JPS6034483B2 - Intermittent ozone supply method - Google Patents

Description

[Detailed description of the invention] The present invention relates to a method for supplying interspersed ozone.

A large amount of cooling water is used in power plants, chemical industries, etc., but microorganisms and algae in the water cause slime failure, 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 to accumulate the generated ozone in an adsorbent for a long period of time. However, the so-called intermittent ozone supply method, in which the accumulated ozone is removed from the adsorbent at once to produce highly concentrated ozonated water, is advantageous in terms of equipment costs and operating costs. An example of a typical conventional ozone supply device will be explained with reference to FIG.

A is a configuration diagram of the device, and the opening indicates the operating time of the device. 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 is a cooling source, 6 is a heating source, 7 is a water ejector, and 8-1 to 8-7 are This is a group of switching valves. The adsorption/desorption monitoring tower 4 is a double tower, 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 self-circulating 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 source 2
Oxygen is constantly supplied to the circulation system at a constant pressure. The pressure at this time is normally maintained at 1.5k9/c. The switching valves 8-3 and 8-4 are open. Circulation. When oxygen is circulated in the circulation system by A3, 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 removed by the switching valve 8-
3 to the circulation blower 3. Oxygen consumed as ozone is replenished from the oxygen supply source 2. At this time,
The temperature of the ozone adsorbent is cooled to -3000 or less by the cooling source 5. This is because the amount of ozone adsorbed by the adsorbent varies greatly depending on the temperature. That is, 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.

During desorption operation, ozone generator 1, circulation blower 3, and cooling source 6 are used.
stops operating, and the switching valves 8-1, 8-2, 8-3, 8-
4 closes. Thereafter, the heat source 6 and water ejector 7 start operating, and the switching valves 8-5, 8-6, and 8-7 open. At this time, heat is applied from the heating source 6 to raise the temperature of the adsorbent so that the ozone adsorbed on the adsorbent is easily desorbed. Then, the ozone in the ozone adsorption/desorption tower 4 is sucked under reduced pressure by the water jet ejector 7, and the ozone is dispersed and dissolved in water in the water jet ejector 7, and is sent to the point of use as ozone water. At this time, the ultimate pressure inside the adsorption/desorption tower 4 due to vacuum suction is approximately -70 cmHg.
becomes. When the removal period ends in this manner, the initial suction operation is resumed and the operation is continuously repeated. However, the drawback of the conventional method described above is that ozone cannot be removed evenly over time.

In pulp bleaching and chemical plants, the higher the ozone concentration, the faster the reaction rate and the more effectively the oxidation reaction takes place. Also, in sterilization and biological treatment, the effects of injecting higher concentrations of ozone can be greatly increased. Therefore, the conditions for ozone desorption are to desorb as much of the adsorbed ozone as possible and to do so in a short period of time. However, when the adsorbent in the ozone adsorption/desorption tower adsorbs ozone to near the saturated adsorption amount, it enters desorption operation, heating the adsorbent from a heating source, and depressurizing it with a water jet ejector to remove ozone. However, ozone could not be easily desorbed in a short period of time. Figure 2 shows the relationship between the removal time and the amount of removed ozone per unit time.

With respect to the desorption time, most of the desorption amount is desorbed at the initial stage of desorption, and the desorption amount rapidly decreases. The amount of ozone desorbed from the adsorbent is only several tens of percent of the total amount of ozone adsorbed by the adsorbent before desorption. At the same time as the adsorption operation is completed and the desorption operation is started, the adsorbent is heated by the heating source 6, and in parallel with this, the adsorbent is suctioned under reduced pressure by the water jet ejector 7 to perform desorption. However, the thermal conductivity of the adsorbent itself is very poor, and heat is transferred only through contact between the adsorbents, and the ozonized oxygen gas generated between the adsorbents is also heated due to vacuum suction. movement is not that effective. Therefore, the temperature of the adsorbent hardly increases during short-time desorption. As described above, in the conventional method, the effect of heating the adsorbent on desorption of ozone is small, and most of the amount of ozone is desorbed by vacuum suction, so the amount of ozone desorbed is very small.

For example, if the adsorption action is performed without sufficiently desorbing the ozone adsorbed on the adsorbent, the ozone adsorption will reach saturation early in the adsorption period, and ozone will begin to leak from the adsorption/desorption tower.
This leaked ozone is returned to the ozone generator 1 by the circulation blower 3. A part of this ozone is decomposed by the circulation blower and the remaining returned ozone causes an increase in the amount of ozone generated. It is not added (as it is) and is extremely small. If ozone leaks from the absorption tower in this way, it can almost be considered a loss. Also,
In addition, the structure of the adsorption/desorption tower 4 may be made to have good heat transfer, but the structure becomes complicated and the apparatus becomes expensive. The present invention was conceived in order to eliminate the drawbacks of the above-mentioned conventional systems, and is designed to heat the adsorbent in the adsorption/desorption tower before ozone desorption, thereby increasing the temperature in the adsorption/desorption tower in advance. The object of the present invention is to provide a method for supplying intermittent ozone that allows ozone to be efficiently desorbed by raising the ozone.

An embodiment of the present invention will be described below with reference to FIG.

FIG. 3A is a block diagram of an apparatus for carrying out the method of the present invention, and a diagram showing operation time is shown in FIG. Note that the same parts as in FIG. 1 are given the same reference numerals, and the explanation will be omitted. This device has a configuration in which a detection sensor 9 is disposed on an absorption and extraction tower 4.

This detection sensor 9 is designed to detect the temperature inside the adsorption/desorption tower 4. Next, to explain the operation, as in the conventional method, when ozone is adsorbed to the adsorbent in the adsorption/desorption tower 4 to a level close to the saturated adsorption amount, the circulation blower 3, ozone generator 1, and cooling source 5 stop operating. The switching valves 8-1 and 8-4 close, and the ozone adsorption operation ends here. Thereafter, after the ozone adsorption operation is completed, the cut-off valves 8-5 and 8-6 are opened, the heating source 6 is activated, and the adsorbent is heated until the ozone removal operation starts, which will be described later. When the temperature of the adsorbent reaches a desired reference temperature, the following ozone removal operation begins. That is, the control valve 8-7 opens, the water ejector 7 starts operating, sucks ozone under reduced pressure, dissolves it in water, and sends it to the point of use as highly concentrated ozone water. Here, the set temperature of the adsorbent is 115 qC higher than the temperature -3000 during the adsorption operation.
This is an ozone adsorption amount of about 1'2 of the ozone saturated adsorption amount at the temperature at which the adsorbent operates. The reason for increasing the temperature of the adsorbent is to remove ozone from the adsorbent and make it different, since the equilibrium adsorption amount of ozone in the adsorbent decreases. FIG. 4 shows the relationship between the ozone desorption time and the amount of ozone desorbed per unit time.

According to this, as shown in Fig. 2, in the conventional device, the amount of desorbed ozone rapidly decreased from the initial high amount of desorption to several 1% of the total amount of adsorbed ozone, but with the present invention, the amount of ozone desorbed was high from the beginning. of ozone is desorbed, and the desorption is maintained at a constant amount over time according to the conditions of use of the ozonated water. In the embodiment of the present invention, the detection sensor 9 detects the temperature reached in the adsorption/desorption tower and starts the ozone desorption operation, but other detection sensors detect the pressure due to the temperature increase in the adsorption/desorption tower. The same effect as described above can be obtained by detecting the pressure change and converting this pressure change into an electric signal.

As described above, according to the present invention, by setting the heating time of the adsorbent before the ozone removal operation and heating it,
It is possible to dissolve ozone at a high concentration of ~5 skin t% in water.

Therefore, this highly concentrated ozonated water promotes the reaction between ozone and the substance to be treated, so that ozone can be used effectively. It is also widely applied to other fields such as chemical plants. Furthermore, since ozone can be desorbed and desorbed efficiently, the amount of ozone leaked is reduced, the device can be made smaller, and equipment costs and operating costs can be reduced.

[Brief explanation of drawings]

Figure 1 shows a conventional example, where A is a configuration diagram of an ozone supply device, Figure 2 is a diagram showing the operating time of the equipment, and Figure 2 is a characteristic diagram showing the rate of ozone desorption per unit time. ,
Fig. 3 shows an apparatus for carrying out a method for supplying intermittent ozone according to an embodiment of the present invention, where A is a block diagram of the ozone supply apparatus, Fig. 4 is a diagram showing the operation time of the apparatus, and Fig. 4 is a diagram showing the operation time of the apparatus. It is a characteristic diagram showing the ratio of the amount of ozone desorption per unit time in the invention. 1... Ozone generator, 2... Oxygen supply source, 3...
Circulating blower, 4... Adsorption/desorption tower, 6... Heating source, 8-
1-8-7...Switching valve, 9...Detection sensor. In addition, in the figures, the same reference numerals indicate the same or corresponding parts. 1st
Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] 1. Ozone adsorption operation in which ozonized oxygen is generated from raw material oxygen using an ozone generator, ozone is adsorbed and stored from the ozonized oxygen in an absorption tower, and the oxygen after ozone adsorption is returned to the ozone generator. and an intermittent ozone supply method comprising an ozone desorption operation in which ozone is desorbed and desorbed by vacuum suction from the adsorption/desorption tower, wherein the adsorption tower is cooled during the ozone adsorption operation, and after the ozone adsorption operation is finished, the ozone is desorbed and desorbed. An intermittent ozone supply method characterized by starting the ozone desorption operation after heating the adsorbent in the tower to raise its temperature, and flowing warm brine into the adsorption and desorption tower during the ozone desorption operation. 2. The ozone desorption operation is started when the temperature of the adsorbent is detected to be equal to or higher than a reference temperature by a detection sensor provided to detect the temperature of the adsorbent. An intermittent ozone supply method according to claim 1. 3. A patent claim characterized in that the ozone desorption operation is started when a pressure detection sensor provided in the adsorption tower detects the pressure inside the adsorption tower to be equal to or higher than a reference pressure. The intermittent ozone supply method according to item 1.