Reciprocating liq. column metering pump - has oscillating liq. and buffer liq. between piston drive diaphragm and valved diaphragm pump

摘要

The metering pump has a reciprocating column of liquid (6) whose motion controls the inlet and delivery volume of the product to be pumped. The column (6) is contained in a tube (1) which at one end terminates at a piston-operated flexible diaphragm (20) and at the other end at a hollow chamber (23) sub divided into two chambers (26, 25) by another flexible diaphragm (24). The column (6) is separated from each of the diaphragms by columns of a buffer liquid (12, 12a). The pump chamber (25) is alternately connected (27) to inlet and outlet lines (28, 29). The column (6) may be an opaque liquid whilst the buffer liquid (12, 12a) is transparent and non-aggressive. There may be photoelectric elements (9, 10, 9a, 10a) controlling the inlet and outlet valves (27).