METHOD AND SYSTEM FOR DELIVERING LIQUID REAGENTS TO PROCESSING VESSELS

摘要

A system for delivering a liquid reagent to a low pressure reactor in the vapor phase includes a source of the liquid reagent, a metering valve for measuring precise volumes of the liquid reagent and transporting those volumes to an expansion valve at a precisely controlled flow rate, and a vaporizing chamber. The expansion valve includes an adjustable orifice which is adjusted in response to pressure disturbances upstream of the expansion valve so as to decrease variations of the liquid flow rate to the expansion valve and thereby enhance uniformity of the vapor phase flow rate downstream of the expansion valve.