Heat pipe type waste heat recovery system of hot galvanizing furnace kiln

Abstract

According to the heat pipe type waste heat recovery system of the hot galvanizing furnace kiln, soft water enters an expansion water tank, a water inlet of a heat pipe heat exchanger communicates with a water outlet of a circulating water pump, and a water inlet of the circulating water pump communicates with a bottom water outlet of a steam-water separator; a water outlet of the heat pipe heat exchanger is communicated with water inlets of heat exchange pipes in a plating assisting tank and a pickling tank through a tee joint, water outlets of the heat exchange pipes in the plating assisting tank and the pickling tank are communicated with a middle water inlet of a steam-water separator, and a top air outlet of the steam-water separator is communicated with an expansion water tank through an expansion pipe; a hot water outlet pipeline of the heat pipe exchanger communicates with the expansion tank through an exhaust pipe, and an exhaust valve is arranged on the top of the expansion tank. After treatment, the temperature of the flue gas is reduced to about 200 DEG C from about 460 DEG C, the plating assistant solvent is heated to 65-70 DEG C by the recycled heat, and the pickling solution is heated to about 30 DEG C; and a waste heat recovery system is improved, and the energy-saving property and the environment-friendly property are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of hot-dip galvanizing waste heat recovery equipment, in particular to a heat pipe type waste heat recovery system for a hot-dip galvanizing furnace. Background Art

[0002] The process of hot-dip galvanizing is: workpiece → pickling → water washing → dipping in plating solvent → hot-dip galvanizing → cooling → passivation → drying → finishing → inspection.

[0003] Hot-dip galvanizing furnaces are heated by natural gas, which produces a large amount of high-temperature flue gas. Under the current requirements of environmental protection and energy saving, it is necessary to recover the waste heat of the flue gas before discharging it into the atmosphere. Its parameters are as follows: zinc pot size: length 11.0m × width 1.6m × depth 2.8m, auxiliary plating tank size: length 15.1m × width 2.5m × depth 3.0m, zinc pot capacity 306 tons of zinc, plating capacity 12t / h, flue gas temperature about 480℃, flue gas volume about 5150Nm 3 / h.

[0004] Therefore, how to improve the waste heat recovery system and enhance energy saving and environmental protection is a technical problem that technical personnel in this field urgently need to solve. Utility Model Content

[0005] The utility model aims to provide a heat pipe type waste heat recovery system for a hot dip galvanizing furnace.

[0006] In order to solve the above technical problems, the technical solution provided by the utility model is:

[0007] A heat pipe type waste heat recovery system for a hot dip galvanizing furnace, comprising a heat pipe heat exchanger, an expansion water tank, a circulating water pump, a steam-water separator, a heat exchange pipe in a plating auxiliary tank, and a heat exchange pipe in a pickling tank;

[0008] The soft water inlet of the expansion water tank is used to communicate with the water outlet of the soft water pump;

[0009] The smoke inlet of the smoke chamber of the heat pipe heat exchanger is used to communicate with the smoke outlet of the hot-dip galvanizing furnace, and the smoke outlet of the smoke chamber of the heat pipe heat exchanger is used to communicate with the air inlet of the exhaust fan;

[0010] The water inlet of the water chamber of the heat pipe heat exchanger is connected to the water outlet of the circulating water pump through a pipeline, the water inlet of the circulating water pump is connected to the bottom water outlet of the steam-water separator through a pipeline, and the water outlet of the water chamber of the heat pipe heat exchanger is connected to the water inlet of the heat exchange tube in the plating assist tank and the water inlet of the heat exchange tube in the pickling tank through a tee.

[0011] The heat exchange tube in the plating-assisting tank is immersed in the plating-assisting solvent in the plating-assisting tank, and the heat exchange tube in the pickling tank is immersed in the pickling solution in the pickling tank;

[0012] The water outlet of the heat exchange tube in the plating assist tank is connected to the middle water inlet of the steam-water separator through a pipeline, and the water outlet of the heat exchange tube in the pickling tank is connected to the middle water inlet of the steam-water separator through a pipeline;

[0013] The top air outlet of the steam-water separator is communicated with the bottom inlet of the expansion pipe, and the top outlet of the expansion pipe is communicated with the bottom air inlet of the expansion water tank;

[0014] An exhaust port is provided on the top of the hot water outlet pipe connecting the water outlet of the heat pipe heat exchanger and the water inlet of the heat exchange pipe in the plating assist tank, and the exhaust port on the hot water outlet pipe is connected to the top air inlet of the expansion water tank through an exhaust pipe;

[0015] An exhaust valve is arranged on the top of the expansion water tank.

[0016] Preferably, the heat exchange tubes in the plating tank and the heat exchange tubes in the pickling tank are both heat exchange coils made of titanium.

[0017] Preferably, fins are provided on the outer wall of the heat pipe in the heat pipe heat exchanger;

[0018] A water inlet temperature meter for measuring the inlet water temperature is arranged at the water inlet of the heat pipe heat exchanger, and a water outlet temperature meter for measuring the outlet water temperature is arranged at the water outlet of the heat pipe heat exchanger.

[0019] The present application has achieved the following beneficial technical effects:

[0020] According to calculations, after passing through the heat pipe waste heat recovery system, the flue gas temperature of the hot-dip galvanizing furnace drops from about 460°C to about 200°C, and about 512KW of heat is recovered per hour, equivalent to 440,000 kcal; the recovered heat heats the plating solvent in the plating tank to about 65-70°C, and heats the pickling solution in the pickling tank to about 30°C; thereby improving the waste heat recovery system and enhancing energy saving and environmental protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A schematic structural diagram of a heat pipe waste heat recovery system for a hot-dip galvanizing furnace provided in an embodiment of the present application;

[0022] In the figure: 1 heat pipe heat exchanger, 101 flue gas chamber of heat pipe heat exchanger, 102 water chamber of heat pipe heat exchanger, 103 heat pipe in heat pipe heat exchanger, 104 exhaust pipe, 105 water inlet temperature meter, 106 water outlet temperature meter;

[0023] 2 expansion water tank, 201 expansion pipe, 202 exhaust valve on the expansion water tank;

[0024] 3 circulating water pump, 4 steam-water separator;

[0025] 5 plating-assisting tank, heat exchange tube in 501 plating-assisting tank;

[0026] 6 pickling tank, heat exchange tubes in 601 pickling tank. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all of the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0028] In the description of the present invention, it should be understood that the terms "center", "axial", "radial", "longitudinal", "lateral", "length", "width", "up", "down", "front", "back", "left", "right", "top", "bottom", "high", "low", "clockwise", "counterclockwise", "inside", "outside", "horizontal", "vertical" and the like indicate orientations or positional relationships based on orientations or positional relationships in actual use, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0029] Reference Figure 1 , heat pipe heat exchanger 1, flue gas chamber 101 of heat pipe heat exchanger 1, water chamber 102 of heat pipe heat exchanger 1, heat pipe 103 in heat pipe heat exchanger 1, exhaust pipe 104, water inlet temperature gauge 105, water outlet temperature gauge 106; expansion water tank 2, expansion pipe 201, exhaust valve 202 on expansion water tank 2; circulating water pump 3, steam-water separator 4; plating-assisting tank 5, heat exchange tube 501 in plating-assisting tank 5; pickling tank 6, heat exchange tube 601 in pickling tank 6.

[0030] The present application provides a heat pipe waste heat recovery system for a hot-dip galvanizing furnace, comprising a heat pipe heat exchanger 1, an expansion water tank 2, a circulating water pump 3, a steam-water separator 4, a heat exchange pipe in a plating assist tank 5, and a heat exchange pipe in a pickling tank 6;

[0031] The soft water inlet of the expansion water tank 2 is used to communicate with the water outlet of the soft water pump;

[0032] The smoke inlet of the smoke chamber 101 of the heat pipe heat exchanger 1 is used to communicate with the smoke outlet of the hot-dip galvanizing furnace, and the smoke outlet of the smoke chamber 101 of the heat pipe heat exchanger 1 is used to communicate with the air inlet of the exhaust fan;

[0033] The water inlet of the water chamber 102 of the heat pipe heat exchanger 1 is connected to the water outlet of the circulating water pump 3 through a pipeline, the water inlet of the circulating water pump 3 is connected to the bottom water outlet of the steam-water separator 4 through a pipeline, and the water outlet of the water chamber 102 of the heat pipe heat exchanger 1 is connected to the water inlet of the heat exchange tube in the plating assist tank 5 and the water inlet of the heat exchange tube in the pickling tank 6 through a tee.

[0034] The heat exchange tubes in the plating-assisting tank 5 are immersed in the plating-assisting solvent in the plating-assisting tank 5, and the heat exchange tubes in the pickling tank 6 are immersed in the pickling solution in the pickling tank 6;

[0035] The water outlet of the heat exchange tube in the plating assist tank 5 is connected to the middle water inlet of the steam-water separator 4 through a pipeline, and the water outlet of the heat exchange tube in the pickling tank 6 is connected to the middle water inlet of the steam-water separator 4 through a pipeline;

[0036] The top air outlet of the steam-water separator 4 is communicated with the bottom inlet of the expansion pipe 201, and the top outlet of the expansion pipe 201 is communicated with the bottom air inlet of the expansion water tank 2;

[0037] An exhaust port is provided on the top of the hot water outlet pipe connecting the water outlet of the heat pipe heat exchanger 1 and the water inlet of the heat exchange pipe in the plating assist tank 5, and the exhaust port on the hot water outlet pipe is connected to the top air inlet of the expansion water tank 2 through the exhaust pipe 104;

[0038] An exhaust valve 202 is provided on the top of the expansion water tank 2 .

[0039] In one embodiment of the present application, the heat exchange tubes in the plating tank 5 and the heat exchange tubes in the pickling tank 6 are both heat exchange coils made of titanium.

[0040] In one embodiment of the present application, fins are provided on the outer wall of the heat pipe 103 in the heat pipe heat exchanger 1;

[0041] A water inlet temperature meter 105 for measuring the water inlet temperature is provided at the water inlet of the heat pipe heat exchanger 1 , and a water outlet temperature meter 106 for measuring the water outlet temperature is provided at the water outlet of the heat pipe heat exchanger 1 .

[0042] In this application, tap water enters the expansion water tank 2 after automatic soft water purification, and then is injected into the heat pipe heat exchanger 1 by the circulating water pump 3 to produce high-temperature hot water. The zinc pot flue gas enters the heat pipe heat exchanger 1, heats the soft water to above 90°C, and the flue gas temperature drops to about 200°C before being discharged;

[0043] The heated hot water is first pumped into the plating-assisting tank 5, and exchanges heat with the plating-assisting solvent through the heat exchange tube, heating the plating-assisting solvent to 65-70°C, and the temperature of the hot water drops to about 60°C;

[0044] In winter when the ambient temperature is low, the pickling time of plated parts is shortened and production efficiency is improved by exchanging heat with the pickling liquid through heat exchange tubes.

[0045] In the present application, a heat pipe is a heat transfer element that makes full use of the principle of heat conduction and the rapid heat transfer properties of phase change media to quickly transfer the heat of a heating object to the outside of a heat source through the heat pipe, and its thermal conductivity exceeds that of any known metal; the heat pipe is composed of a tube shell, a liquid wick and an end cover, and the inside of the tube is evacuated to a vacuum negative pressure and then filled with an appropriate amount of working liquid, so that the capillary porous material of the liquid wick close to the inner wall of the tube is filled with liquid and then sealed, one end of the tube is an evaporation section (heating section), and the other end is a condensation section (cooling section), and an insulation section is arranged between the two sections.

[0046] In the present application, the heat pipe heat exchanger with heat pipe as heat transfer element has the advantages of high heat transfer efficiency, compact structure, small fluid resistance, and is conducive to controlling dew point corrosion. Heat pipe heat exchangers are divided into integral heat pipe heat exchangers, separate heat pipe heat exchangers, rotary heat pipe heat exchangers, and volute heat pipe heat exchangers according to their forms; according to their functions, heat pipe heat exchangers can be divided into: gas-gas type, gas-steam type, gas-liquid type, liquid-liquid type, and liquid-gas type.

[0047] In the present application, the expansion water tank is generally made of steel plate, usually circular or rectangular; due to the thermal expansion and contraction of water, when the water heats up, the water volume in the system increases. When there is no place to accommodate this part of the expansion of the water, the water pressure increases, which will affect normal operation. At this time, the expansion of the water accommodated by the expansion water tank can reduce the water pressure fluctuation caused by the expansion of the water in the system, thereby improving the safety and reliability of the system operation; when the system leaks for some reason or the system cools down, the water level in the expansion water tank drops to replenish the system; the expansion water tank can also stabilize the pressure of the system and remove the air released by the water during the heating process.

[0048] The methods and devices not described in detail in the present invention are all prior art and will not be described in detail.

[0049] The principles and implementation methods of the present invention are described in this article using specific embodiments. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present invention, the present invention can also be improved and modified, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A heat pipe waste heat recovery system for a hot dip galvanizing furnace, characterized in that: Including heat pipe heat exchanger, expansion water tank, circulating water pump, steam-water separator, heat exchange tube in plating tank, heat exchange tube in pickling tank; The soft water inlet of the expansion water tank is used to communicate with the water outlet of the soft water pump; The smoke inlet of the smoke chamber of the heat pipe heat exchanger is used to communicate with the smoke outlet of the hot-dip galvanizing furnace, and the smoke outlet of the smoke chamber of the heat pipe heat exchanger is used to communicate with the air inlet of the exhaust fan; The water inlet of the water chamber of the heat pipe heat exchanger is connected to the water outlet of the circulating water pump through a pipeline, the water inlet of the circulating water pump is connected to the bottom water outlet of the steam-water separator through a pipeline, and the water outlet of the water chamber of the heat pipe heat exchanger is connected to the water inlet of the heat exchange tube in the plating assist tank and the water inlet of the heat exchange tube in the pickling tank through a tee. The heat exchange tube in the plating-assisting tank is immersed in the plating-assisting solvent in the plating-assisting tank, and the heat exchange tube in the pickling tank is immersed in the pickling solution in the pickling tank; The water outlet of the heat exchange tube in the plating assist tank is connected to the middle water inlet of the steam-water separator through a pipeline, and the water outlet of the heat exchange tube in the pickling tank is connected to the middle water inlet of the steam-water separator through a pipeline; The top air outlet of the steam-water separator is communicated with the bottom inlet of the expansion pipe, and the top outlet of the expansion pipe is communicated with the bottom air inlet of the expansion water tank; An exhaust port is provided on the top of the hot water outlet pipe connecting the water outlet of the heat pipe heat exchanger and the water inlet of the heat exchange pipe in the plating assist tank, and the exhaust port on the hot water outlet pipe is connected to the top air inlet of the expansion water tank through an exhaust pipe; An exhaust valve is arranged on the top of the expansion water tank.

2. The heat pipe waste heat recovery system for a hot dip galvanizing furnace according to claim 1, characterized in that: The heat exchange tubes in the plating tank and the heat exchange tubes in the pickling tank are both heat exchange coils made of titanium.

3. The heat pipe waste heat recovery system for a hot dip galvanizing furnace according to claim 1, characterized in that: The outer wall of the heat pipe in the heat pipe heat exchanger is provided with fins; A water inlet temperature meter for measuring the inlet water temperature is arranged at the water inlet of the heat pipe heat exchanger, and a water outlet temperature meter for measuring the outlet water temperature is arranged at the water outlet of the heat pipe heat exchanger.

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