JPS5932401B2 - ozone generator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ozone generator suitable for producing highly concentrated ozone water or the like safely and at low cost.

As is well known, ozone has the second highest oxidizing power after fluorine among practical substances, and the product after the reaction is harmless oxygen, so its use as an oxidizing agent, bleaching agent, etc. is extremely wide.

In particular, highly concentrated ozonated water has a fast reaction rate and is immeasurably effective as an oxidizing agent for selective oxidation reactions in chemical plants such as pulp bleaching.

A conventionally known apparatus for producing such ozone will be described below with reference to the drawings.

What is shown in FIG. 1 is a block diagram of an oxygen recycling ozone generator suitable for producing relatively highly concentrated ozone water.

In the figure, 1 is a raw material oxygen source, 2 is an ozone generator, 3 is a blower, and 4-1 and 4-2 are ozone adsorption/desorption devices filled with ozone adsorbent.

5 is a heat exchanger, 6 is an ozone desorption gas source, and 7 is a gas cooler.

Next, the operation will be explained.

When the oxygen introduced by the blower 3 passes through the ozone generator 2, a portion thereof is converted into ozone by silent discharge and becomes ozonized oxygen.

The ozonized oxygen that exits the ozone generator 2 is cooled by exchanging heat with the cooled oxygen that exits from the adsorption/desorption device 4-1 in the heat exchanger 5, and further cooled to a predetermined temperature in the gas cooler 7. It enters the ozone adsorption/desorption device 4-1 via the switching valve 8-1.

The adsorbent in the ozone adsorption/desorption device 4-1 selectively adsorbs ozone, and the remaining oxygen is returned to the blower 3 via the switching valve 8-3.

Oxygen consumed as ozone is replenished from the raw oxygen source 1.

While the adsorption/desorption device 4-1 is performing the ozone adsorption operation, the adsorption/desorption device 4-2 receives ozone desorption gas from the ozone desorption gas source 6 through the switching valve 8-8, An ozone desorption operation is performed in which the adsorbed ozone is desorbed and extracted as ozonized gas.

The desorbed ozone and the ozone desorbed gas are introduced into the gas-liquid contact device 9 through the switching valve 8-6, where the ozone is dissolved in water and sent to the point of use as ozone water.

When the adsorbent in the ozone adsorption/desorption device 4-1 adsorbs ozone to near saturation, the switching valve 8-1.8-6.8-8 closes.
The switching valves 12.8-4, [5, 8-7 are opened, and the adsorption/desorption device 4-1 performs the ozone desorption operation, and the adsorption/desorption device 4-2 performs the ozone adsorption operation.

By alternately using the adsorption/desorption devices 4-1 and 4-2 for ozone adsorption and ozone desorption operations as described above, they function as an ozone generator continuously.

In this way, in conventional ozone generators, when the ozone desorbed gas passes through the adsorbent cooled to a low temperature during ozone desorption, the water vapor contained in the adsorbent adsorbs to the adsorbent, causing a decrease in the ozone adsorption capacity and causing the ozone to be absorbed more than necessary. A large adsorption/desorption device must be provided.

Furthermore, in order to prevent this, it is necessary to sufficiently dry the desorbed gas, and a considerable amount of power is required to dry the gas.

In addition, the ozone concentration in ozonated water is controlled by the ozone concentration in the desorbed gas introduced into the gas-liquid contact device 9, and in order to produce high-concentration ozonated water (several 109/1 ten water or more), it is necessary to is 10wt% as shown in Figure 2.
(If air is used as the desorption gas) An ozone concentration of at least a certain level is required.

However, according to the conventional method, the ozone concentration in the desorbed gas is at most 10 wt%, making it difficult to produce highly concentrated ozone water.

It is also possible to obtain ozonized gas with a high concentration of ozone by heating the adsorption/desorption device and extremely reducing the amount of desorbed gas, but under normal pressure, ozonized gas of 20 wt% or more is unstable and decomposes rapidly. There is a high risk of an explosion.

Due to the above reasons, it has been difficult to safely and efficiently produce highly concentrated ozonated water using conventional ozone generators.

This invention was made in view of these points,
To provide an ozone generator capable of producing highly concentrated ozonated water safely and at low cost.

The principle of this invention shown in FIG. 3 will be explained below.

In the figure, the same reference numerals as in FIG. 1 indicate the same or corresponding parts, and 10 is a water ejector.

Next, the operation will be explained.

Ozonized oxygen, which is a part of the oxygen supplied from the ozone generator 2 converted into ozone, is cooled by the heat exchanger 5 and the gas cooler 7, and then passes through the switching valve 8-1 to the adsorption/desorption device 4-1. be introduced.

Ozone in ozonized oxygen is adsorbed by an adsorbent in the adsorption/desorption device 4-1, and the remaining oxygen is returned to the ozone generator 2 via the heat exchanger 5 and blower 3 via the switching valve 8-3. .

Oxygen consumed by being converted into ozone by the ozone generator is supplied from the raw material oxygen source 1.

While the adsorption/desorption device 4-1 is performing ozone adsorption operation,
The adsorption/desorption device 4-2 performs an ozone desorption operation, which will be described later.

When the adsorbent in the adsorption/desorption device 4-1 adsorbs ozone to near saturation, the switching valves 8-1, [3, 8-6 close, and the switching valves 8-2.8-5.8-7 open to perform the adsorption/desorption. The device 4-1 enters an ozone desorption operation, and the adsorption/desorption device 4-2 enters an ozone adsorption operation.

Ozone is desorbed by opening the switching valve 8-2 and sucking it under reduced pressure with the water ejector 10.The ozone is dispersed and dissolved in the water in the water ejector 10 where the ozone is desorbed without passing the desorbed gas and used as ozone water. sent to the location.

Further, the adsorption/desorption device 4-1, 4-2 alternately repeats the ozone adsorption operation and the ozone desorption operation using the switching valve to continuously produce ozonated water.

The principle of this invention is that ozone can be dispersed in water at a high concentration of 10 to 50 wt% by sucking it under reduced pressure and directly dispersing and dissolving it in water without using a desorption gas for desorption of ozone.

Therefore, the ozone water produced is 30 g/lon water to 200 g/ton water, as shown in the equilibrium diagram of the ozone water system in Figure 2.
Highly concentrated ozonated water of n water can be obtained continuously.

Further, ozonized gas with an ozone concentration of 10 to 50 wt% is extremely unstable under normal pressure, but the operation of this invention is -2
Since the process is carried out under a low pressure of 0 to -70 CIrLHg, the ozone density corresponds to an ozone concentration of 3 to 10 wt % under normal pressure, and there is no risk of ozone decomposition or explosion as described above.

Furthermore, since no desorption gas is used, there is no need for power for drying the desorption gas, pressure feeding, etc., and the cost of producing ozone water is reduced compared to conventional methods.

FIG. 4 shows an embodiment of the present invention, and the difference from FIG. 3 is that heat transfer bodies 12-1, 12
-2 is installed to cool the adsorption/desorption by flowing cooling fluid from the cold heat source 13 through the pump 15-1 and flow path switching valves 11-1 and 11-2 during ozone adsorption operation, and from the heat source 14 during ozone desorption operation. Pump 15-2 and flow path switching valve 1
1-3.

11-4, the heating fluid is caused to flow to heat the adsorption/desorption device.

When the temperature of the adsorbent is lowered, the amount of ozone adsorbed increases, and conversely, when the temperature of the adsorbent is raised, the amount of ozone adsorbed decreases.

Therefore, cooling during ozone adsorption requires a small amount of adsorbent (
A large amount of ozone is adsorbed by a small adsorption/desorption device), and by heating during ozone desorption, high concentration ozone is desorbed more easily and in a shorter time than an adsorbent without passing the desorption fluid and is supplied to the water ejector 10. become.

In addition, since the specific heat of the adsorbent is small and the power consumption for heating and cooling the adsorption/desorption device is small, the practical value of this invention is great.

Furthermore, when the cold heat source is produced using a refrigerator, it is expected that the increase in power can be suppressed by using waste heat from the condenser of the refrigerator as the heat source.

In addition, the ozone concentration in the gas phase in the adsorption/desorption device when transitioning from ozone adsorption to ozone desorption is at most 4wt% because it is ozonized oxygen sent from the ozone generator, and most of it is in the raw material gas. It is oxygen.

Therefore, immediately after the above operation is switched, the ozone concentration in the gas sucked into the water ejector 10 rapidly decreases, the ozone concentration in the water fluctuates greatly, and oxygen consumption increases more than necessary.

Such a runner-up is the switching valve 8-21゜8-22 from the adsorption/desorption device 4-1.
, 8-23 to connect the vacuum suction pump 16 and the ozone generator 2, and during the transition from ozone adsorption operation to ozone desorption operation, the vacuum suction pump 16 vacuum suctions the gas containing oxygen as a main component from the adsorption/desorption device. This can be easily solved by providing an oxygen recovery operation that recovers the oxygen.

As described above, this invention does not use desorption gas to desorb ozone, but instead suctions it under reduced pressure and directly disperses and dissolves it in water. Therefore, highly concentrated ozone water can be obtained continuously, and the desorption gas can be dried and pumped. Since no equal power is required, the cost of producing ozonated water is reduced compared to conventional methods.

Furthermore, since the operation is carried out under low pressure, there are various advantages such as eliminating the risk of ozone decomposition and explosion.

Further, according to the present invention, since the adsorption/desorption device is provided with a heat transfer body, ozone can be efficiently adsorbed and desorbed.

[Brief explanation of the drawing]

Figure 1 is a configuration diagram of a conventional ozone generator, Figure 2 is a curve diagram showing the relationship between ozone concentration in the gas phase and ozone concentration in water.
FIG. 3 is a block diagram showing one principle of the invention, and FIGS. 4 and 5 are block diagrams showing embodiments of the invention. In the figure, 1 is a raw material oxygen source, 2 is an ozone generator, 3 is a blower, 4-1.4-2.4-3 is an ozone adsorption/desorption device,
5 is a heat exchanger, 7 is a gas cooler, 11, 8-2,
[3, 8-4, 8-5, 8-6, 8-7 are fluid switching valves,
10 is a water ejector. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Scope of Claims] 1. An ozone generator that forms ozonized oxygen from raw material oxygen, and at least one adsorbent capable of adsorbing ozone from the ozonized oxygen formed by the ozone generator and desorbing the adsorbed ozone. It has a desorption device and a source oxygen source that supplies raw oxygen to the ozone generator, and returns the oxygen after ozone has been adsorbed by the adsorption/desorption device to the ozone generator, and removes ozone from the adsorption/desorption device. ozone adsorbed by the above-mentioned adsorption/desorption device.
A vacuum suction device that depressurizes and desorbs ozone at a pressure of 0 (crIlHg) or more and less than -20 [cIrLHg] and disperses the desorbed ozone in the fluid under the reduced pressure, and the adsorption/desorption device is provided with: An ozone generator characterized by comprising a heat transfer body through which a low-temperature fluid passes during ozone adsorption and a high-temperature fluid passes during ozone desorption. 2. The ozone generator according to claim 1, characterized in that a water ejector is used as the vacuum suction device.