Tumble dryer with a heat pump system

Abstract

A tumble dryer (1) comprising a heat pump system (22) and an air flow circuit (21) for circulation of an air flow. The air flow circuit (21) comprises a condenser (19), a drying drum (11), a fan arrangement (13), an air flow duct (18) and an evaporator (15). The air flow duct (18) comprises a constriction (16), arranged upstream the evaporator (15). The constriction (16) is provided with a plurality of openings (23), distributed across a cross section of the air flow duct (18), wherein the constriction (16) is adapted to create a pressure drop in the air flow that is circulated in the air flow duct (18), when the air flow flows from a first side A of the constriction (16) to a second side B of the constriction (16). The openings (23) in the constriction (16) are adapted to distribute the air flow across the cross section of the air flow duct (18).

1 . A tumble dryer comprising a heat pump system and an air flow circuit for circulation of an air flow, the air flow circuit comprising a condenser, a drying drum, a fan arrangement, an air flow duct and an evaporator, wherein the air flow duct comprises a constriction, with a plurality of openings, arranged upstream the evaporator. 
     
     
         2 . Tumble dryer according to  claim 1 , wherein the constriction is provided with a plurality of openings, distributed over a cross section of the air flow duct, and is adapted to create a pressure drop in the air flow that is circulated in the air flow duct, when the air flows from a first side of the constriction to a second side of the constriction, and wherein the openings in the constriction are adapted to distribute the air flow over a surface of the evaporator. 
     
     
         3 . Tumble dryer according to  claim 1 , wherein the openings constitute at least ⅓ of a surface of the constriction. 
     
     
         4 . Tumble dryer according to  claim 1 , wherein a distance between the constriction and the surface of the evaporator is between 0-300 mm. 
     
     
         5 . Tumble dryer according to  claim 1 , wherein the constriction is a perforated plate. 
     
     
         6 . Tumble dryer according to  claim 5 , wherein the perforated plate is a metal mesh. 
     
     
         7 . Tumble dryer according to  claim 1 , wherein the rotatable drum comprises a circular rear wall with air inlet openings and a radial cylindrical wall with air outlet openings. 
     
     
         8 . Tumble dryer according to  claim 7 , wherein a space outside the drum's cylindrical wall is configured as a duct leading to a filter. 
     
     
         9 . Tumble dryer according to  claim 7 , wherein a filter is placed below the drum. 
     
     
         10 . Tumble dryer according to  claim 4 , said distance being between 10 mm and 40 mm.