JPS589701Y2 - stationary water heater - Google Patents

Description

[Detailed description of the invention] This invention relates to a stationary gas water heater installed in a kitchen or the like.

In general, water heaters are of the so-called mixing type, which mix hot water and cold water to dispense hot water in order to increase the amount of hot water dispensed and expand the temperature control range.

Furthermore, in order to deal with the after-boiling phenomenon, water heaters are equipped with a pressure safety device that opens a valve to release excess pressure when the pressure inside the casing increases.

However, when this kind of mixing type water heater is installed as a stationary type, the water supply pipe is connected to the heat exchanger through a differential pressure type water pressure response device equipped with a diaphragm placed above the heat exchanger. In the case where the piping is installed above the heat exchanger and a pressure safety valve is provided in the hot water supply pipe, and a bypass pipe is branched from the water supply pipe downstream of the hydraulic response device and connected to the hot water supply pipe, the hot water expanded during post-boiling is passed through the bypass pipe. Flows backward into the hydraulic response device, causing problems such as malfunction of hydraulic gas valves, premature aging of diaphragms, and non-operation of pressure relief valves.

The present invention solves these problems with a simple structure, and will be specifically explained below based on an embodiment shown in the drawings.

1 is a stationary water heater main body, and the main body 1 is divided by a partition plate 2 into a balance box 3 and a piping room 4.

A heat exchanger 5, a heating burner 6, a pilot burner 7, a thermocouple 8, and a spark plug 9 are disposed within the balance box 3.

10 is a balanced intake and exhaust device, 11 is a pressure safety valve, 12
is a nozzle that sprays steam onto the thermocouple 8 when the safety valve 11 is activated.

13 is a drain plug provided at the lowest position of the water supply pipe 14.

Also, inside the piping chamber 4 is a safety valve 1 which is opened and closed by an operating shaft 15.
6. Pilot valve 17, main valve 18 and the above main valve 1
A gas valve unit 22 is installed in the downstream gas path of the heat exchanger 5, and includes a hydraulic gas valve 19 that is opened and closed by a hydraulic response device, which will be described later, and a capacity valve 21 that is opened and closed by a shaft 20. Water flow rate to a water pressure response device 23 equipped with a differential pressure diaphragm interposed in a water supply pipe 14 connected from above, a wood conditioning device 24 of the device 23, and a heat exchanger 5 provided downstream of the wood conditioning device 24. and a temperature control valve 26 that regulates the amount of water flowing into the bypass pipe 25 branched from the downstream side of the hydraulic response device 23.

A hot water supply pipe 28 connected to the heat exchanger 5 is also led into the piping chamber 4, and the hot water supply pipe 28 and the bypass pipe 25 are connected to a mixing fitting 29.

30 is a hot water tap. FIG. 2 shows a sectional view of the main part of the present invention.

That is, the cylindrical protrusion 3 from the chamber wall of the valve chamber housing the temperature control valve 26
A hollow cylindrical body 33 having a flow path 32 is inserted into the cylindrical protrusion 31, and the protrusion opening 34 and the bypass pipe 25 opening are connected by tightening with a cap nut 35.

A check valve 38 consisting of a ball 36 whose specific gravity is slightly larger than that of water and a valve seat 37 is provided midway through the flow path 32 within the hollow cylindrical body 33.

39 is a pin that prevents the ball from being removed, 40 is a seal ring, 4
Reference numeral 1 denotes a hole that connects the throat cylinder 33 upstream of the valve seat 37 and the gap formed between the inner wall of the protrusion 31 .

42 is a bypass flow rate regulating hole provided in the temperature control valve 26, and 43 is a flow rate regulating hole to the heat exchanger 5.

The present invention has the above-described configuration. To use the water heater, the operation shaft 15 is operated to open the safety valve 16 and the pilot valve 17, the pilot burner 7 is ignited, and the main valve 18 is opened.

Then, when the hot water tap 30 is opened, a water flow is generated in the water supply pipe 14,
The differential pressure type hydraulic response device 23 operates to open the hydraulic gas valve 19, and the gas flows to the burner 6, which burns it.
Heat exchanger 5 is heated to send heated water into mixing fitting 29, where it is mixed with cold water sent from bypass pipe 25 to supply hot water at an appropriate temperature.

In addition, to stop using the water heater, close the hot water tap 30, the flow of water in the water supply pipe 14 will stop, the hydraulic response device 23 will stop operating, the hydraulic gas valve 19 will be closed, and the burner 6 will start heating. will be stopped.

However, in this type of water heater, even if the hot water tap 30 is closed, there is a certain time delay before the burner 6 stops burning, and the residual heat in the heat exchanger 5 causes the hot water in the heat exchanger 5 to rise further. The heated hot water expands and enters the mixing fitting 29 from the hot water supply pipe 28, and from there flows back through the bypass pipe 25 and enters the hydraulic response device 23.

Therefore, the pressure safety valve 17 remains inoperable because the operating pressure cannot be obtained, and the hot water flowing back into the hydraulic response device 23 causes premature aging of the diaphragm that constitutes the device 23, and furthermore, the hydraulic response device 23 malfunctions. This could lead to overpressure inside the casing, which could lead to an explosion.

However, according to the present invention, since the check valve 38 is interposed in the bypass pipe 25, even if hot water flows backward through the bypass pipe 25, the ball 36 contacts the valve seat 37 and closes the flow path 32. Backflow to the hydraulic response device 23 is prevented, and sufficient operating pressure can be applied to the pressure safety valve 17, making it possible to ensure the safety of the appliance due to after-boiling.

As described above, the present invention has great effects not found in conventional water heaters, but in this embodiment, a check valve is further provided to prevent the expected deterioration of drainage performance.

That is, the interior of the water unit such as the hydraulic response device 23 has poor drainage performance, and in order to completely drain the interior of the unit, it is essential that air enters through the bypass pipe.

According to this embodiment, the atmosphere from the bypass pipe can enter the hydraulic response device 23 through the hole 41 from the gap between the cylinder body 33 and the inner wall of the protruding part 31, and will not have any adverse effect on drainage performance. be.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram showing an embodiment of the present invention, and FIG. 2 is a sectional view of the main parts. 5... Heat exchanger, 14... Water supply pipe, 1
9...Hydraulic gas valve, 22...Gas valve unit, 23...Hydraulic response device, 25...
...Bypass, pipe, 27...Water unit, 28
...Hot water pipe, 38...Check valve.

Claims (1)

[Scope of utility model registration request] A water supply pipe is connected to the heat exchanger via a differential pressure type hydraulic response device equipped with a diaphragm placed above the heat exchanger, and the hot water supply pipe is connected above the heat exchanger, and pressure is applied to the water supply pipe. A safety valve is provided, and a bypass pipe is branched from the water supply pipe downstream of the hydraulic response device and connected to the hot water supply pipe, and the bypass pipe is provided with a check valve to prevent water from flowing to the water supply pipe side. A stationary water heater characterized by: