JPS6240286B2 - - Google Patents

Description

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

A large amount of cooling water is used in power plants, chemical industries, etc., but microorganisms and algae in the water cause slime problems, clogging pipes and reducing heat exchange efficiency. Application of highly concentrated ozonated water is being considered as a preventive measure for this type of problem. In order to generate this highly concentrated ozone water, rather than using a large-capacity ozone generator, it is necessary to use a small and small-capacity ozone generator and use the generated ozone as an adsorbent for a long period of time. The so-called intermittent ozone supply method, in which the accumulated ozone is removed from the adsorbent at once to produce highly concentrated ozone water, is advantageous in terms of equipment costs and operating costs.

An example of a typical conventional intermittent ozone supply device will be explained with reference to FIG. In the figure, 1 is an ozone generator, 2 is an oxygen supply source, 3 is a circulation blower, 4 is an adsorption/desorption tower, 5-1 to 5-7 are switching valves, 6 is a water ejector, 7 is a warm brine tank, and 8 is a A heating source, 9 a pump for hot brine, 10 a pump for cold brine, 11 a cold brine tank, 12 a cooler, 13 a refrigerator, 14 a compressor, 15 an expansion valve, 16 a condenser, 17 is Juan. The adsorption/desorption tower 4 has a double cylinder structure, of which the inner cylinder is filled with an ozone adsorbent, and the outer cylinder is filled with a heat medium. Furthermore, silica gel is generally used as the adsorbent, and ethylene glycol or alcohol is used as the heat medium. Note that the circulation blower 3, the ozone generator 1, and the adsorption/desorption tower 4 constitute one circulation system in this order.

Next, the operation will be explained. This operation includes two operations: an ozone adsorption operation and an ozone desorption operation.

First, the suction operation will be explained. Oxygen is supplied from the oxygen supply source 2 to the inside of the circulation system at a constant pressure. At this time, the switching valves 5-1 and 5-2 are open.
When oxygen is passed through the circulation system by the circulation blower 3, part of the oxygen is converted into ozone by silent discharge while passing through the discharge gap of the ozone generator 1, and becomes ozonized oxygen. This ozonized oxygen is transported to the adsorption/desorption tower 4. The adsorbent in the ozone adsorption/desorption tower 4 selectively adsorbs ozone, and the remaining oxygen is returned to the circulation blower 3 via the switching valve 5-1. Oxygen consumed as ozone is replenished from the oxygen supply source 2. At this time, the temperature of the ozone adsorbent is cooled to -30°C or lower by a cooling source. In this operation, the cold brine in the cold brine tank 11 that has been cooled by the refrigerator 13 is circulated by the pump 10 for cooling.

The refrigerator 13 compresses a heat medium such as fluorocarbon or ammonia gas to high temperature and high pressure using a compressor 14, exchanges heat with water or air in a condenser 16, expands the cooled heat medium in an expansion valve 15, and transfers the heat medium to a cooler 12. It evaporates within the cold brine tank 9 and exchanges heat with the brine in the cold brine tank 9 to cool it down. The amount of ozone adsorbed by the above-mentioned adsorbent varies greatly depending on the temperature. For example, when the temperature is lowered, the amount of ozone adsorbed increases, and conversely, when the temperature is increased, the amount of ozone adsorbed is decreased. Therefore, when desorbing ozone, the temperature of the adsorbent is increased.

When the adsorbent in the ozone adsorption/desorption tower 4 adsorbs ozone close to the saturated amount of adsorption, the desorption operation begins.

In the desorption operation, the ozone generator 1, circulation blower 3, cold brine pump 10, and refrigerator 13 stop operating, and the switching valves 5-1, 5-2, 5-4, and 5 stop operating.
-5 is closed, switching valves 5-6 and 5-7 are opened, and the warm brine in the warm brine tank 7 is conveyed by the pump 9 into the adsorption/desorption tower 4 to raise the temperature of the adsorbent. Then, the switching valve 5-3 is opened, and while the ozone in the adsorption/desorption tower 4 is depressurized and sucked by the water jet ejector 6, the water and ozone are mixed by the water jet ejector and sent as ozone water to the point of use. In this way, when the remaining ozone in the adsorption/desorption tower 4 becomes less, the desorption period ends, and the operation returns to the initial adsorption operation, and the operation is repeated continuously.

However, a drawback of the conventional apparatus described above is that the operating cost of the apparatus is high. During the ozone adsorption process, the temperature of the adsorption/desorption tower is cooled by a refrigerator so that ozone can be easily adsorbed, and during the desorption process, it is heated by a heating source 8 so that ozone can be easily desorbed. That is,
During ozone adsorption, the temperature is cooled to below -30°C, and during desorption, the temperature is raised to above 60°C. Because this temperature difference is extremely large, the power required to cool and heat the adsorption/desorption tower is limited to the heat capacity of the equipment. Considering the heat capacity of brine, the power and adsorption required for ozone generation,
It accounts for several tens of percent of the total power required for one cycle of attachment and detachment. Therefore, the operating efficiency of the device is low.

Further, at the time the desorption process is completed, the temperature of the adsorption/desorption tower has risen to 60°C or higher. Therefore, the temperature of the warm brine tank is very high when it is in operation.
If the refrigerator is operated at this temperature, the refrigerator will be operated under overload, and the pressure of the heat medium, fluorocarbon or ammonia gas, will rise to a higher pressure than in a steady state. In other words, the refrigerator becomes unable to operate stably, and the refrigerator protection switch is activated to stop the refrigerator. One way to deal with this problem is to improve the performance of the condenser, but this requires control of the expansion valve. Expansion valve control is generally unsuitable because it requires complicated control, and the condenser capacity increases, but ozone adsorption is only required to keep the temperature below -30°C, which accounts for most of the operating time of the refrigerator. The equipment must be too large compared to the capacity of the condenser.

The present invention has been made in order to eliminate the above-mentioned conventional drawbacks, and provides an intermittent ozone supply device in which the operating cost of the device is reduced by using condensation heat of a refrigerator as a heat source for warm brine. It is an object.

An embodiment of the present invention will be described below with reference to FIG. Note that the same parts as in FIG. 1 are given the same reference numerals, and the explanation will be omitted.

The present invention resides in that, in the apparatus shown in FIG. 1, the warm brine tank 7 is equipped with a heat exchanger 18 that uses the condensation heat of the refrigerator 13 as a heat source for the warm brine.

Next, the operation will be explained. In the ozone adsorption operation, a cold brine tank 1 is cooled by a refrigerator 13.
The brine in the adsorbent is flowed into the adsorption/desorption tower by the pump 10 to lower the temperature of the adsorbent. The heat of condensation compressed to high temperature and high pressure by the compressor 14 of the refrigerator 13 is sent to the warm brine tank 7, and the heat exchanger 18 exchanges heat with the brine. This condensation heat is stored in the brine as a heat source during desorption. The heat of condensation (refrigerant gas) generated by the compressor 14 is at a high temperature of around 100°C, and the brine temperature in the warm brine tank 7 is low at the beginning of the adsorption operation because it has undergone heat exchange with the adsorption/desorption tower. Because of this, the temperature difference is very large and heat exchange can be performed efficiently. The amount of heat exchanged is
It is proportional to the heat transfer area of the heat exchanger and the temperature difference.
Therefore, even if the heat transfer area is constant, if the temperature difference is large, more heat can be transferred.
Furthermore, once the adsorption/desorption tower is cooled, the refrigerator only operates to compensate for heat loss in order to maintain the low temperature. In this case, a small capacity condenser is sufficient. Additionally, the condenser can compensate for the increased temperature of the warm brine bath, which degrades the heat exchange rate.

As described above, according to the present invention, since the condensation heat of the refrigerator is used as the heat source of the warm brine, a heating source (heater) is no longer required, and power consumption is reduced, thereby reducing the operating cost of the equipment. It can be made cheaper. In addition, at the beginning of the adsorption process, the temperature of the adsorption/desorption tower rises, so the refrigerator is extremely overloaded, but the temperature of the warm brine tank is low, so the heat exchange rate is good. Therefore, there are effects such as being able to fully utilize the capacity of the condenser and continue stable operation.

[Brief explanation of the drawing]

Figure 1 is a configuration diagram of a conventional intermittent ozone supply device.
FIG. 2 is a block diagram of an intermittent ozone supply device according to the present invention. 1...Ozone generator, 4...Adsorption/desorption tower, 6...
Water ejector, 7... hot brine tank, 11... cold brine tank, 13... refrigerator, 14... compressor,
16... Condenser, 18... Heat exchanger. In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] 1. An ozone generator that generates ozonized oxygen from raw material oxygen, and an adsorption/desorption tower that adsorbs and stores ozone from the ozonized oxygen and desorbs this ozone,
Oxygen after ozone has been adsorbed by the adsorption/desorption tower is returned to the ozone generator, and ozone is desorbed and supplied from the adsorption/desorption tower. An intermittent ozone supply device whose temperature is raised by using condensation heat of a refrigerator as a heating source for the adsorption/desorption tower.