GB1466428A - Refrigerator system - Google Patents

Abstract

1466428 Refrigerating E FUNARO 8 May 1974 [8 May 1973] 20365/74 Heading F4H In a compression-condensation refrigeration system, the length of the refrigerant flow path through a capillary tube system is variable in response to changes detected in the temperature of the condenser 18. As shown, refrigerant passes from the condenser 18 and a receiver tank 19 to a regulating device 30, including a capillary flow path of variable length, from which it passes through fixed capillary tubes 28, arranged in parallel, through a syphon arrangement, Fig. 5 (not shown), to the evaporator 24. The regulating device 30 comprises a solid cylinder 35, Fig. 4, which has threaded end portions and a central section of smaller diameter and which is slidable in a tube 36 with precision fitting between the screw thread ridges and the inner surface of the tube. The tube 36 has a chamber B at one end and, at the other end, penetrates a wall of a fluid tight housing 42 containing an electromechanical device for moving the cylinder 35 along the tube 36. The chamber B and housing 42 are connected to branches of a pipe 20 leading from the bottom of the refrigerant receiver tank 19. The centre section of the tube 36 is provided with two rows of holes 37, the left row being covered by the left threaded portion of the cylinder 35 when the cylinder is moved to the right from the position shown, and is surrounded by a sleeve 38 having an outlet pipe 34. The electromechanical device comprises a motor 41 having a threaded output shaft 43 engaging an arm 44 which is secured to an extension of the cylinder 35 and to a potentiometer slider. The motor 41 is controlled by a temperature-sensitive element which detects the condenser temperature and which functions as one of the resistances of a Wheatstone bridge. The temperature-sensitive element has a negative resistance coefficient and the other bridge resistances comprise two fixed resistances and the variable potentiometer resistance. The bridge circuit is connected to a voltage amplifier connected to two triggers which are connected to relays for inverting the rotation of the motor 41, Fig. 6 (not shown).