JP6337385B1 - Heat exchanger - Google Patents

Abstract

An object of the present invention is to prevent ash accumulation on an upper tube sheet without inadvertently increasing the pressure in a heat exchanger.
An upper tube plate 8 to which one ends of a plurality of heat transfer tubes 11 are connected, an upper casing 6 forming a gas introduction chamber, and a plurality of blasters 2 for injecting gas toward the upper tube plate 8. A plurality of first blasters 21 for injecting gas toward one direction which is a radial direction of the upper tube sheet 8 or a direction inclined with respect to the radial direction, and an inclination with respect to the radial direction of the upper tube sheet 8 A plurality of blasters 2 having a plurality of second blasters 22 that inject gas in a direction different from the one direction, and a control device 5 that drives the plurality of blasters 2. The first blaster 21 and the second blaster 22 are alternately arranged in the circumferential direction C of the upper tube sheet 8, and the control device 5 includes the first blaster 21 and the second blaster 22. A heat exchanger 1 having drive units 5a that are alternately driven is provided.
[Selection] Figure 3

Description

  The present invention relates to a heat exchanger.

  The amount of domestic sewage sludge is increasing year by year, and most of it is incinerated. In the sludge incineration equipment that incinerates sludge, the exhaust gas from the combustion furnace that incinerates the sludge cake becomes high temperature, and thus heat recovery is performed to increase thermal efficiency. For example, the combustion air is preheated by exchanging heat between the exhaust gas of the incinerator and the combustion air (fluid air) of the combustion furnace with an air preheater to save energy.

As the air preheater, for example, a multi-tube heat exchanger called a shell and tube type is adopted. The multi-tube heat exchanger has a plurality of heat transfer tubes arranged in parallel with the inner cylinder inside the inner cylinder (shell).
In the heat exchanger described above, heat exchange is performed by passing high-temperature exhaust gas through the heat transfer tubes and passing combustion air between the tube plates.

  In Patent Document 1, in order to clean the heat transfer tube, a steel shot sphere is passed through the heat transfer tube, and in order to prevent ash from accumulating on the upper tube plate of the heat exchanger, gas is injected from the gas injection nozzle. A technique for spraying and blowing off ash is described.

JP 2000-171195 A

  By the way, in the above-mentioned conventional heat exchanger, when injecting gas from a plurality of gas injection nozzles to blow off ash, the pressure in the heat exchanger may be inadvertently increased and the operation of the combustion furnace may become unstable. is there.

  An object of this invention is to provide the heat exchanger which can prevent the accumulation of the ash of a tube sheet, without raising the pressure in a heat exchanger carelessly.

  According to the first aspect of the present invention, the heat exchanger includes a circular upper tube plate to which one end of a plurality of heat transfer tubes is connected, an upper casing that forms a gas introduction chamber together with the upper tube plate, A lower tube plate to which the other ends of the plurality of heat transfer tubes are connected; a lower casing that forms a gas discharge chamber together with the lower tube plate; and an inner cylinder that forms a heat exchange chamber together with the upper tube plate and the lower tube plate; A plurality of blasters disposed above the upper tube sheet in the circumferential direction of the upper tube sheet and injecting gas toward the upper tube sheet, the radial direction of the upper tube sheet or the A plurality of first blasters for injecting gas in one direction which is a direction inclined with respect to the radial direction, and a direction inclined with respect to the radial direction of the upper tube sheet, the one direction being Multiple second bras that inject gas in different different directions And a control device for driving the plurality of first blasters and the plurality of second blasters, wherein the first blaster and the second blaster are: Arranged alternately in the circumferential direction of the upper tube sheet, the control device has a drive unit that alternately drives the first blaster and the second blaster.

According to such a configuration, it is possible to prevent ash accumulation on the upper tube sheet without causing an inadvertent increase in the pressure in the heat exchanger by operating a plurality of blasters alternately instead of simultaneously. it can.
In addition, by arranging two types of blasters, a first blaster that injects gas in one direction and a second blaster that injects gas in the other direction, on the upper tube sheet You can spray gas to more range of.

  In the heat exchanger, the control device may drive the first blaster and the second blaster one by one along the circumferential direction of the upper tube sheet.

  According to such a configuration, it is possible to reliably prevent an increase in pressure in the heat exchanger by driving the blasters one by one.

  According to the second aspect of the present invention, the heat exchanger includes a circular upper tube plate to which one end of a plurality of heat transfer tubes is connected, an upper casing that forms a gas introduction chamber together with the upper tube plate, A lower tube plate to which the other ends of the plurality of heat transfer tubes are connected; a lower casing that forms a gas discharge chamber together with the lower tube plate; and an inner cylinder that forms a heat exchange chamber together with the upper tube plate and the lower tube plate; A plurality of blasters disposed above the upper tube sheet in the circumferential direction of the upper tube sheet and injecting gas toward the upper tube sheet, the radial direction of the upper tube sheet or the A plurality of first blasters for injecting gas in one direction which is a direction inclined with respect to the radial direction, and a direction inclined with respect to the radial direction of the upper tube sheet, the one direction being Multiple second bras that inject gas in different different directions And a control device for driving the plurality of first blasters and the plurality of second blasters, wherein the first blaster and the second blaster are: The controller is arranged symmetrically with respect to the center point of the upper tube sheet, or symmetrical with respect to a straight line including the center point of the upper tube sheet, and the control device includes the first blaster and the second blaster. Are alternately driven.

  The heat exchanger further includes a first pressure accumulation tank that supplies the gas to the first blaster, and a second pressure accumulation tank that supplies the gas to the second blaster. The pressure accumulation tank may supply the gas to at least two of the first blasters, and the second pressure accumulation tank may supply the gas to at least two of the second blasters.

According to such a configuration, the first blaster and the second accumulator tank that supply gas to the second blaster are different from each other. Therefore, after the first blaster is driven, the second blaster is not interrupted. Can be driven.
In addition, since one accumulator tank is shared by two blasters, it is possible to reduce costs and save space.

  The said heat exchanger WHEREIN: The jet outlet of said 1st blaster and said 2nd blaster may be a substantially rectangular shape in which a long axis follows a horizontal axis in a horizontal direction, or a substantially rectangular shape in which a long side extends in a horizontal direction.

  According to such a configuration, the gas ejected from the ejection port can be expanded in the horizontal direction.

  In the heat exchanger, it has a thermography capable of measuring the heat distribution of the upper surface of the upper tube sheet, the control device has an analysis unit for analyzing an image photographed by the thermography, the drive unit, The first blaster and the second blaster may be driven when the analyzing unit determines that the through hole of the upper tube sheet is closed.

  According to such a configuration, by monitoring the state of the upper tube sheet using thermography, it is possible to prevent the through-hole of the tube sheet from proceeding and exceeding the allowable range that can be blown away by the blaster.

According to the present invention, it is possible to prevent ash accumulation on the upper tube sheet without causing an inadvertent increase in the pressure in the heat exchanger by operating a plurality of blasters alternately instead of simultaneously.
In addition, by arranging two types of blasters, a first blaster that injects gas in one direction and a second blaster that injects gas in the other direction, on the upper tube sheet You can spray gas to more range of.

It is a block diagram of a sewage treatment plant provided with the heat exchanger of embodiment of this invention. It is sectional drawing seen from the side of the heat exchanger of embodiment of this invention. It is sectional drawing seen from the upper direction of the heat exchanger of embodiment of this invention. It is the figure which looked at the blaster of embodiment of this invention from the side. It is the figure which looked at the blaster of the embodiment of the present invention from the upper part. FIG. 6 is a view taken in the direction of arrow VI of FIG. It is a figure explaining the effect | action of the blaster of embodiment of this invention.

A heat exchanger according to an embodiment of the present invention will be described in detail with reference to the drawings.
First, the sewage treatment plant 50 provided with the heat exchanger 1 of the present embodiment will be described. The sewage treatment plant 50 includes a wastewater treatment unit 51 and a sludge treatment unit 52 that treats sludge separated from the wastewater. The waste water treatment unit 51 treats organic waste water containing nitrogen, phosphorus or organic substances such as sewage sludge and factory waste water.

The wastewater treatment unit 51 includes a pretreatment facility 53 into which the wastewater W is introduced, a first sedimentation basin 54 that separates the sludge P from the wastewater W that has been treated by the pretreatment facility 53, and sludge P in the first sedimentation basin 54. An advanced treatment facility 55 that performs advanced treatment on the separated wastewater W, and a final sedimentation basin 56 that further separates sludge P from the wastewater W that has been subjected to advanced treatment.
In the wastewater treatment unit 51, sludge P is generated by solid separation in the first sedimentation basin 54 at the front stage of the advanced treatment facility 55 and the final sedimentation basin 56 at the rear stage of the advanced treatment facility 55. The drainage W is discharged into the river through the above facilities.

  The pretreatment facility 53 is a facility for removing impurities contained in the introduced waste water W. Examples of the pretreatment facility 53 include a crushing unit that crushes large-diameter sludge and a separation unit such as a screen that can remove impurities.

  The first sedimentation basin 54 is a sludge separation facility that separates fine sludge P contained in the waste water W by sinking it to the bottom. A first sludge line 57 is connected to the bottom of the first sedimentation basin 54. The sludge P first separated in the sedimentation basin 54 is introduced into the first sludge line 57.

  The advanced treatment facility 55 has a configuration in which an anaerobic tank that performs anaerobic treatment such as methane fermentation, an aerobic tank that performs aeration, and a sedimentation tank, and mainly by the action of nitrifying bacteria and denitrifying bacteria. This equipment decomposes and removes nitrogen and phosphorus in the liquid. By removing phosphorus from the waste water W by the advanced treatment facility 55, the phosphorus content of the sludge P is increased. That is, the sludge P processed in the sludge processing unit 52 is sludge containing phosphorus at a high content rate.

  In the final sedimentation basin 56, the sludge P including the organisms used for treatment in the advanced treatment facility 55 accumulates at the bottom. A second sludge line 58 is connected to the bottom of the final sedimentation basin 56. The sludge P separated in the final sedimentation basin 56 is introduced into the second sludge line 58.

  The sludge treatment unit 52 includes a sludge storage tank 59 provided on the downstream side of the first sludge line 57 and the second sludge line 58, a sludge dewatering machine 60 provided on the downstream side of the sludge storage tank 59, and sludge. A sludge dryer 61 provided on the downstream side of the dehydrator 60 and a sludge incineration facility 62 that incinerates the dried sludge discharged from the sludge dryer 61 are provided.

The sludge dewatering device 60 is a device for dewatering the sludge P sent from the sludge storage tank 59. As the sludge dehydrator 60, a centrifugal separator or a screw press type dehydrator can be employed.
The sludge dryer 61 is a device that dries the dewatered sludge that has been dewatered by the sludge dewaterer 60. As the sludge dryer 61, a disk dryer can be adopted.

The sludge incineration facility 62 includes an incinerator 63 that incinerates sludge P (dry sludge) and discharges exhaust gas EG, a heat exchanger 1 that heats (preheats) combustion air A supplied to the incinerator 63, and exhaust gas. It has an exhaust gas duct 64 into which EG is introduced, and an air duct 65 that supplies combustion air A to the incinerator 63.
The heat exchanger 1 performs heat exchange between the exhaust gas EG that is a high-temperature fluid and the combustion air A that is a low-temperature fluid that is lower in temperature than the exhaust gas EG.

The exhaust gas duct 64 has a first exhaust gas duct 64 </ b> A that connects the incinerator 63 and the heat exchanger 1 so that the exhaust gas EG discharged from the incinerator 63 is supplied to the heat exchanger 1. A second exhaust gas duct 64B that sends the exhaust gas EG to a subsequent device such as a chimney 66.
The air duct 65 exchanges heat with the incinerator 63 so that the combustion air A is introduced into the heat exchanger 1 and the combustion air A whose temperature has been raised by heat exchange is supplied to the incinerator 63. And a second air duct 65 </ b> B that connects the vessel 1.

  Since the combustion air A to be supplied to the incinerator 63 is warmed by the heat exchanger 1, the incinerator 63 can easily incinerate an incineration object that is difficult to burn, such as sewage sludge. That is, the heat exchanger 1 of this embodiment preferably functions as an air preheater for preheating the combustion air A supplied to the incinerator 63 for sludge incineration.

As shown in FIG. 2, the heat exchanger 1 is a multi-tube heat exchanger called a shell and tube type. The heat exchanger 1 accommodates a plurality of heat transfer tubes 11 inside the inner cylinder 10, and performs heat exchange by flowing fluids having different temperatures inside and outside the heat transfer tubes 11.
The heat exchanger 1 includes a circular upper tube plate 8 to which one ends of a plurality of heat transfer tubes 11 are connected, an upper casing 6 that forms a gas introduction chamber 6 a together with the upper tube plate 8, and a plurality of heat transfer tubes 11. A lower tube plate 9 having an end connected thereto, a lower casing 7 that forms a gas discharge chamber 7a together with the lower tube plate 9, an inner cylinder 10 that forms a heat exchange chamber 10a together with the upper tube plate 8 and the lower tube plate 9, It has.

A first exhaust gas duct 64A is connected to the gas introduction chamber 6a, and exhaust gas EG discharged from the incinerator 63 (see FIG. 1) is introduced. The gas introduction chamber 6 a is formed by a circular upper tube sheet 8 and an upper casing 6. One end of a plurality of heat transfer tubes 11 is connected to the upper tube sheet 8.
A plurality of through holes 12 for inserting the heat transfer tubes 11 are formed in the upper tube sheet 8. The heat transfer tube 11 is positioned at a predetermined position by being inserted through the through hole 12.

  As the exhaust gas EG flows into the heat transfer tube 11 from the gas introduction chamber 6a, ash accumulates on the upper tube sheet 8. The heat exchanger 1 has eight blasters 2 (gas injection nozzles) for injecting a gas (for example, air, but a gas other than air) toward the upper tube plate 8 and blowing off the ash on the upper tube plate 8. 2 shows only two), four accumulator tanks 3 (only two are shown in FIG. 2) for supplying gas to the blaster 2, and a control device 5.

A second exhaust gas duct 64B is connected to the gas discharge chamber 7a, and the exhaust gas EG that has finished heat exchange is introduced. The gas discharge chamber 7 a is formed by a circular lower tube sheet 9 and a lower casing 7. The other end of the plurality of heat transfer tubes 11 is connected to the lower tube sheet 9.
The heat exchange chamber 10 a is formed by a cylindrical inner cylinder 10. The plurality of heat transfer tubes 11 are arranged inside the inner cylinder 10.

The plurality of heat transfer tubes 11 extend vertically in the heat exchange chamber 10a and connect the gas introduction chamber 6a and the gas discharge chamber 7a.
The exhaust gas EG is introduced from the incinerator 63 into the gas introduction chamber 6a through the first exhaust gas duct 64A. The exhaust gas EG flows from the gas introduction chamber 6a through the plurality of heat transfer tubes 11 to the gas discharge chamber 7a. The exhaust gas EG is sent from the gas discharge chamber 7a through the second exhaust gas duct 64B to the subsequent equipment and is finally released to the atmosphere.

The first air duct 65 </ b> A is connected to an air inlet 13 provided at the upper part of the inner cylinder 10. The second air duct 65 </ b> B is connected to the air outlet 14 provided at the lower part of the inner cylinder 10.
Combustion air A flowing through the first air duct 65A flows into the heat exchange chamber 10a from the air inlet 13, flows through the heat exchange chamber 10a, and then passes through the air outlet 14 and the second air duct 65B to the incinerator. 63. Heat exchange is performed between the exhaust gas EG flowing through the heat transfer tube 11 and the combustion air A flowing through the heat exchange chamber 10 a via the wall surface of the heat transfer tube 11.
A baffle plate 17 is provided in the heat exchange chamber 10a so that the air flow in the heat exchange chamber 10a strikes the heat transfer tubes 11 as equally as possible.

Each blaster 2 is fixed to the upper casing 6. Each pressure accumulation tank 3 is fixed to the outside of the lower casing 7. The location where the blaster 2 and the pressure accumulating tank 3 are fixed is not limited to this, but the position of the pressure accumulating tank 3 closer to the blaster 2 is preferable because the pressure loss due to piping is reduced. For example, each pressure accumulation tank may be fixed to the outside of the upper casing 6.
The blaster 2 and the pressure accumulation tank 3 are connected by a gas supply line 4. The gas supply line 4 is provided with a valve 15 for controlling the gas flowing through the gas supply line 4. Each pressure accumulating tank 3 is connected to two blasters 2. That is, one accumulator tank 3 supplies gas to the two blasters 2.

  As shown in FIG. 3, the heat transfer tubes 11 are arranged at equal intervals and in a staggered pattern (staggered arrangement). In the staggered pattern, the heat transfer tubes 11 are arranged in a row at intervals from the adjacent heat transfer tubes 11, and the heat transfer tubes 11 forming one row form a row adjacent to this row. It is arranged so that it may be located between.

The heat exchanger 1 of the present embodiment has eight blasters 2. The eight blasters 2 are arranged at equal intervals in the circumferential direction.
As shown in FIG. 4, each blaster 2 has a main body portion 23 that penetrates through the upper casing 6 and a front end that is connected to the front end of the main body portion 23 and disposed inside the upper casing 6 (the gas introduction chamber 6 a). Part 24. As shown in FIG. 3, the main body 23 of the blaster 2 extends along the radial direction of the upper tube sheet 8.
The distal end portion 24 has a spout 25. The eight blasters 2 are arranged so that each of the jet outlets 25 has a circular shape when viewed from above.

The main body 23 is fixed to the upper casing 6. The base end of the main body 23 is outside the upper casing 6, and the tip of the main body 23 is inside the upper casing 6.
The tip portion 24 is inclined so as to become lower from the connecting portion with the main body portion 23 toward the tip. That is, the tip portion 24 is inclined so that the introduced gas is injected toward the upper tube sheet 8. The jet outlet 25 is provided at the tip of the tip portion 24. The blaster 2 is arranged so that the jet outlet 25 is located above the upper tube plate 8 and in the vicinity of the outer peripheral portion of the upper tube plate 8.

The heat exchanger 1 of the present embodiment includes four first blasters 21 that inject gas toward the center portion of the upper tube sheet 8 and four first blasters 21 that inject gas toward the outer periphery of the upper tube sheet 8. Two blasters 22. The first blaster 21 and the second blaster 22 have different angles with respect to the radial direction of the distal end portion 24 (the radial direction of the upper tube sheet 8).
The first blaster 21 and the second blaster 22 are alternately arranged in the circumferential direction C of the upper tube sheet 8. That is, the blaster 2 adjacent in the circumferential direction C of the first blaster 21 is the second blaster 22.

  The heat exchanger 1 of the present embodiment has four pressure accumulating tanks 3. Specifically, the heat exchanger 1 includes two first pressure accumulation tanks 31 that supply gas to the first blaster 21, two second pressure accumulation tanks 32 that supply gas to the second blaster 22, have.

  The first pressure accumulation tank 31 supplies gas to the two first blasters 21. The first pressure accumulation tank 31 has two gas supply lines 4, and each gas supply line 4 is connected to the first blaster 21. Each gas supply line 4 is provided with a valve 15 for flowing or stopping the gas flowing through the gas supply line 4.

  The second pressure accumulation tank 32 supplies gas to the two second blasters 22. The second accumulator tank 32 has two gas supply lines 4, and each gas supply line 4 is connected to the second blaster 22. Each gas supply line 4 is provided with a valve 15 for flowing or stopping the gas flowing through the gas supply line 4.

  The control device 5 is electrically connected to a valve 15 provided in a gas supply line 4 that connects the accumulator tank 3 and the blaster 2. The control device 5 includes a drive unit 5 a that controls the eight valves 15 corresponding to the eight blasters 2. When the drive unit 5a of the control device 5 performs control to open and close the valve 15, the blaster 2 is driven to inject gas. The drive unit 5 a is set to drive the eight blasters 2 one by one along the circumferential direction of the upper tube sheet 8.

Next, the detailed shapes of the first blaster 21 and the second blaster 22 will be described.
The distal end portion 24 (see FIG. 4) of the first blaster 21 is directed to inject gas toward the radial direction of the upper tube sheet 8. In other words, the first blaster 21 is formed such that the central axis of the tip 24 of the first blaster 21 is along the radial direction of the upper tube sheet 8 when viewed from above.

  As shown in FIG. 5, the distal end portion 24 of the second blaster 22 is directed so as to inject gas in a direction inclined with respect to the radial direction R of the upper tube sheet 8. The second blaster 22 is formed so that the central axis A of the distal end portion 24 of the second blaster 22 is along the direction inclined with respect to the radial direction R of the upper tube sheet 8 when viewed from above. The four second blasters 22 have tip portions 24 inclined to one side in the circumferential direction C of the upper tube sheet 8. Specifically, the central axis A of the distal end portion 24 of the second blaster 22 is inclined by 45 ° with respect to the radial direction R of the upper tube sheet 8 when viewed from above.

As shown in FIG. 6, the jet outlet 25 of the second blaster 22 has a substantially elliptical shape with the major axis extending in the horizontal direction H when viewed from the axial direction of the tip end portion 24. Whereas the cross-sectional shapes of the main body portion 23 and the tip portion 24 are circular, the spout 25 has a shape with a narrow vertical width and a wide horizontal width. The shape of the ejection port 25 is not limited to a substantially elliptical shape, and may be a substantially rectangular shape whose long side extends along the horizontal direction H, for example.
Further, the jet outlet 25 of the first blaster 21 has a similar shape.

  As shown in FIG. 2, the heat exchanger 1 includes a thermography (for example, an infrared camera) 18 capable of measuring the heat distribution of the upper tube sheet 8. The thermography 18 analyzes the infrared rays emitted from the upper tube sheet 8 and measures the heat distribution of the upper tube sheet 8. The thermography 18 has a function of creating an image representing the heat distribution of the upper tube sheet 8. The thermography 18 images the upper tube sheet 8 through an observation window 19 formed in the upper casing 6.

  The thermography 18 is electrically connected to the control device 5. The control device 5 includes an analysis unit 5 b that analyzes an image photographed by the thermography 18. Based on the image representing the heat distribution, the analysis unit 5b determines whether or not the through hole 12 of the upper tube sheet 8 is being blocked by ash. The drive unit 5a of the control device 5 drives the first blaster 21 and the second blaster 22 when it is determined by the analysis unit 5b that the through hole 12 of the upper tube sheet 8 is closed.

  The analysis part 5b memorize | stores the image showing the heat distribution of the upper tube sheet 8 at the time of normal, and the image showing the heat distribution of the upper tube sheet 8 at the time of obstruction | occlusion (or when obstruction | occlusion is progressing). doing. Based on these images, the analysis unit 5b determines whether or not the through hole 12 of the upper tube sheet 8 is being closed.

Next, the control method of the blaster 2 of the heat exchanger 1 of this embodiment is demonstrated.
The control method of the blaster 2 of the heat exchanger 1 includes a monitoring process of monitoring the upper tube sheet 8 of the heat exchanger 1 and a driving process of driving the blaster 2 according to the situation of the upper tube sheet 8. Yes.
In the monitoring process, the analysis unit 5b of the control device 5 determines whether or not the through hole 12 of the upper tube sheet 8 is being closed. When the analysis unit 5b determines that the through-hole 12 of the upper tube sheet 8 is closed, the drive unit 5a of the control device 5 performs a drive process.

In the driving process, the driving unit 5a of the control device 5 operates the blasters 2 one by one. The drive unit 5a of the control device 5 opens and closes the valve 15a to drive the first blaster 21a disposed at the 12 o'clock position in FIG. 3, and then rotates in the circumferential direction (for example, clockwise) of the upper tube sheet 8. The valve 15 is opened and closed so that the blasters 2 are driven one by one.
Since the first blaster 21 and the second blaster 22 are alternately arranged in the circumferential direction, the first blaster 21 and the second blaster 22 are driven alternately. Specifically, the valve 15 corresponding to the one blaster 2 is opened, the gas is injected into the upper tube plate 8, the valve 15 is closed, and then the valve corresponding to the second blaster 2 adjacent to the one blaster 2. After opening 15, the control of closing the valve 15 is repeated.

The operation of sequentially opening and closing the eight blasters 2 one by one is defined as one cycle, and the control device 5 may determine whether or not to execute a plurality of cycles based on the image obtained by the thermography 18.
As shown in FIG. 7, the distal end portion 24 of the first blaster 21 faces the radial direction of the upper tube sheet 8, and the distal end portion 24 of the second blaster 22 faces the direction inclined with respect to the radial direction. Thus, the overlap between the gas range R1 injected from the first blaster 21 and the gas range R2 injected from the second blaster 22 is reduced. Further, the gas injected from the second blaster 22 is injected to the outer peripheral portion of the upper tube sheet 8.

According to the above embodiment, the pressure in the heat exchanger 1 is inadvertently increased by operating the first blaster 21 and the second blaster 22 alternately instead of simultaneously operating the plurality of blasters 2. In addition, ash accumulation on the upper tube sheet 8 can be prevented. Thereby, the operation of the incinerator 63 can be stably performed.
Further, two types of blasters 2 are provided: a first blaster 21 for injecting gas toward the radial direction of the upper tube sheet 8 and a second blaster 22 for injecting gas toward a direction inclined with respect to the radial direction. By arranging them alternately, gas can be blown to a larger area on the upper tube sheet 8.

Further, by driving the blasters 2 one by one, it is possible to reliably prevent an increase in pressure in the heat exchanger 1.
Further, since the pressure accumulating tank 3 for supplying gas to the first blaster 21 and the pressure accumulating tank 3 for supplying gas to the second blaster 22 are different, the first blaster 21 is driven immediately after the first blaster 21 is driven. The second blaster 22 can be driven. That is, when the adjacent blasters 2 are sequentially driven by using one pressure accumulating tank 3, it takes time to charge the pressure accumulating tank 3, so that when the first blaster 21 is driven, the second blaster 22 is moved. Although it may be impossible to drive immediately, such a situation can be prevented.
Further, since one accumulator tank 3 is shared by the two blasters 2, it is possible to reduce costs and save space.

  In addition, since the ejection port 25 has a shape that is long in the horizontal direction, the gas ejected from the ejection port 25 can be expanded in the horizontal direction. Thereby, gas can be sprayed on a wider range.

  Further, by monitoring the state of the upper tube sheet 8 using the thermography 18, when the blockage of the through hole 12 of the upper tube sheet 8 is slightly advanced, that is, in the initial state of the blockage, the blaster 2 is immediately driven to remove the ash. As a result, it is possible to prevent the passage of the through-hole 12 of the upper tube plate 8 from proceeding and, as a result, to prevent the passage of the heat transfer tube from proceeding, so that the heat transfer tube can be fundamentally prevented from being blocked. In particular, when the sludge P contains a high amount of phosphorus, accumulation of ash may progress suddenly, so monitoring of the thermography 18 can reliably prevent the through-hole 12 from being blocked by ash. Can do.

  In addition, in the heat exchanger 1 of the said embodiment, it is set as the structure which the 1st blaster 21 injects gas toward radial direction, and the 2nd blaster 22 injects gas in the direction inclined with respect to radial direction. However, it is not limited to this. For example, the first blaster 21 injects gas toward one direction inclined with respect to the radial direction, and the second blaster 22 is inclined with respect to the radial direction, which is different from the one direction. It is good also as a structure which injects gas toward this direction. That is, it is only necessary that the first blaster 21 and the second blaster 22 have different inclination angles with respect to the radial direction.

  Moreover, in the heat exchanger 1 of the said embodiment, although the 1st blaster 21 and the 2nd blaster 22 are alternately arrange | positioned in the circumferential direction of the upper tube sheet 8, it is not restricted to this. For example, the first blaster 21 and the second blaster 22 may be arranged point-symmetrically with respect to the center point of the upper tube sheet 8. Further, the first blaster 21 and the second blaster 22 may be arranged symmetrically with respect to a straight line including the center point of the upper tube sheet 8.

Moreover, in the said embodiment, although the number of blasters 2 was eight, it is not restricted to this, It can change suitably according to the magnitude | size etc. of the upper tube sheet 8. FIG.
In the above embodiment, the blaster 2 is driven one by one. However, the first blaster 21 and the second blaster 22 may be driven alternately. For example, two blasters 21 and The two second blasters 22 may be driven alternately.
Moreover, in the said embodiment, it was set as the structure which injects gas in the direction inclined with respect to radial direction by inclining the front-end | tip part 24 of the 2nd blaster 22 with respect to the main-body part 23, but the 1st blaster The blaster 2 having the same shape as 21 may be arranged so as to be inclined with respect to the radial direction.

(Modification)
In the above embodiment, the pressure of the gas supplied from the pressure accumulating tank 3 is constant, but the pressure may be different. For example, the pressure of the gas supplied from the second pressure storage tank 32 may be lower than the pressure of the gas supplied from the first pressure storage tank 31.
For example, when more ash is accumulated at the center of the upper tube sheet 8, the ash at the center of the upper tube sheet 8 is given priority by increasing the pressure of the gas injected from the first blaster 21. Can be blown away.
Further, the pressure may be changed depending on the timing, for example, by lowering the pressure of the gas injected later in one cycle.

The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and includes design changes and the like within a scope not departing from the gist of the present invention. .
For example, the heat exchanger 1 may be applied to other types of incineration facilities or to facilities other than the incineration facilities.

DESCRIPTION OF SYMBOLS 1 Heat exchanger 2 Blaster 3 Accumulation tank 4 Gas supply line 5 Control apparatus 5a Drive part 5b Analysis part 6 Upper casing 6a Gas introduction chamber 7 Lower casing 7a Gas discharge chamber 8 Upper tube sheet 9 Lower tube sheet 10 Inner cylinder 10a Heat exchange Chamber 11 Heat transfer tube 12 Through hole 13 Air inlet 14 Air outlet 15 Valve 17 Baffle plate 18 Thermography (infrared camera)
DESCRIPTION OF SYMBOLS 19 Observation window 21 1st blaster 22 2nd blaster 23 Main-body part 24 Front-end | tip part 25 Outlet 31 1st pressure accumulation tank 32 2nd pressure accumulation tank 50 Sewage treatment plant 51 Wastewater treatment part 52 Sludge treatment part 53 Pretreatment equipment 54 First sedimentation basin 55 Advanced treatment facility 56 Final sedimentation basin 59 Sludge storage tank 60 Sludge dehydrator 61 Sludge dryer 62 Sludge incineration facility 63 Incinerator 64 Exhaust gas duct 65 Air duct 66 Chimney A Combustion air EG Exhaust gas P Sludge W Wastewater

Claims (6)

A circular upper tube plate to which one end of a plurality of heat transfer tubes is connected;
An upper casing forming a gas introduction chamber together with the upper tube sheet;
A lower tube plate to which the other ends of the plurality of heat transfer tubes are connected;
A lower casing forming a gas discharge chamber together with the lower tube sheet;
An inner cylinder that forms a heat exchange chamber together with the upper tube sheet and the lower tube sheet;
A plurality of blasters that are arranged above the upper tube sheet at intervals in the circumferential direction of the upper tube sheet, and inject gas toward the upper tube sheet,
A plurality of first blasters for injecting gas toward one direction which is a radial direction of the upper tube sheet or a direction inclined with respect to the radial direction;
A plurality of blasters having a plurality of second blasters that are directions inclined with respect to the radial direction of the upper tube sheet and inject gas toward another direction different from the one direction;
A control device for driving the plurality of first blasters and the plurality of second blasters;
The first blaster and the second blaster are alternately arranged in the circumferential direction of the upper tube sheet,
The control device is a heat exchanger having a drive unit that alternately drives the first blaster and the second blaster.   2. The heat exchanger according to claim 1, wherein the control device drives the first blaster and the second blaster one by one along a circumferential direction of the upper tube sheet. A circular upper tube plate to which one end of a plurality of heat transfer tubes is connected;
An upper casing forming a gas introduction chamber together with the upper tube sheet;
A lower tube plate to which the other ends of the plurality of heat transfer tubes are connected;
A lower casing forming a gas discharge chamber together with the lower tube sheet;
An inner cylinder that forms a heat exchange chamber together with the upper tube sheet and the lower tube sheet;
A plurality of blasters that are arranged above the upper tube sheet at intervals in the circumferential direction of the upper tube sheet, and inject gas toward the upper tube sheet,
A plurality of first blasters for injecting gas toward one direction which is a radial direction of the upper tube sheet or a direction inclined with respect to the radial direction;
A plurality of blasters having a plurality of second blasters that are directions inclined with respect to the radial direction of the upper tube sheet and inject gas toward another direction different from the one direction;
A control device for driving the plurality of first blasters and the plurality of second blasters;
The first blaster and the second blaster are arranged symmetrically with respect to a center point of the upper tube sheet, or symmetrical with respect to a straight line including the center point of the upper tube sheet,
The control device is a heat exchanger having a drive unit that alternately drives the first blaster and the second blaster. A first pressure accumulation tank for supplying the gas to the first blaster;
A second accumulator tank for supplying the gas to the second blaster,
The first pressure accumulation tank supplies the gas to at least two of the first blasters, and the second pressure accumulation tank supplies the gas to at least two of the second blasters. Item 4. The heat exchanger according to any one of items 3.   The spout of the first blaster and the second blaster has a substantially elliptical shape with a long axis in the horizontal direction or a substantially rectangular shape with a long side in the horizontal direction. The heat exchanger according to item. A thermography capable of measuring the heat distribution on the upper surface of the upper tube sheet;
The control device has an analysis unit that analyzes an image photographed by the thermography,
The said drive part drives said 1st blaster and said 2nd blaster, when it is judged by the said analysis part that obstruction | occlusion of the through-hole of the said upper tube sheet is advancing. The heat exchanger as described in any one of.

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