Ultra-low-temperature flue gas emission device for steel rolling heating furnace

Abstract

The utility model discloses a flue gas ultralow-temperature emission device for a steel rolling heating furnace, which belongs to the technical field of high-temperature flue gas treatment of heating furnaces and comprises a chimney for flue gas emission and two spiral support strips relatively fixed in the chimney. The spiral pipe is arranged on the spiral supporting strip in a threaded mode, the flow deflectors are fixed to the spiral pipe, and the upper circulation assembly is used for conveying chilled water in a closed-loop mode. The upper circulating assembly and the lower circulating assembly are arranged in the chimney for cooperative use, refrigerating fluid output by the hot water type absorption unit is heated through heat of flue gas, the flue gas can be preliminarily cooled, the hot water type absorption unit can be driven to operate, and cooling capacity is generated; and the flue gas in the chimney is forcibly cooled for the second time by using the cold energy generated by the hot water type absorption unit, so that the cooling effect on the flue gas is further improved.

Description

Technical Field

[0001] The utility model relates to the technical field of high-temperature flue gas treatment in heating furnaces, in particular to an ultra-low temperature flue gas emission device for steel rolling heating furnaces. Background Art

[0002] The existing steel rolling process in the metallurgical industry mainly uses blast furnace and converter gas combustion to generate high temperatures to heat the steel billets and at the same time produce a large amount of high-temperature flue gas, which is forced to be exhausted through induced draft fans, resulting in a large amount of waste of high-temperature flue gas energy. To solve the above problems, in recent years, plate heat exchangers plus cooling towers and air preheaters have been mainly used to partially recover energy. However, they are limited to the energy waste of heat caused by cooling towers and the specific heat capacity of air. Although some high-temperature flue gas is solved, the emission temperature is still 300°C, which is still substandard and has a significant impact on the flue gas emission efficiency. Utility Model Content

[0003] The purpose of the utility model is to provide an ultra-low temperature flue gas emission device for a steel rolling heating furnace, so as to solve the problem in the above background technology that the emission temperature is difficult to meet the standard and has a great impact on the emission efficiency of the flue gas.

[0004] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0005] The utility model provides a device for discharging flue gas from a steel rolling heating furnace at a very low temperature, comprising a chimney for discharging flue gas, and further comprising:

[0006] Two spiral support bars are relatively fixed in the chimney.

[0007] A spiral tube is threadedly arranged on the spiral supporting strip.

[0008] A plurality of guide plates are fixed on the spiral tube.

[0009] Upper circulation components for closed-loop chilled water delivery.

[0010] Lower circulation assembly for closed-loop transfer of refrigerant.

[0011] A hot water absorption unit is provided at the terminals of the upper circulation component and the lower circulation component.

[0012] Furthermore, the guide vanes are in a spiral twisted shape, and a plurality of guide vanes are distributed on the spiral tube along the spiral line of the spiral tube.

[0013] Furthermore, the lower circulation component includes:

[0014] A lower three-way valve and a one-way valve are provided at both ends of one of the spiral tubes.

[0015] A water supply return pipe is provided on the lower three-way valve, and one end of the water supply return pipe is fixed on the refrigerant return port of the hot water absorption unit.

[0016] A butt joint pipe is provided at the input end of the one-way valve, and a lower three-way valve is also provided at one end of the butt joint pipe.

[0017] A hot water circulation pump is provided at the refrigeration liquid output end of the hot water absorption unit.

[0018] A water inlet pipe is provided between the output end of the hot water circulation pump and one of the lower three-way valves.

[0019] Furthermore, the one-way valve and the lower three-way valve are both located outside the chimney, and the remaining ends of the two lower three-way valves are respectively provided with a vaporized cooling hot water return pipe and a vaporized cooling hot water inlet pipe.

[0020] Furthermore, the upper circulation component includes:

[0021] Upper three-way valves are provided at both ends of the other spiral tube.

[0022] A chilled water return pipe and a chilled water outlet pipe are respectively arranged at one end of the two upper three-way valves, and one end of the chilled water return pipe is fixed to the chilled water return end of the hot water absorption unit.

[0023] A chilled water circulation pump is provided between one end of the chilled water outlet pipe and the chilled water output end of the hot water absorption unit.

[0024] Furthermore, the upper circulation component also includes a cold transport pipe for transporting excess cold, and one end of the cold transport pipe is arranged at the remaining end of one of the upper three-way valves.

[0025] Compared with the existing technology, one or more of the above technical solutions have the following beneficial effects:

[0026] 1. This utility model uses the heat of the flue gas to heat the refrigerant output by the hot water absorption unit by arranging upper and lower circulation components in the chimney. This not only provides preliminary cooling of the flue gas, but also drives the hot water absorption unit to operate and generate cooling energy. The cooling energy generated by the hot water absorption unit is then used to perform secondary forced cooling of the flue gas in the chimney, further improving the cooling effect of the flue gas.

[0027] 2. The utility model forms multiple groups of spirally twisted guide strips in the circumferential direction of the chimney through a number of spirally distributed guide strips and its own spiral twisting, which can not only increase the basic area with the flue gas and improve the heat exchange efficiency, but also reduce the influence of the guide strips on the flue gas circulation efficiency in the chimney, thereby affecting the operation of the furnace. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is an axonometric drawing of the present utility model;

[0029] Figure 2 It is a partial sectional axonometric drawing of the present utility model;

[0030] Figure 3 It is a half-section axonometric drawing of the chimney in the present invention.

[0031] In the figure: 1. Chimney; 2. Spiral pipe; 3. Guide vane; 4. Upper circulation assembly; 41. Upper three-way valve; 42. Chilled water return pipe; 43. Chilled water outlet pipe; 44. Chilled water circulation pump; 5. Lower circulation assembly; 51. Lower three-way valve; 52. Water supply return pipe; 53. One-way valve; 54. Butt joint pipe; 55. Water inlet pipe; 56. Hot water circulation pump; 6. Hot water absorption unit; 7. Spiral support bar. DETAILED DESCRIPTION

[0032] In order to enable people skilled in the art to better understand the solution of the present application, the technical solution in the embodiment of the present application will be clearly and completely described below in conjunction with the drawings in the embodiment of the present application.

[0033] like Figures 1 to 3 As shown, a device for discharging flue gas from a steel rolling heating furnace at a very low temperature comprises a chimney 1 for discharging flue gas, and the device for discharging flue gas from a steel rolling heating furnace at a very low temperature further comprises:

[0034] Two spiral support bars 7 are fixed relatively to each other in the chimney 1 .

[0035] The spiral tube 2 is threadedly mounted on the spiral support strip 7 .

[0036] A plurality of guide plates 3 are fixed on the spiral tube 2.

[0037] Upper circulation component 4 for closed-loop transportation of chilled water.

[0038] The lower circulation component 5 is used for closed-loop transportation of the refrigerant.

[0039] A hot water absorption unit 6 is provided at the terminals of the upper circulation component 4 and the lower circulation component 5.

[0040] like Figures 1 to 3As shown, in this embodiment, the guide plate 3 is spirally twisted, and the materials of the guide plate 3 and the spiral tube 2 are both high-temperature resistant and have good heat conduction effects, and a number of guide plates 3 are distributed on the spiral tube 2 along the spiral line of the spiral tube 2, with the bottom ends of two adjacent guide plates 3 corresponding to each other, so that a number of guide plates 3 can be connected to form multiple groups of open-loop guide strips. Such a design can not only increase the contact area between the guide plate 3 and the high-temperature flue gas and improve the heat exchange efficiency, but also reduce the obstruction of the guide plate 3 to the discharge of the high-temperature flue gas, avoid the retention of flue gas in the chimney and affect the discharge efficiency of the flue gas, and transfer the waste heat in the flue gas to the spiral tube 2 by heat conduction, and use the waste heat to heat the liquid flowing in the spiral tube 2 to achieve waste heat recovery and utilization, and can achieve a flue gas cooling effect in the process of waste heat recovery, reduce the temperature of the flue gas when it is discharged from the chimney, so that its discharge temperature can reach the discharge standard temperature, and avoid the problem of thermal pollution.

[0041] like Figure 2 and Figure 3 As shown, in this embodiment, the lower circulation component 5 includes:

[0042] A lower three-way valve 51 and a one-way valve 53 are provided at both ends of one of the spiral tubes 2 .

[0043] A water supply return pipe 52 is provided on the lower three-way valve 51 , and one end of the water supply return pipe 52 is fixed to the refrigerant return port of the hot water absorption unit 6 .

[0044] A butt joint pipe 54 is provided at the input end of the one-way valve 53 , and a lower three-way valve 51 is also provided at one end of the butt joint pipe 54 .

[0045] A hot water circulation pump 56 is provided at the refrigerant liquid output end of the hot water absorption unit 6 .

[0046] The water inlet pipe 55 arranged between the output end of the hot water circulation pump 56 and one of the lower three-way valves 51 controls the circulation state of the refrigerant in the lower circulation component 5 through the lower three-way valve 51 and the one-way valve 53, and can control the hydraulic pressure in the spiral tube 2 through the one-way valve 53 to avoid the problem of refrigerant reflux caused by the output pressure of the hot water circulation pump 56 being less than the hydraulic pressure in the spiral tube 2, so that the refrigerant can circulate in the closed-loop circulation system composed of the hot water absorption unit 6, the lower circulation component 5 and one of the spiral tubes 2, and the spiral tube 2 in which the refrigerant flows is located at the bottom end of the chimney 1. During the flue gas discharge process, the heat carried by the flue gas at the bottom end of the chimney 1 is greater than the heat carried by the flue gas at the top end of the chimney 1, which can provide sufficient heat for the heating of the refrigerant and make the temperature of the refrigerant reach the temperature for driving the hot water absorption unit 6 to operate, so that the hot water absorption unit 6 generates cooling energy and can initially reduce the temperature of the flue gas.

[0047] like Figure 2 and Figure 3 As shown, in this embodiment, the one-way valve 53 and the lower three-way valve 51 are both located outside the chimney 1, and the remaining ends of the two lower three-way valves 51 are respectively provided with a vaporized cooling hot water return pipe and a vaporized cooling hot water inlet pipe. The heat absorption, collection, transportation and release application process are realized through the change of the liquid form, and the collected excess heat can be transported to other equipment that requires heat, thereby improving the utilization rate of flue gas waste heat and reducing energy use costs.

[0048] like Figure 2 and Figure 3 As shown, in this embodiment, the upper circulation component 4 includes:

[0049] The upper three-way valves 41 are provided at both ends of the other spiral tube 2 .

[0050] A chilled water return pipe 42 and a chilled water outlet pipe 43 are respectively provided at one end of the two upper three-way valves 41 , and one end of the chilled water return pipe 42 is fixed to the chilled water return end of the hot water absorption unit 6 .

[0051] A chilled water circulation pump 44 is provided between one end of the chilled water outlet pipe 43 and the chilled water output end of the hot water absorption unit 6, the upper circulation component 4, the hot water absorption unit 6 and the spiral tube 2 located at the top inner side of the chimney 1 to form a closed-loop circulation system. The cold energy generated by the hot water absorption unit 6 during operation will flow into the spiral tube 2 located at the top inner side of the chimney 1 through the conveying method of chilled water, thereby achieving continuous secondary forced cooling of the flue gas, further improving the cooling effect of the flue gas, making the final emission temperature of the flue gas lower than the standard flue gas emission temperature, avoiding the problem of thermal pollution in the flue gas emission, and improving the environmental protection effect.

[0052] like Figure 2 and Figure 3 As shown, in this embodiment, the upper circulation component 4 also includes a cold transport pipe for transporting excess cold. One end of the cold transport pipe is arranged at the remaining end of one of the upper three-way valves 41. The cold transport pipe can transport the excess cold generated when the hot water absorption unit 6 is in operation to the place where cold is needed, thereby improving resource utilization, reducing resource waste, and saving energy expenditure costs.

[0053] Working principle: When the flue gas is discharged, the hot water circulation pump 56 and the chilled water circulation pump 44 are started to transport the refrigerant in the hot water absorption unit 6 through the water inlet pipe, one of the lower three-way valves 51, the butt pipe 54 and the one-way valve 53 to the spiral tube 2 at the bottom end of the chimney 1. The refrigerant enters from the bottom end of the spiral tube 2 and is discharged from the top end of the spiral tube 2. During the flow of the refrigerant in the spiral tube 2, the guide plate 3 will transfer part of the waste heat of the flue gas to the spiral tube 2 by heat transfer, so that the heat exchange between the flue gas and the refrigerant is completed, and the waste heat of the flue gas is used to heat the refrigerant. The heated refrigerant is transported back to the hot water absorption unit 6 through the water supply return pipe 52, so that the heated refrigerant drives the hot water absorption unit 6 to operate. The chilled water circulation pump 44 can transport the cooling capacity generated by the hot water absorption unit 6 in the form of chilled water through the chilled water outlet pipe 43 and one of the upper three-way valves 41 to the spiral tube 2 located at the top of the chimney 1, and realize the heat exchange between the chilled water and the flue gas through the guide plate 3, thereby realizing the secondary forced cooling of the flue gas and further improving the cooling effect of the flue gas.

[0054] The above description is merely a preferred embodiment of the present invention. Any portion not described in the present invention can be implemented by adopting or drawing upon existing technologies. Of course, the above description is not intended to limit the present invention, nor is the present invention limited to the above examples. Any changes, modifications, additions, or substitutions made by those skilled in the art within the spirit and scope of the present invention shall also fall within the scope of protection of the present invention.

Claims

1. A device for ultra-low temperature exhaust of flue gas from a steel rolling heating furnace, comprising a chimney (1) for exhausting flue gas, characterized in that: The ultra-low temperature exhaust device for flue gas from a steel rolling heating furnace also includes: Two spiral support bars (7) fixed relatively to the chimney (1); A spiral tube (2) having threads arranged on the spiral support strip (7); A plurality of guide vanes (3) fixed on the spiral tube (2); An upper circulation assembly (4) for closed-loop delivery of chilled water; A lower circulation assembly (5) for closed-loop delivery of refrigerant; A hot water absorption unit (6) is provided at the terminals of the upper circulation component (4) and the lower circulation component (5).

2. The ultra-low temperature exhaust device for flue gas from a steel rolling heating furnace according to claim 1 is characterized in that: The guide vane (3) is in a spiral twisted shape, and a plurality of guide vanes (3) are distributed on the spiral tube (2) along the spiral line of the spiral tube (2).

3. The ultra-low temperature exhaust device for flue gas from a steel rolling heating furnace according to claim 1 is characterized in that: The lower circulation component (5) comprises: A lower three-way valve (51) and a one-way valve (53) provided at both ends of one of the spiral tubes (2); a water supply return pipe (52) provided on the lower three-way valve (51), one end of the water supply return pipe (52) being fixed to the refrigerant return port of the hot water absorption unit (6); A butt-joint pipe (54) provided at the input end of the one-way valve (53), wherein a lower three-way valve (51) is also provided at one end of the butt-joint pipe (54); a hot water circulation pump (56) provided at the refrigerant liquid output end of the hot water absorption unit (6); A water inlet pipe (55) is provided between the output end of the hot water circulation pump (56) and one of the lower three-way valves (51).

4. The ultra-low temperature exhaust device for flue gas from a steel rolling heating furnace according to claim 3 is characterized in that: The one-way valve (53) and the lower three-way valve (51) are both located outside the chimney (1), and the remaining ends of the two lower three-way valves (51) are respectively provided with a vaporized cooling hot water return pipe and a vaporized cooling hot water inlet pipe.

5. The ultra-low temperature exhaust device for steel rolling heating furnace flue gas according to claim 1 is characterized in that: The upper circulation component (4) comprises: Upper three-way valves (41) provided at both ends of the other spiral tube (2); A chilled water return pipe (42) and a chilled water outlet pipe (43) respectively arranged at one end of the two upper three-way valves (41), one end of the chilled water return pipe (42) being fixed to the chilled water return end of the hot water absorption unit (6); A chilled water circulation pump (44) is provided between one end of the chilled water outlet pipe (43) and the chilled water output end of the hot water absorption unit (6).

6. The ultra-low temperature exhaust device for steel rolling heating furnace flue gas according to claim 5 is characterized in that: The upper circulation component (4) further comprises a cold transport pipe for transporting excess cold, one end of the cold transport pipe being arranged at the remaining end of one of the upper three-way valves (41).

Images