Tumble dryer and method for drying laundry using a tumble dryer

Patent metadata

Field	Value
Publication number	US-11021837-B2
Application number	US-201916525712-A
Country	US
Kind code	B2
Filing date	Jul 30, 2019
Priority date	Aug 6, 2018
Publication date	Jun 1, 2021
Grant date	Jun 1, 2021

Abstract

A tumble dryer has a drum for laundry, a drive motor for the drum, an air supply to the drum and an air discharge from the drum, a fan, including a fan drive, for generating an air stream to the drum through the air supply and away from the drum through the air discharge, and also heating means for heating the air stream. The temperature of and the moisture in the air which is discharged from the drum are detected. The profile of said temperature and moisture is compared with prespecification curves, which are stored in a memory, for the profile of said temperature and moisture by means of calculation means depending on the drying phase of the laundry. The operating point of the prespecification curve at which the drying program is located is determined in this way. The control arrangement influences the further drying program, on the basis of the operating point, by way of adjusting the temperature and/or the intensity of the air stream.

First claim

The invention claimed is:

1. Tumble dryer comprising:
a drum for holding laundry which is to be dried,
a drive motor for said drum,
an air supply to said drum,
an air discharge from said drum,
a fan for generating an air stream to said drum through said air supply and away from said drum through said air discharge,
a fan drive for said fan,
heating means for heating said air stream,
temperature detection means for detecting a temperature of air which is supplied to said drum or air which is discharged from said drum,
moisture detection means for detecting a moisture in said air which is supplied to said drum or said air which is discharged from said drum,
a control arrangement comprising:
a memory, wherein at least one prespecification curve for a profile of temperature or moisture with respect to time for a specific drying program for laundry is stored in said memory,
calculation means, wherein said calculation means are designed to compare currently detected values for said temperature or said moisture with a prespecification curve depending on a drying phase of said laundry during a drying program and to determine an operating point of said prespecification curve at which said drying program is located,

wherein said control arrangement is designed for influencing a further drying program, on a basis of said operating point, by way of adjusting said temperature of said air stream by influencing said heating means and/or by way of adjusting an intensity of said air stream by influencing said fan.

2. Tumble dryer according to claim 1 , wherein said air supply is provided at most 10% below a highest point of said drum.

3. Tumble dryer according to claim 2 , wherein said air supply is provided above said highest point of said drum.

4. Tumble dryer according to claim 1 , wherein said fan is at most 50 cm away from said drum.

5. Tumble dryer according to claim 1 , wherein said fan drive is a dedicated drive only for said fan, wherein said fan drive is designed as one structural unit together with said fan.

6. Tumble dryer according to claim 1 , wherein said fan has an inductively heatable fan rotor as heating means, wherein said fan rotor has a plurality of fan blades, wherein at least one of said fan blades is at least partially composed of, or contains, a material which can be heated by means of a magnetic field generating means.

7. Tumble dryer according to claim 6 , wherein said at least one magnetic field generating means is arranged adjacent to said fan rotor or at least partially surrounds said fan rotor and is arranged on a fan housing of said fan.

8. Tumble dryer according to claim 7 , wherein said at least one magnetic field generating means has or is at least one induction coil, wherein said temperature detection means comprise said fan rotor and said magnetic field generating means as an induction coil.

9. Tumble dryer according to claim 8 , wherein said temperature of said air which is discharged from or supplied to said drum can be determined from an activation of said induction coil.

10. Tumble dryer according to claim 7 , wherein said at least one magnetic field generating means has at least one permanent magnet.

11. Tumble dryer according to claim 6 , wherein said at least one magnetic field generating means is arranged outside a fan housing or outside said air supply.

12. Tumble dryer according to claim 6 , wherein said at least one magnetic field generating means runs outside said fan rotor with a radial extent.

13. Tumble dryer according to claim 12 , wherein said at least one magnetic field generating means is arranged radially outside said fan rotor and in an encircling manner as an induction coil with a coil center axis which runs parallel to a rotation axis of said fan rotor or coincides with said rotation axis of said fan rotor.

14. Tumble dryer according to claim 1 , wherein said moisture detection means comprise said fan and, respectively, a fan drive, wherein a level of said moisture can be determined from an activation of said fan drive of said fan in such a way that a high torque is to be provided by said drive when there is a high level of said moisture in said air which is moved by said and a low torque is to be provided by said fan drive when there is a low level of said moisture in said air which is conveyed by said fan.

15. Tumble dryer according to claim 14 , wherein said level of said moisture can be determined by monitoring a phase shift between current and voltage in said fan drive.

16. Tumble dryer according to claim 1 , wherein said drum is internally free of sensors.

17. Tumble dryer according to claim 16 , wherein said drum does not have any sensors on an outer side either.

18. Method for drying laundry, which is to be dried, using a tumble dryer, wherein said tumble dryer has:
a drum for holding laundry which is to be dried,
a drive motor for said drum,
an air supply to said drum,
an air discharge from said drum,
a fan for generating an air stream to said drum through said air supply and away from said drum through said air discharge,
a fan drive for said fan,
heating means for heating said air stream,
temperature detection means for detecting a temperature of said air which is supplied to said drum or said air which is discharged from said drum,
moisture detection means for detecting a moisture in said air which is supplied to said drum or said air which is discharged from said drum,
a control arrangement comprising:
a memory in which at least one prespecification curve for a profile of said temperature or said moisture with respect to time for a specific drying program for laundry is stored,
calculation means in order to compare currently detected values for said temperature or said moisture with a prespecification curve during a drying program and in order to determine an operating point of said prespecification curve at which said drying program is located,

the method comprising the steps of:
detecting current values for said temperature and/or said moisture during a drying program,
comparing said current values for said temperature and/or said moisture with a prespecification curve,
determining said operating point of the prespecification curve at which said drying program is located on a basis of said comparison,
influencing a further drying program on a basis of said operating point, in terms of adjusting said temperature of said air stream by influencing said heating means or in terms of adjusting an intensity of said air stream by influencing said fan.

19. Method according to claim 18 , wherein said further drying program is influenced in terms of said temperature or said intensity of said air stream, wherein then:
said temperature of said air stream to said drum is at least 5° C. below an average for said temperature of said air stream used up until this point,
said intensity of said air stream to said drum is at least 20% above said average for said intensity of said air stream used up until this point.

20. Method according to claim 18 , wherein said further drying program, primarily during a period of a last quarter of said drying program, is influenced in terms of said temperature or an intensity of said air stream.

21. Method according to claim 19 , wherein a fan direction and, respectively, a direction of said air stream is reversed several times at intervals in order to then draw off said air from said drum into said air supply in order to acquire information about said exhaust air in this way.

Assignees

• Ego Elektro Geraetebau Gmbh

Inventors

• Bellm Mathias
• Grill Rebecca
• Schaumann Uwe
• Schmidt Kay

Classifications

• D06F58/38 Primary

  of drying, e.g. to achieve the target humidity · CPC title

• D06F58/26

  Heating arrangements, e.g. gas heating equipment (D06F58/18 takes precedence) · CPC title

• D06F2103/54

  related to blowers or fans · CPC title

• D06F2105/32

  Air flow control means · CPC title

• D06F58/02

  having dryer drums rotating about a horizontal axis · CPC title