JP3004918B2 - Apparatus for removing boiler and other pipe adhesion products - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scale formed in an aqueous solution in a boiler and its piping, a piping of a heating device in a cold district, and a cooling piping of a cooling tower, for example, to peel off a product attached to an inner wall of the piping. The present invention relates to a stripping apparatus and a stripping method for a product adhering to a pipe such as a boiler, and the term "peeling" includes preventing a product from adhering to a boiler or a pipe.

[0002]

2. Description of the Related Art Conventionally, products called scales or scales are accumulated in, for example, boilers and pipes, thereby inhibiting the flow of steam and reducing the thermal efficiency of the boiler itself. This necessitated periodic removal of this product in order for the boiler to operate properly.

As a conventional example of removing this, first, a method of washing with an acid solution to which a corrosion inhibitor or the like is added (for example, JP-A-56-2897, JP-A-52-82639, No. 54-117327), and a second method is to mix pellets made of a material having a specific gravity close to that of water into circulating water to remove scale on the inner surface of the tube wall (for example, Japanese Patent Laid-Open No. 52-53)
No. 554), and the third method is to change the circulating water or the flow velocity without using chemicals or pellets, and to remove and remove the scale of the tube wall by utilizing the difference in the expansion coefficient between the tube wall and the scale (for example, Japanese Patent Laid-Open JP-A-52-28253, JP-A-54-5104
No.) is known.

Further, as a fourth conventional example, an electric field and a magnetic field are applied from the outside of the boiler to prevent local corrosion of the boiler, soften circulating water by magnetic action, and peel off scale attached to the inner wall of the boiler. (Patent No. 1215
No. 830), but the point of the technology of this device is to change the crystal structure of CaCO ₃ contained in the circulating water from argonite to calcite by magnetic action to make the scale lighter and finer and to peel off. .

[0005]

In the first to third prior arts, since the operation of the boiler must be stopped, a high cost is required. Furthermore, in any of the above-mentioned conventional examples, in order to treat the scale and the products in the circulating water adhered to the boiler cooling tower and the piping inner wall, the boiler operation was periodically stopped, the inside was washed, and then the exfoliated. In order to take out the scale outside, maintenance of a boiler, a cooling tower, and the like requires a great deal of cost and time. In the fourth conventional example, the product in the boiler is not separated by the action of an electromagnetic field.

[0006]

Accordingly, an object of the present invention is to provide:
By eliminating the need to clean the inside of the piping, maintenance and inspection can be simplified, costs can be reduced, and when applied to a boiler, the thermal efficiency of the boiler is prevented from lowering. It is an object of the present invention to provide an apparatus for removing adhered products from piping, such as a boiler or a cooling tower, which can be made unnecessary.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first feature of the present invention is that an adhesion product containing ferromagnetic fine particles generated in an aqueous solution of a pipe is subjected to electromagnetic induction induced in the pipe by a magnetic field from outside the pipe. An exfoliation device in which an electric current flows along a wall to cause electrolysis, and exfoliation of the adhesion product due to the electrolysis and Lorentz force is controlled by an external magnetic field.

A second feature is that a ground wire is attached along a pipe from a device for mounting an external magnet to facilitate current flow along the pipe, and a synergistic effect of electromagnetic induction by an electric field and a magnetic field of the ground wire. As a result, the current flowing along the inner wall of the pipe increases, the amount of electrolysis also increases, and the separation of the adhered product is promoted.

[0009]

First, the chemical basis of a product containing ferromagnetic fine particles generated in an aqueous solution of a boiler and a pipe will be described.

In the schematic diagram of the boiler shown in FIG. 1, steam is generated in a combustion chamber 1, and the generated steam is
The steam is separated into steam and water in the heat exchanger 2, and the steam is sent to a predetermined place by a pipe P2, consumes heat, and returns to the combustion chamber 1. The water and some of the steam return to the combustion chamber 1 via the pipe P3. The water lost in the circulation process is supplied to the combustion chamber 1 from the supply pipe P4. In the course of this circulation, a product containing ferromagnetic fine particles is generated.

To briefly explain the process of this generation, tap water is usually used for the steam generated in the combustion chamber 1, and this water is usually CaCO ₃ , MgCo
₃ and compounds such as SiO ₂ . When the boiler is operating, the disappearance and replenishment of water vapor are repeated, and as a result, the concentration of Ca ²⁺ and Mg ²⁺ gradually increases,
Compounds such as CaCO ₃ and MgCO ₃ also increase. Further, since the combustion chamber 1 and the pipes P1, P2, and P3 are made of iron, they are gradually dissolved and corroded, and iron hydroxide (II) [Fe (OH) ₂
] And iron (III) hydroxide [Fe (OH) ₃ ] are precipitated. The aqueous solution becomes alkaline by these reactions, and the pH becomes 9.5 to 11.0. In addition, iron hydroxide (I
I) and iron (III) hydroxide are further oxidized to produce magnetite (Fe ₃ O ₄ ). Simultaneously with this oxidation reaction, ionized Fe ²⁺ and Fe ³⁺ co-precipitate in an alkaline aqueous solution to form ferromagnetic fine particles (magnetite, Fe ₃ O
₄ ) is generated.

Next, in a boiler, CaCO ₃ , MgCO ₃
Table 1 and FIG. 2 show that iron and Fe ₃ O ₄ are produced.
A description will be given based on (A, A1, A2).

[0013] The product was collected from the boiler, finely pulverized, dispersed in an alcohol solution, and subjected to magnetic separation with a permanent magnet. The sample (product) A collected from inside the boiler was separated into a sample (magnetically attached matter) A1 attached to the magnetic pole and a sample (non-magnetically attached matter) A2 not attached to the magnetic pole by magnetic separation. Table 1 shows samples A, A1,
It is a result of periodically measuring the element of A2.

[0014]

[Table 1]

Sample A contains about 50% of the total of CaCO ₃ and MgCO ₃ , about 17 to 20% of SiO _{2 and} about 20 to 24% of Fe ₃ O ₄ , and there is no difference depending on the boiler.

FIG. 2 shows the results of identification of the structure and structure of each sample by X-ray diffraction. In FIG.
In A1 and A2, C is Calcite, S is Spi
The spectrum is consistent with the nel type crystal structure. The strongest spectrum of sample A is Calcite,
Since there is also a Spinel spectrum, the sample A
It can be seen that Fe ₃ O ₄ of ferromagnetic fine particles having an inel type structure is included. The strongest spectrum of the sample A1 has a Spinel type structure. The strongest spectrum of sample A2 is Calcite.

The specific structure of the peeling device will be described below based on the above results. First, with reference to FIGS. 3 to 5, the structure of a device A for exfoliating a product containing ferromagnetic fine particles generated in a boiler will be described.

In FIG. 3, a power distribution device 3 provided in a peeling device D has a built-in transformer and a resistor, and has an AC / AC
100V, the output side can be taken out as DC / 0.8A. A lead wire is connected from the power distributor 3 to the pipe, and a weak current flows through the pipe to have an anticorrosion effect. A permanent magnet 4 is provided on the lower surface of the power distributor 3, and a pair of soft iron pieces 5 and 5 are attached to the tip of the permanent magnet, and a magnetic field induced from the permanent magnet 4 is applied to the soft iron pieces. N and S pole pieces are configured on the right and left sides. The tip surfaces of the soft iron pieces 5, 5 are formed in arc shapes 5a, 5a corresponding to the shapes of the outer peripheral surfaces of the pipes P1, P3 of the boiler, and are in contact with the pipes. Therefore, when the soft iron pieces 5 and 5 are mounted on the permanent magnet 4 and mounted outside the pipes P1 and P3, a magnetic field is generated in the aqueous solution in the pipes. This magnetic field causes a current to flow along the wall based on Faraday's electromagnetic induction. FIG.
When the soft iron pieces 5 and 5 are mounted on the permanent magnet 4 and mounted outside the pipes P1 and P3, the magnetic poles N and S generate magnetic lines of force B in the pipe. A current i flows along. Due to the current i, electrolysis occurs between the pipe walls of the pipes P1 and P3 and the adhered product, and at this time, the Lorentz force F = qBV acts, so that the adhered product is gradually removed. Further, the aqueous solution in the pipe is alkaline with a pH value of 9.5 to 11.0, and the aqueous solution is ionized as H ₂ O → H ⁺ OH ⁻ . Although this H ⁺ is not a metal ion, it is in the ionization train where it ionizes to become a cation, and the magnitude of the ionization tendency is Fe ²⁺ > H
⁺ , The iron atom emits an electron, that is, is oxidized to an iron ion (Fe ²⁺ ), and the electron is received by the hydrogen ion in the aqueous solution, that is, is reduced to a simple hydrogen H
₂ results. Therefore, iron is more likely to become a cation than hydrogen. As a result, the aqueous solution becomes the anode (+) and the iron becomes the cathode (-), and the current i flows from the aqueous solution toward the pipe. This current i easily flows along the pipe, and flows in the same direction as the current i generated by electromagnetic induction. As a result, the flowing current i
Is further increased, and the amount of adhesion products electrolyzed is also increased, so that the amount of adhesion products to be exfoliated is also increased.

FIG. 5 shows the relationship between the magnetic field lines and the current according to Faraday's law of electromagnetic induction. In FIG. 4, the lines of magnetic force B are generated from the N pole to the S pole, and the direction of the current i at this time is parallel to the lines of magnetic force. As a result, the current i flows along the pipe, which is shown in FIG.
Is the relationship between the magnetic field line B and the current i.

The relationship between the magnetic field (direction of the line of magnetic force) generated by electromagnetic induction of Faraday, the direction of current flow at that time, and the Lorentz force F (force) generated at that time is expressed using the index finger, middle finger and thumb of the left hand. That is, Fleming's left hand rule, in which the index finger indicates the direction of the magnetic force line B, the middle finger indicates the direction of the current i, and the thumb indicates the direction of the Lorentz force F.

[0021]

By using the stripping device according to the present invention, products adhering to piping such as a boiler, a heating device and a cooling tower can be stripped and removed, so that cleaning of the boiler and the like can be performed while operating the boiler. In addition, the periodic maintenance can be simplified, and the cost for maintenance of the boiler and the like can be reduced. Further, since the adhesion of the product is reduced, a decrease in the thermal efficiency of the boiler or the like can be prevented, and the cleaning becomes easy.
As a result, the cost required for stripping and removing the product can be reduced. In particular, in the present invention, the separation and removal of the product can be controlled by an external magnetic field, and the separation operation can be performed automatically. Of course, if this peeling device is installed in the pipe from the beginning, the adhesion of the product to the pipe can be prevented.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a boiler.

FIG. 2 is an X-ray analysis graph of a product A, a magnetically attached product A1, and a non-magnetically attached product A2.

FIG. 3 is a schematic view of an adhesion product peeling device.

FIG. 4 is a schematic diagram of a peeling process by electromagnetic induction, in which a peeling device is attached to FIG. 3;

FIG. 5 is a schematic diagram of Faraday electromagnetic induction.

[Explanation of symbols]

 P1 piping P2 piping P3 piping D Peeling device 3 Distributor 4 Magnet (permanent magnet)

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C25F 7/00

Claims (3)

(57) [Claims] (1)Boiler or other piping inside the piping
Is equipped with a permanent magnet that generates a leakage magnetic field, Leakage magnetic field generated in the pipe is changed to water flowing in the pipe.
An electric current is generated by passing the solution and cutting the magnetic field lines,
When this current flows along the pipe wall,
The amount of adhering products generated on the pipe wall by gas decomposition
Action of Lorentz force generated by solution action and electromagnetic induction
The synergistic effect with the stripping action on the pipe adhesion products
It can be induced to peel off the adhered products on the pipe wall That
FeatureBoilerStripping device for pipe adhesion products. 2. The method according to claim 1, wherein the leakage magnetic field is
The above-mentioned piping is caused by the passage of the alkaline aqueous solution flowing through the piping.
Current flowing along the pipe wall of the
Peeling action caused by Lorentz force and adhesion of the pipe wall
H ⁺ and Fe generated in the product and the above alkaline aqueous solution
^The current generated by the difference in ²⁺ ionization tendency is directed toward the tube wall
Work caused by electrolysis caused by flowing into
Induces a synergistic effect with the application to peel off the adhered products on the pipe wall
An apparatus for removing a product attached to a pipe such as a boiler, which is capable of being used. 3. The method according to claim 1, wherein the pH of the aqueous solution is alkaline at 9.5 to 11.0, the aqueous solution is ionized as H ₂ O → H ⁺ + OH ^−, and H ⁺ ions ionization tendency than iron ions Fe ^2+> H ⁺ and aqueous anode becomes to small, the piping Kuwawa and the current by the current and the electromagnetic induction flowing along the <br/> wall I Do cathode
A synergistic effect is induced, and the separation of the adhered product can be further promoted by these electric currents .