JPS58166980A - Closed loop cooler - Google Patents

Abstract

PURPOSE:To eliminate the dissipation of ozone into the atomsphere and to prevent the troubles of sticking of living things by providing a heat exchanger to be cooled with circulating cooling water and providing a device for feeding ozone into the circulating water contg. bromide ion thereby constituting a closed loop cooler. CONSTITUTION:Bromide ion is fed from a storage tank 17 into a cooling water pipe 1 by a supply pump 18 prior to feeding of ozone, and when the concn, of bromide ion in the circulating cooling water attains several ppm, the pump 18 is stopped to stop supplying the bromide ion. An ozone generator 12 is then operated to form air contg. ozone in a high concn. and to feed to same through an ozone-air supply pipe 13 into a gas mixture 14 from which the air is fed as fine bubble into the bromide-contg. water fed from a pump 15 for mixing gases and is thereby dissolved. The ozone and the bromide ion react in this stage to form hypochlorite ion, by which living things are annihilated and the troubles of sticking of living things are eliminated.

Description

[Detailed description of the invention] This invention relates to a closed loop cooling device.

In a closed-loop cooling system, for example, after a heat exchanger is cooled by cooling water sent by a water pump, this cooling water is pumped into an air conditioning cooling tower, cooled, and then sent to a water pump again. It is configured so that water is sent to the heat exchanger.

In such a closed loop cooling system, a heat exchanger,
When cooling water pipes and air conditioning cooling towers are in use, microorganisms adhere and propagate on the walls, etc., resulting in a decrease in heat exchange capacity and blockage problems.

To prevent these disorders, fungicides are used.

As disinfectants, chlorine or chlorine-based agents, hydrogen peroxide, ozone, etc. are generally used. A closed-loop system has the disadvantage that when chlorine or chlorine-based chemicals are injected, chlorine ions that are injected together with these disinfectants or disinfectants accumulate and concentrate within the system, causing corrosion problems. On the other hand, the decomposition product of hydrogen peroxide is I! l! Because it is a sterilizing agent that consists of hydrogen and water, it is preferred as a sterilizing agent for closed-loop systems, but as is well known, its sterilizing effect is weaker than that of other sterilizing agents, and a large amount of injection is required, which poses a problem in the economics of operation. There is. In order to eliminate these drawbacks, the ozone injection method, which has greater bactericidal power and faster decomposition speed than these e-bacterial agents and does not leave anything other than oxygen after decomposition, is used as a closed-loop adhesion removal method. It is being

FIG. 1 is a system diagram showing a conventional closed-loop cooling system, and in the figure, III is a closed-loop cooling water pipe;
(2) C is the water tank connected to this cooling water pipe, (3) is the cooling water stored in this water tank, (4) is the water pump that sends this cooling water to the cooling water pipe +U, and (5) is The heat exchanger (6) installed in the cooling water pipe Il+ is the water sprinkling hole (7) t- connected to the cooling water pipe 1 on the outlet side of this heat exchanger.
(8) is a packed bed provided at the bottom of the water sprinkling hole (7), (91Fi is a blower that blows air to the bottom of this packed bed, and OI is an ozone generator 0 through a dryer 0υ.
A blower that sends air to 3, an ozone air pipe that leads ozonized air to an ozone generator 03 and a gas mixer Q4),
al is the gas mixing pump that sends water to the gas mixer (14), and αl19 is the gas mixer Q4). 4) is sent to the cooling water pipe Il+, and after being cooled in the heat exchanger (5) tank, it is sent to the water sprinkling hole (
Water is sprayed from the force and flows down the packed bed (8) filled with filler material. At this time, the cooling water flowing down comes into contact with the air blown by the blower (9)K, and a part of the cooling water evaporates into the blown air, thereby being cooled and stored in the water storage tank (2).

Water tank (2) cooling water + 3) tl Water supply pump (4) again
) is also sent to the active water pipe (1), forming a closed loop.

At this time, ozone generated by silent discharge is continuously or intermittently injected into the cooling water pipe (1).

The ozone used in this process is produced by compressing air with a blower a1, drying it in an air dryer 0υ until the dew point is below 140°C, and sending it to an ozone generator (I3). A portion of the oxygen in the air is ozonized by the silent discharge, becoming air containing high concentration of ozone.This air containing high concentration of ozone passes through the ozone air pipe 03 to the gas mixer α4.
(In this conventional example, the water works sector) is injected into the water sent from the gas mixing pump 05 as fine bubbles and dissolved therein. This ozonated water containing microbubbles is injected into the cooling water pipe (ill) through the ozonated water injection pipe (field) to kill microorganisms adhering to the wall of the cooling water pipe (1) and prevent problems. At this time, ozone can be continuously injected so that the effective residual ozone concentration is about 0.1 ppm, or high-concentration ozone can be injected over a relatively long period, that is, once a day, 5-10 pp per minute
m of effective residual ozonated air. 1 However, in such a configuration, when gas and liquid come into direct contact in the air conditioning cooling tower, most of the ozone dissolved in the cooling water is dissipated into the atmosphere because ozone is a *g-decomposable substance. However, the problem of causing ozone pollution was common.

In order to eliminate this emission of ozone into the atmosphere,
It is conceivable to use a disinfectant that can be soaked in water, for example, hypochlorite ions, but as explained above, in a closed loop system, disinfectants (hypochlorite ions) and chlorine ions are used inside the system. The drawback is that it accumulates and creates corrosion problems.

The present invention was made to solve the above-mentioned drawbacks of the conventional ones, and by providing a device for injecting ozone into circulating cooling water containing bromide ions, ozone does not diffuse into the atmosphere and has strong sterilizing power. An object of the present invention is to provide a closed-loop cooling device that has the following features and can thereby prevent biofouling damage.

Ozone reacts slowly with bromide ions in water, and the reaction products do not dissipate into the atmosphere and have strong bactericidal power. Moreover, when the reaction products decompose, they return to bromide ions, so ozone is used in circulating cooling water. The bromide ion concentration does not increase. The present invention has been made with attention to this point, and instead of continuously injecting bromine ions, circulating cooling water is pre-impregnated with bromine ions, and the reaction product generated by the reaction between ozone and bromide ions. This method eliminates the attachment of microorganisms in the entire closed loop system, including the air conditioning cooling tower, without dissipating disinfectants into the atmosphere and without accumulating or concentrating corrosive substances in the circulating cooling water. Can be removed.

FIG. 2 is a system diagram showing a closed loop cooling device according to an embodiment of the present invention. In the figure, (1) to QG indicate the same or corresponding parts as in FIG. 1, and the closed loop system and the microorganism removal device that generates ozone are constructed in the same manner as in FIG. 1. (171 is a storage tank for storing bromide ions, and a8 is a supply pump that injects bromide ions from this storage tank into the cooling water pipe fl).

In the cooling device configured as described above, before injecting ozone, bromide ions are injected from the storage tank Oη into the cooling water pipe (1) by the supply pump a8, so that the bromide ion concentration in the circulating cooling water is When it reaches ppm, the supply pump 08 is stopped to stop the supply of bromide ions. Next, the ozone generator a7J is operated to generate air containing A# degree ozone. This highly concentrated ozone-containing air is transported to the ozone air pipe 03.
The mixture is then sent to a gas mixer (water ejector in this example), where it is injected as microbubbles into the water containing bromide ions sent from the gas mixing pump q9, where it is dissolved. At this time, ozone and bromine ions react, producing hypobromite ions that kill living organisms and remove biofouling problems.

According to the results of a three-month experiment conducted to demonstrate the effects of the present invention, bromine ions were injected in advance to bring the bromine ion concentration to approximately 4 ppm in the circulating cooling water, and bromine ions were injected midway through the experiment period. If ozone is continuously injected at a concentration of 0.1 ppm relative to the amount of circulating cooling water without any Ions were detected by iodometry. Also, when ozone was intermittently injected once a day for 5 minutes at a concentration of 5 to 10 ppm, approximately 1 ppm of hypochlorite ions were detected as in the above case.

After completing this experiment, we investigated the state of adhesion and found that no adhesion was observed in the entire closed loop system including the air conditioning cooling tower (6). At this time, the cooling water at the outlet of the air conditioning cooling tower (6) was aerated and the ozone concentration remaining in the cooling water was measured, but no ozone was detected.

Figure 3 is a curve diagram comparing the emission rate of generated hypobromite ions, hypochlorite ions, and ozone into the gas phase at -7,5. It can be seen that the dissipation into the gas phase is extremely small, as is the case with hypochlorite-removed ions.

FIG. 4 is a curve diagram showing the lifetime of the generated hypobromite ion. From FIG. 4, it can be seen that the hypobromite ion once generated is relatively stable and has a lifespan of several days. Fifth
The figure is a curve diagram comparing the bactericidal power against general bacteria between the generated hypobromite ion, hypochlorite ion, and ozone.From the 5g5 diagram, hypobromite ion has inferior RI killing power to ozone. However, it is clear that it has a strong sterilizing power equal to or greater than that of hypochlorite ion. The present invention eliminates the adhesion and propagation of microorganisms using hypobromite ions, which do not emit into the atmosphere and have strong sterilizing power.

In addition, in the above embodiment, a case has been described in which dry air is used to generate ozone, but oxygen may be used instead of dry air. Since ozone can be injected in relatively long cycles, the ozone generator is configured to store ozone generated by silent discharge in low-temperature silica gel or carbon tetrachloride, and use the stored ozone. Also, the same effect as the above embodiment is achieved. Further, the configuration of the closed loop cooling device is not limited to that shown in the drawings.

As described above, according to the present invention, circulating cooling water is impregnated with bromine ions and ozone is injected in advance, and the reaction between the bromine ions and ozone generates hypobromite ions, so that sterilization is possible. There is no release of corrosive substances into the atmosphere, and there is no accumulation of corrosive substances in the cooling water.
It is effective in eliminating problems caused by microbial growth and adhesion in the entire closed loop system, including the 4ffi cooling tower.

[Brief explanation of the drawing]

Fig. 1 is a system diagram showing a conventional closed-loop cooling system, Fig. 2 is a system diagram showing a closed-loop cooling system according to an embodiment of the present invention, and Fig. 3 is a system diagram showing the flow of hypobromite ions into the atmosphere. Figure 4 is a curve diagram showing the emission rate, Figure 4 is a curve diagram showing the lifespan of hypobromite ions, and Figure 5 is a curve diagram showing a comparison of the bactericidal powers of various disinfectants. In each figure, the same reference numerals indicate the same or equivalent parts, +11
is cooling water pipe, (2) is water tank, (41ri water pump, (5) is heat exchanger, (6) is air adjustment cooling tower, (7)
is the watering hole, (8) is the packed bed, 00 is the dryer, 0 is the ozone generator, Q41 is the gas mixer, (+71 is the storage tank, a
8 is a supply pump. Agent Shin Kuzuno - (and 1 other person) Figure 2 Figure 3 Figure 6 1 庚 Nishi Ichilayer Rishinu A Roar (mq/,) 粁轻-Open! Jl
(hr)

Claims (1)

[Claims] In a closed-loop cooling system equipped with a heat exchanger that is efficiently cooled by ill Bikan cooling water, a device for injecting ozone into circulating cooling water containing bromide ions is provided. Closed loop cooling system. (2) The closed loop cooling system according to claim 1, further comprising a device for injecting bromide ions into the circulating cooling water. (3) A closed-loop cooling device according to claim 1 or 2, characterized in that ozone is injected continuously or intermittently.