JPH09269101A - Steam generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a steam generator which is small-sized and susceptible of less failure. SOLUTION: An upper cover 3 and a lower cover 4 are mounted to a top and bottom of a cylindrical-shaped insulating casing 1. Provided in the casing 1 is an electrically conductive heating element 9 having therein a multiplicity of voids and adapted to generate heat by induction heating when an AC current passes through a coil 2 wound around an outer peripheral wall of the casing 1. Water supplied into the casing 1 through a feed water pipe 8 is heated by contact with the heating element 9 to make water vapor to be transferred outside the easing 1 through a delivery pipe 7. The heating element 9 is hollow at its core portion to allow a water level detecting electrode bar 5 to be inserted thereinto from the upper cover 3. With such arrangement, a highly reliable steam generator free of troubles such as plugging of a water pipe, disconnection of an electric heater and the like can be obtained which can provide water vapor efficiently with a compact configuration.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a steam generator for heating water to generate steam.

[0002]

2. Description of the Related Art FIG. 28 is a schematic configuration diagram of a conventional steam cleaner. Water is stored in the water tank 80, and after the impurities are removed by the water softener 81, the water is sent to the steam generator 84 by the suction force of the pump 82. A check valve 83 is provided in front of the steam generator 84 to prevent backflow of water. The steam generated by the steam generator 84 is jetted from the handpiece 86 via the electromagnetic valve 85. Further, in order to prevent the sudden ejection of water vapor, the water vapor escapes from the safety valve 88 via the pressure switch 87.

FIG. 29 is a block diagram of the steam generator 84. A water supply pipe 91 to which water is supplied below the steam cylinder 90.
However, in the upper part, a steam delivery pipe 9 reaching the handpiece 86 is provided.
2 are connected. Further, an electrode 93 for detecting the water level inside the steam cylinder 90 is inserted from above. A meandering water pipe 94 having a small diameter is connected between above and below the steam cylinder 90, and an electric heater 95 is closely attached to the water pipe 94. The water supplied into the steam cylinder 90 is heated in the water pipe 94 to become steam, which is further heated to a higher temperature while rising in the water pipe 94 and is sent to the outside of the steam cylinder 90 through the delivery pipe 92. When the amount of water in the steam cylinder 90 is reduced, the electrode 93 detects the lowering of the water level and the pump 82 is activated to operate the water supply pipe 91.
Is replenished with water.

[0004]

The conventional steam generator has the above-mentioned structure, and has a steam cylinder 90 for holding high-temperature water with a margin against a sudden load change and a water pipe arranged outside the steam cylinder 90. In addition, since a heat insulating material for keeping the temperature of the steam / water cylinder 90 is provided around the steam / water cylinder 90, the shape is large and it is difficult to reduce the size. Further, even if the water softener 81 is used, it is difficult to completely remove calcium carbonate and the like contained in water, so that scale (calcium carbonate crystals) is deposited on the inner wall of the water pipe 94. If the scale accumulates on the inner wall of the water pipe 94, the heat conduction will be deteriorated and the efficiency of heat exchange will be reduced. As the scale builds up, the water tube 94 may even become blocked. Furthermore, if heat conduction deteriorates,
When the same amount of heat is applied to water, the heater temperature rises, and the electric heater 95 is likely to break.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a small-sized steam generator with low running cost.

[0006]

Means for Solving the Problems and Embodiments of the Invention A steam generator made to solve the above problems comprises a) a cylindrical member made of an insulator, and an insulator or a conductor. A container composed of a lid member provided on the upper and lower end surfaces of the container, b) a coil wound around the outer peripheral wall of the cylindrical member, c) a power supply means for supplying an alternating current to the coil, and d) the above. A heating element which is a conductor housed inside the container; e) a water supply pipe for supplying water into the container; and f) water vapor generated when the water in the container comes into contact with the heating element. And a delivery pipe for carrying it out to the outside.

The insulating container is arranged in a vertically standing state, the water supply pipe is connected to the lower lid of the container, for example, to the lower lid, and the delivery pipe is connected to the water-absorption position above the container, for example, the upper lid. When an appropriate amount of water is sent from the water supply pipe into the container and an alternating current is passed through the coil, Joule heat is generated in the heating element, and the water contacting the heating element is heated. The generated water vapor rises in the upper space inside the container, and is heated to a higher temperature by coming into contact with the heating element during this time, and taken out of the container through the delivery pipe.

In the steam generator having the above construction, it is preferable that a hollow portion is formed in the core portion of the heating element, and an electrode rod for water level detection is inserted from the upper portion of the container into the hollow portion.

That is, since the heat generated in the heating element is biased to the outer peripheral side by the skin effect, the temperature rise on the central side is small. Therefore, if the central portion of the heating element is made hollow in advance and an electrode for water level detection is arranged here, the water located in this hollow does not boil violently, and the water level fluctuation is small and accurate water level detection can be performed.

Further, at the boundary between the hollow portion of the heating element and the conductor, a partition wall that does not allow the passage of fluid may be provided. Without this partition, water and steam move freely across the boundary between the hollow part and the conductor, so for example, steam generated in the void of the conductor escapes to the hollow part side and is not sufficiently heated. It may reach the delivery pipe as it is. However,
If the partition wall is provided, the water vapor generated in the void of the conductor is blocked by the partition wall and does not escape to the hollow portion side, but rises while surely passing through the void of the conductor. Therefore, sufficiently heated steam can be obtained in the delivery pipe. Further, since the temperature of the water located in the hollow portion is kept lower than the temperature of the water located on the conductor side, the fluctuation of the water surface becomes smaller and the accuracy of water level detection is improved.

Only one electrode rod for detecting the water level is provided, the conductive lower lid provided on the bottom surface of the container or the heating element itself is used as the other electrode, and the electrode portion at the tip of the electrode rod and the other electrode are provided. The water level can be detected by detecting the conduction between the two.

In the steam generator according to the present invention, it is convenient that at least one of the upper lid and the lower lid of the container is detachably provided and the water supply pipe or the delivery pipe is arranged on the cylindrical member side of the container. good. According to this, the upper lid or the lower lid can be removed and the heating element inside the container can be easily taken out without removing the water supply pipe or the delivery pipe. Therefore, even if the scale adheres to the heating element, the heating element can be easily washed and replaced. In addition, it is possible to quickly inspect the inside of the container when an abnormality occurs.

In this case, in order to easily take out the heating element, it is preferable that the detachable lid side portion of the heating element has a projection shape. Alternatively, the heating element may be fixed to a detachably provided lid, and the heating element may be pulled out of the container at the same time when the lid is removed.

Furthermore, in the steam generator according to the present invention, the outer periphery of the heating element is arranged at a substantially equal position from the inner peripheral wall surface of the container, and the heating element is gently fixed by a lid member so that the heating element can vibrate. Is also good. In order to loosely fix the heating element, for example, a concave portion may be formed in substantially the center of both upper and lower end surfaces of the heating element, and a convex portion may be formed in the lid member so as to be loosely fitted in the concave portion. Alternatively, a hollow hole that penetrates vertically may be formed substantially in the center of the heating element, and a protrusion that is loosely fitted in the hollow hole may be formed in either one of the upper and lower lid members. The upper and lower lid members may be formed with recesses that are loosely fitted to the outer circumference of the heating element.

According to this structure, the distance between the outer circumference of the heating element and the inner wall surface of the container is kept substantially the same at any position, and there is no deviation to one side. Therefore, the induced currents are generated almost uniformly on the same circle of the heating element, and the heat is also generated uniformly. Further, since the heating element is loosely fixed, vibration due to magnetostriction is not hindered, and the scale is less likely to adhere.

Further, in order to easily cause the vibration of the heating element, it is preferable to dispose the magnetostrictive vibrator in contact with the heating element. When an alternating current flows through the coil for heating, the magnetostrictive oscillator vibrates finely according to the frequency of the alternating current. Since this vibration is transmitted to the heating element and the heating element itself vibrates, it is possible to prevent the scale from adhering.

In the steam generator according to the present invention, heating can be performed while discharging water from a drain port provided at a predetermined position in the container. It is advisable to provide this drain port slightly below the lowest water level line in the container during normal use. According to this, high-temperature water having a temperature close to the boiling point is discharged from the drain port. Since water near the boiling point contains a large amount of calcium carbonate, which is a cause of scale, this configuration suppresses scale adhesion.

When it is not necessary to continuously generate steam, water is stored in the container, and after the water is reduced by evaporation, all the water in the container is drained and new water is supplied into the container. Also good. That is, if the concentration of calcium carbonate in the water in the container increases, the water is replaced.

If a drainage tank for temporarily storing the water drained from the container is provided and the water supply pipe is arranged so as to pass through the drainage tank, hot water can be supplied through the water supply pipe line. It can be used to warm the low temperature water that flows into the water, which allows efficient use of energy.

[0020]

As described above, according to the steam generator of the present invention, since the heating element by induction heating is heated by the direct contact of water and steam, a thin water pipe or the like is not required and the structure is simple. It can be miniaturized. Further, since the clogging of the water pipe due to the adhesion of scale and the failure due to the disconnection of the electric heater are eliminated, and the heating element itself can be inexpensive, it is possible to provide a device with low running cost.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the basic construction of an embodiment of a steam generator according to the present invention will be described with reference to FIGS. FIG. 1 is a perspective view (partially sectional view) showing the appearance and the inside of this steam generator,
2 is a vertical cross-sectional view of this steam generator, FIG. 3 is a perspective view showing an example of the shape of a heating element in this steam generator, FIG. 4 is a cross-sectional view of this heating element, and FIG. It is a figure which shows the structural example of the steam generation system used.

A coil 2 is wound around a substantially cylindrical case 1 made of an insulating material such as plastic or ceramic, and an upper lid 3 made of metal such as brass or ceramics is provided on the upper and lower surfaces of the case 1. The lid 4 is fixed with bolts and nuts, etc., with the sealing material sandwiched therebetween. Top lid 3
Has a structure in which an electrode holding portion 6 having a hole into which the electrode rod 5 is inserted is approximately fitted in its center, and a vapor delivery pipe 7 is connected by welding or fitting. On the other hand, a water supply pipe 8 is connected to the lower lid 4 by welding or fitting. Inside the case 1, a columnar heating element 9 which is a metal conductor and has a large number of suitable voids through which a fluid (liquid or gas) can pass, and whose core is hollow in the vertical direction is accommodated. Has been done. The electrode rod 5 is supported by the electrode holding portion 6 of the upper lid 3, and is inserted along the hollow portion of the heating element 9. This electrode rod 5 is composed of three electrodes. The electrode rod 5a that is inserted deepest (downward) is grounded, the electrode rod 5b in the middle position is for low water level detection, and the electrode rod 5c in the uppermost position is high. It is for water level detection.

In the steam generator having the above structure, the water supply pipe 8
The operation of the pump (not shown) connected to is controlled according to the conduction state of the three electrode rods 5a, 5b, 5c. That is, when the electrode rod 5a and the electrode rod 5b are not electrically connected to each other, the pump is operated and water is fed into the case 1 through the water supply pipe 8. When the water level in the case 1 rises to the position where the tip of the electrode rod 5c is submerged in water, electrical connection is established between the electrode rod 5a and the electrode rod 5c. At this time, the pump operation is stopped and the water supply is stopped. As will be described later, when the water level in the case 1 drops due to water evaporation, the tip of the electrode rod 5b is exposed in the air. Therefore, the electrode rod 5a and the electrode rod 5b are switched from the conductive state to the non-conductive state, and the pump is operated again. As a result of such control, the water level in the case 1 is maintained substantially between the electrode rods 5b and 5c.

When an alternating current flows through the coil 2, a magnetic flux that links the heating element 9 in the vertical direction is generated. Due to this magnetic flux, an eddy current is generated in the heating element 9 and Joule heat is generated. Due to this heat, the water stored in the case 1 is directly heated. The water vapor rising from the water surface in the case 1 is further heated by coming into contact with the hot heating element 9,
High-temperature steam (so-called dry steam that does not contain water drops) is sent to the outside through the delivery pipe 7. Therefore, the delivery pipe 7
A sufficiently heated high temperature steam is obtained from.

As a material of the heating element 9, a conductive and ferromagnetic material is preferable. Also, the water passage is in the height direction,
It is necessary to have an appropriate void inside so as to secure both in the radial direction, and to secure a path through which a current flows in the circumferential direction.

As the heating element 9, for example, as shown in FIG.
It is preferable to have a structure in which the wire mesh 10 is wound with a hollow at the center. In order to reliably secure a path along which the current flows in the circumferential direction, as shown in FIG.
Brazing material 1 such as soldering place (1 place is acceptable)
It is advisable to sandwich 1 and to weld the adjacent wire nets 10 later. According to this, not only the current path is secured, but also the structure of the heating element 9 is strengthened and is less likely to be deformed. Such a heating element 9 is not only easy to manufacture, but also by appropriately selecting the aperture ratio and the winding density of the wire mesh, the size of the voids for water passage can be easily adjusted to achieve good heat exchange. Can be realized.

In the steam generating system of FIG. 5 which uses the steam generator having the above-mentioned structure, a water supply side temperature sensor 15, a flow rate sensor 16, and a water supply valve 17 are arranged in a water supply pipe 8 connected to a water tap 18. . Further, a delivery side temperature sensor 19 is arranged in the delivery pipe 7. Each detection signal of the water supply side temperature sensor 15, the flow rate sensor 16, and the delivery side temperature sensor 19 is input to the control unit 14, and an operation signal is also input from the operation unit 13. A current is supplied to the coil 2 from the inverter 12, and the inverter 12 is controlled by the control unit 14.

When the desired steam generation amount, steam temperature, etc. are set in the operating section 13, the control section 14 opens the water supply valve 17 whose flow rate is adjustable to fill the case 1 with water, and the inverter 12 turns on. Drive to start supplying current to the coil. The water temperature sensor 15 monitors the water temperature, the flow sensor 16 monitors the water flow rate, the water level detection unit 20 monitors the water level in the case 1, and the delivery temperature sensor 19 monitors the steam temperature. The current supplied to the coil 2 and the amount of water supply are adjusted so that the desired steam temperature, the amount of steam generated, and the desired amount of steam are generated. The water in the case 1 is completely discharged by connecting a drain pipe having a drain valve to the water pipe 8 between the water temperature sensor 15 and the case, and opening the drain valve as necessary. It is more preferable that the configuration is made possible.

Next, a modified example of the steam generator having the basic structure of FIG. 2 will be described. 6 to 8 show a partition wall 2 that blocks passage of water or water vapor at the boundary between the hollow portion of the heating element 9 and the heating portion.
1 is an example in which 1 is provided.

FIG. 6 shows an example in which a cylindrical partition wall 21 is provided on the entire surface of the heating element 9 from the upper end to the lower end along the hollow portion. Water sent from the water supply pipe 8 into the case 1 is divided into an outer peripheral portion where the heating element 9 exists and a central portion where the electrode rod 5 exists. In the central portion surrounded by the partition wall 21, since the water does not directly contact the heating element 9, the temperature of the water does not become high enough to reach the boiling point. For this reason, the water surface does not foam and is kept almost horizontal. As a result, the water level can be accurately detected by the electrode rod 5. Further, the water vapor generated in the voids of the heating element 9 is blocked by the partition wall 21 and does not diffuse into the hollow portion. That is, the water vapor rises while passing through the voids of the heating element 9 as shown by the broken line arrow in FIG. Therefore, it also has an advantage that high temperature steam is surely generated.

FIG. 7 shows an example in which a cylindrical partition wall 21 is provided along the hollow portion from the lower end of the heating element 9 to a predetermined height above the water surface. That is, when only the purpose is to stabilize the water surface for accurate water level detection as described above, such a structure of the partition wall 21 provides a sufficient effect.

FIG. 8 shows an example in which a partition wall 21 similar to the example of FIG. 5 is provided and the coil 2 is not wound around the upper side surface of the case 1. In the case of the embodiment of FIG. 5, the heating element 9
The temperature distribution when the coil is heated by the coil 2 is substantially uniform in the height direction, but in the radial direction, the temperature becomes higher on the outer peripheral side (the side closer to the inner wall of the case 1) due to the skin effect. Therefore, even if the partition wall 21 is provided up to the upper end of the heating element 9, the heating state is different between the steam passing through the outer circumferential side of the heating element 9 and the steam passing through the inner circumferential side near the partition wall 21.
Therefore, as shown in FIG. 8, by providing a non-heated portion on the upper part of the heating element 9, it is possible to promote heat exchange between the steams and diffusive mixing, and improve the uniformity of the steams sent out from the delivery pipe 7.

Next, embodiments of steam generators having different water level detection methods will be described with reference to FIGS. FIG. 9 is a vertical cross-sectional view of this steam generator, FIG. 10 is a configuration diagram of the water level detection unit, and FIG. 11 is a waveform diagram for explaining the operation of the water level detection unit.

Since the water level in the case 1 determines the proportion of the heating element 9 that contributes to both liquid heating and gas heating, it is desirable to minimize the water level fluctuation in order to obtain stable steam. For this reason, in the method of adjusting the water level by using the three electrode rods 5a, 5b, 5c as shown in FIG. 2, it is necessary to narrow the gap in the height direction between the tips of the electrode rods 5a and 5b. Becomes However, the electrode rod 5
If the distance between the tips of a and 5b is too narrow, when the water surface undulates due to boiling, a state in which the tips of the electrode rods 5a and 5b are both separated from the water surface and a state in which the tips of the electrode rods 5a and 5b are both immersed in water Occur alternately. As a result, the pump frequently turns on and off, causing a failure. Also, three electrode rods 5
It is troublesome to install a, 5b and 5c and adjust the height.

In the embodiment shown in FIG. 9, only one electrode rod 5 is installed and the ground wire is connected to the lower lid 4. Of course, in this case,
The lower lid 4 is made of a conductive material. In addition, a ground wire is drawn into the case 1 to connect to the heating element 9, or the lower lid 4 and the heating element 9 are electrically connected to each other so that the heating element 9 itself is grounded. Is also good.
When the water level changes across the tip position of one electrode rod 5 installed in this way, the water surface wavy fine as shown in FIG. 11 (a). Therefore, as shown in FIG. 11B, the conductive state between the electrode rod 5 and the ground point is frequently repeated between conductive (signal level “1”) and non-conductive (signal level “0”). Be done.

The result of the continuity detection is input to the terminal 31 of the water level detector 20. This signal is input to the non-inverting input terminal A and the inverting input terminal B of the monostable multivibrator 35 via the gate 33 and the gate 34, respectively. The monostable multivibrator 35 is a retriggerable multivibrator having a time constant τ. Therefore, FIG.
When a pulse signal (conduction detection result) is input to the terminal 31 when the normal output of the flip-flop 37 is at "0" level as shown in (c), the pulse signal is applied to the gate 3
3 to trigger the monostable multivibrator 35. Since the monostable multivibrator 35 is a retriggerable type, its inverted output falls in synchronization with the first rising edge of the series of pulse signals and rises at a time constant τ delayed from the last rising edge of the series of pulse signals. (See FIG. 11 (d)).

A periodic clock signal having a sufficiently high frequency is supplied to the terminal 32, and the monostable multivibrator 3 is supplied.
This clock signal passes through the gate 36 and is applied to the clock terminal CLK of the flip-flop 37 only when the inverted output of 5 is at "1" level (see FIG. 11 (e)).
In the flip-flop 37, the signal supplied to the data terminal D, that is, the conduction detection result is read in synchronization with the rising edge of the signal input to the clock terminal CLK, so the normal output is as shown in FIG. It rises when the first pulse signal is input to the clock terminal CLK. After the non-inverted output of the flip-flop 37 becomes "1" level, the pulse signal of the conduction detection result is the gate 34
To the inverting input B of the monostable multivibrator 35. As a result, even if the continuity detection result is repeatedly turned on and off as shown in FIG. 11B, a water level detection signal without chattering can be obtained as shown in FIG. 11C.

By controlling the operation of the pump and the opening / closing of the water supply valve according to such a water level detection signal, the water level in the case 1 is maintained near a predetermined water level set by the height of the electrode rod 5. . Moreover, even if the water surface is wavy, it is possible to prevent the pump and the water supply valve from frequently turning on and off at short intervals.

Next, another embodiment of the steam generator in which the structures of the delivery pipe 7 and the water supply pipe 8 are changed will be described. FIG. 12 is a vertical cross-sectional view showing a configuration of a steam generator for obtaining steam in different states. In this embodiment, the upper lid 3 has the first and second
The two delivery pipes 7a and 7b are connected. Similar to the delivery pipe 7 of FIG. 2, the first delivery pipe 7a is provided with an outlet in the upper space of the case 1, while the second delivery pipe 7b extends into the case 1 and its outlet. Is provided near the water surface in the hollow portion of the heating element 9. Therefore, the second delivery pipe 7b
The water vapor sent through is low-temperature steam (so-called wet steam) that has just risen from the water surface and that contains many water droplets. Such a steam generator is configured so that steam is selectively ejected from the first delivery pipe 7a and the second delivery pipe 7b, and low temperature steam and high temperature steam are selected as required to obtain a handpiece. It can be applied to a steam washer that can be discharged from

FIG. 13 is a vertical cross-sectional view showing the structure of a steam generator which quickly generates steam after the apparatus is started. In this embodiment, the water supply pipe 8 is also provided on the upper lid 3 and extends inside the case 1, and the water supply port is provided directly above the heating element 9 such as a plurality of branches (not necessarily branched). . In such a steam generator, water is supplied to case 1
Before pouring water into the inside, the coil 2 is energized to heat the heating element 9, and water supply is started with the heating element 9 heated. The water poured from the water supply pipe 8 comes into contact with the hot heating element 9 to become steam in a moment, and is sent to the outside of the case 1 through the delivery pipe 7. That is, in the embodiment of FIG. 2, the water accumulated in the case 1 is gradually heated to a high temperature and then steam is gradually obtained. However, according to the embodiment of FIG. 13, steam can be quickly obtained. it can.

In the steam generator shown in FIG. 14, the water supply pipe 8 is connected to the upper lid 3 as in the example of FIG.
Further extends into the case 1, and the water supply port is provided near the inner wall of the lower lid 4. In this case, water vapor cannot be generated as quickly as in the embodiment of FIG. 13, but similarly, since the lower lid 4 does not have piping or the like, mounting freedom such as installation is reduced compared to the embodiment of FIG. 2 or the like. The degree increases.

In the steam generator having the above structure, the scale adheres to the heating element 9 when used for a long time. In the case of the steam generator according to the present invention, even if the scale adheres to the heating element 9, the state does not become unusable, but the flow path resistance increases and it is difficult to perform average heating. As a result, the efficiency of heat exchange deteriorates. Therefore, in order to perform efficient heating, it is necessary to take measures against scale adhesion.

First, an embodiment of a steam generator having a structure in which the heating element 9 is easily taken out from the case 1 in order to facilitate cleaning or replacement of the heating element 9 will be described with reference to FIGS. 15 and 16. FIG. 15 is a perspective view showing the appearance of the steam generator, and FIG. 16 is a perspective view showing a state in which a heating element is taken out from the steam generator.

The structural feature of this embodiment is that the vapor delivery pipe 7 is connected not to the upper lid 3 but to the upper side surface of the case 1. Thereby, the upper lid 3 can be easily removed without any obstacle. Further, as the heating element 9, a structure in which a plurality of donut-shaped metal plates having a large number of holes are laminated is used, and the whole metal plates are bundled in a substantially central position so that they can be pulled out upward. A support rod 22 having a pressing plate at the lowermost end is penetrated. Therefore, after removing the upper lid 3, the upper end of the support rod 22 can be picked up and pulled up, and the heating element 9 can be easily taken out. After that, the heating element 9
Each metal plate may be removed from the support rod 22 and cleaned, or a young metal plate may be replaced with a new one.

FIG. 17 is a perspective view of a steam generator showing a modification of FIG. 16, in which the upper lid 3 and the heating element 9 are integrated by fixing the upper end of the support rod 22 to the inner wall of the upper lid 3. Is. According to this, the heating element 9 can be taken out at the same time when the upper lid 3 is removed.

FIG. 18 is a perspective view of a steam generator in which the lower lid 4 can also be easily removed. The water supply pipe 8 is located on the lower side of the case 1 on the side facing the connecting portion of the delivery pipe 7. Connected to. According to this, the upper lid 3,
Both the lower lid 4 can be easily removed.

The upper lid 3 as in the example of FIGS. 15 to 18 described above.
Or, by adopting a structure in which the lower lid 4 can be easily removed,
For example, when an abnormality such as no steam coming out of the delivery pipe 7,
There is also an advantage that the inside of the case 1 can be easily inspected.

The support bar 22 as shown in FIG.
May have a structure that also serves as the partition wall 21 described in FIG. That is, a part of the upper end of the partition wall 21 is attached to the heating element 9
The structure may be such that it extends above the upper end surface and is easily grasped by a finger or a tool. Further, such a support rod 22 does not necessarily have to be in the center of the heating element 9, and for example, a resin-based support member for fixing a plurality of metal plates by sandwiching them one by one around the heating element 9 may be provided. You can

Next, regarding the adhesion of the scale to the heating element 9, an embodiment of a steam generator having a structure in which the scale does not easily adhere will be described.

Since the heating element 9 is a magnetic material, vibration due to magnetostriction occurs depending on the frequency of the high frequency current flowing through the coil 2. Therefore, it is possible to prevent the scale from adhering to the heating element 9 by adopting a structure in which the vibration is not suppressed inside the case 1, the heating element 9, the upper lid 3, the lower lid 4, and the like.

In order for the heating element 9 to vibrate in the case 1, it is necessary to make the outer diameter of the heating element 9 smaller than the inner diameter of the case 1. However, such a heating element 9
If only is stored in the case 1, the heating element 9 is biased or tilted in the case 1, and a portion close to the coil 2 and a portion far from the coil 2 are generated. Since the magnetic field generated by the current flowing through the coil 2 is stronger as the coil 2 is closer to the coil 2, if the central axes of the heating element 9 and the case 1 are largely deviated from each other, the heat generation on the same circumference of the heating element 9 becomes uneven. . Then, at a location where heat is concentrated, scale is likely to adhere and rust is also likely to occur.

19 to 21 show an embodiment of a steam generator which does not suppress the vibration of the heating element 9 and has a desirable structure for positioning the central axis of the heating element 9 near the central axis of the case 1. FIG.

In the embodiment shown in FIG. 19, a cylindrical heating element 9 is used.
The upper lid 3 and the lower lid 4 are formed by forming a concave portion in the substantially center of the upper and lower end surfaces of the upper lid 3 and the lower lid 4.
The convex portions 3a, 4a corresponding to the concave portions are formed on the inner wall surface of the. By making the outer diameters of the convex portions 3 a and 4 a slightly smaller than the inner diameter of the concave portion of the heating element 9, the heating element 9 is loosely fitted to the upper lid 3 and the lower lid 4. Therefore, the heating element 9
It freely vibrates within the margin between the concave portion and the convex portions 3a, 4a. In this example, the recess formed in the heating element 9 may be a hole penetrating in the vertical direction.

When a hole (hollow portion) penetrating in the up-down direction is formed substantially in the center of the heating element 9, as shown in the embodiment of FIG. 20, only one of the upper lid 3 and the lower lid 4 is provided. Alternatively, a rod-shaped protrusion 4b corresponding to the hollow portion may be formed, and the heating element 9 may be loosely fitted into the protrusion 4b.

Further, in the embodiment shown in FIG. 21, heating element receivers 3c and 4c having convex portions corresponding to the outer circumference of the heating element 9 are formed on the inner wall surfaces of the upper lid 3 and the lower lid 4. With such a structure, the same effect as that of the example of FIGS. 19 and 20 can be obtained.

19 and 21, only the upper and lower portions of the heating element 9 are supported, so that the heating element 9
However, it is not preferable to simply stack disc-shaped metal plates having a large number of holes. Therefore, in such a heat generating element, it is necessary to prevent lateral displacement of the metal plates by, for example, penetrating the stacked metal plates in the vertical direction. That is, the support rod 22 and the like shown in the embodiment of FIG. 16 can be used for this purpose.

As described above, the heating element 9 itself vibrates at high frequency during heating, but since the vibration is not necessarily large, the effect of preventing scale adhesion is not sufficient.
Therefore, in the following embodiment, scale adhesion is further prevented by positively increasing the vibration of the heating element 9 during heating.

Heating element 9 of the steam generator according to this embodiment
When the magnetostrictive vibrator is provided in close contact with the metal body that is the heating element, the vibrator vibrates according to the frequency of the high frequency current flowing in the coil 2. As the magnetostrictive oscillator, a generally known ferrite oscillator or the like can be used, and it is preferable to use a permanent magnet together with the magnetostrictive oscillator in order to bias the DC magnetic field to the high frequency magnetic field generated by the high frequency current flowing in the coil 2.

As the heating element 9, a magnetostrictive oscillator 41 and a permanent magnet 42 are attached to each other so as to sandwich the heating element 9 from above and below (see FIG. 22). What is sandwiched between the heating elements 9 from above and below (see FIG. 23), and one in which the magnetostrictive oscillator 41 and the permanent magnet 42 are respectively sandwiched between the heating elements 9 (FIG. 2).
4)) and various other structures. Further, the metal body of the heating element 9 and the magnetostrictive oscillator 41 and the permanent magnet 42 may be fixed to each other by using an adhesive or the like, or may simply be arranged in close contact with each other.

In any structure, when a high-frequency current flows through the coil 2, the magnetostrictive vibrator 41 vibrates, and this vibration also vibrates the heating element 9 itself. This vibration is due to the magnetostrictive oscillator 4
As compared to the case where 1 is not used, the scale adhesion is greatly reduced because it is considerably larger.

Now, the construction and operation of a steam generator using another method for preventing scale adhesion will be described with reference to FIGS. 25 to 27. FIG. 25 is a diagram showing the structure of the steam generator according to this embodiment. The water supply pipe 8 provided with a water supply valve 56 for supplying water into the case 1 is spirally wound and arranged in the drain tank 51. The drainage tank 51 has a case drainage valve 58 for introducing water in the case 1.
The case drainage pipe 57 provided with is connected, and the drainage pipe 54 provided with the drainage valve 55 for discharging the water in the drainage tank 51 is connected. Further, the drainage tank 51 is provided with a drainage tank water level detector 52 for detecting the water level and a drainage tank water temperature detector 53 for detecting the water temperature. The opening / closing operations of the drain valve 55, the water supply valve 56, and the case drain valve 58 are controlled by a controller (not shown).

The case drain pipe 57 is connected on the side surface of the case 1 slightly below the surface of the water stored in the case 1. That is, the concentration of calcium carbonate contained in the water increases near the water surface where the water in the case 1 evaporates violently, and in particular, it tends to adhere to the heating element 9 in the vicinity thereof. Therefore, by gradually discharging high-temperature water having an increased calcium carbonate concentration, scale adhesion is prevented.

The operation of the continuous vapor generation will be described below with reference to the control flowchart of FIG. The control unit opens the water supply valve 56, which starts water supply into the case 1 (step S11). The water level in the case 1 is detected by the water level detection unit 20 (step S12), and when the predetermined water level is reached (step S13), the water supply valve 56 is closed and the water supply is stopped (step S14). Then,
The case drain valve 58 is opened so that the amount of water corresponding to a predetermined initial value of the drainage amount is discharged from the case 1 through the drain pipe 57 (step S15). Further, the water supply valve 56 is opened so that a predetermined amount of water is supplied (step S16).

Next, the control unit drives the inverter 12, and the current flows through the coil 2 to start heating the water in the case 1 (step S17). As the heating progresses, the water in the case 1 evaporates and is sent to the outside of the case 1 through the delivery pipe 7.
Therefore, the water level drop in the case 1 is the sum of the drainage through the drainage pipe 57 and the evaporation. The water level in the case 1 is always detected by the water level detection unit 20 (step S
18) When the water level becomes equal to or higher than a predetermined standard water level (step S19), the case drain valve 5 is used to increase the drainage amount.
The opening amount of 8 is increased (step S20). On the contrary, when the water level becomes lower than the specified water level, the opening amount of the case drain valve 58 is reduced to reduce the drainage amount (step S2).
1). That is, the water level in the case 1 is kept substantially constant by controlling the opening / closing of the case drain valve 58.

On the other hand, in the drain tank 51, the drain valve 55 is first closed (step S22), and the water sent from the case 1 through the drain pipe 57 is stored (step S2).
3). The water level in the drainage tank 51 is detected by the drainage tank water level detection unit 52 (step S24), and when it does not reach the predetermined water level, the process proceeds from step S25 to S27, and the predetermined water temperature is detected by the detection value of the drainage water temperature detection unit 53. It is determined whether or not the above (step S28). When the predetermined water temperature is not reached, the drain valve 55 is opened and the drain pipe 54
Through the drainage tank 51 through the
29). The water level is detected again (step S30), and when it does not reach the predetermined water level or lower, the drain valve 55 is closed (step S32), and the process returns to step S24.

If the water temperature is equal to or higher than the predetermined water temperature in step S28, the process returns to step S24. That is, according to this flow chart, normally, the drainage tank 51 is always filled with water near the predetermined water temperature to a predetermined water level. The hot water filled in the drain tank 51 indirectly warms the water passing through the water supply pipe 8. Therefore, it is possible not only to prevent the scale from adhering, but also to preheat the supply water by utilizing the exhaust heat to improve the efficiency of steam generation.

Further, in the steam generator in which steam is not generated continuously as in the above-described embodiment, but there is an intermittent steam generation, that is, there is a period in which steam is not generated at every predetermined time, the drain pipe 57 may be connected to the lower side surface of the case 1 or the lower lid 4.

The driving operation in this case will be described with reference to the control flowchart of FIG. First, the control unit controls the water supply valve 5
6 is opened, whereby water supply into the case 1 is started (step S41). The water level in case 1 is the water level detection unit 2
0 is detected (step S42), and when the predetermined water level is reached (step S43), the water supply valve 56 is closed and the water supply is stopped (step S44).

Next, the control unit drives the inverter 12, current flows through the coil 2, and heating of the water in the case 1 is started (step S45). As the heating progresses, the water in the case 1 evaporates and is sent to the outside of the case 1 through the delivery pipe 7, and the water level in the case 1 gradually decreases. The water level is always detected by the water level detection unit 20 (step S46), and when the water level falls below the specified water level (step S47), the supply of current to the coil 2 is cut off and heating is stopped (step S).
48). Then, the case drain valve 58 is opened (step S49), and the entire amount of water in the case 1 is drained (step S50). After that, the case drain valve 58 is closed (step S51), the step returns to S41, and the case 1 again.
Water is supplied to the inside.

On the other hand, in the drain tank 51, the drain valve 55
Is closed (step S52), and the drain pipe 5 is removed from the case 1.
The high temperature water drained through 7 is stored (step S53). The water temperature in the drainage tank 51 is the drainage water temperature detection unit 53.
Is detected (step S54), and if the predetermined water temperature has not been reached, the drain valve 55 is opened (step S5).
6). The water level in the drainage tank 51 is detected by the drainage water level detection unit 52 (step S57). If the water level is below a predetermined level (step S58), the drainage valve 55 is closed (step S59). If the water temperature is equal to or higher than the predetermined water temperature in step S55, the drain valve 55 remains closed,
Water continues to accumulate.

That is, according to this flowchart,
When water vapor is generated and the calcium carbonate concentration in the water in case 1 is increased, the entire amount of water in case 1 is replaced.
The water drained from the case 1 is used to preheat the supply water as in the previous embodiment. Therefore, efficient steam generation can be performed.

While the embodiments of the present invention have been illustrated and described above, it will be apparent to those skilled in the art that various other variations and modifications can be made without departing from the spirit and scope of the present invention. Accordingly, such variations and modifications are encompassed within the scope of the appended claims and are within the scope of the invention.

[Brief description of drawings]

FIG. 1 is a perspective view showing a configuration of an embodiment of a steam generator according to the present invention.

FIG. 2 is a vertical cross-sectional view showing the configuration of an embodiment of a steam generator according to the present invention.

FIG. 3 is a perspective view showing an example of a heating element in the steam generator according to the present invention.

4 is a cross-sectional view of the heating element of FIG.

FIG. 5 is a configuration diagram of an embodiment of a steam generation system using a steam generator according to the present invention.

FIG. 6 is a vertical cross-sectional view showing the configuration of another embodiment of the steam generator according to the present invention.

FIG. 7 is a vertical cross-sectional view showing the configuration of another embodiment of the steam generator according to the present invention.

FIG. 8 is a vertical cross-sectional view showing the configuration of another embodiment of the steam generator according to the present invention.

FIG. 9 is a vertical cross-sectional view showing the configuration of another embodiment of the electrode rod in the steam generator according to the present invention.

FIG. 10 is a circuit configuration diagram of a water level detection unit.

11 is a waveform chart showing the operation of the circuit of FIG.

FIG. 12 is a vertical cross-sectional view showing the configuration of another embodiment of the steam generator according to the present invention.

FIG. 13 is a vertical cross-sectional view showing the configuration of another embodiment of the steam generator according to the present invention.

FIG. 14 is a vertical cross-sectional view showing the configuration of another embodiment of the steam generator according to the present invention.

FIG. 15 is a perspective view showing the configuration of another embodiment of the steam generator according to the present invention.

16 is a perspective view showing a state in which a heating element is taken out in the embodiment of FIG.

FIG. 17 is a perspective view showing a modified example of FIG.

FIG. 18 is a perspective view showing the configuration of another embodiment of the steam generator according to the present invention.

FIG. 19 is a vertical cross-sectional view showing the configuration of another embodiment of the steam generator according to the present invention.

FIG. 20 is a vertical cross-sectional view showing the configuration of another embodiment of the steam generator according to the present invention.

FIG. 21 is a vertical cross-sectional view showing the configuration of another embodiment of the steam generator according to the present invention.

FIG. 22 is a vertical cross-sectional view showing the configuration of another embodiment of the steam generator according to the present invention.

FIG. 23 is a vertical cross-sectional view showing the configuration of another embodiment of the steam generator according to the present invention.

FIG. 24 is a vertical cross-sectional view showing the configuration of another embodiment of the steam generator according to the present invention.

FIG. 25 is a configuration diagram of another embodiment of the steam generator according to the present invention.

FIG. 26 is a flowchart for explaining the operation of the embodiment of FIG.

FIG. 27 is a flowchart for explaining the operation of another embodiment.

FIG. 28 is a schematic configuration diagram of a conventional steam cleaner.

FIG. 29 is a configuration diagram of a conventional steam generator.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Case 2 ... Coil 3 ... Upper lid 3a ... Convex part 4 ... Lower lid 4a ... Protrusion 5 ... Electrode rod 6 ... Electrode holding part 7 ... Delivery pipe 8 ... Water supply pipe 9 ... Heating element 12 ... Inverter 21 ... Partition wall 22 ... Support Rod 41 ... Magnetostrictive oscillator 51 ... Drainage tank

Claims (15)

[Claims] 1. A container composed of a) a cylindrical member made of an insulator and a lid member provided on the upper and lower end surfaces of the container made of an insulator or a conductor; and b) wound on an outer peripheral wall of the cylindrical member. A wound coil, c) a power supply means for supplying an alternating current to the coil, d) a heating element which is a conductor housed in the container, and e) a water supply pipe for supplying water into the container. And f) a delivery pipe for carrying out water vapor generated when the water in the container comes into contact with the heating element to the outside of the container, a steam generator. 2. The steam generator according to claim 1, wherein a hollow portion is formed in a core portion of the heating element, and an electrode rod for detecting a water level is inserted into the hollow portion from an upper portion of the container. . 3. The steam generator according to claim 2, wherein a partition wall that does not allow passage of a fluid is provided at the boundary between the hollow portion of the heating element and the conductor. 4. The number of the electrode rods is one, and the conductive lid or the heating element provided on the bottom surface of the container is used as the other electrode, and the electrode portion at the tip of the electrode rod and the other electrode are connected. The steam generator according to claim 2, wherein the water level is detected by detecting the continuity between the steam generators. 5. The container according to claim 1, wherein at least one of an upper lid and a lower lid of the container is detachably provided, and the water supply pipe or the delivery pipe is arranged on a cylindrical member side of the container. Steam generator. 6. The steam generator according to claim 5, wherein, in the heating element, the detachably provided lid side portion has a projection shape for drawing out the heating element. 7. The steam generator according to claim 5, wherein the heating element is fixed to the detachably provided lid. 8. The lid is gently fixed by the lid member so that the outer circumference of the heating element is substantially even from the inner wall surface of the container and the heating element can vibrate. Steam generator according to. 9. The method according to claim 8, wherein recesses are formed in substantially the center of both upper and lower end surfaces of the heating element, and a projection is formed on the lid member so as to be loosely fitted in the recess. Steam generator. 10. The heating element is formed with a hollow hole that penetrates up and down substantially in the center thereof, and a protrusion that is loosely inserted into the hollow hole is formed in one of the lid members. Item 9. The steam generator according to Item 8. 11. The steam generator according to claim 8, wherein the upper and lower lid members are formed with recesses that are loosely fitted to the outer circumference of the heating element. 12. The steam generator according to claim 1, wherein a magnetostrictive oscillator is arranged in contact with a conductor of the heating element. 13. The steam generator according to claim 1, wherein heating is performed while discharging water from a drain port provided at a predetermined position in the container. 14. The container according to claim 1, wherein water is stored in the container, and after the water is reduced by evaporation, all the water in the container is drained and new water is supplied into the container. Steam generator. 15. The drainage tank for temporarily storing water drained from the container is provided, and the water supply pipe is arranged so as to pass through the inside of the drainage tank. The steam generator described.