JPH11316089A - Noise reducer for air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To absorb reflected sound by standing a tubular frame having diameter substantially equal to the minimum width of an air conditioner or a square frame having length of one side substantially equal to the minimum width around the upper air outlet of housing thereby preventing upper diffusion of wind breaking sound and moderating current velocity of blow-up air flow. SOLUTION: A wide opening muffler hood 10 standing around an air outlet 4 opening to the upper surface 3 of a unit comprises a secured square frame 11 having width equal to the minimum width of housing. An acoustic material, e.g. a sponge, or a punching plate may be pasted to the inner surface 12 of the frame. A muffler panel 7 comprising a PVC plate may be arranged in U- shape on the maximum noise generating plane, i.e., on the suction side 2. The interval W3 depends on the body size and it is normal 0.8 m or above. When a plurality of air outlets 4 and fans 5 are provided above the housing, inside of the frame 11 is sectioned by a partition wall 13 to constitute wide opening muffler hoods for individual fans.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a muffler for reducing the blowing noise of a fan of a heat exchanger and other air conditioners, such as an air conditioner or a cooling tower, which is mainly installed on the roof of a building.

[0002]

2. Description of the Related Art A heat exchanger with a fan and other various air conditioners installed on the roof of a building include a circulating pump and other operating noises, sprinkling noises and air suction noises from a lower portion and a side surface, and a forced air cooling fan from an upper portion. It is a source of various noises such as noise. As a measure against noise from the lower part and the side of the main body, a group of air conditioning machines is surrounded by a sound insulating wall. Also, as for the upper noise, for example, in air conditioners, as shown in FIGS. 1 and 2, a cylindrical hood with the same diameter as the air outlet is erected for each unit to reduce the noise generated from the fan. I have. But,
In this means, not only the wind noise is pushed upward as it is, but also the high-speed airflow in the hood, the airflow noise and the reflected sound in the cylinder are generated, so that the expected silencing effect cannot be obtained. For this reason, it was originally attempted to reduce the upper noise by increasing the height k of the sound insulation wall for noise reduction of machine operation noise etc. (referred to as main body noise) to reduce the upper noise, but the high sound insulation wall caused hot air to stay or Acts as a guide wall to the device, causing a so-called short-circuit phenomenon to make the device inoperable.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the conventional dilemma between a sound deadening hood and a sound insulating wall. To provide a noise reduction device by combining a new noise reduction hood capable of absorbing reflected sound and a main body noise reduction unit.

[0004]

SUMMARY OF THE INVENTION The present invention surrounds the air outlet of an air conditioner having a fan for cooling and blowing a heat exchange mechanism in an air outlet at an upper portion of a housing, and is substantially equal to a minimum width of the air conditioner. A wide-mouth silence hood having a cylindrical or rectangular frame having a diameter or a square or rectangular frame having a side length substantially equal to the minimum width, and at least one of an air-conditioning machine provided with the wide-mouth silence hood has a maximum. The noise generating surface is surrounded or connected by a main body noise reducing means such as a sound deadening panel at an appropriate interval. In the case where a plurality of outlets are provided on one housing, the ventilation portion is formed by a frame partitioned from the inside of the frame corresponding to each outlet. It is more effective to provide a sound absorbing rib in a horizontal direction on the inner wall of the ventilation section. The frame body or the partition wall is made of a metal or a synthetic resin subjected to a sound absorbing process, and the sound absorbing rib is a metal plate provided with a sound absorbing material such as a synthetic resin film on the surface or a synthetic resin plate provided with a sound absorbing process on the surface. In the present invention, the main body noise reduction means refers to a surrounding wall formed of a sound absorbing member such as a commercially available sound deadening panel in which a synthetic resin plate is combined. The sound deadening panel, etc. is usually erected in an L-shape or U-shape in consideration of mechanical strength, and its height is almost the same as the height of the unit main body, or even if it is higher, it is lower than the upper opening surface of the wide mouth sound deadening hood .

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, reference numeral 1 denotes an air conditioner unit, 2 denotes a maximum noise generating surface having an air intake port, etc., 4 denotes an outlet opening on an upper surface 3 of the unit, and 5 denotes an upward axial flow fan. It is. 6 is about 1 m or more S
It is an existing sound insulation wall that is fixedly installed at a distance from the roof, and the height k is usually higher than the upper surface of the unit. Figure 1,
In FIG. 2, f is a conventional sound deadening hood (about 1 m in height). When this hood was provided, the height of the wall had to be increased as in g, so that a short circuit was likely to occur. Figure
3 and the following figures, reference numeral 10 denotes a wide-mouth noise-reduction hood of the present invention, in which a rectangular frame 11 having the same width as the minimum width of the housing is fixed. The height of the frame body 11, that is, the height H of the ventilation portion 10A is about 1 m. A sound absorbing material such as sponge or a perforated plate may be attached to the inner surface 12 of the frame. 3 and 4, spacing W ₃ a example of a main noise reduction unit and continuously provided a muffling panel 7 made of a plate material made of vinyl chloride to the suction side 2 of maximum noise generation plane in a U-shaped main body It is usually 0.8m or more, though it depends on the size.

[0006] When a plurality of air outlets 4 and a plurality of fans 5 are provided in the upper part of the housing, the inside of the frame 11 is partitioned by a partition wall as shown in FIGS.
Each fan is divided by 13 to form a separate wide-mouth silencing hood. 7 and 8, reference numeral 15 denotes a sound absorbing rib, which is provided on the inner surface 12 of the frame or the inner surface of the partition wall of the sound deadening hood,
It is composed of a flat plate or a downward swash plate 16. For example, a soft synthetic resin film is preferably formed on the outer surface of the sound absorbing rib. In each of the above devices, the wind noise of the fan 5 and the rising air flow are within the hood,
That is, the hood opening surface 1
The sound quality at 4 is different from the sound quality of the fan part, and it is low level and low range. Therefore, even if the main body noise such as mechanical sound is the same, the overall noise level can be reduced in combination with the sound insulation effect of the sound deadening panel.

[0007]

[Embodiment] (Embodiment) The air conditioner body 1 shown in FIGS.
Body height h₁= 2.25m, footnote height h_Two= 0.45m, body width W _Two= 3m, book
Body minimum width W₁= 1.8m, outlet diameter about 1.2m, fan motor
(Not shown) is three-phase 200V, 2.2KW. Main body left and right suction
Mouth 2 to W_Three= 1m away and a 3mm thick vinyl chloride plate
It was assembled in a shape as a muffling panel 7 and connected to the main body. Wide mouth
3mm thick, W as sound hood 10₁= 1.8m, H = 1m vinyl chloride tree
A square frame was constructed using a fat plate. (Comparison device) Made of vinyl chloride as shown in Fig. 1
A cylindrical body f (diameter: about 1.2 m, H = 1 m) was fixed. (Measurement results) In each of the above devices, distance 5 from air inlet 2
m, a sound level meter M (microphone) at 1.5 m
When the sound deadening hood is not attached to the body, the comparison device and the embodiment
Table 1 shows the results of measuring the noise levels of the equipment in a windless state.
It seemed.

[0008]

【table 1】

[0009] In the above measurement, in order to confirm the effect of the wide mouth sound deadening hood, no sound absorbing material or the like is used on the inner surface of the wide mouth sound deadening hood 10 in the embodiment apparatus. Therefore, it is clear that a device provided with a known sound absorbing treatment or a sound absorbing rib can obtain a sound absorbing effect more than the above measurement result.

[0010]

The wide mouth sound deadening hood of the present invention is much larger than the diameter of the air outlet, so that the flow velocity of the ventilation portion is reduced, and the sound absorbing rib can be attached to the inner surface of the hood to enhance the sound deadening effect. Furthermore, the configuration of the device is simple and economical, and
Since there is no need to increase the height and the width of the machine is not increased, there is an advantage that it can be installed anywhere as long as the installation area is the same as when a conventional sound insulation wall or the like is provided.

[Brief description of the drawings]

FIG. 1 is an elevation view of an air conditioner unit provided with a conventional cylindrical hood.

FIG. 2 is a plan view of FIG. 1;

FIG. 3 is an elevation view of the muffler of the present invention.

FIG. 4 is a plan view of FIG. 3;

FIG. 5 is a plan view of a four-partition section type sound deadening hood.

FIG. 6 is a plan view of a three-segment partition type silencing hood.

FIG. 7 is a plan view showing an arrangement example of sound absorbing ribs.

FIG. 8 is an enlarged cross-sectional view taken along line AA of FIG. 7;

[Explanation of symbols]

 1 Main unit 2 Inlet 4 Outlet 5 Axial fan 7 Sound deadening panel 10 Wide-mouth sound deadening hood 10A Ventilation section 11 Frame 12 Inner surface 13 Partition wall 14 Hood opening surface 15 Sound absorbing rib 16 Downward swash plate

Claims (4)

[Claims] 1. A wide-mouth silencing hood comprising a cylinder having a diameter substantially equal to a minimum width of an air conditioner housing or a rectangular frame having at least one side length substantially equal to the minimum width is provided at an upper part of the housing of the air conditioner. Noise reduction device that stands upright around the air outlet. 2. A cylinder having at least one maximum noise generating surface side of an air conditioner having a cooling fan in an air outlet at an upper portion of a housing and surrounded by body noise reduction means and having a diameter substantially equal to the minimum width of the housing. Alternatively, a noise reduction device in which a wide-mouth silencing hood formed of a rectangular frame is erected around the outlet. 3. The device according to claim 2, wherein individual rectangular wide-mouth sound deadening hoods are provided for a plurality of outlets provided in an upper portion of the housing, and an outer width dimension of at least one side of each wide-mouth sound deadening hood. Is formed substantially equal to the minimum width of the housing. 4. The apparatus according to claim 1, wherein a sound absorbing rib is provided on an inner surface of the sound deadening hood.