Method for recovering refrigerant from a refrigeration equipment

Abstract

A method for recovering refrigerant from an external refrigeration equipment by a refrigerant recovery device includes recovering the refrigerant from the refrigeration equipment in a main recovering process. A small amount of heated refrigerant is recharged into the refrigeration equipment in a temporary refrigerant recharge process. An additional recovering process for emptying of a residual refrigerant from the refrigeration equipment is performed after finishing the temporary refrigerant recharge process.

1 . A method for recovering refrigerant from an external refrigeration equipment by a refrigerant recovery device, with the refrigerant of the external refrigeration equipment flowing from the refrigeration equipment through a refrigerant recovery path to a refrigerant tank of the recovery device, comprising:
 recovering the refrigerant from the refrigeration equipment in a main recovering process;   recharging a small amount of heated refrigerant into the refrigeration equipment in a temporary refrigerant recharge process; and   performing an additional recovering process for emptying of a residual refrigerant from the refrigeration equipment after finishing the temporary refrigerant recharge process.   
     
     
         2 . The method as claimed in  claim 1 , wherein, to perform the temporary refrigerant recharge process, the refrigerant recovery path is closed and a recharge path which connects the tank with the refrigeration equipment is opened. 
     
     
         3 . The method as claimed in  claim 2 , further comprising:
 establishing a connection between the refrigerant recovery device and the refrigeration equipment by switching on at least one valve in a valve block;   creating a low pressure at the inlet path of a compressor by switching on said compressor;   recovering the refrigerant from said refrigeration equipment to a refrigerant tank through the refrigerant recovery path comprising at least said valve block, said compressor and said refrigerant tank by the main recovering process;   switching off said compressor;   recharging the refrigerant from said refrigerant tank to said refrigeration equipment by keeping a heating element switched on through the refrigerant recharge path comprising at least said valve block and said refrigerant tank by the refrigerant recharge process;   switching off said heating element;   creating a low pressure at the inlet path of said compressor by switching on said compressor; and   emptying the rest of the refrigerant from said refrigeration equipment through said refrigerant recovery path by the additional recovering process.   
     
     
         4 . The method as claimed in  claim 1 , wherein the increase in temperature of the refrigerant by the temporary refrigerant recharge process causes change of state of the refrigerant recharged to said refrigeration equipment from liquid to gaseous. 
     
     
         5 . The method as claimed in  claim 4 , wherein the change in state of the refrigerant causes increase in pressure of the refrigerant recharged to said refrigeration equipment. 
     
     
         6 . The method as claimed in  claim 1 , wherein said temporary refrigerant recharge process increases the temperature inside the refrigeration equipment. 
     
     
         7 . The method as claimed in  claim 1 , wherein said temporary refrigerant recharge process changes the state of the refrigerant inside the refrigeration equipment. 
     
     
         8 . The method as claimed in  claim 7 , wherein said change in state of the refrigerant causes increase in pressure of the refrigerant in said refrigeration equipment. 
     
     
         9 . The method as claimed in  claim 7 , wherein performing said temporary refrigerant recharge process to said refrigeration equipment recovers additional refrigerant that is stuck in different parts of the refrigeration equipment. 
     
     
         10 . The method as claimed in  claim 1 , wherein the small amount of heated refrigerant is introduced into the refrigeration equipment in more than one pulse.