JPH05221612A - Screening test of anode assembly - Google Patents

Abstract

PURPOSE:To carry out screening test of a cathode assembly in high reliability by increasing the pressure of a discharging field to a level nearly corresponding to the ratio of the imposed potential for test to the imposed potential for operation and performing the test in the state. CONSTITUTION:A number of cathode assemblies each composed of a cathode wire inserted into an insulating dielectric sheath are arranged in parallel and silent discharge electrons are released between the cathode and an anode. Ozone is generated by the collision of the electrons with oxygen molecules. The screening test of the cathode assembly of the ozonizer having the above construction is carried out, after being assembled nearly in the form of final product, by increasing the pressure of the discharge field to a level nearly corresponding to the ratio of the imposed potential for test to the imposed potential for operation. The cathode assembly having a dielectric strength falling below the lower limit of the strength is broken and removed by this treatment and replaced with a new one. An ozonizer having high reliability can be produced by this process.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ozone generator, and more particularly to a screening inspection method for a cathode assembly.

[0002]

2. Description of the Related Art Heretofore, this type of apparatus has been constructed with a large number of cathode assemblies, and for example, ozone output of 1000 g /
The number of hr devices reaches about 10,000, and when 500 devices of this specification are to be supplied annually, 500 × 10 ⁴ cathode assemblies will be used, and the annual allowable number of accidental devices will be 1%. The control level is 1 PPM, and it is very difficult to control parts at such a high level.

[0003]

SUMMARY OF THE INVENTION The object of the present invention is to eliminate the drawback of the above-mentioned prior art, that is, the requirement for an extremely high level of quality control standards, and to make a lower limit withstand voltage by an inspection section voltage higher than an operation section voltage. The purpose is to provide a method to set the control standard to a possible level by removing the cathode assembly in advance and replacing it with a new one.

[0004]

According to the present invention, instead of the super high quality control standard of the cathode assembly, the inspection withstanding voltage higher than the operating voltage is used to destroy and remove the one with the lower limit withstand voltage. It is a thing.

[0005]

[Examples] For example, when borosilicate glass is used as an insulating dielectric, the distribution is a normal distribution, the average withstand field strength is 38.9 kV / mm, and the standard deviation is 6.43 kV /
Assuming that the measured value is mm, the operation section electric field strength is 16 kV.
/ Mm and the screening electric field strength is 21.5 kV /
mm, the safety factor is 1.34 times, the removal ratio of the lower limit electric field strength is calculated as 0.35% = 3500PPM, and the lower limit is 3500 times the level of 1PPM which is the ultra high level quality control standard. If the deterioration of the characteristics during the service period is 3.4 kV / mm based on the average withstand electric field strength, the lower limit electric field strength is 2
1.5-3.4 = 18.1 kV / mm, safety factor is 1.
It is 13 times lower, which is a reasonable value for design.

On the other hand, the discharge power when the screening electric field strength is applied is actually measured to be proportional to the electric field strength ratio to the power of 5 to 5.5. Is too severe, and the temperature rise of the dielectric with respect to the cooling source gas is 4.3 to 5.0 times, which is a condition of reality separation.

Therefore, for the purpose of the screening inspection, a constant discharge current condition is required. This condition is a ratio of the inspection section voltage to the operation section voltage, and by increasing the inspection pressure (absolute pressure base), this screening inspection is performed. Are the conditions for implementing.

[0008]

The lower limit of the cathode assembly can be removed by increasing the inspection pressure and keeping the discharge current almost constant by multiplying the screening inspection section voltage with respect to the operation section voltage. It is possible to provide an ozone generator.

Claims (1)

[Claims] 1. A plurality of cathode assemblies, each of which is formed by inserting a cathode wire into an insulating dielectric sheath, are arranged in parallel, and silent discharge electrons are emitted between the cathode and the anode. In an ozone generator that generates ozone, a screening test is performed in a state in which the discharge field pressure is increased substantially in accordance with the ratio of the inspection applied voltage to the rotational applied voltage in a state that the cathode assembly is assembled as a product. A method of screening and inspecting a cathode assembly, which is capable of providing a highly reliable ozone generator by removing those which fall within the lower limit of withstand voltage strength.