Waste heat recovery system for waste heat boiler and side-blown converter

Abstract

The utility model discloses a waste heat boiler and a waste heat recovery system of a side blowing furnace, the waste heat boiler comprises a furnace body, a turning smoke chamber, a centralized downcomer and a plurality of vertical-rising flues are arranged in the furnace body in parallel along the height direction, a gathering header and a boiler barrel communicated with the gathering header are arranged at the top of the furnace body, and a dispersed downcomer is arranged at the bottom of the furnace body; a smoke outlet is formed in the side wall of the turning smoke chamber, smoke inlets are formed in the bottoms of the multiple vertical-lifting flues, and the tops of the multiple vertical-lifting flues communicate with the top of the turning smoke chamber; the side walls of the turning smoke chamber and the vertical lifting flue are membrane water-cooled walls, upper headers are arranged at the tops of the membrane water-cooled walls, and lower headers are arranged at the bottoms of the membrane water-cooled walls; the upper header is communicated with the gathering header, the boiler barrel is communicated with the top of the centralized downcomer, the bottom of the centralized downcomer is communicated with the dispersed downcomer, and the dispersed downcomer is communicated with the lower header. The waste heat boiler solves the technical problems that in the prior art, a waste heat boiler is low in heat exchange efficiency and high in construction cost.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of waste heat boiler, concretely relates to a waste heat boiler and side blowing furnace waste heat recovery system. BACKGROUND

[0002] The side blowing furnace has been widely applied in non-ferrous industry such as regenerative lead, lead-zinc smelting, copper smelting, etc., in order to handle the high-temperature flue gas discharged by the side blowing furnace, a waste heat boiler is generally configured at the flue gas outlet of the side blowing furnace for recycling the heat in the flue gas. The flue gas temperature at the outlet of the side blowing furnace is generally 1100-1300 DEG C, and is about 350 DEG C after being cooled by the waste heat boiler. At present, two side blowing furnaces are equipped with two continuous furnaces process, and one set of waste heat boiler is equipped for each of the two side blowing furnaces to recycle the waste heat in the flue gas. The two sets of waste heat boilers have large floor area, and the construction cost and construction period are long. When the flue gas condition of one side blowing furnace is unstable, it is not conducive to the stable work of the subsequent flue gas treatment equipment.

[0003] Chinese patent CN206073033U discloses a double-channel waste heat boiler, which comprises a weighing framework and a waste heat boiler. The waste heat boiler is in vertical I-shaped structure and is arranged on the weighing framework. A partition plate is arranged in the flue of the waste heat boiler, and the partition plate divides the flue into left and right two flues which are independent of each other. One end of each of the left and right flues is communicated with the left and right flue gas input ports, and the other end is communicated with the left and right flue gas output ports. The left and right flues are provided with waste heat boiler heat transfer surfaces which are independent of each other and do not interfere with each other. The left and right flue gas input ports, the smoke pipe type evaporator, the economizer and the left and right flue gas output ports are sequentially arranged on the upper end of the weighing framework from top to bottom according to the flue gas flow direction. A steam drum is arranged above the left and right flue gas input ports, and the steam drum is connected with the smoke pipe type evaporator and the economizer through a pipe system. The smoke pipe type evaporator and the steam drum constitute a water-steam circulation loop through the ascending pipe and the descending pipe. The double-channel waste heat boiler is provided with two independent flues and heat exchange equipment to exchange heat with the flue gas respectively, and the heat exchange efficiency is low and the construction cost is high. UTILITY MODEL CONTENTS

[0004] In view of the existing technical problems, the utility model aims at providing a waste heat boiler and side blowing furnace waste heat recovery system, which can solve the technical problems of low heat exchange efficiency and high construction cost of the waste heat boiler in the prior art.

[0005] In order to achieve the above-mentioned purpose, the utility model adopts the following technical scheme:

[0006] The waste heat boiler comprises a furnace body, and is characterized in that: a turning smoke chamber, a concentrated descending pipe and a plurality of straight rising flues are arranged in parallel along the height direction in the furnace body; a collection header and a drum connected with the collection header are arranged at the top of the furnace body; and a dispersion descending pipe is arranged at the bottom of the furnace body; a smoke gas outlet is arranged on the side wall of the turning smoke chamber; a smoke gas inlet is arranged at the bottom of each of the plurality of straight rising flues; the top of each of the plurality of straight rising flues is connected with the top of the turning smoke chamber; the side wall of the turning smoke chamber and the side wall of each of the plurality of straight rising flues are a membrane water cooling wall; an upper header is arranged at the top of the membrane water cooling wall; and a lower header is arranged at the bottom of the membrane water cooling wall; the upper header is connected with the collection header; the drum is connected with the top of the concentrated descending pipe; the bottom of the concentrated descending pipe is connected with the dispersion descending pipe; and the dispersion descending pipe is connected with the lower header.

[0007] The waste heat boiler of the present application can be connected with a plurality of side blowing furnaces simultaneously, and the smoke gas of the plurality of side blowing furnaces enters into the straight rising flues through the smoke gas inlets at the bottom of the straight rising flues and exchanges heat with the side wall of the straight rising flues. The smoke gas enters into the turning smoke chamber through the top of the straight rising flues, the smoke gas in the plurality of straight rising flues mixes and exchanges heat in the turning smoke chamber, the side wall of the turning smoke chamber exchanges heat with the smoke gas for the second time, and the heat-exchanged smoke gas is finally discharged through the smoke gas outlet. The steam and water generated by the water in the side wall of the turning smoke chamber and the side wall of the plurality of straight rising flues after exchanging heat with the smoke gas enters into the drum through the upper header and the collection header, the water in the drum enters into the lower header through the concentrated descending pipe and the dispersion descending pipe, and the steam and water in the lower header enters into the membrane water cooling wall of the turning smoke chamber and the plurality of straight rising flues to continue exchanging heat with the smoke gas, thereby realizing continuous circulation. The waste heat boiler of the present application can simultaneously exchange heat with a plurality of smoke gases and can exchange heat for multiple times, thereby greatly improving the heat exchange efficiency. The waste heat boiler of the present application adopts natural circulation for the circulating water required for heat exchange, thereby not needing to additionally install a circulating pump and saving construction cost. The waste heat boiler of the present application collects a plurality of smoke gases, thereby making the working condition of the smoke gas more stable and being beneficial to stable work of subsequent smoke gas treatment devices.

[0008] In order to improve the heat exchange efficiency, preferably, a plurality of partitions are arranged in the turning smoke chamber, the plurality of partitions separate the turning smoke chamber into a plurality of branch smoke chambers, and the plurality of branch smoke chambers are arranged along the height direction of the furnace body; a communication hole is arranged on the top or the bottom of each of the plurality of partitions, and the communication holes on adjacent partitions are arranged alternately. By arranging the plurality of partitions in the turning smoke chamber, the flow path of the smoke gas in the turning smoke chamber is prolonged, and the heat exchange efficiency of the smoke gas is further improved.

[0009] Preferably, the plurality of partitions are membrane water cooling walls, the top of each of the plurality of membrane water cooling walls is provided with the upper header, and the bottom of each of the plurality of membrane water cooling walls is provided with the lower header.

[0010] Preferably, the branch flue chamber is equipped with a gas-fired soot blower, which is located at the turning point of the flue gas flow within the branch flue chamber. Multiple gas-fired soot blowers installed at the flue gas turning point can periodically clean up the clogged soot, ensuring smooth flue gas flow and preventing positive pressure smoke from forming at the furnace opening.

[0011] Preferably, the centralized downcomer is provided in multiple sets, distributed in multiple direct-rise flues and / or multiple branch flue chambers. By placing the centralized downcomer in the direct-rise flues and branch flue chambers, the water within the centralized downcomer can exchange heat with the flue gas, improving the heat exchange efficiency between the boiler and the flue gas.

[0012] Preferably, the furnace body and the boiler drum are connected to the steel frame via a suspension device.

[0013] Preferably, a rain shelter is provided above the furnace body, and the rain shelter is connected to the steel frame.

[0014] Preferably, an ash discharge hopper is provided below the turning flue, and a scraper conveyor is provided below the ash discharge hopper. The scraper conveyor is connected to the ash discharge hopper via an expansion joint. A small amount of large dust particles in the flue gas in the vertical flue gradually descend and fall back into the side-blown furnace as the flue gas rises, while most of the dust in the flue gas follows the flue gas into the turning flue, where it settles and falls into the ash discharge hopper. The scraper conveyor below the ash discharge hopper operates continuously to discharge the dust from the ash discharge hopper.

[0015] Preferably, the side wall of the furnace body is provided with multiple maintenance manholes. The ash blockage inside the boiler can be observed through the maintenance manholes, and maintenance can be carried out inside the boiler through the maintenance manholes when the boiler is shut down.

[0016] Based on the same inventive concept, this application also provides a side-blown furnace waste heat recovery system, including two side-blown furnaces and a waste heat boiler as described above. The vertical flue is provided in two sections, and the flue gas outlets of the two side-blown furnaces are respectively connected to the flue gas inlets of the two vertical flue sections.

[0017] The side-blown furnace waste heat recovery system of this application allows two side-blown furnaces to share one boiler, which occupies a smaller area and has a shorter construction cost and construction period. Furthermore, the combined flue gas from the two side-blown furnaces can make the flue gas conditions more stable, which is conducive to the stable operation of subsequent flue gas treatment equipment.

[0018] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0019] 1. The waste heat boiler of this utility model can simultaneously exchange heat from multiple flue gas streams and perform multiple heat exchanges, which greatly improves the heat exchange efficiency.

[0020] 2. The waste heat boiler of this utility model uses natural circulation for the circulating water required for heat exchange, eliminating the need for an additional circulation pump and saving construction costs.

[0021] 3. The side-blown furnace waste heat recovery system of this application allows two side-blown furnaces to share one boiler, which occupies a smaller area and has a shorter construction cost and construction period.

[0022] 4. The side-blown furnace waste heat recovery system of this application combines the flue gas from two side-blown furnaces in the waste heat boiler, making the flue gas conditions more stable and conducive to the stable operation of subsequent flue gas treatment equipment. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the flue gas flow path of the waste heat boiler of this utility model;

[0024] Figure 2 This is a schematic diagram of the waste heat boiler structure of this utility model;

[0025] Figure 3 yes Figure 2 Schematic diagram of the horizontal cross-section structure in the middle of the furnace body.

[0026] In the figure

[0027] 1-Furnace body, 2-Bend smoke chamber, 201-Branch smoke chamber, 3-Vertical flue, 4-Combination header, 5-Boiler drum, 6-Flue gas outlet, 7-Flue gas inlet, 8-Lower header, 9-Distributed downcomer, 10-Centralized downcomer, 11-Suspension device, 12-Steel frame, 13-Partition, 14-Connecting hole, 15-Ash hopper, 16-Scraper conveyor, 17-Expansion joint, 18-Gas soot blower, 19-Maintenance manhole, 20-Rain shelter, 21-Upper header. Detailed Implementation

[0028] The present invention will be described in detail below with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in the embodiments of the present invention can be combined with each other. For ease of description, the terms "upper," "lower," "left," and "right" appearing below only indicate that they correspond to the upper, lower, left, and right directions in the accompanying drawings and do not limit the structure.

[0029] like Figure 2 As shown, a waste heat boiler in this embodiment includes a furnace body 1. Multiple maintenance manholes 19 are provided on the side walls of the furnace body 1. Inside the furnace body 1, a turning flue 2, two vertical flues 3, and multiple sets of centralized downcomers 10 are arranged side-by-side along the height direction. A collection box 4 and a boiler drum 5 connected to the collection box 4 are provided at the top of the furnace body 1. Distributed downcomers 9 are provided at the bottom of the furnace body 1. The furnace body 1 and the boiler drum 5 are mounted on a steel frame 12 via a suspension device 2. A rain shelter 20 is provided above the furnace body 1 and is connected to the steel frame 12. Each of the two vertical flues 3 has a flue gas inlet 7 at its bottom, and the tops of the two vertical flues 3 are connected, with the top of one of the vertical flues 3 connected to the top of the turning flue 2.Figure 3 As shown, the turning smoke chamber 2 is equipped with three partitions 13, which divide the turning smoke chamber 2 into four parallel branch smoke chambers 201. All four branch smoke chambers 201 are arranged along the height direction of the furnace body 1. Multiple sets of centralized downcomers 10 are distributed within the two vertical flues 3 and the four branch smoke chambers 201. Each of the three partitions 13 has a connecting hole 14 at its top or bottom. The connecting holes 14 on the branch smoke chambers 201 that connect to the vertical flues 3 are located at the bottom of the partition 13, and the connecting holes 14 on adjacent partitions 13 are staggered. Figure 1 As indicated by the arrows within the central turning smoke chamber 2, flue gas flows through four branch smoke chambers 201. Along the flue gas flow direction, the top of the branch smoke chamber 201 into which the flue gas finally flows is equipped with a flue gas outlet 6. Multiple gas-fired soot blowers 18 are installed within each branch smoke chamber 201, positioned at the turning points of the flue gas flow. The specifications of the gas-fired soot blowers 18 are HDZ-325 / 159-20 / 20-JZ. The side walls of the turning smoke chamber 2, the two vertical flue ducts 3, and the three partitions 13 are all membrane water-cooled walls. Each membrane water-cooled wall has an upper header 21 at its top and a lower header 8 at its bottom. The upper header 21 is connected to the central header 4. The boiler drum 5 is connected to the top of the centralized downcomer 10, and the bottom of the centralized downcomer 10 is connected to the decentralized downcomer 9. The decentralized downcomer 9 is connected to the lower header 8. Below the turning smoke chamber 2, there is an ash discharge hopper 15, and below the ash discharge hopper 15, there is a scraper conveyor 16. The scraper conveyor 16 is connected to the ash discharge hopper 15 through an expansion joint 17.

[0030] This embodiment also provides a side-blown furnace waste heat recovery system, including two side-blown furnaces and a waste heat boiler as described above. The flue gas outlets of the two side-blown furnaces are respectively connected to the flue gas inlets 7 of two vertical flue ducts 3.

[0031] When the side-blown furnace waste heat recovery system is running, such as Figure 1As shown, the smelting flue gas from the two side-blown furnaces enters the waste heat boiler through the flue gas inlet 7 and exchanges heat with the membrane water-cooled walls of the two vertical flue ducts 3. A small amount of large dust particles in the smelting flue gas gradually descends in the vertical flue duct 3 and falls back into the side-blown furnace, allowing the metal volatilized during smelting in the side-blown furnace to be fully oxidized and enter the dust. Most of the remaining dust in the smelting flue gas follows the flue gas into the subsequent turning chamber 2. In the turning chamber 2, the smelting flue gas converges and flows sequentially along the four branch chambers 201 for further heat exchange and cooling, and is finally discharged from the flue gas outlet 6. The dust in the smelting flue gas settles into the ash discharge hopper 15 in the turning chamber 2. The scraper conveyor 16 below the ash discharge hopper 15 operates continuously, discharging the ash from the ash discharge hopper 15. The steam-water mixture generated after heat exchange between the water in the side walls of the transition flue 2, the vertical flue 3, and the partition 13 and the flue gas enters the boiler drum 5 through the upper headers 21 and the central header 4. The water in the boiler drum 5 then enters the lower headers 8 through the central downcomer 10 and the decentralized downcomer 9. The steam-water mixture in the lower headers 8 enters the membrane water-cooled walls of the transition flue 2, the vertical flue 3, and the partition 13 to continue heat exchange with the flue gas, continuously circulating. In this embodiment, the waste heat boiler uses natural circulation, eliminating the need for an additional circulation pump. The circulation loops of each group of central downcomers 14 and decentralized downcomers 15 operate independently, ensuring long-term stable operation. The boiler's internal ash blockage can be observed through the maintenance manhole 19, and maintenance can be performed through the manhole 19 during shutdown. Multiple gas-fired soot blowers 18 installed at the flue gas transition points periodically clean the blocked soot, ensuring smooth flue gas flow and preventing positive pressure smoke from the furnace opening.

[0032] The above embodiments should be understood as being used only to illustrate the present invention more clearly, and not to limit the scope of the present invention. After reading the present invention, any modifications of the embodiments by those skilled in the art in various equivalent forms fall within the scope defined by the appended claims.

Claims

1. A waste heat boiler, comprising a boiler body (1), characterized in that: The furnace body (1) is provided with a turning smoke chamber (2), a centralized downcomer (10) and multiple vertical flues (3) arranged in parallel along the height direction. The top of the furnace body (1) is provided with a collection box (4) and a boiler drum (5) connected to the collection box (4). The bottom of the furnace body (1) is provided with a distributed downcomer (9). The side wall of the turning smoke chamber (2) is provided with a smoke outlet (6), and the bottom of the multiple vertical smoke ducts (3) is provided with a smoke inlet (7). The top of the multiple vertical smoke ducts (3) is connected to the top of the turning smoke chamber (2). The side walls of the turning smoke chamber (2) and the vertical flue (3) are both membrane water-cooled walls. The top of the membrane water-cooled wall is provided with an upper header (21), and the bottom of the membrane water-cooled wall is provided with a lower header (8). The upper header (21) is connected to the summarizing header (4), the boiler drum (5) is connected to the top of the centralized downcomer (10), the bottom of the centralized downcomer (10) is connected to the decentralized downcomer (9), and the decentralized downcomer (9) is connected to the lower header (8).

2. The waste heat boiler according to claim 1, characterized in that: The turning smoke chamber (2) is provided with multiple partitions (13), which divide the turning smoke chamber (2) into multiple branch smoke chambers (201). The multiple branch smoke chambers (201) are all arranged along the height direction of the furnace body (1). The top or bottom of the multiple partitions (13) are provided with connecting holes (14), and the connecting holes (14) on adjacent partitions (13) are staggered.

3. The waste heat boiler according to claim 2, characterized in that: The partitions (13) are all membrane water-cooled walls, with the upper manifold (21) at the top and the lower manifold (8) at the bottom.

4. The waste heat boiler according to claim 2, characterized in that: The branch smoke chamber (201) is equipped with a gas soot blower (18), which is located at the turning point of the flue gas flow in the branch smoke chamber (201).

5. The waste heat boiler according to claim 2, characterized in that: The centralized downcomer (10) is provided in multiple sets, and the multiple sets of centralized downcomers (10) are distributed in multiple vertical flues (3) and / or multiple branch smoke chambers (201).

6. The waste heat boiler according to claim 1, characterized in that: The furnace body (1) and the boiler drum (5) are connected to the steel frame (12) by a suspension device (11).

7. The waste heat boiler according to claim 6, characterized in that: The furnace body (1) is provided with a rain shelter (20) above it, which is connected to the steel frame (12).

8. The waste heat boiler according to any one of claims 1 to 7, characterized in that: Below the turning smoke chamber (2) is a ash discharge hopper (15), and below the ash discharge hopper (15) is a scraper conveyor (16), which is connected to the ash discharge hopper (15) through an expansion joint (17).

9. The waste heat boiler according to any one of claims 1 to 7, characterized in that: The furnace body (1) has multiple maintenance manholes (19) on its side wall.

10. A side-blown furnace waste heat recovery system, comprising two side-blown furnaces, characterized in that: It also includes a waste heat boiler as described in any one of claims 1 to 9, wherein there are two vertical flue ducts (3), and the flue gas outlets of the two side-blown furnaces are respectively connected to the flue gas inlets (7) of the two vertical flue ducts (3).

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