Detecting filter clogging

Patent metadata

Field	Value
Publication number	US-9872597-B2
Application number	US-201214439346-A
Country	US
Kind code	B2
Filing date	Nov 8, 2012
Priority date	Nov 8, 2012
Publication date	Jan 23, 2018
Grant date	Jan 23, 2018

Abstract

The present invention relates to a method of, and a device for, detecting clogging of a dishwasher filter. The device is arranged to drain the dishwasher on process water, measure operating current of a motor driving a dishwasher drain pump and determine whether the dishwasher filter is clogged based on the measured drain pump motor operating current.

First claim

The invention claimed is:

1. A method of detecting clogging of a dishwasher filter, comprising the steps of:
draining the dishwasher on process water;
measuring operating current of a motor driving a dishwasher drain pump; and
determining whether the dishwasher filter is clogged based on the measured drain pump motor operating current, wherein the step of determining whether the dishwasher filter is clogged based on the measured drain pump motor operating current comprises comparing the measured drain pump motor operating current to a first predetermined current threshold value, wherein the filter is considered to be clogged if the measured current is below the first predetermined current threshold value.

2. The method of claim 1 , further comprising the step of:
comparing the measured drain pump motor operating current to a second predetermined current threshold value when a predetermined time period has expired from the start of the draining, wherein the filter is considered to be clogged if the measured current is above the second predetermined current threshold value after the predetermined time period has expired.

3. The method of claim 1 , further comprising the step of:
averaging a number of measured drain pump motor operating current values over a predetermined averaging time period, wherein the filter is considered to be clogged if the average operating current is below a predetermined average current threshold value.

4. The method of claim 1 , further comprising the step of:
signaling, via an indicator of the dish washer, that the filter is clogged.

5. The method of claim 1 , further comprising the step of:
controlling rotational speed of the motor driving the drain pump such that the rotational speed is lowered from a first value to a second value when the dishwasher is drained on process water.

6. A computer program comprising computer-executable components for causing a device to perform the steps recited in claim 1 when the computer-executable components are run on a processing unit included in the device.

7. A computer program product comprising a computer readable medium, the computer readable medium having the computer program according to claim 6 embodied therein.

8. The method of claim 1 , wherein the dishwasher drain pump is disposed downstream of the filter.

9. The method of claim 1 , wherein comparing the measured drain pump motor operating current to the first predetermined current threshold value occurs instantly.

Assignees

• Electrolux Home Products Corp Nv
• Electrolux Home Products Corp Nv

Inventors

• Pers Per-Erik
• Svanbom Petter

Classifications

• A47L15/0049 Primary

  Detection or prevention of malfunction, including accident prevention (arrangements to prevent clogging of filters A47L15/4208; safety arrangements for preventing water damage A47L15/421) · CPC title

• A47L2501/26

  Indication or alarm to the controlling device or to the user · CPC title

• A47L15/4202 Primary

  Water filter means or strainers · CPC title

• A47L2401/08

  Drain or recirculation pump parameters, e.g. pump rotational speed or current absorbed by the motor · CPC title

• A47L15/4208

  Arrangements to prevent clogging of the filters, e.g. self-cleaning · CPC title