Dryer appliances and methods for diagnosing restrictions in dryer appliances

Abstract

Dryer appliances, methods for diagnosing restrictions in dryer appliance, and blower for dryer appliances are provided. A blower includes a blower fan and a scroll housing including an outer wall, the outer wall defining an interior, the blower fan rotatably mounted within the interior. The scroll housing includes a spiral portion, an outlet portion generally tangentially aligned with the spiral portion, and a cutoff wall extending from the outlet portion into the interior, the cutoff wall including a cutoff tip. The scroll housing further includes a tap aperture defined in the outer wall within a tap region, the tap region defined along a line between the cutoff tip and a joint location between the spiral portion and the outlet portion.

What is claimed is: 
     
         1 . A dryer appliance, comprising:
 a cabinet defining an interior;   a drum positioned within the interior, the drum defining a chamber for receipt of articles for drying;   an outlet assembly positioned within the interior, the outlet assembly comprising a vent duct, a blower, and an exhaust conduit, the blower comprising:
 a blower fan; 
 a scroll housing comprising an outer wall, the outer wall defining an interior, the blower fan rotatably mounted within the interior, the scroll housing comprising:
 a spiral portion; 
 an outlet portion generally tangentially aligned with the spiral portion; 
 a cutoff wall extending from the outlet portion into the interior, the cutoff wall comprising a cutoff tip; and 
 a tap aperture defined in the outer wall within a tap region, the tap region defined along a line between the cutoff tip and a joint location between the spiral portion and the outlet portion. 
 
   
     
     
         2 . The dryer appliance of  claim 1 , wherein the tap region is centered on a centerpoint of the line. 
     
     
         3 . The dryer appliance of  claim 1 , wherein the tap region has a long side of approximately 80% of a length of the line. 
     
     
         4 . The dryer appliance of  claim 1 , wherein the tap region has a short side of approximately 40% of a length of the line. 
     
     
         5 . The dryer appliance of  claim 1 , wherein the tap region is generally rectangular. 
     
     
         6 . The dryer appliance of  claim 1 , further comprising a pressure measurement assembly connected to the scroll housing. 
     
     
         7 . The dryer appliance of  claim 6 , wherein the pressure measurement assembly comprises a hose connected to the tap aperture. 
     
     
         8 . The dryer appliance of  claim 7 , wherein the pressure measurement assembly comprises a pressure sensor connected to the hose and in fluid communication with the tap aperture. 
     
     
         9 . A blower for a dryer appliance, the blower comprising:
 a blower fan;   a scroll housing comprising an outer wall, the outer wall defining an interior, the blower fan rotatably mounted within the interior, the scroll housing comprising:
 a spiral portion; 
 an outlet portion generally tangentially aligned with the spiral portion; 
 a cutoff wall extending from the outlet portion into the interior, the cutoff wall comprising a cutoff tip; and 
 a tap aperture defined in the outer wall within a tap region, the tap region defined along a line between the cutoff tip and a joint location between the spiral portion and the outlet portion. 
   
     
     
         10 . The blower of  claim 9 , wherein the tap region is centered on a centerpoint of the line, has a long side of approximately 80% of a length of the line, and has a short side of approximately 40% of a length of the line. 
     
     
         11 . The blower of  claim 9 , wherein the tap region is generally rectangular. 
     
     
         12 . The blower of  claim 9 , further comprising a pressure measurement assembly connected to the scroll housing. 
     
     
         13 . The blower of  claim 12 , wherein the pressure measurement assembly comprises a hose connected to the tap aperture. 
     
     
         14 . The blower of  claim 13 , wherein the pressure measurement assembly comprises a pressure sensor connected to the hose and in fluid communication with the tap aperture. 
     
     
         15 . A method for diagnosing a restriction in a dryer appliance, the method comprising:
 measuring an initial pressure value in a blower of the dryer appliance at a first predetermined time period after operation of the dryer appliance begins;   measuring a secondary pressure value in the blower of the dryer appliance during operation of the dryer appliance at a second predetermined time period after measuring the initial pressure value;   calculating a baseline pressure differential between the secondary pressure value and the initial pressure value;   measuring a tertiary pressure value in the blower of the dryer appliance at a third predetermined time period after measuring the second pressure value;   calculating a diagnostic pressure differential between the tertiary pressure value and the initial pressure value; and   transmitting a restriction signal when the diagnostic pressure differential is greater than the baseline pressure differential.   
     
     
         16 . The method of  claim 15 , wherein the steps of measuring a tertiary pressure value and calculating a diagnostic pressure differential are performed in a continuous loop during operation of the dryer appliance. 
     
     
         17 . The method of  claim 15 , wherein the restriction signal is a warning signal when the diagnostic pressure differential is greater than the baseline pressure differential within a first predetermined range, and wherein the restriction signal is a clear signal when the diagnostic pressure differential is greater than the baseline pressure differential within a second predetermined range greater than the first predetermined range. 
     
     
         18 . The method of  claim 15 , further comprising:
 measuring an install pressure value in the blower of the dryer appliance at the first predetermined time period after operation of the dryer appliance begins in an initial use;   measuring a subsequent initial pressure value in the blower of the dryer appliance at the first predetermined time period after operation of the dryer appliance begins in a subsequent use;   calculating a startup pressure differential between the subsequent pressure value and the install pressure value; and   transmitting a restriction signal when the startup pressure differential is above a predetermined differential level.   
     
     
         19 . The method of  claim 15 , wherein pressure values are taken from a tap aperture defined in an outer wall of a scroll housing of the blower, the tap aperture defined within a tap region, the tap region defined along a line between a cutoff tip and a joint location between a spiral portion and an outlet portion of the scroll housing.