LEYBOLD RUVAC WH 2500, Инструкция по установке и эксплуатации

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Description
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130001398_002_C0 - 09/2016 - © Leybold
1.3.1 Maximum Pressure Difference
The maximum differential pressure at which the RUVAC can be operated at is
limited by two factors:
1. The installed motor power
2. The thermal limitations of the pump
The installed motor power must not be exceeded by more than a few min-
utes, which results in a fixed limit in differential pressure.
The thermal limits of the RUVAC can be exceeded for a limited time if this is
followed by a period of time that allows it to recover at a rather low pressure.
The percentage of time within a repeating cycle for which the RUVAC is oper-
ated at high differential pressure is called the duty cycle.
If the duty cycle is for example 25 %, the pump runs at high differential pres-
sure for a time period of 1 minute followed by a time period 3 minutes at a
discharge pressure of less than 1 mbar. If a cycle time of 40 minutes is
exceeded, the pump has to be considered in continuous operation.
Further factors can influence the maximum differential pressure as for exam-
ple the pump ratio, the rotational speed of the RUVAC, the gas intake tem-
perature, the ambient temperature and the gas type.
The pump ratio is equal to the effective compression ratio described in
Section 4.1
In general will a lower pump ratio result in a higher allowable differential pres-
sure.
The tables above give the maximum allowable differential pressures for the
RUVAC WH depending on pump ratio and duty cycle.
The given values are valid for air with a maximum intake temperature of
40 °C and an ambient temperature not exceeding 40 °C.