JPH09122635A - Apparatus for removing impurity in water - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable the treatment of a large volume of water by a method in which impurities can hardly stick to a heating surface, and maintenance is easy. SOLUTION: An apparatus for removing impurities in water to obtain pure water by evaporating water containing impurities such as ions is equipped with a tank 5 to which water is supplied and which discharges steam and a heating part 1 which receives water in the tank 5, converts the water into a mixture of steam and hot water, and returns the mixture to the tank 5. The heating part 1 is equipped with a pipe of a nonmagnetic material, a coil wound onto the pipe 11, and a heating body 12 which is received in the pipe 11 and is heated by electromagnetic induction generated by the coil 13. The tank 5 is equipped with a discharge part 3 for discharging water in which impurities are concentrated, and the impurities are prevented from sticking to the heating body 12 heated by electromagnetic induction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water impurity removing device for removing impurities such as ions dissolved in water, and more particularly to a water impurity removing device using an electromagnetic induction heating device.

[0002]

2. Description of the Related Art Water is always used when operating a boiler or a pure water producing apparatus. However, ordinary water (for example, industrial water) contains impurities such as ions. Therefore, in order to remove impurities such as ions dissolved in the water supplied to the boiler or pure water production equipment, an impurity removal device that uses an ion-exchange resin and an impurity removal device that evaporates water to obtain vapor from which impurities have been removed And the device is used. The steam from the device for evaporating water is used as water as it is or after being condensed by a heat exchanger as water.

[0003]

However, in an apparatus using an ion exchange resin, it is necessary to frequently activate or replace the resin in order to maintain the ion exchange resin. Further, there is a drawback that the solid solution which is not ionized cannot be removed.
On the other hand, although a device that evaporates water can remove a solid solution that is not ionized, impurities may stick to the heating surface, resulting in a decrease in thermal efficiency and sometimes damage. Therefore, it is necessary to clean the device frequently. Therefore, there is a problem in that maintenance requires labor. Further, when treating a large amount of water, there is also a problem that the installation area of the boiler, evaporator, condenser, etc. becomes large.

[0004] Therefore, an object of the present invention is to provide a compact water impurity removing device in which impurities are not easily fixed to the heating surface, maintenance is easy, and a large volume of water can be treated.

[0005]

In order to solve the above-mentioned problems, the invention according to claim 1 of the present invention is to remove the impurities of water to obtain pure water by evaporating water containing impurities such as ions. An apparatus comprising (a) a tank to which water is supplied and which discharges steam, and (b) a heating section which receives the water in this tank and returns it to the tank in a gas-liquid state in which steam and hot water are mixed. The heating unit includes a pipe made of a non-magnetic material, a coil wound around the pipe, and a heating element housed in the pipe and heated by electromagnetic induction by the coil, C) The tank is provided with a discharge part for discharging water in which impurities are concentrated.

[0006] As the heating element, one having a large heat transfer area, such as a laminated body, in which the fluid is regularly dispersed, diffused, diffused, or volatilized, is used.
The heat exchange performance is extremely high and the electromagnetic induction heating device can be installed in the middle of the piping. On the other hand, the impurities that try to adhere to the heating element are carried to the tank together with hot water, and the impurities are concentrated in the water tank. This prevents impurities from sticking to the heating surface.

According to a second aspect of the present invention, in addition to the first aspect of the invention, the amount of water heated per square centimeter of heat transfer area of the heating element is 0.4 cubic centimeters or less. It is characterized by being. Since the thickness of water in contact with the heating element is 0.4 cm or less,
Since the heat exchanging property with the heating element is extremely high and the temperature difference between the heating element and water becomes small, the precipitation of impurities on the heating surface is prevented.

According to a third aspect of the present invention, in addition to the first or second aspect of the present invention, a sensor for detecting the concentration of water impurities is attached to the tank, and based on the output of this sensor, the sensor from the tank is detected. It is characterized by controlling the drainage of water.

According to a fourth aspect of the invention, in addition to the first, second or third aspect of the invention, a liquid level gauge for detecting the water level is attached to the tank, and based on the output of the liquid level gauge. It is characterized in that the amount of water received in the tank is controlled.

In addition to the invention according to any one of claims 1 to 4, the invention described in claim 5 is characterized in that the water received from the tank to the heating section is generated by the rising force of gas-liquid in the heating section. It is characterized by circulation.

In addition to the invention according to claim 1, the invention according to claim 6 is provided with a heat exchanger for exchanging heat between the steam discharged from the tank and the water supplied to the tank. It is a feature. This not only supplies water from which impurities have been removed, but also condenses the steam into water and recovers the latent heat of the steam with water, thereby increasing the overall thermal efficiency.

[0012]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a device configuration diagram of a water impurity removing apparatus of the present invention.

In FIG. 1, reference numeral 1 is a heating unit, that is, an electromagnetic induction heating apparatus main body. 2 is a supply part, 3 is a discharge part, and 5 is a tank. The pipeline is a first line 41 that supplies the makeup water of the raw water from the outside to the tank 5 via the supply unit 2.
And the water stored in the tank 5 to the electromagnetic induction heating device body 1
A second line 42 that leads to
Third line 43 that guides the water with concentrated impurities to the discharge part 3
And a fourth line 44 for returning the water in a gas-liquid state in which steam and hot water are mixed from the electromagnetic induction heating device main body 1 to the tank 5.
And a fifth line 45 for discharging the vapor separated in the tank 5 to the outside.

As shown in detail in FIG. 3, the main body 1 of the electromagnetic induction heating device is a non-metallic pipe 1 forming a fluid passage.
The heating element 12 is housed in the inside 1, and the working coil 13 is wound around the outer circumference of the pipe 11. Pipe 11
For example, water 14 entering from the lower side is heated so as to boil the water by passing through the fluid passage in the heating element 12 and become a gas-liquid state 15 in which steam and hot water are mixed, and then the upper side of the pipe 11 Is discharged from the outlet in the gas-liquid state 16 in which steam and hot water are mixed. At this time, the impurities in the water are concentrated into hot water and are carried into the tank 5 together with the hot water. Since the heat exchanging property between the heating element and water is extremely high, the temperature difference between the heating element and the water is small, so that impurities are less likely to be deposited on the heating surface. Even if impurities are deposited, the vibrations generated by electromagnetic induction prevent them from adhering to the heating element 12, and the deposited impurities are carried into the tank 5 together with water in a gas-liquid state in which steam and hot water are mixed.

Returning to FIG. 1, water is the main body 1 of the electromagnetic induction heating device.
It is heated in the state of, and becomes a gas-liquid state in which steam and hot water are mixed, and is led to the upper portion of the tank 5 by the fourth line 44. The hot water flows down to the water surface where water is accumulated, the steam remains in the space above the tank 5, and is separated into the steam and the hot water.

The vapor above the tank 5 is discharged to the outside through the fifth line 45. On the other hand, makeup water is supplied as water to the tank 5 through the supply unit 2 by the first line 41. The make-up water is adjusted by the supply unit 2 so that a certain amount of water enters the tank 5. The liquid level sensor 7 and the liquid level controller 8 are preferably automatically controlled for this adjustment.

The water in the tank 5 is supplied to the electromagnetic induction heating apparatus main body 1 by a second line 42. At this time,
It is preferable that the water surface position in the tank 5 is a position where the electromagnetic induction heating device body 1 is filled with water, and the outlet of the fourth line 44 on the tank 5 side is located above the water surface in the tank 5. In such a state, water is sent from the tank 5 to the electromagnetic induction heating apparatus main body 1 and heated by the electromagnetic induction heating apparatus main body 1 to be a gas-liquid state in which the steam and hot water are mixed, Self-circulation that returns to the tank 5 occurs due to the rising force of gas and liquid in the heating section. However, a pump can be used in this circulation circuit to control the circulation speed.

By this circulation, the impurities in the water are concentrated in the tank 5. If the impurity concentration becomes high, the impurities may be precipitated. Therefore, before the impurity concentration reaches such a level, a third line 43 branched from the second line 42 at the lower portion of the tank is used to provide a necessary amount of impurities in the tank 5. The concentrated water is guided to the discharge part 3 and drained. After that, water is replenished by the supply unit 2. Concentration sensor 9
It is preferable that the discharge amount controller 10 is used to automatically discharge the water in which the necessary amount of impurities are concentrated from the discharge unit 3 when the impurity concentration becomes a certain amount or more.

Furthermore, by using the liquid level sensor 9 and the liquid level controller 10 in combination with the concentration sensor 9 and the discharge amount controller 10, if the impurity concentration of water exceeds a certain amount, the impurities are automatically added. It is also preferable to perform an automatic control for discharging the concentrated water and automatically replenishing the water.

Another embodiment of the present invention will be described with reference to the drawings. FIG. 2 is a device configuration diagram of a water impurity removing apparatus provided with the heat exchanger 6 according to the present invention.

In FIG. 2, the heat exchanger 6 is used to condense steam into water, and makeup water is used as a cooling medium for the heat exchanger 6. Compared to FIG. 1, the heat exchanger 6
Is added, and the pipeline has been changed accordingly. The pipeline uses the raw water of the heat exchanger 6
First line 41 leading to the tank 5 via the supply unit 2
a, a second line 42 that guides the water stored in the tank 5 to the electromagnetic induction heating device body 1, and a third line 43 that branches from the second line 42 and guides the water in which impurities are concentrated to the discharge part 3. And a fourth line 44 for returning water in a gas-liquid state in which steam and hot water are mixed from the electromagnetic induction heating device body 1 to the tank 5, and the steam separated in the tank 5 for the heat exchanger 5th, leading to 6 and condensing into water, leading to the outside
It consists of a line 45a. A tank 46 for storing the treated water from the heat exchanger 6 is connected via a switching valve.

The operation of the water impurity removing device having such a configuration, which is different from FIG. 1, will be described. Vapor from the electromagnetic induction heating device main body 1 above the tank 5 is the fifth line 4
It is guided to the heat exchanger 6 by 5a. The steam is condensed into water by the heat exchanger 6 and discharged as treated water to the outside. On the other hand, using makeup water as a cooling medium in the heat exchanger 6, the makeup water warmed by heat exchange with the steam is supplied as water to the tank 5 through the supply unit 2 through the first line 41a. To be done.

The heat exchanger serves to recover the latent heat of steam with water and improve the overall thermal efficiency. As the heat exchanger, a normal shell-and-tube type, a plate fin type, or the like is used, but a shell-and-tube type that is easily disassembled and can be cleaned internally is preferable. Even if the thermal efficiency is increased in this way, running energy may increase because the energy for operating the device is electric power. In this case, it is effective to use night power, which has a low power charge. Therefore, the treated water is stored in the tank 46 by operating at night, and the treated water stored in the tank 46 is used during the daytime.

Next, the detailed structure of the apparatus main body 1 which can be incorporated in the pipeline inline will be described with reference to FIG.
At both ends of the pipe 11, pipes 51 and 52 and short pipes 53 and 5 are provided.
4, the flanges 55 and 56 are connected in order.

The materials of the flanges 55, 56 and the short tubes 53, 54 are preferably corrosion resistant to water, and are made of a non-magnetic material such as SUS316 so that they are not easily affected by the magnetic flux formed by the coil 13. Austenitic stainless is used. The flange 55 and the short pipe 53 are formed into a flange with a short pipe by welding or the like, and the flange 56 and the short pipe 5 are
4 is also formed into a flange with a short pipe by welding or the like. The pipe 11 made of a non-magnetic material such as FRP, fluororesin, or ceramic is connected between the short pipes 53 and 54.

The same SUS316 socket 54a is fixed to the short pipe 54 located on the outlet side of the fluid 14 by welding or the like, and the fitting 17a for mounting the temperature sensor 17 can be screwed in. Then, by screwing the pressing metal fitting 17b into the fitting 17a, the tip of the temperature sensor 17 can be fixed in a state of being positioned near the center of the short tube 54.

The coil 13 is formed by twisting litz wires, and is wound around the outer periphery of the pipe 11 or embedded in the thickness of the pipe 11 by winding. Pipe 11
Is for holding the coil 13, defining a fluid passage, and accommodating the heating element 12 in the passage.

FIG. 4 shows the structure of the heating element 12 incorporated in the pipe 11. A first metal plate 22 and a flat second metal plate 21 bent in a zigzag chevron are alternately laminated to form a cylindrical laminated body 12 as a whole. The material of the first metal plate 22 and the second metal plate 21 is SUS4 which is a ferromagnetic material and also has corrosion resistance.
Martensitic stainless steel such as 47J1 is used. The peak (or valley) of the first metal plate 22 is the central axis 2
4, the first metal plates 22 adjacent to each other with the second metal plate 21 sandwiched therebetween are arranged so as to intersect each other at an angle α. And the adjacent first
At the intersection of the peaks (or valleys) in the metal plate 22, the first metal plate 22 and the second metal plate 21 are welded by spot welding so that they can be electrically conducted.

The second metal plate 21 and the first metal plate 22 on the front side
A first small flow path 27 inclined by an angle α is formed between the second metal plate 21 and the second metal plate 21.
The second small flow path 28 that is inclined by the angle −α is formed. The first small channel 27 and the second small channel 28 intersect at an angle of 2 × α. Further, on the surfaces of the first metal plate 22 and the second metal plate 21, holes 26 are provided as third small flow paths for causing turbulent flow of fluid. Furthermore, the surfaces of the first metal plate 22 and the second metal plate 21 are not smooth, and have fine irregularities by a satin finish or embossing. This unevenness is small enough to be ignored as compared with the height of the peak (or valley).

A high frequency current is passed through the coil 13 to form the laminated body 1
When a high frequency magnetic field is applied to 2, eddy current is generated in the entire first metal plate 22 and the second metal plate 21 by electromagnetic induction, and the laminated body 12 generates heat. At this time, the temperature distribution is an eyeball shape extending in the longitudinal direction of the first metal plate 22 and the second metal plate 21, and the central portion generates heat rather than the peripheral portion, which is suitable for heating the fluid flowing in the central portion. It has an advantage. In addition, 4 is a high frequency current generator such as an inverter that converts the AC power source 20 into a high frequency power source, and 18 and 19 are controllers for the temperature regulator and the high frequency current generator 4.

Further, a first small flow path 27 and a second small flow path 28 intersecting each other are formed in the laminated body 12 to diffuse the periphery and the center, and in addition, to form a third small passage. Due to the presence of 26, diffusion in the thickness direction between the first small channel 27 and the second small channel 28 is also performed. Therefore, these small channels 2
7, 28 cause macroscopic dispersion, diffusion, and volatilization of the fluid over the entire laminated body 12. In addition, minute unevenness on the surface causes microscopic diffusion, diffusion, and volatilization.
As a result, the fluid passing through the stacked body 12 becomes a substantially uniform flow, and a uniform contact opportunity between the first metal plate 22 and the second metal plate 21 and the fluid is obtained.

As shown in FIG. 3, the heat generating element 12 has a diameter D so as to form an annular gap Rs between the outer peripheral surface of the heat generating element 12 and the inner peripheral surface of the pipe 11, and the axis of the heat generating element 12 is arranged in the pipe 11. The core and the heating element 12 are loosely fitted so that they coincide with each other, inserted into the pipe 11 and held by the holding member 30.
The diameter D of the heating element 12 is the same as that of the fluid 14 in the device body 1.
Has an annular gap Rs between the heating element 12 and the pipe 11 which is equal to or larger than the difference in thermal expansion between the amount of thermal expansion of the pipe 11 in the radial direction and the amount of thermal expansion of the heating element 12 in the radial direction. Has been decided. Further, the holding member 30 has a metal bar 31 which is welded to the short pipe 53 on the inflow side A by welding or the like and extends in the radially inward direction, and the tip of the metal bar 31 is aligned with the axial center of the heating element 12. It is composed of a fixed non-magnetic holding rod 32. And this holding rod 32 is
It is made of non-magnetic, heat-resistant and corrosion-resistant ceramic or the like and extends from the inflow side A to the outflow side B, and the extremity thereof positions and holds the heating element 12 at a position relative to the coil 13. . Reference numeral 35 denotes a ring-shaped stopper, which is made of non-magnetic, heat-resistant and corrosion-resistant ceramic or the like, is fitted into the pipe 11 from the outflow side B of the fluid 14, and is disposed between the heat generating body 12 and the pipe 11. The heating element 12 is fixed with a gap Vs that is the same as or slightly smaller than the amount of axial thermal expansion of the heating element 12. Further, the ring-shaped stopper 35 crosses the annular gap Rs from the outflow side B in the radial direction, and the heating element 12 is provided.
It is located above, and the thermal expansion of the heating element 12 causes the heating element 1 to
The ring-shaped gap Rs is closed from the outflow side B by engaging with 2.

Then, when the fluid 14 is caused to flow from the inflow side A to the outflow side B of the apparatus main body 1 and the fluid 14 is heated by the electromagnetic induction by the coil 13 via the pipe 11 and the heating element 12, the pipe 11 and the heating element 12 are heated. Although there is a difference in the thermal expansion in the radial direction between the pipe 11 and the heating element 12, an annular gap Rs larger than the difference in thermal expansion is formed between the pipe 11 and the heating element 12, so that the difference in thermal expansion is reduced while narrowing the annular gap Rs. Absorb and heat element 1
The action of stress caused by the contact of the pipe 2 with the pipe 11 and the pushing of the pipe 11 is prevented, and the heating element 12 also thermally expands in the axial direction. Absorbed by Vs.

At this time, the fluid 14 that has flowed into the inflow side A of the apparatus 1 flows into the heating element 12 and is heated to flow into the inflow side B.
At the same time, a part of the fluid 14 tends to flow from the inflow side A directly or from the heating element 12 into the annular gap Rs, pass through the annular gap Rs, and flow to the inflow side B. However, the heat generating element 12 engages with the ring-shaped stopper 35 due to the thermal expansion in the axial direction, thereby blocking the outflow side B of the annular gap Rs and preventing the fluid 14 from directly flowing to the outflow side B. As a result, a pressure is generated in the annular gap Rs such that the fluid 14 flows from the inflow side A toward the outflow side B, and the fluid 14 that has flowed into the annular gap Rs flows into the heating element 12 by this pressure. Can be made.

Even if the heating element 12 is heated by electromagnetic induction by the coil 13, the thermal expansion of the heating element 12 does not directly affect the pipe 11, and the heating element 12 can be easily replaced. Further, even if the annular gap Rs for absorbing the thermal expansion of the heating element 12 is formed, the heating element 12 thermally expands and engages with the ring-shaped stopper 35, so that the annular gap Rs is formed.
From the outflow side B. As a result, this annular gap R
The fluid 14 flowing out to s can be made to flow into the heating element 12, and the fluid 14 can be uniformly heated by the heating element 12.

It is also possible to eliminate the annular gap Rs and the bypass flow due to the wall flow by pushing in the heating element 12 having an outer shape slightly larger than the inner diameter of the pipe 11. In this case, the thermal expansion and heat generation of the heating element 12 directly affect the pipe 11, but if the heating temperature is around 100 ° C., the resin pipe 11 can sufficiently withstand.

It has been confirmed that the efficiency of conversion from electric energy to heat energy is as high as 92% in heating by the heating element 12 having the above-mentioned structure. Since such a high heat exchange property is provided, the apparatus main body 1 becomes compact and can be incorporated inline in a pipeline.

[0038]

As described above, according to the first aspect of the present invention, since the heating portion by electromagnetic induction is provided separately from the tank, the heat transfer of the heating element heated by electromagnetic induction is performed. By increasing the area to reduce the temperature difference between the heating element and water, the precipitation of impurities on the heating surface is prevented, the impurities are concentrated in the water in the tank, and the water in which the impurities are concentrated is removed from the tank. By discharging it to the device, it is possible to achieve continuous operation of the device and facilitate maintenance. Further, since the heating section by electromagnetic induction has a very high heat exchange property and is compact, the entire apparatus becomes compact even if a large amount of water is treated.

According to the second aspect of the present invention, it is possible to ensure that the heat transfer area of the heating element heated by electromagnetic induction in the first aspect is increased to reduce the temperature difference between the heating element and water. Play.

The invention according to claim 3 has an effect of ensuring that the impurities according to claim 1 or 2 are concentrated and discharged.

The invention according to claim 4 has an effect of ensuring that continuous operation of the apparatus according to claim 1, 2 or 3 is ensured.

The invention according to claim 5 has an effect that the continuous operation of the apparatus according to any one of claims 1 to 4 can be easily performed.

In addition to the effect of the first aspect, the invention of the sixth aspect has the effect of reducing the running cost.

[Brief description of the drawings]

FIG. 1 is a device configuration diagram of a water impurity removing apparatus of the present invention.

FIG. 2 is a device configuration diagram of another water impurity removing device of the present invention.

FIG. 3 is a sectional view of an electromagnetic induction heating device.

FIG. 4 is a diagram showing a structure of a heating element.

[Explanation of symbols]

 1 heating part (electromagnetic induction heating device main body) 2 supply part 3 discharge part 4 high frequency generator 5 tank 6 heat exchanger 7 liquid level sensor 8 liquid level controller 9 concentration sensor 10 discharge rate controller 11 pipe 12 heating element (lamination) Body 13 coil 41 first line 42 second line 43 third line 44 fourth line 45 fifth line 41a first line 45a fifth line 46 tank

Claims (6)

[Claims] 1. A water impurity removing device for removing impurities such as ions by evaporation, wherein a tank is supplied with water and discharges steam, and water in this tank is received to mix steam and hot water. It comprises a heating unit for returning to the tank in a gas-liquid state, the heating unit is a pipe made of a non-magnetic material, a coil wound around the pipe, and electromagnetic induction by the coil housed in the pipe. An apparatus for removing impurities from water, comprising: a heating element to be heated; and a discharge section for discharging water in which impurities are concentrated in the tank. 2. The heat transfer area of the heating element is 1 square centimeter.
The water impurity removing device according to claim 1, wherein the water heated per torr is 0.4 cubic centimeters or less. 3. The water impurity removing device according to claim 1, wherein a sensor for detecting the concentration of the impurities is attached to the tank, and the discharging unit is controlled based on the output of the sensor. 4. A level gauge for detecting the level of water is attached to the tank, and the amount of water received in the tank is controlled based on the output of the level gauge.
Alternatively, the water impurity removing device according to the item 3. 5. The water impurity removing apparatus according to claim 1, wherein the water received from the tank to the heating unit is circulated by the ascending force of gas-liquid in the heating unit. 6. The water impurity removing device according to claim 1, further comprising a heat exchanger for exchanging heat between the steam discharged from the tank and the water supplied to the tank.