JPH08226696A - Air supply and exhaust orifice for ventilation device - Google Patents

Abstract

PURPOSE: To facilitate a construction and to easily and effectively carry out counter measures when noise is generated after the construction by internally inserting an orifice plate having a section similar to the section of a ventilation duct and an orifice with an arbitrary aperture at its center, to the position of the ventilation duct near a ventilation device. CONSTITUTION: An orifice plate 4 is fitted coaxially to one of a plurality of proper positions near a ventilation device from the lower end opening of the ventilation duct 1. The orifice plate 4 has a diameter a little smaller than the inside diameter of the ventilation duct 1, a section similar to that of the ventilation duct 1 and an orifice hole 4-1 of arbitrary aperture at its center. The orifice plate 4 has an annular ptrotrusion 5-1 on the periphery of a rubber ring provided on its outer priphery which is fitted to an annular recessed groove 1-1 press- formed on the inner surface of the duct 1 so that the plate 4 is detachably fitted to the duct 1. A sound absorption material 6 is bonded to the upper surface of the orifice plate 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a supply / exhaust port orifice for reducing noise in a ventilation device of a ship or a land plant.

[0002]

2. Description of the Related Art For example, in a passenger ship, as shown in the longitudinal sectional view of FIG. 3, an exhaust duct is installed on the ceiling of a passenger room, and its exhaust port is provided on the ceiling, and indoor air is passed through an exhaust control section. As shown by the arrow, the air is exhausted to the outside through an exhaust duct and a fan. Conventionally, adjustment of the air volume to static pressure of this type of exhaust device is performed by arranging a control damper at an appropriate place, but if the place where the design and construction are not performed well can be adjusted, it will be described later. To do
Although it is possible to reduce scratching noise, it is costly and it is often difficult to take measures after construction work.

[0003]

That is, conventionally, in a system in which a single ventilator is used to supply or exhaust air in multiple compartments, the propagation noise generated from the ventilator is inevitable at the air supply / exhaust port near the ventilator. However, as shown by the white arrow, it propagates greatly to the cabin, and at that time, since the pressure loss of the duct is small, the throttle of the air supply / exhaust port becomes large. It's difficult. Further, the air-borne sound that propagates through the duct from the ventilator and is radiated from the air supply / exhaust port is often a serious problem as the air supply / exhaust port is closer to the ventilator. Also, regarding the rubbing noise generated at the air supply / exhaust port, since the pressure loss of the duct is small at the air intake / exhaust port near the ventilator, the differential pressure before and after the air supply / exhaust port increases, and the wind speed at the air supply / exhaust port increases. Since the air supply / exhaust ports are narrowed down to adjust the air volume, a high-speed air passes through a narrow gap to generate a rubbing noise.

The present invention has been proposed in view of the above circumstances, and has a simple structure and easy construction, and even after construction, when noise problems occur, measures can be taken easily and effectively. It is an object of the present invention to provide an economical and quiet air supply / exhaust port orifice for a ventilation device.

[0005]

In order to achieve such an object, the invention according to claim 1 has a ventilator attached to one end and the other end opening to a ceiling or wall of a room to be ventilated. In the ventilation duct that introduces the discharge air into the room, or discharges the room air to the outside by the same air blower, is inserted in a position near the air blower near the room side air supply / exhaust opening end of the air ventilation duct, An orifice plate having a diameter slightly smaller than the inner diameter of the ventilation duct, a cross section similar to the cross section of the ventilation duct, and an orifice having an arbitrary hole diameter at the center, and a sound absorbing material attached to the inner surface of the orifice plate. And means for fixing the outer peripheral portion of the orifice plate to the inner surface of the ventilation duct in a detachable manner.

According to a second aspect of the invention, in the first aspect, the differential pressure before and after the opening cross-sectional area of the air supply / exhaust metal fitting attached to the air supply / exhaust opening is substantially 250 P so that no friction noise is generated.
The cross-sectional area is set to be a or less.

[0007]

According to such a configuration, (1) the orifice plate functions as an acoustic reflection plate or a sound absorption plate for air-borne sound from the fan. (2) Regarding the prevention of scratching noise at the air supply / exhaust port, the orifice plate functions as a resistance plate to reduce the differential pressure across the air supply / exhaust port. (3) As a result, the propagating sound radiated from the air supply / exhaust port is reflected by the orifice plate due to the relationship between the cross-sectional area of the duct and the opening of the orifice. Decrease.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to an exhaust duct will be described with reference to the drawings. FIG. 1 is a longitudinal sectional view of the exhaust duct and an enlarged view of a mounting portion of the orifice plate to the duct. FIG. 2 is a plane view of the orifice plate of FIG. It is a figure and a side view.

In the above drawing, the same reference numerals as those in FIG. 3 indicate the same members as in FIG. 3, and the point that the present invention is largely different from the conventional structure of FIG. 3 is the position of the exhaust port of the duct near the ventilator. The point is that the orifice plate was fixed easily.

In the above drawing, reference numeral 2 denotes a supply / exhaust metal fitting installed in a portion of the lower end of the duct 1 opening to the ceiling 3, and the supply / exhaust metal fitting 2 expands downwardly into a conical casing portion 2-1.
And a conical air volume adjusting member 2-2 which is coaxially supported by a center bolt 2-3 and which expands downward.

Reference numeral 4 denotes an orifice plate (hereinafter referred to as an orifice) coaxially fitted to one of a plurality of appropriate positions near the ventilator from the lower open end of the duct 1. The orifice 4 is shown in FIG. As shown in the enlarged view, it can be detached by fitting the annular projection 5-1 on the outer periphery of the rubber ring around the outer periphery of the rubber ring into the annular groove 1-1 formed by pressing on the inner surface of the duct 1. Is fitted to. Reference numeral 6 is a sound absorbing material attached to the upper surface of the orifice 5.

In such a structure, the air volume adjusting member 2
-2 is squeezed to a certain amount, where the pressure difference between the front and rear becomes large, the orifice hole is designed so that the pressure difference is 250 Pa or less or the duct wind speed is 5 m / s or less. . The duct 1 has a circular cross section of 100φ to 150φ, but may have a rectangular cross section.

The orifice or baffle plate of the present invention is mounted on the ventilator side of the air supply / exhaust port to reflect the sound propagated from the ventilator and to prevent scraping noise at the air supply / exhaust port. Further, since this orifice can be easily inserted from the air supply / exhaust port, it has a feature that even if a noise problem occurs, countermeasures can be easily taken.

[0014]

According to such a structure, the following effects can be obtained. (1) It is possible to prevent the generation of noise and scraping noise at the air supply and exhaust ports of the ventilation device. This is because it is not necessary to tighten and narrow the air volume adjusting unit by inserting the Ophiris, so that no scraping noise is generated. (2) Even after the construction work has already been completed, it is possible to carry out the countermeasure work just by inserting the orifice, and the countermeasure cost can be reduced. This is because the rubber ring of the orifice can be easily inserted into and removed from the annular groove on the inner surface of the duct. (3) It is possible to easily take noise prevention measures at difficult noise generating points at the design stage.

In short, according to the first aspect of the invention, the ventilator is attached to one end and the other end is opened to the ceiling or wall of the chamber to be ventilated, and the discharge air of the ventilator is introduced into the chamber or the indoor air. In the ventilation duct that discharges the air to the outside by the same ventilation device, it is inserted in the vicinity of the room-side air supply / exhaust opening end of the ventilation duct and near the ventilation device, and has a diameter slightly smaller than the inner diameter of the ventilation duct. An orifice plate having a cross-section similar to that of the ventilation duct and having an orifice with an arbitrary hole diameter in the center, a sound absorbing material attached to the inner surface of the orifice plate, and the outer peripheral portion of the orifice plate are provided with the ventilation duct. By having a means for removably fixing to the inner surface of the, the structure is simple and the construction is easy, and
Even after the construction, when the noise problem occurs, an economical and quiet ventilation inlet / outlet orifice of the ventilation device that enables easy and effective countermeasures is obtained. Is.

According to a second aspect of the present invention, in the first aspect, the differential pressure before and after the opening cross-sectional area of the air supply / exhaust metal fitting attached to the air supply / exhaust opening is substantially 250 P so that no friction noise is generated.
Since the cross-sectional area is set to a or less, the structure is simple and the construction is easy, and even after the construction, when a noise problem occurs, it is possible to easily and effectively take countermeasures, which is economical and quiet. The present invention is extremely useful in the industry because it can provide the inlet and outlet orifices of a ventilation device.

[Brief description of drawings]

1 shows an embodiment in which the present invention is applied to an exhaust duct for indoor air, FIG. 1 (A) is an overall longitudinal sectional view thereof, and FIG. 1 (B) is an enlarged view showing an orifice mounting portion B thereof. .

FIG. 2 is a plan view and a side view showing the orifice plate of FIG.

FIG. 3 is a vertical sectional view showing an exhaust port of a conventional duct.

[Explanation of symbols]

 1 Duct 1-1 Annular groove 2 Air supply / exhaust hardware 2-1 Casing part 2-2 Air volume adjusting member 2-3 Center bolt 3 Indoor ceiling 4 Orifice plate (orifice) 4-1 Orifice hole 4-2 Rising part 5 Rubber ring 5-1 Annular ridge 6 Sound absorbing material

Claims (2)

[Claims] 1. A ventilator is attached to one end and the other end is opened to a ceiling or wall of a chamber to be ventilated, and the air discharged from the ventilator is introduced into the chamber or the indoor air is discharged to the outside by the ventilator. In the ventilation duct, it is inserted near the room-side air supply / exhaust opening end of the ventilation duct and close to the fan, and has a diameter slightly smaller than the inner diameter of the ventilation duct and similar to the cross section of the ventilation duct. An orifice plate having a cross section and an orifice with an arbitrary hole diameter in the center, a sound absorbing material attached to the inner surface of the orifice plate, and the outer peripheral portion of the orifice plate is detachably fixed to the inner surface of the ventilation duct. An air supply / exhaust port orifice of a ventilation device, comprising: 2. The open / close sectional area of the supply / exhaust metal fitting attached to the supply / exhaust opening according to claim 1, wherein the differential pressure before and after the supply / exhaust opening is approximately 250 Pa or less at which no rubbing noise is generated. Air supply / exhaust orifice of the ventilation device.