JPS5815815Y2 - Gas water heater safety device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a safety device that can immediately restore normal pressure when the pressure inside a gas water heater becomes overpressure or negative pressure.

Conventionally, gas water heaters have been known that use water pressure-responsive gas valves made of diaphragms that open and close gas valves to gas burners in response to changes in water pressure in water supply channels to heat exchangers. In a gas water heater having such a structure, the diaphragm is actuated by a change in water pressure in the water supply flow path to the heat exchanger caused by opening and closing a hot water tap disposed downstream of the heat exchanger. In the so-called stop-start type, the heating fluid flow path from the heat exchanger to the tap tap is long, or the balance between the water pressure and the operation of the diaphragm, spring, etc. that are the components of the water pressure automatic gas valve. For this reason, the gas valve is not immediately closed when the hot water tap is closed, and the heat exchanger is temporarily heated to an abnormally high pressure.

The abnormally high pressure may be caused by the amount of residual heat in the heat exchanger.

Conventionally, water heaters have been equipped with a safety valve device for releasing high-pressure fluid as a means for releasing such abnormally high pressure.

Normally, when a gas water heater is finished being used, some water remains in the water flow path, but when it is extremely cold, this residual water freezes in the water flow path and damages the equipment, so it is no longer used. It is equipped with a drain plug for draining the remaining water.

However, in reality, the residual water cannot be drained reliably unless, for example, a hot water tap is opened at the same time as the drain valve is opened.

Moreover, in the first-stop type, the hot water tap and the drain tap may be located very far apart, and in that case, the operation to open both becomes extremely time-consuming.

Furthermore, when a rubber hose, etc. was inserted into the hot water tap, and the outlet of the hose was submerged in hot water while supplying hot water to the bathtub, the water supply cut off, and the water supply was interrupted because the water was left in that state. There is a possibility that the pressure inside the bathtub will become negative and the hot water in the bathtub will flow back into the water supply.

Therefore, it is mandatory to install a check valve between the gas water heater and the water supply.

The present invention provides a safety device that can solve all of the above-mentioned problems with conventional water heaters. By using a flexible diaphragm valve made of rubber or plastic that can immediately respond to this situation and also exhibit a perfect sealing effect, and a rigid plate-shaped valve body that cooperates with the diaphragm valve, The feature is that it has both an overpressure release safety valve function and an automatic intake valve function.

The present invention will be explained below using examples shown in the drawings.

The gas water heater shown in FIG.
A water circuit consisting of a water drain plug 4 provided in parallel with the automatic water pressure gas valve, and a hot water tapping tap 6 provided at the tip of the heated fluid flow path 5 connected to the downstream side of the heat exchanger 2; , a gas valve 9 operated by a diaphragm (not shown) of the hydraulic automatic gas valve 1 provided in the middle of a gas passage 8 connecting a gas supply pipe (not shown) and the main burner 7; and a pilot burner 1 provided in parallel/with the main burner.
0 and a gas circuit consisting of a pilot gas valve 11.

According to the present invention, the gas water heater is configured such that the heating fluid flow path 5
It is equipped with a safety device consisting of an open flow path 12 that is branched from the air flow path and communicates with the atmosphere, and a safety valve mechanism 13 of a specific structure that is provided within the open flow path.

The detailed structure of the safety device is shown in FIGS. 2 to 4.

In the embodiment of FIGS. 2 to 4, the open channel 12
is connected by a T-shaped pipe 15 to the heating fluid passages 5a and 5b, which connect one end to the secondary side of the heat exchanger and the hot water tap run (see Fig. 1), and the other end to a large-diameter circular pipe. Box 16
It is formed in the shape of.

A circular lid 17 is removably fitted to the open end 16a of the circular box 16, and the lid has a circular through hole 17a in the center.
and a plurality of lips 17b protruding inward of the box provided at appropriate intervals along the through hole.

A pair of valve bodies consisting of a disk-shaped hard valve 18 and a flexible diaphragm valve 19 made of rubber are provided inside the circular box 16 portion.

The hard valve 18 has a fitting protrusion 18a at the center, a fitting groove 18b at the outer edge, and an intermediate portion i'i1 between the center and the outer edge:
It has a guide hole 18c.

The diaphragm valve 19 has a center through hole 19a, an outer edge button 19b, and a center protrusion 19c, which are respectively provided continuously to the outer edge button of the valve and the through hole 19a, and the height of the center protrusion 19c is equal to the outer edge protrusion. It is formed smaller than that of 19b.

The hard valve 18 and the diaphragm valve 19 have a fitting protrusion 18a of the hard valve connected to a central through hole 19a of the diaphragm valve.
The hard valve 18 is fitted into the outer edge projection of the diaphragm valve 19 due to the elastic force of the spring 20 installed between the fitting groove 18b of the hard valve and the circular lid body 17. 19b is pressed against the bottom wall of the circular box 16 portion.

The spring 20 presses the rigid valve and the diaphragm valve against the bottom wall of the circular box portion against the pressure when the pressure in the heated fluid channels 5a, 5b is within a predetermined pressure range. When the pressure exceeds a predetermined pressure, the diaphragm valve contracts due to the pressure, and has an elastic force that causes the diaphragm valve to move away from the bottom wall surface of the circular box portion.

A central portion of the diaphragm valve 19 having a central through hole 19a and a central protrusion 19c continuous with the through hole is a central portion of the diaphragm valve 19.
Rigid valve 1 due to its own rubber elasticity and the assistance of spring 21
It is in close contact with the fitting protrusion 18a of No.8.

The spring 21 is contracted by atmospheric pressure when the pressure in the heated fluid passages 5a and 5b becomes negative than atmospheric pressure, thereby causing the fitting protrusion 18a of the hard valve 18 to pass through the center hole of the diaphragm valve 19. It has a resilient force that moves the parts 19a apart.

The safety device of the present invention having the above-mentioned structure is provided with a second
As shown in the figure, the through hole 18C of the hard valve 18 and the open flow path 1 are tightly closed by the diaphragm valve 19 having rubber elasticity, so that the hot water or steam flows through the heated fluid flow paths 5a and 5b. The hot water is then discharged from the tap.

When you finish using the gas water heater and close the hot water tap,
As mentioned earlier, if the pressure in the heated fluid flow paths 5a and Sb rises due to a slight delay in the operation of the hydraulic automatic gas valve and becomes even slightly higher than the predetermined pressure, the diaphragm valve 19 has a large pressure-receiving area. Throttle valve 19 and hard valve 1 as shown
8 is pushed up, the heating fluid channels 5a and 5b communicate with the atmosphere through the open channel 12, and the pressure in the warming fluid channel decreases to 1, which becomes equal to atmospheric pressure.

As soon as normal pressure is reached in the flow path, both valves 18 and 19 close the open flow path 12 in response.

At the same time as the use of the gas water heater is finished, the drain valve 4 shown in FIG. Since water tries to escape from the drain plug 4 due to its own weight, the pressure on the open channel side of the diaphragm valve 19 becomes negative than the atmospheric pressure, as shown in FIG.
Immediately in response to this, the central through-hole 19a portion of the throttle valve curves toward the open flow path.

In this way, atmospheric pressure is introduced into the heated fluid flow path 5a through the central through hole 19a of the diaphragm valve 19, the through hole 18c of the hard valve 18, and the open flow path 12, so that residual water is rapidly drained from the drain plug 4. Ru.

By introducing atmospheric pressure into the heating fluid flow path through the safety device of the present invention, backflow from the hot water tap to the water supply system during the above-mentioned water outage is also prevented.

As described above, the safety device of the present invention uses a flexible diaphragm valve made of rubber or plastic to open the air flow hole of the hard plate-shaped valve body paired with the throttle valve and the water heater's overpressure during normal operation. While the flow path opening can be completely sealed, when the inside of the water heater pipe becomes overpressure or negative pressure, the diaphragm valve, which has a large pressure receiving area and is highly flexible, is instantly released. Normal pressure can be restored.

In addition, the central through hole formed in the center of the diaphragm valve always fits accurately and tightly with the fitting protrusion formed in the center of the hard plate-shaped valve body corresponding to the through hole, and the gap between the two valve bodies is maintained. It has many practical advantages such as being able to exhibit a perfect sealing effect.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing a typical structure of a gas water heater equipped with a safety device of the present invention, and FIGS. 2 to 4 are sectional views showing the structure of a safety device according to an embodiment of the present invention. . 1... Water pressure automatic gas valve, 2... Heat exchanger, 3... Water supply channel, 4... Water drain plug, 5... ... Warming fluid flow path, 6 ... Hot water extraction tap, 7 ... Main burner, 8 ... Gas flow path, 9 ... Gas valve, 10. ...Pilot burner, 11...Pilot gas valve, 12...
...Open flow path, 13...Safety valve mechanism, 15
...T-shaped tube, 16 ... Circular box, 17
......Circular lid body, 18......Rigid valve, 19
...Diaphragm, 20,21...Spring.

Claims (1)

[Scope of utility model registration request] A safety device provided in an open flow path that branches from a heated fluid flow path downstream of a heat exchanger and communicates with the atmosphere, and the safety device includes a ventilation hole in the center that communicates with the atmosphere; A circular lid body having a gap that can still communicate with the atmosphere when the through hole is closed by the hard plate-shaped valve body and the flexible diaphragm valve body described later is fitted at one end, and the open hole is fitted at the opposite end. A valve case having a communication hole that communicates with a flow path, a hard plate-like valve body housed in the valve case, and a hard plate-like valve body that is in close contact with one surface of the hard plate-like valve body so as to be able to freely separate from the body, and the hard plate-like valve body. and a flexible diaphragm valve body pressed so as to open and close the communication hole of the valve case, and the hard plate-shaped valve body has a fitting protrusion in its center and a fitting protrusion in the center thereof. A required number of atmospheric air flow holes are provided between the protrusion and the outer edge, and the flexible diaphragm is configured to close the rigid plate-shaped valve body when the inside of the heated fluid flow path is within a predetermined pressure range. A gas valve characterized by having a central through hole in its center that aligns with the fitting protrusion of the valve body, and an annular protrusion on its outer edge that is in constant contact with a wall surface having a communication hole of the valve case. Water heater safety device.