JPS589153Y2 - Karadakiboushisouchi - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of an empty heating prevention device used in a bathtub or the like.

FIG. 1 shows a bathtub connected to a bathtub 1 by an up-and-down circulation pipe, 3 is an overheating prevention device attached to the heat exchanger 2 of the bathtub 4, and 3a is a side surface below the heat exchanger 2. 3b is a connecting pipe having a smaller cross-sectional area than the air chamber, and 3d is a water pressure switch having a diaphragm 3C stretched therein.

In the conventional dry firing prevention device 3, as shown in Fig. 2, water 2a in the heat exchanger 2 enters the air chamber 3a, so the air in the air chamber 3a is compressed, and the compressed air is sent to the water pressure switch 3d.
Since it works to push up the diaphragm 3C inside,
As a result, the contacts in the solenoid valve circuit are closed, and the electromotive force generated by the heating of the thermocouple by the pilot burner opens the solenoid valve and ignites the main burner.

(Solenoid valves, solenoid valve circuits, contacts, thermocouples, pilot burners, etc. are not shown.

) Therefore, if there is no water in the heat exchanger 2, the air will not push up the diaphragm 3C, so the contacts in the solenoid valve circuit will be opened, and no gas will flow to the main burner 7, preventing the bathtub from heating up empty. .

However, in the conventional dry firing prevention device 3, a predetermined amount of air needs to be secured in the air chamber 3a and the connecting pipe 3b in order to reliably operate the water pressure switch 3d, but the water temperature in the heat exchanger 2 When the water rises, water vapor is generated in the air chamber 3a, and as time passes, the air and water vapor in the air chamber 3a are replaced.Furthermore, this water vapor rises through the connecting pipe 3b, during which it is cooled and returns to water.

However, if this phenomenon continues, the air will dissolve into the water and the amount of air will decrease, conversely the water level will rise, and eventually the air will not have enough pressure to push up the diaphragm 3C and will no longer be able to keep the contacts closed. However, there is a drawback that combustion stops even though there is water in the bathtub 1, which causes a malfunction.

The present invention was developed in view of the above-mentioned drawbacks, and the purpose is to provide a dry firing prevention device that does not malfunction and can be used with peace of mind, and its gist is as follows:
The air chamber is positioned higher than the connection opening on the heat exchanger side of the air chamber, and the upper air chamber is connected to flow 1, which rises and falls depending on the water level flowing into the air chamber and covers the water surface and is in close contact with the inner wall of the air chamber. The reason is that it was brought to the surface of the water.

An embodiment of the present invention will be described below with reference to FIG.

2 is a heat exchanger installed in the bathtub and connected to the bathtub 1 by a circulation pipe! 3a is an air chamber in which an L-shaped metal tube is connected upward from the lower side of the heat exchanger 2, and the upper part of the tube is an air reservoir, and a water pressure switch 3d is installed in the upper part of the air chamber 3a. A connecting pipe 3b having a smaller cross section than the air chamber 3a communicating with the air chamber 3a is connected thereto.

3e is made of synthetic resin etc. with a specific gravity of 1 or less,
The float is sized to follow the water level flowing into the air chamber 3a, cover the water surface, and come into close contact with the inner wall of the air chamber 3a.

That is, when the water 2a of the heat exchanger 2 enters the air chamber 3a, the flow 3e rises according to the water level and reaches a certain water level in the air chamber 3a.

Then, the air in the air chamber 3a and the connecting pipe 3b is pressurized,
The air pressure causes the diaphragm 3 in the water pressure switch 3d to
Press C to ignite twin burner 7.

Then, the temperature of the water in the heat exchanger 2 rises and the temperature in the air chamber 3a also rises, but it flows to the water surface in the air chamber 3a)3
Because e is floated, almost no water vapor is generated.

Therefore, since the present invention has the above-mentioned configuration, no water vapor is generated even if the water temperature in the air chamber rises, and the displacement phenomenon of air and water vapor is prevented, and a fixed amount of air is always held in the air chamber, resulting in malfunctions. will no longer occur.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of the connection between a bathtub and a bathtub equipped with a dry-heat prevention device, Figure 2 is a partial cross-sectional view of the air chamber of a conventional dry-heat prevention device, and Figure 3 is a diagram based on the present invention. It is a partial cross-sectional view of the air chamber portion of the dry firing prevention device. Explanation of symbols 1...Bathtub, 2...Heat exchanger, 2a...Water, 3...Dry heating prevention device, 3a...・Air chamber, 3b...Connecting pipe, 3C...Diaphragm, 3d...Water pressure switch, 3e...Float, 4...
・Bath pot, 5...cock, 6...knob, 7...main burner.

Claims (1)

[Scope of utility model registration request] An air chamber that bends upward is protruded from the lower side of a heat exchanger such as a bath kettle, and the upper part of the iron base and a diaphragm are built in, and the water pressure switch that opens and closes the contacts of the solenoid valve circuit has a smaller cross-sectional area than the iron base. In a dry firing prevention device connected by a connecting pipe having A dry firing prevention device characterized by comprising a float that is in close contact with the inner wall of the air chamber and floats on the water surface of the air chamber.