JPH0136049Y2 - - Google Patents

Description

[Detailed description of the invention] This invention uses a hydraulic automatic gas valve that is linked to a hydraulic response device in a stop-start instantaneous gas water heater, etc. as a double valve to supply water downstream from the primary diaphragm chamber of the diaphragm chamber of the hydraulic response device. The present invention relates to a device for preventing dry heating of a gas water heater, which prevents dry heating caused by clogging of a hot water supply system or the like.

In source-stop type instantaneous gas water heaters, etc., the cause is clogging of the water supply or hot water supply line downstream from the primary diaphragm chamber of the diaphragm chamber of the hydraulic response device, especially if the flexible faucet is bent or bent, or the heat absorption pipe is clogged. If the water supply to the heat exchanger is reduced or stopped, the hot water pipes may overheat or run dry. In other words, the hydraulic response device that has been commonly used in the past divides the diaphragm chamber into a primary diaphragm chamber and a secondary diaphragm chamber, and the valve stem of the water volume adjustment valve provided on the primary diaphragm chamber is brought into contact with the diaphragm. The structure is such that the opening degree of the hydraulic automatic gas valve is controlled via the valve shaft provided on the secondary diaphragm chamber side by the fluctuation of the water supply pressure acting on the primary diaphragm chamber side.
The hydraulic automatic gas valve is a single valve (single-sided valve) with one seal, and is merely used to increase or decrease the amount of gas supplied to the main burner approximately in proportion to the amount of inflow. Therefore, if the pressure in the primary diaphragm chamber increases due to blockages in the water supply or hot water supply system, the opening degree of the water pressure automatic gas valve will further increase.
The opening degree of the water flow control valve is further reduced, the flow rate of water is reduced, and the overheating tendency is promoted, and the main burner continues to perform full-input combustion, resulting in a dry firing state.

This invention was made with the aim of eliminating such drawbacks, and consists of making the hydraulic automatic gas valve interlocked with the hydraulic response device into a double valve, one of which is used as a gas shutoff valve in the event of overheating or dry firing. This gas water boiler improves safety by immediately stopping gas supply to the main burner in the event of a blockage in the water supply or hot water supply line downstream of the primary diaphragm chamber of the hydraulic response device, thereby preventing dry heating. The present invention provides a device for preventing empty heating of a vessel.

One embodiment will be described below in detail based on the drawings. In the drawings, A is a hydraulic response device, which divides a diaphragm chamber 1 into a primary diaphragm chamber 1a and a secondary diaphragm chamber 1b by means of a diaphragm 2. The upstream side 3a and downstream side 3b of the water supply channel 3 are communicated through the valve chamber 4 formed on the upstream side 3a near the primary diaphragm chamber 1a. The water flow regulating valve 5 is brought into contact with the diaphragm 2 via the shaft 6 and is connected to the water flow rate regulating valve 5 by the spring 7.
In addition, a hydraulic automatic gas valve V installed in the gas passage 8 is connected to the secondary diaphragm chamber 1b side via the diaphragm 2 and the valve shaft 9 to act on the primary diaphragm chamber 1a side. The opening degree of the water pressure automatic gas valve V is automatically controlled based on fluctuations in water supply pressure. The above-mentioned water pressure automatic gas valve V is integrally formed with a gas cutoff valve V ₁ having a seal portion at the front and rear ends (in the opposite direction), and a gas amount adjustment valve V ₂ , and a valve provided in the gas passage 8 . The valve seats 11 and 12 facing each other in the chamber 10 are interposed so that they can freely move forward and backward, and one gas cutoff valve _V1 is connected to the valve seat 11, and the other gas amount adjustment valve _V2 is connected to the valve seat 11. The valves V ₁ and V ₂ move in concert with the movement of the diaphragm 2 due to fluctuations in the water supply pressure acting on the primary diaphragm chamber 1a side of the diaphragm chamber 1. The valve seats 11 and 12 can be brought into and out of contact with each other alternately. In the figure, reference numeral 13 indicates a return spring for the hydraulic automatic gas valve V, and the spring 13 urges one gas cutoff valve V ₁ in the opening direction and the other gas volume adjustment valve V ₂ in the closing direction. ing. Reference numeral 14 denotes a temperature control valve, which is provided on the downstream side 3b of the water supply channel 3. A water supply pipe 15 connects the downstream side 3b of the water supply channel 3 and the heat exchanger 16. 17 is an inner shell, and a heat exchanger 16 is provided on the upper part of the inner shell. A hot water supply pipe 18 is led out from the heat exchanger 16. A flexible faucet 19 is attached to the tip of the hot water pipe 18. A main burner 20 is a heating source for the heat exchanger 16. 21 is a gas supply pipe connected to the gas passage 8. 22 is a gas nozzle.

In the above configuration, when the water pressure automatic gas valve V is not in use in a normal state where there is no clogging of the water supply or hot water supply line, the hydraulic automatic gas valve V is pushed to the right in the figure by the elastic force of the return spring 13 of the water pressure automatic gas valve V. Gas amount adjustment valve V ₂
The seal portion of the valve is pressed against the valve seat 12 to block the gas passage 8 to the main burner 20, and the diaphragm 2 is also pushed to the right via the valve shaft 9 to force the water flow regulating valve 5 against the spring 7. It is kept fully open. Therefore, when the water stop valve (not shown) is opened to allow water to flow to the downstream side 3b of the water supply channel 3 during use, water enters the primary diaphragm chamber 1a from the upstream side 3a of the water supply channel 3 via the water volume adjustment valve 5. , the water pressure causes diaphragm 2
is pushed and deformed to the left in the figure, and the hydraulic automatic gas valve V is moved to the left via the valve shaft 9, and the gas amount adjusting valve V ₂ is moved to the left.
is separated from the valve seat 12 to open the gas passage 8. The opening degree at this time is such that the hydraulic automatic gas valve V is located approximately midway between the valve seats 11 and 12, and the gas cutoff valve _V1 on the opposite side is also spaced apart from its valve seat 11 to maintain a constant opening degree. There is. (The position indicated by the chain line in the drawing.) Thereafter, the opening degree of the gas amount regulating valve _V2 is automatically controlled in accordance with fluctuations in the water supply pressure. On the other hand, water supply channel 3
The amount of water flowing from the upstream side 3a to the downstream side 3b, that is, the amount of water flowing into the primary diaphragm chamber 1a, is controlled to be constant by the water amount regulating valve 5.

Next, during use, if the water supply or hot water supply line downstream of the primary diaphragm chamber 1a, that is, the water supply pipe 15 is clogged, the heat absorption pipe of the heat exchanger 16 is clogged, or the flexible faucet 19 is bent or bent. In this case, the water supply to the heat exchanger 16 is cut off, so the pressure within the primary diaphragm chamber 1a rises rapidly, and this pressure further pushes the diaphragm 2 to the left in the figure. Therefore, the hydraulic automatic gas valve V, which is interlocked via the diaphragm 2 and the valve shaft 9, is simultaneously pushed to the left in the figure, and the seal portion of the gas cutoff valve _V1 is pressed against its valve seat 11, thereby closing the gas passage. 8 to stop the gas supply to the main burner 20.
(Position of the solid line in the drawing.) As explained above, this idea uses a hydraulic automatic gas valve of a hydraulic response device as a double valve with seals at the front and rear ends (in the opposite direction), and water is supplied using one of the gas cutoff valves. The structure is designed to shut off the gas passage to the main burner in the event of a blockage in the hot water supply system, which prevents dry heating caused by a blockage in the water supply or hot water supply system, which was a bottleneck in the past. It is extremely safe and effective in actual use.

[Brief explanation of drawings]

The drawing is a sectional view showing an embodiment of this invention. A...Hydraulic response device, V...Hydraulic automatic gas valve,
V ₁ ... Gas cutoff valve, V ₂ ... Gas amount adjustment valve, 1
...Diaphragm chamber, 2...Diaphragm, 5...
...Water flow adjustment valve, 11...Valve seat of gas cutoff valve V ₁ ,
12...Valve seat of gas amount adjustment valve _V2 , 20...Main burner.

Claims (1)

[Scope of utility model registration request] The water-pressure automatic gas valve opens and closes in conjunction with a diaphragm that responds to water pressure to supply and shut off gas to the main burner. Seals are provided at the front and rear ends of the automatic gas valve to create a double valve, with each valve separated between opposing valve seats. The seals at the front and rear ends of the multiple valves are separated from each valve seat through the diaphragm under normal water pressure to automatically open the gas valve and prevent blockage of the water supply pipe. A dry heating prevention device for a stop-start type gas water heater, characterized in that a water pressure automatic gas valve is closed by bringing a front end seal part into contact with a valve seat by advancing a diaphragm under abnormally high pressure.