JPS6038638B2 - gas cooling device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The so-called evaporative cooling device 3, which injects water 2 into a high temperature gas (air-containing air) 1 to appropriately cool it according to the purpose and uses the latent heat of evaporation, is conventionally well known. It can be roughly divided into those shown in Figures 1 and 2.

Note that 4 in the figure is a low-temperature gas. Figure 1 shows the upward flow type, and Figure 2 shows the downward flow type. Although the type shown in Figure 1 is common, the method shown in Figure 2 must be adopted due to the layout and configuration of related equipment. There is. In the downward flow type evaporative cooling device shown in Fig. 2, relatively large particles of injected water droplets fall downward, which tends to cause problems such as slurry formation and corrosion at the bottom of the device. Measure B is being implemented.

A: A method of positioning the nozzle 5 sufficiently high.

In this method, since there is a sufficient distance between the bottom and the nozzle, it is thought that the falling water droplets will evaporate to some extent before reaching the bottom, resulting in the amount of water reaching the bottom.

However, with this method, when plant conditions (especially gas amount) change (especially decrease), water droplets that would normally be difficult to fall will also fall.
Harmful effects are encouraged. Furthermore, since the nozzle is located high, the cooling tower becomes large, which causes an increase in costs. B. A method in which the entire or lower part of the tower of the cooling device has a double structure and heats up using exhaust gas.

The purpose of this method is to use the heat to evaporate even if water droplets fall, since the bottom is sufficiently heated.

However, this method is also subject to fluctuations in plant conditions (reduction in gas amount).
It was difficult to deal with it. Furthermore, it is difficult to evaporate a large amount of falling water droplets, and since it has a double structure, it has the drawback of increasing costs. The present invention has been proposed in order to solve the above-mentioned conventional drawbacks, and it is possible to predict the gas velocity inside the lower part of the cooling device in an upright or inclined type water injection evaporative gas cooling device in which high temperature gas to be cooled flows in from below. The height of the cooling device can be significantly reduced compared to conventional methods by providing a narrow part whose minimum gas amount to be obtained is greater than the natural falling speed of the expected maximum water droplet diameter, and a gas diffuser with a spread angle of 1 to 20 degrees. The purpose is to provide a gas cooling device that is possible.

Embodiments of the present invention will be explained below with reference to the drawings. FIG. A water injection gas cooling device 9 is shown (which may be in the form of a water injection gas cooling device 9), with cold gas 10 being discharged from the top. Reference numeral 11 denotes a mist water injection device, and a gas diffuser 12 is provided inside the device 11 below.

The dimension a of the gas diffuser 12 is the dimension that produces the gas velocity vg2, c,>c2, c,3 (approximately 10% of the total gas volume)
(dimensions sufficient to allow a corresponding amount of gas to pass through), when the spread angle b is 10 to 20o, and the spray water injection device 11 has dimensions d
are arranged so that they are at the optimum distance depending on the correlation between the crab mist level and the gas velocity, and the dimensions e and f are determined by the temperature of the high-temperature cooled gas 6 and the low-temperature gas 7, the gas amount, the water injection droplet diameter, etc. It can be demonstrated that a complete evaporative cooling effect can be obtained when That is, the gas velocity vg2 at the bottom of the gas diffuser 12 is selected to be the minimum amount of gas that can be expected, and the natural falling velocity of the maximum water droplet diameter (500
If the water droplet is about the size of a Buddha, the speed is larger than about 7 to 1 blood/s, for example, 13 m/s or more, so that harmful effects caused by falling water droplets can be avoided.

Also, even if water drops fall, if the diffuser is heated enough,
Evaporation is possible with the heat, and for this purpose, the gaps c and c2 are increased so that the amount of gas can be distributed between the internal dimension a of the diffuser section and the external gaps c, c2 at a ratio of about 9:1.

The dimensions c and c2 vary depending on the gas amount and column diameter, so it cannot be stated unconditionally and is not valid, but in a normal design, 9:
It is sufficient to use around 1 as an indicator. Also diffuser 1
The spread angle b of 2 should be such that the gas flow is not disturbed, and b = 10
It is necessary to keep it below ~2 pi.

Next, in Fig. 4, vgl: superficial gas velocity vf: sedimentation velocity of maximum droplet particle 13 V: gas velocity determined so that v material pg > vf pf Pg: gas density pf: spray liquid Given the droplet density, the largest droplet particles will not fall to the bottom of the cooling device.

However, it is assumed that vgl and Vg2 take the expected minimum values. By setting the diffuser gaps c and c2 to the above values, the lower part of the diffuser 12 and gas cooling device 9 is sufficiently heated by the high temperature gas passing through c and c2. 12 and/or the gas cooling device 9, it may re-evaporate.
There is no chance that droplets will fall below the main body (bottom) and cause an obstruction.

As explained in detail above, the present invention provides a gas diffuser inside the lower part of the cooling device, so a complete evaporative cooling effect can be obtained, and compared to the conventional method A, the nozzle position can be lowered. Reduce the size of the cooling tower to 1/5 of the subordinate size.
~1' nail lotus degree can be shortened.

[Brief explanation of drawings]

1 and 2 are longitudinal sectional views showing a conventional evaporative cooling device, FIG. 3 is a longitudinal sectional view of a gas cooling device showing an embodiment of the present invention, and FIG. 4 is a longitudinal sectional view of the diffuser in FIG. 3. FIG. Explanation of the main parts of the diagram, 6... High temperature cooled gas,
9...Gas cooling device, 11...Spray water injection device (cooling device), 12...Gas diffuser. Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] 1. In an upright or inclined water injection evaporative gas cooling system where high-temperature cooled gas flows in from below, there is a
A narrow part where the gas velocity is greater than the natural falling velocity of the expected maximum water droplet diameter at the minimum expected gas amount, and a divergence angle of 1
A gas cooling device characterized by having a gas diff user whose angle is 0° or more and 20° or less.