In this application, the moisture from the filtrate receiver of a vacuum filter is collected and fed back into the system. If a system upset occurs, such as the failure of the filtrate pump, slugs of liquid can carry over into the vacuum system. Soft solids from the filter can also enter the vacuum system. In both cases, the liquid and soft solids will not damage the liquid ring vacuum pump, improving the overall reliability of the vacuum filtration system. A variety of seal liquids compatible with the process vapors may be selected in order to minimize contamination of gases extracted during the filtration process.