Liquid supply systems

摘要

A liquid supply module includes one or more sets of bulk liquid containers each supplying a respective reservoir via a liquid supply line. The bulk liquid containers and reservoirs are vented above the highest liquid level in the system. A pump periodically removes a known volume of liquid from a reservoir which is replenished from a bulk liquid container. A sensor detects a liquid/air transition in the liquid supply line to the reservoir indicative of the exhaustion of liquid resupply from the bulk liquid container. An air vent solenoid valve in communication with the reservoir is closed when an empty bulk liquid container is replaced. Normal pump operation siphons liquid out of the bulk container after container replacement. A control system tracks pump iterations and calculates a number of executable iterations remaining before the reservoir runs dry. With a fresh bulk container in place, the air vent solenoid opens the reservoir air vent upon detection of an air/liquid transition allowing liquid to flow by gravity from the bulk container into the reservoir. A bulk liquid container lid sensor indicates whether a bulk liquid container is properly installed in the system. The liquid module is disposable in a sliding drawer, and can include unique mechanical keying means to insure each bulk liquid container fits in only one position in the liquid supply module.