Ulvac VD151, Инструкция по эксплуатации

Страница: 40 / 68

YK08-0028-DI-002-08
22
4.4 Gas Ballast Function
This product is installed with the Gas ballast function as standard. It is applicable to breathe in the
condensed gas such as the steam and solution vapor. Breathed condensed gas shall be liquefied
through the Compress process of the Pump, mixed with the Pump oil and then cycled mixed
together inside the Pump unit. This status brings you the same situation that you used the high
steam pressure oil that raises the ultimate pressure. It also shortens the life cycle of the Shaft seal
since the oil lubrication shall deteriorate.
If introduced the air or dry nitrogen through the Gas ballast valve just before the Pump
compression process, the condensed gas is not liquefied but exhausted with the air through the
Exhaust valve.
To use the Gas ballast, breathe in the air through the Gas ballast valve before sucking in the
condensed gas and operate the Pump around twenty minutes; this is because the “Gas ballast
effect” becomes larger as the Pump temperature is higher. Wait until the Pump temperature rises
around 65°C to open the Vacuum valve (Fig. 5) So as to operate the Pump. The “Gas ballast
effect” under low temperature shall be lower than the specified process performance.
Note further that keeping the Gas ballast valve open when not breathing in the condensed gas
shall cause the Pump oil splashing and power loss and further rise the ultimate pressure. You
have to note also that the condensed gas might remain in the Pump oil after you have exhausted
a lot of condensed gas or exhausted the condensed gas (air or gas that contains less water or
other steam that contaminates the oil) without opening the Gas ballast valve since the process
capacity of the condensed gas by the Gas ballast valve is limited.
In such a case, close the Vacuum valve, breathe in the air through the Gas ballast valve and idle
operate the Pump. Then the oil temperature shall rise up and be cleaned by means of the Gas
ballast effect. Keep on idle operating the Pump without opening the Gas ballast valve as far as the
specified ultimate pressure is attained. You need to replace the Pump oil if it was not cleaned after
operated long time.
WARNING
1) The Vacuum pump gets high temperature during operation. As
the Gas ballast valve also gets high temperature, be sure to wear
protective gear such as a pair of gloves.
2) Ensure to close the Gas ballast valve to start operating the
Pump.
The oil might jet out of the Gas ballast valve during the operation
around high pressure range.