Additive dispensing system for a washing machine appliance

Abstract

An additive dispensing system and method for dispensing wash additive from an additive reservoir of a washing machine appliance is provided. The additive dispensing system includes a tank level sensor and a Venturi pump for drawing wash additive from the additive reservoir. The method includes measuring a level of wash additive in the additive reservoir using the tank level sensor and/or the viscosity of the wash additive, determining an additive dispense rate based at least in part on the level of wash additive and/or the viscosity of the wash additive, and selectively dispensing the flow of water through the Venturi pump based at least in part on the additive dispense rate to dispense a target volume of the wash additive.

What is claimed is: 
     
         1 . An additive dispensing system for a washing machine appliance, the additive dispensing system comprising:
 a bulk storage tank defining an additive reservoir for receiving a wash additive;   a tank level sensor for measuring a level of wash additive in the additive reservoir;   an aspirator assembly comprising a Venturi pump, a water supply conduit, and a suction line, the suction line fluidly coupling the Venturi pump and the additive reservoir such that the Venturi pump draws wash additive from the additive reservoir when a flow of water flows through the Venturi pump;   a water regulating valve operably coupled to the water supply conduit for selectively providing the flow of water through the Venturi pump of the aspirator assembly; and   a controller operably coupled to the tank level sensor and the water regulating valve, the controller being configured for:
 measuring the level of wash additive in the additive reservoir using the tank level sensor; 
 determining an additive dispense rate based at least in part on the level of wash additive in the additive reservoir; and 
 selectively dispensing the flow of water through the aspirator assembly based at least in part on the additive dispense rate to dispense a target volume of the wash additive. 
   
     
     
         2 . The additive dispensing system of  claim 1 , wherein determining the additive dispense rate comprises:
 obtaining the additive dispense rate from a lookup table or database that correlates the level of wash additive to the additive dispense rate.   
     
     
         3 . The additive dispensing system of  claim 1 , wherein the additive dispense rate is based at least in part on a viscosity of the wash additive, and wherein determining the additive dispense rate comprises:
 obtaining the additive dispense rate from a lookup table or database that correlates the level of wash additive and the viscosity of the wash additive to the additive dispense rate.   
     
     
         4 . The additive dispensing system of  claim 1 , wherein selectively dispensing the flow of water based at least in part on the additive dispense rate comprises:
 determining a dispense duration corresponding to an amount of time the water regulating valve should be open to dispense the target volume of the wash additive; and   opening the water regulating valve for the dispense duration.   
     
     
         5 . The additive dispensing system of  claim 4 , wherein determining the dispense duration comprises dividing the target volume by the additive dispense rate. 
     
     
         6 . The additive dispensing system of  claim 1 , wherein the controller is further configured for:
 determining a viscosity factor of the wash additive; and   determining a corrected dispense rate based at least in part on the additive dispense rate and the viscosity factor.   
     
     
         7 . The additive dispensing system of  claim 6 , wherein the viscosity factor of the wash additive is defined as a ratio of an actual viscosity of the wash additive over an average viscosity of a standard wash additive. 
     
     
         8 . The additive dispensing system of  claim 6 , wherein determining the viscosity factor of the wash additive comprises:
 receiving a user input regarding an actual viscosity of the wash additive supplied to the additive reservoir; and   obtaining the viscosity factor from the actual viscosity of wash additive supplied to the additive reservoir.   
     
     
         9 . The additive dispensing system of  claim 6 , wherein the tank level sensor is a multi-level sensor for measuring the level of wash additive, and wherein the controller is further configured for:
 measuring a pre-dispense additive level;   measuring a post-dispense additive level;   comparing the post-dispense additive level and the pre-dispense additive level; and   adjusting the viscosity factor of the wash additive for a subsequent wash cycle if a dispensed volume is different than the target volume.   
     
     
         10 . The additive dispensing system of  claim 9 , wherein the controller is further configured for generating an alert if the comparison of the post-dispense additive level and the pre-dispense additive level shows a difference between the dispensed volume and the target volume after adjusting the viscosity factor. 
     
     
         11 . The additive dispensing system of  claim 1 , wherein the tank level sensor is a single level sensor for determining whether the level of wash additive is below a predetermined level, and wherein the additive dispense rate is determined to be a fixed high rate if the level of wash additive is above the predetermined level and a fixed low rate if the level of wash additive is below the predetermined level. 
     
     
         12 . A method for dispensing wash additive from an additive reservoir using a Venturi pump fluidly coupled to the additive reservoir through a suction line such that the Venturi pump draws wash additive from the additive reservoir when a flow of water flows through the Venturi pump, the method comprising:
 measuring a level of wash additive in the additive reservoir using a tank level sensor;   determining an additive dispense rate based at least in part on the level of wash additive in the additive reservoir; and   selectively dispensing the flow of water through the Venturi pump based at least in part on the additive dispense rate to dispense a target volume of the wash additive.   
     
     
         13 . The method of  claim 12 , wherein determining the additive dispense rate comprises:
 obtaining the additive dispense rate from a lookup table or database that correlates the level of wash additive to the additive dispense rate.   
     
     
         14 . The method of  claim 12 , wherein the additive dispense rate is based at least in part on a viscosity of the wash additive, and wherein determining the additive dispense rate comprises:
 obtaining the additive dispense rate from a lookup table or database that correlates the level of wash additive and the viscosity of the wash additive to the additive dispense rate.   
     
     
         15 . The method of  claim 12 , wherein selectively dispensing the flow of water based at least in part on the additive dispense rate comprises:
 determining a dispense duration corresponding to an amount of time a water regulating valve should be open to dispense the target volume of the wash additive; and   opening the water regulating valve for the dispense duration.   
     
     
         16 . The method of  claim 15 , wherein determining the dispense duration comprises dividing the target volume by the additive dispense rate. 
     
     
         17 . The method of  claim 12 , further comprising:
 determining a viscosity factor of the wash additive; and   determining a corrected dispense rate based at least in part on the additive dispense rate and the viscosity factor.   
     
     
         18 . The method of  claim 17 , wherein determining the viscosity factor of the wash additive comprises:
 receiving a user input regarding an actual viscosity of the wash additive supplied to the additive reservoir; and   obtaining the viscosity factor from the actual viscosity of wash additive supplied to the additive reservoir.   
     
     
         19 . The method of  claim 12 , wherein the tank level sensor is a multi-level sensor for measuring the level of wash additive, the method further comprising:
 measuring a pre-dispense additive level;   measuring a post-dispense additive level;   comparing the post-dispense additive level and the pre-dispense additive level; and   adjusting the viscosity factor of the wash additive for a subsequent wash cycle if a dispensed volume is different than the target volume.   
     
     
         20 . The method of  claim 19 , further comprising:
 generating an alert if the comparison of the post-dispense additive level and the pre-dispense additive level shows a difference between the dispensed volume and the target volume after adjusting the viscosity factor.