METHOD FOR DETERMINING THE LOAD QUANTITY IN A SPIN DRYER AND SPIN DRYER

• US 20080104860A1
• Filed: 11/05/2007
• Published: 05/08/2008
• Est. Priority Date: 11/06/2006
• Status: Active Grant

• Current Assignee: EGO Elektro-Gerã¤Tebau GmbH (EGO Blanc und Fischer & Company GmbH)
• Original Assignee: EGO Elektro-Gerã¤Tebau GmbH (EGO Blanc und Fischer & Company GmbH)
• Inventors: Schmidt, Kay, Muenzner, Rainer
• Granted Patent: US 8,112,902 B2
• Time in Patent Office: Days
• US Class Current: 34/427
• CPC Class Codes: D06F 2103/02 Characteristics of laundry or load
• CPC Class Codes: D06F 2103/04 Quantity, e.g. weight or variation of weight
• CPC Class Codes: D06F 2103/08 Humidity
• CPC Class Codes: D06F 2103/34 Humidity
• CPC Class Codes: D06F 2105/52 Changing sequence of operational steps; Carrying out additional operational steps; Modifying operational steps, e.g. by extending duration of steps
• CPC Class Codes: D06F 2105/58 Indications or alarms to the control system or to the user
• CPC Class Codes: D06F 34/18 Condition of the laundry, e.g. nature or weight

Abstract

A spin or tumble dryer having an air outlet with a moisture sensor is connected to a controller. The moisture sensor determines and stored the measured absolute atmospheric humidity values in the air outlet during operation. Specific characteristic values of the detected moisture can be determined, such as at a point in time and the duration to reach a maximum value or an absolute atmospheric humidity at a specific instant, which can be compared with the values stored in the controller. From this, it is possible to determine the laundry load quantity that is located in the spin dryer, and as a result a program sequence for drying the load can be optimized.

Claims

1. A method for determining a laundry load quantity in dryer comprising a loading chamber with an air outlet having a moisture sensor for measuring an absolute atmospheric humidity in said air outlet comprising the steps of:

establishing a maximum value or plurality of values over time of said absolute atmospheric humidity in said air outlet during operation of said dryer; and

determining said load quantity in said loading chamber using said maximum value or said plurality of values.

2. The method according to claim 1, wherein reference values for correlating said maximum value of said absolute atmospheric humidity with a specific load quantity are stored in a memory for a comparison and further comprising the step of:

determining said laundry load in said loading chamber by comparing said maximum value of said absolute atmospheric humidity with said reference values.

11. Method according to claim 1, wherein a time duration of a plateau-like course of said absolute atmospheric humidity is established and from said course a residual humidity of said washing load following said washing process is determined, wherein the longer said time duration of said plateau phase is, the higher said residual humidity is assumed to be.

12. Method according to claim 11, wherein said plateau phase is defined in such a way that during it a variation of said absolute atmospheric humidity of max 10% below said maximum value is allowed.

3. The method for determining a laundry load quantity in a loading chamber of a spin dryer having an air outlet in which an absolute atmospheric humidity in said air outlet from said loading chamber is measured, wherein said laundry load quantity in said loading chamber is determined by establishing a value for said absolute atmospheric humidity in said air outlet at a defined point in time following a start of operation of said spin dryer.

4. The method according to claim 3, wherein reference values of absolute atmospheric humidity at a point in time equal to the defined point in time associated with a specific load quantity are stored for a comparison, and further comprising the step of:

determining said laundry load quantity by comparing said measured absolute atmospheric humidity of said air outlet with said reference values at the defined point in time following the start of operation.

5. The method according to claim 3, wherein said defined point in time is more than 5 minutes and less than 40 minutes following said start of operation of said spin dryer.

6. The method according to claim 3, wherein said defined point in time is between 15 to 20 minutes.

7. A method for determining a laundry load quantity in a loading chamber with an air outlet of a spin dryer having a sensor to measure an absolute atmospheric humidity in said air outlet from said loading chamber comprising the steps of:

determining a gradient of said absolute atmospheric humidity from a plurality of measurements of said absolute atmospheric humidity in said air output;

determining said gradient is of a specific value; and

comparing said specific value of said gradient with a plurality of reference values each associated with a respective gradient further associated with a respective load quantity stored in a memory in order to determine said laundry load.

8. The method according to claim 7, wherein said specific value of said gradient is approximately zero.

9. The method according to claim 7, wherein said specific value of said gradient is negative.

10. The method according to claim 7, wherein use is made of an instant at which said absolute atmospheric humidity gradient falls sharply below zero.

13. A spin dryer comprising:

a laundry chamber for containing a laundry load of a certain quantity for drying;

an air inlet for providing heated air for drying said laundry load during operation;

an air heater for heating said air;

a fan for forcing said air into said laundry chamber;

an air output for exhausting the air from the laundry chamber;

a sensor for measuring an absolute atmospheric humidity in said air outlet;

a controller connected to said sensor for measuring and storing a plurality of values of said absolute atmospheric humidity, said controller controlling said air heater and said fan,

wherein said controller is configured to determine the quantity of said laundry load by analyzing said one or more measurements of said absolute atmospheric values with respect to stored reference values, and control said air heater and said fan based on said laundry load.

14. The spin dryer of claim 13 wherein said controller is configured to determine the laundry load by determining a maximum value of one of said measurements of said absolute atmospheric values at a point in time and compares said maximum value for said point in time with said stored reference values.

15. The spin dryer of claim 13 wherein said controller is configured to determine the laundry load by using a single measurement of said absolute atmospheric value at a predefined point in time following a start of operation of said spin dryer and comparing said single measurement with said stored reference values.

16. The spin dryer of claim 13 wherein said controller is configured to determine a gradient associated with said plurality of measurements of said absolute atmospheric values and compare a value of said gradient at a point in time with said stored reference values.