Danfoss A/s

Knud V Valbjorn

Niels P Graversen

Volker Spies

Christian Dyhr-Mikkelsen Poul

Poul O Meldgaard

A refrigeration system having compressor controls responsive to the heat load on the system. Each selected evaporator of the system has a thermostatic switch unit which includes an associated temperature sensor in proximity to the evaporator. The thermostatic switch unit has an operating range with ON and OFF threshold values and function to operate an electromagnetic valve which controls the refrigerant admitted to the evaporator. The heat load to which the compressor controls are responsive is derived from the accumulated ON and OFF times of the switch insert.

Control arrangement for a refrigeration apparatus

The expansion valve has an inlet connection fluidly connected to a main valve while the main valve is fluidly connected through an outlet connection to the inlet of the evaporator of a refrigeration system. The main valve has a housing that includes a main valve chamber and a valve seat for fluidly connecting the inlet connection to the main valve chamber and a valve member movable between an open position and blocking fluid flow through the valve seat from the inlet connection to the valve chamber. A pressure operated servo arrangement is disposed in the main valve chamber for controlling the movement of the valve element and opens to the pressure outlet of a pilot valve arrangement. The pilot valve arrangement is disposed in a branch path that opens to inlet connection and to the valve chamber downstream of the valve set for controlling the fluid pressure at the pressure outlet.

Servo-controlled expansion valve for a volatile fluid

The invention relates to a valve for volatile liquids such as an expansion valve for a refrigeration plant. Magnetic valves of this type have a plunger actuated closure member which controls a small throttle opening which functions to vaporize the cooling liquid. The valve action can be noisy and damping chambers have been provided for damping the movement of the plunger. As disclosed herein such a damping chamber is disposed in the flow path downstream from the throttle opening where a cooling vaporization occurs and the cooling vaporization is effective to minimize vaporization in the damping chamber which would otherwise reduce the effectiveness of the damping chamber.

Valve for volatile liquids, particularly expansion valve for

A pressure responsive switching device, particularly a pressostat or thermostat, comprises an actuating element (5) which is loaded in one direction by an operating element (1) at the pressure and in the other direction by a main spring (9) by way of a force transmission device (10). The latter has a physical quantity (P.sub.k) which is variable with the force transmitted by the operating element. In addition, there is a measured value generator (23) which, depending on this physical quantity, delivers an electric analogue signal (S). The force transmission device may comprise a compensating force producer (10) in the form of an expansion element (15) which is provided with a liquid-vapor filling and a heating device (21), by which the compensating force of the force of the operating element (1) is made to follow. In this way, the switching device can deliver an analogue signal (S) corresponding to the system pressure (P) by using the same operating element (1).

Pressure responsive switching device particularly pressostat or

The invention relates to a thermostatic valve regulating system having a central control unit for operating two or more remotely located valve operating units. The valve operating units are for heat transfer equipment such as radiators. The valve operating units have expansible chamber elements and associated valve operating rods. The central control unit has an adjustable temperature response expansible chamber element -TRECE) with a vapor-liquid filling. The central control unit also has a transmitting expansible chamber element (TECE) which is connected to all of the expansible chamber elements of the valve operating units with capillary tubing. The capillary tubing and the connected expansible chamber elements are filled with a liquid transmitting element. The temperature responsive TRECE is in series relation to TECE and expansion and recession thereof cause an opposite recession or expansion of TECE. The expansion and recession of TECE is transmitted via the transmitting liquid to each of the expansible chamber elements of the remotely located valve operating units. SU

Sensing and setting device for a regulator arrangement comprising a

The invention relates to a thermostatic regulator assembly which has the dual function of controlling both the heating and air conditioning equipment of a building. The assembly basically incorporates a first valve unit for controlling the flow of a heating fluid such as steam or hot water and a second valve unit for controlling the flow of air which in turn can control the regulator of a damper system of ducts which supply cooled air for air conditioning. The first valve unit is operative when it is open and the second valve unit is operative when it is closed. Thermostatic motor means operate the first and second valve units sequentially so that they are sequentially effective for first and second temperature ranges which correspond to heating and cooling condition requirements. The second valve unit may have a valve seat in the form of a nozzle and a closure member in the form of a baffle plate.

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Nordborg, Denmark

Knud V Valbjorn