JPH0445302A - Steam generator - Google Patents

Abstract

PURPOSE:To effectively discharge pieces of separated scale out of a heat exchanger by providing a feed water means and a discharge valve in a heat exchanger for heating stored water and generating steam so that the stored water is discharged before it is heated and after it is heated. CONSTITUTION:When a switch 16 for starting operation is turned on, whereupon a controller 18 keeps a discharge valve 15 in an open state for the stoppage of operation so that a feed water valve 2 is opened to effect feeding and discharging water and a water passage from a feed water port 6 to a discharge water port 13 is provided over a bottom 4 so that the pieces of scale 21 having been separated from the inner surfaces 20 during the stoppage are discharged through the port 13. After the lapse of predetermined time, the valve 15 is closed. During the generation of steam, pieces of scale 21 are separated further from the surfaces 20. And when the supply of steam is not required, the switch 16 is turned off to stop the operation, whereupon the controller 18 cuts off a heater 11 and opens the valve 2 and valve 15 to effect feeding and discharging stored water 19, so that the water 19 is discharged together with the water flowing through the water passage.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a domestic steam generator that prevents deterioration of performance and damage to the appliance due to scale.

BACKGROUND OF THE INVENTION Recently, steam generators have been used at home to supply steam to bathrooms for steam baths.

This type of steam generator, as shown in Figure 3,
Water supply port (also drain port) opened at the bottom 42 of the heat exchanger 41
43, a water supply channel 45 equipped with water supply means 44 was connected. Further, the heat exchanger 41 stores a certain amount of water 46 by a water supply means 44, and is heated by a heater 47 provided on the outer periphery to generate steam.

Further, a drain valve 50 is provided in a drain channel 49 that branches from the water supply channel 45 and has a bent portion 48 in the middle, and after the completion of steam generation, the water supply is stopped and the drain valve 50 is opened to drain the stored water 46. At this time, the scale pieces 52 peeled off from the inner surface 51 of the heat exchanger 41 are removed from the heat exchanger 41 by the drainage flow of the stored water 46.
It had been ejected outside.

iI that invention tries to solve! s However, in the above configuration, a large amount of scale pieces 52 that were peeled off during operation as well as during stoppage were deposited inside the heat exchanger 41. Moreover, this large amount of scale pieces 52,
Therefore, in the drainage channel 49 of a normal diameter, the scale pieces 52 overlap the part of the bend 48 where the flow is stagnant, and the drainage channel 49 is clogged.
There was a problem that the equipment could no longer be used properly.

Further, when the heat exchanger 41 is operated with a large amount of scale pieces 52 inside, the peeled scale pieces 52 may adhere to the inner surface 51 again. The adhered scale and peeled scale pieces 52 are deposited on the bottom 4 over the course of use.
2 and the inner surface 51, and the heater 47 and the water storage 46
During the growth of a barrier wall for heat conduction. For this reason, there have been problems in that the heat transfer rate of the heater 47 is deteriorated and the evaporation performance is lowered, and that the heat exchanger 41 is damaged by overheating in areas where the thickness of the obstacle wall is particularly large.

Therefore, in order to solve the above problems, the present invention aims to effectively discharge exfoliated scale pieces from within a heat exchanger.

! Means for Solving Problem 1 In order to achieve the above object, the first means for solving the problem of the present invention is to equip a heat exchanger that heats stored water and generates steam with a water supply means and a drain valve, The stored water is drained both after heating and after heating.

In addition, the second means for solving problem R includes a water supply port connected to a water supply channel having a water supply means and a drain port connected to a drain channel having a drain valve to a heat exchanger that heats stored water and generates steam. They are installed separately to supply water and drain water when not heating.

Effect: The first means described above reduces the amount of exfoliated scale pieces discharged during each drainage process and effectively discharges them.

Further, by the second means, the amount of water to be discharged and the discharge time necessary for discharging the exfoliated scale pieces can be freely set.

EXAMPLE Hereinafter, an example of a steam generator according to the present invention will be described with reference to the drawings.

FIG. 1 shows a first embodiment, in which a water supply valve 2 is provided in the middle of a water supply channel l connected to an external water supply source such as a water pipe, and a heat exchanger 3 is provided.
A water supply port 6 is opened on a wall surface 5 perpendicular to the bottom surface 4 of the water supply channel 1.
Connect. The heat exchanger 3 is connected to a water level detection section 8 through a communication path 7 . The water level detection unit 8 has an electrode 109 m for water level detection in the water chamber 9 . Further, the heat exchanger 3 has a heater 11 that generates heat by electric power wound around the outer circumference, a steam port 12 at the top, and a drain port 13 facing the water supply port 6 at the bottom.

A drain channel 14 is connected to the drain port 13, and a drain valve 15 is installed in the middle.
will be established.

Next, an operation panel 17 equipped with a switch 16 for operating the steam generator is electrically connected to the steam water supply valve 2 and the like and the controller 18. The controller 18 transmits and receives signals to and from the water supply valve 2, etc., and supplies power, etc. in the direction shown at the end of the broken line in the figure.
The controller 18 includes circuits that control various operations described below.

Based on the above configuration, the operation of this embodiment will now be described.

First, when you turn on the switch 16 to start operation,
Upon receiving this signal, the controller 18 causes the drain valve 15 to continue in the open state at the time of stop, and opens the water supply valve 2 to accompany water supply and drainage. Then, as shown by the arrow in the figure, a water flow is created from the water supply port 6 to the drain port 3 in a direction parallel to the bottom surface 4, and the scale pieces 21 that have peeled off from the inner surface 20 during the stoppage are discharged to the drain port 13. . When a predetermined drainage time, which is a time required for discharging the scale pieces 21, has elapsed, the drainage valve 15 is closed.

Then, the heat exchanger 3 stores water I9 up to the upper limit water level of the electrode lO.
If this happens, the water supply will be cut off. On the other hand, before this, the electrode IO
When detects the lower limit water level, the heater 11 is energized and the water storage 1
9 is heated and boils to generate steam.

When the stored water 19 decreases to the lower limit water level due to evaporation, water is supplied again to the upper limit water level. Thereafter, this operation is repeated, and steam is continuously supplied to the bathroom (not shown) from the steam port 12.

During the heating for steam generation, the scale pieces 21 newly form the inner surface 2.
It peels off from 0. The amount of peeling is the same as when the heat exchanger 3 is stopped, because the temperature change that the heat exchanger 3 undergoes during operation and stop is the same. Therefore, when the supply of steam is no longer required, the switch 16 is turned off to stop the operation, and the controller 18 that receives this signal stops the power supply to the heater 11, and the water supply valve 2
Then, the drain valve 15 is opened, and the water storage I9 is drained and water is supplied. In addition to the water flow, the scale pieces 21 separated from the inner surface 20 during operation are discharged from the drain port 13 by the drainage flow of the stored water 19. Thereafter, when the predetermined time set for discharging the scale pieces 21 has elapsed, the water supply valve 2 is closed and the operation is completed.

In this way, if the operation for discharging the exfoliated scale pieces 21 is divided into a total of two times, before and after the heating operation, the amount of discharge per time is reduced to one-half. Further, unlike the conventional example, a large amount of scale pieces 21 generated twice before and after heating are not discharged all at once in a short period of time when a drainage flow occurs, so that the drainage channel 14 is not clogged.

Furthermore, when the amount of steam supplied is large, the heating operation becomes long, and the number of scale pieces 21 peeled off from the inner surface 20 increases in proportion to the increase in the amount of scale components contained in the supplied water adhering to the inner surface 20. Therefore, the predetermined time for discharging the scale pieces 21 is set to a time that corresponds to the amount of peeling that occurs during the maximum time (about 15 minutes) used in the steam bath and allows sufficient discharge. However, in the conventional example, the time for discharging the scale pieces 21 is limited by the capacity of the water storage 19 of the heat exchanger 3. That is, by dividing the water storage capacity by the amount of water that can drain the scale pieces 21, the drainage time that the water storage 19 has can be determined. There is a permissible lower limit for the amount of water discharged, and in order to lengthen the time for water drainage, the capacity must be increased. However, the heat exchanger 3 is designed to have the best shape in consideration of heating efficiency, heating rate, etc. If the water storage capacity is increased, for example, in order to keep the heating rate the same, the amount of heating must be increased, and the capacity of the heater 11 must be increased. As described above, in the conventional example, the setting of the drainage time was limited due to economic reasons, but in this embodiment, there is no such limitation and the drain time can be set freely. Note that the amount of drainage per unit time related to the drainage force can also be freely set depending on the amount of water supply.

FIG. 2 shows a second embodiment, in which the water supply channel 22 is connected to the heat exchanger 2.
It is connected to the water supply port (cum-drainage port) 24 of No. 3, and a drainage channel 25 branches off from the middle. In addition, the switch is 26, the drain valve is 27, the water supply valve is 28, the water storage is 29, the electrode is 30, the inner surface is 31, the scale piece is 32, and the heater is 33.

Next, to explain the operation, first switch 2 to start operation.
6 is turned on, the drain valve 27 is closed, the water supply valve 28 is opened, and water starts to be supplied to the heat exchanger 23. When the stored water 29 reaches the lower limit water level of the electrode 30, the water supply valve 28 closes and the drain valve 27 opens, and the stored water 29 is drained from the water supply port 24. At this time, scale pieces 32 that were separated from the inner surface 31 during the stoppage
is discharged to the drainage channel 25 via the water supply port 24 by the drainage flow.

Next, when the set drainage time has elapsed, taking into account the time required for draining the stored water 29, the drain valve 27 closes and the water supply valve 28 closes.
opens and when the water storage 29 reaches the upper limit water level of the electrode 30, water supply stops. On the other hand, when the water storage 29 reaches the lower limit water level,
The heater 33 is energized to heat the stored water 29 and generate steam.

Next, when the supply of steam is no longer required, the switch 26 is turned off to stop energizing the heater 33, the water supply valve 28 is closed, and the drain valve 27 is opened. is discharged by the drainage stream.

In this way, as in the previous embodiment, the amount of scale pieces 32 peeled off from the inner surface 31 is discharged before heating while the heating operation is stopped, and the amount of scale pieces 32 peeled off during heating operation is discharged after heating. Then, equal amounts of scale pieces 32 are divided before and after heating, and the amount of each discharged amount is small, so the drainage channel 25 is not clogged with scale pieces 32, and compared to the conventional example, the drainage operation is improved. It is economical and only needs to be added before heating operation.

Note that, as in the first embodiment, the same effect can be obtained even if the drain channel 25 is connected to a drain port provided separately from the water supply port 24.

Further, in the first embodiment, even if the draining operation of the second embodiment is performed either before or after heating, the effects of the second embodiment can be obtained.

Effects of the Invention As is clear from the above explanation, the present invention discharges scale pieces exfoliated from the inner surface of a heat exchanger twice, before and after heating, and also adjusts the amount of discharged water and the time to match the amount of exfoliation. It is designed to be set and discharged effectively.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a first embodiment of the steam generator according to the present invention, FIG. 2 is a block diagram showing the second embodiment, and FIG. 3 is a block diagram showing a conventional steam generator. be. 1,22... Water supply waterway, 3.23... Heat exchanger 1. 25...Drainage channel, 15. Drainage outlet).

Claims (2)

[Claims] (1) A water supply channel with a water supply means, a drainage channel with a drain valve, a heat exchanger that connects the water supply channel and the drainage channel to heat stored water and generate steam, and before and after heating. A steam generator comprising a controller that controls the water supply channel and the drainage channel at both times to perform water supply and drainage. (2) A water supply port connected to a water supply channel having a water supply means, a drain port connected to a drainage channel having a drain valve, and a heat exchanger that heats stored water and generates steam by providing the water supply port and the drain port. A steam generator comprising: a controller that controls the water supply channel and the drainage channel during non-heating, and performs water supply and drainage in parallel for a predetermined period of time.