Lang Apparatebau Gmbh (lang)

Henkel Kommanditgesellschaft Auf Aktien

Herbert Hunklinger

Klaus Rutz

Albert Haberlander

The invention relates to a method for operating a dosing pump, the pump being driven by an asynchronous motor, comprising a drive which converts the motor revolutions into pump strokes of a defined stroke frequency. The pump strokes are comprised of a pump suction stroke and of a pump delivery stroke. Pump strokes are continuously carried out during a dosing phase. The aim of the invention is to provide a solution concerning a dosing pump having an asynchronous motor drive, a frequency converter thereto, and a control unit which interacts therewith in which the dosing behavior is improved during the operation of dosing pumps having an asynchronous motor drive. The invention provides that, with each pump stroke, an electric alternating voltage having a first frequency is applied to the asynchronous motor during the pump suction stroke, and that the same electric alternating voltage having a second frequency which is lower than that during the pump suction stroke is applied to said motor during the pump delivery stroke.

Regulation of the stroke frequency of a dosing pump

This invention provides a sealing mechanism for sealing the piston-cylinder unit of a reciprocating diaphragm pump to ensure that the piston-cylinder unit is permanently and reliably sealed while being simple to assemble. The invention further provides a piston-cylinder unit which has almost no play in the micrometer (&mgr;m) range, and which is sealed by hydrodynamically sealing a slot thereof.

Reciprocating diaphragm pump with packless piston-cylinder unit

A dosing pump for dosed liquid conveyance that includes a suction valve built into a suction tube coming out of a suction container, a pump chamber having a displacement volume that can be modified by means of a pumping member, a pressure valve leading to a dosing tube, a deaeration device arranged on the top end of the tube and comprising a return valve and a flow-actuated deaeration and bypass valve built into a deaeration valve having response characteristics dependent upon the state of aggregation of the liquid contained therein. The flow-activated deaeration and bypass valve is open when idle, only closing when pressure is raised in the presence of liquid in the valve, and is provided with a membrane. Faulty pump operation is substantially reduced when the membrane is connected to a remote closing member which closes the deaeration tube when the membrane is moved. A return valve is arranged between the membrane and the closing member.

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Ruhpolding, Germany

Herbert Hunklinger