JPS6111882B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an intermittent ozone supply device.

Ozone has a strong oxidizing power and is non-polluting, so it has come to be widely applied in the fields of environmental treatment, chemical industry, etc. When using such ozone, there are two methods: continuous use and intermittent use, depending on the purpose. Intermittent use of ozone is a method that can prevent organisms such as algae and shellfish from adhering to the cooling water pipes of power plants, chemical factories, and machine factory equipment, reducing their function by reducing heat exchange efficiency and clogging the pipes. Intermittently (1 to 1 It is used to suppress the reproduction of the above organisms by injecting ozone once to several times every few days for one minute. When using ozone intermittently in this way, if the ozone generator is also operated intermittently, a large ozone generator with high equipment costs will be required, so generally a small ozone generator is used. An intermittent ozone supply device is used that stores the generated ozone in low-temperature silica gel for a long period of time (1 to several days), and when necessary, desorbs the ozone all at once in a few minutes and injects it into the water to be treated. It is being said.

FIG. 1a is a system diagram showing a conventional intermittent ozone supply device, and FIG. 1b is a vertical sectional view showing its adsorption/desorption tower. 3 is a circulation blower that circulates oxygen from this adsorption/desorption tower to the ozone generator 1; 4 is an oxygen supply source to the ozone generator 1; 5a to 5d are electromagnetic valves; 6 is the adsorption/desorption tower 2;
7 is a heater installed in this hot brine tank; 8 is a pump that sends the warm brine to the adsorption/desorption tower 2; 9 is a refrigerator that cools the adsorption/desorption tower 2; 10 is an adsorption/desorption tower; This is a water ejector that sucks ozone from the desorption tower 2. Also, Figure 1b
2a is an ozone adsorbent filled in the adsorption/desorption tower 2, and silica gel is usually used. 2b is an inner cylinder that accommodates this ozone adsorbent;
2d is an adsorption/desorption brine tank provided between the inner and outer cylinders, and 2e is an evaporation pipe that is in close contact with the inner cylinder 2b and connected to the refrigerator 9.

Next, the operation of the above device will be explained with reference to the operation sequence shown in FIG. This operation is divided into an ozone adsorption operation and an ozone desorption operation, and the arrows represent the operating time of the device, and in the case of a solenoid valve, indicate the open state.

First, to explain the ozone adsorption operation, the ozone generator 1, the adsorption/desorption tower 2, and the circulation blower 3 constitute an oxygen circulation system in this order, and the solenoid valve 5a,
5b is open, and solenoid valves 5c and 5d are closed. Oxygen is supplied from the oxygen supply source 4 so that the system pressure is constant (usually 2ata), and the ozonized oxygen generated by the ozone generator 1 is introduced into the adsorption/desorption tower 2, where only ozone is It is adsorbed by the ozone adsorbent 2a. A so-called oxygen recycling system is constructed in which the oxygen (95% or more) that has not been ozonized by the ozone generator 1 is returned to the ozone generator 1 by a circulation blower 3 and used for circulation. Since the ozone adsorbed by the adsorption/desorption tower 2 increases as the temperature of the silica gel decreases, the ozone is cooled to -30° C. or higher by the refrigerator 9 during the ozone adsorption period. Normally, this cooling is performed by evaporating freon compressed by the refrigerator 9 in the evaporator tube 2e that is in close contact with the inner cylinder 2b.

In this way, ozone is adsorbed in the adsorption/desorption tower 2, but when the ozone adsorbent 2a approaches ozone adsorption saturation after a desired period of time, ozone leaks from the gas outlet of the adsorption/desorption tower 2. come. If this leak starts and the suction operation continues, the device will lose power, so the suction operation is ended and the desorption operation is started. Note that this adsorption time is set in advance.

Next, the ozone desorption operation will be explained. When the ozone desorption operation begins, the solenoid valves 5a and 5b close.
The solenoid valves 5c and 5d open, water flows into the water ejector 10, and the ozone in the adsorption/desorption tower 2 is sucked under reduced pressure and dissolved in water to produce ozone water. At the same time, the pump 8 operates, and the brine in the warm brine tank 6, whose temperature has been raised in advance by the heater 7 (usually 50°C), flows into the adsorption/desorption brine tank 2d, which adsorbs ozone that had been cooled to a low temperature during the adsorption operation. The temperature of the agent 2a is increased to promote ozone desorption.

The ozone adsorption operation takes a long time (1 to several days), but the ozone desorption takes place in the adsorption/desorption tower 2 as described above.
This can be done in a short time (several minutes) by increasing the temperature and reducing the pressure.
After the desorption is completed, the adsorption operation starts again, the circulation system is filled with oxygen from the oxygen supply source 4, the adsorption/desorption tower 2 is cooled again by the refrigerator 9, and the ozone adsorption operation begins.

In such an intermittent ozone supply device, when ozone is injected into the water pipe system in order to desorb the adsorption/desorption tower 2 under source pressure (below atmospheric pressure), water flows backwards into the adsorption/desorption tower 2. There is a possibility of entering. If water flows back into the adsorption/desorption tower 2 and enters, the silica gel adsorbs a large amount of ozone and oxygen, so there is a danger that it will be decomposed (ozone) or desorbed all at once, leading to an explosion. Even if it does not explode, silica gel containing water no longer has the ability to adsorb ozone, so it is necessary to replace the silica gel. Therefore, in such an intermittent ozone supply device, it is required that water never flow back into the adsorption/desorption tower.

Taking a specific example of water flowing back into silica gel, we will explain conventional countermeasures against it. In the cases of Figures 1 and 2, the pressure inside the adsorption/desorption tower 2 is usually 0.1 ata at the end of the ozone desorption period.
Although the condition is such that water in the water pipe can flow backward during the oxygen filling period, the solenoid valve 5c is in a closed state, so water intrusion is suppressed. Normally, solenoid valves have directionality and can mainly stop flow in only one direction, so generally a third valve is used.
Two solenoid valves 5c1 and 5c2 as shown in the figure
are connected in the opposite direction. Of these, solenoid valve 5c
1 is mainly used to prevent ozone and oxygen from leaking out of the system during the ozone adsorption period, and is also a solenoid valve 5.
c2 is for preventing water (or air, etc. from outside the system) from entering during the period from the end of the ozone desorption period until the system of the apparatus is filled with oxygen. In this way, two solenoid valves 5c1 and 5c2
is used to prevent water from flowing back into the adsorption/desorption tower 2. However, if, for example, a foreign object gets caught in the valve body of the solenoid valve 5c and it does not close completely, during the oxygen filling period in the sequence shown in FIG. There is a risk of water flowing backwards.

The present invention was made in order to eliminate the drawbacks of the conventional ones as described above, and it is possible to continue the suction operation even after the desorption operation is completed until the pressure on the suction side becomes lower than the pressure in the adsorption/desorption tower. It is an object of the present invention to provide an intermittent ozone supply device that can eliminate the danger of water backflow.

The basic structure of the intermittent ozone supply apparatus of the present invention is the same as that shown in FIG. 1, but its operation sequence is shown in FIG. The difference between this sequence and the sequence shown in FIG. 2 is that the operation period of the water ejector 10 is not ended at the same time as the end of the ozone desorption period, and the adsorption/desorption tower 2 is filled with oxygen after the solenoid valve 5c is closed due to the end of the desorption operation. The process is stopped when the pressure inside the adsorption/desorption tower 2 becomes higher than the water pressure on the suction side, that is, the water pressure in the system into which the desorbed ozone is injected.

The operation of the intermittent ozone supply device configured as described above is basically the same as that in FIGS. 1 and 2, but after the ozone desorption period ends, the adsorption/desorption tower 2 is filled with oxygen. When the oxygen pressure in the adsorption/desorption tower 2 becomes higher than the water pressure on the suction side, that is, in the system into which desorbed ozone is injected, the water ejector 10
stops. As a result, a condition where water flows backward from the water ejector 10 portion does not occur, and the risk of backflow as in the conventional case is eliminated. Furthermore, in this case, since there is no condition regarding the flow direction from the water ejector 10 to the adsorption/desorption tower 2, only 11 solenoid valves 5c as shown in FIG. 3 are required as the solenoid valves 5c. In particular, the solenoid valve 5c uses a so-called non-leak solenoid valve that completely shuts off gas or liquid when it is closed, and since this solenoid valve is expensive and has a short lifespan, it is If only one device is required, there is an advantage that not only is there no risk of water backflow, but the cost of the device can be reduced.

FIG. 5 is a system diagram showing a specific configuration that determines the conditions for stopping the operation of the water ejector 10. In the figure, 11a is a pressure detector that detects the pressure of the adsorption/desorption tower 2, and 11b is the suction side, that is, the desorption side. A pressure detector 12 detects the water pressure in the system into which the desorbed ozone is injected, and a pressure detector 12 determines the pressure difference between these two pressure detectors to determine whether the internal pressure of the adsorption/desorption tower 2 is on the suction side, that is, the desorbed ozone is This is a control device that issues an electrical signal when the water pressure in the system is higher than the water pressure being injected into the system.

In the above configuration, the pressure detectors 11a, 11
The pressures detected at point b are compared in the control device 12, and the pressure detected by the detector 11a is compared with the pressure detected by the detector 11b.
When the pressure becomes higher than the detector pressure, the controller 1
An electric signal is issued from 2 to stop the water ejector 10. In this case, if the water pressure in the water pipe system does not fluctuate, naturally only the pressure detector 11a is sufficient. In addition, if the oxygen filling rate is measured in advance and the time required for the internal pressure of the adsorption/desorption tower 2 to reach a predetermined pressure is known, a timer can be set so that the water ejector 10 operates for a predetermined time even after the ozone desorption operation is completed. may be equipped.

Although the above description has been made regarding an example in which vacuum suction from the adsorption/desorption tower 2 is performed by the water ejector 10, it goes without saying that the same applies even if the suction is performed by a diaphragm pump, a vacuum pump, or the like. Furthermore, the format and structure of the ozone generator 1, adsorption/desorption tower 2, etc. are not limited.

Further, the intermittent ozone supply device of the present invention is not limited to the above-mentioned applications, but can be applied to all kinds of applications.

As described above, according to the present invention, water backflow can be prevented by performing the suction operation until the pressure on the suction side becomes lower than the pressure in the adsorption/desorption tower, thereby increasing the reliability of the intermittent ozone supply device. The effect is great because the device can be manufactured at low cost.

[Brief explanation of the drawing]

Fig. 1a is a system diagram showing a conventional intermittent ozone supply device, b is a vertical sectional view showing its adsorption/desorption tower, and Fig. 2
The figure is a sequence diagram of Figure 1, Figure 3 is a detailed system diagram showing the configuration of the solenoid valve used in the actual device, Figure 4 is a sequence diagram of an intermittent ozone supply device according to an embodiment of the present invention, FIG. 5 is a system diagram showing a specific configuration for obtaining a signal of the time to stop the water ejector in one embodiment of the present invention. In each figure, the same reference numerals indicate the same or equivalent parts, 1 is an ozone generator, 2 is an adsorption/desorption tower, 6 is a warm brine tank, 9 is a refrigerator, 11a, 11b are pressure detectors, and 12 is a control device. be.

Claims (1)

[Scope of Claims] 1. An ozone generator that generates ozonized oxygen from raw material oxygen, an adsorption/desorption tower capable of adsorbing ozone from the ozonized oxygen and desorbing ozone, and an ozone generation device that generates ozone by the ozone adsorption/desorption tower. a system for returning adsorbed oxygen to the ozone generator; a means for cooling the adsorption/desorption tower during ozone adsorption; and a system for raising the temperature of the adsorption/desorption tower during ozone desorption compared to that during adsorption and suctioning under reduced pressure. In an intermittent ozone supply device having a means for desorbing ozone, after the desorption operation is completed, oxygen is supplied to the adsorption/desorption column, and the pressure in the system into which the desorbed ozone is injected is reduced to the level of the adsorption/desorption column. An intermittent ozone supply device comprising: a reduced pressure suction device that performs a suction operation until the pressure becomes lower than the pressure of 2 A pressure detector detects the pressure in the system into which desorbed ozone is injected, a pressure detector detects the pressure in the adsorption/desorption tower, and a pressure detector detects the pressure in the system into which desorbed ozone is injected. 2. The intermittent ozone supply device according to claim 1, further comprising a device that issues a signal when the pressure becomes higher than the pressure.