Method of operating a steam generator, steam generator and cooking device with a steam generator

Patent metadata

Field	Value
Publication number	US-11980314-B2
Application number	US-202016952430-A
Country	US
Kind code	B2
Filing date	Nov 19, 2020
Priority date	Dec 16, 2019
Publication date	May 14, 2024
Grant date	May 14, 2024

Abstract

A steam generator has a water container and an upper heating device and a lower heating device, a first temperature detection device covering a temperature detection area including the area covered by the two heating devices, a control device for monitoring and evaluating the first temperature detection device and for controlling the activation state of the two heating devices. A flat first temperature detection device covers the outside of the container, and a second spot-like temperature sensor is located on the water container in a region of an upper border of the upper heating device. Both temperature detection devices are used to activate and deactivate the two heating devices such that at first the lower heating device is activated to start generating steam as fast as possible.

First claim

The invention claimed is:

1. A method of operating a steam generator, said steam generator comprising:
a water container,
two heating devices on said water container, which are located in different height regions separated from each other in a vertical direction, one said heating device being an upper heating device and an other said heating device being a lower heating device,
a first temperature detection device covering a temperature detection area, wherein said temperature detection area comprises at least an area covered by said two heating devices,
a second temperature detection device in a form of a spot-like temperature sensor being located on said water container in a region of an upper border of said upper heating device, and
a control device for evaluating said first temperature detection device and said second temperature detection device and for activating and deactivating said two heating devices,
with steps of:
filling said water container with water for a predefined first filling duration D 1 ,
after said first filling duration D 1 has elapsed, said lower heating device is activated, wherein said water container is continuously filled further with water and wherein said upper heating device is not activated,
in case said first temperature detection device detects a temperature exceeding a first temperature threshold T thr , said lower heating device is deactivated, wherein said water container is filled further with water,
as soon as said first temperature detection device detects any temperature below said first temperature threshold T thr , said lower heating device is activated again,
as soon as said first temperature detection device detects any temperature below said first temperature threshold T thr for a duration of at least 5 sec, said control device defines a quantity of water in said water container to be between 60% and 90% of a height of an upper rim of said lower heating device, and
as soon as said second temperature detection device detects a temperature of at least 95° C., said upper heating device and said lower heating device are both activated.

2. The method according to claim 1 , wherein said upper heating device is activated and said water container is continuously filled with water, said filling with water is stopped as soon as said first temperature detection device detects a second instance of a temperature below said first temperature threshold T thr for a second duration D 2 of between 5 sec and 10 sec.

3. The method according to claim 1 , wherein said first temperature detection device detects a temperature above said first temperature threshold T thr after said upper heating device has been activated, only said upper heating device is deactivated.

4. The method according to claim 3 , wherein if said first temperature detection device again detects a temperature above said first temperature threshold T thr within 2 sec to 5 sec after deactivating said upper heating device, said lower heating device is also deactivated.

5. The method according to claim 1 , wherein a filling rate of filling water into said water container is reduced by at least 5% if a duration of filling said water container until said second temperature detection device detects a temperature of above at least 95° C. is less than a predefined filling duration threshold D 3 .

6. The method according to claim 5 , wherein said filling rate is reduced by clocking a pumping action of a water pump filling water into said water container with said filling rate being a filling rate for the water pump.

7. The method according to claim 1 , wherein after filling said water container with water has been stopped for a first time, if said first temperature detection device detects a temperature above said first temperature threshold T thr , said upper heating device is deactivated for at least 3 sec, wherein more water is filled into said water container, and said upper heating device is then activated again.

8. The method according to claim 1 , wherein steam is generated at a first rate if only said lower heating device is activated and said upper heating device is deactivated.

9. The method according to claim 8 , wherein said first rate is between 20% and 90% below a second rate, wherein steam is generated at said second rate if said lower heating device is activated and said upper heating device is activated.

10. The method according to claim 1 , wherein a signal for stopping or starting to fill water into said water container is generated by monitoring a first derivation by time of a temperature signal of said first temperature detection device.

11. The method according to claim 1 , wherein for deactivating or activating at least one of said two heating devices, an absolute value of a temperature signal of said first temperature detection device is used or a first derivation of the temperature signal by time of said first temperature detection device is used.

12. The method according to claim 11 , wherein at least said upper heating device is deactivated or activated.

13. The method according to claim 11 , wherein after having filled said water container with water and having stopped a filling process, and wherein said first derivation by time of said temperature signal of said first temperature detection device is above a threshold value V thr , filling water into said water container is started again.

14. The method according to claim 13 , wherein said filling water into said water container is started again for a predefined second filling duration D 2 .

15. The method according to claim 13 , wherein said filling water into said water container is started again until said temperature signal of said first temperature detection device has reached a temperature signal value corresponding to a previous temperature signal value that occurred between 2 sec and 20 sec before filling said water container with water started.

16. The method according to claim 1 , wherein said temperature detected by said first temperature detection device is monitored and a predefined duration is measured until said lower heating device has not been deactivated by a temperature signal of said first temperature detection device for at least 5 sec, and the same is being done for said upper heating device until said upper heating device is not deactivated by said temperature signal of said first temperature detection device, wherein a time is measured until a lower heating device has not been deactivated for at least 5 sec, wherein a measured filling rate FR m is determined by dividing a known water volume being defined by a location of said lower heating device on said water container by a time that has elapsed when said lower heating device has been activated or has not been deactivated.

17. The method according to claim 16 , wherein said measured filling rate FR m is compared with a predefined filling rate FR d for said steam generator, wherein if said measured filling rate FR m is more than 10% below said predefined filling rate FR d , it is determined that a calcification of a filling pump is too high and a decalcification must be made or it is determined that a repair of said filling pump must be made.

18. The method according to claim 17 , wherein a signal is output for a user to execute a decalcification process of said filling pump or that said repair of said filling pump must be made.

19. The method according to claim 17 , wherein said measured filling rate FR m is 20%, 30% or 40% below said predefined filling rate FR d .

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Assignees

• Ego Elektro Geraetebau Gmbh

Inventors

• Schoenemann Konrad
• Stoetzner Elisabeth
• Erbe Sebastian
• Pawlowitsch Ralf
• Eigl Sebastian

Classifications

• A47J27/04 Primary

  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

• F22D5/26

  Automatic feed-control systems · CPC title

• A47J2027/043

  for cooking food in steam · CPC title

• H05B1/0269 Primary

  For heating of fluids · CPC title

• F22B1/284 Primary

  with water in reservoirs · CPC title