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ISSN Druckformat: 1948-2590
ISSN Online: 1948-2604
EXPERIMENTAL INVESTIGATION OF THERMOMOLECULAR PRESSURE DIFFERENCE ON A THIN PERMEABLE NON-ISOTHERMAL MEMBRANE THERMOMOLECULAR PUMP
ABSTRAKT
A thermomolecular pump (TMP) is a pump in which the flow of thermal transpiration is realized, namely, the gas flow in the channel under the temperature difference moves from cold to hot. In this paper, the results of an investigation of the characteristics of a laboratory sample of a TMP, operating at gas pressure in the range of 0.04 ≤ p0 ≤ 10 torr are presented. The Peltier element was used as a non-isothermal perforated TMP membrane. The temperature regime on the proposed membrane was investigated experimentally. Application of the Peltier element as a membrane of the TMP allowed the heating and cooling of the surfaces of the TMP membrane to be structurally overlapped and implementing the time-constant temperature difference on the membrane. The measured thermomolecular pressure difference (TPD) values (ΔpT ) in the pump operation regime in the closed TMP channel and approximation of these values using numerical computation of the TPD, allowed the true value of the temperature difference for the gas in the channels of the TMP membrane to be determined. The value of the gas temperature difference in the channels along the membrane thickness (ΔT) is lower than the measured temperature difference at the copper buses of the membrane (ΔTω) by approximately 40%. As is shown experimentally, the TPD value does not depend on the direction of the gas motion through the permeable non-uniformly heated TMP membrane, i.e., there is no gravitational component in the TPD value. The experimental investigation results for the development of a laboratory sample of a TMP operating at high gas pressure in the range of 3 ≤ p0 ≤ 750 torr are presented.