KR101668695B1 - Method for controlling dryer - Google Patents

Abstract

The present invention discloses a method of controlling a dryer that enables high energy efficiency and quickly generates high quality steam quickly. The present invention relates to a method for drying a laundry, comprising: inputting laundry to be dried into a drum of a dryer; Supplying hot air heated by the heater assembly in the drum to dry the laundry; And supplying steam generated by a steam generator disposed around the heater assembly to the drum, wherein the steam supplying step intermittently supplies water to the steam generator while the heater assembly is operated; And heating the water supplied by the steam generator using heat generated from the heater assembly.

Steam generator, heater assembly

Description

[0001] METHOD FOR CONTROLLING DRYER [0002]

The present invention relates to a method of controlling a dryer, and more particularly, to a method of controlling a steam generator for generating steam supplied into a drum of a dryer.

Generally, a dryer is a device for loading laundry in a state where washing is completed and a dehydration process is completed into a drum of a dryer, and supplying hot air into the drum to evaporate moisture in the laundry to dry the laundry.

According to the structure of the dryer, the dryer includes a drum inside the dryer into which the laundry is introduced, a driving motor for driving the drum, a blowing fan for blowing air into the drum, and a heating means for heating the air flowing into the drum . The heating means may be a resistance heater that generates heat using electric resistance, or a burner that generates heat by burning gas.

The air that exits the drum of the dryer has the moisture of the laundry in the drum and becomes hot and humid air. In this case, the dryer can be classified according to the method of treating the high temperature and high humidity air. Since the high temperature and high humidity air circulates without being discharged to the outside of the dryer, heat exchange with the outside air occurs in the condenser, A condensing dryer for condensing the air, and an exhaust dryer for discharging the hot and humid air passing through the drum directly to the outside.

However, there is a large amount of wrinkles in the laundry which has been laundered and put into the dryer, and such wrinkles are not removed during the drying process, so that there is an inconvenience that the dryer needs to be ironed again after drying. Further, there is a problem that not only these wrinkles after washing but also wrinkles and odors are generated in the course of storing clothes in the jean-den or the bacteria grow. In order to solve this problem, a steam generator was installed in a clothes dryer to spray steam on the clothes being dried in the drum to remove wrinkles and odors, and to sterilize the clothes.

Generally, the steam generator installed in the dryer has its own heater inside it, in addition to the heater that generates the hot air supplied to the drum. More specifically, the steam generator has a container for receiving a predetermined amount of water, and a heater provided in the container for heating the water contained therein. The water inside the steam generator is heated by the heat of the heater to be steamed, and the generated steam is supplied into the drum. Further, the steam generator has a storage tank for temporarily storing the water to be supplied to the container.

The conventional steam generator of the dryer needs to directly heat the supplied water by using a heater provided separately in order to make steam. However, due to the generation of steam, when the amount of water stored in the steam generator is reduced and the heater is exposed to the outside of the water, the heater may overheat. Therefore, for safety reasons, the heater must always be submerged in water. That is, the water stored in the container of the steam generator should always maintain a minimum water level to submerge the heater. For this reason, the steam generator has a water level sensor for sensing that the stored water is reduced and the water level is lowered to reach the minimum water level, and when the water level reaches the minimum water level, water is supplied from the storage tank to the container of the steam generator automatically.

Therefore, since the conventional steam generator must be equipped with a separate member such as a water level sensor for sensing the water level, the structure and manufacturing process become complicated. Further, since a heater for generating steam is separately provided in the hot air generating heater, the structure and manufacturing process are similarly complicated, and more energy is required for the operation of the dryer.

Further, in the conventional steam generator, in order to generate steam, the entire water contained in the container must be boiled by using a separate heater. Therefore, it takes a long time to generate steam, and energy is wasted.

SUMMARY OF THE INVENTION The present invention has been conceived to solve the above-mentioned problems, and it is an object of the present invention to provide a dryer having a steam generator that has a simple structure and enables easy manufacture.

It is another object of the present invention to provide a dryer having high energy efficiency.

It is another object of the present invention to provide a control method of a dryer capable of generating steam of high quality and high quality in a short time.

It is still another object of the present invention to provide a control method of a dryer that increases energy efficiency of a dryer.

In order to achieve the above object, the present invention provides a method for drying a laundry, comprising the steps of: Supplying hot air heated by the heater assembly in the drum to dry the laundry; And supplying steam generated by a steam generator disposed around the heater assembly to the drum, wherein the steam supplying step intermittently supplies water to the steam generator while the heater assembly is operated; And heating the water supplied by the steam generator using heat generated from the heater assembly.

The steam supplying step may further include intermittently operating the heater assembly before the intermittent supplying step.

The intermittent supply step may consist of intermittently driving a pump connected to a reservoir for storing a predetermined amount of water or intermittently opening a valve connected to a reservoir for storing a predetermined amount of water.

The intermittent supply step may include supplying water to the steam generator for a predetermined time and stopping supply of water for a predetermined time after the supplying step, wherein the supplying step and the stopping step are alternately repeated Lt; / RTI >

The period of the suspending step may be set to nine times the period of the supplying step, and in practice, the supplying step may be performed for 0.1 second, and the suspending step may be performed for 0.9 second. Further, the intermittent supplying step is performed between the heater assembly temperature of 62 ° C and 66 ° C.

Since steam can be generated without separately providing a heater for generating steam in the steam generator, the structure is simplified and manufacturing is facilitated due to a reduction in parts required for the manufacturing process. Therefore, the manufacturing cost of the steam generator of the present invention is reduced, and the productivity is increased. Also, since the heat of the heater assembly inside the dryer is used to generate steam, the energy consumed is reduced.

Further, in the control method according to the present invention, all water instantaneously supplied by intermittent supply is converted into steam. In addition, the control method according to the present invention uses a heater assembly for generating hot air without a separate heater for generating steam, and operates the heater assembly intermittently. Therefore, by the control method of the present invention, high-quality steam can be supplied to the drum in a short time, and the energy required for such steam generation can be reduced.

An example of a dryer according to the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a perspective view showing a dryer having a steam generator according to the present invention, and FIG. 2 is a perspective view showing a first embodiment of a steam generator. 3 is a partial perspective view showing the steam generator according to the first embodiment in more detail.

Referring to FIG. 1, a clothes dryer 100 according to the present invention includes a front cover 101, a main body including a side cover 102, a rear cover (not shown), and a top plate (not shown) And a drum 120 installed in the main body. The drum 120 is rotatably installed in the main body and accommodates laundry to be dried. The clothes dryer 100 includes a door 104 mounted on a front surface of the front cover 101 to open and close an opening of the drum 120, And a control panel 103 having various buttons for inputting conditions. The drum 120 has a hollow cylinder shape in which a front end portion and a rear end portion are opened. That is, openings are formed in the front and rear portions of the drum 120, respectively. The drum 120 is supported by a front supporter (not shown) installed at a front portion inside the main body and a rear supporter 122 (see FIG. 2) provided at a rear portion of the main body. More specifically, the front supporter is provided with an opening communicating with the opening of the front end of the drum 120, and a rim is formed on the outer periphery of the opening. The inner circumferential surface of the rim of the front supporter rotatably supports the outer peripheral surface of the front end portion of the drum 120. The opening of the front end of the drum 120 communicates with the outside of the main body through the opening of the front supporter and is opened and closed by the door 104. [ The user can open the door 104 and insert the laundry into the drum 120 through the front supporter and the openings of the front end of the drum 120. [ In addition, the rear supporter 122 includes a recess, and an inner peripheral surface of the recess rotatably supports an outer peripheral surface of a rear end portion of the drum 120. Thus, the front supporter and rear supporter 122 are stationary while the drum 120 is relatively rotatably supported by these stationary supporters.

Although the structure of the inside of the dryer is not shown in detail in the drawing, the clothes dryer has a blowing fan for circulating the air inside the drum 120. At the lower part of the dryer, And a heat exchanger for condensing moisture contained in the circulating air. The air discharged from the drum 120 flows into the drum 120 again by the blowing fan. At this time, a duct for guiding circulated air and allowing the air discharged from the drum to flow into the drum again is provided. As described above, since the front supporter and the rear supporter 122 are in a fixed state, the suction portion and the discharge portion of the duct can not be connected to the rotating drum 120. Thus, the fixed front supporter and the rear supporter 122 To communicate with the inside of the drum 120. Also, a heater assembly 200 for heating the air introduced into the drum 120 to generate hot air is provided in the duct. The duct may include an intermediate duct 140 and a rear duct 130, as shown in FIG. The intermediate duct 140 may be provided with various accessories such as a heat exchanger and a blower fan as well as the heater assembly 200. FIG. 2 shows only a portion of the middle duct 140 that contains only the heater assembly 200, and a heat exchanger and a blower fan, similar to the heater assembly 200, may be installed in the middle duct 140. The rear duct 130 is connected to the middle duct 140 and is connected to the rear supporter 122 to communicate with the drum 120 again. More specifically, the rear supporter 122 has an opening 123 communicating with the rear end of the opened drum 120, and an end of the rear duct 130 is connected to the opening 123. Accordingly, the rear duct 130 is dried by the heat exchanger in the middle duct 140, and then the air heated by the heater assembly 200 is supplied into the drum 120 through the opening 123. Although not shown, a front duct is connected to the front of the intermediate duct 140, and air in the drum 120 having relatively high humidity and low temperature is sucked by the drying of the laundry. The heater assembly 200 may be a resistance coil heater using electric resistance heat or a burner that generates heat by burning gas. Hereinafter, the case of using the resistance coil heater will be described as an example, but it goes without saying that the embodiment of the present invention can be applied to the burner. Also, while the arrangement of the duct structure and heat exchanger and heater assembly described above has been described on the basis of a condenser dryer, the dryer of the present invention may have a duct structure according to an exhaust dryer and accordingly the arrangement of associated parts. It is understood that the steam generators and related arrangements, which will be described below, can also be applied to an exhaust-type dryer without additional deformation since practically the condenser-type dryer and the exhaust-type dryer are distinguished from each other only in a circulating manner of air.

In FIG. 2, the steam generator according to the first embodiment of the present invention is simplified with other related parts. A drawer 110 is inserted into the drawer 110 so as to be drawn out from the front cover 101 of the dryer body. A cartridge 113 corresponding to a storage tank for storing water is detachably attached to the drawer 110 Respectively. The drawer 110 is installed on the top of the front cover 101 of the dryer and is installed on the side of the control panel 103 on the top of the front cover. The cartridge 113 is provided with a handle 114 and the user can easily detach or mount the cartridge 113 from the drawn drawer 110 using the handle 114. In addition, a heater assembly 200 for heating the air introduced into the drum is provided in the middle duct 140 located under the clothes dryer. A steam generator 230 is provided in the middle duct 140 adjacent to the heater assembly 200 to receive heat from the heater assembly to convert water into steam. The cartridge 113 and the steam generator 230 are connected to each other by a water supply hose 116 and the water supply hose 116 is provided with a pump 115. The water stored in the cartridge 113 is supplied to the steam generator 250 through the water supply hose 116 to be converted into steam and the pump 115 opens and closes the water supply hose 116, Adjust the amount of water supplied to the steam generator. That is, when the pump 115 opens the water supply hose 116 and supplies water to the steam generator 230 at a time when steam is required, water supplied from the steam generator is converted into steam.

In this embodiment, the pump is used to adjust the amount of water supplied to the steam generator 230. However, the present invention is not limited to this, and a valve may be provided in the water supply hose 116 to open / close the hose The amount of water supplied to the steam generator may be adjusted. As shown in FIG. 2, in this embodiment, the cartridge is provided at the left upper portion as viewed from the front of the dryer, and the steam generator is provided at the lower right portion. By utilizing the height difference between the cartridge and the steam generator, The water supplied to the water supply valve may be controlled by a valve.

In FIG. 3, the steam generator 230 according to the first embodiment of the present invention is shown in more detail together with the heater assembly 200. First, the heater assembly 200 basically includes a heating unit, and the heating unit includes a support 201 and a resistance coil 202 wound around the support 201. The support 201 is made of an insulating material for electricity and heat, and the resistance coil 202 generates heat by using electrical resistance. A plurality of such heating units are assembled to form one heater assembly 200. 5, the heater assembly 200 may further have a support plate 203 on which the heating units are fitted. By this support plate 203, the heating units can be more stably fixed in the duct . Inside the duct 140, there is provided a steam generator 230 that receives the heat of the heater assembly 200 and converts water into steam. The steam generator 230 is a long metal tube having a predetermined diameter and is disposed at one side of the heater assembly 200. In this embodiment, the steam generator 230 is arranged in a zigzag form on the upper side of the heater assembly 200. However, the shape in which the steam generator is disposed is not limited thereto, and may be arranged in a staggered shape on the upper side and both side surfaces of the heater assembly 200. In addition, the steam generator made of the metal tube is advantageously made of a copper tube on the heat transfer surface.

 At both ends of the steam generator 230, an inlet 231 and an outlet 232 protruding from the duct are provided. The inlet 231 is a passage through which the water from the cartridge 113 flows into the steam generator, and the outlet 232 is a passage through which steam generated from the steam generator is discharged. A water hose 116 is connected to the inlet so that the water stored in the cartridge 113 flows into the steam generator and the steam hose 117 is connected to the outlet 232 to discharge steam generated in the steam generator It goes out. The steam hose 117 is preferably made of a metal pipe considering the temperature of the steam flowing into the steam hose 117. The steam generator 230 indirectly receives heat generated by the heater assembly through convection through the air or directly through radiation to heat water stored in the heater assembly 230 into steam. As mentioned above, since the steam generator 230 is a small-diameter metal pipe, the amount of water flowing is small. Further, since the steam generator 230 is disposed in a zigzag manner, it has a considerably wide heat transfer area. Therefore, a small amount of water flowing in the steam generator 230 can be quickly heated and converted into steam. The steam generator is preferably made of a copper tube or an aluminum tube to increase the heat transfer coefficient.

A nozzle 118 is provided at an end of the steam hose 117 to inject steam into the drum 120. The nozzle 118 may be installed in a rear supporter 122 that supports the drum 120 at a rear end, as shown in FIG. The steam flowing in the steam hose 117 can be condensed on the inner wall of the steam hose 117 when the temperature is lowered. In order to prevent this, the steam hose 117 is preferably installed near the outer wall of the rear duct 130, which is a passage through which hot air heated by the heater flows into the drum. Preferably, the steam hose 117 is attached to the rear duct 130, so that the steam hose 117 can receive high-temperature heat from the rear duct 130. Further, in order to prevent internal condensation by receiving the heat of the rear duct, it is preferable that the steam hose is manufactured in the form of a metal pipe having a good heat transfer coefficient. The nozzle 118 provided at the end of the steam hose 117 is installed in the rear supporter 122 for supporting the rear surface of the dryer drum 120 and the rear end of the drum 120 is opened Steam is injected into the drum.

4 shows another embodiment in which the nozzle 118 is installed. In FIG. 4, the steam hose 117 is installed in close contact with the rear duct 130 to prevent condensation of steam passing through the steam hose 117. The nozzle 118 is installed on the upper side of the rear duct 130, and the nozzle is installed near an inlet, that is, an opening 123 through which hot air flows into the drum. With this configuration, the steam hose 117 and the nozzle 118 can continuously receive heat from the rear duct 130, thereby preventing the steam inside the steam hose from being condensed during the flow of the steam .

FIG. 5 is a perspective view showing a second embodiment of the steam generator, and FIG. 6 is a partial perspective view showing the steam generator according to the second embodiment in more detail. The second embodiment of the steam generator will be described in detail with reference to these drawings.

3 and 6, air in the middle duct 140 flows into the front of the heater assembly 200 and flows through the heater assembly 200 while passing through the heater assembly 200. [ And is sequentially heated by the heating units. Thereafter, the heated air is discharged from the rear of the heater assembly 200. Considering this heating process, the air that has not been heated yet absorbs more heat from the front portion of the heater assembly 200 than the rear portion of the heater assembly 200. Thus, the rear portion of the heater assembly 200 has more heat that can be used for relatively heating. On the other hand, since heating of the air is actually completed at the rear portion of the heater assembly 200, the air in the rear portion has a significantly higher temperature than the air in the front portion. Thus, the air in the rear portion has more heat energy to heat the other object than the air in the front portion. For this reason, the rear portion of the heater assembly 200, i.e., the air discharge portion, has a high ability to indirectly supply heat energy to the steam generators 220 and 230 by convection using air having a high temperature around the heater assembly 200, Lt; RTI ID = 0.0 > 200, < / RTI > Accordingly, the steam generator 330 according to the second embodiment is configured to be disposed only around the rear portion of the heater assembly 200, that is, around the air discharge portion. The steam generator 330 according to the second embodiment can efficiently and efficiently generate steam by utilizing the high heating capability of the rear portion (discharge portion) of the heater assembly. In addition, as compared to the steam generator 220 of the first embodiment which extends over the entire heater assembly 200, the steam generator 330 has a simpler and easier-to-manufacture structure, Productivity can be increased.

Further, the steam generator 330 may be configured to surround the heater assembly 200 so as to have a higher heating efficiency. 6, the steam generator 330 basically includes a first generator 331 disposed at an upper portion of a rear portion (i.e., a discharge portion) of the heater assembly 200, . That is, the first generator 331 is disposed at a predetermined distance from the upper surface of the rear portion (discharge portion). Also, the steam generator 330 may have a second generator 332 disposed under the rear portion (discharge portion) of the heater assembly 200. In other words, the second generator 332 is disposed at a predetermined distance from the lower surface of the rear portion (discharge portion). These first and second generators 331 and 332 can greatly increase the heating efficiency by using both the top and bottom portions of the rear portion of the heater assembly having the greatest heating capability. The steam generator 330 may have a third generator 333 that connects the first generator and the second generator 331 and 332 and is disposed adjacent to the side of the rear portion of the heater assembly 200 . The third generator 333 may be disposed adjacent to the left or right portion of the rear portion of the heater assembly 200. However, it is preferable to arrange the third generator 333 adjacent to the side, i.e., the rear end of the rear portion (discharge portion) of the heater assembly in which the highest temperature air is directly discharged as shown in the drawing, More advantageous. The steam generators 330, that is, the first to third generators 331, 332 and 333 are formed of metal tubes which are zigzag in parallel to the surface of the heater assembly 200 facing each other as in the first embodiment described above. Accordingly, when water is supplied through the inlet port 335, the water is immediately converted into steam while passing through the first to third generators 331 to 333, and is discharged through the outlet port 336.

In consideration of the above description, the steam generators 330 enclose a portion having the highest heating capability of the heater assembly 200 while increasing the heat transfer area by the first to third generators 331, 332, 333. For this reason, the heating efficiency of the stem generator 330 according to the second embodiment is maximized.

Like the steam generator 220 of the first embodiment, the outlet 336 protrudes out of the duct and the steam hose 117 can be connected to the outlet 336 together with the nozzle 118. Therefore, Steam can be supplied into the drum 120 through the steam hose 117 and the nozzle 118. [ However, as already described above, since the steam hose 117 is exposed to the outside of the duct, the temperature is lowered and the steam is condensed, and the amount and quality of the steam may be deteriorated. Therefore, as shown in FIG. 5, the steam generator 220 according to the second embodiment may further include a subsidiary generator 334. The auxiliary generator 334 is connected to the steam generator 320, or to the outlet 336, and is disposed in the duct, i.e., the rear duct 130. More particularly, the auxiliary generator 334 extends away from the heater assembly 200 along the flow direction of the heated air discharged from the heater assembly 200. That is, the auxiliary generator 334 further extends from the steam generator 330 along the rear duct 130 and also extends toward the drum 210, precisely the outlet of the duct communicating with the drum 210 Lt; / RTI > The auxiliary generator 334 may be formed of a metal tube as in the case of the first-third generator, and may extend in a straight line in the drawing, but may be zigzag bent to increase the heat transfer area. The steam discharged from the steam generator 330 is reheated by the hot air flowing in the duct while passing through the auxiliary generator 334, and is not condensed. Thus, the amount and quality of steam actually supplied to the drum 120 by this auxiliary generator 334 can be greatly increased.

5, the end of the auxiliary generator 334 may extend outwardly through the rear duct 130, and an outlet 337 may be formed at the end of the auxiliary generator 334 to discharge the steam. have. In this case, the steam hose 117 may be connected as in the steam generator 220 of the first embodiment, and the nozzle 118 is provided at the end of the steam hose 117. 2, the nozzle 118 may be installed on the rear supporter 122 that rotatably supports the rear end of the drum 120, or may be installed on the rear duct 122 adjacent to the opening 123 of the rear supporter, (130), and more preferably, at a portion communicating with the drum of the rear duct (130). 5, the auxiliary generator 334 itself does not protrude out of the duct, and the auxiliary generator 334 itself does not protrude along the rear duct 130 from the outlet of the duct communicating with the drum That is, to the opening 123. In this case, the nozzle 118 may be mounted at the end of the auxiliary generator 334 to inject steam into the drum at the outlet.

Like the steam generator 220 of the first embodiment, the inlet 335 is connected to the water supply hose (not shown) so that water is introduced into the steam generator from the cartridge 113, which is detachably attached to the drawer 110 116). Also, the steam generator 330 may be formed of an aluminum pipe or a copper pipe.

Hereinafter, a control method of the dryer having the above-described steam generator will be described. The dryer control method is described below with reference to a condensing dryer, but can be applied directly to an exhaust dryer without further modification.

FIG. 7 is a flowchart showing a control method of a dryer according to the present invention, and FIG. 8 is a graph illustrating water supply to a steam generator in a steam supply step of a control method according to the present invention.

Before performing the drying of the laundry, the laundry is first introduced into the dryer (S10). The user first opens the door 104 of the dryer and then opens the drum 104 through the front cover 101, the front supporter (not shown) and the front end of the drum 120, 120 to be dried.

After the laundry is put into the drum 120, the user instructs the dryer to use a desired drying course using the control panel 103. In this instruction process, the user generally selects and instructs a drying course including a steam supply for better drying of the laundry. However, in order to shorten the time required for drying the laundry, It is also possible to select and instruct the drying course. When the drying course selected by this instruction is started, hot air is supplied into the drum 120 (S20). In the supplying step S20, the air inside the drum 120 is sucked into the duct by the blowing fan, and is heated by the heater assembly 200 disposed inside the duct. Thereafter, the generated hot air is guided by the duct to be supplied into the drum 120, and the laundry is dried. When the heat exchanger is installed inside the duct, the heat exchanger removes moisture from the air sucked into the duct by heat exchange to make dry air more suitable for drying the laundry before heating the air. In addition, the drum 120 is rotated together with the supply of the hot air. By the rotation of the drum 120, the laundry is mixed and exposed evenly to the supplied hot air, so that the laundry can be dried more easily.

Through the hot air supply step (S20), the laundry can be dried, but there are still many wrinkles in the dried laundry. Therefore, after completion of the supplying step S20, a predetermined amount of steam is supplied into the drum 120 (S30).

In the steam supply step S30, water may be continuously supplied to the steam generators 230 and 330 to generate steam. Preferably, in the control method of the present invention, water is intermittently supplied to the steam generators 230 and 330 (S32). This intermittent supply step S32 is shown more specifically in Fig. In the graph of FIG. 8, the change in the heater assembly power supply with respect to time is indicated by a solid line, and the change in the voltage of the thermister installed in the heater assembly with respect to time is indicated by a dotted line. 8 shows a change in the temperature of the heater assembly 200. The change in the voltage of the thermistor voltage in FIG. Thus, as shown in FIG. 8, the temperature of the heater assembly 200 (i.e., the power of the thermistor to be output (i.e., the power of the output thermistor) during operation of the heater assembly 200 Value) is increased.

When the pump 115 is operated, water is supplied from the storage joining cartridge 113 to the steam generators 230 and 330 through the water supply hose 116, as described above with reference to the steam generators 230 and 330. [ The supplied water is converted into steam by passing through the zigzag bent metal pipe of the steam generator 230, 330. However, if water is continuously supplied to the steam generators 230 and 330, all the supplied water may not be converted into steam. That is, a part of the supplied water is directly discharged from the steam generator 230, 330. The discharged water may condense a part of the steam discharged together to lower the amount and quality of steam supplied into the drum 120. In addition, the discharged water may block the supply of steam by blocking the supply line, and may be supplied directly into the drum 120 to dry the laundry. Therefore, it is preferable that water is intermittently supplied to the steam generators 230 and 330 according to the intermittent supply step S32 so that only an appropriate amount of water is supplied to the steam generators 230 and 330. [

In the graph of FIG. 8, the period of the intermittent water supply step S32 is represented by a plurality of horizontal bars, and the lower part of FIG. 8 shows the operation waveform of the pump 115 in one of the water supply periods. That is, when the value of the operation waveform is "1 ", the pump 115 is activated, and when the value is" 0 ", the pump 115 is stopped. As shown in the above operation waveform, the intermittent water supply step S32 consists substantially of operating the pump 115 intermittently. Further, as described above, a valve may be applied instead of the pump 115, and in this case, the valve is intermittently opened in the intermittent water supply step S32.

8, the intermittent supplying step S32 is a step of supplying water to the steam generators 230 and 330 for a predetermined time, and after the supplying step A, And stopping the supply of water for a predetermined period (B). Also, the feeding step (A) and the stopping step (B) are repeatedly and alternately performed, as shown by the operating waveforms. As described above, the period of the supplying step (A) is set to be shorter than the period of the stopping step (B) in order to supply only an appropriate amount of water so as to be changed into steam in the steam generators 230 and 330. Preferably, the period of the stopping step (B) is set to nine times the period of the supplying step (A). That is, the period of the supplying step (A) corresponds to 1/9 of the period of the stopping step (B). Actually, the feeding step (A) is performed for 0.1 second, and the stopping step (B) is performed for 0.9 second.

On the other hand, in order to switch the steam to a small amount of water supplied by the intermittent supply step S32, sufficient heat must be supplied from the heater assembly 200. Therefore, it is preferable that the intermittent supplying step S32 is performed during the operation of the heater assembly 200. The graph of FIG. 8 also shows that the intermittent supply step S32 indicated by the horizontal bar is performed only while power is supplied to the heater assembly 200. Actually, the intermittent supplying step S32 is performed between the temperature of 62 ° C and 66 ° C of the heater assembly 200 while the heater assembly 200 is operated to receive sufficient heat. Referring to the graph of FIG. 8, as shown by the voltage change of the thermistor in the interval from the time 0 minute to about 3 minutes, a predetermined time (about 1 minute) after the heater assembly 200 starts to operate for the first time, The actual temperature of the heater assembly 200 (i.e., the voltage value of the thermistor) starts to rise. In addition, after a predetermined time has elapsed after the temperature of the heater assembly 200 starts to rise, the temperature reaches a proper temperature for heating the supplied water. Therefore, if water is supplied immediately after the heater assembly 200 starts to operate for the first time, the water is hardly converted into steam in the heater assemblies 230 and 330, and water can be discharged as it is. For this reason, it is preferable that the first intermittent supply step S32 is started when a predetermined time elapses after the heater assembly is first started to operate, as indicated by a point "C" Actually, the initial intermittent supply step S32 may be started at a heater assembly temperature of 53 deg. C, about two minutes after the heater assembly 200 is first activated. That is, the point "C" at the beginning of the first intermittent supply step S32 corresponds to about 2 minutes after the operation of the heater assembly 200 for the first time and the temperature of the heater assembly 53 degrees Celsius.

On the other hand, since the steam supply step S30 is not an intended stage for supplying hot air, it is required that the heater assembly 200 maintains an appropriate temperature suitable for steam generation. If the heater assembly 200 is continuously operated at a high temperature, it results in unnecessary power consumption. Accordingly, the heater assembly 200 may preferably be operated intermittently (S31). That is, in the intermittently operating step S31, the heater assembly 200 is stopped for a predetermined time after being operated for a predetermined time, and the operation and the stopping process are alternately repeated. Such an intermittent operation step S31 is apparent from the power supply change of the heater assembly with respect to time in the graph of Fig. Therefore, when the intermittent heater assembly operation step S31 is applied, the heater assembly 200 is intermittently operated in the operation step S31 and the subsequent intermittent water supply step S32, And is intermittently supplied to the steam generators 230 and 330 while the heater assembly 200 is operated. The graph of FIG. 8 also shows that the intermittent feeding step S32 indicated by the horizontal bar is performed only while the electric power is supplied to the heater assembly 200 in the intermittent operation of the heater assembly 200. Therefore, according to the combination of the intermittent operation and the supply (S31, S32), a sufficient amount of steam can be generated while minimizing waste of energy.

After completion of the intermittent supply step S32, the steam generators 220 and 230 heat the supplied water (S33). In the heating step S33, as described above, the supplied water is continuously bent in a zigzag manner to continuously flow in the steam generators 230 and 330 made of a metal tube having a wide heat transfer area. During this flow, the supplied water is directly heated by thermal energy radiation from the heater assembly 200. Simultaneously, the supplied water is indirectly heated by convection using air having a high temperature around the heater assembly 200. In the heating step S33, the supplied water is converted into steam. Particularly, only a small amount of water is supplied in accordance with the intermittent supplying step S32 described above, and the supplied water is heated to a high temperature all at once by using the entire wide heat transfer area in the steam generators 230 and 330 which are bent metal tubes. For this reason, the supplied small amount of water is instantaneously converted to steam all at once. Accordingly, the steam generator 230 or 330 can generate a high quality steam and a large amount of steam in a short period of time without discharging water. In addition, the heat of the heater assembly 200 is basically used, and the heater assembly 200 is intermittently operated to maintain only an appropriate heating temperature, so that steam can be generated using only a small amount of energy.

The steam generated by the heating step S33 is supplied into the drum 120 through various methods as described in the first and second embodiments of the steam generator 230 and 330 of Figs. 2-6 (S30 ). The supplying step S30 including each of the above steps S31-S33 can be performed for practically 30 minutes to supply sufficient steam to the drum 120. [ In addition, the drum 120 may be rotated together with the supply of the steam. The laundry is mixed by the rotation of the drum 120, and can be uniformly exposed to the supplied steam. The steam supplied in the supplying step S30 removes the wrinkles of the basically dried laundry and also removes the static electricity. In addition, since the temperature of the steam is high, the odor of the laundry dried by the provided steam can be removed and sterilized. Therefore, the dried laundry can be refreshed in a state suitable for the user to wear immediately.

On the other hand, the laundry may be slightly wetted by the supply of the steam. Therefore, in order to dry such laundry, hot air can be supplied to the drum 120 after the steam supply step S30 (S40). Since the dryer operation in the secondary supplying step S40 is substantially the same as the primary supplying step S20 mentioned above, a further explanation will be omitted. However, since the secondary supplying step S40 is for removing only a very small amount of water by steam supply, it is performed only for a short time, and may be omitted if necessary.

After completion of the secondary supplying step S40, the interior of the drum 120 is cooled (S50). The drum 120 itself and the inner space are heated to a high temperature together with the laundry by the supplying steps S20, S30, and S40 performed previously. Therefore, during the removal of the dried laundry, the user may be burned by the hot laundry or the drum 120 or the like. For this reason, in the cooling step (S50), only the air blowing fan is operated so that air of relatively low temperature is continuously supplied into the drum (120). Further, the drum 120 may be rotated during the cooling step S50 to increase the cooling efficiency. Accordingly, the drum 120 and the laundry are cooled to a proper temperature, and after the predetermined time, the cooling step S50 is completed, thereby ending the entire drying course. Thus, the user can remove the dried laundry from the dryer without the risk of harmfulness, and can immediately wear the refreshed laundry without wrinkles, if necessary. In addition, if the water stored in the cartridge 113 is consumed after the dryer performs a plurality of drying courses, the user draws the drawer 110 for the next drying course and then draws water on the cartridge 113 It can be supplemented by pouring.

In the embodiments of the steam generators 230 and 330 according to the present invention described above, steam is generated by using the heat of the heater assembly 200, so that a separate heater for generating steam is not required. Also, for the same reason, the steam generators 230 and 330 according to the above-described embodiments, compared to the conventional steam generators, have a fairly simple structure and can be easily manufactured. Therefore, the manufacturing cost of the steam generator of the present invention is reduced, and the productivity is increased. Also, the use of energy for generating steam is reduced.

In addition, since only an appropriate amount of water is supplied to the steam generators 230 and 330 by the intermittent supply in the control method according to the present invention, all the instantaneous supplied water can be converted into steam. In addition, the control method uses a heater assembly 200 for generating hot air without a separate heater for generating steam, and further intermittently operates such a heater assembly 200 to maintain only an appropriate temperature for steam. Therefore, by the control method, high-quality steam can be supplied to the drum 120 in a short time, and the energy required for such steam generation can be reduced.

1 is a perspective view showing a dryer having a steam generator according to the present invention;

2 is a perspective view showing a first embodiment of the steam generator;

3 is a partial perspective view showing the steam generator according to the first embodiment in more detail;

4 is a partial perspective view showing a modification of the steam generator according to the first embodiment;

5 is a perspective view showing a second embodiment of the steam generator;

6 is a partial perspective view showing the steam generator according to the second embodiment in more detail;

7 is a flowchart showing a control method of a dryer according to the present invention; And

8 is a graph for explaining the water supply to the steam generator in the steam supply step of the control method according to the present invention.

Claims (8)

Placing the laundry to be dried into the drum of the dryer; Supplying hot air heated by the heater assembly in the drum to dry the laundry; And And supplying steam generated by a steam generator disposed around the heater assembly to provide a flow path for water to the drum, The steam supply step may include: Intermittently supplying water to the steam generator while the heater assembly is operating; And And heating the water supplied by the steam generator using heat generated from the heater assembly, Wherein the intermittent supply step comprises intermittently driving a pump connected to a reservoir for storing a predetermined amount of water. The method according to claim 1, Wherein the steam supply step further comprises intermittently operating the heater assembly before the intermittent supply step. delete The method according to claim 1, Wherein the intermittent supply step comprises intermittently opening a valve connected to a reservoir for storing a predetermined amount of water. The method according to claim 1, Wherein the intermittent supplying step comprises supplying water to the steam generator for a predetermined time and stopping supply of water for a predetermined time after the supplying step, wherein the supplying step and the stopping step are alternately repeatedly performed And a control unit for controlling the drying unit. 6. The method of claim 5, Wherein the period of the stopping step is nine times the period of the supplying step. 6. The method of claim 5, Wherein the supplying step is performed for 0.1 second, and the stopping step is performed for 0.9 second. The method according to claim 1, Wherein said intermittent feeding step is operated between a heater assembly temperature of 62 [deg.] C and 66 [deg.] C.

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