeline is selected to be Φ600mm or 700mm according to the load of CDQ. The process parameters are flow rate: 13000-20000Nm3 / h; pressure before valve: 4.5kPa(G); operating temperature: 170℃; rated Cv value: 42600.

[0012] Actuator air supply pressure (KPa) / voltage (V): 500KPa; air source / electrical interface: 1 / 2NPT; allowable pressure difference: 10.6kPa.

[0013] Positioner input signal: 4~20mA; output signal: with current feedback; air supply pressure: 400~500KPa; air source / electrical interface: 1 / 4NPT.

[0014] Adjustment control authority: dry quenching system control;

[0015] The installation requirements are as follows:

[0016] First, select a location between the CDQ circulating fan and the heat exchanger, and drill a hole to draw air out through a Φ600-700mm pipe.

[0017] Install a Φ600-700mm low-load butterfly valve on the outgoing pipe;

[0018] A sodium bicarbonate or activated coke desulfurization process is added to the rear end of the Φ600-700mm low-load butterfly valve, which requires a negative pressure design and an additional variable frequency fan for adjustment.

[0019] The original regulating valve for releasing gas is cancelled and replaced with an emergency pressure relief cut-off valve; the low-load butterfly valve enters the dry quenching operation screen control; the variable frequency fan is controlled by the desulfurization unit.

[0020] The two production units establish signal connection to monitor the operation dynamics of the dual processes in real time;

[0021] Among them, when working:

[0022] When the instrument air is greater than 0.3Mpa, the desulfurization fan is running, the circulating fan is running, the furnace cover is closed, and the regulating valve is in automatic mode, the regulating valve will automatically adjust according to PID; if any of the above conditions and signals are lost, the regulating valve will automatically switch to manual mode, and the valve will maintain the previous state. When the signal is restored, the valve will switch to automatic adjustment;

[0023] Among them, a low-load butterfly valve is established to participate in the dry quenching process control module:

[0024] After the low-load butterfly valve is put into operation, the opening degree of the best working condition is optimized; it can be quickly cut off in an emergency. The Hertz adjustment of the desulfurization variable frequency fan is frequently self-adjusted according to the pressure feedback of the dry coke pre-storage chamber.

[0025] (III) Beneficial effects

[0026] The present invention provides a desulfurization gas extraction method and control method for CDQ vent gas, which has the following beneficial effects:

[0027] The CDQ vent gas desulfurization gas extraction method and control method solves the problems of commonly used vent gas extraction volume and CDQ furnace pre-storage chamber pressure control and regulation for stable operation. The gas extraction point is determined to be between the fan and the cooler to meet the sodium bicarbonate desulfurization process requirements of about 108-200°C; the selection of a sensitive low-load butterfly valve can quickly respond to the needs of CDQ furnace process adjustments while ensuring stable operation within the load range of the desulfurization unit; after gas extraction, the vent gas enters the working state and is self-regulated by the variable frequency fan of the desulfurization system, realizing the truly essential safety operation of the CDQ process and the environmentally friendly and effective treatment of vent gas;

[0028] During the coke loading, coke discharge and standby states, the gas volume fluctuates greatly, and the sulfur dioxide content in the CDQ process also fluctuates in peaks and valleys. The focus is on solving the common vent gas intake volume and pre-storage chamber pressure control and regulation to ensure safe and reliable operation of the CDQ furnace process; the temperature and parameters of the intake gas meet the relevant operating requirements of the vent gas treatment sodium-based desulfurization, especially in terms of flow and temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic diagram of the waste gas composition of the dry coke quenching process of the present invention;

[0030] Figure 2 Schematic diagram of the gas extraction point of the present invention. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] See also Figure 1-2 The present invention provides a technical solution: a desulfurization gas extraction method and control method for CDQ vent gas, the specific situation is as follows:

[0033] The dust removal waste gas in the CDQ environment is composed of three groups: ① Commonly used emission circulating gas, ② Coke loading waste gas, and ③ Coke discharge waste gas. In the coke loading, coke discharge and standby states, the gas volume fluctuates greatly, and the sulfur dioxide content also fluctuates in a peak and trough state. Its SO2 cannot meet the continuous standard, and the SO2 content is about 1000-1800mg / Nm3. In the coke loading state, it can reach up to 2000mg / Nm3 or more. Therefore, CDQ can only meet the emission standard requirements by adding sulfur dioxide removal facilities. The results of measuring the normal operation of the commonly used emission and dust removal fan alone: ​​the average SO2 concentration is above 1800mg / Nm3, and the environmental protection emission indicators exceed the standard;

[0034] Among them, the gas extraction position confirmation and main technical specifications are as follows:

[0035] Pipeline and valve size: The gas intake pipeline is selected to be Φ600mm or 700mm according to the load of CDQ. The process parameters are flow rate: 13000-20000Nm3 / h; pressure before valve: 4.5kPa(G); operating temperature: 170℃; rated Cv value: 42600.

[0036] Actuator air supply pressure (KPa) / voltage (V): 500KPa; air source / electrical interface: 1 / 2NPT; allowable pressure difference: 10.6kPa.

[0037] Positioner input signal: 4~20mA; output signal: with current feedback; air supply pressure: 400~500KPa; air source / electrical interface: 1 / 4NPT.

[0038] Adjustment control authority: dry quenching system control;

[0039] The installation requirements are as follows:

[0040] First, select a location between the CDQ circulating fan and the heat exchanger, and drill a hole to draw air out through a Φ600-700mm pipe.

[0041] Install a Φ600-700mm low-load butterfly valve on the outgoing pipe;

[0042] A sodium bicarbonate or activated coke desulfurization process is added to the rear end of the Φ600-700mm low-load butterfly valve, which requires a negative pressure design and an additional variable frequency fan for adjustment.

[0043] The original regulating valve for releasing gas is cancelled and replaced with an emergency pressure relief cut-off valve; the low-load butterfly valve enters the dry quenching operation screen control; the variable frequency fan is controlled by the desulfurization unit.

[0044] The two production units establish signal connection to monitor the operation dynamics of the dual processes in real time;

[0045] Among them, when working:

[0046] When the instrument air is greater than 0.3Mpa, the desulfurization fan is running, the circulating fan is running, the furnace cover is closed, and the regulating valve is in automatic mode, the regulating valve will automatically adjust according to PID; if any of the above conditions and signals are lost, the regulating valve will automatically switch to manual mode, and the valve will maintain the previous state. When the signal is restored, the valve will switch to automatic adjustment;

[0047] Among them, a low-load butterfly valve is established to participate in the dry quenching process control module:

[0048] After the low-load butterfly valve is put into operation, the opening degree of the best working condition is optimized; it can be quickly cut off in an emergency. The Hertz adjustment of the desulfurization variable frequency fan is frequently self-adjusted according to the pressure feedback of the dry coke pre-storage chamber.

[0049] In summary, the CDQ vent gas desulfurization gas extraction method and control method solves the problems of commonly used vent gas extraction volume and CDQ furnace pre-storage chamber pressure control and regulation for stable operation. The gas extraction point is determined to be between the fan and the cooler to meet the sodium bicarbonate desulfurization process requirement of about 108-200°C; the selection of a low-load butterfly valve with sensitive adjustment can quickly respond to the needs of CDQ furnace process adjustment while ensuring stable operation within the load range of the desulfurization unit; after gas extraction, the vent gas enters the working state and is self-regulated by the variable frequency fan of the desulfurization system, realizing the truly essential safety operation of the CDQ process and the environmentally friendly and effective treatment of vent gas;

[0050] During the coke loading, coke discharge and standby states, the gas volume fluctuates greatly, and the sulfur dioxide content in the CDQ process also fluctuates in peaks and valleys. The focus is on solving the common vent gas intake volume and pre-storage chamber pressure control and regulation to ensure safe and reliable operation of the CDQ furnace process; the temperature and parameters of the intake gas meet the relevant operating requirements of the vent gas treatment sodium-based desulfurization, especially in terms of flow and temperature.

[0051] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0052] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method and control method for extracting desulfurized gas from CDQ vented gas, characterized in that: The details are as follows: The dust removal waste gas in the CDQ environment is composed of three groups: ① Commonly used emission circulating gas, ② Coke loading waste gas, and ③ Coke discharge waste gas. In the coke loading, coke discharge and standby states, the gas volume fluctuates greatly, and the sulfur dioxide content also fluctuates in a peak and trough state. Its SO2 cannot meet the continuous standard, and the SO2 content is about 1000-1800mg / Nm3. In the coke loading state, it can reach up to 2000mg / Nm3 or more. Therefore, CDQ can only meet the emission standard requirements by adding sulfur dioxide removal facilities. The results of measuring the normal operation of the commonly used emission and dust removal fan alone: ​​the average SO2 concentration is above 1800mg / Nm3, and the environmental protection emission indicators exceed the standard; Among them, the gas extraction position confirmation and main technical specifications are as follows: Pipeline and valve size: The gas intake pipeline is selected to be Φ600mm or 700mm according to the load of CDQ. The process parameters are flow rate: 13000-20000Nm3 / h; pressure before valve: 4.5kPa(G); operating temperature: 170℃; rated Cv value: 42600. Actuator air supply pressure (KPa) / voltage (V): 500KPa; air source / electrical interface: 1 / 2NPT; allowable pressure difference: 10.6kPa. Positioner input signal: 4~20mA; output signal: with current feedback; air supply pressure: 400~500KPa; air source / electrical interface: 1 / 4NPT. Adjustment control authority: dry coke quenching system control; The installation requirements are as follows: First, select a location between the CDQ circulating fan and the heat exchanger, and drill a hole to draw air out through a Φ600-700mm pipe. Install a Φ600-700mm low-load butterfly valve on the outgoing pipe; A sodium bicarbonate or activated coke desulfurization process is added to the rear end of the Φ600-700mm low-load butterfly valve, which requires a negative pressure design and an additional variable frequency fan for adjustment. The original regulating valve for releasing gas is cancelled and replaced with an emergency pressure relief cut-off valve; the low-load butterfly valve enters the dry quenching operation screen control; the variable frequency fan is controlled by the desulfurization unit. The two production units establish signal connection to monitor the operation dynamics of the dual processes in real time; Among them, when working: When the instrument air is greater than 0.3Mpa, the desulfurization fan is running, the circulating fan is running, the furnace cover is closed, and the regulating valve is in automatic mode, the regulating valve will automatically adjust according to PID; if any of the above conditions and signals are lost, the regulating valve will automatically switch to manual mode, and the valve will maintain the previous state. When the signal is restored, the valve will switch to automatic adjustment; Among them, a low-load butterfly valve is established to participate in the dry quenching process control module: After the low-load butterfly valve is put into operation, the opening degree of the best working condition is optimized; it can be quickly cut off in an emergency. The Hertz adjustment of the desulfurization variable frequency fan is frequently self-adjusted according to the pressure feedback of the dry coke pre-storage chamber.

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