PSA pressure swing adsorption oxygen and nitrogen production integrated system and method for simultaneously producing nitrogen and oxygen
Technical Field
The invention belongs to the technical field of gas separation, and particularly relates to a PSA pressure swing adsorption oxygen and nitrogen production integrated system and a method for simultaneously producing nitrogen and oxygen.
Background
In the existing PSA pressure swing adsorption process flow, independent nitrogen production and independent oxygen production are adopted, and generally, the evacuation treatment is carried out on the nitrogen-rich waste gas for producing nitrogen and the nitrogen-rich waste gas for producing oxygen. The compressed air is not fully utilized and recycled. This greatly increases the production cost per cubic volume of nitrogen and oxygen. Although the technological process is applied and perfected for a long time, the above-mentioned disadvantages are still avoided.
Disclosure of Invention
The invention aims to solve the technical problem of providing a PSA pressure swing adsorption oxygen and nitrogen generation integrated system and a method for simultaneously generating nitrogen and oxygen. The PSA pressure swing adsorption oxygen and nitrogen production integrated system can simultaneously extract nitrogen and oxygen, can also switch to independently extract nitrogen or oxygen according to needs, can fully improve the recovery rate and the utilization rate of raw material air, and can simultaneously prepare high-purity nitrogen and high-concentration oxygen.
In order to solve the technical problems, the invention adopts the following technical scheme: a PSA pressure swing adsorption nitrogen and oxygen production integrated system at least comprises two nitrogen production adsorption separation tanks, two oxygen production adsorption separation tanks, a nitrogen production process storage tank, an oxygen production process storage tank, various control valves, connecting pipelines and a program controller, wherein the control valves comprise a raw material air inlet valve for nitrogen production, a waste gas evacuation three-position five-way middle seal valve, a raw material air inlet valve for oxygen production, a waste gas evacuation three-position five-way middle seal valve and a product air outlet three-position three-way middle through valve for nitrogen production, the product for oxygen generation gives vent to anger three-position tee bend well logical valve, system nitrogen with seal valve in the pressure-equalizing three-position tee bend, system oxygen with seal valve in the pressure-equalizing three-position tee bend, system nitrogen with pressure-equalizing high selection valve, system oxygen with pressure-equalizing high selection valve, system nitrogen with pressure-equalizing low selection valve, system oxygen with pressure-equalizing low selection valve, system nitrogen with washing needle valve and system oxygen with washing needle valve, these control valve and pipeline, absorption separation jar between constitute following return circuit:
a pressure-boosting adsorption loop: including input pipeline and corresponding to first system nitrogen adsorption and separation jar, second system nitrogen adsorption and separation jar, first system oxygen adsorption and separation jar, second system oxygen adsorption and separation jar, system nitrogen technology storage tank and the switching valve of system oxygen technology storage tank: the device comprises a raw material air inlet valve for nitrogen making, a waste gas evacuation three-position five-way middle seal valve, a raw material air inlet valve for oxygen making, a waste gas evacuation three-position five-way middle seal valve, a product air outlet three-position three-way middle through valve for nitrogen making and a product air outlet three-position three-way middle through valve for oxygen making;
a pressure equalizing loop: including input pipeline and corresponding to first system nitrogen adsorption and separation jar, second system nitrogen adsorption and separation jar, first system oxygen adsorption and separation jar and the switching valve of second system oxygen adsorption and separation jar: a pressure equalizing high-pressure selection valve for nitrogen making, a pressure equalizing high-pressure selection valve for oxygen making, a pressure equalizing three-position three-way middle sealing valve for nitrogen making, a pressure equalizing three-position three-way middle sealing valve for oxygen making, a pressure equalizing low-pressure selection valve for nitrogen making and a pressure equalizing low-pressure selection valve for oxygen making.
The raw material air inlet and waste gas exhaust for nitrogen and oxygen production are controlled by a three-position five-way middle seal valve for nitrogen and waste gas exhaust, a raw material air inlet for oxygen production and a waste gas exhaust three-position five-way middle seal valve through a process controller.
The product gas outlet for nitrogen and oxygen production adopts the product gas outlet three-position three-way middle through valve for nitrogen production and the product gas outlet three-position three-way middle through valve for oxygen production to achieve the output of the product nitrogen and oxygen and the pressure equalization on the process through the nitrogen production process storage tank and the oxygen production process storage tank.
And the oxygen-enriched waste gas in the first nitrogen-making adsorption separation tank is subjected to pressure equalization by a pressure equalization high-selection valve for nitrogen making, a pressure equalization three-position three-way middle-sealing valve for nitrogen making and a pressure equalization low-selection valve for oxygen making.
And the nitrogen-rich waste gas in the second oxygen production adsorption separation tank is subjected to pressure equalization by a pressure equalization high-selection valve for oxygen production, a pressure equalization three-position three-way middle-sealing valve for oxygen production and a pressure equalization low-selection valve for nitrogen production to carry out pressure equalization on the second nitrogen production adsorption separation tank.
And the oxygen-enriched waste gas in the second nitrogen-making adsorption separation tank is subjected to pressure equalization by a pressure equalization high-selection valve for nitrogen making, a pressure equalization three-position three-way middle-sealing valve for nitrogen making and a pressure equalization low-selection valve for oxygen making to the second oxygen-making adsorption separation tank.
And the nitrogen-rich waste gas in the first oxygen production adsorption separation tank is subjected to pressure equalization by a pressure equalization high-selection valve for oxygen production, a pressure equalization three-position three-way middle-sealing valve for oxygen production and a pressure equalization low-selection valve for nitrogen production to carry out pressure equalization on the first nitrogen production adsorption separation tank.
The integrated system can simultaneously produce nitrogen and oxygen, and can produce nitrogen and oxygen independently or oxygen independently.
The method for simultaneously preparing nitrogen and oxygen by the PSA pressure swing adsorption nitrogen and oxygen preparation integrated system comprises the following steps:
(1) the first pressure-boosting adsorption process:
a. the dry air after being pretreated, deoiled and dewatered enters a first nitrogen-making adsorption separation tank through a raw material inlet valve for nitrogen making and a waste gas emptying three-position five-way middle seal valve to adsorb oxygen, and unadsorbed nitrogen outputs product nitrogen through a product outlet three-position three-way middle seal valve for nitrogen making and a nitrogen-making process storage tank;
b. the dry air after being pretreated, deoiled and dewatered enters a second oxygen generation adsorption separation tank through a raw material inlet three-position five-way middle seal valve for oxygen generation and a waste gas emptying three-position five-way middle seal valve to adsorb nitrogen, and unadsorbed oxygen outputs product oxygen through a product outlet three-position three-way middle seal valve for oxygen generation and an oxygen generation process storage tank;
c. residual gas in the second nitrogen-making adsorption separation tank is directly discharged into the atmosphere through a raw material gas inlet and waste gas evacuation three-position five-way middle seal valve for nitrogen making;
d. residual gas in the first oxygen production adsorption separation tank is directly discharged into the atmosphere through a raw material inlet for oxygen production and a waste gas evacuation three-position five-way middle seal valve;
(2) the first pressure equalizing process:
a. the first nitrogen making adsorption separation tank and the second nitrogen making adsorption separation tank are conducted through a three-position three-way middle-way valve for nitrogen making product gas outlet to finish pressure equalizing on nitrogen gas, and meanwhile, the first oxygen making adsorption separation tank and the second oxygen making adsorption separation tank are conducted through a three-position three-way middle-way valve for oxygen making product gas outlet to finish pressure equalizing on oxygen gas;
b. the oxygen-enriched waste gas in the first nitrogen-making adsorption separation tank is subjected to lower pressure equalization on the first oxygen-making adsorption separation tank through a pressure equalization high-selection valve for nitrogen making, a pressure equalization three-position three-way middle-sealing valve for nitrogen making and a pressure equalization low-selection valve for oxygen making; meanwhile, nitrogen-rich waste gas in the second oxygen production adsorption separation tank is subjected to lower pressure equalization on the second nitrogen production adsorption separation tank through a pressure equalization high-selection valve for oxygen production, a pressure equalization three-position three-way middle-sealing valve for oxygen production and a pressure equalization low-selection valve for nitrogen production;
(3) and (3) a second pressure-boosting adsorption process:
a. the dry air after being pretreated, deoiled and dewatered enters a second nitrogen-making adsorption separation tank through a three-position and five-way middle-seal valve for raw material air inlet and waste gas evacuation for nitrogen making to adsorb oxygen, and unadsorbed nitrogen outputs product nitrogen through a product air outlet three-position and three-way middle-seal valve for nitrogen making and a storage tank of a nitrogen making process;
b. the dry air after being pretreated, deoiled and dewatered enters a first oxygen production adsorption separation tank through a raw material inlet valve for oxygen production and a waste gas evacuation three-position five-way middle seal valve to adsorb nitrogen, and unadsorbed oxygen outputs product oxygen through a product outlet three-position three-way middle seal valve for oxygen production and an oxygen production process storage tank;
c. residual air pressure in the first nitrogen-making adsorption separation tank is directly discharged into the atmosphere through a raw material air inlet for nitrogen making and a waste gas evacuation three-position five-way middle seal valve;
d. the residual air pressure in the second oxygen-making adsorption separation tank is directly discharged into the atmosphere through a raw material air inlet for oxygen making and a waste gas emptying three-position five-way middle seal valve;
(4) and (3) a second pressure equalizing process:
a. the first nitrogen-making adsorption separation tank and the second nitrogen-making adsorption separation tank are conducted by a three-position three-way middle-way valve for nitrogen-making product gas outlet to finish nitrogen upper pressure equalization; the first oxygen-making adsorption separation tank and the second oxygen-making adsorption separation tank are conducted by a three-position three-way middle-way valve for oxygen-making product gas outlet to finish oxygen pressure equalizing;
b. the oxygen-enriched waste gas in the second nitrogen-making adsorption separation tank is subjected to lower pressure equalization on the second oxygen-making adsorption separation tank through a pressure equalization high-selection valve for nitrogen making, a pressure equalization three-position three-way middle-sealing valve for nitrogen making and a pressure equalization low-selection valve for oxygen making; meanwhile, nitrogen-rich waste gas in the first oxygen production adsorption separation tank is subjected to pressure equalization by a pressure equalization high-selection valve for oxygen production, a pressure equalization three-position three-way middle-sealing valve for oxygen production and a pressure equalization low-selection valve for nitrogen production, and the first nitrogen production adsorption separation tank is subjected to pressure equalization.
Compared with the prior art, the invention has the following advantages:
the PSA pressure swing adsorption oxygen and nitrogen production integrated system can simultaneously extract two products of nitrogen and oxygen, can be used in occasions requiring nitrogen and oxygen at the same time, can independently extract nitrogen or oxygen by switching a program controller according to requirements, can produce large-scale single product of nitrogen or oxygen by a multi-tower process, can fully improve the recovery rate and the utilization rate of raw material air, and achieves the final purposes of energy conservation and consumption reduction.
Drawings
FIG. 1 is a diagram showing the state of the system in the first pressure-increasing adsorption process for simultaneous oxygen and nitrogen production in example 1.
FIG. 2 is a state diagram of the system during the first pressure equalization for simultaneous oxygen and nitrogen production in example 1.
FIG. 3 is a diagram showing the state of the system in the second pressure-increasing adsorption process in the simultaneous oxygen and nitrogen production in example 1.
FIG. 4 is a state diagram of the system in the second pressure equalization process in the simultaneous oxygen and nitrogen production in example 1.
FIG. 5 is a diagram showing the state of the system in the adsorption process by column A in the case of producing nitrogen alone in example 2.
FIG. 6 is a state diagram of the system during pressure equalization of the A-B column during nitrogen generation alone in example 2.
FIG. 7 is a diagram showing the state of the system in the adsorption process by column B in the case of producing nitrogen alone in example 2.
FIG. 8 is a state diagram of the system during B-A column equalization in the case of nitrogen production alone in example 2.
FIG. 9 is a state diagram of the system in column C adsorption process for the sole production of oxygen in example 3.
FIG. 10 is a state diagram of the system during C-D column equalization for oxygen production alone in example 3.
FIG. 11 is a state diagram of the system in the D-column adsorption process for the sole oxygen production in example 3.
FIG. 12 is a state diagram of the system during D-C column equalization for oxygen production alone in example 3.
Description of reference numerals: a-a first nitrogen making adsorption separation tank; b-a second nitrogen-making adsorption separation tank; c-a first oxygen-producing adsorptive separation tank; d-a second oxygen-making adsorption separation tank; GY 1-Nitrogen making process tank; GY 2-oxygen generation process storage tank; KV1 ab-raw material air inlet and waste gas evacuation three-position five-way middle seal valve for nitrogen production; KV1 cd-raw material air inlet and waste gas evacuation three-position five-way middle seal valve for oxygen production; KV2 ef-product gas outlet three-position three-way middle valve for nitrogen production; KV2 gh-product gas outlet three-position three-way middle valve for oxygen production; KV3 ij-pressure equalizing three-position three-way middle sealing valve for nitrogen production; KV3 kl-pressure equalizing three-position three-way middle seal valve for oxygen production; g3-pressure equalizing high-pressure selecting valve for nitrogen making; g4-pressure equalizing high-pressure selection valve for oxygen production; d5, D8-pressure equalizing low-pressure selecting valve for nitrogen making; d6, D7-pressure equalizing low-pressure selection valve for oxygen production; c1-flushing needle valve for nitrogen making; c2-flush needle valve for oxygen production.
Detailed Description
The PSA pressure swing adsorption nitrogen and oxygen making integrated system at least comprises two nitrogen making adsorption separation tanks, two oxygen making adsorption separation tanks, a nitrogen making process storage tank GY1, an oxygen making process storage tank GY2, various control valves, connecting pipelines and a program controller, wherein the control valves comprise a raw material air inlet for nitrogen making, a waste gas evacuation three-position five-way middle seal valve KV1ab, a raw material air inlet for oxygen making, a waste gas evacuation three-position five-way middle seal valve KV1cd, a product air outlet three-position three-way middle seal valve KV2ef for nitrogen making, a product air outlet three-position three-way middle seal valve KV2gh for oxygen making, a pressure equalizing three-position three-way middle seal valve KV3ij for nitrogen making, a pressure equalizing three-position three-way middle seal valve KV3kl for oxygen making, a pressure equalizing high selection valve G3 for nitrogen making, a pressure equalizing high selection valve G4 for oxygen making, a pressure equalizing low selection valve D5, D8, a pressure equalizing low selection valve D6, a pressure equalizing selection valve D7, a flushing needle valve C1 for nitrogen making, a flushing needle valve C2 and a, The following loops are formed between the adsorption separation tanks:
a pressure-boosting adsorption loop: the system comprises an input pipeline, and a switching valve nitrogen-making raw material inlet valve, a waste gas evacuation three-position five-way middle sealing valve KV1ab, a raw material inlet valve for oxygen making, a waste gas evacuation three-position five-way middle sealing valve KV1cd, a product gas outlet three-position three-way middle valve KV2ef and a product gas outlet three-position three-way middle sealing valve KV2gh which correspond to a first nitrogen-making adsorption separation tank A, a second nitrogen-making adsorption separation tank B, a first oxygen-making adsorption separation tank C, a second oxygen-making adsorption separation tank D, a nitrogen-making process storage tank GY1 and an oxygen-making process storage tank GY 2;
a pressure equalizing loop: the system comprises an input pipeline, and a pressure equalizing high-selection valve (G3) for nitrogen making, a pressure equalizing high-selection valve G4 for oxygen making, a pressure equalizing three-position three-way middle sealing valve KV3ij for nitrogen making, a pressure equalizing three-position three-way middle sealing valve KV3kl for oxygen making, a pressure equalizing low-selection valve D5 and D6 for nitrogen making, a pressure equalizing low-selection valve D7 and D8 which correspond to a first nitrogen making adsorption separation tank A, a second nitrogen making adsorption separation tank B, a first oxygen making adsorption separation tank C and a second oxygen making adsorption separation tank D.
The raw material air inlet and waste gas exhaust for nitrogen and oxygen production adopt the three-position five-way middle sealing valve KV1ab for nitrogen and waste gas exhaust, the raw material air inlet and waste gas exhaust three-position five-way middle sealing valve KV1cd for oxygen production to control the raw material air inlet and waste gas exhaust through a process controller.
The nitrogen and oxygen production product gas outlet adopts the product gas outlet three-position three-way middle valve KV2ef for nitrogen production, the product gas outlet three-position three-way middle valve KV2gh for oxygen production, and the process controller passes through the nitrogen production process storage tank GY1 and the oxygen production process storage tank GY2 to achieve the output of the nitrogen and oxygen and the pressure equalization on the process.
And the oxygen-enriched waste gas in the first nitrogen-making adsorption separation tank A is subjected to pressure equalization by a pressure equalization high-selection valve G3 for nitrogen making, a pressure equalization three-position three-way middle-sealing valve KV3ij for nitrogen making and a pressure equalization low-selection valve D7 for oxygen making to a first oxygen-making adsorption separation tank C.
And the nitrogen-rich waste gas in the second oxygen production adsorption separation tank D is subjected to pressure equalization by a pressure equalization high-selection valve G4 for oxygen production, a pressure equalization three-position three-way middle-sealing valve KV3kl for oxygen production and a pressure equalization low-selection valve D8 for nitrogen production to perform pressure equalization on the second nitrogen production adsorption separation tank B.
And the oxygen-enriched waste gas in the second nitrogen-making adsorption separation tank B is subjected to pressure equalization by a pressure equalization high-selection valve G3 for nitrogen making, a pressure equalization three-position three-way middle-sealing valve KV3ij for nitrogen making and a pressure equalization low-selection valve D7 for oxygen making to a second oxygen-making adsorption separation tank D.
And the nitrogen-rich waste gas in the first oxygen production adsorption separation tank C is subjected to pressure equalization by a pressure equalization high-selection valve G4 for oxygen production, a pressure equalization three-position three-way middle-sealing valve KV3kl for oxygen production and a pressure equalization low-selection valve D8 for nitrogen production to perform pressure equalization on the first nitrogen production adsorption separation tank A.
Example 1
A method for simultaneously preparing nitrogen and oxygen by a PSA pressure swing adsorption nitrogen and oxygen preparation integrated system comprises the following steps:
(1) the first pressure-boosting adsorption process, as shown in fig. 1:
a. the dry air after being pretreated, deoiled and dewatered enters a first nitrogen-making adsorption separation tank A through a raw material inlet three-position five-way middle seal valve KV1ab for nitrogen making and exhaust gas evacuation to adsorb oxygen, and unadsorbed nitrogen is output into product nitrogen through a product outlet three-position three-way middle seal valve KV2ef and a product nitrogen from a nitrogen-making process storage tank GY 1;
b. the dry air after pretreatment, oil removal and water removal enters a second oxygen production adsorption separation tank D through a raw material inlet three-position five-way middle seal valve KV1cd for oxygen production and exhaust gas evacuation to adsorb nitrogen, and unadsorbed oxygen is output as product oxygen through a product outlet three-position three-way middle seal valve KV2gh and an oxygen production process storage tank GY 2;
c. the residual gas in the second nitrogen-making adsorption separation tank B is directly discharged into the atmosphere through a raw material inlet and waste gas evacuation three-position five-way middle seal valve KV1ab for nitrogen making;
d. the residual gas in the first oxygen-making adsorption separation tank C is directly discharged into the atmosphere through a raw material inlet for oxygen making and a three-position five-way middle seal valve KV1cd for waste gas evacuation;
(2) the first pressure equalizing process is as shown in fig. 2:
a. the first nitrogen making adsorption separation tank A and the second nitrogen making adsorption separation tank B are conducted through a three-position three-way middle-way valve KV2ef for nitrogen making product gas outlet to finish pressure equalizing on nitrogen, and meanwhile, the first oxygen making adsorption separation tank C and the second oxygen making adsorption separation tank D are conducted through a three-position three-way middle-way valve KV2gh for oxygen making product gas outlet to finish pressure equalizing on oxygen;
b. the oxygen-enriched waste gas in the first nitrogen-making adsorption separation tank A is subjected to pressure equalization by a pressure equalization high-selection valve G3 for nitrogen making, a pressure equalization three-position three-way middle sealing valve KV3ij for nitrogen making and a pressure equalization low-selection valve D7 for oxygen making; meanwhile, nitrogen-rich waste gas in the second oxygen production adsorption separation tank D is subjected to pressure equalization by a pressure equalization high-selection valve G4 for oxygen production, a pressure equalization three-position three-way middle-sealing valve KV3kl for oxygen production and a pressure equalization low-selection valve D8 for nitrogen production to perform pressure equalization on the second nitrogen production adsorption separation tank B;
(3) the second pressure-boosting adsorption process, as shown in fig. 3:
a. the dry air after being pretreated, deoiled and dewatered enters a second nitrogen-making adsorption separation tank B through a raw material inlet three-position five-way middle seal valve KV1ab for nitrogen making and waste gas evacuation to adsorb oxygen, and unadsorbed nitrogen is output into product nitrogen through a product outlet three-position three-way middle seal valve KV2ef and a product nitrogen output process storage tank GY1 for nitrogen making;
b. the dry air after pretreatment, oil removal and water removal enters a first oxygen production adsorption separation tank C through a raw material inlet three-position five-way middle seal valve KV1cd for oxygen production and exhaust gas evacuation to adsorb nitrogen, and unadsorbed oxygen is output as product oxygen through a product outlet three-position three-way middle seal valve KV2gh and an oxygen production process storage tank GY 2;
c. the residual air pressure in the first nitrogen-making adsorption separation tank A is directly discharged into the atmosphere through a raw material air inlet and waste gas evacuation three-position five-way middle seal valve KV1ab for nitrogen making;
d. the residual air pressure in the second oxygen-making adsorption separation tank D is directly discharged into the atmosphere through raw material air inlet and waste gas evacuation three-position five-way middle seal valve KV1cd for oxygen making;
(4) and a second pressure equalizing process, as shown in fig. 4:
a. the first nitrogen-making adsorption separation tank A and the second nitrogen-making adsorption separation tank B are conducted through a three-position three-way middle-way valve KV2ef for nitrogen-making product gas outlet to finish nitrogen upper pressure equalizing; the first oxygen-making adsorption separation tank C and the second oxygen-making adsorption separation tank D are conducted through a three-position outlet three-way middle valve KV2gh of an oxygen-making product to finish the pressure equalization on oxygen;
b. the oxygen-enriched waste gas in the second nitrogen-making adsorption separation tank B is subjected to lower pressure equalization on a second oxygen-making adsorption separation tank D through a pressure equalization high-selection valve G3 for nitrogen making, a pressure equalization three-position three-way middle sealing valve KV3ij for nitrogen making and a pressure equalization low-selection valve D7 for oxygen making; meanwhile, nitrogen-rich waste gas in the first oxygen production adsorption separation tank C is subjected to pressure equalization by a pressure equalization high-selection valve G4 for oxygen production, a pressure equalization three-position three-way middle-sealing valve KV3kl for oxygen production and a pressure equalization low-selection valve D8 for nitrogen production to the first nitrogen production adsorption separation tank A.
Example 2
A method for independently producing nitrogen by a PSA pressure swing adsorption nitrogen and oxygen production integrated system is described in detail by taking a first nitrogen production adsorption separation tank A and a second nitrogen production adsorption separation tank B as examples, and comprises the following steps:
(1) the adsorption process of the independent nitrogen preparation A tower: the dry raw material air after being pretreated by air, deoiled and dewatered enters a first nitrogen-making adsorption separation tank A through a raw material air inlet and waste gas evacuation three-position five-way middle seal valve KV1ab to adsorb oxygen, unadsorbed nitrogen enters a nitrogen-making product air outlet three-position three-way middle seal valve KV2ef, the nitrogen-making process storage tank GY1 outputs product nitrogen, and meanwhile, residual gas in a second nitrogen-making adsorption separation tank B is directly exhausted into the atmosphere through a raw material air inlet and waste gas evacuation three-position five-way middle seal valve KV1ab, which is shown in the attached figure 5;
(2) the pressure equalizing process of the independent nitrogen preparation A-B tower is as follows: the first nitrogen-making adsorption separation tank A and the second nitrogen-making adsorption separation tank B are conducted through a nitrogen-making product gas outlet three-position three-way middle-way valve KV2ef to finish the pressure equalization of nitrogen gas, and oxygen-enriched waste gas in the first nitrogen-making adsorption separation tank A is subjected to pressure equalization on the second nitrogen-making adsorption separation tank B through a nitrogen-making pressure equalization high-selection valve G3, a nitrogen-making pressure equalization three-position three-way middle-sealing valve (KV 3 ij) and a nitrogen-making pressure equalization low-selection valve D5, which are shown in the attached figure 6;
(3) the adsorption process of the independent nitrogen preparation B tower comprises the following steps: when the pressure equalizing process is finished, the pressure in the second nitrogen-making adsorption separation tank B is only half of the working pressure, and in order to enable the second nitrogen-making adsorption separation tank B to enter a new working cycle as soon as possible, the pressure is finally increased by utilizing dry raw material air; namely, dry raw material air enters a second nitrogen making adsorption separation tank B to adsorb oxygen through a raw material air inlet and waste gas evacuation three-position five-way middle seal valve KV1ab for nitrogen making, unadsorbed nitrogen enters a nitrogen making product air outlet three-position three-way middle seal valve KV2ef, the nitrogen making process storage tank GY1 outputs product nitrogen, meanwhile, residual air pressure in a first nitrogen making adsorption separation tank A is directly discharged into the atmosphere through a raw material air inlet and waste gas evacuation three-position five-way middle seal valve KV1ab for nitrogen making, residual air pressure in an oxygen making adsorption separation tank D is directly discharged into the atmosphere through a raw material air inlet and waste gas evacuation three-position five-way middle seal valve KV1cd for oxygen making, and the process is shown in figure 7;
(4) the pressure equalizing process of the independent nitrogen preparation B-A tower is as follows: the second nitrogen making adsorption separation tank B and the first nitrogen making adsorption separation tank A are conducted through a product gas outlet three-position three-way middle-way valve KV2ef for nitrogen making, the upper pressure equalizing of nitrogen is completed, oxygen-enriched waste gas in the second nitrogen making adsorption separation tank B is subjected to lower pressure equalizing through a pressure equalizing high-selection valve G3 for nitrogen making, a pressure equalizing three-position three-way middle-sealing valve KV3ij for nitrogen making and a pressure equalizing low-selection valve D5 for nitrogen making, and the attached drawing 8 shows that the first nitrogen making adsorption separation tank A is subjected to pressure equalizing.
Example 3
A method for independently producing oxygen by a PSA pressure swing adsorption nitrogen and oxygen production integrated system is described in detail by taking a first oxygen production adsorption separation tank C and a second oxygen production adsorption separation tank D as examples, and comprises the following steps:
(1) the adsorption process of the independent oxygen production C tower comprises the following steps: the dry raw material air after the air pretreatment, oil removal and water removal enters a first oxygen production adsorption separation tank C through a raw material air inlet for oxygen production and a waste gas evacuation three-position five-way middle seal valve KV1cd to adsorb nitrogen, unadsorbed oxygen is output as product oxygen from an oxygen production process storage tank GY 39GY 2 through a product air outlet three-position three-way middle valve KV2gh, and meanwhile, residual gas in a second oxygen production adsorption separation tank D is directly exhausted into the atmosphere through a raw material air inlet for oxygen production and a waste gas evacuation three-position five-way middle seal valve KV1cd, which is shown in the attached figure 9;
(2) the pressure equalizing process of the independent oxygen generation C-D tower is as follows: the first oxygen-making adsorption separation tank C and the second oxygen-making adsorption separation tank D are conducted through a three-position three-way middle valve KV2gh for oxygen-making product gas outlet, oxygen upper pressure equalizing is completed, and meanwhile, nitrogen-rich waste gas in the first oxygen-making adsorption separation tank C is subjected to lower pressure equalizing on the second oxygen-making adsorption separation tank D through a pressure equalizing high-selection valve G4 for oxygen making, a pressure equalizing three-position three-way middle-sealing valve KV3kl for oxygen making and a pressure equalizing low-selection valve D6 for oxygen making, which are shown in the attached drawing 10;
(3) adsorption process of the separate oxygen production D tower: when the pressure equalizing process is finished, the pressure in the second oxygen generation adsorption separation tank D is only half of the working pressure, and in order to enable the second oxygen generation adsorption separation tank D to enter a new working cycle as soon as possible, the pressure is finally increased by utilizing dry raw material air; namely, dry raw material air enters a second oxygen-making adsorption separation tank D to adsorb nitrogen through a raw material air inlet and waste gas evacuation three-position five-way middle seal valve KV1cd for oxygen making, unadsorbed oxygen passes through a product air outlet three-position three-way middle seal valve KV2gh for oxygen making, the product oxygen is output by an oxygen making process storage tank GY2, and meanwhile, residual air pressure in the first oxygen-making adsorption separation tank C is directly discharged into the atmosphere through the raw material air inlet and waste gas evacuation three-position five-way middle seal valve KV1cd for oxygen making, which is shown in the attached figure 11;
(4) pressure equalizing process of independent oxygen generation D-C tower: the second system oxygen adsorption separation jar D and the first system oxygen adsorption separation jar C are led on by the product three-position tee bend meson valve KV2gh that gives vent to anger for the system oxygen, accomplish the pressure-sharing on the oxygen, simultaneously, the rich nitrogen waste gas in the second system oxygen adsorption separation jar D is through the pressure-sharing high-selection valve G4 for the system oxygen, seal valve KV3kl in the pressure-sharing three-position tee bend for the system oxygen and the pressure-sharing low-selection valve D6 for the system oxygen carries out pressure-sharing down to first system oxygen adsorption separation jar C, see figure 12.
The foregoing is illustrative of the preferred embodiments of the present invention only and is not to be construed as limiting the claims. Various modifications or additions may be made to the described embodiments or alternatives may be employed by those skilled in the art without departing from the spirit or ambit of the invention as defined in the appended claims.