Abstract: A temperature control method includes obtaining, by a controller, a space temperature value, a space temperature set point, a discharge air temperature value, and a discharge air temperature set point. The method further includes determining a compressor speed using a first PI loop based on the space temperature set point and the space temperature value, and determining a supply fan speed using a second PI loop based on the discharge air temperature set point and the discharge air temperature value. The temperature control method further includes outputting a first control signal that controls the speed of a variable speed compressor based on the determination of whether the compressor speed is within the compressor operation range and a second control signal to control the speed of a variable speed supply fan based on the determination of whether the supply fan speed is within the supply fan operation range.

Abstract: A temperature control method includes obtaining, by a controller, a space temperature value, a space temperature set point, a discharge air temperature value, and a discharge air temperature set point. The method further includes determining a compressor speed using a first PI loop based on the space temperature set point and the space temperature value, and determining a supply fan speed using a second PI loop based on the discharge air temperature set point and the discharge air temperature value. The temperature control method further includes outputting a first control signal that controls the speed of a variable speed compressor based on the determination of whether the compressor speed is within the compressor operation range and a second control signal to control the speed of a variable speed supply fan based on the determination of whether the supply fan speed is within the supply fan operation range.

Abstract: A mobile stone crushing machine comprising a chassis on which is mounted a stone crushing unit and endless conveyor, a front end of which is adapted to collect stones from the ground as the machine is advanced over the ground, and from which the stones are continuously discharged into a stone crushing unit, characterized in that the stone crushing unit includes two crushing zones, each of which incorporates at least one crushing roller, so arranged that the stones to be crushed first pass through a nip associated with the roller at the first zone and on discharge from this nip the partially crushed stones and other matter then pass through a nip associated with the roller at the other zone. Preferably, the two crushing zones are arranged one above the other and each incorporates a pair of crushing rollers, one of which is rotatable about a fixed axis and driven and the other of which is supported upon a pair of trailing swing arms.