JPH085013A - Perforated plate cleaning device for fluidized bed type/ heat exchanger - Google Patents

Abstract

PURPOSE:To provide a cleaning device capable of removing soot or dust adhered to the lower surface of a perforated plate for a fluidized bed type heat exchanger. CONSTITUTION:In a fluidized bed type heat exchanger, a perforated plate 2, having a multitude of venting holes, is provided at the substantial center in a casing, provided with an exhaust gas inlet port 1a and an exhaust gas outlet port 1b, and a solid grain layer 3, consisting of solid grains and having a proper thickness, is formed on the perforated plate 2 while a heat transfer tube 4 is inserted into the solid grain layer 3. Single or a plurality of high-pressure air discharging tube 9 having a plurality of nozzles 9a are provided below the perforated plate 2 and a high-pressure air supplying passage 11, providing the high-pressure air discharging tube 9 with high-pressure air, is connected to the high-pressure air discharging tube 9 while the high-pressure air supplying passage 11 is provided with a solenoid valve 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a porous plate cleaning device for a fluidized bed heat exchanger using exhaust gas emitted from a diesel engine or the like.

[0002]

2. Description of the Related Art Conventionally, a fluidized bed heat exchanger of this type has an exhaust gas inlet 21a and an exhaust gas outlet 2 as shown in FIGS.
A porous plate 22 having a large number of vent holes is provided in a substantially central portion of a casing 21 having 1b, and a solid particle layer 23 of solid particles (for example, silica sand) having an appropriate thickness is formed on the porous plate 22. are doing. In the casing 21, a heat transfer tube 24, which is a substantially U-shaped pipe for transferring water as a fluid to be heated, is provided, and the U-shaped heat transfer tube 24 is provided.
One parallel part is inserted in the solid particle layer 23, and the other parallel part is arranged above the solid particle layer 23.
The tip of one of the parallel portions is connected to the water intake passage 25, and the tip of the other parallel portion is connected to the water outlet passage 26. The baffle plate 2 is provided near the lower part of the exhaust gas outlet 21b.
7 is provided to prevent the outflow of solid particles scattered by the inflow of exhaust gas. In the figure, 28 is the perforated plate 2
2 is a rotation type cleaning device equipped with a brush provided on the lower surface of 2.

By the way, in the fluidized bed heat exchanger having the above structure, during normal operation, high-heat exhaust gas flowing from the exhaust gas inlet 21a flows from the exhaust gas inlet 21a to the exhaust gas outlet 2a.
Although it passes toward 1b, at this time, it jets out into the solid particle layer 23 from the ventilation hole of the perforated plate 22 provided in the casing 21. By the jet of the exhaust gas, the solid particle layer 23 is vigorously stirred and heated to be in a fluidized state, and a so-called fluidized bed is formed. On the other hand, the two parallel portions of the heat transfer tube 24 are both in and in contact with this fluidized bed, and the water flowing into the heat transfer tube 24 from the water intake passage 25 passes through the heat transfer tube 24. Meanwhile, after being heated by the fluidized bed, it flows out from the water extraction passage 26 and circulates in the hot water or steam circulation system of the boiler.

When the fluidized bed heat exchanger is operated for a long time, soot and dust contained in the exhaust gas during that time adhere to the lower surface of the porous plate 22 to block the ventilation holes and hinder the flow of the exhaust gas. . Therefore, the cleaning device 28 is operated as shown in FIG. 5 to clean the lower surface of the perforated plate 22. However, the rotary cleaning device 28 equipped with the brush has the following problems. (1) The tip of the brush is caught in the ventilation hole of the perforated plate due to the deformation of the brush, and the pulsation of the exhaust gas causes the brush to drop or become inoperable. (2) Due to the structure, the entire lower surface of the perforated plate cannot be cleaned. (3) Since one brush is operated and cleaned, the operating range is large, and exhaust gas concentrates on the brush moving part at the start of brush operation, causing problems such as poor flow of the solid particle layer and scattering of solid particles. To do. (4) The flow of exhaust gas is obstructed at the stopping portion of the brush, and a poor flow portion of the solid particle layer occurs.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a perforated plate cleaning device for a fluidized bed heat exchanger which can solve the above-mentioned problems of the conventional rotary cleaning device. .

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and the invention of claim 1 is such that a substantially central portion in a casing having an exhaust gas inlet and an exhaust gas outlet is provided. A flow for providing a perforated plate having a large number of ventilation holes, forming a solid particle layer of solid particles on the perforated plate with an appropriate thickness, and inserting a heat transfer tube into the solid particle layer to recover exhaust heat In the layered heat exchanger, one or more high-pressure air discharge pipes having a plurality of nozzles are provided below the perforated plate, and a high-pressure air supply path for supplying high-pressure air is connected to the high-pressure air discharge pipes. An electromagnetic valve is provided in the supply passage, the invention of claim 2 is characterized in that the high-pressure air discharge pipe is rotatably provided, and the invention of claim 3 is characterized in that the high-pressure air discharge pipe is provided. Characterized by being provided so as to be slidable in the axial direction

[0007]

According to the present invention, high pressure air is blown from the nozzle of the high pressure air discharge pipe provided on the lower surface of the perforated plate to remove soot and dust adhering to the lower surface of the perforated plate.

[0008]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a schematic explanatory view of a first embodiment showing the arrangement of each device of a fluidized bed heat exchanger embodying the present invention. In the figure, 1 is a casing provided with an exhaust gas inlet 1a and an exhaust gas outlet 1b, and 2 is a perforated plate having a large number of vent holes provided in a substantially central portion of the casing 1. A solid particle layer 3 made of solid particles (for example, silica sand) and having an appropriate thickness is formed on the porous plate 2. Reference numeral 4 denotes a heat transfer tube made of a substantially U-shaped pipe for transferring water as a fluid to be heated. One parallel part of the U-shape is inserted into the solid particle layer 3 and the other parallel part is It is arranged above the solid particle layer 3. Reference numeral 5 is a fin attached to the parallel portion of the heat transfer tube 4 to improve heat exchange efficiency. 6 is a water intake path,
Reference numeral 7 is a water take-out path, which is connected to the heat transfer tubes 4 and has the other end connected to hot water of the boiler or a steam circulation system. 8 is a baffle plate which prevents the outflow of solid particles scattered by the inflow of exhaust gas.

As shown in FIGS. 1 and 2, the perforated plate cleaning apparatus according to the present invention is provided with a plurality of high pressure air discharge pipes 9 having a plurality of nozzles 9a in the vicinity of the lower surface of the perforated plate 2. Communication pipe 10 in which one end face of each air discharge pipe 9 is sealed and both end faces are sealed in the other end face
And a high pressure air supply path 11 for supplying high pressure air to the connecting pipe 10, a quick open solenoid valve 12 is inserted in the middle of the high pressure air supply path 11, and the other end is connected to a compressor not shown. Connected.

Next, the operation of the fluidized bed heat exchanger having the above construction will be described. At the exhaust gas inlet 1a of the casing 1,
High-heat exhaust gas flows from an exhaust duct (not shown) connected to an exhaust gas supply source (diesel engine or the like).
The inflowing high-heat exhaust gas passes from the exhaust gas inlet 1a toward the exhaust gas outlet 1b, but at this time, it is ejected into the solid particle layer 3 from the ventilation hole of the perforated plate 2 provided in the casing 1. Due to the jet of the exhaust gas, the solid particle layer 3 is vigorously stirred and heated to be in a fluidized state, so that a so-called fluidized bed is formed. On the other hand, the two parallel portions of the heat transfer tube 4 are both in this fluidized bed and are in contact therewith,
The water that has flowed into the heat transfer tube 4 from the water intake path 6 is heated by the fluidized bed while passing through the heat transfer tube 4, and then flows out from the water extraction path 7 to flow in the hot water or steam circulation system of the boiler. Circulate.

When the fluidized bed heat exchanger is continuously operated for a long time, soot and dust in the exhaust gas adhere to the lower surface of the perforated plate 2 to block the ventilation holes and hinder the flow of the exhaust gas. Based on the above, the solenoid valve 12 of the high pressure air supply path 11 is opened for a predetermined time. By opening the solenoid valve 12, high pressure air is blown to the entire lower surface of the perforated plate 2 from the nozzles 9a of the respective high pressure air discharge pipes 9 through the communication pipes 10 to remove soot and dust adhering thereto. And improve the circulation of the ventilation holes.

Next, a second embodiment will be described with reference to FIG. The same members as those in the first embodiment are designated by the same reference numerals, and the duplicated description will be omitted. In the second embodiment shown in FIG. 3, bearing portions 13 are provided on both side walls (in this embodiment, parallel to the heat transfer tube 4) in the casing 1 near the lower surface of the perforated plate 2.
Both ends of a high-pressure air discharge pipe 9 having a plurality of nozzles 9a are rotatably inserted into the bearing portion 13, one end face of the high-pressure air discharge pipe 9 is sealed, and a rotation (not shown) is provided on this end face. Means (automatic or manual) are provided, and a high pressure air supply path 11 for supplying high pressure air is connected to the other end surface.

The operation of the second embodiment shown in FIG. 3 is similar to that of the first embodiment, in which the solenoid valve 12 of the high-pressure air supply passage 11 is opened for a predetermined time based on a preset operating time. The high-pressure air discharge pipe 9 is rotated through a predetermined angle in conjunction with the opening of the electromagnetic valve 12.
By rotating the high-pressure air discharge pipe 9, high-pressure air is blown from the nozzle 9a onto the entire lower surface of the porous plate 2, soot and dust adhering to the high-pressure air can be removed to improve the circulation of the ventilation holes.

Next, a third embodiment will be described with reference to FIG. The same members as those in the first and second embodiments are designated by the same reference numerals, and the duplicated description will be omitted. In the third embodiment shown in FIG. 4, bearing portions 13 are provided on both side walls (in this embodiment parallel to the heat transfer tube 4) in the casing 1 near the lower surface of the perforated plate 2, and a plurality of bearing portions 13 are provided in the bearing portion 13. A high-pressure air discharge pipe 9 having a nozzle 9a is slidably inserted so as to penetrate the both side walls, one end surface of the high-pressure air discharge pipe 9 is sealed, and a slide means (not shown) is attached to this end portion. A high-pressure air supply path 11 for supplying high-pressure air is slidably connected to the other end surface of the quick-open solenoid valve 1 in the middle of the high-pressure air supply path 11.
2 is inserted and the other end is connected to a compressor (not shown).

The operation of the third embodiment shown in FIG. 4 is, similar to the first and second embodiments, that the solenoid valve 12 of the high pressure air supply passage 11 is opened for a predetermined time based on a preset operating time. Then, interlocking with the opening of the solenoid valve 12, the high-pressure air discharge pipe 9 is slid back and forth between the predetermined dimensions through the slide means. By moving the high-pressure air discharge pipe 9 back and forth, high-pressure air is blown from the nozzle 9a onto the entire lower surface of the porous plate 2, soot and dust adhering to the high-pressure air can be removed to improve the circulation of the ventilation holes.

In the above embodiment, the fixing system, the rotating system, and the sliding system were described for the high-pressure air discharge pipe 9, but the present invention is not limited to the above embodiment, and for example, the rotating system can be used. By combining the method and the sliding method, the high pressure air discharge pipe 9 is slid while rotating,
The cleaning effect can be improved. Therefore, they can be appropriately selected or combined depending on the implementation.

[0017]

As described above, according to the present invention, a plurality of high pressure air discharge pipes provided with a plurality of nozzles are provided below the porous plate of the fluidized bed heat exchanger, and high pressure air discharge pipes are provided with high pressure air. Since the high-pressure air supply path for supply is connected to blow the high-pressure air to the lower surface of the perforated plate, soot and dust adhering to the lower surface of the perforated plate can be removed and the circulation of the ventilation holes can be improved. Therefore, it is possible to eliminate the insufficient cleaning of the lower surface of the perforated plate, the obstruction of exhaust gas flow, etc., as in the conventional case, and to efficiently perform heat exchange. Further, the height of the lower part of the perforated plate can be made structurally shorter than that of the conventional brush type cleaning device, so that the entire device can be downsized.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view of a first embodiment showing an arrangement of respective devices of a fluidized bed heat exchanger embodying the present invention.

FIG. 2 is a schematic explanatory view showing a cross section taken along the line AA of FIG.

FIG. 3 is a schematic explanatory view showing a second embodiment of the present invention.

FIG. 4 is a schematic explanatory view showing a third embodiment of the present invention.

FIG. 5 is a schematic explanatory view showing an arrangement of each device of a conventional fluidized bed heat exchanger.

6 is a schematic explanatory view showing a cross section taken along the line BB of FIG.

[Explanation of symbols]

 1 Casing 1a Exhaust Gas Inlet 1b Exhaust Gas Outlet 2 Perforated Plate 3 Solid Particle Layer 4 Heat Transfer Tube 9 High Pressure Air Discharge Pipe 9a Nozzle 11 High Pressure Air Supply Channel 12 Solenoid Valve

Claims (3)

[Claims] 1. A perforated plate 2 having a large number of ventilation holes is provided at a substantially central portion in a casing 1 having an exhaust gas inlet 1a and an exhaust gas outlet 1b, and an appropriate thickness of solid particles is provided on the perforated plate 2. In the fluidized bed heat exchanger in which the solid particle layer 3 is formed and the heat transfer tube 4 is inserted in the solid particle layer 3, a single high pressure air discharge tube 9 having a plurality of nozzles 9a at the bottom of the porous plate 2 is provided. Alternatively, a high-pressure air supply passage 11 for supplying high-pressure air is connected to the high-pressure air discharge pipe 9, and a solenoid valve 12 is provided in the high-pressure air supply passage 11, which is a fluidized bed heat exchanger. Perforated plate cleaning device. 2. The perforated plate cleaning device for a fluidized bed heat exchanger according to claim 1, wherein the high-pressure air discharge pipe 9 is rotatably provided. 3. The perforated plate cleaning device for a fluidized bed heat exchanger according to claim 1, wherein the high-pressure air discharge pipe 9 is provided slidably in the axial direction.