Clothes dryer

Abstract

 The present invention relates to a clothes dryer comprising a stationary housing (1), a rotatable drum (2) and means of heating (31), ventilation (43), transmission (42) and control installed within said housing (1). The said heating means (31) is formed by several infrared lamps (31), such as quartz tungsten halogen lamps, mounted on the interior wall of said drum (2). The present invention optimizes the structure of the clothes dryer so that the clothes dryer has the advantages of lower power consumption, time-saving, adjustability of temperature and lower temperature within said drum, etc.

Description

[0001] The present invention relates to a clothes dryer, and in particular to an improvement in heating means of the clothes dryer.

[0002] A conventional clothes dryer consists of a stationary housing, a rotatable drum, and means for heating, ventilation, transmission and control installed within said housing. The conventional heating means is a PTC semiconductor heating element mounted on the wall of said housing at the site of the ventilation inlet. Once connected to the power supply, the heating element increases its own temperature and then radiates the heat into the surrounding air. The ventilation means will draw the heated air into the drum through the ventilation inlet and the heated air will dry clothes within the drum. The mechanism of this kind of clothes dryer is to heat the clothes to a relatively high degree, under which the rate of water vaporization out of the clothes is higher than that of moisture absorption into the clothes in the environment. The disadvantages of a conventional clothes dryer include:

1) the consumed electric power is used not only to vaporize water from the clothes but also to heat up the clothes and a large quantity of air, which results in higher electricity and power consumption and lower heating efficiency;

2) the PTC heating element is mounted outside of the drum and the heated air needs to be transmitted into the drum through the ventilation inlet and, as a result, the temperature outside of the drum is much higher than that inside of the drum and more power is consumed;

3) as this clothes drying method needs to heat up the clothes within the drum to a higher degree, it will prolong the time for clothes drying and damage the clothes to some degree at the higher temperature; and

4) the heating temperature cannot be adjusted based on the clothes materials.

[0003] An object of the present invention is to compensate the technical deficiency of current clothes dryers by the use of a new type of heating means. The present invention optimizes the structure of a clothes dryer so that the said clothes dryer has the advantages of lower power consumption, time-saving, adjustability of temperature, and lower temperature within said drum, etc.

[0004] The present invention consists in a clothes dryer comprising a stationary housing, a rotatable drum mounted within said housing, and means for heating, ventilation, transmission and control, characterized in that said heating means comprises one or more infrared lamps.

[0005] The lamp(s) may be mounted on the interior wall of the drum, and power may be supplied to the lamp(s) by a current inlet ring connected to a drum-supporting shaft, while an electric brush mounted on the outer wall of said drum is connected to said current inlet ring. If a perforated drum is used, said lamp(s) can, additionally or alternatively, be mounted on the interior wall of said housing.

[0006] In order to improve the effect of water vaporization, said control means preferably comprise a thyristor that is used for controlling the power to said lamps; and the wavelength of infrared radiation of said lamps preferably ranges 1.2-6.5µ: The infrared lamp(s) are preferably made of quartz tungsten halogen lamps sintered with an infrared-radiating layer of a mixture of quartz powder and a non-metal oxide, the oxygen enriched porous silica powder.

[0007] The clothes drying process of the present invention is described as follows: the clothes after washing and spinning are put into the drum. Upon selection of the drying programme, the motor assembly is activated and the damp clothes are tumbled by the rotation of the drum. Once the infrared-radiating lamps are connected to the power, the lamps light up and radiate the infrared directly and evenly to the damp clothes. Under the direct infrared radiation, water molecules are vaporized out of the clothes and then the hot damp air within the drum is ventilated out by a fan. This makes the clothes dry.

[0008] The mechanism of the present invention is to dry the clothes by using the method of radiating infrared to the clothes. The best source of infrared radiation is to use quartz tungsten halogen lamps coated with oxygen enriched porous silicon. The radiating efficiency will particularly increase when the infrared wavelength is in the range of 2-5µ. The infrared radiation under this wavelength enables water molecules to be vaporized by unleashing the binding of surrounding water aggregates. Therefore, there is no need to heat the water to a higher degree so as to enhance the effect of water vaporization.

[0009] The present invention has the following characteristics:

1. High efficiency: applying infrared radiation, especially with a designated infrared wavelength, to the clothes drying process produces not only the macro heating radiation effect, but also the effects of micro water molecule activation through the spectrum corresponding to thermal vibration and rotation of water molecules, and the effects of infrared heating and microwave drying. The efficiency of dehydration is much more enhanced as compared with the conventional method of drying clothes through heat.

2. The energy-saving heating means mounted within the drum enables the electricity consumption to be greatly reduced.

3. Clothes are dried under a lower temperature, which is especially suitable for high-quality clothes made of low heat-resistant material.

4. The heating power can be adjusted through the thyristor that controls the electric circuit, so that different types of clothes can be dried under an optimal condition.

[0010] The invention will be described in more detail, by way of example, with reference to the accompanying drawings, in which:-

Figure 1 is a sectional view of the interior of a clothes dryer in accordance with one embodiment of the invention;

Figure 2 illustrates the exterior design of the embodiment of Figure 1; and

Figure 3 illustrates an embodiment of the main electric circuit of the present invention.

[0011] Referring to the drawings, the clothes dryer comprises a stationary housing 1, a rotatable drum 2, and means for heating, ventilation, transmission and control of the dryer.

[0012] The drum 2 is mounted with its rotational axis horizontal in the central location of the housing 1. The front of the housing has a round opening 21 corresponding to a monitoring window 111 on the housing door 11. The housing has a supplementary supporting function and a felt seal 6 is installed in between in order to reduce the air entrance through any crevices. At the back of the drum a shaft sleeve 22 is connected to a supporting shaft 51. The supporting shaft 51 is fixed on a stand 12 at the back of the housing. A motor 52 rotates the drum 2 along the supporting shaft through a pulley (not shown) installed on the outer wall of the drum.

[0013] The lower front of the housing has a ventilation inlet 41. A fan 42 is installed on the supporting shaft 51 and a protection cap 13 driven by the motor 52 is used to cover the fan 42. On the protection cap there is a ventilation outlet 43. When the fan turns, fresh air will be drawn in through the ventilation inlet 41 and will be circulated in the drum 2. Then the damp air caused by water vaporization will be exhausted out through the ventilation outlet 43.

[0014] A number of lamps 31, for example between three to six lamps, are evenly mounted on the interior side wall of the drum 2. The lamps are heat-insulated by a ceramic stand on the lamp bracket. Outside of the lamps, there is a netted lampshade 32 in an arch shape to cover the lamps. The special infrared source used in the present invention has a wavelength of 3-4µ. The surface temperature of the lamps is set at 300°C. The selected lamp is a quartz tungsten halogen lamp. In accordance with the method of making tungsten halogen lamps, a mixed layer of quartz powder and a non-metal oxide, the oxygen enriched porous silica powder, is sintered on the lamp. In order to make sintering work easier, 25% of quartz powder needs to be added to the mixture. The useful life of the lamp is approximately 1,000 hours. The illuminated lamp does not break when splashed with water. The coated layer is non-poisonous, as evidenced by a lab test.

[0015] The power wire for the lamps is connected to an electric brush 33 through the wall of the drum and the electric brush is connected to a current inlet ring. The wire of the current inlet ring is placed through the supporting shaft 51, which is controlled by the main electric circuit for switch control and power level.

[0016] The main electric circuit of the dryer, as shown in Figure 3, consists of a timer electric circuit I, a power control electric circuit II, and an indicating electric circuit III.

[0017] The timer electric circuit I is used for setting the clothes drying time and consists of a timer DS (model SG CC4hB) which controls switching of the motor and lamps, a temperature controller, and a moisture controller WK. When the temperature increases to an alarming threshold, automatic switch-off will avoid clothes damage. The present invention has a fusing wire BX installed and there is a switch K on the door of the dryer. When the door is open or not closed tightly, the switch K prevents the main electric circuit from being activated so as to avoid any potential danger.

[0018] The power control electric circuit II consists of a dura-directional thyristor SCR (Model BTA 140), trigger diode DB, resistor R1, potentiometer R2 and capacitor C2. The electric potentiometer R2 is controlled by adjusting the power on a control panel 14. The power output of three groups of infra-red radiating lamps (DG1,DG2,DG3) can also be adjusted through the change of conduction angle of the thyristor SCR.

[0019] The indicating electric circuit III consists of LED D1, diode D2 and resistor R3 and can monitor the working condition and power level of the lamps DG1,DG2,DG3.

[0020] The working mechanism of the electric circuits is explained as follows: The power supply of the motor MD is controlled by the timer DS as well as the door switch K. The power level of three lamps DG1,DG2,DG3 are simultaneously controlled by the thyristor SCR. The charging electric circuit is formed by R1,R2, and C2 and changing the resistance of R2 can change the charging time. When the electric potential of C2 reaches a certain level, the trigger diode DB and the dura-directional thyristor SCR are connected in succession, and then the power is provided. Through adjustment of R2, the conduction angle of the thyristor can be controlled so that the power level of the lamps can be adjusted. The indicating electric circuit II is formed by LED D2, diode D3 and resistor R3, of which R3 restrains the current volume and D2 protects the LED from breakdown. There is also a temperature controller on the electric circuit, which is used for switching off the electric circuit when the temperature exceeds a certain level. The fuse wire BX is installed to avoid large current volume surging through the electric circuit.

[0021] The control panel is installed on the top of the housing. The clothes drying time, the highest allowable temperature and the clothes drying method can be selected based on the clothes material and number of clothes, the power of the clothes dryer being adjustable through the conduction angle of the thyristor. The operation can be performed automatically or manually. The sensors of temperature and moisture are placed on the lampshade and ventilation outlet. Based on the sensors feedback, the power of the lamps is adjusted.

[0022] As shown in Figure 2, the housing door 11 is located in the front centre of the housing 1. There is a monitoring window 111 on the housing door and the monitoring window is made of dark plexiglass. There is a control panel 14 on the upper front of the housing. On the control panel there is a power control knob 141 and a timer knob 142. The lower front of the housing has a decorative cover 15 on which a trade mark and decorative graph can be printed. The control panel and the decorative cover are interchangeable. When the dryer is placed on the ground, the control panel can be put on the top of the dryer to avoid ground water damage to the panel. When the dryer is placed on a clothes washer or somewhere above the ground, the control panel can be installed at the bottom of the dryer for handy operation.

Claims

1. A clothes dryer comprising a stationary housing (1), a rotatable drum (2) mounted within said housing (1), and means for heating (31), ventilation (43), transmission (42) and control (II), characterized in that said heating means (31) comprises one or more infrared lamps (31).

2. A clothes dryer as claimed in claim 1, wherein said infrared lamp or lamps (31) are installed on an interior wall of said drum (2).

3. A clothes dryer as claimed in claim 2, wherein the power supply to said infrared lamp or lamps is provided through a current inlet ring, an electric brush (33), and a drum-supporting shaft (51), said current inlet ring being connected to said drum-supporting shaft, and said electric brush being mounted on an outer wall of said drum (2) and being connected to said current inlet ring.

4. A clothes dryer as claimed in claim 1, wherein said infrared lamp or lamps (31) are installed on an interior wall of said housing (1).

5. A clothes dryer as claimed in any preceding claim, wherein said control means (II) includes a thyristor (SCR) for controlling power to said lamp or lamps (31).

6. A clothes dryer as claimed in any preceding claim, wherein said lamp or lamps (31) emit infrared radiation of a wavelength within the range of approximately 1.2 to 6.5µ.

7. A clothes dryer as claimed in claim 6, wherein the wavelength of said emitted infrared radiation is approximately 3 to 4 µ.

8. A clothes dryer as claimed in any preceding claim, wherein the or each infrared lamp (31) comprises a quartz tungsten halogen lamp sintered with an infrared radiating layer comprising a mixture of quartz powder and a non-metal oxide.

9. A clothes dryer as claimed in claim 8, wherein said non-metal oxide is an oxygen-enriched porous silica powder.

10. A clothes dryer as claimed in claim 9, wherein said oxygen enriched porous silica powder is mixed with 25% of said quartz powder.

Drawing