Flow control device for improving oxygen concentration of PSA oxygen generator under low flow condition

Abstract

The invention discloses a flow control device for improving the oxygen concentration of a PSA oxygen generator under the low flow condition. The flow control device comprises a compressor, a diverter valve, an oxygen tank and a standby molecular sieve tank and a usable molecular sieve tank, an oxygen inlet, a first outlet and a second outlet are formed in a valve body of the flow dividing valve, a valve assembly is arranged on the valve body, and the valve assembly can adjust the gas path sectional area of a first gas path and the gas path sectional area of a second gas path. An outlet of the compressor is connected with an inlet of the molecular sieve tank, an outlet of the molecular sieve tank is connected with an inlet of the oxygen tank, an outlet of the oxygen tank is connected with an inlet of the diverter valve, and the first outlet is connected with the downstream assembly. By arranging the flow divider valve, the flow of oxygen discharged from the molecular sieve tank is not limited, flow division operation is carried out, redundant oxygen is discharged or recycled, gas output is not limited, the oxygen generator is made to run within the working flow range with the highest oxygen concentration all the time, the nitrogen breakdown effect is avoided, and the service life of the oxygen generator is prolonged. And it is ensured that the oxygen concentration can meet the use requirement under the low-flow condition.

Description

Technical Field

[0001] This invention relates to the field of oxygen production technology, and in particular to a flow control device for improving the oxygen concentration of a PSA oxygen generator under low flow conditions. Background Technology

[0002] Traditional flow valves limit gas flow by controlling the cross-sectional area of ​​the gas path; the smaller the cross-sectional area, the smaller the flow rate. However, the parameters of each gas path in a Pressure Swing Adsorption (PSA) oxygen concentrator are typically configured and adjusted according to the machine's maximum flow rate setting. Artificially reducing the flow rate will prevent the oxygen produced inside the concentrator from being discharged in time, causing it to accumulate at the bottom of the molecular sieve tank. This occupies space in the molecular sieve's adsorption channels, thus limiting the molecular sieve's ability to adsorb nitrogen and reducing the concentration of oxygen produced. This phenomenon is also known as "nitrogen breakdown."

[0003] Therefore, for oxygen concentrators using traditional flow valves, within the rated flow range, the lower the flow rate, the lower the oxygen concentration. This often results in the oxygen concentration at low flow rates failing to meet usage requirements. Summary of the Invention

[0004] This invention provides a flow control device for improving oxygen concentration in a PSA oxygen generator under low flow conditions, thereby overcoming the aforementioned technical problems.

[0005] To achieve the above objectives, the technical solution of the present invention is as follows: A flow control device for improving oxygen concentration in a PSA oxygen generator under low flow conditions includes: a compressor, a flow divider valve, an oxygen tank, and a spare molecular sieve tank. The valve body of the diversion valve is provided with an oxygen inlet, a first outlet and a second outlet. The valve body is provided with a valve assembly, which includes a valve plate. The valve plate divides the interior of the valve body into a first gas path for connecting the oxygen inlet and the first outlet and a second gas path for connecting the oxygen inlet and the second outlet. The valve assembly can adjust the cross-sectional area of ​​the first gas path and the second gas path. The compressor outlet is connected to the inlet of the molecular sieve tank, the molecular sieve tank outlet is connected to the inlet of the oxygen tank, the oxygen tank outlet is connected to the inlet of the diverter valve, and the first outlet is connected to the downstream component.

[0006] Furthermore, the valve assembly also includes a fixed baffle fixed to the valve body, the fixed baffle and the valve plate dividing the interior of the valve body into a first air passage and a second air passage; The fixed baffle is provided with a limiting protrusion, which forms a limiting groove with the inner wall of the valve body. The valve plate is provided with a rotating shaft and a stop block. The valve plate is rotatably mounted on the fixed baffle via the rotating shaft, and the stop block can slide within the limiting groove.

[0007] Furthermore, the valve assembly also includes a motor, which is located on the outside of the valve body, and the output shaft of the motor is used to drive the valve plate to rotate; or, the valve assembly also includes a knob, which can drive the valve plate to rotate.

[0008] Furthermore, the compressor has a filter at its inlet and a cooler at its outlet.

[0009] Furthermore, it also includes a two-position four-way solenoid valve, the four ports of which are respectively connected to the outlet of the compressor, the nitrogen silencer, and the inlets of the two molecular sieve tanks.

[0010] Furthermore, the molecular sieve tank is provided with a throttling orifice at its outlet.

[0011] Furthermore, a pressure reducing valve is provided at the outlet of the oxygen cylinder.

[0012] Furthermore, the second outlet is connected to the atmosphere; or, the second outlet is connected to the compressor inlet.

[0013] Furthermore, a check valve is provided on the pipeline connecting the second outlet to the downstream component.

[0014] Furthermore, a sensor is installed on the pipeline connecting the second outlet to the downstream component, the sensor being used to detect the concentration and flow rate of oxygen.

[0015] Beneficial effects: This invention provides a flow control device for improving the oxygen concentration of a PSA oxygen generator under low flow conditions. By setting a diversion valve in the device, instead of restricting the flow rate of oxygen discharged from the molecular sieve tank, a diversion operation is implemented to discharge or recycle excess oxygen from the second outlet, rather than restricting gas output. This ensures that the oxygen generator always operates within the working flow range with the highest oxygen concentration, thereby avoiding the "nitrogen breakdown" effect and ensuring that the oxygen concentration can meet the usage requirements under low flow conditions. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of a flow control device for improving oxygen concentration in a PSA oxygen generator under low flow conditions, as disclosed in this invention. Figure 2This is a schematic diagram of the flow divider valve disclosed in Embodiment 1 of the present invention; Figure 3 This is a schematic diagram of the valve plate structure disclosed in Embodiment 1 of the present invention; Figure 4 This is a schematic diagram of the valve cover structure disclosed in Embodiment 1 of the present invention; Figure 5 This is a schematic diagram of the structure of the fixed baffle disclosed in Embodiment 1 of the present invention; Figure 6 This is a schematic diagram of the main body structure disclosed in Embodiment 1 of the present invention; Figure 7 This is a schematic diagram of the flow divider valve disclosed in Embodiment 2 of the present invention; Figure 8 This is a schematic diagram of the structure of the motor disclosed in Embodiment 2 of the present invention; Figure 9 This is a schematic diagram of the valve cover structure disclosed in Embodiment 2 of the present invention; Figure 10 This is a schematic diagram of the valve plate structure disclosed in Embodiment 2 of the present invention; Figure 11 This invention discloses a flow control device for improving oxygen concentration in a PSA oxygen generator under low flow conditions, and a line graph showing the oxygen content and flow rate of the product gas compared to a traditional needle valve flow control.

[0018] In the diagram: 1. Filter; 2. Compressor; 3. Cooler; 4. Two-position four-way solenoid valve; 5. Nitrogen silencer; 6. First molecular sieve tank; 7. Second molecular sieve tank; 8. First throttling orifice; 9. Second throttling orifice; 10. Oxygen tank; 11. Pressure reducing valve; 12. Diverter valve; 121. First outlet; 122. Second outlet; 123. Oxygen inlet; 124. Valve plate; 125. Rotating shaft; 126. Stop block; 127. Fixed baffle; 128. Limiting protrusion; 129. Main body; 1210. Valve cover; 1211. Motor; 1212. Knob; 13. Sensor; 14. Check valve. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Example 1 This embodiment provides a flow control device for improving oxygen concentration in a PSA oxygen generator under low flow conditions, such as... Figure 1As shown, it includes: compressor 2, flow divider valve 12, oxygen tank 10 and a spare molecular sieve tank (the first molecular sieve tank 6 and the second molecular sieve tank 7 are connected in parallel and work alternately). Nitrogen is absorbed through the molecular sieve tank to purify oxygen. like Figure 2 and Figure 6 As shown, the valve body of the diversion valve 12 is provided with an oxygen inlet 123, a first outlet 121 and a second outlet 122. The valve body is provided with a valve assembly, which includes a valve plate 124. The valve plate 124 divides the interior of the valve body into a first gas path for connecting the oxygen inlet 123 and the first outlet 121 and a second gas path for connecting the oxygen inlet 123 and the second outlet 122. The valve assembly can adjust the cross-sectional area of ​​the first gas path and the second gas path. In this embodiment, the valve body is composed of, for example... Figure 4 The valve cover 1210 shown and as Figure 6 The main body 129 shown is composed of a valve cover 1210 fixed on the main body 129; like Figure 1 As shown, the outlet of the compressor 2 is connected to the inlet of the molecular sieve tank, the outlet of the molecular sieve tank is connected to the inlet of the oxygen tank 10, the outlet of the oxygen tank 10 is connected to the inlet of the diverter valve 12, and the first outlet 121 is connected to the downstream component that requires oxygen, which may be an oxygen mask or a nasal cannula.

[0021] This embodiment provides a flow control device for improving the oxygen concentration of a PSA oxygen generator under low flow conditions. By setting a diversion valve 12 in the device, instead of restricting the oxygen flow rate discharged from the molecular sieve tank, a diversion operation is implemented to discharge or recycle excess oxygen from the second outlet 122, rather than restricting gas output. This ensures that the oxygen generator always operates within the working flow range with the highest oxygen concentration, thereby avoiding the "nitrogen breakdown" effect and ensuring that the oxygen concentration can meet the usage requirements under low flow conditions.

[0022] Specifically, such as Figure 2 As shown, the valve assembly also includes a fixed baffle 127 fixed on the valve body, and the fixed baffle 127 and the valve plate 124 divide the interior of the valve body into a first air passage and a second air passage. like Figure 5 As shown, the fixed baffle 127 is provided with a limiting protrusion 128, which forms a limiting groove with the inner wall of the valve body. Figure 3 As shown, the valve plate 124 is provided with a rotating shaft 125 and a stop block 126. The valve plate 124 is rotatably mounted on the fixed baffle 127 via the rotating shaft 125, and the stop block 126 can slide within the limiting groove.

[0023] Specifically, such as Figure 2 and Figure 3As shown, the valve assembly also includes a knob 1212, which is fixed to the top of the rotating shaft 125 (the knob 1212 is fixed on the part of the rotating shaft 125 that passes through the valve cover 1210). Rotating the knob 1212 can drive the valve plate 124 to rotate.

[0024] Specifically, such as Figure 1 As shown, the compressor 2 is provided with a filter 1 at the inlet to filter out impurities and particles in the air, and a cooler 3 is provided at the outlet of the compressor 2 to cool the pressurized air pumped out from the compressor 2.

[0025] Specifically, such as Figure 1 As shown, it also includes a two-position four-way solenoid valve 4. The four ports of the two-position four-way solenoid valve 4 are respectively connected to the outlet of the compressor 2, the nitrogen silencer 5 and the inlet of the two molecular sieve tanks. The gas flow direction is controlled by the two-position four-way solenoid valve 4 and the exhaust noise is eliminated by the nitrogen silencer 5.

[0026] Specifically, such as Figure 1 As shown, the outlet of the molecular sieve tank is provided with a throttling orifice (the throttling orifice can be provided by a throttling orifice plate). The first molecular sieve tank 6 and the second molecular sieve tank 7 correspond to the first throttling orifice 8 and the second throttling orifice 9, respectively, in order to maintain the pressure difference between the molecular sieve tank and the rear end.

[0027] Specifically, such as Figure 1 As shown, the oxygen tank 10 is equipped with a pressure reducing valve 11 at the outlet to stabilize the pressure of the output oxygen.

[0028] Specifically, the second outlet 122 is connected to the atmosphere, and excess product gas is directly discharged into the atmosphere; Or, such as Figure 1 As shown, the second outlet 122 is connected to the inlet of the compressor 2 via a hose, which increases the oxygen content of the air entering the compressor 2 and indirectly increases the oxygen concentration, thereby improving the oxygen concentration of the product gas generated by the oxygen generator at all flow rates.

[0029] Specifically, such as Figure 1 As shown, a one-way valve 14 is provided on the pipeline connecting the second outlet 122 to the downstream component to prevent gas backflow.

[0030] Specifically, such as Figure 1 As shown, a sensor 13 is provided on the pipeline connecting the second outlet 122 to the downstream component. The sensor 13 is used to detect the oxygen concentration and flow rate. The sensor 13 can be a sensor that integrates oxygen concentration detection and flow rate detection, or it can be an oxygen concentration sensor and a flow rate sensor connected in series.

[0031] The working principle of a PSA (Pressure Swing Adsorption) oxygen generator is based on the selective adsorption of nitrogen by molecular sieves, separating oxygen through alternating pressure changes. Its workflow is as follows: Air pretreatment: Ambient air first passes through filter 1 to remove particulate matter, and then enters compressor 2 for pressurization. The high-temperature compressed air is cooled by cooler 3 to prevent the molecular sieve from failing due to high temperature. Adsorption and desorption cycle: When the first molecular sieve tank 6 is in the high-pressure stage, the second molecular sieve tank 7 is in the low-pressure regeneration stage. Specifically, compressed air is switched into the first molecular sieve tank 6 through the two-position four-way solenoid valve 4. The zeolite molecular sieve in the tank adsorbs nitrogen under high pressure, and oxygen (purity 90%~95%) enters the subsequent process through the first throttle orifice 8. Meanwhile, the second molecular sieve tank 7 is switched to a low-pressure state through a two-position four-way solenoid valve 4, and the adsorbed nitrogen is released and discharged through the nitrogen silencer 5. The first molecular sieve tank 6 and the second molecular sieve tank 7 alternately switch between adsorption / desorption states through the two-position four-way solenoid valve 4 to achieve continuous oxygen production. Oxygen collection and regulation: Oxygen produced by the molecular sieve tank is stored in oxygen tank 10. The pressure is then adjusted by pressure reducing valve 11, the output rate is controlled by flow divider valve 12, the oxygen purity is monitored in real time by sensor 13, a one-way valve prevents backflow, and finally it is output to the user. The produced oxygen is split by the diversion valve 12. One part is output to the user, and the other part flows back to the inlet of the compressor 2 to increase the oxygen concentration of the raw material gas, which in turn increases the oxygen concentration of the product gas.

[0032] For the same equipment, two different flow control methods (traditional needle valve flow control and the diversion flow control adopted in this application) were used. Each group was repeated three times and the average value was taken. The data on the relationship between the oxygen content of the produced gas and the flow rate are shown in the table below.

[0033]

[0034] like Figure 11 As shown, it can be clearly seen that at low flow rates, unlike traditional needle valve-type flow control PSA oxygen generators, the oxygen content of the product gas produced by the device disclosed in this application does not fluctuate significantly.

[0035] Example 2 This embodiment provides a flow control device for improving oxygen concentration in a PSA oxygen generator under low flow conditions. Its main structure and working principle are the same as those in Embodiment 1, with the following differences: In Embodiment 1, the valve assembly further includes a knob 1212, which can drive the valve plate 124 to rotate.

[0036] In this embodiment, such as Figure 7 and Figure 8 As shown, the valve assembly also includes a motor 1211, which is a stepper motor. The motor 1211 is located on the outside of the valve body, and the output shaft of the motor 1211 is used to drive the valve plate 124 to rotate. like Figure 9 As shown, the valve cover 1210 is provided with screw holes for mounting the motor 1211, such as... Figure 10 As shown, the top of the rotating shaft 125 is provided with an output shaft connection hole. After the output shaft of the motor 1211 passes through the valve cover 1210, it is inserted into the output shaft connection hole, driving the valve plate 124 to rotate.

[0037] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A flow control device for improving oxygen concentration in a PSA oxygen generator under low flow conditions, characterized in that, include: Compressor (2), flow divider (12), oxygen tank (10), and a spare molecular sieve tank; The valve body of the diverter valve (12) is provided with an oxygen inlet (123), a first outlet (121) and a second outlet (122). The valve body is provided with a valve assembly, which includes a valve plate (124). The valve plate (124) divides the interior of the valve body into a first gas path for connecting the oxygen inlet (123) and the first outlet (121) and a second gas path for connecting the oxygen inlet (123) and the second outlet (122). The valve assembly can adjust the cross-sectional area of ​​the first gas path and the second gas path. The outlet of the compressor (2) is connected to the inlet of the molecular sieve tank, the outlet of the molecular sieve tank is connected to the inlet of the oxygen tank (10), the outlet of the oxygen tank (10) is connected to the inlet of the diverter valve (12), and the first outlet (121) is connected to the downstream component.

2. The flow control device for improving oxygen concentration in a PSA oxygen generator under low flow conditions according to claim 1, characterized in that, The valve assembly also includes a fixed baffle (127) fixed on the valve body, the fixed baffle (127) and the valve plate (124) dividing the interior of the valve body into a first air passage and a second air passage; The fixed baffle (127) is provided with a limiting protrusion (128), which forms a limiting groove with the inner wall of the valve body. The valve plate (124) is provided with a rotating shaft (125) and a stop block (126). The valve plate (124) is rotatably mounted on the fixed baffle (127) through the rotating shaft (125), and the stop block (126) can slide in the limiting groove.

3. The flow control device for improving oxygen concentration in a PSA oxygen generator under low flow conditions according to claim 2, characterized in that, The valve assembly also includes a motor (1211), which is located on the outside of the valve body and the output shaft of the motor (1211) is used to drive the valve plate (124) to rotate; or, the valve assembly also includes a knob (1212), which can drive the valve plate (124) to rotate.

4. The flow control device for improving oxygen concentration in a PSA oxygen generator under low flow conditions according to claim 1, characterized in that, The compressor (2) is provided with a filter (1) at its inlet and a cooler (3) at its outlet.

5. The flow control device for improving oxygen concentration in a PSA oxygen generator under low flow conditions according to claim 1, characterized in that, It also includes a two-position four-way solenoid valve (4), the four ports of which are respectively connected to the outlet of the compressor (2), the nitrogen silencer (5) and the inlet of the two molecular sieve tanks.

6. The flow control device for improving oxygen concentration in a PSA oxygen generator under low flow conditions according to claim 1, characterized in that, The molecular sieve tank is equipped with a throttling orifice at its outlet.

7. The flow control device for improving oxygen concentration in a PSA oxygen generator under low flow conditions according to claim 1, characterized in that, The oxygen cylinder (10) is equipped with a pressure reducing valve (11) at its outlet.

8. The flow control device for improving oxygen concentration in a PSA oxygen generator under low flow conditions according to claim 1, characterized in that, The second outlet (122) is connected to the atmosphere; or, the second outlet (122) is connected to the inlet of the compressor (2).

9. The flow control device for improving oxygen concentration in a PSA oxygen generator under low flow conditions according to claim 1, characterized in that, The second outlet (122) is connected to a downstream component via a check valve (14).

10. A flow control device for improving oxygen concentration in a PSA oxygen generator under low flow conditions according to claim 1, characterized in that, A sensor (13) is provided on the pipeline connecting the second outlet (122) to the downstream component. The sensor (13) is used to detect the concentration and flow rate of oxygen.

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