JPH04104883A - Slime removing equipment with ozone aqueous solution - Google Patents

Abstract

PURPOSE:To remove slime in a water pipe with an optimum ozone aq. soln. minimized in metallic corrosion by regulating the flow rate in a water pipe system in accordance with the material of the water pipe. CONSTITUTION:When a valve 13 is closed and valves 11, 12, 15 are opened, water in a water tank 6 is sent to an ozone absorption tower 2 with a pump 9. Ozone is absorbed herein and the obtained ozone aq. soln. is sent to a water pipe system 4 through the valve 12 with a pump 10. Further since the valve 15 is opened, the ozone aq. soln. is separated into a heat exchanger 3 and a by-pass pipeline 21. It is passed through a plant pipeline 5 and returned to the water tank 6. Thereby slime in the water pipe systems 4, 5 and the heat exchanger 3 is removed. In this case, the pump 10 is selected to the volume capable of being pressurized and introduced at several atmospheres. In such a way, even when slime is present in the water pipe systems 4, 5, the flow velocity of the ozone aq. soln. is made high and the removal capacity of the ozone aq. soln. is held constant in the water pipe. Thus, slime is efficiently and uniformly removed.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a slime removal device using an ozone aqueous solution that removes slime in a water pipe by flowing the ozone aqueous solution into the water pipe. .

(Prior art) Microorganisms in the water often propagate and adhere to the inner walls of water pipes used in heat exchangers and wastewater treatment equipment in industrial plants, forming slime. As well as impeding the flow and reducing the efficiency of heat exchangers or wastewater treatment.

When water pipes are made of metal, corrosion occurs; therefore, with the recent increase in the scale of industrial plants and the shortage of high-quality industrial water, measures to prevent slime have become an important issue.

Conventionally, chlorine or chlorine-based agents have been widely used to prevent slime, but there are problems in its use, such as the fact that wastewater containing residual chlorine after use pollutes the environment and must be treated.

On the other hand, one of the inventors of the present invention considered that an aqueous ozone solution is effective in decomposing and removing slime, and that residual ozone after treatment self-decomposes and does not become a source of pollution. Patent application for method 1977-13
6186 (Special Publication No. 56-12181) and Patent Application No. 5
1-34197 (Tokuko Showa 5g-27997).

(Problem to be solved by the invention) However, the materials of water pipes used in industrial plants are not the same. For example, electrolytic copper is generally used for the internal piping of heat exchangers, whereas electrolytic copper is used for water pipes connecting equipment. Generally, mild steel is used, so if the ozone aqueous solution is flowed at the same flow rate, there is a problem that depending on the material, the pipe may corrode.

The present invention was made in consideration of the above problems, and is a slime stripping device using an ozone aqueous solution that can efficiently and uniformly remove slime in water pipes while minimizing corrosion of the pipes even if the pipes are made of different materials. is intended to provide.

[Structure of the invention]

(Means and effects for solving the problem) In order to achieve the above object, the present invention provides an apparatus for peeling off slime by feeding an aqueous ozone solution into a water pipe to which slime is attached. By flowing the ozone aqueous solution at an appropriate flow rate, this can be done efficiently without causing corrosion of the pipes.
Moreover, the slime can be peeled off evenly.

For example, if the material of the water pipe is mild steel 5S-41, which is the most widely used material for cooling water systems, it is better to treat it by increasing the flow rate of the ozone aqueous solution, both from the standpoint of uniform stripping of slime and from the standpoint of corrosion. It will be advantageous.

Furthermore, according to the inventor's experiments, in the case of electrolytic copper, which is widely used in heat exchangers, the flow rate of ozone aqueous solution is 1 m/sec.
c shows about 5 times the amount of corrosion compared to air, but 0.5 m
The results showed that the ozone aqueous solution resulted in less corrosion when the amount of corrosion reached approximately /see.

The results of these experiments are summarized in Table 1 (Industrial Water No. 33)
No. 5 (No. 5 removed from August 1986).

Margin below Therefore, in a slime removal device using an ozone aqueous solution, corrosion of the water pipes is taken into account by increasing the flow velocity in water pipes made of mild steel, and by installing bypass piping and lowering the flow velocity in heat exchangers using electrolytic copper. This enables efficient and uniform slime removal from water pipes.

(Example) An embodiment of the present invention is shown in FIG.

In Figure 1, 1 is an ozone generator, 2 is an ozone absorption tower that absorbs ozone into water and creates an ozone aqueous solution, 3 is a heat exchanger in a plant that is supposed to prevent slime, and 4 and 5 are also used to prevent slime. 6 is a water tank, and 7 is an ozone decomposition tower that decomposes and discharges excess ozone.

In a device configured as shown in FIG. 1, during normal plant operation, valves 13 and 14 are open and valve 11 is open.
．． 12.15 is closed. The water in the water tank 6 is sent to the water pipe 4 by the pump 9, returns to the water tank 6 through the heat exchanger 3 and the water pipe 5, and the water is circulated.

When removing slime from water pipe systems including heat exchangers,
When valve 13 is closed and valves 11.12.15 are opened,
The water in the water tank 6 is sent to the ozone absorption tower 2 by a pump 9, and the ozone aqueous solution that has absorbed ozone in this period is pumped to the ozone absorption tower 2.
0 is sent to the water pipe system 4 via the valve 12. Also, since the valve 15 is open, the ozone aqueous solution is diverted to the heat exchanger 3 and the bypass pipe 21, returns to the water tank 6 through the plant pipe 5, and the slime in the water pipe system 4, 5 and the heat exchanger 3 is thereby Peeling is performed.

In this case, the pump 10 is selected to have a capacity that allows pressurized injection at diffused pressure. In this way, even if there is slime in the water pipe system 4.5, the flow rate of the ozone aqueous solution will be high, the stripping ability of the ozone aqueous solution will be maintained constant within the water pipe, and the process will be carried out efficiently.
Moreover, uniform peeling of the slime is performed. In addition, the heat exchanger bypass piping 21 has a flow velocity of 0.5 m/s on the heat exchanger 3 side.
The size is selected so that it is about ee. This makes it possible to remove slime from a heat exchanger using electrolytic copper with high efficiency while minimizing metal corrosion.

Another embodiment of the invention is shown in FIG.

In Fig. 2, bypass piping is installed in addition to the heat exchanger using copper to adjust the flow rate of the ozone aqueous solution, and an electric control valve 23 is installed at the inlet of the heat exchanger to control the flow rate.

Furthermore, if the plant cannot be stopped, it is also possible to adopt a method of performing intermittent operation to the extent that the capacity of the heat exchanger is maintained.

〔Effect of the invention〕

As explained above, according to the present invention, the flow rate of the water pipe system can be adjusted according to the material of the water pipe, so slime in the water pipe can be removed using an optimal ozone aqueous solution that minimizes metal corrosion. becomes possible.

[Brief explanation of the drawing]

FIG. 1 is a system diagram showing one embodiment of the present invention, and FIG. 2 is a system diagram showing another embodiment of the invention. 1... Ozone generator 2... Ozone absorption tower 3.
・・Heat exchanger 4, 5・・Plant water pipe 6・
・・Water tank 7・・Ozone decomposition tower 8・Blowers 11 to 17・・Valve 9.10・・Pump 21・・Bypass piping 22・・Water pipe 23・・Electric control valve (8733) Agent Patent attorney Inomata Yoshiaki (and 1 other person) Figure 1

Claims (1)

[Claims] An ozone generator, an ozone absorption tower that absorbs ozone from the ozone generator into water and creates an ozone aqueous solution, a pump that sends the ozone aqueous solution to the water pipe system where slime is to be removed, and a water circulation path for normal system operation and slime removal. An ozone aqueous slime removal device equipped with valves for switching between operation and operation, characterized in that it is equipped with bypass piping or a regulating valve that controls the flow rate of a part of the water pipe system in which slime is to be removed during slime removal operation. Slime peeling device using aqueous solution.