A continuous pipe casting production line with multiple waste heat conversion and reuse systems

Abstract

This utility model relates to the field of cast iron pipe production technology, and provides a multi-functional waste heat conversion and reuse system for a continuous cast iron pipe production line, including: an annealing furnace waste heat conversion system, a preheating furnace heating system, a drying furnace heating system, and a curing pit gas supply system; the annealing furnace waste heat conversion system includes: an annealing furnace cooling circulation system, an annealing furnace hot flue gas emission system, a heat exchange system, and a steam conversion system; the annealing furnace cooling circulation system is connected to the steam conversion system; the annealing furnace hot flue gas emission system is connected to the furnace chamber of the annealing furnace, and a heat exchange system is installed on the annealing furnace hot flue gas emission system; the heat exchange system is connected to the preheating furnace heating system and the drying furnace heating system through hot air conveying pipelines; the steam conversion system is connected to the curing pit gas supply system through steam conveying pipelines. This utility model enables the heat energy discharged from the annealing furnace to be fully converted and reused, achieving energy saving, emission reduction, and cost savings.

Description

Technical Field

[0001] This utility model relates to the field of cast iron pipe production technology, and in particular to a multi-waste heat conversion and reuse system for a continuous cast iron pipe production line. Background Technology

[0002] The production line for ductile iron pipes includes processes such as molten iron preparation, sand core preparation, centrifugal casting, annealing, zinc spraying, hydrostatic testing, cement lining, asphalt spraying, and packaging.

[0003] The continuous annealing furnace is used to anneal the cast iron pipe by heating, holding, rapid cooling and slow cooling, which eliminates cementite and pearlite generated during the casting process and transforms the matrix into ferrite.

[0004] After the cement lining of the cast iron pipe is applied, a curing process is required through a curing pit. By using high-temperature, humid steam, the cement lining of the cast iron pipe is cured in a closed curing tank, which accelerates the hydration reaction of the cement layer and allows it to reach the required compressive strength as quickly as possible in a short period of time.

[0005] Before asphalt spraying, a preheating process is required in a preheating furnace. High-temperature treatment ensures that the asphalt reaches the ideal viscosity and fluidity during the spraying process, thereby better adhering to the surface of the cast pipe and forming a uniform and dense protective layer.

[0006] After asphalt spraying, a drying process is required in a drying oven to ensure that the asphalt paint is sprayed evenly and dried thoroughly, thereby improving the quality and durability of the cast pipe.

[0007] Currently, the hot flue gas generated by the annealing furnace is directly discharged outside the factory through the chimney, causing huge energy waste and environmental pollution. The heat of the preheating furnace is provided by a hot air generator with burners, the heat of the drying furnace is provided by a hot air generator with burners, and the steam of the curing pit is provided by a steam boiler. The heat energy discharged from the annealing furnace is not converted and reused, resulting in a large amount of energy waste. Utility Model Content

[0008] This invention primarily addresses the technical problem that the heat energy discharged from existing annealing furnaces is not converted and reused, leading to significant energy waste. It proposes a multi-waste heat conversion and reuse system for a continuous pipe casting production line, which converts excess hot flue gas in the rapid cooling and slow cooling sections into hot air and steam. This enables the heat energy discharged from the annealing furnace to be fully converted and reused, achieving energy conservation, emission reduction, and cost savings.

[0009] This utility model provides a multi-waste heat conversion and reuse system for a continuous pipe casting production line, including: an annealing furnace waste heat conversion system, a preheating furnace heating system, a drying furnace heating system, and a curing pit gas supply system.

[0010] The annealing furnace waste heat conversion system includes: an annealing furnace cooling circulation system, an annealing furnace hot flue gas emission system, a heat exchange system, and a steam conversion system;

[0011] The annealing furnace cooling circulation system is connected to the steam reforming system; the annealing furnace hot flue gas emission system is connected to the furnace chamber of the annealing furnace, and a heat exchange system is installed on the annealing furnace hot flue gas emission system;

[0012] The heat exchange system is connected to the preheating furnace heating system and the drying furnace heating system via hot air delivery pipelines.

[0013] The steam conversion system is connected to the gas supply system of the curing pit via a steam transmission pipeline.

[0014] Preferably, the preheating furnace heating system includes: a preheating furnace high-temperature air pipe, a preheating furnace hot flue gas pipe, a heating device, a preheating furnace induced draft fan, a mixing box, a preheating furnace heating main pipe, and a preheating furnace heating branch pipe.

[0015] The inlet end of the high-temperature air pipe of the preheating furnace is connected to the hot air delivery pipeline;

[0016] The preheating furnace has two hot flue gas pipes, and the inlet ends of the two preheating furnace hot flue gas pipes are respectively connected to the preheating furnace exhaust port.

[0017] The output ends of the high-temperature air pipe of the preheating furnace and the output ends of the two hot flue gas pipes of the preheating furnace are connected to the induced draft fan of the preheating furnace through the air mixing zone of the preheating furnace.

[0018] The output end of the preheating furnace induced draft fan is connected to the mixing box; the mixing box is connected to the preheating furnace heating main pipe, and multiple preheating furnace heating branch pipes are installed on the preheating furnace heating main pipe; the multiple preheating furnace heating branch pipes extend into the furnace chamber of the preheating furnace.

[0019] Preferably, an electric regulating valve for the preheating furnace is installed on the high-temperature air pipe of the preheating furnace;

[0020] An explosion-proof device is installed on the main heating pipe of the preheating furnace.

[0021] Preferably, the preheating furnace heating system further includes: a preheating furnace air curtain;

[0022] The air curtain of the preheating furnace is set at the furnace opening at the front end of the preheating furnace.

[0023] Preferably, the drying oven heating system includes: a low-temperature hot air duct for the drying oven, a high-temperature air duct for the drying oven, a hot flue gas duct for the drying oven, an induced draft fan for the drying oven, a main heating pipe for the drying oven, and branch heating pipes for the drying oven.

[0024] The inlet of the low-temperature hot air pipe of the drying oven is connected to the main heating pipe of the preheating oven heating system.

[0025] The input end of the high-temperature air pipe of the drying oven is connected to the hot air delivery pipeline;

[0026] The drying oven has two hot flue gas pipes, and the input ends of the two hot flue gas pipes are respectively connected to the exhaust port of the drying oven.

[0027] The output ends of the low-temperature hot air pipe, the high-temperature air pipe, and the two hot flue gas pipes of the drying furnace are connected to the induced draft fan of the drying furnace through the air mixing zone of the drying furnace.

[0028] The output end of the induced draft fan of the drying oven is connected to the main heating pipe of the drying oven; multiple heating branch pipes of the drying oven are installed on the main heating pipe of the drying oven; multiple heating branch pipes of the drying oven extend into the drying oven.

[0029] Preferably, a first electric regulating valve for the drying oven is installed on the low-temperature hot air duct of the drying oven;

[0030] A second electric regulating valve for the drying oven is installed on the high-temperature air pipe of the drying oven.

[0031] Preferably, the drying oven heating system further includes: a drying oven air curtain;

[0032] The air curtain of the drying oven is located at the oven opening at the rear end of the drying oven.

[0033] Preferably, the gas supply system for the health preservation pit includes: a main steam pipe for the health preservation pit and multiple branch steam pipes for the health preservation pit;

[0034] The steam main pipe of the curing pit is connected to the steam transmission pipeline; multiple U-shaped anti-expansion pipes are installed on the steam main pipe of the curing pit;

[0035] The steam branch pipe of the curing pit is connected to the main steam pipe of the curing pit;

[0036] The steam branch pipe of the health preservation pit enters the bottom of the health preservation pool and penetrates the bottom of the pool. Multiple steam nozzles of the health preservation pit are opened on the steam branch pipe.

[0037] This invention provides a multi-waste heat conversion and reuse system for a continuous pipe casting production line. It converts excess hot flue gas from the rapid cooling and slow cooling sections of the annealing furnace into hot air and steam. These two forms of heat energy are supplied to three types of furnaces on the production line: the preheating furnace, the drying furnace, and the curing pit. The annealing furnace is a high-temperature furnace, while the drying and preheating furnaces are low-temperature furnaces. This invention not only meets the rapid cooling requirements of the rapid cooling and slow cooling sections of the annealing furnace but also simultaneously converts excess hot flue gas from these sections into hot air and steam. This ensures the full conversion and reuse of the heat energy discharged from the annealing furnace, achieving energy conservation, emission reduction, cost savings, and green production. This invention solves the cooling process problem of the annealing furnace and rationally utilizes its waste heat, successfully converting it into hot air and steam. This solves the steam problem for the curing pit and the heating problem for the drying and preheating furnaces, while also effectively addressing VOC waste treatment. It significantly saves resources, reduces costs, and improves the quality of the production environment. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the structure of the multiple waste heat conversion and reuse system of the continuous casting pipe production line provided by this utility model;

[0039] Figure 2 This is a schematic diagram of the preheating furnace heating system provided by this utility model;

[0040] Figure 3 This is a schematic diagram of the heating system for the drying oven provided by this utility model;

[0041] Figure 4 This is a schematic diagram of the structure of the health-preserving pit air supply system provided by this utility model;

[0042] Figure 5 This is a schematic diagram of the structure of the annealing furnace waste heat conversion system provided by this utility model;

[0043] Figure 6 This is a schematic diagram of the cooling circulation system of the annealing furnace provided by this utility model;

[0044] Figure 7 This is a top view schematic diagram of the annealing furnace hot flue gas emission system provided by this utility model;

[0045] Figure 8 This is a side view schematic diagram of the annealing furnace hot flue gas emission system provided by this utility model;

[0046] Figure 9 This is a schematic diagram of the heat exchange system provided by this utility model;

[0047] Figure 10 This is a schematic diagram of the steam reforming system provided by this utility model.

[0048] Attached reference numerals: 1. Annealing furnace waste heat conversion system; 2. Preheating furnace heating system; 3. Drying furnace heating system; 4. Curing pit air supply system; 5. VOC exhaust gas pipeline; 6. Hot air conveying pipeline; 7. Steam conveying pipeline; 8. Spray booth; 9. VOC exhaust gas pipeline induced draft fan;

[0049] 101. Annealing furnace cooling circulation system; 102. Annealing furnace hot flue gas exhaust system; 103. Heat exchange system; 104. Steam reforming system; 105. Annealing furnace quenching section; 106. Annealing furnace slow cooling section; 107. Annealing furnace heating section;

[0050] 201. High-temperature air duct of preheating furnace; 202. Electric regulating valve of preheating furnace; 203. Hot flue gas duct of preheating furnace; 204. Heating device; 205. Exhaust fan of preheating furnace; 206. Mixing box; 207. Explosion-proof device; 208. Main heating pipe of preheating furnace; 209. Branch heating pipe of preheating furnace; 210. Flue gas outlet of preheating furnace; 211. Mixing zone of preheating furnace; 212. Air curtain of preheating furnace;

[0051] 301. Low-temperature hot air duct of the drying oven; 302. Electric regulating valve of the first drying oven; 303. High-temperature air duct of the drying oven; 304. Electric regulating valve of the second drying oven; 305. Hot flue gas duct of the drying oven; 306. Exhaust fan of the drying oven; 307. Main heating pipe of the drying oven; 308. Branch heating pipe of the drying oven; 309. Flue gas outlet of the drying oven; 310. Mixing air zone of the drying oven; 311. Air curtain of the drying oven;

[0052] 401. Steam main pipe of the curing pit; 402. Manual shut-off valve of the first curing pit; 403. Manual shut-off valve of the second curing pit; 404. Electric regulating valve of the curing pit; 405. U-shaped anti-expansion pipe; 406. Steam branch pipe of the curing pit; 407. Steam nozzle of the curing pit;

[0053] 10101. Rapid cooling section air intake unit; 10102. Slow cooling section air intake unit; 10103. Furnace top standby cooling device; 10104. First regulating valve; 10105. Second regulating valve; 10106. Circulation device; 10107. Main cold air pipeline; 10108. Branch cold air pipeline;

[0054] 10201, First smoke exhaust outlet; 10202, Second smoke exhaust outlet; 10203, Thermal insulation cotton; 10204, Main smoke exhaust pipe; 10205, First flue gate valve; 10206, Second flue gate valve;

[0055] 10303, Cold air inlet pipe; 10304, Hot air outlet pipe; 10305, Exhaust fan of heat exchange system; 10306, Heat exchanger;

[0056] 10401 Steam boiler; 10402 Economizer; 10403 Condenser; 10404 Softened water tank; 10405 Feed water pump; 10406 ​​Circulating water pump; 10407 Gas distribution cylinder; 10408 Economizer inlet pipe; 10409 Economizer outlet pipe; 10410 Economizer intermediate pipeline; 10411 Sewage discharge equipment. Detailed Implementation

[0057] To make the technical problems solved by this utility model, the technical solutions adopted, and the technical effects achieved clearer, this utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely for explaining this utility model and not for limiting it. Furthermore, it should be noted that, for ease of description, only the parts related to this utility model are shown in the accompanying drawings, not all of them.

[0058] like Figure 1 As shown in the figure, the present invention provides a continuous casting pipe production line with multiple waste heat conversion and reuse systems, including: annealing furnace waste heat conversion system 1, preheating furnace heating system 2, drying furnace heating system 3, and curing pit gas supply system 4.

[0059] The annealing furnace waste heat conversion system 1 includes: an annealing furnace cooling circulation system 101, an annealing furnace hot flue gas emission system 102, a heat exchange system 103, and a steam conversion system 104. The annealing furnace cooling circulation system 101 is connected to the steam conversion system 104; the annealing furnace hot flue gas emission system 102 is connected to the furnace chamber of the annealing furnace, and the heat exchange system 103 is installed on the annealing furnace hot flue gas emission system 102; the heat exchange system 103 is connected to the preheating furnace heating system 2 and the drying furnace heating system 3 through a hot air conveying pipeline 6; and the steam conversion system 104 is connected to the curing pit gas supply system 4 through a steam conveying pipeline 7.

[0060] like Figure 2 As shown, the preheating furnace heating system 2 includes: a preheating furnace high-temperature air pipe 201, a preheating furnace hot flue gas pipe 203, a heating device 204, a preheating furnace induced draft fan 205, a mixing box 206, a preheating furnace heating main pipe 208, and a preheating furnace heating branch pipe 209.

[0061] The input end of the preheating furnace high-temperature air pipe 201 is connected to the hot air conveying pipeline 6; there are two preheating furnace hot flue gas pipes 203, and the input ends of the two preheating furnace hot flue gas pipes 203 are respectively connected to the preheating furnace exhaust port 210; the output ends of the preheating furnace high-temperature air pipe 201 and the output ends of the two preheating furnace hot flue gas pipes 203 are connected to the preheating furnace induced draft fan 205 through the preheating furnace mixing zone 211; the output end of the preheating furnace induced draft fan 205 is connected to the mixing box 206; the mixing box 206 is connected to the preheating furnace heating main pipe 208, and multiple preheating furnace heating branch pipes 209 are installed on the preheating furnace heating main pipe 208; the multiple preheating furnace heating branch pipes 209 extend into the furnace chamber of the preheating furnace. A preheating furnace electric regulating valve 202 is installed on the preheating furnace high-temperature air pipe 201; an explosion-proof device 207 is installed on the preheating furnace heating main pipe 208.

[0062] The preheating furnace heating system 2 further includes a preheating furnace air curtain 212; the preheating furnace air curtain 212 is installed at the furnace opening at the front end of the preheating furnace. The preheating furnace induced draft fan 205 blows air into the furnace chamber, and the air is blown out from the top of the furnace through an upward-opening oblique opening above the furnace top, forming an air curtain.

[0063] like Figure 3 As shown, the drying oven heating system 3 includes: a low-temperature hot air pipe 301, a high-temperature air pipe 303, a hot flue gas pipe 305, an induced draft fan 306, a main heating pipe 307, and a branch heating pipe 308.

[0064] The input end of the low-temperature hot air pipe 301 of the drying oven is connected to the preheating furnace heating main pipe 208 of the preheating furnace heating system 2; the input end of the high-temperature air pipe 303 of the drying oven is connected to the hot air conveying pipeline 6; there are two hot flue gas pipes 305 of the drying oven, and the input ends of the two hot flue gas pipes 305 are respectively connected to the exhaust port 309 of the drying oven; the output ends of the low-temperature hot air pipe 301, the high-temperature air pipe 303, and the two hot flue gas pipes 305 are connected to the induced draft fan 306 of the drying oven through the air mixing zone 310 of the drying oven.

[0065] The output end of the induced draft fan 306 of the drying oven is connected to the main heating pipe 307 of the drying oven; multiple heating branch pipes 308 of the drying oven are provided on the main heating pipe 307 of the drying oven; the multiple heating branch pipes 308 of the drying oven extend into the drying oven.

[0066] A first electric regulating valve 302 is installed on the low-temperature hot air pipe 301 of the drying oven; a second electric regulating valve 304 is installed on the high-temperature air pipe 303 of the drying oven.

[0067] The drying oven heating system 3 further includes: a drying oven air curtain 311; the drying oven air curtain 311 is installed at the oven opening at the rear end of the drying oven. The drying oven induced draft fan 306 blows air into the furnace chamber, and the air is blown out from the top of the oven through the upward-opening oblique opening above the top of the oven, forming an air curtain.

[0068] The rear end of the preheating furnace and the front end of the drying furnace are connected to the spray booth 8, thus forming a relatively isolated space between the drying furnace, preheating furnace, and spray booth 8 and the outside world. This successfully prevents the escape of hot gas from the furnace. At the same time, the VOC waste gas generated in this space is connected to the heating section 107 of the annealing furnace through the VOC waste gas pipeline 5. A VOC waste gas pipeline exhaust fan 9 is installed in the middle, which can draw the VOC waste gas from the furnace side of the preheating furnace and send it into the annealing furnace for combustion, decomposing the harmful gases into carbon dioxide and water, effectively protecting the environment.

[0069] like Figure 4 As shown, the steam supply system 4 for the conditioning pit includes: a main steam pipe 401 and multiple branch steam pipes 406. The main steam pipe 401 is connected to the steam delivery pipeline 7; multiple U-shaped anti-expansion pipes 405 are installed on the main steam pipe 401; the branch steam pipes 406 are connected to the main steam pipe 401; the branch steam pipes 406 enter the bottom of the conditioning pool and penetrate the bottom of the pool, and multiple steam nozzles 407 are opened on the branch steam pipes 406.

[0070] The working principle of this utility model is as follows: The waste heat conversion system 1 of the annealing furnace converts the high-temperature flue gas from the rapid cooling section 105 and the slow cooling section 106 of the annealing furnace into high-temperature hot air through the heat exchange system 103 (heat exchanger 10306), and then into steam through the steam conversion system 104 (steam boiler 10401). The high-temperature hot air is delivered to the high-temperature air pipe 201 of the preheating furnace and the low-temperature hot air pipe 301 of the drying furnace through the hot air delivery pipeline 6. Both the high-temperature air pipe 201 of the preheating furnace and the low-temperature hot air pipe 301 of the drying furnace are equipped with electric regulating valves. The valve opening is controlled according to the furnace temperature to control the amount of high-temperature air delivered to the drying furnace and the preheating furnace, respectively.

[0071] When the preheating furnace is working, high-temperature air enters the preheating furnace mixing zone 211 through the preheating furnace electric regulating valve 202 and the preheating furnace high-temperature air pipe 201. At the same time, the hot flue gas in the preheating furnace also enters the preheating furnace mixing zone 211 through the preheating furnace exhaust port 210. After the two hot gases are mixed, the high-temperature air is sent to the mixing box 206 by the preheating furnace induced draft fan 205, and then sent to the preheating furnace heating branch pipe 209 through the preheating furnace heating main pipe 208 to preheat the furnace chamber for casting pipe preheating; the other path is sent to the drying furnace low-temperature hot air pipe 301 for use by the drying furnace.

[0072] When the drying furnace is working, the high-temperature hot air from the annealing furnace waste heat conversion system 1, the flue gas discharged from the drying furnace exhaust port 306, and part of the low-temperature flue gas from the preheating furnace heating main pipe 208 are mixed in the drying furnace mixing zone 310. The mixed air is then sent into the furnace chamber of the drying furnace through the drying furnace heating main pipe 307 and the drying furnace heating branch pipe 308 by the drying furnace induced draft fan 306 to dry the cast pipe.

[0073] When the high-temperature air volume in the annealing furnace is insufficient to meet the needs of the preheating furnace and drying furnace, the heating device 204 on the preheating furnace is activated. When the heating device 204 is activated, the heat generated by the combustion of natural gas burners enters the mixing box 206 and mixes with the air mixed in the preheating furnace. Through the preheating furnace heating main pipe 208, one path is sent to the preheating furnace heating branch pipe 207, which is then fed into the furnace chamber of the preheating furnace to preheat the cast pipes. The other path is sent to the low-temperature hot air pipe 301 of the drying furnace for use in the drying furnace.

[0074] When the curing tank is in operation, steam is transported from the steam conversion system 104 of the annealing furnace waste heat conversion system 1 to the main steam pipe 401 of the curing pit in front of the curing tank via steam transmission pipeline 7. There are generally several to a dozen or even dozens of curing tanks. At regular intervals along the direction of the main steam pipe 401 of the curing pit, a U-shaped anti-expansion pipe 405 is installed to prevent the main steam pipe 401 of the curing pit from expanding due to thermal stress. The steam branch pipe 406 in front of each curing tank is divided into two paths. One path is equipped with a curing pit electric regulating valve 404, and a first curing pit manual shut-off valve 402 is installed before and after the curing pit electric regulating valve 404, which can effectively regulate the steam consumption and also meet the needs of each curing pit to be shut down for maintenance independently. The other path is a backup pipeline, equipped with a second curing pit manual shut-off valve 403. When the first valve is damaged or under maintenance, the backup pipeline can be temporarily activated without affecting production. After the two pipelines merge, the steam branch pipe 406 of the health-preserving pit enters the bottom of the health-preserving pool from the hole on the side of the pool, and splits into two lines that run through the bottom of the pool. On the upper side of the two bottom pipelines, multiple steam nozzles 407 of the health-preserving pit are opened to release steam.

[0075] To ensure the clarity and completeness of the present invention, the waste heat conversion system 1 of the annealing furnace is described. However, those skilled in the art will understand that the waste heat conversion system 1 of the annealing furnace can take many forms and is not limited to this. This embodiment provides a detailed description:

[0076] like Figure 5 As shown, the annealing furnace waste heat conversion system 1 includes: an annealing furnace cooling circulation system 101, a hot flue gas emission system 102, a heat exchange system 103, and a steam conversion system 104.

[0077] like Figure 6As shown, the annealing furnace cooling circulation system 101 includes: a circulation device 10106, a rapid cooling section air inlet unit 10101, and a slow cooling section air inlet unit 10102; the input end of the circulation device 10106 is connected to the steam reforming system 104, and the output end of the circulation device 10106 is connected to the pipelines of the rapid cooling section air inlet unit 10101 and the slow cooling section air inlet unit 10102 respectively; the circulation device 10106 includes a circulating induced draft fan, a connection port, and corresponding connection pipelines; the connection port of the circulation device 10106 is connected to the condenser 10403 of the steam reforming system 104.

[0078] The rapid cooling section air inlet unit 10101 and the slow cooling section air inlet unit 10102 extend into the furnace chamber of the annealing furnace. The rapid cooling section air inlet unit 10101 and the slow cooling section air inlet unit 10102 each include a main cold air pipeline 10107 and multiple cold air branch pipelines 10108 connected to the main cold air pipeline 10107. The cold air branch pipelines 10108 enter the furnace chamber through the top of the annealing furnace.

[0079] A first regulating valve 10104 is provided on the connecting pipe between the output end of the circulation device 10106 and the rapid cooling section air inlet unit 10101. The first regulating valve 10104 is specifically provided on the cold air main pipe 10107 of the rapid cooling section air inlet unit 10101. A second regulating valve 10105 is provided on the connecting pipe between the output end of the circulation device 10106 and the slow cooling section air inlet unit 10102. The second regulating valve 10105 is specifically provided on the cold air main pipe 10107 of the slow cooling section air inlet unit 10102.

[0080] The rapid cooling section air inlet unit 10101 and the slow cooling section air inlet unit 10102 are also connected to the furnace top backup cooling device 10103 via pipelines; the furnace top backup cooling device 10103 is installed on the furnace top of the annealing furnace. The furnace top backup cooling device 10103 mainly consists of a backup induced draft fan, a regulating valve, and pipelines, which are connected to the main cold air pipeline 10107 of the rapid cooling section 105 and the slow cooling section 106 of the annealing furnace.

[0081] The annealing furnace hot flue gas exhaust system 102 is connected to the furnace chamber of the annealing furnace. For example... Figure 7-8 As shown, the annealing furnace hot flue gas emission system 102 includes: a first flue gas outlet 10201, a second flue gas outlet 10202, and a main flue gas pipeline 10204.

[0082] The first exhaust port 10201 is located at the bottom of the annealing furnace quench section 105, and the second exhaust port 10202 is located at the bottom of the annealing furnace slow cooling section 106; the first exhaust port 10201 and the second exhaust port 10202 are connected to the main exhaust pipe 10204; the main exhaust pipe 10204 is connected to the flue gas inlet of the steam reforming system 104.

[0083] A first flue gate valve 10205 is installed on the connecting pipe between the first smoke exhaust outlet 10201 and the main smoke exhaust pipe 10204; a second flue gate valve 10206 is installed on the connecting pipe between the second smoke exhaust outlet 10202 and the main smoke exhaust pipe 10204.

[0084] Insulation cotton 10203 is installed inside the first smoke exhaust outlet 10201, the second smoke exhaust outlet 10202, the main smoke exhaust pipe 10204, the connecting pipe between the first smoke exhaust outlet 10201 and the main smoke exhaust pipe 10204, and the connecting pipe between the second smoke exhaust outlet 10202 and the main smoke exhaust pipe 10204.

[0085] A heat exchange system 103 is installed on the annealing furnace hot flue gas exhaust system 102. For example... Figure 9 As shown, the heat exchange system 103 includes: a heat exchanger 10306, a cold air inlet pipe 10303, a hot air outlet pipe 10304, and a heat exchange system induced draft fan 10305.

[0086] The heat exchanger 10306 is installed on the main exhaust pipe 10204; a cold air inlet pipe 10303 and a hot air outlet pipe 10304 are connected to the heat exchanger 10306; the other end of the cold air inlet pipe 10303 is connected to the induced draft fan 10305 of the heat exchange system. The hot air outlet pipe 10304 is connected to the hot air delivery pipeline 6, and through the hot air delivery pipeline 6, it provides high-temperature air to the preheating furnace heating system 2 and the drying furnace heating system 3.

[0087] like Figure 10 As shown, the steam conversion system 104 includes: a steam boiler 10401, an economizer 10402, a condenser 10403, a softened water tank 10404, a feed water pump 10405, a circulating water pump 10406, and a steam distribution cylinder 10407.

[0088] The steam boiler 10401 has a flue gas inlet, a flue gas outlet, a steam outlet, and a water inlet. The flue gas inlet of the steam boiler 10401 is connected to the annealing furnace hot flue gas emission system 102, specifically to the main flue gas exhaust pipe 10204 of the annealing furnace hot flue gas emission system 102. The flue gas outlet of the steam boiler 10401 is connected to the circulation device 10106 of the annealing furnace cooling circulation system 101. The steam outlet of the steam boiler 10401 is connected to the gas distribution cylinder 10407, which is connected to the steam transmission pipeline 7, through which steam is supplied to the curing pit gas supply system 4. The water inlet of the steam boiler 10401 is connected to the economizer 10402 through the economizer outlet pipe 10409.

[0089] The steam boiler 10401 also has a vent and a drain outlet; the vent of the steam boiler 10401 is connected to the atmosphere through a pipeline and is equipped with a safety vent valve; the drain outlet of the steam boiler 10401 is connected to the drain equipment 10411 through a pipeline, and a ball valve and a steam trap are installed on the connecting pipeline, and the drain outlet is equipped with a drain valve.

[0090] The economizer 10402 is connected to the feedwater pump 10405 via the economizer inlet pipe 10408; the feedwater pump 10405 is connected to the softened water tank 10404; the economizer 10402 is connected to the inlet of the steam boiler 10401 via the economizer outlet pipe 10409; an intermediate economizer pipe 10410 connects the economizer inlet pipe 10408 and the economizer outlet pipe 10409, and a shut-off valve is installed on the intermediate economizer pipe 10410, allowing feedwater to directly enter the steam boiler 10401 when the economizer 10402 is not operating. The economizer outlet pipe 10409 is equipped with a shut-off valve, a check valve, a remote temperature thermocouple, and a remote pressure sensor. The economizer inlet pipe 10408 is equipped with a safety valve and a shut-off valve.

[0091] The inlet of the condenser 10403 is connected to the circulating water pump 10406, and a gate valve and a remote temperature thermocouple are installed on the connecting pipeline. The circulating water pump 10406 ​​is connected to the outlet of the softened water tank 10404; the outlet of the circulating water pump 10406 ​​is connected to the return outlet of the softened water tank 10404, and a gate valve and a remote temperature thermocouple are installed on the connecting pipeline. The inlet of the softened water tank 10404 is connected to tap water, and the softened water tank 10404 has its own softening treatment device.

[0092] The annealing furnace waste heat conversion system 1 provided by this utility model undergoes three heat exchange processes and two cooling processes, making full use of energy exchange to achieve maximum energy saving and consumption reduction. Working principle:

[0093] First heat exchange: High-temperature flue gas from the annealing furnace enters the steam boiler 10401 of the steam reforming system 104 via the first exhaust port 10201 at the bottom of the annealing furnace's rapid cooling section 105, through the main exhaust pipe 10204. Another source of high-temperature flue gas enters the heat exchanger 10306 via the second exhaust port 10202 at the bottom of the annealing furnace's slow cooling section 106, through the main exhaust pipe 10204, and exits from the furnace. The induced draft fan 10305 of the heat exchange system draws cold air into the heat exchanger 10306. After heat exchange, the high-temperature flue gas becomes medium-low temperature flue gas, which then flows to the steam boiler 10401 of the steam reforming system 104. The cold air becomes hot air and exits from the hot air outlet pipe 10304 of the heat exchanger 10306, then is supplied to the preheating furnace heating system 2 and the drying furnace heating system 3 via the hot air delivery pipeline 6.

[0094] Second heat exchange: The medium- and low-temperature flue gas discharged after the first heat exchange enters the steam boiler 10401 of the steam reforming system 104 for heat exchange with the softened water that enters the steam boiler 10401 after passing through the economizer 10402. After heat exchange, the softened water becomes steam, which is discharged from the steam outlet of the steam boiler 10401 and supplied to the curing pit gas supply system 4 through the steam transmission pipeline 7. The medium- and low-temperature flue gas becomes low-temperature flue gas and enters the economizer 10402.

[0095] The third heat exchange: The low-temperature flue gas entering the economizer 10402 and the softened water in the outer coil of the economizer 10402 undergo a third heat exchange. The low-temperature flue gas is further cooled down, and the softened water temperature increases before entering the steam boiler 10401 to become steam, which saves more external heat.

[0096] First cooling: The low-temperature flue gas discharged from the economizer 10402 enters the condenser 10403, and the water from the softened water tank 10404 enters the condenser 10403 via the circulating water pump 10406. This further cools the low-temperature flue gas from the economizer 10402, turning it into cooling air. The circulating water returns to the softened water tank 10404 after passing through the condenser 10403, which is equivalent to a small-scale heat exchange.

[0097] Secondary cooling: The cooling air discharged from the condenser 10403 is drawn through the circulation device 10106 to the rapid cooling section air inlet unit 10101 and the slow cooling section air inlet unit 10102, and then sent into the furnace to cool the furnace.

[0098] The above-mentioned quenching section 105 and slow cooling section 106 of the annealing furnace undergo a heat exchange process, which not only cools the area but also converts the excess heat of the flue gas in the furnace into high-temperature air and steam, so that the heat is fully utilized.

[0099] In addition, when the steam boiler 10401 is under maintenance or cannot operate for other reasons, the first flue gate valve 10205 and the second flue gate valve 10206 of the annealing furnace hot flue gas emission system 102 are closed; the furnace top standby cooling device 10103 is opened, and the annealing furnace can operate normally. Similarly, when the steam conversion system 104 is operating normally, the furnace top standby cooling device 10103 is closed.

[0100] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it; although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications to the technical solutions described in the foregoing embodiments, or equivalent substitutions for some or all of the technical features, do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A continuous pipe production line multi-excess heat conversion and recycling system, characterized in that, include: Annealing furnace waste heat conversion system (1), preheating furnace heating system (2), drying furnace heating system (3), curing pit gas supply system (4); The annealing furnace waste heat conversion system (1) includes: an annealing furnace cooling circulation system (101), an annealing furnace hot flue gas emission system (102), a heat exchange system (103), and a steam conversion system (104); The annealing furnace cooling circulation system (101) is connected to the steam reforming system (104); the annealing furnace hot flue gas emission system (102) is connected to the furnace chamber of the annealing furnace, and a heat exchange system (103) is provided on the annealing furnace hot flue gas emission system (102); The heat exchange system (103) is connected to the preheating furnace heating system (2) and the drying furnace heating system (3) through the hot air delivery pipeline (6); The steam conversion system (104) is connected to the gas supply system (4) of the health pit via a steam transmission pipeline (7).

2. The continuous pipe production line multi-excess heat conversion and recycling system according to claim 1, characterized in that, The preheating furnace heating system (2) includes: a preheating furnace high-temperature air pipe (201), a preheating furnace hot flue gas pipe (203), a heating device (204), a preheating furnace induced draft fan (205), a mixing box (206), a preheating furnace heating main pipe (208), and a preheating furnace heating branch pipe (209). The input end of the high-temperature air pipe (201) of the preheating furnace is connected to the hot air delivery pipeline (6); There are two preheating furnace hot flue gas pipes (203), and the input ends of the two preheating furnace hot flue gas pipes (203) are respectively connected to the preheating furnace exhaust port (210); The output end of the high-temperature air pipe (201) of the preheating furnace and the output ends of the two hot flue gas pipes (203) of the preheating furnace are connected to the induced draft fan (205) of the preheating furnace through the air mixing zone (211); The output end of the preheating furnace induced draft fan (205) is connected to the mixing box (206); the mixing box (206) is connected to the preheating furnace heating main pipe (208), and multiple preheating furnace heating branch pipes (209) are provided on the preheating furnace heating main pipe (208); the multiple preheating furnace heating branch pipes (209) extend into the furnace chamber of the preheating furnace.

3. The multi-exhaust heat conversion and reuse system of the continuous pipe production line according to claim 2, characterized in that, An electric regulating valve (202) for the preheating furnace is installed on the high-temperature air pipe (201) of the preheating furnace; An explosion-proof device (207) is installed on the preheating furnace heating main pipe (208).

4. The multi-exhaust heat conversion and reuse system of a continuous pipe production line according to claim 1, characterized in that, The preheating furnace heating system (2) further includes: a preheating furnace air curtain (212); The preheating furnace air curtain (212) is set at the furnace opening at the front end of the preheating furnace.

5. The multi-waste heat conversion and reuse system for continuous pipe casting production line according to claim 2, characterized in that, The drying oven heating system (3) includes: a low-temperature hot air pipe (301), a high-temperature air pipe (303), a hot flue gas pipe (305), an induced draft fan (306), a main heating pipe (307), and a branch heating pipe (308). The input end of the low-temperature hot air pipe (301) of the drying oven is connected to the preheating oven heating main pipe (208) of the preheating oven heating system (2); The input end of the high-temperature air pipe (303) of the drying oven is connected to the hot air conveying pipeline (6); The drying oven hot flue gas pipe (305) consists of two pipes, and the input ends of the two drying oven hot flue gas pipes (305) are respectively connected to the drying oven exhaust port (309); The output ends of the low-temperature hot air pipe (301) of the drying furnace, the output ends of the high-temperature air pipe (303) of the drying furnace, and the output ends of the two hot flue gas pipes (305) of the drying furnace are connected to the induced draft fan (306) of the drying furnace through the air mixing zone (310); The output end of the drying oven induced draft fan (306) is connected to the drying oven heating main pipe (307); multiple drying oven heating branch pipes (308) are provided on the drying oven heating main pipe (307); multiple drying oven heating branch pipes (308) extend into the drying oven.

6. The continuous pipe production line multi-excess heat conversion and recycling system according to claim 5, characterized in that, The first electric regulating valve (302) of the drying oven is installed on the low-temperature hot air pipe (301); A second electric regulating valve (304) for the drying oven is installed on the high-temperature air pipe (303) of the drying oven.

7. The continuous pipe production line multi-excess heat conversion and recycling system according to claim 1, characterized in that, The drying oven heating system (3) further includes: a drying oven air curtain (311); The air curtain (311) of the drying oven is set at the oven opening at the rear end of the drying oven.

8. The continuous pipe production line multi-excess heat conversion and recycling system according to claim 1, characterized in that, The gas supply system (4) for the health preservation pit includes: a main steam pipe (401) for the health preservation pit and multiple steam branch pipes (406) for the health preservation pit; The steam main pipe (401) of the health preservation pit is connected to the steam transmission pipeline (7); multiple U-shaped anti-expansion pipes (405) are installed on the steam main pipe (401) of the health preservation pit; The steam branch pipe (406) of the health preservation pit is connected to the steam main pipe (401) of the health preservation pit; The steam branch pipe (406) of the health preservation pit enters the bottom of the health preservation pool and penetrates the bottom of the pool. Multiple steam nozzles (407) of the health preservation pit are opened on the steam branch pipe (406).

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