JPS6273008A - Home-use bath furnace - Google Patents

Abstract

PURPOSE:To reduce a decrease in temperature when a burner is diminished and to decrease a cost of fuel by a method wherein a cap which can be opened or closed is arranged at a combustion air inlet or outlet port of a home-use external bath furnace. CONSTITUTION:A cap which can be opened or closed is arranged at a suction port for combustion air to a home-use external bath furnace and a discharging port for a waste combustion gas, whereby the degree of of opening of a cap which is arranged at an air inlet or outlet opening can be adjusted manually or automatically as the burner is ignited or diminished. For example, a circular cap 10 is arranged below a diluted air suction port 9 of a discharging cylinder 6 in such a way as it may be rotated around a shaft 11, and stoppers 12 are arranged at both right and left sides. As a result, when the burner is diminished, no or scarce flow of air under a conventional draft effect is present, so that a heat exchanger is not cooled by the flowing air. Owing to this fact, a decrease in temperature of hot water is small and a cost of fuel is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a household bathtub, and more specifically, to an outer pot type pot.

(bl) Conventional technology Household bathtubs are more commonly known as outer pot types rather than inner pot types that directly heat the bathtub, such as the so-called Goemon baths.

The principle of this is that, as shown in Figure 1, the bathtub (1) and the pot (2) are separated and a pipe is connected between them. The pot (2) is equipped with a burner (3 burners) and a heating heat exchanger (4).
It consists of an air suction port (5) and an air exhaust port (6).

When the burner is ignited now, the water in the heat exchanger (4) will be heated, its density will be reduced, and it will be discharged from the discharge pipe (7) above the bathtub (1). Then, low temperature water is sucked into the heat exchanger (4) from the suction pipe (8). Water circulates according to this principle (thermosyphon). The only energy required for circulation is the difference in the specific gravity of the water. While circulating in this way, the temperature of the bathtub (1) increases.

This outer pot type is now widely used because it allows the pot to be installed outdoors, has a long lifespan since the bathtub is not directly heated, and allows a wide selection of bathtub materials. be.

(C) Problems to be Solved by the Invention The outer pot type described above also has the following drawbacks.

This is the drop in temperature of the hot water when the burner is extinguished. Normally, the temperature of hot water placed in an enamel container installed in a bathroom will only slightly drop over an hour or two.

However, everyone knows from experience that bath water cools much faster than that. The reason for this is as follows. When the burner (3) in FIG. 1 is extinguished, the temperature of the heat exchanger (4) is approximately the same as the temperature of the hot water in the bathtub (for example, 45° C.). Naturally, it is considerably higher than atmospheric salt. In this case, the pot (
2) The air inside is warmed, becomes lighter, and is discharged from the exhaust pipe (6), and cold air (atmosphere) is sucked in through the air intake port (5). Therefore, the heat exchanger (4) is cooled by the cold air and becomes lower than the temperature of the hot water in the bathtub (1). This happens when,
Convection in the opposite direction to that during heating occurs, and hot water with high temperature is sucked in from the discharge pipe (7), and cooled water is discharged from the suction pipe (8). Due to this reverse convection, cooling progresses further, and the heat exchanger (4) is always at the temperature of hot water.
Theoretically, the pot (2) will continue to draw in air until the temperature of the hot water reaches the ambient temperature. For this reason, the temperature of the bathtub will drop at a rapid rate.

These problems have become even more serious in modern households because the difference in bathing time between children and husbands who come home late has become larger. In other words, it is a complete waste of fuel costs and has a big impact on household budgets. Furthermore, it is extremely large in cold regions such as Tohoku and Hokkaido where the atmospheric temperature is low.

In order to prevent this reverse circulation (convection) of water, it has recently been devised to install a cover made of rubber or Teflon that serves as a check valve inside the bathtub on the outlet side of the discharge pipe (7). This lid allows free flow of water from the discharge pipe (7) into the bathtub (11), but does not allow it to flow in the opposite direction.With this lid, the water does not circulate in the reverse direction, reducing the cooling caused by the atmosphere as described above. However, this also does not prevent the flow of air within the pot, so it cannot prevent the heat exchanger and the water in it from being cooled. This creates resistance to circulation, slowing down the circulation of water, and increasing the amount of water boiling in the heat exchanger, which wastes heat.

In addition, since water is naturally circulated by thermosiphon,
Check valves must be designed to have as little resistance as possible, and as a result, they are limited to simple valves that have a large backflow prevention effect and cannot be used with gas.

Fdl Means to Solve the Problems In view of the above-mentioned current situation, the inventors of the present invention have completed the present invention as a result of intensive research. The bath kettle is provided with a lid that can be opened and closed at the combustion air inlet and outlet.

As mentioned above, the outer pot type is a type in which the burner does not directly heat the water in the bathtub, but heats it externally and circulates it using the principle of thermosiphon to raise the temperature of the water in the bathtub. There are two types: an outside-fired type and a self-fired type, which differ depending on whether the pot is located outside or inside the bathroom, and the present invention includes both of these types. Furthermore, fuels include city gas, LPG, kerosene, etc., but are not limited thereto.

Here, the combustion air inlet/outlet refers to the combustion air inlet and combustion flame gas outlet of the bathtub. The outlet is usually a chimney. Most of the intake ports do not have special ducts, but in cold regions, there are many types that have ducts installed to allow inhalation from the outdoors.

The lid may be of any type as long as it can close the entrance/exit. The exit side, the entrance side may be closed on both or either side. Of course, it is not necessary to completely seal it. The touch part may be made of any material, such as metal or plastic, as long as it can withstand the temperature.

If the lid is provided only at the exhaust port, since the exhaust pipe is usually provided with a dilution air suction port, it needs to be located closer to the burner than that part. Otherwise, air will be exhausted from the dilution air suction port.

The lid may be opened and closed in any manner, but examples include the following.

+11 Perform manually.

There are two types: a direct type, in which the lid itself is opened and closed by hand, and a remote type, in which the lid is connected to the ignition cock using a wire. In the case of a direct type, the device itself is very simple and only requires a lid, but care must be taken as there are cases where the user forgets to open and close the lid. In the case of a remote type, there is no problem because the lid is opened at the same time as the burner is ignited because it is linked to the cock.

These methods can be easily applied to existing pots.

(2) Method using an electromagnet.

When ignited, an electromagnet works to open the lid. The electromagnet may be supplied with electricity from an external power supply or from electricity generated by a thermocouple.

In addition, the return of the lid (returning to the original position when the electromagnet loses its magnetic force) is easy by using gravity or a force. The signal or electricity to activate the electromagnet can be introduced from a variety of sources, such as the location of the ignition cock, a flame detector, or a temperature sensor on top of the burner. For example, when the ignition cock is in the open position, the electromagnet is activated.If the flame detector detects flame, the electromagnet is activated.If the temperature detector reaches a predetermined temperature or higher, the electromagnet is activated.

(3) Due to the exhaust power of waste gas.

This can be said to be completely automatic, and is normally closed by gravity, spring, etc., and the burner ignites.
When the waste gas rises, its rising force opens the lid. Therefore, it is necessary to have a structure that can be opened from a closed state with very little force, and that cannot be opened by the upward force of air when the burner is extinguished.

According to this method, no other incidental equipment is required, and no human attention is required.

Next, let's talk about safety.

Even if the lid is not closed when the burner is extinguished, the effect of the present invention will not occur and there is no danger. However, if the lid is not opened when the burner is lit, incomplete combustion will occur. Usually, a bathtub is equipped with a flame detector or the like, and a safety mechanism is provided that closes the gas cock when the flame is extinguished. Therefore, in the case of an external firing type, there is almost no problem if the fire is extinguished due to incomplete combustion. However, in the case of self-congratulatory methods, even incomplete combustion for a short period of time is dangerous. Therefore, a safety mechanism may be provided to prevent this.

For example, in the case of various failures, the lid will be opened due to gravity, the rim switch can be opened and closed depending on the position of the lid, or the contact will close only when the lid is open.
For example, the pilot lamp in the bathroom lights up. Of course,
Since this safety device itself is not directly related to the present invention, any safety device may be adopted.

Furthermore, since the pot has a pilot flame, even if the main burner is extinguished, if the pilot flame is lit, the exhaust port cannot be completely closed. However, this is often not a problem as it is usually impossible to close completely. However, in order to prevent incomplete combustion caused by this pilot flame, the opening degree of the lid body should be set to two levels, a certain amount of opening degree should always be ensured, or another part should be provided that is always open. It's okay.

Furthermore, it is also effective to insulate the entire or part of the pot of the present invention. Conventionally, in external pot-type bathtubs, due to the air circulation described above, insulation was either meaningless or had very little effect, so it was pointless to spend money on it. . However, when the present invention is implemented, since there is no air circulation, heat is radiated little by little from the surface of the pot, and heat insulation construction that prevents this also becomes significant. In other words, heat loss can be greatly reduced.

Although various explanations have been made above, the present invention is capable of manually or automatically adjusting the opening degree of the lid provided at the air inlet/outlet as the burner is ignited and extinguished.

tel Embodiment FIG. 2(a) is a schematic sectional view showing an embodiment of the present invention. A circular lid (10) is attached to the lower part of the dilution air suction port (9) of the exhaust pipe (6). 11) is installed rotatably around the center. Further, stoppers (12) are provided on the left and right opposite sides. This is to prevent rotation in the opposite direction and to keep it in place when the burner is extinguished. Therefore, in the figure, the right side of the lid (10) is slightly heavier. FIG. 2(b) is a view obtained by rotating FIG. 2(a) by 90 degrees. The shaft (11) passes through the exhaust pipe (6) and has a lever (13) at its end. This lever (I3)
The lid body (10) can be opened and closed by operating it by hand.

FIG. 3 is a schematic sectional view showing another embodiment of the present invention. A part of the exhaust pipe (6) is formed into a box shape, and a rectangular lid (10) is mounted therein with a shaft (11) provided at a portion eccentric from the center. Since the right side of the shaft is slightly heavier, it is usually located at the position where it is attached to the receiving part (14). When the waste gas comes here, there is a difference in the area that receives the gas on the right and left sides of the shaft, so this lid body (10) rotates counterclockwise and comes to the position shown by the broken line. However, it does not rotate any further due to the protrusion (15). In this example, setting the left and right weights around the axis is important. The design must be such that it rotates open under the rising force of waste gas when the burner is ignited, but does not rotate under the rising force of air when the burner is extinguished.

FIG. 4 is a schematic front view showing still another embodiment.

This is done by connecting the lever to the ignition cock (not shown) with a wire, rather than manually operating the lever as in the example shown in FIG. Therefore, when the ignition cock is rotated to the one-burner ignition position, the wire is pulled, the lever rotates, and the lid inside rotates.

(f) Effects of the invention According to the present invention, when the burner is extinguished, there is no or almost no air circulation due to the conventional draft effect.
The heat exchanger is not cooled by circulating air. Therefore, the drop in temperature of the hot water is extremely small, resulting in a significant reduction in fuel costs.

[Brief explanation of drawings]

Fig. 1 is a schematic sectional view showing a conventional example, Figs. 2(a) and (bl) are schematic views showing an embodiment of the present invention, and Figs. 3 and 4 are schematic diagrams showing still other embodiments. ...Bathtub 2...Kettle 3...Burner 4...Heat exchanger 5...Suction port
6...Exhaust lower...Exhaust piping 8...
- Suction pipe 9... Dilution air suction port 10... Lid body 11... Shaft 12... Stopper 13... Lever 14... Receiving part 15...
·protrusion

Claims (1)

[Scope of Claims] 1. A bathtub for domestic use, characterized in that a lid body that can be opened and closed is provided at the combustion air inlet and outlet. 2. The bathtub according to claim 1, wherein the lid is provided at the combustion air outlet. 3. The bathtub according to claim 1 or 2, wherein the opening degree of the lid can be adjusted. 4. The bathtub according to claim 1, wherein the lid is opened and closed using an electromagnet and a spring. 5. The bathtub according to claim 4, wherein the signal to the electromagnet is emitted from a flame detector. 6. The bathtub according to claim 1, wherein the lid is opened and closed using a wire. 7. The bathtub according to claim 2, wherein the lid is opened and closed by the rising force of combustion waste gas and gravity.