JPH0629651B2 - Steam generator - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steam generator for heating a bathroom air or the like by filling a bathroom or the like with steam and using it for a sauna or the like.

2. Description of the Related Art In general, a steam generator of this type for boiling water to generate steam has a can body 24, a steam outlet 26 in an upper space of the can body 24, and a lower water body as shown in FIG. Water supply port 25
A drain port 31 is provided at the bottom of the can body 24, and an electric heater 23, which is a heating source in the can body 24 and is located in the water, is provided. The electric heater 23 generates heat to heat the water 34 in the can body 24. Then, it is boiled to generate steam 35, and the steam 35 is sent out from the steam outlet 26 through the steam pipe 30. The steam pipe 30 is arranged and opened to the atmosphere such as a bathroom. Further, the drainage pipe 32 connected to the drainage port 31 and the drainage valve 33 drain the water 34 in the can 24.

In the above configuration, the water 34 in the can 24 is reduced by continuously generating steam, but the water level sensor 27 and the sewage level sensor 28 provided in the can 24 constantly maintain the water level. Water is replenished into the can body 24 from the water supply port 25 so as to keep the water level sensor within the range. Since the water 34 in the can body 24 is constantly boiling and evaporating, scale components (calcium, magnesium, silica, etc.) contained in the water are deposited and concentrated, and the can body 2
4 and the surface of the electric heater 23. Fifth
Shown in the figure. The water 34 in the can 24 is discharged from the drain valve 33 when the steam generator is stopped. This is to drain the water in which the scale components are concentrated to reduce the scale adhesion. Stopping the steam generator is to turn off the electric power to the electric heater 23. By this operation, the pressure P ₂ in the can body 24 is rapidly decreased because the tip of the steam pipe 30 is opened, and the drain valve is discharged. The pressure applied to 33 is only at the HmmH ₂ Oe point, which is the position head, as shown in FIG. On the other hand, the can 24 and the electric heater 23 are cooled and contract at the stop d point of the steam generator. At this time, due to the difference in thermal expansion coefficient between the can 24 and the electric heater 23 and the attached scale 37, the scale 37 is peeled off to become a scale piece 37 ′, which falls and is deposited on the lower portion of the can 24. The scale piece 37 'that has fallen near the drainage port 31 is discharged outside the device together with the drainage point f.

Problems to be Solved by the Invention However, since the scale piece 37 'has a specific gravity of about 2 that is larger than the specific gravity of water 1, the scale piece 37' remains sunk and is not completely discharged by the pressure of the water head H at the time of drainage, and is gradually accumulated on the can body. did. In order to solve this problem, a pump 36 is provided downstream of the drain valve 33.
There was a method of forcibly pulling and draining, but
The scale piece had a problem of being caught in the pump 36.

The present invention solves the above conventional problems, and an object of the present invention is to prevent the scale pieces from accumulating in the can body with a simple device without providing a drainage pump.

Means for Solving the Problems In order to solve the above problems, the present invention provides a can body having a steam outlet and a water supply port, a heating source for heating the can body to boil the water inside, and a can. A water supply can for sending water to the body, a drain pipe and a drain valve for draining water from the can body, and a delay means for delaying and stopping the heating source during drainage after opening the drain valve are provided.

Operation According to the present invention, the drain valve is opened by the stop operation of the steam generator by the above-mentioned configuration, but since the stop of the heating source is delayed from the opening of the drain valve, the pressure inside the can does not drop sharply and the pressure remains Since it is maintained, the drainage is vigorously discharged, and the scale pieces accumulated in the can can be efficiently discharged.

Embodiment An embodiment of the present invention will be described below with reference to the accompanying drawings. In FIGS. 1 to 3, a burner 1 as heating means is arranged below a can body 2 with a constant combustion space. In the can body 2, a steam outlet 5 in the upper space, a water supply port 4 in the lower water, and a water level sensor 6 for controlling the opening and closing of the water supply valve by a water level signal to keep the water level in the can body 2 within a certain range. A sewage level sensor 7 is provided, and a large number of fins 3 that absorb the combustion heat of the burner 1 are welded to the outer peripheral surface of the can body 2. Further, a water supply pipe 8 connected to the water supply port 4 of the can 2 and a drainage port 9 branched from the water supply pipe 8 are provided with a drainage pipe 21 and a drainage valve 12 is provided in the middle thereof. Four
Reference numeral 0 denotes a control device, which opens the drain valve 12 when the operation stop switch 41 is operated, and delays the delay means 42 after this.
A signal is sent to the solenoid valve 43 to control the burner 1 to stop the combustion. The drain valve 12 comprises a motor 17, a shaft 16, a ball 13, a valve seat 14 and a packing 15.

In the above configuration, the fins 3 absorb the combustion heat of the burner 1 by the combustion of the burner 1, the water 19 in the can body 2 is heated and boils, and the steam 20 is generated. The generated steam 20 is
From the steam outlet 5, it is sent out through the steam pipe 18. The steam pipe is extended and opened to the atmosphere in the bathroom. Although the water 19 in the can body 2 evaporates and decreases, water is replenished from the water supply port 4 so that the water level is kept within the range where the upper water level sensor 6 and the lower water level sensor 7 are located. Since the water 19 in the can body 2 is boiling and evaporating, P
A pressure of ₁ is applied. Further, in the water 19 in the can body, scale components contained in the water are deposited and concentrated, and the scale adheres to the inner wall of the can body 2 (shown in FIG. 2). When the stop switch 41 is operated to stop the steam generator (point a) as shown in FIG.
A signal is input to 7 to drive the drain valve 12 to open, and the water in the can body 2 is vigorously drained through the drain pipe 21 by the vapor pressure P ₁ . Then, when the stop switch 41 is operated, the delay means 42 of the control device 40 operates to extinguish the fire of the burner 1.
Within 3 seconds after opening the drain valve 12, a signal is input from the control device 40 to the solenoid valve 43 to close it, and the supply of gas is stopped. This is to maintain drainage pressure. Therefore, the water 19 in the can 2 is drained to extinguish the burner 1,
When the steam generator stops completely, the can body 2 is rapidly cooled and contracts. At this time, the scale 2 attached to the can body 2
Due to the difference in the coefficient of thermal expansion of 2, the scale 22 is peeled off and becomes a scale piece 22 ', which falls to the bottom of the can body 2. The scale piece 22 ′ that has fallen is discharged outside the device through the drain valve 12 together with the water 19 in the can body 2 during the drainage described above. The drainage pressure P ₁ inside the can decreases a little as the drain valve 12 opens, but because the fire extinguishing (point b) of the burner 1 is delayed, there is no decrease as in the conventional example, and the pressure is maintained. However, since the water is drained, the drainage and the scale pieces are efficiently discharged, and the scale pieces 22 'are not deposited in the can body.

In the embodiment, the burner was extinguished within 3 seconds after opening the drain valve, but the burner can be fired arbitrarily within a range that does not result in an empty state due to the amount of water in the can and the steam generation capacity of the steam generator.

Effects of the Invention As described above, according to the present invention, the following operational effects can be expected.

(1) During the drainage after the drain valve is opened, the heating source stops heating after a delay, so there is no sudden drop in the pressure inside the can during drainage, and the drainage and scale piece discharge efficiency is high, and the scale inside the can Accumulation can be prevented.

(2) The drainage pump is not required, the scale is not caught in the pump, and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a steam generator showing an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along the line AA in FIG. 1, and FIG. FIG. 4 is a vertical cross-sectional view of a conventional example, FIG. 5 is a cross-sectional view showing the state of scale adhesion and peeling on the inner wall of the can and the heater surface of FIG. 3, and FIG. 6 is the internal pressure of the can. It is a figure which shows the change of and the progress of time. 1 ... Burner (heating source), 2 ... Can body, 4 ... Water inlet,
5 ... Steam outlet, 8 ... Water supply pipe, 12 ... Drain valve, 21
…… Drainage pipe, 42 …… Delay means.

Claims (1)

[Claims] 1. A can body having a steam outlet and a water supply port, a heating source for heating the can body to boil the water inside, a water supply pipe for feeding water to the can body, and drainage for draining water from the can body. A steam generator comprising a pipe, a drain valve, and a delay means for delaying and stopping a heating source during drainage after opening the drain valve.