JPS596193Y2 - differential pressure damper - Google Patents

Description

[Detailed description of the invention] This invention operates under positive pressure to maintain the indoor pressure at a constant pressure, but when a pressure difference occurs between the inside and outside and the external pressure exceeds a predetermined limit. relates to a reciprocating differential pressure damper that operates in reverse to maintain internal and external pressure constant.

Clean rooms in factories that produce electronic parts, precision machinery parts, food, pharmaceuticals, etc., hospitals, etc. must maintain the indoor pressure at a constant positive pressure to prevent contaminated air from entering from outside.

Conventionally, most differential pressure dampers installed in such clean rooms are one-way type dampers that open only in the positive pressure direction and close when high external pressure is applied.

In the case of a one-way type, there is no problem if there is only one clean room, but if multiple clean rooms are installed adjacent to each other, problems arise.

This is because in such cases, ventilation is usually carried out through each room, and if the fan in one room were to stop due to a malfunction, the pressure in the adjacent room would become abnormally high, putting the room at risk. .

The present invention aims to provide a differential pressure damper that can be opened even when there is a reverse pressure, thereby avoiding the above-mentioned dangerous situation.

In this invention, a blade that opens and closes the ventilation port is pivotably supported in the outer casing, a packing having the required elasticity is fixed to the outer periphery of the blade, and a valve seat is mounted on the inner surface of the positive pressure side of the ventilation port. If the blade is not urged by its own weight, balance weight, etc. to rotate with the required pushing force in the direction of the valve seat, and if a back pressure exceeding a predetermined limit is applied, the above-mentioned packing The differential pressure damper is characterized in that the damper crosses over the valve seat and opens the ventilation port, and the illustrated embodiment will be described below.

In this embodiment, a type that penetrates the wall of an adjacent room is shown, but the same applies to a type that is relayed in the middle of a ventilation duct (not shown).

In the latter case, the outer casing consists of a frame with a flange joint that relays the ventilation duct.

In the figure, reference numeral 1 denotes an outer casing with flanges that is attached to sandwich a through hole 2 provided in a wall from the inside and outside.

The flange is joined to the wall surface via the packing 3.

This outer casing 1 has a rectangular opening, and a box-shaped bearing case 4 is fixed to both left and right sides of the opening, and approximately the upper half of the opening is closed by a U-shaped inner frame 5. The lower half part serves as a ventilation hole 6.

Reference numeral 7 denotes a blade for opening and closing the ventilation hole 6, and both ends of the shaft 8 are swingably supported by a needle-shaped shaft 9 hinged to the bearing case 4 and having an acute-angled tip support portion.

The blade 7 is divided into a portion facing the inner frame 5 and a portion facing the ventilation opening 6 with the shaft 8 as a boundary, and the former portion is provided with a housing portion 11 for a balance weight 10.

Balance weight 10 consists of 9 sticks cut into pieces,
By inserting an appropriate number of these into the housing section 11,
The couple of blades 7 is adjusted.

A packing 12 made of silicone rubber is fixed to the outer periphery of the latter portion by a presser plate 13, and a slight gap is provided between the outer periphery of the packing 12 and the inner surface of the ventilation hole 6.

14 is a packing for making the space between the shaft attachment part 15 of the blade 7 and the inner frame 5 airtight.

Reference numeral 16 denotes a valve seat protruding from the inner surface of the positive pressure side (right side in Figure 2) of the ventilation port 6. When the reverse pressure from the left side of the figure is slightly higher than the positive pressure, the packing 12 is brought into close contact with the valve seat 16. However, when the back pressure becomes higher than the positive pressure by more than a predetermined value, the packing 12 climbs over the valve seat 16 and the blades 7 open in the opposite direction, which prevents the high back pressure from becoming positive. It is designed to release to the pressure side.

17 is a cover of the bearing case 4, and 18 is a decorative cover.

When the differential pressure damper according to the present invention is used, when the clean room is operating normally, the air will flow normally and push the blades 7 open to the left in FIG. is maintained at a constant pressure.

The opening of the blade 7 in the forward direction is normally set to operate at a positive pressure of 1 to 4 mmAq.

Next, if the fan in a certain chamber (for example, the right chamber in Figure 2) stops due to a failure, the pressure in the adjacent chamber (left chamber) will gradually become higher than the pressure in the right chamber, so the blades 7 will The packing 12 rotates in the opposite direction to the valve seat 16 and closes the ventilation port 6. However, when the pressure in the left ventricle increases further and exceeds a predetermined limit, the packing 12 seats on the valve seat 16 and closes the ventilation port 6. Since the ventilation port 6 is opened in the opposite direction, the back pressure in the left ventricle is diverted toward the right ventricle, which prevents a drop in pressure in the right ventricle and also prevents pressure in the left ventricle from becoming abnormally high, which could be dangerous. This prevents this from happening and maintains the compartment under constant pressure.

This opening in the opposite direction is usually 8 mmAq or more and 20 mmA
It is set to operate below q.

Note that the blade 7 may be restored manually when the clean room returns to normal.

According to the present invention, when a clean room is in normal operating condition, each chamber is in communication and ventilation is performed, and each chamber is not only maintained at a constant pressurized state, but also when the pressure in a certain room is Even if the pressure becomes abnormally high due to a cause, if it exceeds a predetermined limit, the packing of the vane will climb over the valve seat and open the ventilation port in the opposite direction, so the abnormal pressure will be leaked to the adjacent room and the pressure in each chamber will be maintained constant. This will ensure the safety of the clean room.

Further, since the packing attached to the vane is made of silicone rubber and has a slight gap between it and the inner surface of the ventilation hole, the operation of the vane by counter pressure is smooth and reliable, and adjustment is easy.

Furthermore, due to the nature of silicone rubber, it does not adhere to valve seats, etc., and is highly durable.

[Brief explanation of the drawing]

Fig. 1 is a front view of the differential pressure damper according to the present invention with the decorative cover removed, and Figs. 2 and 3 are Fig. 1 I, respectively.
They are a vertical side view and an enlarged cross-sectional plan view taken along the -I line and the II-II line. 1: Outer case, 6: Ventilation port, 7: Blade, 12: Packing, 1
6: Valve seat.

Claims (1)

[Scope of utility model registration request] A blade that opens and closes the ventilation port is pivotally supported within the outer casing, a packing having the required elasticity is fixed to the outer periphery of the blade, and a valve seat is provided protruding from the inner surface of the positive pressure side of the ventilation port. At the same time, if the blade is not biased by its own weight, balance weight, etc. so as to rotate with the required pushing force in the direction of the valve seat, and if a back pressure exceeding a predetermined limit is applied, the packing will close to the valve seat. A differential pressure damper characterized in that the ventilation port is opened in the opposite direction by crossing the