KR100820151B1 - Ductless dryer - Google Patents

Abstract

A ductless dryer is provided to keep a room quiet by reducing noise which is transmitted through a vent duct exposed. A ductless dryer comprises a body, a drum, a heat exchanging unit(150), a circulating duct(114), a vent duct(181), and a muffler(160). The drum rotates on the body. The heat exchanging unit removes moisture from air discharged from the drum. The circulating duct guides the discharged air to the heat exchanging unit. The vent duct guides air from the heat exchanging unit to the outside. The muffler which is installed between the circulation duct and the heat exchanging unit reduces noise transmitted through the vent duct. The muffler is aligned on the same line as the heat exchanging unit.

Description

Ductless Dryer {DUCTLESS DRYER}

1 is a view schematically showing a ductless dryer having a muffler according to a first embodiment of the present invention;

2 is a plan view showing the interior of the ductless dryer of Figure 1,

3 is a view for measuring the noise of the ductless dryer to design the muffler of FIG.

4 is a graph showing the noise measurement result of FIG.

5 is a view for measuring the noise transmitted through the exhaust duct of the ductless dryer to design the muffler of FIG.

6 is a graph illustrating a noise measurement result of FIG. 5;

7 is a view showing the muffler of FIG.

FIG. 8 is a graph comparing noises when the muffler of FIG. 7 is mounted and not mounted; FIG.

9 is a view showing a muffler according to a second embodiment of the present invention;

10 is a cross-sectional view VII-VII of FIG. 9,

FIG. 11 is a view showing a cross-section VI-XI of FIG. 9;

FIG. 12 is a graph illustrating a comparison of noise measurement results according to changes in the number of muffler exhaust holes in FIG. 9.

<Explanation of symbols for the main parts of the drawings>

110: main body 111: door

113: foot 114: circular duct

120: drum 131: belt

133: fan 135: motor

140: hot air supply unit 141: valve

143: gas burner 145: hot air supply duct

150: heat exchanger 151: fin

153: tube 160: muffler

161: Hall 1 163: Hall 2

165: Hall 3 170: Muffler

171: inner tube 171a: sound hole

173: appearance 173a: outer wall

173b: inner wall 181: exhaust duct

S: Noise Space

The present invention relates to a ductless dryer with reduced noise, and more particularly, to a ductless dryer with reduced overall noise by reducing noise transmitted through an exhaust duct exposed to a room.

In general, a clothes dryer is a device that blows hot air generated by a heater into a drum to absorb moisture of a drying object and to dry the drying object. Treatment of wet air generated by drying a drying object by absorbing moisture According to the method, it is classified into exhaust type clothes dryer and condensation clothes dryer.

Exhaust type clothes dryer uses a method of exhausting the humid air discharged from the drum to the outside of the dryer. However, an exhaust duct for exhausting the vaporized water in the drum to the outside is required, and in particular, since the combustion product carbon monoxide and the like are exhausted, there is a disadvantage in that the exhaust duct must be extended to be installed outside.

On the other hand, the condensation type clothes dryer uses a method of condensing the humid air exhausted from the drum in the heat exchanger to remove moisture, and then sending dry air from which the moisture is removed back to the drum to recycle. However, it is not easy to use gas as a heat source because dry flow forms a closed loop.

The ductless dryer is a dryer that overcomes the disadvantages of the exhaust type clothes dryer and the condensation type clothes dryer. That is, the ductless dryer can be maintained at low cost by using gas as a heat source, and there is an advantage of not having to install a separate exhaust duct extending to the outside.

However, in the case of a ductless dryer, the exhaust duct is exposed to the room, and noise is emitted to the room through the exhaust duct. For this reason, there is a problem that it is difficult to create a quiet indoor environment.

An object of the present invention is to provide a ductless dryer with reduced noise. In addition, another object is to provide a ductless dryer with reduced noise transmitted through an exhaust duct exposed to the room.

Ductless dryer according to the present invention for achieving the above object, the main body; A drum rotatably installed on the main body; A heat exchanger for removing moisture contained in the air exhausted from the drum; A circulation duct for directing air exhausted from the drum to the heat exchange unit; An exhaust duct for guiding air exhausted from the heat exchanger to the outside; It includes; a muffler for reducing the noise transmitted through the exhaust duct.

Here, the muffler is preferably installed between the circulation duct and the heat exchange part due to the limitation of space. In addition, the muffler is preferably connected in a straight line with the heat exchanger so that the air exiting the muffler flows directly into the heat exchanger. The muffler described above is formed by sequentially connecting the first, second and third pipes, and the cross-sectional area of the second pipe is preferably larger than the cross-sectional areas of the remaining first and third pipes.

Here, it is more preferable that the cross-sectional areas of the first pipe and the third pipe are the same.

In addition, the noise transfer loss (L _T ) of the muffler is preferably determined by the following equation.

Where, I: sound A ₁ in the second tube outlets: the first tube, the third tube cross-sectional area A ₂ of _the: second tube cross-section l of: Noise T in the second tube inlet of the second pipe length c: speed of sound f: frequency n = 1, 2, 3 ... f ₁ : target noise frequency (when n = 1)

On the other hand, the muffler, the inner tube; And an external appearance surrounding the inner tube to form a noise space. The surface of the inner tube may be configured to have a plurality of noise holes communicating with the noise space. Here, it is preferable that the exterior wraps all or part of the inner tube, and if it wraps a part, it is preferable that an angle θ of the outer tube partially wraps the inner tube is 120 ° or less.

Here, the outer side, the outer wall surrounding the inner tube in a radial direction away from; And side walls blocking the front and rear of the outer wall to form the noise space. In addition, the target noise frequency to be reduced through the muffler is preferably determined by the following equation.

Where p is the area percentage occupied by the noise hole in the area of the inner tube forming the floor of the noise space

l: separation distance from inner tube to outer tube

t: thickness of inner tube

d: diameter of sound hole

f _res : Target noise frequency

Hereinafter, a ductless dryer having a muffler according to a first embodiment of the present invention will be described in detail. 1 is a view schematically showing a ductless dryer having a muffler according to a first embodiment of the present invention, Figure 2 is a plan view showing the interior of the ductless dryer of FIG. Solid arrows indicate the flow of air.

1 and 2, a ductless dryer having a muffler according to a first embodiment of the present invention includes a main body 110; A drum 120 rotatably installed in the main body 110; Hot air supply unit 140 for providing hot air into the drum 120; A heat exchange part 150 for removing moisture contained in the air exhausted from the drum 120; A circulation duct 114 for guiding air exhausted from the drum 120 to the heat exchange unit 150; An exhaust duct 181 for guiding air exhausted from the heat exchange unit 150 to the outside; And a muffler 160 that reduces noise transmitted through the exhaust duct 181. Here, the muffler 160 is installed between the circulation duct 114 and the heat exchange unit 150 in the constraint of the space. In addition, the muffler 160 is connected in a straight line with the heat exchanger 150 so that the air exiting the muffler 160 flows directly into the heat exchanger 150 in a state where the resistance is minimized.

A door 111 for injecting clothes into the drum 120 is installed on the front surface of the main body 110, and a foot 113 for supporting the main body 110 is installed below the main body 110. Inside the main body 110, a belt 131 for rotating the drum 120, a fan 133 installed in the circulation duct 114 for providing a blowing force of air in the ductless dryer, and the belt 131 and the fan ( A motor 135 providing a driving force to the 133 is installed. Here, a plurality of motors 135 may be configured to provide driving force to the belt 131 and the fan 133, respectively. On the other hand, the circulation duct 114 is provided with a filter (not shown) for filtering lint (Lint), such as lint or seams contained in the air of high temperature and high humidity exiting from the drum 120.

The drum 120 is a barrel having an inner space to allow the clothes to be dried, etc. to be inserted therein, and a plurality of lifters 121 are installed therein to lift the clothes.

The hot air supply unit 140 is a valve 141 for supplying and blocking gas and a gas burner 143 for generating hot air by mixing the gas exhausted from the valve 141 with air provided from the outside, and generated It includes a hot air supply duct 145 connecting the gas burner 143 and the drum 120 so that hot air is supplied to the drum 120. The hot air supply unit 140 may be provided with a flame rod extending to the edge of the flame in order to detect the flame current and indirectly determine the amount of carbon monoxide (CO) through the value of the flame current.

The valve 141 is preferably to use a solenoid valve so that the gas injection amount can be sensitively adjusted.

The gas combustor 143 is connected to the valve 141 and mixes and combusts the gas exhausted from the valve 141 with external air to heat the air with heat generated at this time. The hot air generated by heating is provided to the drum 120 through the hot air supply duct 145.

The heat exchanger 150 is composed of a fin 151 and a tube 153, and condenses the hot and humid air exiting the drum 120 by cold water to make it dry by condensing it with cold water. . The inlet of the heat exchange part 150 is connected to the drum 120 by the circulation duct 114, and the outlet thereof is connected to the exhaust duct 181.

The pin 151 is a thin metal plate having excellent conductivity, and the plurality of thin plates are stacked such that the plurality of thin plates contact and pass vertically with hot and humid air at minute intervals from each other.

The tube 153 has a low temperature (22 ° C.) of water circulating therein, and passes through the fin 151 in a reciprocating manner. Both ends of the tube 153 have a water hose (not shown) for supplying and recovering low temperature water. ) Is connected. The lower part of the heat exchange part 150 is provided with a drip tray (not shown) which collects condensed water that is generated during the condensation process and falls.

3 is a diagram measuring noise of the ductless dryer to design the muffler of FIG. 1, FIG. 4 is a graph showing the noise measurement result of FIG. 3, and FIG. 5 is a ductless dryer to design the muffler of FIG. FIG. 6 is a diagram illustrating a noise transmitted through an exhaust duct of FIG. 6. FIG. 6 is a graph illustrating a noise measurement result of FIG. 5 and a diagram illustrating a muffler of FIG. 1. FIG. 8 is a graph comparing noises when the muffler is attached to and unmounted in FIG. 7, and dashed arrows indicate movement of the noise.

Referring to FIG. 3, the noise of the ductless dryer is measured by placing the microphone at a position 1 m away from the rear side of the ductless dryer. Referring to FIG. 4, the noise measurement results indicate that the noise of the ductless dryer is the loudest of the components around 250 Hz. (Circle portion)

Referring to FIG. 5, a noise is transmitted through the exhaust duct 181 by measuring the microphone at a position 0.1 m away from the exhaust duct 181. Referring to FIG. 6, the noise transmitted through the exhaust duct 181 shows that the noise of the component around 250 Hz is the greatest (circular portion).

4 and 6, it can be seen that the frequency component of the ductless dryer noise and the frequency component of the noise transmitted through the exhaust duct 181 are almost similar. It can be seen that by reducing the noise of the ductless dryer can also be reduced. That is, in order to reduce both the noise of the ductless dryer and the noise transmitted through the exhaust duct 181, the noise of the 250 Hz component transmitted through the exhaust duct 181 may be reduced.

Referring to FIG. 7, the muffler 160 designed to reflect this conclusion is formed by sequentially connecting the first pipe 161, the second pipe 163, and the third pipe 165, and the second pipe 165. ) the cross-sectional area (a ₂₎ is greater than the cross-sectional area (a ₃₎ of the cross-sectional area (a ₁₎ and the third tube 165 of the first tube (161). And, the cross-sectional area of the first tube (161) (A ₁₎ and the third cross-sectional area of the tube (165) (A ₃₎ is the same. Thus, the muffler 160, which has a different cross-sectional area of the pipe, has different acoustic impedances, thereby preventing the sound of the frequency component according to the characteristic of the length from passing through well.

On the other hand, the noise transfer loss (L _T ) of the muffler 16 described above is determined by the following equation. The larger the noise transmission loss (L _T ), the less the noise transmitted through the exhaust duct 181.

[ first  expression]

[ second  expression]

Where, I: Noise and T in the second tube inlet: sound A ₁ in the second outlet comprising: a first tube, the cross-sectional area A of the third tube _2: cross-sectional area of the second tube c: speed of sound f: frequency n = 1, 2, 3 ... f ₁ : Target noise frequency (when n = 1).

When the target noise frequency f ₁ to be reduced by 250 is set to 250 Hz, the length l of the second pipe 163 is calculated to be 334.6 mm by the second equation. Also, considering the installation location and size of the muffler 160 in the ductless dryer, the cross-sectional areas A ₁ and A _2: are adjusted to an appropriate size to calculate the maximum noise transfer loss (L _T ) by the first equation. As a result, the diameter d1 of the 1st pipe | tube 161 and the 3rd pipe | tube 165 is calculated as 100 mm, and the 2nd pipe | tube 163 is calculated as 140 mm.

In summary, when the target noise frequency f ₁ is set to 250 Hz, the length l of the second pipe 163 is 334.6 mm, and the diameter d1 of the first pipe 161 and the third pipe 165 is 100 mm. , The second pipe 163 is calculated to be 140mm.

Referring to FIG. 8, as a result of mounting the designed muffler 160 to the ductless dryer, it can be seen that noise near 250 Hz is greatly reduced by 10 dB or more.

In conclusion, due to the muffler 160, the noise transmitted through the exhaust duct 181 exposed to the room is reduced and at the same time the noise of the entire ductless dryer is reduced to create a quiet indoor environment.

9 is a view showing a muffler according to a second embodiment of the present invention, FIG. 10 is a view showing the cross-sectional view VII-X of FIG. 9, FIG. 9 is a graph illustrating a comparison of noise measurement results according to changes in the number of muffler exhaust holes in FIG. 9.

9 and 10, the muffler 170 according to the second embodiment of the present invention includes an inner tube 171; And an exterior 173 which surrounds part or all of the inner tube 171 to form a noise space S. On the surface of the inner tube 171, a plurality of noise holes 171a communicating with the noise space S are drilled.

The exterior 173 preferably wraps all or part of the inner tube 171 in order to increase the noise reduction effect. As in the second embodiment, when the exterior 173 partially covers the inner tube 171, the wrapping angle θ is preferably 120 ° or less.

To this end, the exterior 173 includes: an outer wall 173a surrounding the inner tube 171 in a radial direction away from each other; And sidewalls 173b that block the front and rear of the outer wall 173a to form a closed noise space S.

On the other hand, the target noise frequency to be reduced by the muffler 170 described above is determined by the following equation.

[ third  expression]

Where p is the area percentage occupied by the noise hole in the area of the inner tube forming the floor of the noise space, l is the distance from the inner tube to the exterior, t is the thickness of the inner tube, d is the diameter of the noise hole, and f _res : Target noise frequency.

By the third expression as described above, the target noise frequency f _res to be reduced is set to 254 Hz, and l is 50 mm, t is 3 mm, and d is 7 mm in consideration of the installation position and size of the muffler 170 in the ductless dryer. When set, p is calculated as 1.1%.

Alternatively, by setting the target noise frequency f _res to be reduced by the third equation as described above, 179 Hz, l is 50 mm, t is 3 mm, and d is 7 mm in consideration of the installation position and size of the muffler 170 in the ductless dryer. P is calculated as 0.55%.

Here, it can be seen that the target noise frequency f _res to the time when setting the 254Hz, a target noise frequency f _res drilled a noise ball (171a) tightly than when set to 179Hz in the surface of the inner tube 171. Of course, in the state where the target noise frequency is set, the number of noise holes 171a may be determined and the remaining variables l, d, and t may be adjusted.

9 and 12, when the spurs are placed at the inlet of the muffler 170 designed as described above, and the input noise (swept sinusoidal signal) of 2 Hz to 1200 Hz is applied from the speaker, the muffler 170 is input to the input noise. The micromeasurement of noise at the exit of

In the muffler 170, where the target noise frequency F254 (f _res is 254 Hz), l is 50 mm, t is 3 mm, d is 7 mm, and p is 1.1%, the noise reduction is large around 254 Hz, and the target noise frequency F179 (f _res 179 Hz), l is 50mm, t is 3mm, d is 7mm, p is 0.55% in the muffler 170, it can be seen that the noise reduction is large around 179Hz. In other words, the noise hole 171a acts as if it is a regulator to absorb the target noise frequency component set to prevent it from being discharged out.

In conclusion, due to the muffler 170, the noise transmitted through the exhaust duct 181 exposed to the room is reduced and at the same time the noise of the entire ductless dryer is reduced to create a quiet indoor environment.

The operation of the exhaust ductless dryer according to the first embodiment will be described below.

1 and 2, after the gas is supplied from the valve 141, the gas burner 143 is mixed with external air and then ignited to generate hot air. The generated hot air is supplied into the drum 120 through the hot air supply duct 145. Drying objects such as clothes accommodated in the drum 120 are dried by the supplied hot air.

High-temperature, humid air by drying the drying object is exhausted from the high-temperature, humid air through the circulation duct 114. Lint, such as lint or seams, contained in the high temperature and humid air exhausted from the drum 11 is collected and removed while passing through a filter (not shown) installed on the circulation duct 114, Humid air is forced to the muffler 160.

The hot and humid air with reduced noise in the muffler 160 is condensed while contacting and passing through the fins 151 of the heat exchange unit 150 vertically, and is converted into dry air. Collected (not shown).

The dry air exhausted from the heat exchange unit 150 is discharged to the room via the exhaust duct 181.

According to the ductless dryer according to the embodiments of the present invention described above, due to the muffler, the noise transmitted through the exhaust duct exposed to the room is reduced and at the same time the noise of the entire ductless dryer is reduced to create a quiet indoor environment do.

Claims (11)

main body; A drum rotatably installed on the main body; A heat exchanger for removing moisture contained in the air exhausted from the drum; A circulation duct for directing air exhausted from the drum to the heat exchange unit; An exhaust duct for guiding air exhausted from the heat exchanger to the outside; And Ductless dryer comprising a; muffler for reducing the noise transmitted through the exhaust duct. The ductless dryer of claim 1, wherein the muffler is disposed between the circulation duct and the heat exchange part. The ductless dryer of claim 2, wherein the muffler is connected to the heat exchanger in a straight line. The muffler according to any one of claims 1 to 3, wherein The first, second and third pipes are sequentially formed, the cross-sectional area of the second pipe is larger than the cross-sectional area of the remaining first, third pipe ductless dryer. 5. The ductless dryer according to claim 4, wherein the first pipe and the third pipe have the same cross-sectional area. The ductless dryer of claim 5, wherein the noise transmission loss L _T of the muffler is determined by the following equation.

Where, I: sound A ₁ in the second tube outlets: the first tube, the third tube cross-sectional area A ₂ of _the: second tube cross-section l of: Noise T in the second tube inlet of the second pipe length c: speed of sound f: frequency n = 1, 2, 3 ... f ₁ : target noise frequency (when n = 1) The method of claim 1, wherein the muffler, shell; And Includes; wraps the inner tube to form a noise space; Ductless dryer is a surface of the inner tube is a plurality of noise holes in communication with the noise space is open. 8. The ductless dryer of claim 7, wherein the exterior wraps all or part of the inner tube. The ductless dryer according to claim 8, wherein an angle (θ) surrounding part of the inner tube is 120 ° or less. 10. The method according to any one of claims 7 to 9, wherein the appearance is An outer wall enclosing the inner tube in a radial direction; And Ductless dryer comprising a; sidewalls to block the front and rear of the outer wall to form the noise space. The method of claim 7, wherein A target noise frequency to be reduced through the muffler is determined by the following equation ductless dryer.

Where p is the area percentage occupied by the noise hole in the area of the inner tube forming the floor of the noise space l: separation distance from inner tube to outer tube t: thickness of inner tube d: diameter of sound hole f _res : Target noise frequency

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