Filter assembly for plate heat exchangers and method of cleaning a working medium in a plate heat exchanger

A method of cleaning a working medium in a closed-loop cycle comprising a plate heat exchanger including a plurality of heat exchanger plates arranged adjacent each other in a frame and having through-going holes for passage of the working medium and a cooling or heating fluid, respectively, the method comprising:

• providing a filter assembly including a proximal flange, a distal flange, at least one filter tube attached at respective ends to the proximal flange and the distal flange, respectively, at least one elongated filter element arranged in the at least one filter tube, a plurality of inlet holes arranged on a circumferential surface of the at least one filter tube, and at least one through-going outlet aperture arranged in the distal flange and in fluid communication with the interior of the at least one filter tube, wherein the filter assembly is dimensioned to fit into inlet or outlet ports of the plate heat exchanger, and wherein the plurality of inlet holes is arranged substantially in a longitudinal direction of the at least one filter tube and is located substantially in a same angular position with respect to a longitudinal axis of the at least one filter tube;
• inserting the filter assembly into an inlet or outlet port for the working medium in the plate heat exchanger, wherein the filter assembly is inserted such that the plurality of inlet holes is oriented in a substantially upward direction, opposite a direction of gravity;
• fastening the filter assembly on the frame of the plate heat exchanger, such that a fluid-tight seal is provided between the proximal flange and the inlet or outlet port;
• pumping the working medium in the closed-loop cycle, such that it passes into the filter assembly through the inlet holes on the surface of the at least one filter tube and out of the filter assembly through the at least one through-going aperture in the distal flange;
• wherein the filter assembly comprises a plurality of filter tubes;
• wherein the distal flange comprises a plurality of through-going outlet apertures, each through-going outlet aperture of the plurality of through-going outlet apertures being in fluid communication with the interior of a respective one of the plurality of filter tubes, and
• wherein the proximal flange comprises a plurality of through-going access holes, each through-going access hole of the plurality of through-going access holes being aligned with a respective one of the at least one filter tube.