JPS6031536B2 - Method for removing dust inside electrical equipment containers using liquefied gas - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for removing dust from an electrical equipment container using liquefied gas, and particularly to a method suitable for removing dust from a high-pressure electrical equipment container using a large liquefied gas.

Dust in various types of power equipment, such as power equipment using high-pressure sulfur hexafluoride gas as an insulating medium, has an adverse effect such as deterioration of insulation properties, and this effect becomes greater as the voltage becomes higher.

For this reason, measures such as assembling equipment in a dust-free room have traditionally been taken, but since power equipment is generally large in size and the dust-free room is correspondingly large, it is difficult to assemble the equipment economically. The burden is extremely heavy, and the work is greatly restricted and troublesome, for example, by maintaining a dust-free environment. These manufacturing problems become even more serious as devices become larger in size due to recent increases in capacity and voltage (for example, 500 KV devices). Furthermore, when on-site assembly is required, a simple dust-free room is created using a plastic greenhouse, but it is often difficult to obtain a satisfactory dust-free environment, and depending on the site, this method may not be possible. There are many cases where even the application of a bonito room is not possible. Therefore, there is a desire to provide a method that can make the inside of the equipment dust-free without using a dust-free chamber. The present invention has been made in response to the above-mentioned needs, and will now be described in detail with reference to the drawings.

In the present invention, gas that is liquefied by compression at a slight pressure lower than the withstand pressure of the equipment container or at a temperature slightly lower than room temperature is blown into the upper part of the equipment container, and by compressing or cooling the gas, the gas is liquefied into the equipment container. It is characterized by being liquefied in the process, and is discharged from the equipment along with the liquefied gas through the action of taking in dust in the container that occurs when the gas dews, that is, the action of condensing with the dust as a core, and the cleaning action of the flow of liquefied gas. The liquefied gas suitable for carrying out the present invention is, for example, R-114 (molecular formula ccIF2-ccIF2,
A vapor pressure of 1.87 k9/earth (absolute pressure) at a temperature of 220 qo is considered. The figure shows one embodiment of the present invention. In the figure, reference numeral 1 denotes a sealed container to be exposed to dust. For example, if this is a break-out switch, there may be a cut-off electrode or other parts not shown inside. It houses the appendages of.

2 is a gas ejection nozzle, 3 is a liquefied gas accumulated at the bottom of the container, 4 is a cooling pipe that dissipates the heat generated during liquefaction, and 5 is a filter that removes dust from the liquefied gas. It is connected to the bottom of the container using a connection port prepared in advance at the bottom or an existing connection port.

6 is a circulation pump, 7 is a vaporizer, and 8 is a filter for removing dust in the gas, which is connected to the gas jetting nozzle 2, and the jetting nozzle is a pre-prepared connection port or a lead-out port for a conducting wire, etc. Place it in a container to keep it airtight.

In this embodiment, the gas blown from the jet nozzle 2 is liquefied 3 and accumulated in the lower part of the container 1 together with dust due to the compressive force within the container caused by the low supply pressure due to the pressure resistance of the container by the circulation pump 6.

After the dust contained in this liquefied gas 3 is removed by the filter 5, it is vaporized and removed by the vaporizer 7 and filter 8 by the pump 6, and is ejected again as gas from the ejection nozzle 2. Repeat this process until the required number of dust particles is reached to complete the dust-free process. After the liquefied gas is discharged to the outside of the container 1, the liquefied gas remaining in the container is completely removed by, for example, vacuuming if necessary. For example, sulfur hexafluoride gas SF6, which is an insulating gas, is filled in the chamber. In this way, the inside of the container can be made dust-free without using any dust-free chamber.

Therefore, not only is there no need to impose any economic burden on constructing a dust-free room, but it is also possible to easily accommodate larger equipment. In addition, since the present invention uses a gas with low liquefaction pressure at room temperature, it is possible to easily create a dust-free room using simple equipment such as a pump, vaporizer, and filter. By transporting it to the site, it is possible to easily eliminate dust at the site. In addition, the pressure resistance of power equipment containers is said to be the lowest, 4k9/
Therefore, if you use a liquefied gas with a vapor pressure of 4 kg/or less at room temperature of 20 oo, the advantage is that it can be made dust-free without being affected by the pressure resistance of the equipment. be. Although the present invention has been described above, it goes without saying that the present invention is applicable to making equipment other than power equipment and other general containers dust-free.

In some cases, the cooling pipe can be omitted depending on the amount of heat generated, and the vaporizer can also be omitted by utilizing natural evaporation. Moreover, the compression force may not be sufficient with only the supply pressure of the circulation pump. In such a case, a separate compression pump may be provided. Furthermore, liquefaction by compression may be combined with liquefaction by cooling, or liquefaction by cooling alone may be used. As is clear from the above explanation, according to the present invention, it is possible to eliminate dust without using a dust-free chamber and without being influenced by the pressure resistance of a dust-free container, and in particular, it is possible to eliminate dust in large electric power equipment. It is highly effective when applied to dust-free.

[Brief explanation of the drawing]

The figure shows an embodiment of the present invention.

Claims (1)

[Claims] 1 Gas with a vapor pressure of 4 kg/cm^2 or less at room temperature is liquefied by lowering the pressure or sending it into a cooled container of electrical equipment, and then discharging it outside the container to trap dust due to dew condensation during liquefaction. and a method for removing dust in an electrical equipment container using liquefied gas, characterized in that dust in the container is removed by the cleaning action of the liquefied gas flow.