JPH04278183A - Cooling tower - Google Patents

Abstract

PURPOSE:To prevent the breeding of bacteria in hot-water and improve heat exchanging efficiency by a method wherein the water evaporating unit of a cooling tower is formed of the film of hydrophobic fine porous hollow threads. CONSTITUTION:A water evaporating unit 8 is constituted of the film 1 of hydrophobic fine porous hollow threads and hot-water intaking port 2 as well as a hot-water outletting port 3, which are connected to the film 1, while hot-water is passed through said water evaporating unit 8 to evaporate one part of the hot-water and cool it. The film 1 of hydrophobic fine porous hollow threads is constituted of hydrophobia resin such as polyethylene, polypropylene, polysulfone, fluorine resin and the like which are provided with the outer diameter of 10-5000mum, the thickness of 5-1000mum, the porosity of 10-90% and the diameter of hole of 0.001-1mum. The diameter of hole is far smaller than bacteria and, therefore, bacteria in atmosphere can not pass the wall of the film and invade into the hot-water whereby the bacteria will never be breeded. On the other hand, the hot-water will never exude to the outside of the film 1 of hydrophobic fine porous hollow threads whereby the breeding of bacteria on the surface of the water evaporating unit 8 will never be caused. Furthermore, the constitution of the cooling tower is simple and heat exchanging efficiency is improved.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling tower, and more particularly, to a cooling tower that is free from bacterial contamination due to the scattering of hot water in which bacteria have grown into the atmosphere.

0002

[Prior Art] Cooling towers that have been provided in the past spray hot water that has been heat-exchanged by a refrigerator or the like onto a filling material, and then blow wind from a fan attached to blow air onto the filling material. The hot water is cooled by the latent heat of vaporization generated at this time, and then sent to a heat exchanger such as a refrigerator again.

[0003] However, in recent years, as concerns about health and comfortable living environments have increased, bacteria from the atmosphere can breed in the warm water of cooling towers, and these bacteria can be dispersed into the atmosphere along with the warm water, causing negative effects on the human body. This has become a serious problem, and major problems such as the one seen in the U.S. military disease outbreak have also occurred.

[0004] Conventionally, this problem has been solved by: (1) adding a sterilizing agent to the water in the cooling tower, (2) creating a structure that completely separates hot water from the atmosphere, and (2) using a sterilizing filling material in the cooling tower. Measures were taken, such as:

[0005]

[Problems to be Solved by the Invention] However, this method has the following problems.

1. Although the method of adding disinfectant to the water in a cooling tower kills bacteria, the scattering of the disinfectant poses a problem of adverse effects on the human body.

2. A method that completely separates hot water from the atmosphere not only complicates the structure of the cooling tower but also reduces heat exchange efficiency.

3. In the method of using a bactericidal filling material in the cooling tower, if the filling material is weakly bactericidal, the hot water that is in contact with it in the cooling tower for a short time will not be sufficiently sterilized, and if the filling material is strongly bactericidal, it will not be sterilized. The above-mentioned problem of scattering of the sterilizing components occurs due to the elution of the sterilizing components.

The present invention has been made in view of the above circumstances, and provides a cooling tower that can prevent bacterial contamination due to the scattering of hot water into the atmosphere in which bacteria have grown, with a simple structure and without the use of disinfectants. intended to provide.

0010

[Means for Solving the Problem] This problem is solved by evaporating a part of the hot water generated by heat exchange with a refrigerator, etc., and cooling the hot water using the latent heat of evaporation generated by the evaporation for circulation and reuse. This problem can be solved by providing a water evaporation section made of a microporous hollow fiber membrane, and cooling the hot water by passing hot water through the water evaporation section and evaporating a portion of the hot water.

[0011] The hydrophobic microporous hollow fiber membrane is made of a hydrophobic resin such as polyethylene, polypropylene, polysulfone, or fluororesin, and has an outer diameter of 10 to 5000 μm.
Film thickness 5-1000 μm, porosity 10-90%, pore diameter 0.
A thickness of 0.001 to 1 μm is desirable.

0012

[Operation] In the cooling tower of the present invention, the hot water cooled by the latent heat of vaporization and the air from the fan are separated through the hydrophobic microporous hollow fiber membrane, thereby preventing bacteria in the atmosphere from entering the hot water. Therefore, bacteria will not grow inside the cooling tower, and bacteria will not be dispersed into the air with hot water.

The cooling tower of the present invention passes hot water generated by a heat exchanger such as a refrigerator through a water evaporation section made of a hydrophobic microporous hollow fiber membrane, evaporates a part of the hot water, and uses the latent heat of evaporation generated at this time to evaporate the hot water. The system is configured to cool the water and return it to a heat exchanger such as a refrigerator.

[0014] The pores in the membrane wall of the hydrophobic microporous hollow fiber membrane used in the present invention have a much smaller pore diameter than bacteria, making it difficult for bacteria in the atmosphere to enter hot water through the membrane wall. Therefore, bacteria will not grow inside the hydrophobic microporous hollow fiber membrane. In addition, bacteria that are mixed in hot water from the beginning can be sterilized by injecting a disinfectant with weak bactericidal properties during hot water circulation, or by attaching it to a support or the like and inserting it during hot water circulation.

[0015] Since the hydrophobic microporous hollow fiber membrane used in the present invention is hydrophobic, the water pressure generally used is 3 kg/
cm2, the hot water inside the hydrophobic microporous hollow fiber membrane does not seep out to the outside, and therefore bacteria in the atmosphere do not grow on the surface of the hydrophobic microporous hollow fiber membrane.

[0016] In addition, since the hot water in the steam state is much smaller than the pore diameter of the microporous hollow fiber membrane, it can move freely on the membrane wall, and can be cooled directly by the latent heat of evaporation due to the evaporation of the hot water, increasing the heat exchange efficiency. In good condition.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the cooling tower of the present invention will be described below with reference to FIGS. 1 to 3. FIG. 1 is a diagram showing an embodiment of the cooling tower of the present invention, in which reference numeral 1 is a hydrophobic microporous hollow fiber membrane, 2 is a hot water intake, 3 is a hot water outlet, 4 is a fan, and 5 is a Potting club, 6
7 is an air intake port, 7 is an air outlet, and 8 is a water evaporation part.

As schematically shown in FIG. 2, the water evaporation section 8 connects the inlet and outlet of hot water to the hydrophobic microporous hollow fiber membrane 1, and evaporates water into the hydrophobic microporous hollow fiber membrane 1. By blowing hot water from a cooler, etc. through the hydrophobic microporous hollow fiber membrane, a portion of the hot water that passes through the membrane from the surface evaporates, and the latent heat of evaporation cools the hot water. ing. The water evaporation section 8 has a structure in which the surface area of the hydrophobic microporous hollow fiber membrane 1 is as large as possible in order to increase the cooling efficiency of hot water, and several thousand thin tube-shaped hydrophobic microporous hollow fiber membranes 1 are used in the water evaporation section 8. It is desirable to have a structure in which tens of thousands of pieces are lined up.

FIG. 3 illustrates a hydrophobic microporous hollow fiber membrane 1 suitable for the present invention. The hydrophobic microporous hollow fiber membrane 1 is made of a hydrophobic resin such as polyethylene, polypropylene, polysulfone, or fluororesin, and has an outer diameter of 10
~5000μm, film thickness 5~1000μm, porosity 10~
90%, and the pore diameter is 0.001 to 1 μm. The pores in the membrane wall of this hydrophobic microporous hollow fiber membrane 1 have a much smaller pore diameter than bacteria, and bacteria in the atmosphere cannot penetrate into the hot water through the membrane wall. Bacteria do not grow inside the microporous hollow fiber membrane. In addition, bacteria that are mixed in hot water from the beginning can be sterilized by injecting a disinfectant with weak bactericidal properties during hot water circulation, or by attaching it to a support or the like and inserting it during hot water circulation. In addition, since this hydrophobic microporous hollow fiber membrane is hydrophobic,
At the generally used water pressure of 3 kg/cm2, the hot water inside the hydrophobic microporous hollow fiber membrane does not ooze out to the outside, and therefore bacteria in the atmosphere do not breed on the surface of the hydrophobic microporous hollow fiber membrane. do not have.

[0020] The cooling tower according to this embodiment transfers hot water generated by heat exchange from a cooler etc. to the hot water intake port 2.
The air is passed through the multiple hydrophobic microporous hollow fiber membranes 1 of the water evaporation section 8 while rotating the fan 4 provided on the side of the water evaporation section 8 to apply air to the hydrophobic porous hollow fibers. The hot water in the membrane 1 is cooled by the latent heat of vaporization of the water, and the cooled water is taken out from the outlet 3 and returned to a heat exchanger such as a cooler.

Next, the effects of the present invention will be clarified by specific examples.

(Specific Example) A cooling tower device constructed in the same manner as shown in FIG. 1 was manufactured and its performance was investigated. As a hydrophobic microporous hollow fiber membrane, EHF-270T (manufactured by Mitsubishi Rayon, polyethylene hydrophobic microporous hollow fiber membrane) 4300
Three books (40 cm in length) were bundled together and potted at both ends with urethane resin. These were stacked at 5 cm intervals to produce a water evaporation section made of hydrophobic microporous hollow fiber membranes. A hot water inlet from a heat exchanger was attached to one end of this, a hot water outlet was attached to the other end, and hot water of 37° C. was fed into the hot water inlet side from the heat exchanger at a rate of 40 liters/min. Next, air at 32° C. and 60% RH was taken in from the air intake port using a blower fan and applied at 5 m/min to the water evaporation section made of a hydrophobic microporous hollow fiber membrane. As a result, water at 32°C was obtained from the hot water outlet of the water evaporation section.

[0023] Furthermore, as a result of sampling the circulating hot water at 24-hour intervals, measuring the number of viable bacteria, and examining changes in the number of bacteria in the warm water, no bacterial growth was observed in the warm water. .

[0024]

Effects of the Invention As explained above, in the cooling tower of the present invention, the water evaporation part that generates latent heat of vaporization is formed of a hydrophobic microporous hollow fiber membrane, so that bacteria in the atmosphere can It cannot pass through the membrane wall of the hollow fiber membrane, so bacteria in the air will not breed in the warm water. In addition, warm water does not seep out to the outside of the hydrophobic porous hollow fiber membrane, and bacteria do not grow on the surface of the water evaporation part. Furthermore, it can have a very simple structure, consisting only of a device for passing hot water through the hydrophobic microporous hollow fiber membrane and a fan. As a result, it is possible to construct a compact cooling tower that does not allow bacterial growth in the atmosphere to grow within the cooling tower, has good heat exchange efficiency, is free from noise caused by falling water droplets, and is free from corrosion caused by water.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing an embodiment of a cooling tower of the present invention.

FIG. 2 is a schematic side view showing a water evaporation section in the cooling tower of FIG. 1;

FIG. 3 is a perspective view illustrating a hydrophobic microporous hollow fiber membrane suitably used in the present invention.

[Explanation of symbols]

1 Hydrophobic microporous hollow fiber membrane 2 Hot water intake 3 Hot water outlet 4 Fan 5　　　　Potting Department 6 Air intake 7 Air outlet 8 Water evaporation section

Claims (2)

[Claims] Claim 1: A cooling tower that evaporates a portion of hot water generated by heat exchange in a refrigerator, etc., cools the hot water using the latent heat of vaporization generated by the evaporation, and recycles and reuses the water, comprising a hydrophobic microporous hollow fiber membrane. Equipped with a water evaporation section,
A cooling tower that cools the hot water by passing the hot water through the water evaporation section and evaporating a part of the hot water. 2. The hydrophobic microporous hollow fiber membrane is made of a hydrophobic resin such as polyethylene, polypropylene, polysulfone, or fluororesin, and has an outer diameter of 10 to 5000 μm, a membrane thickness of 5 to 1000 μm, and a porosity of 10 to 90. %, pore size 0.0
2. The cooling tower according to claim 1, wherein the cooling tower has a diameter of 0.01 to 1 μm.