JPH0350166B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an oxygen-enriched air supply device that supplies oxygen-enriched air using an oxygen selective permeation membrane to an oxygen-enriched air consumption device.

Recently, attempts have been made to directly concentrate oxygen from air using polymer membranes. (For example, JP-A-49-
10192, etc.) This method can easily obtain oxygen-enriched air with an oxygen concentration of 23-30%, so it is suitable for oxygen-enriched air consumption equipment such as combustion, treatment of people with respiratory disorders, sludge aeration treatment, etc. It can be widely used. Conventionally, as a device for supplying oxygen-enriched air to the above-mentioned oxygen-enriched air consumption device, as shown in FIGS. exposed to air;
A device is known in which the secondary side is connected to the vacuum pump 3 while maintaining airtightness. In such a device, when the vacuum pump is operated, air is drawn into the module and enters the module, and the air that permeates through the membrane becomes oxygen-enriched air from the outlet of the vacuum pump and is supplied to the next oxygen-enriched air consumption device 4. be done. In order to make the amount of enriched air supplied to the oxygen-enriched air consumption device correspond to the amount of enriched air consumed in the device, a second step is required.
The amount of oxygen-enriched air passing through the membrane can be controlled by adjusting the control valve 5 installed on the absorption side of the vacuum pump as shown in the figure, or the amount of oxygen-enriched air passing through the membrane can be controlled as shown in Figure 1. is kept constant and the excess oxygen-enriched air is returned to the absorption side of the vacuum pump 3 by controlling the control valve 5 attached to the circulation pipe 6. However, in the device shown in FIG. 2, when the control valve 5 is controlled to reduce the amount of oxygen-enriched air that permeates through the oxygen selectively permeable membrane 1, the pressure difference between the primary side and the secondary side becomes small, and the air permeates through the membrane. The disadvantage was that the oxygen concentration of the oxygen-enriched air decreased. On the other hand, in the device shown in Figure 1, excess oxygen-enriched air is returned to the suction side of the vacuum pump to maintain a constant amount of air passing through the oxygen selectively permeable membrane. Although the differential pressure becomes constant and the oxygen concentration of the oxygen-enriched air can be maintained at a constant value, the power consumption of the vacuum pump remains unchanged despite fluctuations in the amount of oxygen-enriched air consumed. The disadvantage is that the manufacturing cost per unit volume increases as the consumption of enriched air decreases.

The inventor of the present invention has arrived at the present invention as a result of extensive studies aimed at providing an oxygen-enriched air supply device that eliminates the above-mentioned drawbacks of conventional devices. That is, the present invention provides a plurality of oxygen-enriched modules arranged in a module storage chamber having an open end to the outside, an oxygen-enriched air outlet pipe connected to each module via a shutoff valve, and a plurality of oxygen-enriched air outlet pipes connected to each module via a shutoff valve. A collection pipe for the derived oxygen-enriched air, a rotary vacuum pump having a variable speed mechanism connected to the collection pipe, a consumption amount detection means for the oxygen-enriched air transferred by the vacuum pump, A rotation speed adjustment signal is sent to the vacuum pump so that the discharge amount is approximately the same as the amount of oxygen-enriched air detected by the consumption amount detection means, and the optimal membrane area is selected in accordance with the amount of oxygen-enriched air. This oxygen-enriched air supply device is equipped with a control means for transmitting opening/closing signals to shutoff valves connected to various modules.

According to the present invention, with the above configuration, it is possible to obtain oxygen-enriched air whose oxygen concentration is always constant even when the consumption amount of oxygen-enriched air changes, and it is also possible to keep the manufacturing cost per unit volume constant. It is.

Next, one embodiment of the present invention will be described with reference to the drawings.

Figure 3 is a schematic diagram of an oxygen-enriched air supply system assuming a turndown ratio (actual usage amount/rated flow rate) of 1/4. a, 8-b, 8-c, 8-
d are arranged in a module housing chamber 10 having an open end open to the outside. Each of the above modules accommodates an oxygen selective permeation membrane that is subdivided at the same ratio as the turndown ratio, which is set in consideration of fluctuations in the amount of oxygen-enriched air consumed. However, the ratio of subdivision of this oxygen selectively permeable membrane is not necessarily limited to the turndown ratio, but is determined to achieve the highest efficiency under the flow fluctuation conditions of the oxygen-enriched air consumption device, especially in the area of maximum use. All you have to do is choose. Furthermore, the oxygen selectively permeable membranes accommodated in each module do not have to have the same area.

When the ventilation fan 11 provided at the open end of the module storage chamber 10 is operated, external air passes through the filter 12 to remove dust and is supplied to the module storage chamber 10. When the vacuum pump 3 is operated, the air in the module storage chamber is sucked through the oxygen selective permeation membrane housed inside the module, and the air is drawn out through the outlet pipes 13-a and 13-a connected to the secondary side of each module.
13-b, 13-c, 13-d and then collected in the collection pipe 15, which is then supplied to the oxygen-enriched air consumer 4. On the other hand, the remaining oxygen-depleted air in the module storage chamber is forcibly exhausted by a ventilation fan, so fresh air is always supplied to the module storage chamber. 7-a, 7-b, and 7-c are cutoff valves attached to the outlet pipes. In FIG. 3, the outlet pipe 13-d connected to the oxygen enrichment module 8-d
is not equipped with a shutoff valve. This uses the module 8-d as a base load, and
This is to reduce equipment costs. On the other hand, it is also possible to attach shutoff valves to all the lead-out pipes connected to each module and to sequentially switch and use them.

The vacuum pump 3 used in the present invention needs to be a bilobal, trilobal, vane, screw, or pendulum-type rotary vacuum pump that has a variable speed mechanism that can adjust the discharge amount. Among them, bilobal and trilobal vacuum pumps have a proportional relationship between the number of rotations and the discharge amount, so it is easy to adjust the discharge amount.

The means for detecting the usage amount of oxygen-enriched air in the oxygen-enriched air consumption device 4 is, for example, a flow meter installed in the enriched air supply piping to the enriched air consumption device to directly detect the consumption amount of enriched air. Alternatively, as shown in Fig. 3, the combustion temperature detector in the device, which has been conventionally used to adjust the amount of fuel air and fuel supplied into the device, can be used as a means for detecting the amount of enriched air consumed. It can also be used as

The signal detected by the detection means is input to the control means 9. The control means transmits a rotation speed adjustment signal to the vacuum pump so that the consumption amount of enriched air and the discharge amount of the vacuum pump 3 that supplies enriched air to the enriched air consumption device 4 are approximately the same, and at the same time, the oxygen According to a module selection program set in advance to select the optimum membrane area corresponding to the consumption amount of enriched air, signals are sent to appropriately open and close the shutoff valves connected to each outlet pipe.

In such a configuration, when the amount of enriched air consumed by the oxygen-enriched air consumption device 4 fluctuates, the amount of variation is detected by the enriched air detection means, and upon receiving the detection signal, the control means controls the vacuum pump. The rotation speed is adjusted so that the discharge volume of the enriched air is approximately the same as the consumption of enriched air, and the shutoff valves connected to each outlet pipe are opened and closed as appropriate according to a preset program. The optimal module corresponding to the amount of air consumption is selected. Therefore, the differential pressure between the primary and secondary sides of the membrane is always kept constant, and the oxygen concentration can be kept constant regardless of fluctuations in the amount of enriched air consumed. Furthermore, in order to prevent equipment damage in the event that the pressure on the downstream side of the oxygen selectively permeable membrane abnormally decreases due to abnormal operation, it is preferable to install a vacuum breaker valve on the suction side of the vacuum pump.

As described above, the device of the present invention is an extremely practical device that can always keep the oxygen concentration constant despite fluctuations in the amount of oxygen-enriched air consumed, and can also keep the manufacturing cost constant per unit volume. It is a device.

[Brief explanation of drawings]

Figures 1 and 2 are system diagrams of conventional equipment;
FIG. 3 is a system diagram of the apparatus of the present invention. 3...Vacuum pump, 4...Oxygen enriched air consumption device, 7...Shutoff valve, 8...Oxygen enrichment module,
9...Control means, 10...Module storage chamber, 1
3...Derivation piping, 15...Collection piping.

Claims (1)

[Claims] 1 A plurality of oxygen-enriched modules arranged in a module storage chamber having an open end to the outside, an oxygen-enriched air outlet pipe connected to each module via a shutoff valve, and an oxygen-enriched air outlet pipe connected to each module via a shutoff valve, and an oxygen-enriched air outlet pipe connected to each module via a shutoff valve. a rotary vacuum pump having a variable speed mechanism connected to the collection pipe;
a consumption amount detection means of the oxygen-enriched air transferred by the vacuum pump; and a rotation speed adjustment signal to the vacuum pump so that the discharge amount is approximately the same as the amount of oxygen-enriched air detected by the consumption amount detection means. An oxygen-enriched air supply device comprising control means for transmitting open/close signals to shutoff valves connected to various modules so as to select the optimum membrane area corresponding to the amount of oxygen-enriched air.