JPH051440B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a blower having a shaft sealing device, and particularly to a blower suitable for a radioactive waste liquid drying and solidifying system.

[Prior art]

A conventional shaft seal device that is reliable is a mechanical seal that uses carbon and sliding members for the shaft seal portion, and uses water to prevent heat generation due to friction of the sliding portion.
However, water adds moisture to the dry solidification system, and if a failure occurs in the seal and water enters the system,
The drawback was that the dry solidification system could no longer be used.

[Purpose of the invention]

An object of the present invention is to provide a blower that continuously sends stable dry air to a radioactive waste liquid drying and solidifying system.

[Summary of the invention]

By using air film for the shaft seal,
The blower is designed to allow stable solidification system operation without using water.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIG. 1 is a blower, one side of which is connected to a granulated solidified material storage tank 5, and the other side connected to a storage tank ventilation and dehumidification tower 7. 2 is a shaft sealing device, which is connected to the blower 1 by a support base 6.
is firmly and removably fixed to the 4 is a controller connected to the air source 3 at one end and the shaft sealing device 2 at the other end. Next, the functions will be explained. The storage tank 5 is used for drying the granulated solidified material storage tank 5 for drying the radioactive waste liquid and turning it into a granulated solidified material.
The internal gas is sucked by blower 1 and transferred to storage tank ventilation dehumidification tower 7.
In the storage tank ventilation and dehumidification tower 7, which supplies pressurized air to the storage tank 5, moisture (moisture) in the air is removed by any method and circulated to the storage tank 5 to lower the internal humidity. In this way, the system continuously circulates the internal gas (gas containing radioactive particles) to dry the entire system. However, since this blower has a shaft that penetrates the air supply section, gas containing radioactive particles flows out from the penetration section, contaminating not only the blower but the entire building. Therefore, a shaft sealing device 2 is provided to seal this penetration part, but since it is a system for drying the storage tank 5, moisture cannot be introduced into the system from the sealing part. You can't even put water in it. For this reason, it is best to use dry gas such as dry air for sealing the shaft sealing device 2, and this sealing air is supplied from the air source 3. The controller 4 controls the pressure and humidity inside the drying and solidifying system so that seal air, which has a higher pressure and lower humidity than the inside of the drying and solidifying system, can be continuously supplied to the shaft sealing device 2.

The details of the shaft seal will be explained with reference to FIG.

In the figure, a bellows 12 is removably fixed between the casing 9 and the support base 6 with bolts. 13 is a case, which is inscribed with a float ring 14 through an arbitrary gap, and is removably bolted to the support base 6. A float ring 14 is mounted on the case 13 and is located between the seal ring 10 and the cover 16. A large number of springs 15 are provided on the circumference between the cover 16 and the float ring 14, one end of which is connected to the float ring 1.
Supported by 4. The cover 16 is fixed to the case 13 with bolts, and is inscribed with the seal ring 10 through a gap that does not allow contact.

Next, Figure 2 shows a cross section of the shaft seal, and Figure 3 shows a cross section of the case and float ring taken along line A-A in Figure 2.
The sealing mechanism of the shaft sealing device will be described in detail with reference to the drawings. Dry seal air flows in from the A part of the case 13, becomes equal pressure all around in the chamber between it and the float ring 14, flows in from the air supply opening of the float ring 14, and becomes a jet against the seal ring 10. It erupts. The reaction force at this time is balanced by a spring 15, and a suitable arbitrary air gap is formed between the seal ring 10 and the float ring 14 to prevent the float ring 14 and the seal ring 10 from coming into contact with each other. Further, the seal air ejected from this gap is ejected both inside the blower (that is, inside the drying and solidifying system) and outside the blower. At this time, by controlling the pressure of the sealing air to be higher than the pressure inside the drying and solidifying system, the air jetted into the drying and solidifying system will not flow backwards, making it possible to completely seal the shaft with this air jet. . Furthermore, by controlling the humidity of the seal air to be lower than the humidity within the drying and solidifying system, the drying process within the drying and solidifying system can be performed efficiently. Furthermore, since it is an air gap seal, a major feature is that no consumables are produced due to abrasion of the seal surface during operation.

〔Effect of the invention〕

1. By adopting an air seal shaft seal, the blower has high reliability and a stable drying system.

2 Even if the handling fluid and sealing fluid mix,
Since there is no leakage to the outside, there is no external contamination from the equipment. This reduces maintenance time. It becomes about 1/10.

3. Since there are no consumables, the entire system can be operated continuously, extending the maintenance cycle by three times.

[Brief explanation of the drawing]

FIG. 1 is a system diagram of an embodiment of the present invention, FIG. 2 is a cross-sectional view of the shaft seal portion of FIG. 1, and FIG. 3 is a cross-sectional view of the case and float ring taken along line AA of FIG. 2. 1...Blower, 2...Shaft sealing device, 3...Air source, 4
... Controller, 5... Granulated solidified material storage tank, 6... Support stand, 7... Storage tank ventilation and dehumidification tower, 9... Casing, 1
0... Seal ring, 11... O ring, 12... Bellow, 13... Case, 14... Float ring, 15
...Spring, 16...Cover, 17...Impeller, 18...
Shaft.

Claims (1)

[Scope of Claims] 1. A blower used in a radioactive waste liquid drying and solidifying system, comprising: an air film type shaft sealing device that uses dry air as a sealing fluid in a shaft sealing portion; a control device that controls the humidity of the drying air to be higher than the pressure and lower than the humidity in the drying and solidifying system, and the shaft sealing device is arranged along the axial direction of the shaft of the blower so as to cover the shaft of the blower. a seal ring located on the outer periphery of the seal ring, the seal ring having an annular protrusion on its outer periphery; an annular float ring incorporating a first channel for supplying the dry air; and a second channel provided on the outer periphery of the float ring for supplying the dry air to the first channel of the float ring. an annular dry air supply means incorporating an annular dry air supply means; and a ring-shaped dry air supply means provided between the dry air supply means and the casing of the blower, covering the outer periphery of the seal ring in the area between the two, and connecting the inside and outside of the blower. 1. A radioactive waste liquid drying and solidifying blower, characterized in that it is comprised of an axially expandable and isolating member.