Abstract: An apparatus for preparing a machining liquid of an electroerosion machine comprises a filter to which is supplied a concentrate flow and from which a permeate flow is drained off. The filter is constructed as a membrane filter, the clogging of which is prevented in that the concentrate flow direction is periodically reversed.

Abstract: An apparatus for preparing a machining liquid of an electroerosion machine comprises a filter, to which is supplied concentrate flow from a concentrate tank and from which is drained a permeate flow. In order to obtain a high machining liquid quality the filter is constituted by a membrane filter, which is backflushed with a backflushing frequency, which is a function of a parameter of the electroerosion process.

Abstract: An apparatus for preparing and cleaning a machining liquid of an electroerosion machine comprises a filter, to which a concentrate flow is supplied from a concentrate tank and from which a permeate flow is drained off. Over a considerably extended time the quality of the machining liquid is maintained within a desired quality range, because the filter is constructed as a membrane filter and a disposal container having a fleece filter is provided to which is supplied at least part of the concentrate flow from the membrane filter and from which the partial flow filtered through the fleece filter is returned to the concentrate tank.