CN111237733A

CN111237733A - Waste heat boiler

Info

Publication number: CN111237733A
Application number: CN201910179851.XA
Authority: CN
Inventors: 竹中幸弘; 赵峰娃; 考传利; 井野辰夫; 赵米晗; 野副拓朗; 张皓; 王晓兵; 汪宁; 肖杰玉; 方伟; 刘大柱; 周健
Original assignee: Anhui Conch Kawasaki Energy Conservation Equipment Manufacturing Co Ltd; Anhui Conch Kawasaki Engineering Co Ltd; Kawasaki Jukogyo KK
Current assignee: Anhui Conch Kawasaki Energy Conservation Equipment Manufacturing Co Ltd; Anhui Conch Kawasaki Engineering Co Ltd; Kawasaki Motors Ltd
Priority date: 2015-02-12
Filing date: 2016-02-06
Publication date: 2020-06-05
Also published as: CN104696937A; CN107709879A; CN107709879B

Abstract

The invention provides a waste heat boiler which is used for recovering waste heat of exhaust gas from a PH tower of a cement pit, wherein the waste heat boiler comprises a boiler (1) and a heat conduction pipe (4) arranged in the boiler (1), the boiler (1) is provided with an inlet (2) of the exhaust gas and an outlet (3) of the exhaust gas, fins are arranged on the outer peripheral surface of the heat conduction pipe (4) in a mode that the fins are vertical to the outer peripheral surface of the heat conduction pipe (4), and the distance between the fins and the heat conduction pipe (4) in the axial direction is 15-18 mm. According to the waste heat boiler disclosed by the invention, the main heat exchange surfaces of the fins are consistent with the gravity direction of dust in the waste gas, so that the dust is difficult to accumulate among the fins, stable rotation can be realized under the condition of high-dust waste gas, and the flow direction of the waste gas is also consistent with the arrangement direction of the fins, so that the energy consumption is low.

Description

Waste heat boiler

The application is a divisional application of an invention patent application with the international application number of PCT/CN2016/073724, the international application date of 2016, 2 and 6, and the invention name of 'waste heat boiler' entering China, and the national application number of 201680010054.3.

Technical Field

The present invention relates to a boiler plant, and in particular to a waste heat boiler capable of recovering waste heat in exhaust gas.

Background

At present, waste heat boilers are widely used for recovering waste heat in waste gas generated in the production and manufacturing process in industries such as carbon black production industry, glass fiber production industry, metallurgical steel industry, petroleum industry, acid and alkali making industry, cement industry and the like.

A waste heat boiler capable of recovering waste heat in exhaust gas of a cement production kiln in the cement industry will be described as an example.

The waste heat boiler matched with the cement production kiln mainly comprises an AQC boiler (Air Quenching Coolbebler), a PH boiler (Pre heater boiler) and the like. The heat conducting performance and the energy consumption rate of the waste heat boiler mainly depend on the heat conducting pipes.

The heat conduction pipes include two types of finless heat conduction pipes (bare pipes) and finned heat conduction pipes (finned pipes).

The bare tube has smooth outer surface, fast heat conduction, small waste gas flow resistance and low energy consumption, and is widely applied to PH boilers and the like. The exhaust gas from the PH boiler was used in a bare pipe because the temperature was 300 to 400 ℃ and the dust concentration was high at about 100g/Nm3, and the dust concentration was such that the dust would not melt in the temperature range of 300 to 400 ℃ and had an extremely fine particle diameter (80% of dust having an average particle diameter of 10 μm or less) and the dust had a soft texture. If the lattice arrangement is adopted, the dust is clogged between the heat transfer pipes in the flow direction, and the heat transfer performance is lowered. In the case of the staggered arrangement, turbulence is caused when the air flow enters, so that dust clogging can be avoided, and therefore, the staggered arrangement is adopted, but dust is still extremely liable to adhere to the surface of the heat conductive pipe. Therefore, the PH boiler is usually provided with a rapping device or a soot blower to remove the dust attached to the surface of the heat conducting pipe. A rapping device adopts a mode of hammering the lower parts of heat conduction pipes which are vertically arranged. Another rapping device raps accessories fixed at the lower part of the horizontally arranged heat-conducting pipes. However, in the two rapping structures, the heat conduction pipe and the mounting fitting are fixedly connected, the heat conduction pipe and the mounting fitting cannot move relatively, the vibration is insufficient, the mounting fitting for mounting the heat conduction pipe can be impacted by the rapping device, and the durability of the waste heat boiler is weakened; in addition, in these existing rapping devices, in the case of rapping the entire bundle of heat-conducting pipes, the rapping cannot be fully performed, and the mounting fittings are susceptible to the rapping impact force; in the case where one rapping device is provided for each heat conductive pipe, the cost becomes high.

Further, although there is a sootblower as a dust removing means, the exhaust gas of the PH tower in the cement exhaust gas has a large amount of dust and high adhesion, and therefore frequent operation is required and the accounting is poor, and therefore the sootblower is not widely used.

Finned tubes are used in AQC boilers. The finned tube heat exchange area is greatly increased, and the quantity of heat conduction pipes is small, the boiler volume is greatly reduced, and the cost is reduced under the condition of obtaining the same heat exchange performance. Finned tube fins of AQC boilers are typically helical fins. The reason why the AQC boiler adopts the finned tube is that: the waste gas before entering the AQC boiler is filtered by a dust collector, the temperature of the waste gas is 300-400 ℃, the dust concentration is reduced to be below several g/Nm3, and the waste gas mainly comprises larger and harder dust with the particle size of below 200 mu m, namely the dust has the characteristic of being not easy to attach to the surface of a heat conducting pipe. For AQC boilers, the staggered arrangement is usually used without rapping devices, due to the low adherence of dust.

Compared with a bare tube and a finned tube, the bare tube has rapid heat conduction and low energy consumption, but if the heat transfer area needs to be increased, the volume or the number of the heat conduction tubes can be increased, which inevitably leads to the increase of the cost of the heat conduction tubes and even the whole boiler; the finned tubes can greatly improve the heat exchange performance, dust is easy to adhere due to the fact that the surface smoothness of the heat conduction tubes is damaged, the adhered dust is easy to block between the fins, the boiler cannot stably operate, and meanwhile the waste gas flow resistance is large and the energy consumption is high. The common design thinking at present is that a bare pipe is matched with a rapping device, a soot blower and other dust removal devices to be applied to a waste heat boiler aiming at waste gas with moderate temperature, large dust concentration, fine dust particle size and high adhesiveness; the finned tube is applied to an exhaust heat boiler aiming at waste gas with high temperature, small dust concentration, large particle size and low adhesiveness, and a rapping device, a soot blower and other dust removal devices are not required to be configured. However, under the design thinking, the existing waste heat boilers of the above types cannot economically recover the waste gas with high temperature and extremely fine adhesion of dust particle size, such as the waste gas of electric furnace for manufacturing ferrosilicon, because: the waste gas of the electric furnace for manufacturing the ferrosilicon has the temperature of 400-450 ℃, the dust concentration is low as 10g/Nm3, the particle size of the dust is extremely tiny (less than 1 mu m at 60 percent), and the adhesiveness is high. The waste gas of the electric furnace manufactured by the ferrosilicon has high temperature, if the waste heat boiler provided with the bare tube is adopted for recovery, the heat conducting area of the bare tube cannot be fully ensured economically, the waste gas still maintains high temperature after being discharged from the waste heat boiler, and the heat cannot be fully recovered; simultaneously, the dust adhesion in this ferrosilicon manufacturing electric stove's the waste gas is high, if adopt to set up the AQC exhaust-heat boiler structure of taking the finned tube to retrieve, then the dust aggravates in piling up between the heat pipe, in addition, this because do not dispose rapping device usually, so, along with the continuous adhesion of dust, will lead to exhaust-heat boiler's heat transfer performance continuously to worsen.

That is, in the various exhaust heat boilers including the PH boiler and the AQC boiler in the market, the exhaust heat of the exhaust gas having the temperature of 300 to 500 ℃, the dust concentration of 10 to 100g/Nm3, and the high dust adhesion cannot be effectively recovered. In the prior art, a waste heat boiler which combines a fin structure of a heat conduction pipe with a dust removal device, can effectively recycle various grades of waste gas with the temperature of 300-500 ℃, the dust concentration of 10-100g/Nm3 and high dust adhesion, and has high heat conduction performance and low cost does not exist.

Disclosure of Invention

The invention mainly solves the technical problem of providing the waste heat boiler, which can ensure that dust in waste gas is difficult to accumulate among fins, can realize stable rotation under the condition of high-dust waste gas and has low energy consumption.

The invention provides a waste heat boiler which is used for recovering waste heat of exhaust gas from a PH tower of a cement pit, wherein the waste heat boiler comprises a boiler (1) and a heat conduction pipe (4) arranged in the boiler (1), the boiler (1) is provided with an inlet (2) of the exhaust gas and an outlet (3) of the exhaust gas, fins are arranged on the outer peripheral surface of the heat conduction pipe (4) in a mode that the fins are vertical to the outer peripheral surface of the heat conduction pipe (4), and the distance between the fins and the heat conduction pipe (4) in the axial direction is 15-18 mm.

According to the waste heat boiler disclosed by the invention, the main heat exchange surfaces of the fins are consistent with the gravity direction of dust in the waste gas, so that the dust is difficult to accumulate among the fins, stable rotation can be realized under the condition of high-dust waste gas, and the flow direction of the waste gas is also consistent with the arrangement direction of the fins, so that the energy consumption of the waste heat boiler is low.

The invention also provides a waste heat boiler, a rapping device thereof and a heat conduction pipe installation structure, which can play a full rapping role, improve the dust removal effect, have small impact on peripheral accessories caused by the rapping force and have good equipment durability.

The invention also aims to solve another technical problem of providing the waste heat boiler, the rapping device thereof and the heat conduction pipe installation structure thereof, which have high heat conduction performance without increasing the cost and good dust removal effect and can be used for recovering waste gas of various grades.

One invention of the present application provides a waste heat boiler, which is characterized in that: the heat pipe is connected to the support member in a floating manner. Therefore, when the heat conduction pipe is hammered by the rapping device, the heat conduction pipe can move relatively to the supporting component, the rapping is sufficient, and the impact force of the rapping force on the supporting component is weakened due to the fact that the heat conduction pipe and the supporting component are not fixed together, and the durability of the equipment is good.

1) The heat conductive pipe passes through the support hole portion of the support assembly.

2) Two or more support members are arranged at intervals in the axial direction of the heat transfer pipe, and one heat transfer pipe passes through two or more support hole portions of the two or more support members.

3) The support assembly comprises a plurality of support rings corresponding to the heat conduction pipes and a support beam for fixing the support rings, and holes of the support rings form the support hole parts; or the support assembly includes a support plate having a through hole corresponding to each heat conductive pipe, the through hole constituting the support hole portion; alternatively, the support member may include a rod member having meshes corresponding to the respective heat conductive pipes, the meshes constituting the support hole portions. The support assembly of the invention has simple structure and simple and convenient installation and operation of the heat conduction pipe.

4) Fins are arranged on the surface of the heat conduction pipe.

5) The heat pipe is horizontally arranged, the fins are arranged perpendicular to the outer peripheral surface of the heat pipe and are provided to protrude radially outward along the entire peripheral surface of the outer peripheral surface, and a plurality of the fins are provided in the axial direction of the heat pipe.

6) The heat conduction pipe is vertically arranged, the fins are arranged to be perpendicular to the outer peripheral surface of the heat conduction pipe and are arranged in a protruding mode along the axis direction of the heat conduction pipe, and the fins are discontinuous in the axis direction.

The main heat exchange surface of the fin is consistent with the gravity direction of dust, the dust is not easy to attach, the main heat exchange surface of the fin is consistent with the flow direction of waste gas, and the energy consumption is low.

7) The heat conduction pipes are arranged in a grid manner; the heat conduction pipes adjacent to each other in the same horizontal plane form a heat conduction assembly, the waste heat boiler comprises a plurality of heat conduction assemblies which are arranged in parallel in the vertical direction, or the heat conduction assemblies which are arranged in parallel in the vertical plane form a heat conduction assembly, and the waste heat boiler comprises a plurality of heat conduction assemblies which are arranged in parallel in the vertical direction; the waste heat boiler comprises a plurality of rapping devices, and one rapping device corresponds to one heat-conducting component. The beam splitting vibration beating structure can play a full vibration beating role, does not burden a heat conduction pipe and installation accessories, and further improves the durability of equipment.

8) The rapping device comprises a rapping rod connected with each heat conduction assembly and a rapping assembly which is connected with each heat conduction assembly and used for rapping the rapping rod, wherein the rapping assembly comprises a rapping shaft body, a rapping hammer fixed on the rapping shaft body, and a driving motor connected with the rapping shaft body and controlling the rapping shaft body to rotate in a reciprocating manner.

9) The rapping hammer corresponds to the end or the side of the rapping rod.

10) The waste heat boiler also comprises a soot blower. When the device is used for recovering the waste gas containing small-particle-size dust with low concentration, the soot blowing device can be started.

11) The soot blowing device comprises an air source, a connecting pipe and a plurality of soot blowing pipe fittings, wherein the soot blowing pipe fittings are horizontally arranged and are positioned above the heat conduction pipes, the axes of the soot blowing pipe fittings are perpendicular to the axes of the heat conduction pipes, the soot blowing pipe fittings are connected with a push-pull rod, one end of the push-pull rod is connected with a control device capable of pushing the push-pull rod to extend or retract, and the lower part of each soot blowing pipe fitting is provided with an air jet corresponding to each heat conduction pipe. The soot blower is simple in structure, can effectively treat the adhesive dust on the heat conduction pipe with the fins to prevent the heat conduction pipe from being blocked, ensures that the heat conduction pipe has higher heat conduction performance, and improves the heat recovery efficiency of a boiler.

12) The control device includes: the boiler comprises a motor and an engaging gear connected with the motor, one end of the push-pull rod penetrates through the wall of the boiler and extends to the outside, the one end of the push-pull rod is of a screw rod structure, the engaging gear is engaged with the screw rod structure, and the rotating direction of the engaging gear is different according to the rotating direction of the motor, so that the telescopic action of the push rod is controlled.

The invention of the present application provides a waste heat boiler, comprising a boiler, a heat conducting pipe arranged in the boiler and a rapping device, wherein the boiler is provided with a waste gas inlet and a waste gas outlet, and the waste heat boiler is characterized in that: the surface of the heat conduction pipe is provided with fins, and the heat conduction pipe is connected with the supporting component in a non-fixed mode. If the finned tubes are arranged alternately, there are problems of low heat transfer efficiency and clogging due to dust accumulation. In the case of the lattice arrangement, the flow of gas can be ensured, and therefore clogging by dust does not occur. Although the accumulation of dust occurs between the heat transfer pipes in the flow direction, heat exchange can be performed on the surfaces of the fins, and therefore, the heat transfer performance of the entire exhaust heat boiler is ensured. By combining the finned tube with the installation structure of the heat conduction tube, the heat exchange performance can be greatly improved, but the cost is not increased, and the vibration effect is more sufficient, so that various grades of waste gas with the temperature of 300-500 ℃, the dust concentration of 10-100g/Nm3 and high dust adhesion can be effectively recovered.

The present invention provides a rapping device of a waste heat boiler, comprising a rapping assembly, wherein the rapping assembly comprises a rapping shaft body, a rapping hammer fixed on the rapping shaft body, and a driving motor connected with the rapping shaft body and controlling the rapping shaft body to rotate in a reciprocating manner, and the rapping device is characterized in that: the rapping device further comprises a rapping rod, the rapping rod is fixedly connected with the adjacent heat-conducting pipes, and the heat-conducting pipes are connected with the supporting component in a non-fixed mode. The beam splitting vibration beating structure can play a full vibration beating role, does not burden a heat conduction pipe and installation accessories, and improves the durability of equipment.

Another invention of the present application provides a heat pipe installation structure of a waste heat boiler, which is characterized in that: the heat pipe is connected to the support member in a floating manner. Therefore, the rapping action can be fully exerted, no load is caused on the heat conduction pipe and the mounting accessories, and the durability of the equipment is improved.

In conclusion, the waste heat boiler, the rapping device thereof and the heat conduction pipe installation structure thereof can play a full rapping role, improve the dust removal effect, have small impact of rapping force on peripheral accessories, good equipment durability and high heat conduction performance without increasing cost, can be used for recovering waste gas of various grades, can recover the waste gas of various industries, and has high universality.

Drawings

Fig. 1 is a schematic structural diagram of embodiment 1 of the present invention.

Fig. 2 to 4 are schematic views of fin structures of a heat transfer pipe according to embodiment 1 of the present invention.

Fig. 5 is a schematic view of the direction a-a of fig. 1.

Fig. 6 is a schematic view of an example of the heat pipe installation structure according to embodiment 1 of the present invention (fins are not shown).

Fig. 7 is a schematic view of another example of the heat pipe installation structure according to embodiment 1 of the present invention (fins are not shown).

Fig. 8 is a schematic view of a rapping device in accordance with embodiment 1 of the present invention.

Fig. 9 is a schematic structural view of embodiment 2 of the present invention (rapping devices, soot-blowing devices, etc. are not shown).

Fig. 10 is a schematic view of the fin structure of a heat transfer pipe according to embodiment 2 of the present invention.

Detailed Description

The following describes the exhaust-heat boiler, the rapping device and the heat pipe installation structure provided by the present invention with reference to the attached drawings. Wherein the rapping device and the heat pipe mounting structure are components of the waste heat boiler, the embodiments relating to the rapping device and the heat pipe mounting structure will be included in the embodiments of the waste heat boiler, and therefore will not be described separately. The waste heat boiler can be used as a waste heat boiler for recovering waste gas in various industries such as cement manufacturing industry, carbon black production industry, glass fiber production industry, metallurgical steel industry, petroleum industry, acid and alkali making industry and the like.

Embodiment mode 1

The invention provides a waste heat boiler, a rapping device thereof and a heat conduction pipe installation structure. The main inventive principle of the invention is that the fin structure of the heat conduction pipe with fins and the rapping device are combined to deal with high-temperature waste heat and high-adhesion dust in industrial waste gas together, thereby effectively recycling various kinds of waste gas with high dust adhesion in a dry state, for example, the temperature is 300-500 ℃, the dust concentration is 10-100g/Nm3, and the waste heat boiler has the characteristics of high heat conduction performance, low cost and effective dust removal.

As shown in fig. 1, the waste heat boiler of the present embodiment has a vertical structure, and includes a boiler 1, and an exhaust gas inlet 2 and an exhaust gas outlet 3 are provided at an upper portion and a lower portion of the boiler 1, respectively.

As an important technical feature of the present invention, a plurality of heat conduction pipes 4 with fins 23 are provided in the boiler 1, and the heat conduction pipes 4 are arranged horizontally and in a grid structure, so that dust which may be accumulated between the fins 23 is blown away during the process that the exhaust gas uniformly flows from top to bottom as shown by the arrow, thereby significantly increasing the amount of heat in the exhaust gas transferred to the heat conduction pipes 4 and improving the efficiency of heat recovery of the exhaust gas in the whole boiler. The heat conduction pipe 4 with the fins 23 is adopted, so that the heat exchange area can be effectively increased, the heat exchange performance is improved, and the cost is not increased. As shown in fig. 2 to 4, the fins 23 are provided perpendicularly to the outer peripheral surface of the heat transfer pipe 4 and project radially outward along the outer peripheral surface, and a plurality of fins 23 are provided at intervals in the longitudinal direction, i.e., the axial direction, on the outer periphery of one heat transfer pipe 4. In a preferred embodiment, as shown in fig. 2, the fins 23 are provided on the entire circumference of the outer circumference of the heat conducting pipe 4, that is, the fins 23 are closed ring-shaped fins, since the fins 23 are perpendicularly wound on the outer circumference of the heat conducting pipe 4, the main heat exchange surface of the fins 23 is aligned with the gravity direction of the dust, so that the dust is hardly accumulated between the fins 23, and the flow direction of the exhaust gas is also aligned with the arrangement direction of the fins 23, which results in low energy consumption. The closed-loop fins 23 maximize the heat exchange area, and the heat exchange area can be adjusted by changing the number and spacing of the fins 23 arranged in the longitudinal direction of the heat transfer pipe 4 and the height and thickness of the fins 23. In an alternative embodiment, as shown in fig. 3 and 4, the closed ring-shaped fins 23 may be replaced by two or more discrete fan-shaped fins, and although the heat exchange area of the fins 23 is reduced, the gaps 24 between the fan-shaped fins allow the exhaust gas to flow therethrough, which can increase the amount of heat in the exhaust gas transferred to the heat conductive pipes 4 to some extent.

Another important feature of the present invention is the mounting of the heat pipe in connection with the rapping device. As shown in fig. 1 and 5, in one embodiment of the present invention, two or more support members are arranged at intervals in the axial direction of the heat conductive pipe 4, and one heat conductive pipe 4 passes through corresponding two or more support hole portions of the two or more support members. Of course, it is also possible to provide one support member at the center in the axial direction of the heat transfer tubes 4 and then movably support the two ends of the heat transfer tubes 4 with separate supports. In the preferred embodiment, the support assembly for supporting the heat conductive pipes 4 includes a plurality of support rings 5 respectively corresponding to the heat conductive pipes 4 and a support beam 8 fixing the support rings 5. The holes of the support ring 5 constitute support hole portions. In the case where the heat conductive pipes 4 are arranged in a lattice, the support rings 5 are also arranged in a lattice. Two or more support assemblies are provided at intervals in the longitudinal direction of the heat conductive pipe 4, and one heat conductive pipe 4 passes through the corresponding support ring 5 of each group of support assemblies. In this way, the heat transfer tubes 4 are connected to the support ring 5 of the support assembly in an unfixed manner, and the gap between the outer peripheral surface of the heat transfer tubes 4 and the inner peripheral surface of the support ring 5 forms a gap enabling relative movement therebetween. Through the mounting structure of the heat conduction pipe in the embodiment, the heat conduction pipe 4 is freely installed, and under the rapping action of the rapping device, the heat conduction pipe 4 and the support ring 5 can move relatively, so that the sufficient vibration action can be performed, and the rapping impact force can not cause burden on the support assembly, so that the durability of the equipment is improved.

In another preferred embodiment, as shown in fig. 6, the support member comprises two or more support plates 51 spaced apart in the longitudinal direction of the heat transfer pipes 4, each support plate 51 is provided with a through hole 52 corresponding to each heat transfer pipe 4, one heat transfer pipe 4 passes through the corresponding through hole 52 of the plurality of support plates 51, the through hole 52 constitutes a support hole portion, and the support plates 51 are aligned with the flow direction of the exhaust gas, so that the energy consumption is low.

The above two embodiments provide the structure for movably mounting the heat conductive pipes 4 with the support ring 5 and the through holes 52. It is contemplated that in alternative embodiments, as shown in fig. 7, the heat conductive pipe 4 may be movably supported by a rod assembly 54 of metal having meshes 53, the meshes 53 constituting support hole portions, as long as the size of the meshes 53 is made larger than the size of the outer circumferential surface of the heat conductive pipe 4. Of course, the support member capable of movably supporting the heat conductive pipes 4 is not limited to the above-exemplified structure, and any structure capable of movably mounting the heat conductive pipes 4 may be adopted. In extreme cases, a metal chain can also be used to suspend the heat pipe in the boiler. Here, they are not illustrated in detail.

The inventors conducted an experiment in which the exhaust gas from the PH column of the cement pit was caused to flow through an experimental apparatus assumed to be a PH boiler. The heat transfer tubes 4 with the fins 23 had an outer diameter of phi 38mm, the heat transfer tubes 4 were arranged in a horizontal lattice, the pitch in the vertical direction perpendicular to the exhaust gas flow direction was 90mm, the pitch in the exhaust gas flow direction was 90mm, the height of the fins 23 was 21mm, and the thickness was 1.2mm, and the interior of the heat transfer tubes 4 was cooled with warm water. Here, no dust removing device was provided to confirm the dynamic of dust accumulation. The pitch of the fins 23 was changed to flow the exhaust gas, and the draft loss of the heat transfer tubes and the fouling performance of the heat transfer tubes 4 were examined to confirm the heat transfer performance. The experimental results show that: by setting the pitch of the fins 23 to 15mm or more, for example, 15 to 18mm, it is possible to obtain the dust accumulation expression (evaluated by the pressure loss in a steady state and the initial pressure loss ratio) to the same extent as in the conventional PH boiler structure (the heat transfer tubes are arranged in a vertically staggered manner with an outer diameter of a bare tube of phi 38, the pitch in the gas vertical direction is 90mm, and the pitch in the gas flow direction is 78 mm). And it was confirmed that: by optimizing the arrangement structure of the heat conduction pipes 4 and the distance between the fins 23, the accumulation amount of dust is saturated, and stable rotation under the condition of high dust exhaust gas can be realized by matching with a dust removal device.

In one embodiment, the waste heat boiler of the present invention may not be self-rapping, but may be dusted by manual rapping or by an external rapping device. In a preferred embodiment, the waste heat boiler of the present invention is a self-rapping device. The rapping device may be constructed using any rapping device known in the art. Based on the heat conduction pipe installation structure, compared with the existing heat conduction pipe installation structure, the improved rapping effect can be obtained by adopting any existing rapping device. In a preferred embodiment of the present invention, the heat conducting pipes 4 are subjected to beam splitting rapping using a specially designed rapping device of the present invention.

First, the heat conductive pipes 4 are split. In a specific splitting method, in the case where the heat transfer tubes 4 are arranged in a horizontal lattice, a plurality of heat transfer tubes 4 adjacent vertically in the same vertical plane constitute one heat transfer block 9, and in this case, as shown in fig. 1, the exhaust heat boiler includes a plurality of heat transfer blocks 9 parallel in the vertical direction. Alternatively, a plurality of heat transfer pipes 4 adjacent to each other in the same horizontal plane may constitute one heat transfer unit 9. Of course, in the case of a staggered arrangement of the heat conduction pipes 4, it is quite possible to make a plurality of heat conduction pipes adjacent to each other in a certain slope form a heat conduction assembly, and the waste heat boiler includes a plurality of heat conduction assemblies parallel to each other in the slope direction.

The rapping device of the present invention that raps against this split heat pipe will now be described.

The rapping device of the waste heat boiler comprises a rapping rod 6 connected with a heat conducting component 9 and a rapping component 7 capable of rapping the rapping rod 6. One rapping bar 6 is provided per thermally conductive assembly 9. The rapping assembly 7 comprises a rapping shaft body 10 arranged horizontally, a rapping hammer 11 fixed on the rapping shaft body 10, and a driving motor 12 which is connected with the rapping shaft body 10 and can control the rapping shaft body 10 to rotate in a reciprocating manner at a set speed. The rapping hammers 11 are arranged on the upper or lateral side of the rapping bar 6, respectively. In such a structure, each rapping hammer 11 corresponds to one rapping rod 6, and a plurality of rapping hammers 6 act in unison along with the rotation action of rapping shaft body 10, realize effectively rapping and removing dust to every heat conduction assembly 9 to can ensure to handle high concentration dust, avoid the dust to pile up in heat pipe 4 and fin 23.

It is contemplated that in one embodiment, the rapping hammer 11 may not also hammer the rapping rod 6, but may correspond to a supporting assembly, i.e., a rapping supporting assembly, such as the rapping supporting plate 51, may also achieve a better rapping effect. For waste heat boilers with limited design space, hammering the supporting plate also provides an option for designing the rapping device.

In one embodiment, not limited to the aforementioned way of splitting the heat pipes 4 according to the heat conducting assembly 9, the rapping bar 6 can be connected to any number of adjacent or non-adjacent heat pipes 4, and only the specific shape of the rapping bar 6 needs to be changed, for example, four heat pipes 4 adjacent to each other at the upper right in fig. 5 are connected to one rectangular rapping bar 6, so as to implement the split beam rapping. Here, detailed description is omitted.

Compared with the existing rapping device of the cement complete set PH boiler tower, the invention has the advantages that the whole structure of the tube bundle is knocked, and the mode of knocking each tube bundle, namely the heat conducting component 9, by the beam splitting method can obtain more sufficient rapping effect. The vibration impact force of the beam splitting vibration does not burden the heat conduction pipe 4 and installation accessories, and the durability is better.

The inventors carried out endurance experiments and vibration measurements with rapping devices of the same size as the actual object. The test of striking the rapping bar 6 connected to the heat transfer tubes 4 from above and the test of striking the rapping bar 6 laterally from the side were performed using the arrangement of the heat transfer tubes 4 and the pitch of the fins 23 mentioned in the test in which the exhaust gas from the PH tower of the cement pit was caused to flow through the test apparatus assumed to be the PH boiler. The rapping bar 6 is knocked by 3 rapping hammers (large, medium and small) with different rapping forces. Confirmed by vibration measurements: the impact force causing the damage of the device can be generated by utilizing the large rapping hammer, and the heat conduction pipe vibration larger than that of the existing PH boiler can be obtained no matter how large the rapping hammer is. In the durability test, durability against 100 ten thousand or more continuous shots was confirmed. Further, it was confirmed that by selecting an optimum rapping hammer in this configuration, a more excellent dust removal performance can be obtained and a stable operation can be performed.

In order to be able to handle low concentrations of small particle size dust, for example, the heat recovery of flue gas from ferrosilicon electric manufacturing furnaces having a dust concentration of 10g/Nm3, in a preferred embodiment of the invention, a sootblower may also be provided to remove dust as necessary in place of a rapping device. For the soot blower, a soot blower of the related art may be employed.

In the preferred embodiment of the present invention, as shown in FIGS. 1 and 5, the sootblower 13 includes a gas source 14, a connecting pipe 15, a sootblower tube 16, a push-pull rod 18, and a control device 20. The soot blowing pipe 16 is horizontally arranged and located above the heat conducting pipes 4, the axes of the soot blowing pipe 16 and the heat conducting pipes 4 are in a right-angle relationship, the soot blowing pipe 16 is connected with a horizontally arranged push-pull rod 18, one end of the push-pull rod 18 is connected with a control device 20 capable of pushing the push-pull rod 18 to extend forwards or contract backwards, and the surface below each soot blowing pipe 16 is provided with air nozzles 17 which are arranged at intervals. The angle of the air injection pipe member 16 can be adjusted.

The control part 20 includes a motor 21 and a meshing gear 22 connected to the motor 21. One end of the push-pull rod 18 penetrates through the boiler wall 19 and extends out of the boiler wall 19, the structure of the one end is a screw rod structure, the meshing gear 22 is in meshing connection with the screw rod structure, the rotating direction of the meshing gear 22 is different according to the rotating direction of the motor 21, and therefore the telescopic action of the push rod 18 is controlled. The structure is simple, and the performance is stable and reliable when the push-pull rod 18 is operated to drive the soot blowing pipe fitting 16, so that the soot blowing pipe fitting is not easy to break down. When the soot blower 13 is required to work, the control part 20 controls and pushes the push-pull rod 18 to extend forwards or contract backwards, so as to drive the soot blowing pipe 16 to move forwards and backwards, and the gas jet 17 on the soot blowing pipe 16 jets high-pressure gas from top to bottom to remove dust accumulated on the heat conduction pipe 4 and the fins 23.

The present invention achieves downward soot blowing for the interval of each heat transfer tube 4 by providing a movable soot blowing device 13 above the heat transfer tube 4. The soot blower 13 of the present invention has a simple structure, and can effectively treat the adhesive dust on the heat conduction pipe 4 with the fins 23 without blocking the heat conduction pipe, thereby ensuring the heat conduction pipe to have high heat conduction performance and improving the boiler heat recovery efficiency.

In the invention, because the rapping device and the soot blower work effectively, the fins 23 can be arranged on the heat conduction pipes 4, and the arrangement of the fins 23 effectively increases the heat conduction area, improves the heat conduction performance and effectively reduces the cost of the heat conduction pipes and the whole boiler under the condition of not increasing the volume or the number of the heat conduction pipes 4.

In order to recover the exhaust gas with high temperature or ultrahigh temperature, in a preferred embodiment, the number of the heat conducting assemblies 9, i.e. the heat conducting pipes, can be further increased, so that the heat conducting area of the heat conducting pipes in the boiler is increased, and the overall heat recovery efficiency of the waste heat boiler is improved.

Of course, in an alternative embodiment, the heat pipe installation structure of the present invention can be fully adopted, and the rapping device of the prior art can be adopted to perform rapping on the whole of the tube bundle of all the heat pipes of the waste heat boiler, so that the improved rapping effect can be obtained.

The waste heat boiler overcomes the technical prejudice that the fin structure of the heat conduction pipe and the rapping device are not combined to deal with dust in the technology of the field, and obtains the waste heat boiler which recovers waste gas containing high-adhesion dust with high temperature and ultrahigh temperature and various concentrations, has high heat conduction performance, low cost and stable operation by designing the fin structure and combining the rapping device and the soot blowing device. Horizontally arranged finned heat conductive pipes are used, and the respective heat conductive pipes 4 are arranged in parallel (lattice arrangement). To the big dust of concentration height particle size, through rapping device's rapping rod with the tip fixed connection of a certain amount of heat pipe, the uppermost or the side of rapping rod is shaken again to shake, just can realize shaking to many heat pipes and removing dust through setting up a subassembly of shaking. Dust with low concentration and small particle size, such as dust in exhaust gas of a ferrosilicon manufacturing electric furnace, is blown down into gaps between heat transfer pipes by installing a movable soot blower 13 above the heat transfer pipes. The waste heat boiler disclosed by the invention has a simple structure, and can effectively treat the adhesive dust on the finned heat conduction pipe so as not to cause blockage, thereby ensuring that the heat conduction pipe has higher heat conduction performance and improving the heat recovery efficiency of the boiler.

Embodiment mode 2

As shown in fig. 9 to 10, this embodiment is the same as embodiment 1 in principle, the installation structure of the heat transfer pipe, the structure of the rapping device and the structure of the soot blower are the same, and the heat transfer pipe splitting method is the same and will not be repeated. The differences are as follows: the exhaust-heat boiler is changed into a horizontal type, the heat conduction pipes 4 are arranged in a vertical grid, and the lower end parts of the heat conduction pipes 4 can be placed on a certain support 50.

As shown in fig. 9 to 10, in the present embodiment, the exhaust gas inlet 2 and the exhaust gas outlet 3 are provided at the left and right portions of the boiler 1, respectively. The heat conductive pipes 4 sequentially pass through a plurality of perforations 52 (not shown) as support hole portions of a plurality of support plates 51 arranged in the up-down direction. The fins 23 on the heat transfer pipes 4 are arranged perpendicular to the outer peripheral surfaces of the heat transfer pipes 4 and protrude in the axial direction of the heat transfer pipes, and in a preferred embodiment, the fins 23 are arranged in substantially the same manner as the flow of the exhaust gas indicated by the arrows, that is, the fins 23 are arranged on opposite sides of the heat transfer pipes 4 on the upstream side and the downstream side of the flow of the exhaust gas, and the fins 23 are not designed on the opposite sides of the heat transfer pipes perpendicular to the flow direction of the exhaust gas, so as to avoid energy loss. In the preferred embodiment, the fins 23 are discontinuous in the axial direction, i.e., a plurality of stages of fins 23 are provided in the longitudinal direction of the heat transfer pipes, so that the exhaust gas can pass through the gaps 24 between the respective fins 23 to increase the amount of heat transfer between the exhaust gas and the heat transfer pipes. Also, the gaps 24 between the fins 23 may serve as a site for engagement with the support assembly. Of course, fins 23 that are continuous in the axial direction may also be used.

In the present embodiment, although the heat transfer pipes 4 are arranged vertically, the surfaces of the heat transfer pipes 4 and the surfaces of the fins 23 are aligned with the direction of gravity of the dust, and the dust is less likely to adhere thereto. The rapping device can rap the upper end or the support assembly of the heat conducting pipe 4.

The present embodiment can provide the same effects as those of embodiment 1, and will not be described again here.

Embodiment 3

In addition to

embodiments

1 and 2, the exhaust-heat boiler of the present embodiment employs the same heat pipe attachment structure, rapping device, and soot blower as those of

embodiments

1 and 2. The difference is that: by replacing the finned tubes with bare tubes in

embodiments

1 and 2, excellent rapping effects can still be obtained in this embodiment, except for a reduced heat exchange performance. Therefore, the conventional PH waste heat boiler can be modified to be used for recovering waste gas with high dust adhesion and high temperature of 300-500 ℃, and the dust concentration of 10-100g/Nm 3.

Embodiment 4

In addition to

embodiments

1 and 2, the exhaust heat boiler of the present embodiment employs the same mounting structure of the heat transfer pipe as in

embodiments

1 and 2. The difference is that: the finned heat transfer pipes in

embodiments

1 and 2 are replaced with the spiral-fin heat transfer pipes in the prior art, that is, the AQC waste heat boiler in which the conventional heat transfer pipes with spiral fins are modified by using the heat transfer pipe mounting structure of the present invention. Based on the installation structure of the heat conduction pipe, the excellent rapping effect can be obtained, and the rapping device and the soot blower are combined, so that the waste gas with high dust adhesion and high dust concentration of 10-100g/Nm3 at the high temperature of 300-500 ℃ can be effectively recovered.

With respect to the prior art AQC waste heat boilers, since rapping devices are not normally included per se, it is possible in one embodiment to replace only the heat pipe mounting structure of the AQC waste heat boiler with the mounting structure of the present invention, and then to configure the rapping devices additionally.

Other modifications

The fins 23 shown in fig. 2 to 4 of embodiment 1, which are provided perpendicularly to the outer peripheral surface of the heat conductive pipe 4 and are provided convexly along the outer peripheral surface, can also be applied to a heat conductive pipe arranged vertically. Fins 23 shown in fig. 9 to 10 of embodiment 2, which are provided perpendicularly to the outer peripheral surfaces of heat conductive pipes 4 and are provided so as to project in the axial direction of heat conductive pipes 4, can also be applied to heat conductive pipes arranged horizontally. The helical fins may be applied to the heat conductive pipes arranged vertically or horizontally.

The above description is only a specific embodiment of the present invention, and should not be taken as limiting the scope of the invention, and all equivalent changes and modifications made according to the disclosure of the present invention, such as any other person utilizing the fin structure of the heat pipe of the present invention, the movable mounting structure of the heat pipe of the present invention, the structure of the beam splitting rapping using the rapping device of the present invention, and the combination of the heat pipe with fins and the rapping device, should fall within the scope of the present invention.

Claims

1. A waste heat boiler, which is a PH boiler for recovering waste heat of waste gas from a PH tower of a cement pit, wherein,

the waste heat boiler comprises a boiler (1) and a heat conduction pipe (4) arranged in the boiler (1), the boiler (1) is provided with an inlet (2) of the waste gas and an outlet (3) of the waste gas,

fins are provided on the outer peripheral surface of the heat transfer pipe (4) so as to be perpendicular to the outer peripheral surface of the heat transfer pipe (4) and so as to have a pitch in the axial direction of the heat transfer pipe (4) of 15mm to 18 mm.

2. Waste heat boiler according to claim 1,

the waste heat boiler is also provided with a rapping device (7) for rapping the heat conducting pipe (4).

3. Waste heat boiler according to claim 1,

the waste heat boiler also comprises a soot blower (13) for blowing soot on the heat conduction pipe (4).