CN117339385A - Feed gas treatment system and feed gas treatment method - Google Patents

Abstract

The invention discloses a feed gas treatment system and a feed gas treatment method, wherein the treatment system comprises: an air inlet unit provided with an air inlet amount monitoring module for monitoring the volume flow of the raw material gas which is fed into the catalytic oxidation unit, wherein the raw material gas is inert gas containing reducing gas impurities capable of reacting with oxygen; the oxygenation unit is provided with an air inflow control module for monitoring and adjusting the volume flow of oxygen introduced into the catalytic oxidation unit; a catalytic oxidation unit, wherein the reducing gas impurities and oxygen in the raw material gas undergo oxidation reaction in the catalytic oxidation unit to obtain purified gas; the control unit is connected with the air inflow monitoring module and the air inflow control module; the control unit controls the air inflow control module to adjust the volume flow of the oxygen according to the concentration of the reducing gas impurities in the raw material gas. The control unit controls the air inflow control module to adjust the volume flow of the oxygen which is introduced into the catalytic oxidation unit once at intervals of T according to the change of the oxygen concentration of the purified gas.

Description

Raw gas treatment system and raw gas treatment method

Technical field

The present disclosure relates to the technical field of gas purification, and specifically to a raw material gas treatment system and a raw material gas treatment method.

Background technique

High-purity inert gases are indispensable raw materials for electronics, medical and other industries. Inert gas raw gas, such as _N2 raw gas, contains reducing gas impurities such as methane, carbon monoxide, and hydrogen. Only after the raw gas is purified can high-purity inert gas that meets the standards be obtained. The purification of the raw gas mainly includes high-temperature catalytic oxidation and adsorption. Two steps. The catalytic oxidation reaction of impurities in the feed gas is carried out in a high-temperature (300°C) catalytic unit. The impurities in the feed gas react with oxygen to generate water and carbon dioxide. The catalytic reaction of the impurities is as follows:

CH ₄ +2O ₂ →2H ₂ O+CO ₂

2CO+O ₂ →2CO ₂

2H ₂ +O ₂ →2H ₂ O

The gas after the catalytic reaction of the high-temperature catalytic unit continues to be passed into the normal-temperature adsorption unit at the back end, and the purified N ₂ is obtained after adsorbing water, carbon dioxide and oxygen in the adsorption unit. There are at least two adsorption units. When one of them is saturated, it switches to the other to continue adsorption. The saturated adsorption unit starts the regeneration process for regeneration. After regeneration, it waits for the next switch. This cycle continues to achieve the purpose of uninterrupted air supply. .

High-temperature catalytic reactions require oxygen. Although the feed gas itself contains oxygen, the oxygen content fluctuates greatly, and the oxygen content in the feed gas is not enough to re-oxidize the metal elements in the reduced state in the high-temperature catalytic unit into catalytically active metal oxidizers. Therefore, the metal oxide catalyst in the high-temperature catalytic unit may be continuously reduced to metal elements by reducing impurities during the reaction process, and eventually all catalytic activity will be lost, and methane, hydrogen and carbon monoxide impurities in the gas cannot be removed, affecting downstream processes.

Therefore, additional oxygen addition is required during the actual high-temperature catalytic step to prevent the above situation. In the inert gas purification system, oxygen is added into the high-temperature catalytic reaction unit through the pressure regulating valve and flow restrictor. The oxygen intake volume is controlled by controlling the pressure at the inlet end of the flow restrictor, and then through the float air intake meter. Displays air intake volume. There are two drawbacks to supplying oxygen in this way:

1. The pressure regulating valve and flow limiter can only be controlled manually and cannot be automatically controlled. When the intake volume of raw gas increases, the content of methane in it also increases. If the intake volume of oxygen supply remains unchanged at this time, the high-temperature catalytic reaction between methane and oxygen will be insufficient, impurities will not be removed cleanly, and the purity requirements will not be met, which may seriously cause Back-end products are scrapped;

When the feed gas intake volume decreases, the actual oxygen consumption of the high-temperature catalytic unit also decreases. If the supply oxygen supply volume remains unchanged at this time, excess oxygen will enter the adsorption unit, causing the adsorption unit to quickly reach saturation, shortening the adsorption unit's lifespan. cycle period. Although the cycle period of the adsorption unit can be extended by increasing the volume of the adsorption unit, the cost will also increase. When the adsorption unit is saturated due to high concentration of oxygen, oxygen impurities will enter the back-end process pipeline, affecting the purity of the inert gas, and even causing the back-end product to be scrapped.

2. The oxygen intake volume is displayed through the float air intake meter, which is greatly affected by the pressure of oxygen. Since the calibration pressure of the float air intake meter is a fixed value, when the actual oxygen pressure fluctuates greatly, the air intake display is inaccurate, and the actual air intake volume is too large or too small, resulting in inaccurate oxygen addition, which can easily lead to oxygen or Methane impurities exceed the standard.

Contents of the invention

Based on this, the purpose of the present disclosure is to accurately control the amount of oxygen introduced into the high-temperature catalytic unit during the purification process of the inert gas feed gas.

In order to achieve the above objectives, the present disclosure provides a raw material gas treatment system, including:

The air intake unit is provided with an air intake volume monitoring module. The air intake volume monitoring module is used to monitor the volume flow rate of the raw material gas that passes into the catalytic oxidation unit. The raw material gas contains reducing gas impurities that can react with oxygen. inert gas;

The oxygenation unit is provided with an air intake control module, and the air intake control module is used to monitor and adjust the volume flow rate of oxygen flowing into the catalytic oxidation unit;

A catalytic oxidation unit, in which the reducing gas impurities and the oxygen in the feed gas undergo an oxidation reaction to obtain purified gas;

A control unit, connected to the air intake monitoring module and the air intake control module, controls the air intake control module to adjust the volume flow rate of the oxygen according to the concentration of the reducing gas impurities in the raw material gas;

The control unit also controls the air intake control module to adjust the volume flow rate A of oxygen flowing into the catalytic oxidation unit according to changes in the oxygen concentration of the purified gas at intervals T:

When residual oxygen is detected in the purified gas after the time interval T, the volume flow rate A is adjusted to: the volume flow rate of oxygen flowing into the catalytic oxidation unit before the time interval T minus the volume flow rate after the time interval T. Describe the volume flow rate of oxygen in the purified gas;

When no oxygen is detected in the purified gas after the time interval T, the volume flow rate A is adjusted to: the oxygen volume flow rate introduced into the catalytic oxidation unit before the time interval T plus the purified gas decreases after the time interval T oxygen volume flow rate.

Preferably, when no oxygen is detected in the purified gas after the time interval T and the oxygen volume flow rate is not reduced when adjusted before the time interval T, then the volume flow rate A is adjusted to: introduce catalytic oxidation before the time interval T The oxygen volume flow rate of the unit is added to the corresponding volume flow reduction amount when the oxygen volume flow rate decreases in the most recent adjustment.

Preferably, the feed gas contains at least two of the reducing gas impurities.

Preferably, the control unit calculates the volumetric flow rate of oxygen in the following manner:

Calculate the oxygen volume ratio required for the complete oxidation reaction of each reducing gas impurity according to the volume ratio of each reducing gas impurity in the raw material gas,

Then, the sum of the oxygen volume ratios corresponding to the complete oxidation reaction of each reducing gas impurity is multiplied by the volume flow rate of the raw material gas.

Preferably, the feed gas includes high-purity nitrogen or ultra-high-purity nitrogen in CB/T8979.

Preferably, the method further includes a detection unit connected to the control unit and at least used to detect the oxygen concentration of the feed gas before the catalytic oxidation reaction and the oxygen concentration of the purified gas obtained after the catalytic oxidation reaction.

More preferably, the control unit controls the air intake control module to adjust the volume flow rate of oxygen flowing into the catalytic oxidation unit every time interval T according to changes in the oxygen concentration of the purified gas. .

More preferably, the volumetric flow rate of oxygen is:

The oxygen volume flow calculated by the control unit is added to the compensation coefficient, and the value of the compensation coefficient is the volume flow corresponding to oxygen of 0 to 0.2 ppm.

In order to achieve the above object, the present disclosure also provides a raw material gas treatment method performed in the aforementioned raw material gas treatment system, including the following steps:

S1. The air intake monitoring module in the air intake unit feeds back the monitored volume flow rate a of the raw gas to the control unit;

S2. The control unit calculates the volume flow rate A of oxygen required to react with the reducing gas impurity in the volume flow rate a according to the concentration of the reducing gas impurity in the raw gas;

S3. The control unit controls the air intake control module in the oxygenation unit to adjust the volume flow rate of oxygen to the volume flow rate A.

Preferably, the control unit calculates the volumetric flow rate A in the following manner:

Calculate the oxygen volume ratio required for the complete oxidation reaction of each reducing gas impurity according to the volume ratio of each reducing gas impurity in the raw material gas, and then calculate the oxygen volume ratio required for the complete oxidation reaction of each reducing gas impurity. The sum of the corresponding oxygen volume ratios is multiplied by the volume flow rate of the feed gas.

More preferably, it also includes the step of adjusting the volume flow rate A every time interval T:

The detection unit detects the oxygen concentration of the purified gas obtained after the catalytic oxidation reaction at intervals T and feeds the results back to the control unit.

The control unit compares the oxygen concentration of the purified gas before and after the time interval T,

When residual oxygen is detected in the purified gas after the time interval T, the volume flow rate A is adjusted to: the volume flow rate of oxygen flowing into the catalytic oxidation unit before the time interval T minus the volume flow rate after the time interval T. Describe the volume flow rate of oxygen in the purified gas;

When no oxygen is detected in the purified gas after the time interval T, the volume flow rate A is adjusted to: the oxygen volume flow rate introduced into the catalytic oxidation unit before the time interval T plus the purified gas decreases after the time interval T oxygen volume flow rate;

When no oxygen is detected in the purified gas after the time interval T and the oxygen volume flow rate is not reduced when adjusted before the time interval T, then the volume flow rate A is adjusted to: the oxygen flowing into the catalytic oxidation unit before the time interval T The volume flow rate is added to the corresponding decrease in volume flow rate when the oxygen volume flow rate decreases in the latest adjustment.

More preferably, the step of compensating the volumetric flow rate of oxygen is also included:

The volume flow rate A is: the sum of the oxygen volume flow rate calculated by the control unit and the compensation coefficient. The value of the compensation coefficient is the volume flow rate corresponding to oxygen of 0 to 0.2 ppm.

The technical solution claimed in this disclosure has achieved the following beneficial effects:

1) The linkage between the oxygen adding unit and the raw gas inlet unit is realized, which can automatically adjust the volume flow rate of oxygen required for catalytic oxidation according to the volume flow rate of the raw gas and the concentration of reducing gas impurities in it, and accurately control the amount of oxygen added to avoid Excessive or insufficient oxygen addition ensures the full reaction of reducing gas impurities and oxygen while ensuring the stability of the purification system operation.

2) The detection unit detects the oxygen concentration of the raw gas before and after catalytic oxidation, and calculates and controls the actual required amount of oxygen based on the change in oxygen concentration in the purified gas obtained after catalytic oxidation, further Achieving precise control of the amount of oxygen.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the drawings needed to be used in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only embodiments of the present disclosure. Those of ordinary skill in the art can also obtain other drawings based on the provided drawings without exerting creative efforts.

Figure 1 is a schematic diagram of an inert gas purification device including a raw gas treatment system.

Figure 2 is a module diagram of the raw gas treatment system.

Reference signs:

1-Mass flow meter; 2-Manual isolation valve; 3-First inlet pressure sensor; 4-First manual valve; 5-Mass flow controller; 6-Second manual valve; 7-Filter; 8- Pressure regulating valve with meter; 9-second inlet pressure sensor; 10-one-way valve; 11-pneumatic diaphragm valve; 12-normal temperature adsorption tank; 13-heat exchange unit; 14-catalytic oxidation unit.

Detailed ways

In order to make the purpose, technical solutions and beneficial effects of the embodiments of the present disclosure clearer, the technical solutions in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings in the embodiments of the present disclosure. Obviously, the described The embodiments are some, but not all, of the embodiments of the present disclosure. Based on the embodiments in this disclosure, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of this disclosure.

Example 1

The raw gas treatment system in this embodiment is used in inert gas purification. Referring to Figures 1 and 2, the oxygenation system in this embodiment includes an air intake unit, an oxygenation unit, a catalytic oxidation unit and a control unit. The air intake unit and the oxygenation unit are respectively connected to the catalytic oxidation unit.

The air intake unit is provided with an air intake monitoring module for monitoring the volume flow rate of the inert gas feed gas flowing into the catalytic oxidation unit. The air intake monitoring module is preferably a mass flow meter 1 . In a preferred solution, the air inlet pipeline of the air inlet unit is also provided with a branch circuit, and the branch circuit is provided with a pressure monitoring module and a branch circuit switch for monitoring the inlet pressure of the raw gas.

Exemplarily, the air intake unit is specifically provided with a manual isolation valve 2 , a first air intake pressure sensor 3 and a mass flow meter 1 . The manual isolation valve 2 and the mass flow meter 1 are set on the main air intake pipeline. The manual isolation valve 2 is used to open and close the raw gas in the intake unit pipeline, and the mass flow meter 1 is used to monitor the inert gas raw material flowing into the catalytic oxidation unit. The gas volume flow rate is measured and the monitoring results are fed back to the control unit in real time. The first intake pressure sensor 3 is disposed on a branch of the intake unit pipeline and is used to monitor the intake pressure of the intake unit pipeline. There is also a first manual valve 4 on the branch of the air intake unit pipeline, which is used to open and close the branch. When the first air intake pressure sensor 3 is damaged, the manual valve can be closed and replaced without affecting the raw materials. gas supply.

The oxygenation unit is provided with an air intake control module for monitoring and regulating the volume flow of oxygen flowing into the catalytic oxidation unit. The air intake control module is preferably a mass flow controller 5 . In a preferred solution, the gas inlet side of the air intake control module is also provided with a filter module for filtering impurities in oxygen, a pressure adjustment module for adjusting the gas pressure at the inlet end of the air intake control module, and a user interface in order according to the air intake direction. A pressure monitoring module for monitoring the gas pressure at the inlet of the air intake control module.

For example, the pipeline of the oxygenation unit may be provided with a second manual valve 6, a filter 7, a pressure regulating valve with a meter 8, a second intake pressure sensor 9, and a mass flow controller 5 in order according to the air inlet direction. , one-way valve 10 and pneumatic diaphragm valve 11.

Among them, the second manual valve 6 is used to control the oxygen switch. Filter 7 is used to filter oxygen particles to prevent them from damaging the mass flow controller. The pressure regulating valve 8 with a meter is used to adjust the pressure at the inlet end of the mass flow controller 5 to ensure that the pressure is within the required pressure range. The pressure gauge is used to observe the pressure after oxygen pressure regulation to prevent the oxygen pressure from being unable to be determined after the second intake pressure sensor 9 fails. The second inlet pressure sensor 9 is used to monitor whether the pressure at the inlet end of the mass flow controller 5 is within the working pressure range. When overpressure or pressure decrease occurs, an alarm signal is provided and an alarm is issued through the alarm system. The one-way valve 10 is used to prevent the raw material gas from flowing back into the oxygen pipeline. The pneumatic diaphragm valve 11 is used for automatic switching of oxygen addition.

The catalytic oxidation unit is a place where the oxidation reaction occurs under the action of high temperature and catalyst from the reducing gas impurities in the feed gas and the oxygen from the oxygen addition unit. Since nitrogen is the most commonly used inert protective gas in industry, it is used as protective gas and carrier gas in the manufacturing of integrated circuit semiconductors and electronic vacuum devices. Therefore, for example, in this embodiment, the raw material gas is high-purity nitrogen in GB/T 8979-2008, and the reducing gas impurities are hydrogen, methane and carbon monoxide. The concentrations of hydrogen, methane and carbon monoxide are calculated based on the maximum concentrations of hydrogen, methane and carbon monoxide contained in high-purity nitrogen in GB/T 8979-2008.

The control unit uses a PLC (Programmable Logic Controller, programmable logic controller). The control unit is connected to the air intake monitoring module and the air intake control module. The concentrations of hydrogen, methane and carbon monoxide are also preset in the control unit. The air intake monitoring module and the air intake control module respectively feed back the monitored volume flow a of the raw gas and the volume flow of oxygen to the control unit through a 4-20mA signal in real time. The control unit determines the concentration of reducing gas impurities in the raw gas. , calculate the volume flow rate A of oxygen required to react with the reducing gas impurities in the raw material gas with volume flow rate a, and give a control signal to control the proportional solenoid valve of the mass flow controller to adjust the oxygen intake volume to the volume flow rate A, while the mass flow controller feedbacks the flow rate through the thermal flow monitoring function. When the flow rate fed back by the mass flow controller is different from the control flow rate of the control unit, an abnormal oxygen flow alarm is given, thereby closing the pneumatic diaphragm valve 11 to prevent excess oxygen from entering the back end and affecting the purity of the process gas. In a preferred solution, the control unit controls the air intake amount control module to adjust the oxygen intake amount every time interval T according to the volume flow change of the raw gas.

Specifically, the impurity concentrations of high-purity nitrogen in GB/T 8979-2008 are as shown in the table below.

The following high-temperature catalytic reactions occur in the catalytic oxidation unit:

CH ₄ +2O ₂ →2H ₂ O+CO ₂

2CO+O ₂ →2CO ₂

2H ₂ +O ₂ →2H ₂ O

In this embodiment, it is assumed that all gases are ideal gases under standard conditions, so the molar ratio of the gases can be directly expressed as a volume ratio. The control unit can calculate the oxygen volume ratio required for the complete oxidation reaction of each reducing gas impurity based on the volume ratio of each reducing gas impurity in the raw gas, and then calculate the oxygen volume ratio corresponding to the complete oxidation reaction of each reducing gas impurity. The volume flow rate of oxygen can be calculated by adding and multiplying the volume flow rate of the raw gas.

According to the above reaction equation, the amount of oxygen added is calculated based on the maximum reducing gas impurity content. Since there is less oxygen in the air separation feed gas, and to ensure the operational stability of the purification system, the oxygen in the feed gas is ignored. Therefore, 1ppmCH ₄ needs to add 2ppmO ₂ , 1ppmCO needs to add 0.5ppmO ₂ , and 1ppmH ₂ needs to add 0.5ppmO ₂ , that is, the maximum oxygen amount is 3ppmO ₂ .

ppm is the mole fraction or volume fraction of the gas. The PLC calculates the amount of oxygen required in the limit state (the state with the largest amount of reducing gas impurities) based on the raw gas volume flow rate fed back by the mass flow meter 1, and then controls the mass flow control. The device adjusts the volume flow of oxygen to avoid insufficient or excessive oxygen addition. The accuracy of the oxygen mass flow controller control is to adjust the flow rate once per minute to improve the accuracy of the oxygen flow rate and the stability of the purification.

For example, when the volume flow rate of nitrogen Q=60Nm³/H, the volume flow rate Q per unit time is 1000slm (standard liter per minute, standard liter/minute), and the oxygen flow rate S of _3ppm O2 is: 1000×3× 10 ^-6 sml=3×10 ^-3 sml=3 sccm (standard milliliter/minute). If the volume flow rate of raw gas measured by mass flow meter 1 changes, it can be calculated according to the above formula. Write the calculation formula into the PLC control program to automatically calculate the oxygen flow rate based on the flow rate of the raw gas, thereby adjusting and controlling the oxygen volume flow rate to ensure the accuracy of the oxygen flow rate and the stability of the purification system.

Of course, in addition to nitrogen, the oxygen addition calculation method in this embodiment is also applicable to other inert gases, such as helium, neon, argon, krypton or xenon. The concentration of reducing gas impurities can be referred to the respective countries. standard.

This embodiment realizes the linkage between the oxygen adding unit and the raw gas inlet unit, can automatically adjust the flow rate of oxygen according to the flow rate of the raw gas, accurately controls the amount of oxygen added, avoids excessive or insufficient oxygen addition, and ensures the purity of the purified gas. Stability of the purification process.

The oxygenation and purification process performed in the inert gas purification system including the oxygenation system in this embodiment includes the following steps:

S1. The raw material gas passes through the manual isolation valve 2/bellows valve and enters the heat exchange unit 13 through the air intake unit for heat exchange and then enters the catalytic oxidation unit 14 for high-temperature catalytic reaction. The air intake monitoring module in the air intake unit will monitor the raw material The gas volume flow a is fed back to the control unit;

S2. The control unit calculates the volume flow rate A of oxygen required to react with the reducing gas impurity in the volume flow rate a according to the concentration of the reducing gas impurity in the raw gas;

S3. The control unit controls the air intake control module in the oxygen adding unit to adjust the volume flow rate of oxygen to the volume flow rate A. The oxygen enters the pipeline of the oxygen adding unit through the second manual valve 6 and passes through the filter 7 and the unit. The valve 10 and the pneumatic diaphragm valve 11 enter the catalytic oxidation unit.

In a more preferred solution, it also includes a step of compensating the volume flow rate of oxygen flowing into the catalytic oxidation unit: adding a compensation coefficient to the oxygen volume flow rate calculated by the control unit, and the compensation coefficient can be set to 0 to 0.2 ppm of oxygen. The corresponding volume flow rate is preferably set to the volume flow rate corresponding to 0.1 ppm oxygen to compensate for the lack of oxygen due to instrument deviation.

After the high-temperature catalytic reaction of the raw gas is completed, it enters the heat exchange unit again to exchange heat with the incoming air. After heat exchange, it enters the normal temperature adsorption tank 12 through the pneumatic valve for adsorption and purification, and then enters the back-end user process equipment through the pneumatic valve.

Example 2

The raw material gas treatment system in this embodiment is provided with a detection unit for detecting the concentration of reducing gas impurities and the oxygen concentration of the raw material gas before and after the catalytic oxidation reaction, such as an oxygen analyzer, a chromatograph and other detection devices. For the settings, please refer to Embodiment 1.

The detection unit is connected to the control system and feeds back the detected data on the concentration of reducing gas impurities and the concentration of oxygen in the raw gas before the catalytic oxidation reaction and the oxygen concentration of the purified gas obtained after the catalytic oxidation reaction to the 4-20mA signal. control unit.

In this embodiment, the inert gas is also exemplarily selected from high-purity nitrogen in GB/T 8979-2008, and the reducing gas impurities include hydrogen, methane and carbon monoxide. Of course, the system of this embodiment can also be used for the purification of other inert gases. The calculation method of the initial oxygen volume flow rate flowing into the catalytic oxidation unit is also the same as in Example 1:

Calculate the oxygen volume ratio required for the complete oxidation reaction of each reducing gas impurity based on the volume ratio of each reducing gas impurity in the raw material gas, and then add the oxygen volume ratio corresponding to the complete oxidation reaction of each reducing gas impurity. Multiplied by the volume flow rate of the raw material gas, the volume flow rate of oxygen can be obtained.

However, in this embodiment, the control unit will subsequently control the air intake control module to accurately adjust the volume flow of oxygen based on the change in oxygen concentration in the purified gas fed back by the detection unit at every time interval T.

The oxygenation and purification process performed in the inert gas purification system including the raw gas treatment system in this embodiment includes the following steps:

S0. The detection unit detects the concentration of reducing gas impurities and the original oxygen concentration in the raw gas, as well as the oxygen concentration of the raw gas after the catalytic oxidation reaction and feeds it back to the control unit;

S1. The raw material gas passes through the manual isolation valve 2/bellows valve and enters the heat exchange unit 13 through the air intake unit for heat exchange and then enters the catalytic oxidation unit 14 for high-temperature catalytic reaction. The air intake monitoring module in the air intake unit will monitor the raw material The gas volume flow a is fed back to the control unit;

S2. The control unit calculates the volume flow rate A of oxygen required to react with the reducing gas impurity in the volume flow rate a according to the concentration of the reducing gas impurity in the raw gas;

S3. The control unit controls the air intake control module in the oxygen adding unit to adjust the volume flow of oxygen to volume flow A. The oxygen enters the pipeline of the oxygen adding unit through the second manual valve 6 and passes through the filter 7 and the one-way valve. 10 and pneumatic diaphragm valve 11 enter the catalytic oxidation unit;

S4. The control unit controls the air intake volume control module to accurately adjust the oxygen volume flow rate every time interval T (such as one minute) according to the change in oxygen concentration in the purified gas:

The detection unit detects the oxygen concentration of the purified gas obtained after the catalytic oxidation reaction at every time interval T and feeds the results back to the control unit.

The control unit compares the oxygen concentration of the purified gas before and after the time interval T,

When residual oxygen is detected in the purified gas after the time interval T, the volume flow rate A is adjusted to: the volume flow rate of oxygen flowing into the catalytic oxidation unit before the time interval T minus the oxygen in the purified gas after the time interval T. volumetric flow;

When no oxygen is detected in the purified gas after the time interval T, the volume flow rate A is adjusted to: the oxygen volume flow rate introduced into the catalytic oxidation unit before the time interval T plus the reduced oxygen volume flow rate of the purified gas after the time interval T ;

When no oxygen is detected in the purified gas after the time interval T and the oxygen volume flow rate is not reduced when adjusted before the time interval T, then the volume flow rate A is adjusted to: the oxygen volume flow rate flowing into the catalytic oxidation unit before the time interval T Add the decrease in oxygen volume flow in the previous adjustment, that is, add the decrease in volume flow corresponding to the decrease in oxygen volume flow in the latest adjustment.

In this embodiment, the oxygen volume flow rate adjusted before the time interval T is used for the catalytic oxidation reaction within the time range T, and the oxygen volume flow rate adjusted after the time interval T is used for the catalytic oxidation reaction within the next time range T.

After the high-temperature catalytic reaction of the raw gas is completed, it enters the heat exchange unit again to exchange heat with the incoming air. After heat exchange, it enters the normal temperature adsorption tank 12 through the pneumatic valve for adsorption and purification, and then enters the back-end user process equipment through the pneumatic valve.

In a more preferred solution, this embodiment also includes the step of compensating the volume flow rate of oxygen flowing into the catalytic oxidation unit: adding a compensation coefficient to the oxygen volume flow rate calculated by the control unit, and the compensation coefficient can be set to 0~ The volume flow rate corresponding to 0.2 ppm oxygen is preferably set to the volume flow rate corresponding to 0.1 ppm oxygen to compensate for the lack of oxygen due to instrument deviation.

This embodiment uses a set detection unit to detect the actual oxygen concentration of the raw material gas before and after catalytic oxidation, and calculates and controls the actual required oxygen addition based on the change in the oxygen concentration of the raw material gas after catalytic oxidation. The operation is more flexible, further achieving precise control of the oxygen amount.

The above-described embodiments are only illustrative descriptions of the present disclosure and do not limit the scope of the present disclosure. Those of ordinary skill in the art may make various modifications to the technical solutions of the present disclosure without departing from the design spirit of the present disclosure. and improvements should fall within the protection scope determined by this disclosure.

Claims (10)

1. A raw material gas treatment system, characterized in that it includes The air intake unit is provided with an air intake volume monitoring module. The air intake volume monitoring module is used to monitor the volume flow rate of the raw material gas that passes into the catalytic oxidation unit. The raw material gas contains reducing gas impurities that can react with oxygen. inert gas; The oxygenation unit is provided with an air intake control module, and the air intake control module is used to monitor and adjust the volume flow rate of oxygen flowing into the catalytic oxidation unit; A catalytic oxidation unit, in which the reducing gas impurities and the oxygen in the feed gas undergo an oxidation reaction to obtain purified gas; A control unit, connected to the air intake monitoring module and the air intake control module, controls the air intake control module to adjust the volume flow rate of the oxygen according to the concentration of the reducing gas impurities in the raw material gas; The control unit controls the air intake control module to adjust the volume flow rate A of oxygen flowing into the catalytic oxidation unit according to the change in the oxygen concentration of the purified gas every time interval T: When residual oxygen is detected in the purified gas after the time interval T, the volume flow rate A is adjusted to: the volume flow rate of oxygen flowing into the catalytic oxidation unit before the time interval T minus all the oxygen after the time interval T. Describe the volume flow rate of oxygen in the purified gas; When no oxygen is detected in the purified gas after the time interval T, the volume flow rate A is adjusted to: the oxygen volume flow rate introduced into the catalytic oxidation unit before the time interval T plus the purified gas decreases after the time interval T oxygen volume flow rate. 2. The raw material gas treatment system according to claim 1, characterized in that when no oxygen is detected in the purified gas after the time interval T and the oxygen volume flow rate is not reduced when adjusting before the time interval T, then the oxygen volume flow rate will be reduced. The volume flow rate A is adjusted as follows: the volume flow rate of oxygen flowing into the catalytic oxidation unit before the time interval T plus the corresponding decrease in volume flow rate when the oxygen volume flow rate decreases in the latest adjustment. 3. The raw material gas treatment system according to claim 1, characterized in that the raw material gas contains at least two kinds of reducing gas impurities; The control unit calculates the volumetric flow rate of oxygen as follows: Calculate the oxygen volume ratio required for the complete oxidation reaction of each reducing gas impurity according to the volume ratio of each reducing gas impurity in the raw material gas, Then, the sum of the oxygen volume ratios corresponding to the complete oxidation reaction of each reducing gas impurity is multiplied by the volume flow rate of the raw material gas. 4. The raw material gas treatment system according to claim 3, characterized in that the raw material gas includes high-purity nitrogen or ultra-high-purity nitrogen in CB/T8979. 5. The raw material gas treatment system according to claim 3, further comprising a detection unit connected to the control unit and at least used to detect the oxygen concentration and oxygen concentration of the raw material gas before the catalytic oxidation reaction. The oxygen concentration of the purified gas obtained after catalytic oxidation reaction. 6. The raw material gas treatment system according to claim 5, characterized in that the volume flow rate of the oxygen is: The oxygen volume flow calculated by the control unit is added to the compensation coefficient, and the value of the compensation coefficient is the volume flow corresponding to oxygen of 0 to 0.2 ppm. 7. A raw material gas treatment method carried out in the raw material gas treatment system according to any one of claims 1 to 6, characterized in that it includes the following steps: S1. The air intake monitoring module in the air intake unit feeds back the monitored volume flow rate a of the raw gas to the control unit; S2. The control unit calculates the volume flow rate A of oxygen required to react with the reducing gas impurity in the volume flow rate a according to the concentration of the reducing gas impurity in the raw gas; S3. The control unit controls the air intake control module in the oxygenation unit to adjust the volume flow rate of oxygen to the volume flow rate A. 8. The raw material gas treatment method according to claim 7, characterized in that the control unit calculates the volume flow rate A in the following manner: Calculate the oxygen volume ratio required for the complete oxidation reaction of each reducing gas impurity according to the volume ratio of each reducing gas impurity in the raw material gas, and then calculate the oxygen volume ratio required for the complete oxidation reaction of each reducing gas impurity. The sum of the corresponding oxygen volume ratios is multiplied by the volume flow rate of the feed gas. 9. The raw material gas treatment method according to claim 8, further comprising the step of adjusting the volume flow rate A every time interval T: The detection unit detects the oxygen concentration of the purified gas obtained after the catalytic oxidation reaction at intervals T and feeds the results back to the control unit. The control unit compares the oxygen concentration of the purified gas before and after the time interval T, When residual oxygen is detected in the purified gas after the time interval T, the volume flow rate A is adjusted to: the volume flow rate of oxygen flowing into the catalytic oxidation unit before the time interval T minus all the oxygen after the time interval T. Describe the volume flow rate of oxygen in the purified gas; When no oxygen is detected in the purified gas after the time interval T, the volume flow rate A is adjusted to: the oxygen volume flow rate introduced into the catalytic oxidation unit before the time interval T plus the purified gas decreases after the time interval T oxygen volume flow rate; When no oxygen is detected in the purified gas after the time interval T and the oxygen volume flow rate is not reduced when adjusted before the time interval T, then the volume flow rate A is adjusted to: the oxygen flow into the catalytic oxidation unit before the time interval T The volume flow rate is added to the corresponding decrease in volume flow rate when the oxygen volume flow rate decreases in the latest adjustment. 10. The raw material gas treatment method according to claim 7, further comprising the step of compensating the volume flow rate of oxygen: The volume flow rate A is: the sum of the oxygen volume flow rate calculated by the control unit and the compensation coefficient. The value of the compensation coefficient is the volume flow rate corresponding to oxygen of 0 to 0.2 ppm.