Method of estimating a humidity level in a steam cooking chamber of a steam cooking appliance, method or operating the steam cooking appliance and steam cooking appliance

Patent metadata

Field	Value
Publication number	US-2016374353-A1
Application number	US-201414901940-A
Country	US
Kind code	A1
Filing date	Jun 26, 2014
Priority date	Aug 19, 2013
Publication date	Dec 29, 2016
Grant date	—

Abstract

The present application in particular is related to a method of estimating a humidity level in a steam cooking chamber ( 4 ) of a steam cooking appliance ( 1 ). The method comprises successively measuring static or quasi-static pressure values (P 1 , . . . , P n ) prevailing within the steam cooking chamber ( 4 ); successively calculating from the pressure values (P 1 , . . . , P n ); and setting and using the humidity index value (EH 1 , EH n ) as an actual measure for the humidity level.

First claim

1 . Method of estimating a humidity level in a steam cooking chamber of a steam cooking appliance comprising:
a. successively measuring, with an absolute pressure sensor, static or quasi-static pressure values (P 1 , . . . , P n ) prevailing within the steam cooking chamber; b. successively calculating from the pressure values or smoothed pressure values (P 1 , . . . , P n ) via integration, numerical integration or iterative numerical integration a humidity index value (EH 1 , . . . , EH n ); and c. setting and using the humidity index value (EH 1 , . . . , EH n ) as an actual measure for the humidity level.

2 . Method according to claim 1 , wherein the pressure sensor, via which the pressure values (P 1 , . . . , P n ) are measured, is arranged outside the cavity and is connected with the inner cavity volume via a communicating pipe.

3 . Method according to claim 1 , wherein the pressure sensor communicates with a zone within the cavity essentially unaffected by forced convection generated in the cavity by a fan.

4 . Method according to claim 1 , wherein the pressure values (P 1 , . . . , P n ) are measured at successive timepoints (t 1 , . . . , t n ) and an actual humidity index value (EH n ) is iteratively calculated from a preceding humidity index value (EH n-1 ).

5 . Method according to claim 1 , wherein the successive humidity index values (EH 1 , . . . , EH n ) are calculated in a weighted integration, weighted numerical integration or weighted iterative numerical integration.

6 . Method according to claim 1 , wherein the humidity index values (EH 1 , . . . , EH n ) are calculated according to the following calculation rule:
a. EH n =EH n-1 +(P n −P n-1 )*K up −EH n-1 *K relax , if P n >P n-1 or b. EH n =EH n-1 +(P n −P n-1 )*K down −EH n-1 *K relax , if P n ≦P n-1 ; wherein EH n and EH n-1 are successive humidity index values; P n and P n-1 are successive pressure values or successive smoothed pressure values, K up is a first weighting factor, K down is a second weighting factor, and K relax is a relaxation factor.

7 . Method according to claim 6 , wherein the factors K up , K down , and K relax are calibrated for each application.

8 . Method according to claim 1 , wherein the pressure sensor is adapted to measure pressures in the range from 0 to 30 Pa.

9 . Method according to claim 1 , wherein the pressure sensor is a differential pressure sensor which is adapted to measure a difference pressure between the inside of the cavity and the outside of the cavity.

10 . Method of operating a steam cooking process in a steam cooking chamber of a steam cooking appliance, comprising:
a) calculating an actual measure (EH n ) of the humidity level according to a method according to claim 1 ; and b) activating or deactivating steam generation in dependence of the actual measure (EH n ) and at least one preset value of the humidity level.

11 . Cooking appliance comprising a steam cooking functionality with a steam cooking chamber, a control unit, an absolute pressure sensor and steam generation unit, respectively being coupled to the control unit, wherein the control unit is adapted to estimate a humidity level according to a method of claim 1 , and wherein the control unit is adapted to affect steam generation by controlling the steam generation unit in dependence of the estimated humidity level.

12 . Cooking appliance according to claim 11 , wherein the absolute pressure sensor is mounted outside the cavity, and wherein the pressure sensor is connected to the inner volume of the cavity by a communicating pipe.

13 . Cooking appliance according to claim 12 , comprising a fan for forced ventilation or convection, wherein the communication pipe is connected to a section of the cavity volume which is essentially unaffected by the fan.

14 . Cooking appliance according to claim 11 , wherein the pressure sensor is a differential pressure sensor and is adapted to calculate a difference pressure between the inside of the cavity and the outside of the cavity.

15 . Cooking appliance according to claim 11 , wherein the pressure sensor is adapted to sense pressures in the range between 0 and 100 Pa, preferably between 0 Pa and 20 Pa.

Assignees

• Electrolux Appliances AB

Inventors

• Faraldi Paolo
• Furlanetto Riccardo
• Gattei Lorenzo
• Pellis Michele

Classifications

• F24C15/003

  moisturising of air · CPC title

• A21B3/04 Primary

  Air-treatment devices for ovens, e.g. regulating humidity · CPC title

• A23L5/13

  using water or steam · CPC title

• A47J27/04

  for cooking food in steam; Devices for extracting fruit juice by means of steam {; Vacuum cooking vessels (steam-heated vessels for hotels, restaurants or canteens A47J27/16)} · CPC title

• A23V2002/00

  Food compositions, function of food ingredients or processes for food or foodstuffs · CPC title