JPH0221101A - Steam generator - Google Patents

Abstract

PURPOSE:To prevent the generation of scale layer adhered on the surface of a heater and enable the discharge of said scale to the outside of a steam generation device by installing a water supply valve to a first tank, providing a water heating means inside a third tank, and installing a water discharge valve to either forward connection part which connects a second tank with a third tank or a third tank. CONSTITUTION:A third tank 19 equipped with a heating means 28 is installed, and it is separated from a second tank 16 which directly generates steam while a third tank 19 is connected with the second tank 16 by a forward connection part 22 and a return connection part 23 in an effort to generate a circulating convection flow. This construction makes it possible to extremely reduce scales adhered mainly on the internal surface of the third tank 19. As a result, a heating means of a plane heater can transfer heat to water smoothly, which maintains its steam generation capacity without drop even if it is used for long time. In addition, the installation of water discharge valve 26 can discharge smashed scales outside. Furthermore, if a water supply valve 24 of a first tank 14 is designed variable in terms of its flow rate, the generation of steam will not be interrupted on its way even if water is refilled.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a steam generator for filling a domestic bathroom or the like with steam and using it as a sauna room.

BACKGROUND OF THE INVENTION Conventionally, this type of steam generator has had a structure as shown in FIG. 5 or 6, for example.

That is, in FIG. 5, a heater 2 and a water level sensor 3 are provided in a tank 1, a water supply valve 4 connected to the tank 1 is controlled by a signal from the water level sensor 3, and a steam supply pipe provided at the top of the tank 1 is connected to the water supply valve 4 connected to the tank 1. Steam is supplied through 5.

In addition, in FIG. 6, the first tank 6 is provided with a water level sensor 7, the second tank 8 is provided with a heater 9, and the first tank 6 is provided with a water level sensor 7.
The upper and lower parts of the tank 6 and the second tank 8 are connected by a steam communication pipe 10 and a hot water storage communication pipe 11, respectively, and the water supply valve 12 connected to the first tank 7 is connected to the water level sensor 7. It is controlled by a signal and is configured to supply steam through a steam supply pipe 13 provided at the upper part of the second tank 8.

Problems to be Solved by the Invention However, in the structure shown in Fig. 5, the water temperature in tank 1 is around 100°C while steam is being generated, so it is in a boiling state, so the situation inside tank 1 is as follows. It shakes violently up and down, which causes the water supply valve 4 and the heater 2, which are activated by the signal from the water level sensor 3, to malfunction, making it difficult to supply stable steam. Furthermore, since the temperature of the water in the tank 1 is always high, the inner surface of the tank 1, the heater 2, and the water level sensor 3 that are submerged in the water are mainly composed of calcium carbonate, etc. contained in the water. Scale precipitates and adheres. (The higher the hot water temperature, the more the amount of scale precipitation tends to increase.) In particular, if the scale is deposited on the surface of the heater 2, heat conduction becomes poor, the steam rise time becomes longer, and the amount of steam supplied increases. further decreases, the heating heater 2
There was a problem with the wire breaking. On the other hand, if the water level sensor 3 was also adhered to and laminated in the same way, there was a problem that the control of the water supply valve 4 and the heater 2 would become unstable and eventually become uncontrollable. The difference between FIG. 6 and FIG. 5 is that the first tank 6 provided with the water level sensor 7 and the second tank 8 for heating are separated. The water temperature in the first tank 6 is much lower than that in the second tank 8, which is equipped with a heater 9 and reaches a boiling state, and the water adheres to the surface of the water level sensor 7. The amount of scale is reduced, and therefore the heater 9 and the water supply valve 12 can be controlled stably.

However, scale still precipitates and adheres to the surface of the heater 9 provided in the second tank 8 for generating steam, resulting in the same problem as in the case of FIG. 5. Furthermore, there was also the problem that steam generation temporarily stopped while water was being supplied.

Therefore, the first object of the present invention is to obtain a steam generator in which scale is not deposited on the surface of the heater. The second purpose is to release the crushed scale to the outside of the steam generator. The third purpose is to ensure that steam generation is not interrupted even during water supply.

The fourth purpose is to speed up the steam generation rise time and to make the scale more finely pulverized.

Means for Solving the Problems In order to achieve the above-mentioned first object, the present invention provides a third tank provided with heating means.

In order to achieve the second object, the present invention provides a third tank and a piping system connected to the third tank with a drain valve.

Furthermore, in order to achieve the third object, the present invention makes the water supply valve variable in flow rate.

Furthermore, in order to achieve the fourth object, the present invention also provides the third object.
Tanks are connected in series, in parallel, or in series and parallel.

Operation The steam generator of the present invention has three tanks with the above configuration.
The liquid level of the first tank, which is divided and equipped with a water level sensor, is directly connected to the second tank, which has a liquid level that generates steam, through a hot water storage communication pipe that is a hot water storage communication part and a steam communication pipe that is a steam communication part. Therefore, the liquid level is the same as that of the second tank. Further, the hot water temperature in the first tank is lower than the hot water temperature in the second tank. Therefore, no steam is generated from the liquid level in the first tank. In addition, steam is generated from the liquid level of the second tank, and the liquid level is shaking violently. Despite this change in head pressure in the second tank, the difference between the first tank and the second tank
Since the tanks are connected by a hot water storage communication pipe with high pipe resistance, disturbances in the liquid level in the second tank are not transmitted to the first tank, and the liquid level in the first tank can be kept level.

As a result, the reliability of control by the water level sensor can be improved.

On the other hand, when the water is heated in the third tank, as the temperature increases, the nucleate boiling phenomenon on the inner surface of the third tank becomes more and more intense, and as a result, the third tank, the second tank, and these A flow is generated due to the circulatory system flow, which is composed of an outgoing connection pipe, which is an outgoing connection part, and a back connection pipe, which is an incoming connection part. This convection flow naturally extends into the tank of cylinder 3, and the effects of both this convection flow and the nucleate boiling phenomenon change the environment within the third tank, where scale is most likely to occur at high temperatures. . In other words, scale is less likely to deposit and adhere in the third tank.
Or even if it is deposited and deposited, it is peeled off and crushed into small pieces.

Further, by providing a drain valve, finely pulverized scale can be discharged to the outside.

Further, by setting the water supply valve to a large flow rate and operating the water supply valve and the drain valve in conjunction with each other, the interiors of the first tank to the third tank can be efficiently cleaned. Furthermore, if the water supply valve is set to a small flow rate so that the flow rate is approximately balanced with the amount of steam generated while steam is being generated, steam generation will not be interrupted even during water supply.

Furthermore, if a plurality of third tanks are connected in parallel or in series, the power will be increased and the flow velocity flowing through the circulation system channel will further increase. As a result, the effect of reducing scale adhesion and the ability to crush scale are improved.

Embodiment A first embodiment of the present invention will be described below with reference to the accompanying drawings. In FIGS. 1 and 2, a water level sensor 15 is provided in the first tank 14, and the upper and lower parts of the second tank 16 are connected by a steam communication pipe 17 and a hot water storage communication pipe 18, respectively. A third tank 19 is provided at the bottom of the second tank 16, and a circulating water inlet 20 provided at the bottom of this third tank 19 and a boiling water outlet 21 provided at the top are connected to the second tank 16. They are connected by an outgoing connection pipe 22 and a rear connection pipe 23, respectively.

A water supply valve 24 is connected to the first tank 14, and a steam supply pipe 25 is connected to the upper part of the second tank 16.

Furthermore, a drain pipe 27 equipped with a drain valve 26 is branched from the outgoing connecting pipe 22 at a lower position of the third tank 19 .

At the bottom of the third tank 19, a heating means (hereinafter referred to as a plane heater) 28 for heating the tank is provided in close contact with the lower surface of the third tank 19.

Reference numeral 29 denotes a holding plate that brings the flat heater 28 into close contact with the lower surface of the third tank 19, and 3o denotes a lead wire of this lower heater 28. Further, 31 is a control unit for driving and controlling the water supply valve 24 and the lower heater 28 based on the electric signal from the water level sensor 15.

Next, the operation of the configuration of this embodiment will be explained. First, a case will be described in which water is supplied to the first tank 14 up to a predetermined water level and steam is being sent through the steam feed pipe 25. The third tank 19 is heated by the plane heater 28.
When heated, the water inside continues to boil, and the boiling water exits the boiling water outlet 21 and passes through the rear connecting pipe 23.
It enters the second tank 16. Then, the second tank 16
A part of the stored hot water flows into the third tank 19 through the outgoing connection pipe 22 and the circulating water inlet 2°, where it is further heated and flows out into the second tank 16. In this way, convection circulating water flows inside the third tank 19. Second tank 16
A large amount of steam is generated from the internal liquid level, and is supplied to the bathroom (sauna room) through the steam supply pipe 25 while maintaining a predetermined pressure.

Since the upper portions of the first tank 14 and the second tank 16 are connected by a steam communication pipe 17, the pressures in both tanks are the same. This keeps the liquid levels in the first tank 14 and the second tank 16 constant.

When the liquid level in the first tank 14 gradually falls in proportion to the amount of steam supplied, a water level lower limit signal is input from the water level sensor 15, and the control unit 31 sends an electric signal to open the water supply valve 24. When water is supplied to the upper limit of the water level of the water level sensor 15, the water supply valve 24 is closed and the water supply is stopped. Next, the case where steam generation is stopped will be explained.

The drain valve 26 is opened after the use of the steam generator of the present invention is completed, and the drain valve 26 is opened to drain the first tank 14, the second tank 16, and the third tank.
The scale particles or scale pieces that have become fine and are floating in the tank 19 are discharged. When using in an area with particularly poor water quality (for example, so-called high hard water quality with high calcium and magnesium components such as the Okinawa area), open the water supply valve 24, supply water, and then open the drain valve 26. It can also be operated repeatedly to clean the inside of the tank.

Next, the function of the third tank 19 will be explained.

FIG. 2 is an enlarged view of the third tank 19, and the lower half is a sectional view of the main part thereof. As is clear from this figure, the third
This third tank 19 is configured to have an inner cylindrical shape.
Heat is transferred to the stored hot water from the bottom surface of the third tank 19, on which a flat heater 28 is provided in close contact with the bottom surface of the third tank 19. During steam generation, nucleate boiling occurs at the bottom of the third tank 19, and in such a state, convection water flows from the circulating water inlet 20 of the third tank 19.
Internal heat transfer, hot water flow, and scale precipitation phenomena have become even more complex. That is, even if scale is deposited and tries to adhere to the inner bottom surface of the third tank 19, the generated scale pieces are crushed by the flow pressure or disturbance caused by this circulation convection. Note that the third tank 19 of the present invention
The mounting positions of the circulating water inlet 20 and the boiling water outlet 21 are not vertically symmetrical as shown in FIG. It is structured so that it is stronger.

Note that if the capacities of the second tank 16 and the third tank 19 are made as small as possible without changing the heat generation capacity of the lower heater 28, the steam rise time at the start of use tends to become shorter.

As a result, scale does not adhere to the inside of the third tank 19, or even if it does, it is immediately peeled off and crushed, so that the ability to generate steam does not decrease. Further, since heat conduction from the planar heater 28 is performed smoothly, the planar heater 28 will not overheat and disconnect.

Furthermore, since the planar heater 28 is used instead of the conventional sheathed heater, the third tank 19 can be configured to be thin, and the entire steam generator can therefore be made smaller and lighter.

Next, a second embodiment of the steam generator of the present invention will be described based on FIG. 3. In the embodiment shown in FIG. 3, the same parts as in FIG. 1, which is an explanatory diagram of the first embodiment, are given the same reference numerals and the explanation thereof will be omitted.

The second embodiment differs from the first embodiment in that a second water supply valve 32 is provided in parallel with the water supply valve 24.

The operation will be described using the water supply valve 24 for a large flow rate and the second water supply valve 32 for a small flow rate.

The large flow rate water supply valve 24 is opened and activated when the steam generator (FIG. 3) is started to be used, and when the drain valve 26 is opened to clean the inside of each tank after use.

Further, the second water supply valve 32 for small flow rate opens and operates when a steam generator is used.

As a result of the above, water is supplied in a short time at the beginning of use, so it can be used sooner.

Also, after use, the water supply valve 2 can be connected in conjunction with the drain valve 26.
By operating No. 4, the cleaning time is shortened and the flow rate is high, which improves the cleaning effect.

In addition, while the steam generator is in use, the water supply valve 24 is closed and the second water supply valve 32 with a small flow rate opens and closes to supply water, so this small flow rate of water supply is used as a flat heater to heat the third tank 19. If the setting is made in advance so as to be almost balanced with the heating capacity of the steam supply pipe 28, the steam from the steam supply pipe 25 will not be temporarily interrupted even when water is being replenished.

Although two water supply valves are used in the embodiment shown in FIG. 3, it is also possible to provide one water supply valve having a function of switching between large and small flow rates. Furthermore, since the temperature of the water supply changes with seasonal changes, a water flow proportional control valve can also be used that can vary the flow rate accordingly.

Furthermore, a third embodiment of the steam generator of the present invention will be described based on FIG. 4. In FIG. 4, the same components as those in the first embodiment and the second embodiment have been omitted. Also the fourth
Among the constituent elements shown in the figures, the same parts as in the first embodiment are given the same reference numerals, and the explanation thereof will be omitted. As is clear from FIG. 4, in the first embodiment and the second embodiment, the third tank 19 and the plane heater 28 were each composed of one, but in the third embodiment, the plane heater 28 A fourth tank 33 having the same shape (rotated by 180° in the figure and connected) and the same capacity as the third tank 19 equipped with 28 is connected in series to the third tank 19. A fifth tank 36 and a sixth tank having the same shape and the same capacity are provided with a plane heater 28 between the second outgoing connecting pipe 34 branched from the second outgoing connecting pipe 34 and the outgoing connecting pipe 35 connected from the second tank 16. 37
are connected in series.

When the above configuration is adopted, that is, when the third tank 19 and the fourth tank 33 are connected in series, the boiling phenomenon is further amplified, and therefore the third tank 19 and the fourth tank 33 The flow velocity of the circulating convection flowing inside increases. However, if too many connections are made in series, an excessive temperature rise prevention device (not shown) provided in the third tank 19 will be activated, so in such a case, the fifth tank 36 and the sixth tank 37
After connecting them in series, they are configured to be connected in parallel. As a result, an environment is created in which scale precipitation and adhesion to the third tank 19 and the fourth tank 33 is more difficult to occur, or even if scale occurs, the crushing capacity is further increased, so even if used for a long time, the steam No reduction in performance due to scale adhesion to the generator or failure due to overheating of the flat heater 28 will occur. Note that the first tank, second tank, and third tank may be separated and communicated with each other as in the first to third embodiments, or the three tanks may be integrally molded. Then, it can be partitioned later into three tanks, or any two of the three tanks can be integrally molded and then partitioned.

Effects of the Invention As described above, the present invention provides a third tank equipped with a heating means to be separated from the second tank that directly generates steam, and to separate the third tank and the second tank. By connecting at the outgoing connection and the inbound connection and causing a circulating convection flow, scale adhesion mainly in the third tank is extremely reduced.

As a result, heat transfer from the heating means of the flat heater to the water occurs smoothly, so even after long-term use, there is no reduction in steam generation capacity or failure of the electric heater, which is the case with conventional heaters, resulting in long-term reliability. This makes it possible to provide superior equipment.

Further, reliability can be further improved by providing a drain valve to drain the crushed scale every predetermined cycle.

Furthermore, by making the water supply valve variable in flow rate, the inside of each tank and connecting pipe can be efficiently cleaned, and even if water is replenished during steam generation, steam generation will not be interrupted midway.

Furthermore, if the third tank is configured in series, in parallel, or in both series and parallel configurations, the strength of the circulating convection flowing within the tank increases accordingly, and as a result, the effect of preventing scale adhesion is further increased. Alternatively, it has the effect of increasing the ability to exfoliate and crush scale even under conditions where scale precipitation is difficult to avoid in water areas where calcium components are particularly high.

[Brief explanation of the drawing]

FIG. 1 is a system configuration diagram of a steam generator according to a first embodiment of the present invention, FIG. 2 is a sectional view of main parts of a third tank and heating means of the same device, and FIG. 3 is a system configuration diagram of a steam generator according to a first embodiment of the present invention. FIG. 4 is a system configuration diagram of a steam generator according to the third embodiment of the present invention, FIG. 4 is a system configuration diagram of main parts of a steam generator according to a third embodiment of the present invention, and FIGS. FIG. 14...First tank, 16...Second
Tank, 17... Steam communication pipe, 18...
...Hot water storage communication pipe, 19...Third tank, 22
...Outgoing connection pipe, 23...Return connection pipe, 2
8...Flat heater. Name of agent: Patent attorney Shigetaka Awano, figure 1, figure 14... Tank figure of 7?1

Claims (6)

[Claims] (1) A first tank equipped with a water level sensor that detects the water level, a second tank connected to a steam feed pipe that sends steam, and the upper parts of the first tank and the second tank are connected. a steam communication section that connects a lower part of the first tank and the second tank; an outgoing connection section and an incoming connection section that are connected to the second tank; A steam generation device comprising: a third tank connected between the second tank and the second tank; and a heating means for heating water in the third tank. (2) The steam generator according to claim 1, further comprising a drain valve provided in at least one of the outgoing connection section or the inbound connection section connecting the second tank and the third tank, or the third tank. (3) The steam generator according to claim 1, wherein a water supply valve for supplying water to the first tank is provided, and the water supply valve has a variable flow rate. (4) The steam generator according to claim 1, wherein a plurality of third tanks are connected in series. (5) The steam generator according to claim 1, wherein a plurality of third tanks are connected in parallel. (6) The steam generator according to claim 1, wherein a plurality of third tanks are connected in series and in parallel.