JPH11211390A - Dust removing device for heat-exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dust removing device to reliably and effectively remove dust, such as powder dust, adhered on a heat transfer surface. SOLUTION: This dust removing device comprises a moving structure 13 moved along a fluid flow passage 12 for heat-exchange with a specified gas between a heat transfer surface and the moving structure; and an air nozzle 14 moved in the vicinity of the moving structure 13 and in linkage therewith. Through blowoff operation by the air nozzle 14 moved by the moving structure 13, dust adhered on the heat transfer surface is removed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchanger for recovering heat from dust-containing combustion gas (exhaust gas) of an incinerator, a diesel engine, or the like, for removing dust or the like adhering to a heat transfer surface of a heat exchange fluid flow path. The present invention relates to a dust removing device for removing dust.

[0002]

2. Description of the Related Art Conventionally, this type of dust removing apparatus uses a scraper that moves along a heat exchange fluid flow path. FIG. 6 shows, for example, a scraper Q in which a pair of U-shaped members are joined back to back in a fluid flow path in a heat exchange plate P composed of a pair of heat transfer plates T, T in a plate heat exchanger. Then, by moving the scraper Q along the fluid flow path by an appropriate driving mechanism,
4 shows a dust removing device configured to scrape dust R adhered to an inner surface of a heat transfer plate T.

[0003]

In such a dust removing apparatus, the scraper Q moves in parallel with the inner side surface (heat transfer surface) of the heat transfer plate T while keeping a moving gap S of 1 to 2 mm. The attached dust R is scraped off at the front end face. However, a thin layer of the unscraped dust remains on the inner surface of the heat transfer plate T, and as the scraper Q reciprocates many times over time, new dust is pressed against the dust layer and consolidation occurs. As a result, a hardened dust layer R 'is formed, which causes a problem that the heat transfer efficiency is reduced.

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a dust removing device capable of reliably removing dust such as dust adhering to a heat transfer surface without remaining.

[0005]

According to a first aspect of the present invention, there is provided a dust removing apparatus for a heat exchanger, comprising a moving structure 13 which moves along a heat exchange surface along a heat exchange fluid flow path 12 with a constant gap. An air nozzle 14 that moves in conjunction with the moving structure 13 so as to remove dust attached to the heat transfer surface by the blowing action of the air nozzle 14 that moves by the moving structure 13. It is characterized by the following. In the present invention, in particular, the air nozzle 14
This is a method of removing dust by the blowing action, which can reliably remove dust such as dust attached to the heat transfer surface, and eliminates the formation of a dust layer such as compacted dust on the surface of the heat transfer plate. In addition, the heat efficiency of the heat exchanger can be maintained.

According to a second aspect of the present invention, there is provided a dust removing apparatus for a heat exchanger, comprising: a moving structure which moves along a heat exchange surface along a heat exchange fluid flow path; Air nozzle 14 that moves in conjunction with this in the vicinity
And the dust attached to the heat transfer surface is removed by the mechanical scraping action of the moving structure 13 and the blowing action of the air nozzle 14. According to the present invention, there is provided a method for removing dust by a mechanical scraping action by a moving structure 13 and a blowing action by an air nozzle 14, wherein the moving structure is disposed with a certain gap between the heat transfer surface and the moving structure. The adhering dust portion that cannot be scraped off by the body 13 can be removed, and the dust such as dust adhering to the heat transfer surface can be reliably removed without remaining.

A third aspect of the present invention is the dust removing apparatus for a heat exchanger according to the first or second aspect, wherein the movable structure 13 is provided.
Consists of a pair of scraping members 17, 17 which are arranged opposite to each other at a predetermined interval in the front and rear direction of movement and form a space 20 therebetween, and at one longitudinal end of the space 20 between the scraping members 17, 17. The air nozzle 14 is provided inward.

A fourth aspect of the present invention relates to the dust removing apparatus for a heat exchanger according to the third aspect, wherein the two scraping members 17, 1 are provided.
The space 20 formed between the air nozzles 7 is characterized in that the end opposite to the side where the air nozzle 14 is provided is closed.

According to a fifth aspect of the present invention, in the dust removing apparatus for a heat exchanger according to any one of the first to fourth aspects, the air nozzle 14 pulsates high-pressure air from the nozzle 14 as shown in FIG. It is characterized in that it is connected to a high-pressure air header 16 with an electromagnetic valve to blow out.

[0010]

1 to 3 show a plate type heat exchanger. In these figures, reference numeral 1 denotes a rectangular tubular heat exchanger body having an exhaust gas inlet 2 at an upper end and an exhaust gas outlet 3 at a lower end side. A plurality of heat exchange plates 4 having both ends opened are arranged side by side at regular intervals, and partitions 5 and 6 are provided at the upper end side and lower end side of the group of heat exchange plates 4, respectively. The flow passages are connected to the upper exhaust gas passage 7 and the lower exhaust gas passage 8 inside the heat exchanger body 1, and a hot water flow passage 9 is formed around each heat exchange plate 4 to communicate with each other. Low-temperature water inlet 10 for introducing low-temperature water to the water, and hot water outlet 1 for taking out hot water
1 is provided on the heat exchanger body 1. This plate-type heat exchanger is a well-known type, and includes a high-temperature exhaust gas flowing through the internal flow passage of each heat exchange plate 4 from top to bottom and a low-temperature exhaust gas flowing through a hot water flow passage 9 around each heat exchange plate 4. Heat is exchanged with water, and the heat of the exhaust gas is taken out in the form of warm water.

Next, a dust removing apparatus according to the present invention provided in the above plate type heat exchanger will be described.

As shown in FIG. 1 to FIG. 3, this dust removing device is arranged in the front-rear direction along the internal flow path 12 (heat exchange fluid flow path) of each heat exchange plate 4 having upper and lower ends open. (Left and right directions of the moving structure 13), and an air nozzle 14 disposed at the upper end of each moving structure 13 with the injection port facing downward and moving in conjunction with the moving structure 13. The moving structure 13 and the air nozzle 14 are reciprocated for a predetermined stroke by the driving mechanism 15, and each air nozzle 14 is moved to the high-pressure air header 16 with an electromagnetic valve 34 for blowing out high-pressure air from the nozzle of the nozzle 14 in a pulsed manner. It is connected.

The structure of the dust removing device is shown in FIGS.
More specifically, with reference to FIG.
Is a pair of scraping members 17, 17 each having a U-shaped cross section, which are opposed to each other in a back-to-back state at regular intervals in the movement direction.
17 is welded and fixed to the upper and lower connecting plates 18 and 19, and the air nozzle 14 is disposed downward at the upper end of the space 20 formed between the scraping members 17 and 17. As can be seen from FIG. 4, a narrow gap S of about 1 to 2 mm is formed between the inner surface of the heat transfer plate 4 a of the heat exchange plate 4 and the outer surface of each scraping member 17.

As shown in FIGS. 1 to 3, the drive mechanism 15 is provided with shaft casings 21, 21, 22, 22 on the upper and lower sides of the left and right sides of the heat exchanger main body 11, and the inside of the upper shaft casings 21, 21 is provided. The screw shafts 23 and 23 are arranged horizontally and are respectively supported by bearings 24, and the guide shafts 25 and 25 are horizontally disposed in the lower shaft casings 22 and 22 and are respectively supported by bearings 26. A motor 2 that can rotate forward and reverse by using one of the screw shafts 23 as a driving screw shaft.
7, the driving screw shaft 23 and the other screw shaft 23 are interlocked and connected by a sprocket chain 28, and nut members 29, 29 are screwed to the screw shafts 23, 23, respectively. The nut members 29, 29 are integrally connected by a connecting rod 30, guide members 31, 31 are respectively slidably fitted to both guide shafts 25, 25, and the upper and lower connecting plates 18, 19
Are integrally connected to the upper nut members 29, 29 and the lower guide members 31, 31, respectively.

Therefore, by activating the motor 27 and rotating the two screw shafts 23 via the sprocket chain 28, the two nut members 29, 29 move in the axial direction, whereby each moving structure 13 moves along the internal flow path 12 of each heat exchange plate 4, and the air nozzle 14 provided at the upper end of each moving structure 13 moves in conjunction with the moving structure 13. I have.
Although not shown, a stroke end detection switch of a limit switch is provided at both ends of one screw shaft 23,
When the nut member 29 moves to the end of the stroke along the screw shaft 23, the detection switch detects this, and the motor 27 operates in reverse, whereby the moving structure 13 causes the internal flow of the heat exchange plate 4 to flow. The road 12 is turned back.

As shown in FIGS. 1 to 3, one end of a flexible air pipe 32 is attached to the air nozzle 14 mounted at a fixed position above each moving structure 13 with respect to the high pressure air header 16 with a solenoid valve. Section and connect the air pipe 32
Extend rearward in the moving direction of the moving structure 13 with a sufficient bending margin, penetrate the heat exchanger body 11,
While connected to the air reservoir 33 installed outside,
An electromagnetic valve 34 is interposed in front of the air reservoir 33. Compressor 3 for supplying pressurized air to air reservoir 33
5 is connected via a connection pipe 36. In the air reservoir 33, air having a constant pressure of about 5 to 12 kg / cm ² is always accumulated by the compressor 35. The high-pressure air header 16 with the electromagnetic valve opens the electromagnetic valve 34 of each air pipe 32 at a constant time interval, thereby causing the high-pressure air (shock wave) from the air nozzle 14 of each air pipe 32 to form a pulse. It is made to blow out.

In this high pressure air header 16, FIG.
As shown in (2), the solenoid valves 34 provided on the plurality of air pipes 32 connected in parallel are not opened all at once, but are sequentially opened one by one at a fixed time interval by sequence control. The valve is to be opened. Therefore, the pressure of the air reservoir 33 does not suddenly decrease due to the opening of the solenoid valve 34, and pulsed high-pressure air consisting of an extremely high-pressure air mass, ie, a shock wave, is always obtained. In this case, the pulse interval is set to, for example, 1 to 2 seconds, and the valve opening time is set to, for example, 0.1 to 0.2 seconds.

As shown in FIG. 5, each of the air nozzles 14 is connected to a connecting plate 18 which fixes the upper end of each moving structure 13.
And the connecting rod 30 disposed on the upper side thereof, are fixed so as to penetrate vertically, and the air pipe 32 is connected via a connecting member 37 provided on the upper surface side of the connecting rod 30.

When the dust removing device having the above structure is used to remove dust adhering to the inner surface of the heat transfer plate 4a of each of the heat exchange plates 4, FIG.
As shown in FIG. 3, the moving structure 13 is moved along the internal flow path 12 of the heat exchange plate 4 while moving the moving structure 13.
When high-pressure air is blown into the space 20 between the scraping members 17 in a pulsed manner from the nozzle of the air nozzle 14 located above the heat transfer plate 14, the heat transfer plates are mechanically scraped off by the moving structure 13 that moves. While the surface layer of the dust layer thickly attached to the inner surface of the heat transfer plate 4a is scraped off, the high-pressure air blown into the space 20 between the scraping members 17 is opposed to the inner surface of the heat transfer plate 4a. When the air passes through the narrow gap S between the scraping member 17 and the outer end face of the heat transfer plate 4a, the air becomes a strong air flow and rapidly jets out of the space 20. Due to the synergistic effect of the mechanical scraping action of the moving structure 13 and the blowing action of the air nozzle 14, the dust layer adhered to the inner surface of each heat transfer plate 4a is blown off. Everything is hot It is removed until the throat perfect.

In this case, the moving structure 13 is composed of a pair of scraping members 1 opposed to each other at regular intervals in the front and rear directions of movement.
And an air nozzle 14 at one end of a vertically long space portion 20 formed between the scraping members 17.
Are arranged inward, the high-pressure air blown into the space 20 from the air nozzle 14
a, 4a are suddenly jetted out of the moving structure 13 from four front, rear, left and right gaps S formed between the left and right ends of the scraping members 17, 17, respectively. The blowing action of the air nozzle 14 can be made to work more effectively.

In this case, high-pressure air is blown from the air nozzle 14 in a pulsed manner.
An extremely high pressure air mass is instantaneously supplied to the space 20 between the scraping members 17, 17, so that the flow of air that blows off the dust can be strengthened, and as a result, dust having a strong adhesive force can be removed. Can also be reliably removed.

The space 20 between the scraping members 17, 17 forming the moving structure 13 is closed from the air nozzle 14 to the space 20 because the upper and lower ends thereof are closed by the connecting plates 18, 19. The blow-by of the blown high-pressure air is eliminated, whereby the flow of the air for blowing off the dust can be further strengthened, and the dust removing effect can be further enhanced. In this case, both scraping members 1
Of the upper and lower ends of the space 20 between the spaces 7 and 17, the ends opposite to the side where the air nozzle 14 is arranged may be closed.

Further, the dust removing device is effective for removing dust at both ends of the internal flow path 12 of the heat exchange plate 4 in the moving structure moving direction. That is, as can be seen from FIG. 4, the end of the plate 4 for heat exchange has a triangular or arc-shaped cross section, forming a so-called dead space. The attached dust cannot be scraped off by the moving structure 13, but at such an end, high-pressure air blown from the air nozzle 14 can generate a vortex as shown by the bent arrow in FIG. 4. Also, dust adhering to the end portion can be effectively removed, and no condensation or compression of the dust occurs at the end portion, whereby thermal efficiency can be maintained.

In this embodiment, the moving structure 13 is formed by a pair of scraping members 1 each having a U-shaped cross section.
Although they are formed by the members 7 and 17, they may be formed by a pair of scraping members each having an I-shaped cross section.

In this embodiment, the moving structure 13
Was described along the internal flow path 12 of the plate 4 for heat exchange, the dust removing device of the present invention has the moving structure 13 outside the plate 4 for heat exchange. The moving structure 13 is disposed in the fluid flow path formed between the outer surfaces of the adjacent heat exchange plates 4, 4, and is disposed on the outer surface of the heat transfer plate 4 a of each heat exchange plate 4. The present invention can also be applied to the case of removing attached dust.

In this embodiment, the air nozzle 14
Is connected to a high-pressure air header 16 with an electromagnetic valve that blows out high-pressure air from the nozzle 14 in a pulsed manner. However, the air nozzle 14 is directly connected to a compressor, and a simple high-pressure air is injected from the nozzle 14. You may make it do.

[0027]

According to the dust removing apparatus of the first aspect of the present invention, there is provided a moving structure that moves along the fluid flow path, and an air nozzle that moves in the vicinity of the moving structure in conjunction with the moving structure. Since the dust such as dust adhered to the heat transfer surface is removed by the blowing action of the air nozzle moved by the moving structure, the dust such as dust adhered to the heat transfer surface can be reliably removed. No dust layer such as compacted dust is formed on the surface of the heat exchanger, and the thermal efficiency of the heat exchanger can be maintained.

According to a second aspect of the present invention, there is provided a dust removing apparatus including a moving structure moving along a fluid flow path, and an air nozzle moving in the vicinity of the moving structure in conjunction with the moving structure. A moving structure in which dust such as dust attached to the heat transfer surface is removed by the scraping action of the structure and the blowing action of the air nozzle, and is arranged with a certain gap between the heat transfer face and the heat transfer face. The dust particles that cannot be scraped off depending on the body are removed by the blowing action of the air nozzle, so that dust such as dust adhering to the heat transfer surface can be reliably removed without remaining, and the heat transfer plate A dust layer such as compacted dust is not formed on the surface, and the heat efficiency of the heat exchanger can be maintained.

In particular, the dust removing device is effective for removing dust at both ends in the moving direction of the moving structure in the internal flow path of the heat exchange plate. That is, the end of the heat exchange plate has a triangular or arcuate cross section, forming a so-called dead space.
Although the dust attached to the end cannot be scraped off by the moving structure, the swirl can be generated at the end by the air blown from the air nozzle. Effective removal can be achieved, and no condensation or compression of dust occurs at the end portion, thereby maintaining thermal efficiency.

According to the third aspect, the moving structure is formed by a pair of scraping members which are opposed to each other at regular intervals in the front and rear direction of the moving direction, and a longitudinal direction of a space formed between the scraping members. Since the air nozzle is arranged inward at one end, the high-pressure air blown into the space from the air nozzle is transferred between the heat transfer surface facing left and right and the left and right ends of each of the scraping members. Abruptly jetting out of the moving structure from the four gaps formed before, after, left and right, thereby making it possible to make the blowing action of the air nozzle work more effectively, thereby further enhancing the dust removing effect. it can.

According to the fourth aspect, the space formed between the scraping members is closed at the end opposite to the end where the air nozzle is provided. The blow-by of the high-pressure air blown into the air is eliminated, whereby the flow of air for blowing off the dust can be further strengthened, and the dust removing effect can be further enhanced.

According to the fifth aspect, the air nozzle is connected to a high-pressure air header with an electromagnetic valve for blowing high-pressure air from the nozzle in a pulsed manner, so that the high-pressure air is blown out from the nozzle in a pulsed manner. Therefore, the flow of the air that blows off the dust can be further increased, and the dust having a strong adhesive force can be reliably removed.

[Brief description of the drawings]

FIG. 1 is a vertical sectional side view of a heat exchanger provided with a dust removing device according to the present invention.

FIG. 2 is a partial cross-sectional plan view of the upper part of the heat exchanger, which is partially horizontal in section.

FIG. 3 is a cross-sectional plan view in which a lower side of the heat exchanger is horizontally sectioned.

FIG. 4 is an enlarged cross-sectional view showing a main part of the dust removing device.

5A is an enlarged perspective view showing the upper end side of the moving structure, and FIG. 5B is an enlarged perspective view showing the lower end side of the moving structure.

FIG. 6 is a cross-sectional view showing a conventional dust removing device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Heat exchanger main body 4 Heat exchange plate 4a Heat transfer plate 12 Internal flow path of heat exchange plate (fluid flow path for heat exchange) 13 Moving structure 14 Air nozzle 15 Drive mechanism 16 High pressure air header with solenoid valve 17 Scratching Removing member 20 Space between both scraping members 32 Air pipe 33 Air reservoir 34 Solenoid valve 35 Compressor

Claims (5)

[Claims] 1. A moving structure comprising: a moving structure moving along a heat transfer surface along a heat exchange fluid flow path with a fixed gap; and an air nozzle moving in the vicinity of the moving structure in conjunction therewith. A dust removing device for a heat exchanger, which removes dust attached to a heat transfer surface by a blowing action of an air nozzle moved by a body. 2. A moving structure, comprising: a moving structure moving along a heat transfer surface along a heat exchange fluid flow path with a fixed gap; and an air nozzle moving in the vicinity of the moving structure in conjunction therewith. A dust removing device for a heat exchanger, which removes dust attached to a heat transfer surface by a mechanical scraping action by a body and a blowing action by an air nozzle. 3. The moving structure comprises a pair of scraping members which are opposed to each other at regular intervals before and after the moving direction to form a space therebetween, and one end in the longitudinal direction of the space between the two scraping members. The dust removing device for a heat exchanger according to claim 1 or 2, wherein the air nozzle is disposed inwardly. 4. The dust removal of a heat exchanger according to claim 3, wherein an end of the space formed between the scraping members on the side opposite to the side where the air nozzle is provided is closed. apparatus. 5. The dust removing device for a heat exchanger according to claim 1, wherein the air nozzle is connected to a high-pressure air header with an electromagnetic valve that blows out high-pressure air from the nozzle in a pulsed manner. .