Suction muffler for a refrigeration compressor

Abstract

A suction muffler for a refrigeration compressor, comprising a hollow body defining at least one dampening chamber that carries a gas inlet duct and a gas outlet duct presenting an inlet opening and an outlet opening, for communicating the interior and the exterior of the dampening chamber, at least one of the gas inlet and gas outlet ducts presenting at least one closed end, one of the inlet and outlet openings being positioned at a certain distance from said closed end, smaller than the distance of said opening in relation to the other opening of the same duct and in a region of the latter presenting a minimum acoustic pressure for a determined frequency, the dimensioning of said duct and of the cross section of the first of said openings being achieved so as to minimize the gas pulsation noises inside the suction muffler.

1 . A suction muffler for a refrigeration compressor mounted within a shell, said suction muffler comprising a hollow body defining at least one dampening chamber that carries a gas inlet duct having an inlet opening external to the dampening chamber and an outlet opening in the interior of the dampening chamber and a gas outlet duct presenting an inlet opening in the interior of the dampening chamber and an outlet opening external to said dampening chamber, wherein at least one of the gas inlet duct and gas outlet duct presents at least one closed end one of the inlet and outlet openings being positioned at a certain distance from said closed end, along the respective duct, smaller than the distance of said opening in relation to the other opening of the same duct and in a region of the latter presenting a minimum acoustic pressure for a determined frequency, the dimensioning of said duct and of the cross section of the first of said openings being achieved so as to minimize the gas pulsation noises inside the suction muffler. 
   
   
       2 . The suction muffler, as set forth in  claim 1 , wherein the gas inlet duct has its inlet opening connected to a suction line of a refrigeration system to which the compressor is coupled. 
   
   
       3 . The suction muffler, as set forth in  claim 1 , wherein the gas outlet duct has its outlet opening in fluid communication with a suction orifice provided in a valve plate of the compressor. 
   
   
       4 . The suction muffler, as set forth in  claim 3 , wherein the outlet opening of the gas outlet duct is maintained in fluid communication with the suction orifice through another dampening chamber having another gas outlet duct presenting an inlet opening opened to the interior of said other dampening chamber and an outlet opening connected to the suction orifice. 
   
   
       5 . The suction muffler, as set forth in  claim 4 , wherein at least one of the gas inlet and gas outlet ducts in the other dampening chamber has at least one closed end, one of the inlet and outlet openings being positioned at a certain distance from said closed end, along the respective duct, smaller than the distance of said opening in relation to the other opening of the same duct and in a region of the latter-presenting a minimum acoustic pressure for a determined frequency, the dimensioning of said duct and of the cross section of the first of said openings being achieved in such a way as to minimize the gas pulsation noises in the interior of the suction muffler. 
   
   
       6 . The suction muffler, as set forth in  claim 1 , wherein the closed end is submitted to the same gas pressure reigning in said region of minimum acoustic pressure. 
   
   
       7 . The suction muffler, as set forth in  claim 6 , wherein the distance between the medium line of the first of said openings and the closed end of the gas duct is greater than half the diameter of said opening. 
   
   
       8 . The suction muffler, as set forth in  claim 7 , wherein the closed end is defined in a plane intercepted by the direction of the gas flow passing through the first of said openings of the gas duct. 
   
   
       9 . The suction muffler, as set forth in  claim 8 , wherein the closed end is defined in a plane parallel to the direction of the gas flow passing through the first of said openings of the gas duct. 
   
   
       10 . The suction muffler, as set forth in  claim 1 , wherein at least one closed end is defined by a wall portion of the hollow body. 
   
   
       11 . The suction muffler, as set forth in  claim 1 , wherein at least one closed end carries a cover. 
   
   
       12 . The suction muffler, as set forth in  claim 11 , wherein the cover is incorporated to the respective closed end.