WO2022068165A1

WO2022068165A1 - Efficient vpsa oxygen production process and system thereof

Info

Publication number: WO2022068165A1
Application number: PCT/CN2021/085289
Authority: WO
Inventors: 李祎; 杨波
Original assignee: 成都华西堂投资有限公司
Priority date: 2020-09-29
Filing date: 2021-04-02
Publication date: 2022-04-07
Also published as: CN112079334A; CN112079334B

Abstract

Provided is an efficient VPSA oxygen production process, comprising a pressure equalizing tank (V3), a blower (C), a vacuum pump (P), an oxygen enrichment tank (V4) and at least three adsorption towers (T1, T2, T3); the oxygen production cycle of a single adsorption tower comprises: adsorption, release and pressure equalization, vacuum desorption, and pressure equalization and pressure boosting; and the adsorption time in the oxygen production cycle is longer than the vacuumization desorption time, all of the adsorption towers communicate in order with the pressure equalizing tank for release and pressure equalization or pressure equalization and pressure boosting, and the conversion of the adsorption towers from adsorption to desorption and the conversion of the adsorption towers from desorption to adsorption are achieved. The process increases the proportion of adsorption time, enables an adsorbent to be fully utilized, and thus significantly improves work efficiency and the utilization rate of the adsorbent.

Description

An efficient VPSA oxygen production process and its system

technical field

The invention relates to the technical field of industrial oxygen production, in particular to an efficient VPSA oxygen production process.

Background technique

PSA oxygen enrichment has the advantages of low investment, low energy consumption, simple equipment and flexible operation, especially in the small and medium-scale oxygen production process, which greatly reduces the production energy consumption, and is widely used in chemical industry, medicine and environmental protection (waste incineration). , industrial oxygen-enriched combustion and wastewater treatment, etc.). Among them, the vacuum pressure swing adsorption process (VPSA) uses the vacuum method to regenerate the adsorbent, and the regeneration effect is good, and at the same time, the amount of flushing gas is effectively reduced, and the energy consumption is reduced.

The VPSA process uses air as the raw material. In the adsorber, the moisture, carbon dioxide and nitrogen components in the air are adsorbed by the molecular sieve in the lower part, and the unadsorbed oxygen is enriched at the top of the adsorption tower as the product gas output. The pressure equalization operation of the existing adsorption tower is carried out through the pressure equalization valve at the top of the tower. During this period, the adsorption tower cannot produce oxygen and the utilization rate is low. Therefore, two adsorption towers are usually set up. When the oxygen is released, the other adsorption tower is in the state of vacuum regeneration. The two adsorption towers alternately repeat oxygen production and regeneration to achieve continuous oxygen extraction. The work efficiency is often not high, and the utilization rate of the adsorbent is only 40%.

Invention patent CN106698357A discloses a three-tower low-pressure adsorption vacuum desorption method for preparing oxygen. The device includes a blower, a vacuum pump, a first adsorption tower, a second adsorption tower, a third adsorption tower, a first pressure equalizing tank, and a second equalizing tank. and oxygen buffer tank. In this method, the utilization rate of oxygen is improved by adding a first pressure equalizing tank and a second pressure equalizing tank to collect oxygen-depleted gas, but at the same time only one tower is adsorbing, one tower is pressure equalizing, and one tower is evacuating, that is, one adsorption cycle Only 1/3 of the time is adsorbed, and the adsorption efficiency is low.

SUMMARY OF THE INVENTION

In view of the above technical problems, the present invention provides an efficient VPSA oxygen production process. This process increases the proportion of the adsorption time, makes the adsorbent fully utilized, and significantly improves the work efficiency and the utilization rate of the adsorbent.

In order to realize the purpose of the invention, the technical scheme adopted in the present invention is:

An efficient VPSA oxygen production process, including pressure equalizing tank, blower, vacuum pump, oxygen enrichment tank and at least 3 adsorption towers; the oxygen production cycle of a single adsorption tower includes:

A. Adsorption: The air blower sends the air into the adsorption tower to produce oxygen and sends it to the oxygen-enriched tank;

B. Smooth release and pressure equalization: After the adsorption tower completes the adsorption, the inlet and outlet valves are closed to stop supplying oxygen, and the gas in the tower is put into the pressure equalizing tank to balance the air pressure in the tower and the pressure equalizing tank;

C. Vacuum analysis: use a vacuum pump to vacuum the adsorption tower to regenerate the adsorbent;

D. Equalizing and boosting: use the gas in the equalizing tank to inflate the adsorption tower and equalize the pressure, so that the air pressure in the tower and the equalizing tank are balanced;

The adsorption time in the oxygen production cycle is longer than the vacuum desorption time, the adsorption time in the oxygen production cycle is longer than the vacuum desorption time, and all the adsorption towers are connected to the pressure equalizing tank in sequence, and the pressure is equalized or communicated with each other. The pressure is equalized and boosted to realize the conversion of the adsorption tower from adsorption to desorption and the conversion of the adsorption tower from desorption to adsorption.

The VPSA oxygen production process of the present invention has no less than two adsorption towers in the adsorption state at the same time.

Preferably, if there are 3 adsorption towers, two towers are adsorbed and one tower is regenerated at the same time; if there are 4 adsorption towers, three adsorption towers are regenerated at the same time, and one tower is regenerated; if there are 5 adsorption towers, three adsorption towers are regenerated at the same time. ; If there are 6 adsorption towers, at the same time four adsorption towers and two towers are regenerated.

The number of adsorption towers in the present invention is n, and the steps of the oxygen production cycle are sequentially divided into 2n stages at the same time: D+A, (A) _2x , A+B, (C) _2y ;

Among them, (A) _2x refers to 2x stages, each stage is A step; (C) _2y refers to 2y stages, each stage is C step, and x+y=n-1, x≠0, y ≠0,x≥y;

D+A means D step plus A step, which is the first stage; A+B means A step plus B step, which is the 2x+2 stage.

All adsorption towers are divided and rolled according to this stage to carry out the oxygen production cycle, and in the same time period, the pressure equalization tank only operates to equalize the pressure of one adsorption tower, and performs pressure equalization and pressure equalization for each tower in sequence. .

The volume of the pressure equalizing tank in the present invention is not less than the volume of the adsorption tower, so that the pressure of the pressure equalizing tank after the pressure equalization is close to the atmospheric pressure, forming a necessary pressure difference with the adsorption tower in the pressure equalizing and boosting operation, so as to increase the pressure in the pressure equalizing operation. During the pressure process, the pressure equalization and pressure increase operation of the adsorption tower is quickly completed. Recover the oxygen in the dead space of the adsorption tower after the adsorption is completed, and improve the oxygen yield of the device.

Preferably, the time for equalizing the pressure and increasing the pressure each time is 1-5s. Shorten the time of pressure equalization, increase the proportion of adsorption time, and easily adjust the proportion of adsorption and vacuum time, and realize alternate adsorption and regeneration of multiple towers.

Further preferably, the air pressure of the pressure equalizing tank is maintained between -5kPa～+5kPa. The air pressure of the conventional adsorption tower after adsorption is about 50kPa, and the air pressure after vacuuming is about -50kPa. It can form an ideal pressure difference with the adsorption tower and quickly equalize the pressure.

The present invention also provides a system for the high-efficiency VPSA oxygen production process, including a blower, a vacuum pump, an oxygen-enriched tank, a pressure equalizing tank, and an adsorption tower group formed by paralleling at least three adsorption towers. The blower, the oxygen-enriched tank and the vacuum pump Each adsorption tower is respectively connected, the pressure equalizing tank and each adsorption tower form a passage that can be switched on and off, and a program-controlled valve is arranged on the connecting pipeline between each equipment.

Preferably, the blower is provided with an air buffer tank on the connecting pipeline with the adsorption tower group, and the vacuum pump is provided with a vacuum buffer tank on the connecting pipeline with the adsorption tower group.

During the vacuuming process of the adsorption tower, the air pressure of the vacuum buffer tank is the same as that of the adsorption tower. When the air pressure of the adsorption tower reaches the analytical negative pressure of about -50kPa, it switches to the next adsorption tower for vacuuming. At this time, the adsorption tower is under pressure equalization. In the process of boosting pressure for 1 to 5s, the vacuum valve of the adsorption tower has not been opened during this process, and the vacuum pump will vacuum the vacuum buffer tank, which not only saves the energy consumed by the vacuum pump but also reduces the pressure fluctuation of the vacuum pump, which provides better protection. equipment.

Put the air from the blower outlet into the air buffer tank for energy storage. During the adsorption process of the blower, the air pressure of the air buffer tank is the same as that of the adsorption tower. When the air pressure of the adsorption tower reaches about 50kPa, it switches to the next adsorption tower. At this time, the adsorption tower is in the process of equalizing and boosting for 1 to 5 seconds. The intake valve of the adsorption tower has not been opened, and the air from the blower is poured into the buffer tank, which not only avoids the blockage of the blower, but also reserves the blower. consumption and energy.

Preferably, the air inlet of the blower is provided with a filter, and the air outlet of the blower is provided with a heat exchanger. The air entering the adsorption tower is first filtered, and the clean air is used as the raw material to enter the blower. After boosting, the air is cooled by the heat exchanger, so that the temperature is lowered to the optimum adsorption performance temperature of the molecular sieve, and then enters the adsorption that has been regenerated and is in a working state. tower.

Preferably, the air inlet of the vacuum pump is provided with a filter to filter out part of the adsorbent dust carried by the air after entering the adsorption tower, and discharge clean nitrogen into the atmosphere.

The beneficial effects of the present invention are:

1. The present invention adopts the pressure equalizing tank to complete the smooth release and pressure equalizing and pressure increasing operation of the adsorption tower, so that the pressure in the tower after the equalization is balanced with the pressure equalizing tank, and the pressure of the adsorption tower of about plus or minus 50kpa can be adjusted within a few seconds. The internal pressure is quickly equalized to close to the atmospheric pressure of the air, the rapid pressure equalization is performed before adsorption, and the rapid punching is performed after the adsorption to improve the pressure equalization and punching efficiency of the device. Compared with the traditional pressure equalization method, the pressure equalization time in the oxygen production cycle is saved. , increasing the proportion of adsorption time, so that the adsorbent is fully utilized, and the oxygen in the dead space of the adsorption tower is effectively recovered.

2. The present invention divides the steps of the oxygen production cycle into 2n stages of the same time in sequence. Since the pressure equalization time is only a few seconds, the pressure equalization and the adsorption operation are classified into the same stage, and the adsorption tower is divided and rolled according to this stage. Oxygen cycle is cycled, and the pressure equalizing tank alternately discharges and equalizes pressure and equalizes pressure for each tower. After the distribution according to this method, the oxygen production system can always be in multiple towers for simultaneous adsorption, and the towers in the adsorption state are more than the towers that are evacuated and the program waits, which effectively improves the utilization efficiency of molecular sieves. For example, the three-tower process has always had two Each tower is evacuated in one tower, and the adsorption time of each adsorption tower is longer than the time of vacuuming, and the utilization rate of molecular sieve is as high as 66%.

3. Increase the air buffer tank and the vacuum buffer tank. When the adsorption tower is evacuated, first equalize the pressure with the vacuum buffer tank, so that the initial pressure of the vacuum pump is the pressure after the pressure equalization, instead of starting from the atmospheric pressure, let the adsorption The tower pressure reaches the negative pressure in a very short time, which reduces the pressure fluctuation at the inlet of the vacuum pump and better protects the equipment.

4. After the initial pressure equalization of the adsorption tower and the pressure equalizing tank, the pressure is further equalized by the air buffer tank or the vacuum buffer tank, which further accelerates the pressure equalization time, and avoids the direct pressure equalization with the air buffer tank or the vacuum buffer tank. The pressure fluctuations of other adsorption towers can be reduced, so that the pressure fluctuations of the operating system are smaller and the stability is higher.

Description of drawings

Fig. 1 is the 3 tower structure schematic diagram of the VPSA oxygen production system of the present invention.

Figure 2 is a schematic diagram of the 4-column structure of the VPSA oxygen production system of the present invention.

Figure 3 is a schematic diagram of the 5-column structure of the VPSA oxygen production system of the present invention.

Figure 4 is a schematic diagram of the structure of the 6 towers of the VPSA oxygen production system of the present invention.

Detailed ways

In order to illustrate the technical solutions of the present invention more clearly and in detail, the present invention will be further described below through relevant embodiments. The following examples are only to specifically illustrate the implementation method of the present invention, and do not limit the protection scope of the present invention.

Example 1

An efficient VPSA oxygen production process, including pressure equalization tank, blower, vacuum pump, oxygen enrichment tank and at least 3 adsorption towers; the oxygen production cycle of a single adsorption tower includes:

B. Smooth release and pressure equalization: after the adsorption tower completes adsorption, stop sending oxygen, and put the remaining gas in the tower into the pressure equalizing tank to balance the pressure in the tower and the pressure equalizing tank;

The adsorption time in the oxygen production cycle is longer than the vacuum desorption time, and all the adsorption towers are connected with the pressure equalizing tank in order to release the pressure or to increase the pressure to realize the conversion from adsorption to desorption of adsorption towers. The conversion of the adsorption column from desorption to adsorption.

Example 2

This embodiment is on the basis of Embodiment 1:

The volume of the pressure equalizing tank is not less than the volume of the adsorption tower, so that the pressure of the pressure equalizing tank after pressure equalization is close to atmospheric pressure, and a large pressure difference is formed with the adsorption tower in the next pressure equalizing operation, so that the adsorption can be quickly absorbed within 1-5s. The tower completes the pressure equalization operation.

Calculated according to the volume of the pressure equalizing tank is twice the adsorption tower (the volume of the pressure equalizing tank can be increased according to the needs of the project):

The first cycle: the pressure of the adsorption tower 50kPa and the pressure equalization tank 0kPa after the pressure equalization is +17kPa, the pressure after the adsorption tower -50kPa and the pressure equalization tank +17kPa equalization and boosting is -22kPa;

The second cycle: the pressure of the adsorption tower 50kPa and the pressure equalization tank -22kPa after the pressure equalization is +2kPa, the pressure after the adsorption tower -50kPa and the pressure equalization tank +2kPa equalization and boosting is -17kPa;

The third cycle: the pressure of the adsorption tower 50kPa and the pressure equalization tank -17kPa after the pressure equalization is +5kPa, and the pressure after the adsorption tower -50kPa and the pressure equalization tank +5kPa equalization and boosting is -13kPa;

The 4th cycle: the pressure after adsorption tower 50kPa and pressure equalizing tank-13kPa equalizing pressure is +8kPa, and the pressure after adsorption tower-50kPa and pressure equalizing tank+8kPa equalizing pressure boosting is-11kPa;

The pressure of the pressure equalizing tank is gradually stabilized in a certain positive and negative range with the continuous repetition of the oxygen production cycle, and is close to the atmospheric pressure. .

Example 3

This embodiment is on the basis of Embodiment 1:

The volume of the pressure equalizing tank is equal to the volume of the adsorption tower, and the time for each time of pressure equalization and pressure equalization is 5s.

Example 4

This embodiment is on the basis of Embodiment 1:

The air pressure of the pressure equalizing tank is maintained between -15kPa～+15kPa. The air pressure of the conventional adsorption tower after adsorption is about 50kPa, and the air pressure after vacuuming is about -50kPa. It can form an ideal pressure difference with the adsorption tower and quickly equalize the pressure.

Example 5

This embodiment is on the basis of Embodiment 1:

The volume of the pressure equalizing tank is 3 times the volume of the adsorption tower, and the time for each time of pressure equalization and pressure equalization and pressure increase is 1s.

Example 6

This embodiment is on the basis of Embodiment 1:

The number of the adsorption towers is n, and the steps of the oxygen production cycle are sequentially divided into 2n stages at the same time: D+A, (A) _2x , A+B, (C) _2y ;

Among them, (A) _2x refers to 2x stages, each stage is A step; (C) _2y refers to 2y stages, each stage is C step, and x+y=n-1, x≠0, y ≠0, x≥y;

All adsorption towers are divided and rolled according to this stage to carry out the oxygen production cycle, and in the same time period, the pressure equalizing tank only operates to equalize the pressure of one adsorption tower, and alternately performs equalization and pressure equalization for each tower.

D+A refers to the pressure equalization and then the adsorption, A+B refers to the first adsorption and then the pressure equalization; since the pressure equalization time is only a few seconds, the pressure equalization and the adsorption operation are classified into the same stage, and the adsorption time can be timely according to the oxygen purity requirements. adjust.

According to this formula, the oxygen production cycle is divided into isochronous stages, and then the flow of each adsorption tower is sorted according to the pressure equalization requirements, and an efficient oxygen production process can be realized.

D+A means D steps plus A steps, which is the first stage; A+B means A steps plus B steps, which is the 2x+2 stage.

Example 7

Three-tower process system

As shown in Figure 1, the equipment is composed of blower (C), vacuum pump (P), adsorption tower (T1-T3), air buffer tank (V1), vacuum buffer tank (V2), pressure equalizing tank (V3), rich Oxygen tank (V4), filter U1, filter U2, heat exchanger (E), program-controlled valve group (A1~A5).

The cycle operation process of a single adsorption tower:

(1) Oxygen production by adsorption

a. Equalizing and boosting: open the program-controlled valve A4, close A1, A2, A3, and A5, and put the pressure of the equalizing tank into the adsorption tower to increase the pressure of the adsorption tower.

b. Adsorption: Open the program-controlled valves A1, A2, close A3, A4, and A5, and cool the air to about 40 degrees through the heat exchanger and send it to the adsorption tower for adsorption and separation to produce oxygen, and the enriched oxygen enters the oxygen storage tank from the top of the tower ( V4), adjust the oxygen pressure by adjusting the outlet of the oxygen storage tank (V4) and send the enriched oxygen to the oxygen-consuming section.

c. Smooth discharge and pressure equalization: Open the program-controlled valve A3, close A1, A2, A4, and A5, put the pressure of the adsorption tower into the pressure equalization tank (V3), and depressurize the adsorption tower (the time can be set according to the actual depressurization).

(2) Regeneration of adsorbent

Close A1, A2, A3, A4, open A5 to start vacuuming, and discharge the nitrogen adsorbed by the adsorbent to the atmosphere to regenerate the adsorbent.

Oxygen production process control of three adsorption towers:

Table 1 Three-tower program-controlled time allocation table

By opening and closing each program-controlled valve, the process control in Table 1 is realized. In the oxygen production process of the three-tower system, two adsorption towers are adsorbing at the same time in each time period, and one adsorption tower is vacuuming; the pressure equalizing tank alternately boosts and discharges the pressure for each adsorption tower one by one during the whole process. . The adsorbent utilization rate is as high as 66%.

Example 8

Four-tower process system

As shown in Figure 2, the equipment is composed of blower (C), vacuum pump (P), adsorption tower (T1-T4), air buffer tank (V1), vacuum buffer tank (V2), pressure equalizing tank (V3), rich Oxygen tank (V4), filter U1, filter U2, heat exchanger (E), program-controlled valve group (A1~A5).

Oxygen production process control of four adsorption towers:

Table 2 Four-tower program-controlled time allocation table

By opening and closing each program-controlled valve, the process control in Table 2 is realized. In the oxygen production process of the four-column system, three adsorption towers are simultaneously adsorbing in each time period, and one adsorption tower is vacuuming; the pressure equalizing tank alternately boosts and equalizes pressure for each adsorption tower one by one during the whole process. The adsorbent utilization rate is as high as 75%.

Example 9

Five-tower process system

As shown in Figure 3, the equipment is composed of blower (C), vacuum pump (P), adsorption tower (T1-T5), air buffer tank (V1), vacuum buffer tank (V2), pressure equalizing tank (V3), rich Oxygen tank (V4), filter U1, filter U2, heat exchanger (E), program-controlled valve group (A1~A5).

Oxygen production process control of five adsorption towers:

Table 3 Five-tower program-controlled time allocation table

By opening and closing each program-controlled valve, the flow control in Table 3 is realized. In the oxygen production process of the five-column system, three adsorption towers are adsorbing at the same time in each time period, and two adsorption towers are vacuuming; the pressure equalizing tank alternately boosts and discharges pressure for each adsorption tower one by one during the whole process. . The sorbent utilization rate is as high as 60%.

Example 10

Six tower process system

As shown in Figure 4, the device is composed of: blower (C), vacuum pump (P), adsorption tower (T1-T6), air buffer tank (V1), vacuum buffer tank (V2), pressure equalizing tank (V3), rich Oxygen tank (V4), filter U1, filter U2, heat exchanger (E), program-controlled valve group (A1~A5).

Oxygen production process control of six adsorption towers:

Table 4 Program-controlled time allocation table for six towers

By opening and closing each program-controlled valve, the process control in Table 4 is realized. In the oxygen production process of the six-column system, four adsorption towers are adsorbing at the same time in each time period, and two adsorption towers are vacuuming; the pressure equalizing tank alternately boosts and equalizes pressure for each adsorption tower one by one during the whole process. operate. The adsorbent utilization rate is as high as 66%.

Example 11

As shown in Figure 1-4, the oxygen production system based on the high-efficiency VPSA oxygen production process includes a blower, a vacuum pump, an oxygen-enriched tank, a pressure equalizing tank and an adsorption tower group formed by at least three adsorption towers in parallel. , oxygen enrichment tank and vacuum pump are respectively connected to each adsorption tower, the pressure equalization tank and each adsorption tower form a circulation passage, and the connection pipes between each equipment are provided with program-controlled valves.

Example 12

This embodiment is based on Embodiment 11:

The blower is provided with an air buffer tank on the connection pipeline with the adsorption tower group, and the vacuum pump is provided with a vacuum buffer tank on the connection pipeline with the adsorption tower group.

The air pressure of the air buffer tank during adsorption is equivalent to the pressure value of the blower, and the air pressure of the vacuum buffer tank during vacuuming is equivalent to the pressure value of the vacuum pump.

During the vacuuming process of the adsorption tower, the air pressure of the vacuum buffer tank is the same as that of the adsorption tower. When the air pressure of the adsorption tower reaches about -50kPa, it switches to the next adsorption tower to start vacuuming. The adsorption tower is equalized with the pressure equalizing tank. Then, it is further equalized with the vacuum buffer tank, so that the initial pressure of the vacuum pump is the pressure after the pressure equalization, instead of starting from the atmospheric pressure, so that the pressure of the adsorption tower reaches the negative pressure in a very short time, which reduces the pressure at the inlet of the vacuum pump. Fluctuations, better protection of the equipment.

Example 13

This embodiment is based on Embodiment 11:

The air inlet of the blower is provided with a filter, and the air outlet of the blower is provided with a heat exchanger. The air entering the adsorption tower is first filtered, and the clean air is used as the raw material to enter the blower. After the pressure is increased, it is cooled by the heat exchanger, so that the temperature is lowered to the optimum adsorption performance temperature of the molecular sieve, and then enters the adsorption that has been regenerated and is in a working state. tower.

The air inlet of the vacuum pump is provided with a filter.

When the system has two or more towers for vacuuming at the same time, two or more vacuum pumps can be set up to ensure the independent operation of each vacuuming tower without interfering with each other.

The blower adopted by the utility model can be a Roots blower, a centrifugal blower or a water ring blower; the heat exchanger is a water-cooled air cooler, the filter is a self-cleaning air filter, and the program-controlled valve model is a pneumatic/hydraulic butterfly valve. The specific specifications and models are selected by the size of the device and user needs.

The above-mentioned embodiments only represent specific embodiments of the present invention, and the descriptions thereof are specific and detailed, but should not be construed as limiting the patent scope of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can also be made, which all belong to the protection scope of the present invention.

Claims

An efficient VPSA oxygen production process is characterized in that, comprising a pressure equalizing tank, a blower, a vacuum pump, an oxygen enrichment tank and at least 3 adsorption towers; the oxygen production cycle of a single adsorption tower includes:

A. Adsorption: The air blower sends the air into the adsorption tower to produce oxygen and sends it to the oxygen-enriched tank;

B. Smooth release and pressure equalization: After the adsorption tower completes the adsorption, stop sending oxygen, and put the remaining gas in the tower into the pressure equalizing tank to balance the pressure in the tower and the pressure equalizing tank;

C. Vacuum analysis: use a vacuum pump to vacuum the adsorption tower to regenerate the adsorbent;

D. Equalizing and boosting: using the gas in the equalizing tank to pressurize the adsorption tower, so that the air pressure in the tower and the pressure in the equalizing tank are balanced;

The adsorption time in the oxygen production cycle is longer than the vacuum desorption time, and all the adsorption towers are connected with the pressure equalizing tank in order to release the pressure or to increase the pressure to realize the conversion from adsorption to desorption of adsorption towers. The conversion of the adsorption column from desorption to adsorption.
The high-efficiency VPSA oxygen production process according to claim 1 is characterized in that there are no less than two adsorption towers in an adsorption state at the same time.
The high-efficiency VPSA oxygen production process according to claim 2 is characterized in that, if the number of adsorption towers is 3, two towers are adsorbed and one tower is regenerated at the same time; if there are 4 adsorption towers, three towers are adsorbed and one tower is regenerated at the same time; If the number of adsorption towers is 5, the three adsorption towers will be regenerated at the same time; if the number of adsorption towers is 6, the four adsorption towers will be regenerated at the same time.
The efficient VPSA oxygen production process according to claim 1, wherein the number of adsorption towers is n, and the steps of the oxygen production cycle are sequentially divided into 2n stages at the same time: D+A, (A) ) 2x , A+B, (C) 2y ;

Among them, (A) 2x refers to 2x stages, each stage is A step; (C) 2y refers to 2y stages, each stage is C step, and x+y=n-1, x≠0, y ≠0,x≥y;

All adsorption towers are divided and rolled according to this stage to carry out the oxygen production cycle, and in the same time period, the pressure equalizing tank only performs pressure equalization operation on one adsorption tower, and alternately performs pressure equalization and pressure equalization for each tower.
The efficient VPSA oxygen production process according to claim 1, wherein the volume of the pressure equalizing tank is not less than the volume of the adsorption tower.
The high-efficiency VPSA oxygen production process according to claim 5, characterized in that, the time for equalizing the pressure and increasing the pressure each time is 1-5s.
The system of efficient VPSA oxygen production process according to claim 1, is characterized in that, comprises the adsorption tower group formed by blower, vacuum pump, oxygen-enriched tank, pressure equalizing tank and at least 3 adsorption towers in parallel, The oxygen tank and the vacuum pump are respectively connected to each adsorption tower, the pressure equalization tank and each adsorption tower form a circulation passage, and a program-controlled valve is arranged on the connecting pipeline between each equipment.
The high-efficiency VPSA oxygen production process system according to claim 7, characterized in that, an air buffer tank is provided on the connecting pipeline of the blower with the adsorption tower group, and the vacuum pump is connected with the adsorption tower group. A vacuum buffer tank is arranged on the connecting pipeline.
The high-efficiency VPSA oxygen production process system according to claim 7, wherein the air inlet of the blower is provided with a filter, and the air outlet of the blower is provided with a heat exchanger.
The high-efficiency VPSA oxygen production process system according to claim 7, wherein a filter is provided at the air inlet of the vacuum pump.