Tunnel kiln flue gas waste heat recovery device

Abstract

The utility model provides a tunnel kiln flue gas waste heat recovery device which comprises heat exchange equipment laid on the top of a firing zone, an exhaust pipe, a fresh air header pipe and a plurality of fresh air branch pipes, and a hot air flow channel and a fresh air flow channel are arranged in the heat exchange equipment. The input end of the exhaust pipe communicates with the top of the preheating zone, the output end of the exhaust pipe communicates with a hot air inlet of the hot air flow channel, an exhaust fan is arranged on the exhaust pipe, and a hot air outlet of the hot air flow channel communicates with an air outlet pipe. The fresh air flow channel is provided with a fresh air inlet communicated with the output end of the fresh air main pipe and a plurality of fresh air outlets communicated with the input ends of the fresh air branch pipes in a one-to-one correspondence mode, an air blower is arranged on the fresh air main pipe, the fresh air branch pipes are evenly arranged on the two sides of the firing zone, and the output end of each fresh air branch pipe is communicated with the side face of the firing zone. The flue gas waste heat recovery device for the tunnel kiln has the advantages that waste heat can be introduced into a firing zone for combustion supporting, and therefore the fuel consumption is reduced on the premise that production is not affected.

Description

TECHNICAL FIELD

[0001] The utility model relates to tunnel kiln technical field, specifically, relate to a tunnel kiln flue gas waste heat recovery device. BACKGROUND

[0002] Tunnel kiln is usually composed of preheating zone, firing zone and cooling zone, the kiln body is long strip tunnel, the bottom is paved with track for kiln car walking, and the both sides of firing zone are provided with combustion equipment, when using, firing zone produces high temperature by burning natural gas, coal gas or oil fuel, the kiln car loads the blank and enters from the entrance of preheating zone, and the cold air is blown from the kiln tail of cooling zone, the blank is preheated by the high temperature flue gas of firing zone first, then reaches the highest point in firing zone, completes sintering, and finally is cooled by the cold air in cooling zone, and the cold air is heated at the same time, plays the combustion supporting role.

[0003] Because the flue gas temperature in tunnel kiln is very high, directly discharging undoubtedly wastes a large amount of heat, the common waste heat recovery mode of existing tunnel kiln mainly has: extracting preheating zone flue gas to drying chamber, drying and preheating the blank, installing water tank on the kiln top, using the radiation heating of kiln to heat cold water, for production use or worker bath, introducing high temperature flue gas into boiler, for central heating etc., but these modes all recover the heat produced by kiln body, cannot reduce the fuel consumption from the source.

[0004] In order to solve the above problems, people have been seeking an ideal technical solution. SUMMARY

[0005] The utility model aims at the deficiency of prior art, and provides a tunnel kiln flue gas waste heat recovery device that can introduce waste heat into firing zone to support combustion, thereby reducing fuel consumption without affecting production and improving energy efficiency.

[0006] In order to achieve the above object, the technical scheme adopted by the utility model is: a tunnel kiln flue gas waste heat recovery device, the tunnel kiln comprises a preheating zone, a firing zone and a cooling zone which extend along the longitudinal direction, a plurality of combustion equipment is arranged on both sides of the firing zone, the tunnel kiln flue gas waste heat recovery device comprises heat exchange equipment, an air extraction pipe, a fresh air main pipe and a plurality of fresh air branch pipes which are laid on the top of the firing zone, the heat exchange equipment is internally provided with hot air flow channels and fresh air flow channels which are used for heat exchange; the input end of the air extraction pipe is communicated with the top of the preheating zone, and the output end is communicated with the hot air inlet of the hot air flow channels, an air extractor is arranged on the air extraction pipe, and the hot air outlet of the hot air flow channels is communicated with an air outlet pipe; the fresh air flow channels are provided with a fresh air inlet which is communicated with the output end of the fresh air main pipe and a plurality of fresh air outlets which are communicated with the input ends of the plurality of fresh air branch pipes one by one, an air blower is arranged on the fresh air main pipe, and the plurality of fresh air branch pipes are uniformly arranged on both sides of the firing zone, and the output end of each fresh air branch pipe is communicated with the side surface of the firing zone.

[0007] Beneficial effects: the air extraction pipe extracts high-temperature flue gas in the preheating zone into the hot air flow channels, the fresh air main pipe blows fresh air into the fresh air flow channels, and the high-temperature flue gas and the fresh air complete heat exchange in the heat exchange equipment, meanwhile, the heat exchange equipment can also absorb part of the heat radiated by the firing zone, so that heat recovery is realized, the heated fresh air enters the firing zone through the plurality of fresh air branch pipes, the oxygen content in the fresh air is high, and the fresh air can play a combustion-supporting role, thereby reducing the fuel consumption without affecting the production.

[0008] Based on the above, the heat exchange equipment comprises a horizontal heat exchange box in the shape of a cuboid and a plurality of longitudinal heat exchange pipes, two transverse partitions are arranged in the horizontal heat exchange box, the horizontal heat exchange box is sequentially divided into a hot air distribution cavity, the fresh air flow channels and a hot air collection cavity by the two transverse partitions, each longitudinal heat exchange pipe is arranged in the fresh air flow channels and penetrates the two transverse partitions at both ends, the hot air inlet is arranged on the hot air distribution cavity, the hot air outlet is arranged on the hot air collection cavity, and the hot air distribution cavity, the plurality of longitudinal heat exchange pipes and the hot air collection cavity jointly form the hot air flow channels.

[0009] Beneficial effects: the horizontal heat exchange box is better attached to the top of the firing zone, and can more easily absorb the heat radiated by the firing zone, the hot air distribution cavity plays a role of hot air distribution, the hot air collection cavity plays a role of hot air collection, and the two are integrated at both ends of the fresh air flow channels, so that the external pipeline structure can be simplified on the one hand, and the heat exchange effect can be improved on the other hand.

[0010] Based on the above, the fresh air flow channel is further provided with two longitudinal partitions, the two longitudinal partitions separate the fresh air flow channel into a fresh air buffer cavity in the middle and fresh air heat exchange cavities on both sides, the output end of the fresh air main pipe is communicated at the top of the fresh air buffer cavity, a plurality of air holes are uniformly arranged on the two longitudinal partitions, and a plurality of longitudinal heat exchange pipes are symmetrically distributed in the two fresh air heat exchange cavities.

[0011] Beneficial effects: the fresh air buffer cavity helps the fresh air to be more evenly distributed in the fresh air heat exchange cavities, and the fresh air flow channel is separated into the fresh air buffer cavity in the middle and the fresh air heat exchange cavities on both sides by the two longitudinal partitions, so that the heat exchange equipment is compact in structure and convenient to install.

[0012] Based on the above, the outer side of the plurality of longitudinal heat exchange pipes is provided with heat dissipation fins extending in the transverse direction.

[0013] Beneficial effects: the heat dissipation area is increased, and the heat exchange effect of the hot air and the fresh air is further improved.

[0014] Based on the above, the output ends of the plurality of fresh air branch pipes are staggered with the positions of the plurality of combustion equipment.

[0015] Beneficial effects: the fresh air and the fuel are mixed more evenly, and the combustion effect is better. BRIEF DESCRIPTION OF DRAWINGS

[0016] Fig. 1 is a side structure schematic view of the tunnel kiln flue gas waste heat recovery device in the utility model.

[0017] Fig. 2 is a top view of the heat exchange equipment.

[0018] Fig. 3 is a schematic view of the internal structure of the heat exchange equipment.

[0019] In the drawing: 1. preheating zone; 2. sintering zone; 3. cooling zone; 4. combustion equipment; 5. heat exchange equipment; 6. air extraction pipe; 7. fresh air main pipe; 8. fresh air branch pipe; 9. air extractor; 10. air outlet pipe; 11. air blower; 12. hot air distribution cavity; 13. hot air collection cavity; 14. fresh air buffer cavity; 15. fresh air heat exchange cavity; 16. heat dissipation fin; 51. horizontal heat exchange box; 52. longitudinal heat exchange pipe; 53. transverse partition; 54. longitudinal partition; 55. air hole. DETAILED DESCRIPTION

[0020] The technical scheme of the utility model will be described in further detail below through specific embodiments.

[0021] As Figs. 1-3As shown, a tunnel kiln flue gas waste heat recovery device, the tunnel kiln includes a preheating zone 1, firing zone 2 and cooling zone 3 along the longitudinal extension, the firing zone 3 both sides are provided with several combustion equipment 4, the above is the common tunnel kiln in the prior art.

[0022] The tunnel kiln flue gas waste heat recovery device includes laying in the top of the firing zone 2 heat exchange equipment 5, exhaust pipe 6, fresh air main pipe 7 and several fresh air branch pipe 8, the heat exchange equipment 5 is provided with hot air flow channel and fresh air flow channel for heat exchange.

[0023] The input end of the exhaust pipe 6 is communicated with the top of the preheating zone 1, the output end is communicated with the hot air inlet of the hot air flow channel, the exhaust fan 9 is arranged on the exhaust pipe 6, the hot air outlet of the hot air flow channel is communicated with the air outlet pipe 10, the high temperature flue gas in the preheating zone 1 is sucked into the hot air flow channel by the exhaust fan 9, and the hot air outlet pipe 10 is discharged after heat exchange.

[0024] The fresh air flow channel is provided with a fresh air inlet communicated with the output end of the fresh air main pipe 7 and a plurality of fresh air outlets communicated with the input end of the plurality of fresh air branch pipes 8 one by one, the air blower 11 is arranged on the fresh air main pipe 7, and the plurality of fresh air branch pipes 8 are uniformly arranged on the two sides of the firing zone 1. The output end of each of the fresh air branch pipes 8 is communicated with the side of the firing zone 1, the air blower 11 blows fresh air into the fresh air flow channel, and after heat exchange, the fresh air enters the two sides of the firing zone 1 from the plurality of fresh air branch pipes 8, which plays a role in combustion support.

[0025] In order to further improve the heat exchange effect, the heat exchange equipment includes a horizontal heat exchange box 51 in the shape of a rectangular parallelepiped and a plurality of longitudinal heat exchange pipes 52, two transverse partitions 53 are arranged in the horizontal heat exchange box 51, and the horizontal heat exchange box 51 is sequentially divided into a hot air distribution chamber 12, the fresh air flow channel and a hot air collection chamber 13 by the two transverse partitions 53. Each of the longitudinal heat exchange pipes 52 is arranged in the fresh air flow channel and penetrates the two transverse partitions 53 at both ends, the hot air inlet is arranged on the hot air distribution chamber 12, and the hot air outlet is arranged on the hot air collection chamber 13. The hot air distribution chamber 12, the plurality of longitudinal heat exchange pipes 52 and the hot air collection chamber 13 jointly form the hot air flow channel. The horizontal heat exchange box 51 is better attached to the top of the firing zone 2, and is easy to absorb the heat radiated by the firing zone 2. The hot air distribution chamber 12 plays a role in hot air distribution, and the hot air collection chamber 13 plays a role in hot air collection. The two ends of the fresh air flow channel are integrated to form a "surrounding" structure, which not only simplifies the external pipeline structure, but also improves the heat exchange effect.

[0026] The new air flow channel is further provided with two longitudinal partitions 54, which divide the new air flow channel into a new air buffer cavity 14 in the middle and two new air heat exchange cavities 15 on the two sides, the output end of the new air main pipe 7 is communicated to the top of the new air buffer cavity 14, a plurality of air holes 55 are uniformly arranged on the two longitudinal partitions 54, and a plurality of longitudinal heat exchange pipes 52 are symmetrically arranged in the two new air heat exchange cavities 15, the new air buffer cavity 14 helps the new air to be more uniformly distributed in the new air heat exchange cavities 15, and the two longitudinal partitions 54 are used for division, so that the heat exchange equipment 5 is compact in structure and convenient to install.

[0027] In addition, the outer side of the plurality of longitudinal heat exchange pipes 52 is provided with heat dissipation fins 16 extending in the transverse direction, so that the heat exchange area is increased, and the heat exchange effect of the hot air and the new air is further improved.

[0028] In other embodiments, the output ends of the several new air branch pipes 8 and the positions of the several combustion equipment 4 can also be staggered, so that the new air and the fuel are mixed more uniformly, and the combustion supporting effect is better.

[0029] Working principle:

[0030] The air suction fan 9 is started, the air suction pipe 6 sucks the high-temperature flue gas in the preheating zone 1 into the hot air flow channel, the air blower 11 is started, the new air main pipe 7 blows fresh air into the new air flow channel, the high-temperature flue gas and the fresh air complete heat exchange in the heat exchange equipment 5, at the same time, the heat exchange equipment 5 can also absorb part of the heat radiated by the firing zone, so as to realize heat recovery, the heated fresh air enters the firing zone 2 through the several new air branch pipes 8, the oxygen content in the fresh air is high, so as to play a good combustion supporting effect, and then realize the internal circulation of heat, reduce the fuel consumption under the premise of not affecting the production.

[0031] Finally, it should be noted that: the above embodiments are only used to illustrate the technical scheme of the present application, but not to limit it; although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the specific embodiments of the present application can be modified or some technical features can be replaced by equivalent ones; without departing from the spirit of the technical scheme of the present application, they should be covered in the technical scheme range of the present application claimed to be protected.

Claims

1. A waste heat recovery device for flue gas from a tunnel kiln, the tunnel kiln comprising a preheating zone, a firing zone, and a cooling zone extending longitudinally, wherein a plurality of combustion devices are arranged on both sides of the firing zone, characterized in that: The waste heat recovery device for flue gas from the tunnel kiln includes a heat exchange device, an exhaust duct, a main fresh air duct, and several branch fresh air ducts laid on top of the firing zone. The heat exchange device is equipped with a hot air flow channel and a fresh air flow channel for heat exchange. The input end of the exhaust duct is connected to the top of the preheating zone, and the output end is connected to the hot air inlet of the hot air flow channel. An exhaust fan is installed on the exhaust duct, and the hot air outlet of the hot air flow channel is connected to an air outlet duct. The fresh air flow channel is equipped with a fresh air inlet connected to the output end of the main fresh air duct and multiple fresh air outlets connected to the input ends of the branch fresh air ducts. A blower is installed on the main fresh air duct, and the branch fresh air ducts are evenly arranged on both sides of the firing zone. The output end of each branch fresh air duct is connected to the side of the firing zone.

2. The tunnel kiln flue gas waste heat recovery device according to claim 1, characterized in that: The heat exchange equipment includes a rectangular horizontal heat exchange box and multiple longitudinal heat exchange tubes. The horizontal heat exchange box is equipped with two transverse partitions, which sequentially divide the horizontal heat exchange box into a hot air distribution chamber, a fresh air flow channel, and a hot air collection chamber. Each of the longitudinal heat exchange tubes passes through the fresh air flow channel and penetrates both of the transverse partitions at both ends. The hot air inlet is located on the hot air distribution chamber, and the hot air outlet is located on the hot air collection chamber. The hot air distribution chamber, the multiple longitudinal heat exchange tubes, and the hot air collection chamber together form the hot air flow channel.

3. The waste heat recovery device for tunnel kiln flue gas according to claim 2, characterized in that: Two longitudinal partitions are also provided in the middle of the fresh air flow channel. The two longitudinal partitions divide the fresh air flow channel into a middle fresh air buffer chamber and two sides of fresh air heat exchange chambers. The output end of the fresh air main pipe is connected to the top of the fresh air buffer chamber. Multiple ventilation holes are evenly opened on the two longitudinal partitions. Multiple longitudinal heat exchange pipes are symmetrically distributed in the two fresh air heat exchange chambers.

4. The tunnel kiln flue gas waste heat recovery device according to claim 3, characterized in that: Multiple longitudinal heat exchange tubes are provided with heat dissipation fins that extend laterally on their outer sides.

5. The tunnel kiln flue gas waste heat recovery device according to any one of claims 1-4, characterized in that: The output ends of several of the fresh air branch pipes are arranged alternately with the positions of several of the combustion devices.

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