Ten Stage Knudsen Gas Pump

Abstract

A Knudsen gas pump is driven by the thermal transpiration effect. In this study, a Knudsen gas pump was fabricated which is powered by using a thermoelectric module. By adding current to the thermoelectric module, each module’s ceramic plate is heated/cooled causing a temperature gradient when positioned properly across the nano-porous membranes. Thermal transpiration occurs, causing a pressure gradient across the channels of the membrane which then induces a gas flow across the membrane. During the study, each single pump was initially tested for pressure performance by powering the thermoelectric at 6 and 15 Watts. Loaded and unloaded flow rates were also tested for a single pump. Five and 10 pumps were then connected into series and the pressure performance was tested at 6 and 15 Watts. The flow rate under loaded and unloaded conditions was also tested. It has been demonstrated that the 10 stage series Knudsen pump creates a significantly larger pressure than a 5 stage series or a single stage Knudsen pump.