Abstract: A plate heat exchanger for use as an evaporator in a refrigerator including a compressor, a condenser, an expansion valve and the evaporator which cooperate to perform a refrigeration cycle. The plate heat exchanger comprises a plurality of plates stacked on each other to define chambers of a refrigerant and chambers of a medium to be cooled, a refrigerant introduction passage means extending through the plates and provided with orifices for delivering the refrigerant from the refrigerant introduction passage means to the refrigerant chambers, and a refrigerant stirring member for stirring the refrigerant supplied into the refrigerant introduction passage means in the form of a wet steam to make the refrigerant uniform.

Abstract: In an anti-clogging device, an opposed member is provided to be opposed to the grinding surface of a grinding wheel over a predetermined length with a fine space therebetween. During grinding, cutting eliminating liquid is fed into the fine space between the opposed member and the grinding surface from the end facing in the direction opposite to the rotating direction of the grinding wheel to prevent the grinding surface from being clogged with cuttings.