Abstract: A horizontal separator for separating impurities from geothermal steam or the like is provided which includes a pair of drip or drain legs for accommodating the separated fluid portion containing the impurities. To maintain the temperature of the drain legs sufficiently high to prevent hardening of the impurities on the walls thereof, a portion of the steam continuously flows into the drain leg with the separated impurities. In order to minimize venting of the steam supplied to the drain legs directly to atmosphere and consequent environmental problems, and also to improve the efficiency of operation of the separator, recycle lines are provided between the drain legs and the inlet to the separator for recycling a portion of the steam. At the inlet, this recycled steam is drawn into the separator by way of an ejector-type recycle pump.

Abstract: An apparatus and method is provided for venting high pressure gas to a lower pressure region with a minimum of noise. A high pressure vent valve controls egress from a high pressure gas source. In order to limit the generation of noise downstream of the vent valve, at least one control orifice is provided which is configured to have a flow velocity through a throat section thereof of the speed of sound, and with a pressure downstream of the throat being the same as the throat pressure. In this manner, the pressure is reduced by about half at each control orifice, with no or little noise generation. Downstream of these sonic velocity control orifices, sound attenuating means including radially extended passages lined with sound-baffling structure are provided to reduce any residual noise in the flowing gas as it passes into the region of lower pressure.