EP1945849B1

EP1945849B1 - A dryer

Info

Publication number: EP1945849B1
Application number: EP06809630A
Authority: EP
Inventors: Murat Goktas; Arif Ozarslan; Hakan Ozkahraman
Original assignee: Arcelik AS
Current assignee: Arcelik AS
Priority date: 2005-10-25
Filing date: 2006-10-18
Publication date: 2011-10-12
Anticipated expiration: 2026-10-18
Also published as: EP1945849A1; WO2007049190A1; ATE528434T1; ES2374752T3

Abstract

The present invention relates to a dryer (1) wherein a multitude of different malfunctions such as the transmission means (4) not operating, for example the breaking of the belt, the fan (8) not rotating, or insufficient load (L) can be detected by monitoring the pressure (P) characteristic of the air flow in the circulation channel (7) by means of the pressure sensor (10) and the use of different sensors for the detection of these malfunctions is rendered unnecessary since the utilization of only one pressure sensor (10) is sufficient.

Description

The present invention relates to a dryer wherein the malfunctions that occur during the drying process are identified.
Not being able to detect correctly in due time the malfunctions of the dryers such as blockage of the filter, obstruction of the air passageway, the motor not rotating, the fan being dislocated from the motor crank, breaking up of the belt, dislocation of the belt, loosening of the belt and scraping of the drum or load related errors such as excess loading or insufficient loading of the laundry in the dryer result in a decrease in the drying performance and damaging of the laundry. In state of the art, various methods are employed to detect these malfunctions. The user is warned of the malfunctions that are identified by means of the sensors situated in the drum or in the air passageway that detect the changes in the parameters such as pressure or temperature and by measurement devices or similar means that control the operation of the drum motor.
In the United States Patent Application no. US2004159008 , a pressure sensing device is determining changes in air pressure is described.
In the International Patent Application no. W02005040483 , sensors that control the parameters of the drying process are utilized in a laundry dryer and the pressure sensor detects the interruption of the dry air entering the drying chamber. Furthermore, the parameters detected by the pressure sensor are utilized in obtaining the optimum drying results, the amount of the dry air/circulating air is adjusted by a separating means according to the detected parameters.
In Japanese Patent no. JP3085199 and the Japanese Patent Application no. JP2002233696 , the stuffed condition of the lint filter is detected by a pressure sensor utilized in the dryer. A dryer according to the preamble of claim 1 is known for example from EP-A-1 568 817 .
The aim of the present invention is the realization of a dryer wherein the malfunctions that occur during the drying process can be detected correctly and on time.
The dryer realized in order to attain the aim of the present invention is explicated in the attached claims.
In the dryer, the laundry is emplaced in a drum rotated by a belt that is actuated by means of a motor and the fan that is rotated by the same motor activates the drying air in the circulation channel to be passed over the laundry. The pressure variations of the drying air with respect to time in the circulation channel is monitored by a pressure sensor situated in the circulation channel and the malfunctions that might arise in the drying process such as the snapping or detaching of the belt, blockage of the filter, blockage of the air circulation channel, the motor or the fan not rotating, excess load or insufficient load are detected by means of the monitored pressure characteristics. The pressure values measured by the pressure sensor for detecting malfunctions are compared to the predetermined data recorded by the producer including pressure-time curves that can be observed when probable malfunctions occur in the drying process and the pressure-time curves recorded for a normal drying process.
The dryer realized in order to attain the aim of the present invention is illustrated in the attached figures, where:
Figure 1 - is the schematic view of dryer.
Figures 2 to 11 - are the pressure-time graphs showing changes of the pressure in the air circulation channel with respect to time.
The parts illustrated in the figures are numbered as follows:
1. Dryer
2. Drum
3. Motor
4. Transmission means
5. Air outlet
6. Air inlet
7. Circulation channel
8. Fan
9. Filter
10. Pressure sensor
11. Control card
The dryer (1) comprises a drum (2) inside which the load (L) namely the laundry to be dried is emplaced, a motor (3) that actuates the drum (2) to provide its rotation, a transmission means (4) that transmits the motion of the motor (3) to the drum (2), an air outlet (5) situated in front of the drum (2) through which the drying cycle air is discharged, and an air inlet (6) situated on the rear side of the drum (2) into which the dehumidified and heated air is redelivered to the drum (2), a circulation channel (7) in which the drying cycle air circulates, a fan (8) providing the circulation of the air in the drying cycle, a filter (9) providing to remove the fibers from the drying air, a pressure sensor (10) that detects the pressure (P) of the drying air in the circulation channel (7), and a control card (11) that evaluates the data received from the pressure sensor (10).
In the dryer (1) of the present invention, the control card (11) compares the curve of the drying air pressure (P) value variations with respect to time (t), measured by the pressure sensor (10), to the probable pressure (P) - time (t) curves formed when possible malfunctions occur in the drying process, as predetermined, recorded by the producer, to decide on which type of a malfunction has occurred.
The malfunctions that can occur in the dryer (1) during the drying process are the malfunctioning of the transmission means (4), for example the breaking, dislocation or loosening of the belt rotating the drum (2), blockage of the filter (9), blockage of the air inlet (6) or the air outlet (5) by the load (L), the motor (3) or the fan (8) not rotating, excess load (L), insufficient load (L), dry load (L) or absence of load (L) and the control card (11) determines which of these malfunctions has occurred.
In the dryer (1), during a normal drying process, the pressure (P) characteristic of the drying air in the circulation channel (7) is detected as regular pressure oscillations around a nominal pressure value (Pn) by the pressure sensor (10) as a result of the air with a certain pressure (P) being circulated by the fan (8) in the air circulation channel (7), the drum (2) rotating to move the load (L) and the airflow being partly hindered at certain time intervals by the load (L) moving in between the air inlet (6) and the air outlet (5) (Figure 2).
In one embodiment of the present invention, the curve of the drying air pressure (P) value variations with respect to time (t) in the circulation channel (7) measured by the pressure sensor (10) is compared to the pressure (P) -time (t) curve (Figure 2) of a prerecorded normal drying process by the control card (11) to determine whether there is a malfunction or not, then by comparing to the pressure (P) - time (t) curves of probable malfunctions, the decision is given for what type of malfunction has occurred.
In another embodiment of the present invention, the curve of the drying air pressure (P) value variations with respect to time (t) in the circulation channel (7) measured by the pressure sensor (10) is first compared to the pressure (P) -time (t) curve of the most probable malfunctions, thus identifying the malfunction takes less time.
The comparison of the pressure (P) value variations with respect to time (t) measured by the pressure sensor (10) to the prerecorded pressure (P) -time (t) curves is carried out by the control card (11) at certain time intervals during the drying cycle and when a malfunction is detected the user is warned according to the type of the malfunction.
If the oscillation amplitude of the drying air pressure (P) values measured by the pressure sensor (10) drops suddenly and if the continuity in a constant value around the nominal pressure (Pn) is detected, the control card (11) decides that the transmission means (4) is not functioning, that e.g. the belt is broken or dislocated (Figure 3). When the transmission means (4) is out of order, the motor (3) and the fan (8) continues to operate, carrying on the air flow in the circulation channel (7) but since the drum (2) has stopped and hence the load (L) in the drum (2) does not move, an un-oscillated pressure (P) characteristic with a nearly constant value is observed.
If the oscillations of the drying air pressure (P) values measured by the pressure sensor (10) are detected to reduce irregularly and to approach the nominal pressure (Pn), the control card (11) decides that the transmission means (4) does not rotate the drum (2) from time to time, e.g. the belt is loosened and functions partly (Figure 4). When the transmission means (4) rotates the drum (2) irregularly, the air flow continues in the drum (2) since the motor (3) and the fan (8) continue functioning regularly, however since the load (L) moves irregularly, a pressure (P) characteristic composed of irregular oscillations is observed.
If the drying air pressure (P) values measured by the pressure sensor (10) are detected to increase incrementally as compared to the nominal pressure (Pn) and to approach a high pressure (P) value with a decrease in the oscillation amplitude, then the control card (11) decides the blockage of the filter (9) (Figure 5). In this case, the fan (8) continues to deliver air into the drum (2) but the blockage of the filter (8) by the fibers cause the pressure (P) to increase. The pressure sensor (10) can be positioned before or after the filter (9) in the dryer (1) in the direction of the air flow.
If the drying air pressure (P) values measured by the pressure sensor (10) are detected to increase suddenly as compared to the nominal pressure (Pn) and to approach a high pressure (P) value with a decrease in the oscillation amplitude, then the control card (11) decides that the load (L) is stuck in the air outlet (5) or the air inlet (6) and obstructs the air flow (Figure 6). In this case, the fan (8) continues to deliver air but the load (L) obstructing the air flow path causes the nominal pressure (Pn) to increase suddenly.
If the drying air pressure (P) values measured by the pressure sensor (10) are detected to approach zero, thus there is no flow of air, then the control card (11) decides that the fan (8) is not functioning due to dislocation or break-up, or that the motor (3) is not rotating (Figure 7).
If the drying air pressure (P) values measured by the pressure sensor (10) are detected to have high amplitude oscillations as compared to the normal conditions, then the control card (11) decides that the amount of the load (L) in the drum (2) is insufficient (Figure 8). The insufficient amount of load (L) emplaced in the drum (2) tends to be swung as a bundle, blocking and opening the air passage as a bundle, causing the detected oscillation amplitude of the pressure (P) to be high.
If the drying air pressure (P) values measured by the pressure sensor (10) decreases as compared to the nominal pressure (Pn) and the oscillation amplitude is detected to decrease, then the control card (11) decides that the load (L) in the drum (2) is dry (Figure 9). Since the dry load (L) blocks the air flow less than the wet laundry, the amplitude of the pressure (P) decreases and the nominal pressure (Pn) is detected to decrease a little.
If the drying air pressure (P) values measured by the pressure sensor (10) are always above the nominal pressure (Pn) and low oscillation amplitude is detected, then the control card (11) decides that there is excess load (L) in the drum (2) (Figure 10). Since excess load (L) blocks the air flow more than the normal load (L), the pressure (P) increases and its amplitude decreases.
If the pressure (P) values of the drying air measured by the pressure sensor (10) are near the nominal pressure (Pn) and a continual motion with no oscillation is detected, then the control card (11) decides that there is no load (L) in the drum (2) (Figure 11). When there is no load (L), the air in the drum (2) continues flowing with an almost constant pressure (P) and pressure (P) oscillation cannot be detected since there is no load (L) barrier in its way.
In the dryer of the present invention, a multitude of different malfunctions can be identified by monitoring the pressure (P) characteristic of the air flow in the circulation channel (7) by means of the pressure sensor (10), economy is made by not using a multitude of sensors and from the space allocated for these sensors and their connection cables to detect these malfunctions, also a simpler software for the control of the dryer (1) is sufficient.

Claims

A dryer (1) comprising a drum (2) inside which the laundry is emplaced, a motor (3) that actuates the drum (2) to provide rotation, a transmission means (4) that transmits the motion of the motor (3) to the drum (2), a circulation channel (7) in which the drying cycle air circulates, an air outlet (5) and an air inlet (6), a fan (8) providing the circulation of the drying cycle air, a filter (9) providing to remove the fibers from the drying air, a pressure sensor (10) that detects the pressure (P) of the drying air in the circulation channel (7), and characterized by a control card (11) that compares the variations of the oscillation amplitudes in the curve of the drying air pressure (P) values with respect to time (t), measured by the pressure sensor (10), to the possible pressure (P) - time (t) curves formed when possible malfunctions occur in the drying process, predetermined and recorded by the producer, to decide on which type of malfunction has occurred.
A dryer (1) as in Claim 1, characterized by the control card (11) that identifies which of the malfunctions such as out-of service transmission means (4), blockage of the filter (9), blockage of the air inlet (6) or the air outlet (5) by the load (L), the motor (3) or the fan (8) not rotating, excess load (L), insufficient load (L), dry load (L) or the absence of load (L) have occurred according to the variations of the oscillation amplitudes of the drying air pressure (P) values with respect to time (t), measured by the pressure sensor (10).
A dryer (1) as in Claim 1, characterized by the control card (11) that compares the curve of the drying air pressure (P) value variations of the oscillation amplitudes with respect to time (t) measured by the pressure sensor (10) first to the pressure (P) -time (t) curves of the most probable malfunctions, identifying the type of the malfunction in a short time.
A dryer as in Claim 1, characterized by the control card (11) that compares the curve of the drying air pressure (P) value variations of the oscillation amplitudes with respect to time (t) measured by the pressure sensor (10) to the prerecorded pressure (P) - time (t) curve of a normal drying process to determine whether or not a malfunction has occurred, then deciding on the type of the malfunction by comparing to the pressure (P) - time (t) curves of the probable malfunctions.
A dryer (1) as in any one of the above claims, characterized by the control card (11) that compares the drying air pressure (P) value variations of the oscillation amplitudes with respect to time (t) measured by the pressure sensor (10) to the prerecorded pressure (P) - time (t) curves at certain time intervals during the drying cycle and when a malfunction is detected, warns the user according to the type of the detected malfunction.
A dryer (1) as in Claim 2, characterized by the control card (11) which decides that the transmission means (4) is not functioning when the oscillation amplitude of the drying air pressure (P) values measured by the pressure sensor (10) drops suddenly and continues at a constant value around the nominal pressure (Pn) without oscillations is detected.
A dryer (1) as in Claim 2, characterized by the control card (11) which decides that the transmission means (4) does not rotate the drum (2) from time to time when the oscillation amplitudes of the drying air pressure (P) values measured by the pressure sensor (10) are detected to decrease irregularly and the said air pressure (P) values to approach the nominal pressure (Pn).
A dryer (1) as in Claim 2, characterized by the control card (11) which decides that the blockage of the filter (9) when the drying air pressure (P) values measured by the pressure sensor (10) are detected to increase incrementally as compared to the nominal pressure (Pn) and to approach a high pressure (P) value with a decrease in the oscillation amplitude.
A dryer (1) as in Claim 2, characterized by the control card (11) which decides that the load (L) is stuck in the air outlet (5) or the air inlet (6), obstructing the air flow when the drying air pressure (P) values measured by the pressure sensor (10) are detected to increase suddenly as compared to the nominal pressure (Pn) and to approach a high pressure (P) value with a decrease in the oscillation amplitude.
A dryer (1) as in Claim 2, characterized by the control card (11) which decides that the fan (8) is not functioning due to dislocation or break-up or that the motor (3) is not rotating when the oscillation amplitudes of the drying air pressure (P) values measured by the pressure sensor (10) are detected to approach zero.
A dryer (1) as in Claim 2, characterized by the control card (11) which decides that the amount of the load (L) in the drum (2) is insufficient when the drying air pressure (P) values measured by the pressure sensor (10) are detected to have high amplitude oscillations as compared to the normal conditions.
A dryer (1) as in Claim 2, characterized by the control card (11) which decides that the load (L) in the drum (2) is dry when the drying air pressure (P) values measured by the pressure sensor (10) decrease as compared to the nominal pressure (Pn) and the oscillation amplitude is detected to decrease.
A dryer (1) as in Claim 2, characterized by the control card (11) which decides that there is excess load (L) in the drum (2) when the drying air pressure (P) values measured by the pressure sensor (10) are always above the nominal pressure (Pn) and a low oscillation amplitude is detected.
A dryer (1) as in Claim 2, characterized by the control card (11) which decides that there is no load (L) in the drum (2) when the drying air pressure (P) values measured by the pressure sensor (10) are near the nominal pressure (Pn) and a continual motion with no oscillation is detected.