Effect of pumping time on high vacuum system

One of the basic considerations in designing a high vacuum system is the time required to pump the container to a given pressure. The time range is usually from a few minutes to a few hours. However, in some cases, the required pumping time may be seconds or days. It is difficult to estimate the relationship between time and pressure by theoretical or experimental methods, since the rate of air release (or virtual leakage) on the inner surface of the vessel is uncertain, and the time and pressure of air release are related to the rate of air release.

The venting of a given material depends on the temperature, surface brightness, prior exposure to various atmospheres, and the method of cleaning. Even approximate estimation of exhaust time can be very difficult when venting is significant. The designer USES a relationship suitable for higher pressures to measure the pressure-time curve from atmospheric pressure to about 10-2 torr. The final (ultimate) pressure can sometimes be estimated according to the steady-state (long time) bleed data and the characteristics of the bleed device. The most interesting area is between 10 and 2Torr and the ultimate pressure.

Such as:

 

Compound molecular pump unit

Product Description:

The system adopts the type of compound molecular pump unit, which is a clean vacuum acquisition equipment assembled on the rack by various performance compound molecular pump, front air pump, separation valve, front pipeline, water break protector, molecular pump power supply, high vacuum detection system (compound vacuum gauge), control power supply, etc. Easy to install, easy to operate, easy to join, reliable performance, can be widely used in surface analysis, accelerator technology, semiconductor equipment, plasma technology, electrical vacuum device manufacturing and vacuum technology fields.

Technical parameters:

1. Ambient temperature: 5~32℃

2. Air relative humidity ≤ 80%

3. Operating voltage: 220V±10% 50~60HZ

4. Power: 1KW

5. System ultimate vacuum degree: 1.0×10-4Pa

6. Trp-24 front stage pump: Pumping rate: 6L/S

7. Fj-620 molecular pump: Pumping rate (to air) : 600L/S

8. Inlet flange: DN160LF outlet flange: KF40

9. Recommended starting pressure: < 100 Pa

10. Ultimate pressure: 6× 10-6pA

11. ZDF-III composite vacuum gauge: Regulatory model: ZJ-53B/ZJ-54D short wire thermocouple gauge

Measurement range: 400 ~ 1× 10-1 Pa

Measuring route: 2

Reaction time: < 3S

Control range: 100 ~ 1× 10-1 Pa

Control the number of roads: 4 can be extended to 8

Control mode: relay contact output, load capacity AC220V/3A (or DC28V/3A) non-inductive load

Power supply: 220V ± 10% 50Hz

Power consumption: 25 w

12. Bellows: KF40X1000

Vacuum solenoid baffle valve: KF40

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