JPH0663103U - Vacuum deaerator - Google Patents

Abstract

(57) [Summary] [Purpose] The LV of the raw water flowing down in the tower gradually decreases as it goes downward, making it easier to reach the equilibrium dissolved gas concentration, and at the same time, the raw water falls along the inner wall of the side trunk. Provided is a vacuum degassing device which solves the problem of short pass. [Structure] The shape of the vacuum degassing tower main body 1 filled with the packing material 3 is such that the side trunk portion 9 of the tower main body 1 is provided with a flared slope so that the lower cross-sectional area is larger than the upper cross-sectional area.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a vacuum degassing device that efficiently removes gases such as oxygen and carbon dioxide dissolved in raw water.

[0002]

[Prior art]

 Water for cleaning semiconductor wafers, pharmaceutical water, etc. does not substantially contain dissolved electrolytes, fine particles, colloidal substances, high molecular weight organic substances, exothermic substances, etc., but also dissolved gas that may promote the growth of microbes. , Especially pure water with as much dissolved oxygen as possible is needed. In the case of boiler water in a thermal power plant, if oxygen is dissolved in the water, pitting corrosion may occur on the boiler body or condensate pipe, and if carbon dioxide gas acts simultaneously, the two gases act separately. It is known to cause more harm than ever, and degassed water that removes dissolved gas in water as much as possible is essential. Several devices have been developed so far to remove dissolved gas in raw water.One of them has been to create a vacuum inside the pressure vessel, and to dissolve the dissolved gas in vacuum while the raw water is flowing. There is a vacuum deaeration device that sucks it out.

FIG. 2 is a schematic view showing an example of a conventional vacuum degassing apparatus, in which 20 is a vacuum degassing tower consisting of a pressure vessel, and 21 is an upper part in the vacuum degassing tower 20. Distributor of raw water, 22 is a packing material such as Raschig ring for finely dispersing the raw water supplied from the distributor 21, 23 is a vacuum generating means such as a vacuum pump, and 24 is flowing down in the vacuum degassing tower 20. A discharge pipe for letting out the degassed water to the outside of the tower, and 25 are storage tanks for storing the degassed water through the discharge pipe 24.

In this conventional example, the raw water containing the dissolved gas supplied from the distributor 21 is finely dispersed in the flowing down layer of the filler 22 and has a large surface area to enhance the gas-liquid contact effect. At this time, since the inside of the vacuum degassing tower 20 has been evacuated by the vacuum generating means 23, the dissolved gas in the raw water is separated from the raw water and is attached to the top of the vacuum degassing tower 20. It is discharged to the outside of the tower through 26. The degassed water that has flowed down while being degassed in the vacuum degassing tower 20 is stored in a lower storage tank 25 through a discharge pipe 24, and is sent from here to each destination by driving a pump or the like (not shown). . In such a vacuum degassing apparatus, the side body of the conventional vacuum degassing tower 20 has a straight body shape, and the upper cross-sectional area and the lower cross-sectional area are substantially equal.

[0005]

[Problems to be solved by the device]

 As described above, the side body portion of the conventional vacuum degassing tower has a straight body shape. Therefore, the linear flow velocity of the raw water in the tower (hereinafter referred to as LV) is always constant from the beginning to the end, and when the dissolved gas concentration becomes low, the gas-liquid contact time is extended and the liquid side is changed to the gas side. There was a drawback that it was not possible to promote the transfer of gas to the. That is, the raw water containing dissolved gas flowing down in the vacuum degassing tower has a lower concentration of dissolved gas as it falls to the lower part.Therefore, unless the gas-liquid contact time is extended to the lower part, the equilibrium dissolved gas Although the concentration cannot be reached easily, as described above, since the conventional vacuum degassing tower has a straight body shape, the LV of the raw water is always constant, which corresponds to the degree of vacuum in the lower part of the tower. The problem is that the equilibrium dissolved gas concentration is sent to the lower storage tank without reaching it.

Further, even if most of the raw water supplied through the distributor into the vacuum degassing tower flows down while being dispersed by the packing material layer, a part of the raw water falls along the inner wall of the side trunk part. . The raw water falling along the inner wall is not degassed as desired, which causes a so-called short path problem. Therefore, it is preferable that the vacuum degassing device has a structure in which the amount of water that falls along the inner wall of the side body part is small, but the side body part of the conventional vacuum degassing tower has a straight body shape as described above. As a result, the raw water that had propagated through the inner wall once flowed down to the bottom as it was, causing more short-pass problems, which was an obstacle to the removal of dissolved gas.

In view of this, the present invention makes the LV of the raw water flowing down in the vacuum degassing tower slower as it goes downward so that the equilibrium dissolved gas concentration can be easily reached, and at the same time, the raw water that falls down along the side body is dropped. It is an object of the present invention to provide a vacuum degassing device which reduces the amount of water and eliminates the problem of so-called short pass.

[0008]

[Means for Solving the Problems]

 The structure of the present invention for achieving the above-mentioned object will be described in detail. Raw water is supplied from the upper part of a vacuum degassing tower body composed of a pressure vessel filled with a packing material, and the raw water is supplied to the inside of the vacuum degassing tower body. The dissolved gas in the raw water is removed by the vacuum generating means while the water is flowing, and the degassing treatment is carried out in the vacuum degassing device that allows the water to flow out of the tower main body through the lower discharge pipe. The air degassing apparatus is characterized in that the air column main body is formed such that the lateral cross section of the tower main body is provided with a diverging slope so that the lower cross sectional area is larger than the upper cross sectional area.

In this way, the device of the present invention is provided with a flared slope on the side body of the vacuum degassing tower body, so that the LV of the raw water flowing down in the tower body becomes slower as it goes downward. In addition to reaching the equilibrium dissolved gas concentration, the raw water flowing down the inner wall of the side body is easily transferred to the packing material because the side body is inclined toward the end, which is a so-called short circuit. It is possible to solve the path problem.

[0010]

【Example】

 Hereinafter, a specific configuration of the vacuum degassing apparatus of the present invention will be described in detail with reference to the illustrated embodiment. FIG. 1 is a schematic cross-sectional view showing an example of a vacuum degassing apparatus according to the present invention, in which 1 denotes a vacuum degassing tower main body composed of a pressure vessel. Reference numeral 2 denotes a distributor arranged in the upper part of the vacuum degassing tower main body 1, and raw water containing dissolved gas is supplied into the vacuum degassing tower main body 1 via the distributor 2. 3 is a packing material such as Raschig ring filled in the vacuum degassing tower body 1, and the raw water flows down in the tower body 1 while being finely dispersed by the packing material 3. Reference numeral 4 denotes a vacuum generating means such as a vacuum pump, and the gas in the vacuum degassing tower body 1 is exhausted to the outside of the tower body 1 through the gas suction pipe 5 by the vacuum generating means 4. Reference numeral 6 denotes a discharge pipe for the degassed water that is connected to the bottom of the vacuum degassing tower main body 1. Through the discharge pipe 6, the degassed water is stored in a storage tank (not shown). In addition, in the figure, 7 is a vacuum gauge provided on the upper part of the vacuum degassing tower main body, and 8 is vacuum degassing in order to prevent the filler 3 such as Raschig ring from being discharged to the outside through the discharge pipe 6. It is a plate attached to the bottom of the tower body 1.

According to the present invention, in such a vacuum degassing apparatus, the shape of the vacuum degassing tower main body 1 is provided with a flared slope on the side body 9 so that the lower cross-sectional area is larger than the upper cross-sectional area. The diameter of the upper end plate 10 is naturally smaller than that of the lower end plate 11 due to the fact that the entire side trunk 9 is provided with a splayed slope. In this way, since the side body portion 9 of the vacuum degassing tower main body 1 has a divergent shape, the raw water containing the dissolved gas supplied from the distributor 2 into the vacuum degassing tower main body 1 is filled by the filler 3. The LV will gradually decrease as it flows downward while being finely dispersed. As a result, the gas-liquid contact time can be extended when the dissolved gas concentration becomes low, and it becomes easier to reach the equilibrium dissolved gas concentration at the vacuum degree and temperature. In addition, since the inner wall surface of the raw water flowing down along the side body 9 is inclined like a divergent shape, it becomes easier to reach the filling material 3 such as the Raschig ring, compared to the case of the straight body side body. It can prevent the short pass of raw water.

As a result of an experiment conducted by the present inventors, the inclination angle of the side body portion 9 of the vacuum degassing tower body 1 is within the range of 5 ° to 45 ° with respect to the vertical line, and the desired effect can be obtained. However, it is more preferably within the range of 10 ° to 35 °. If the inclination angle is 5 ° or less, the shape becomes closer to a straight body, and the same problem as in the conventional vacuum degassing tower occurs. In addition, if the inclination angle is 45 ° or more, there is a disadvantage that a large amount of cost is required to manufacture the tower body, although the deaeration effect is not so different.

Next, the dissolved oxygen concentration is the same in the present embodiment in which the side body portion 9 of the vacuum degassing tower main body 1 is provided with an inclination angle of 15 ° and in the conventional example in which the side body portion has a straight body shape. The results are shown when the treatment effects were compared using the above raw water.

[Table 1]

As is clear from Table 1, the concentration of dissolved oxygen in the degassed water treated by the vacuum degassing tower according to the present invention was reduced by 0.05 mgO per liter of raw water as compared with the conventional example.

[0015]

[Effect of device]

 As described above, the device of the present invention is characterized in that the side trunk of the vacuum degassing tower main body is provided with a divergent slope, and the LV of the raw water flowing down in the tower main body goes downward. Since it gradually decreases, the gas-liquid contact time becomes longer, making it easier to reach the equilibrium dissolved gas concentration corresponding to the vacuum degree and temperature in the lower part of the tower, and the raw water flowing down the inner wall of the side body part Since the body part is inclined in a divergent shape, it is more easily transmitted to the filler, and the so-called short path of raw water can be reduced compared to the case of a side body part with a straight body shape.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing an embodiment of a vacuum degassing apparatus of the present invention.

FIG. 2 is a schematic view showing an example of a conventional vacuum degassing apparatus.

[Explanation of symbols]

1: Vacuum degassing tower main body 2: Distributor 3: Packing material 4: Vacuum generating means 5: Gas suction pipe 6: Discharge pipe 7: Vacuum gauge 8: Eye plate 9: Side body part 10: Upper end plate 11: Lower end plate

Claims (1)

[Scope of utility model registration request] 1. Raw water is supplied from the upper part of a vacuum degassing tower main body composed of a pressure vessel filled with a filler, and the raw water is dissolved in the raw water by a vacuum generating means while flowing down in the vacuum degassing tower main body. In a vacuum degassing apparatus that removes gas and causes degassed water to flow out of the tower main body through a lower discharge pipe, the vacuum degassing tower main body is shaped such that the cross sectional area is lower than the upper cross sectional area. The vacuum degassing apparatus is characterized in that the side trunk of the tower body is provided with a splayed slope so that it becomes larger.