JPS62226801A - Method for dissolving ozone - Google Patents

Abstract

PURPOSE:To dissolve ozone with high ozone utilization efficiency by sending a suspension contg. fine gas bubbles contg. ozone under pressure to a pressure holding vessel, and storing the suspension in the vessel for specified time. CONSTITUTION:A soln. such as water is spouted from the central nozzle part 3a of a suspension producing nozzle 3 by a high-pressure liq. feeder 1 at the velocity of >=about 10m/sec. Meanwhile, oxygen contg. ozone is supplied from an ozonizer 2 under a high pressure of about 1 atm gage to a concentric peripheral nozzle part 3b of the nozzle 3 having <=about 0.5mm clearance between the parts. Consequently, the suspension contg. bubbles of oxygen contg. ozone having <=about 0.5mm, preferably <=0.3mm, diameter is formed, and sent to a suspension vessel 4. The obtained suspension is then sent under pressure to the pressure holding vessel 10 by a centrifugal pump 5 from the suspension vessel 4 through a check valve 9, and the suspension is retained under pressure for about 3-5min. The undissolved ozone and oxygen are thus separated, and then an ozone soln. is obtained with the high ozone utilization efficiency of >=about 70%.

Description

DETAILED DESCRIPTION OF THE INVENTION r Industrial Application Field 1 The present invention relates to an ozone dissolution method for dissolving ozone in a solution such as water.

rPrior Art Recently, ozone sterilization treatment, bleaching treatment, etc., which are free from residual toxicity, have been attracting attention. Since gaseous ozone is complicated to handle, ozone solutions are used for these ozone treatments, or when the object to be treated is a liquid, a method of dissolving ozone directly into the object is commonly used. .

Conventionally, the most efficient method for this type of ozone dissolution was to place a diffuser plate at the bottom of the solution tank to diffuse ozone-containing gas, or to use a static mixer. .

``Problems to be Solved by the Invention'' - However, with conventional methods of this type that use a diffuser plate or a static mixer, even when conditions such as liquid temperature and atmospheric pressure are optimal, the dissolution efficiency is low and the actual measurement results are low. The results showed that the ozone utilization efficiency could not exceed 30%.

Therefore, the present invention was made to solve the above-mentioned drawbacks, and an object of the present invention is to provide an ozone dissolution method that dramatically improves ozone utilization efficiency.

Means for Solving Problems J In accordance with the above-mentioned object, the structure of the present invention, which is summarized in the above-mentioned claims, is intended to solve the above-mentioned problems by dispersing ozone-containing gas into fine particles of 0.5 mm or less. The bubbles are suspended in a solution such as water to form a bubble suspension, and the bubble suspension is supplied under pressure to a pressure holding tank using a centrifugal pump and stored in the pressure holding tank for a predetermined period of time. This method is characterized by the following technical measures.

``Effect J'' Therefore, the ozone dissolution method of the present invention can be applied to ozone-containing gas (
Microbubbles of this gas (usually air or oxygen is used as the carrier for ozone) are suspended in the solution and mix the required amount of ozone into the solution. At this time, if the gas bubbles containing ozone are large, the bubbles will aggregate in a short time and become large bubbles that will float to the surface.
If the diameter is less than 0.3 mm, preferably 0.3 mm or less, a so-called cloudy bubble suspension will result.

Then, this bubble suspension is pressurized and sent to a pressurized holding tank, or because ozone has a solubility about 10 times that of oxygen, which is a carrier gas, the ozone in the fine bubbles is The dissolution saturation point is reached in minutes, and undissolved ozone and carrier gas are separated in the upper part of the pressurized holding tank.

Embodiment J Next, the present invention will be described below with reference to an example of an apparatus shown in the accompanying drawings.

In the figure, reference numeral 2 denotes a generator for gas containing ozone, and although it is not clearly shown in the figure, in this embodiment, a conventionally known ozone generator that uses oxygen as a raw material gas is used.

Reference numeral 1 denotes a high-pressure liquid supply device, and the discharge ports of this high-pressure liquid supply device 2 and the generator 1 are connected to a suspension production nozzle 3, respectively.

In the method of the present invention, first, the gas containing ozone is made into fine bubbles of 0.5 mm or less and suspended in a solution such as water using the suspension production nozzle 3 to form a bubble suspension. The suspension manufacturing nozzle 3 consists of a concentric two-fluid nozzle, and the suspension M!
It is located in I4.

That is, this suspension production nozzle 3 has a central nozzle part 3 that injects a jet liquid into the suspension tank 4 filled with the solution.
a, and a concentric peripheral nozzle part 3b having an ejection port on the outer periphery of the central nozzle part 3a. The discharge port of the navigation generator 2 is connected to. The solution filled in the suspension tank 4 is a high-pressure liquid supplied from the suspension production nozzle 3 in which a desired volume is retained, and water is used in this embodiment. .

Then, from the center nozzle part 3a, 10
The concentric peripheral nozzle part 3b is designed to eject jet liquid having a speed of 1/2 m/sec or more, and the concentric peripheral nozzle part 3b is designed to eject jet liquid with a gap of 0.5 mm or less from the central nozzle part 3a. A gas containing ozone is supplied to the nozzle part 3b from the whole fresh air 2 at a high pressure of 1 gauge pressure or higher.Then, the jet liquid from the central nozzle part 3a travels almost straight inside the suspension tank 4 and flows around the surrounding area. A strong vortex area is generated due to the friction with the solution liquid.Also, from the concentric peripheral nozzle part 3b, gas containing ozone is ejected in a thin film shape surrounding the jet liquid, and this gas containing ozone The bubbles are finely divided into fine bubbles by the countless eddy currents generated within the vortex area, and are fed and diffused together with the jet liquid, yielding a bubbly suspension liquid in which fine gas bubbles containing ozone are suspended.

In addition, when the jet liquid reaches a speed of 10 m/sec or more at the jetting start end, a strong /II flow area appears, and the smaller the gap between the outer periphery of the central nozzle part 3a and the inner periphery of the concentric peripheral nozzle part 3b, the more ( Practically, it is desirable that the gap is about 0.1 mm), and if this gap is set to 0.5 mm or more, the concentric peripheral nozzle part 3b
There may be a phenomenon in which a part of the ozone-containing gas ejected from the central nozzle part 3a becomes large bubbles and floats away from the vortex region. Pressurized liquid is injected, and the gap between the spout ports of the concentric peripheral nozzle part 3b is set to 0.5 mm or less, and when gas containing ozone is jetted into the concentric peripheral nozzle part 3b at a high pressure of 1 gauge pressure or higher, ozone is released. It has been found that a bubble suspension in which fine gas bubbles containing .

Next, in the method of the present invention, the bubble suspension obtained in the method L is supplied under pressure to a pressure holding tank using a centrifugal pump.

That is, the bubble suspension in which fine gas bubbles containing ozone are suspended is sent from the suspension M4 to the pressure holding tank IO by the centrifugal pump 5. Normally, when a liquid containing gas is pressurized with a centrifugal pump or transferred through a pipe, it is known that air blockage or cavitation occurs and the operation becomes impossible, but bubble suspensions have small bubble diameters. The suspended state lasts longer, and the bubble diameter is 0.5 mm or less, preferably 0.3 mm.
mm or less, the bubble suspension flowing in from the inlet 6 of the generally known centrifugal pump 5 is subjected to a strong stirring force within the centrifugal pump 5, and the bubbles are transferred to the outflow lower side without agglomeration of the bubbles. It is possible to supply the material under pressure.

The bubble suspension sent to the pressure holding JfilO is stored for a predetermined period of time. This storage promotes the dissolution of ozone and degasses the carrier gas oxygen from the bubble suspension, and the pressurized bubble suspension is kept under pressure for a certain period of time (example (for 3-5 minutes)
It was extremely effective to store it. A specific example of this pressurization maintenance is carried out by force-feeding a bubble suspension from the centrifugal pump 5 into the pressure maintenance M2O via the check valve 9, and the speed regulator of the centrifugal pump 5 is controlled by a signal from the pressure sensor 12. 8 to change the rotational speed of the centrifugal pump 5 in accordance with the opening degree of the take-out valve 11.

In addition, in 1, 13 is an automatic discharge valve for the gas separated and floated above the pressure holding Nl 110, and 14 is a decomposition tank for undissolved ozone.

"Effects of the Invention" The method of the present invention is as described above. First, gas containing ozone is made into fine bubbles of 0.5 mm or more and suspended in a solution such as water to form a bubble suspension. The required amount of ozone can be mixed into the dissolution solution efficiently through gas-liquid contact, and this bubble suspension is supplied under pressure to a pressure holding tank using a centrifugal pump and stored for a predetermined period of time, improving dissolution efficiency. However, it is possible to provide an ozone dissolution method with dramatically improved efficiency compared to conventional methods.

By the way, according to the results of the experiment, oxygen containing 20,000 ρρm of ozone was supplied from the generator 2 to the concentric peripheral nozzle part 3b, water at 5 atm was supplied from the high-pressure liquid supply device 1 to the central nozzle part 3a, and suspended t&! In step 4, a bubble suspension of fine bubbles with an average diameter of 0.2 mm is generated, and this bubble suspension is further pumped to the pressure holding tank 10 with a centrifugal pump 5 to maintain the pressure Nj1.
When the ozone solution was stored for 3 minutes at 2 gauge pressure in 0°C, an ozone solution of 17.7 ppm was obtained at a water temperature of 20 degrees Celsius.

In this case, the ozone utilization efficiency is 72%, which is 2% compared to the conventional method.
The efficiency was more than twice as high.

[Brief explanation of drawings]

The drawing is a partially sectional front view of an example of an apparatus for carrying out the method of the present invention. 1 ~ High pressure liquid supply device 2 ~ Generator 3 ~ Hanging l!
J flow production nozzle 3a ~ Mill center nozzle b ~ Concentric peripheral nozzle part 4 ~ Suspension tank 5 ~ Centrifugal pump
10 ~ Pressure holding tank b

Claims (1)

[Claims] Gas containing ozone is made into fine bubbles of 0.5 mm or less, suspended in a solution such as water to form a bubble suspension, and the bubble suspension is pumped into a pressure holding tank using a centrifugal pump. 1. A method for dissolving ozone, the method comprising: supplying the ozone under pressure to the pressure tank and storing the ozone in the pressure holding tank for a predetermined period of time.