Cold-pressed pellet drying equipment and method thereof

Abstract

The invention relates to cold-pressed pellet drying equipment and a method thereof.The cold-pressed pellet drying equipment comprises a mesh belt machine, a hot air drying smoke hood, a dry smoke circulating system, a finished product sealing-tape machine, an air bellow, a double-layer cinder valve, a bulk material sealing-tape machine, a drying section I externally-exhausted smoke pipeline, a wet desulphurization device, an externally-exhausted smoke induced draft fan, a silencer and a chimney, and the mesh belt machine is arranged in the hot air drying smoke hood; an air bellow is arranged below the hot air drying smoke hood, a double-layer cinder valve is arranged below the air bellow, a bulk material sealing-tape machine is arranged below the double-layer cinder valve, the hot air drying smoke hood is divided into a drying section I and a drying section II, the drying section I and the drying section II are connected with a drying smoke circulating system, and a drying section I exhaust smoke pipeline is arranged at the bottom of the drying section I; the wet desulphurization device and the wet dust collector are connected with a chimney through an exhaust flue gas induced draft fan via a silencer. The wet desulphurization device and the wet dust collector have the beneficial effects that the energy consumption is reduced, the fuel consumption per ton of balls is low, the fuel utilization rate is high, the operation energy consumption is low, the pollution discharge amount is low, and the energy-saving and emission-reducing effects are good.

Description

Technical Field

[0001] The invention relates to the technical field of cold-pressed pellet drying, and in particular to a cold-pressed pellet drying device and a method thereof. Background Art

[0002] Cold pressed pellets need to be dried before they can reach the predetermined strength, so a short process flow, stable and reliable equipment, and a drying system and equipment with high thermal efficiency are particularly important for the development of cold pressed pellet technology.

[0003] The existing cold-pressed pellet drying technology has the following defects and shortcomings: 1) At present, a low-temperature chain grate machine is used to dry cold-pressed pellets. The equipment has a large investment, high professionalism and large maintenance workload, and the maintenance personnel have a large workload and low work efficiency; 2) The hot air in the hot air furnace that provides heat for the drying equipment is directly discharged after passing through the drying equipment, and the flue gas thermal energy utilization rate is low, the flue gas emissions are large, the pollution is serious, the fuel consumption per ton of pellets is high, and the energy consumption is huge; 3) The exhaust gas is centrally treated. In order to meet the temperature requirements of denitrification and dust removal, the exhaust gas needs to be heated twice, which makes the flue gas treatment difficult and greatly wastes fuel. Summary of the invention

[0004] In order to overcome the shortcomings of the prior art, the present invention provides a cold-pressed pellet drying device and method thereof, wherein the high-temperature flue gas at the bottom of drying stage II is reintroduced into drying stage I for preheating and drying through a drying flue gas circulation system, thereby improving the thermal energy utilization rate of the flue gas, and the secondary air from the high-temperature area of ​​drying stage I and the low-temperature area of ​​drying stage II is introduced into a hot blast furnace for combustion, thereby saving energy consumption, having low fuel consumption per ton of pellets, high fuel utilization rate, low operating energy consumption, low pollution emissions, and good energy-saving and emission reduction effects.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A cold pressed pellet drying device, comprising a mesh belt machine, a hot air drying hood, a drying flue gas circulation system, a finished product belt machine, a bellows, a double-layer ash discharge valve, a bulk material belt machine, a drying section I external exhaust flue gas pipeline, a wet desulfurization device, an external exhaust flue gas induced draft fan, a muffler and a chimney, wherein the mesh belt machine is arranged in the hot air drying hood, a bellows is arranged below the hot air drying hood, a double-layer ash discharge valve is arranged below the bellows, a bulk material belt machine is arranged below the double-layer ash discharge valve, the hot air drying hood is divided into a drying section I and a drying section II, the drying section I and the drying section II are connected to the drying flue gas circulation system, a drying section I external exhaust flue gas pipeline is arranged in the exhaust area at the bottom of the drying section I, the drying section I external exhaust flue gas pipeline is connected to the wet desulfurization device, the wet desulfurization device is connected to the wet dust collector and then connected to the chimney through the external exhaust flue gas induced draft fan through the muffler;

[0007] The drying flue gas circulation system comprises a hot blast furnace, a denitration device, a secondary air induced draft fan, a drying II section bellows induced draft fan, a drying II section high temperature bellows hot air duct, a secondary air hot air duct, a drying I section furnace top hot air main pipe, a drying I section furnace top hot air branch pipe, a drying II section furnace top hot air main pipe, and a drying II section furnace top hot air branch pipe. The hot blast furnace is connected to the drying II section furnace top hot air main pipe through the denitration device, and the drying II section furnace top hot air main pipe is connected to a plurality of parallel drying II section furnace top hot air branch pipes and then introduced into the hot air drying hood. Drying section II, the high temperature area at the bottom of the drying section II is provided with a drying section II high temperature bellows hot air duct, the drying section II high temperature bellows hot air duct is connected to the drying section I furnace top hot air main pipe through the drying section II bellows induced draft fan, the drying section I furnace top hot air main pipe is connected to a number of parallel drying section I furnace top hot air branch pipes and then leads into the drying section I of the hot air drying fume hood, the high temperature area at the bottom of the drying section I and the low temperature area at the bottom of the drying section II are jointly provided with a secondary air hot air duct, and the secondary air hot air duct is connected to the hot air furnace through the secondary air induced draft fan.

[0008] Furthermore, a burner is arranged inside the hot blast furnace, and a combustion-supporting air duct and a fuel duct are arranged outside the burner.

[0009] Furthermore, the combustion-supporting air duct is divided into two routes, and both routes of the combustion-supporting air duct are provided with valves and combustion-supporting fans in sequence.

[0010] Furthermore, the drying method of the cold pressed pellet drying equipment comprises the following contents:

[0011] S1. The raw balls of undried cold-pressed pellets are evenly distributed to the receiving end of the mesh belt conveyor, and enter the hot air drying hood as the mesh belt conveyor moves forward, and pass through the drying section I and the drying section II in sequence. The hot air used for drying in the drying section I and the drying section II comes from the hot air fume circulation system;

[0012] S2. The hot drying air of the drying section I comes from the hot air main pipe on the top of the drying section I, and is delivered to the furnace of the drying section I through the evenly distributed hot air branch pipes on the top of the drying section I. The hot air of the hot air main pipe on the top of the drying section I comes from the high-temperature flue gas in the high-temperature area at the bottom of the drying section II. A high-temperature wind box hot air duct for the drying section II is arranged at the bottom of the drying section II. The high-temperature flue gas generated in the drying section II is delivered to the hot air main pipe on the top of the drying section I through the high-temperature wind box hot air duct for the drying section II and the wind box induced draft fan for the drying section II arranged on the high-temperature wind box hot air duct for the drying section II.

[0013] S3. Drying hot air from the drying section II furnace top hot air main pipe is sent to the drying section II furnace through the evenly distributed drying section II furnace top hot air branch pipe. The hot air from the drying section II furnace top hot air main pipe comes from the hot air supplied by the hot blast furnace.

[0014] S4. The hot blast furnace introduces the wind box flue gas in the high temperature area at the bottom of drying section I and the wind box flue gas in the low temperature area at the bottom of drying section II as the secondary air of the hot blast furnace through the secondary air induced draft fan. The amount of hot air introduced into the hot blast furnace by drying section I and drying section II is obtained by hot air balance calculation, that is, the amount of flue gas generated by combustion plus the amount of water vapor generated is equal to the amount of flue gas discharged, so as to achieve dynamic balance;

[0015] S5. The combustion process of the hot blast furnace fuel will produce nitrogen oxides. The nitrogen oxides are removed to a concentration below the environmental protection requirement by a denitrification device installed on the hot blast duct at the hot blast furnace outlet, and then hot air is supplied to the hot blast main pipe on the top of the drying section II furnace;

[0016] S6. The flue gas in the low-temperature wind box in the exhaust area at the bottom of the drying section I is discharged through the exhaust gas duct of the drying section I and the wet desulfurization device, wet dust collector, exhaust gas induced draft fan, silencer and chimney arranged on the exhaust gas duct of the drying section I;

[0017] S7. The dried cold pressed balls are sent to the finished product conveyor for transportation out of the factory. The dust and bulk materials generated during the drying process are discharged through the double-layer dust discharge valve to the bulk material conveyor for transportation out of the factory.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] (1) The drying equipment has a simple structure, low manufacturing cost, low investment, easy use, low professional requirements, small maintenance, small workload for operators, high maintenance efficiency, and good green ball drying effect;

[0020] (2) The secondary air formed by the high temperature area at the bottom of drying section I and the low temperature area at drying section II in the hot air drying hood is introduced into the hot air furnace. The hot air furnace heats quickly, has a large amount of hot air, saves fuel, has low fuel consumption per ton of ball, has high fuel utilization rate, and saves resources;

[0021] (3) The high-temperature flue gas from the drying section II in the hot air drying hood is introduced into the drying section I to preheat and dry the cold-pressed pellets. The cold-pressed pellets have high drying efficiency and good drying effect. The high-temperature flue gas is reused, the operating cost is low, the operation is convenient, the use safety is high, the service life is long, the operating energy consumption is small, the pollution emission is low, and the energy saving and emission reduction effect is good. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 The present invention is a schematic diagram of the working process of a cold-pressed pellet drying device.

[0023] In the figure: 1. mesh belt conveyor; 2. drying section I; 3. drying section II; 4. hot air main pipe on the top of drying section I; 4-1. hot air branch pipe on the top of drying section I; 5. hot air main pipe on the top of drying section II; 5-1. hot air branch pipe on the top of drying section II; 6. hot air furnace; 7. finished product belt conveyor; 8. bellows; 9. double-layer ash discharge valve; 10. bulk material belt conveyor; 11. burner; 12. combustion-supporting fan; 13. valve; 14. combustion-supporting air duct; 14-1 fuel pipeline; 15. secondary air hot air duct; 16. secondary air induced draft fan; 17. high-temperature bellows hot air duct of drying section II; 18. bellows induced draft fan of drying section II; 19 de-pinning device; 20. external exhaust gas duct of drying section I; 21. wet desulfurization device; 22. wet dust collector; 23. external exhaust gas induced draft fan; 24. silencer; 25. chimney. DETAILED DESCRIPTION

[0024] The specific implementation of the present invention will be further described below in conjunction with the accompanying drawings:

[0025] like Figure 1 As shown, the working principle of a cold-pressed pellet drying equipment is as follows: the cold-pressed pellets enter the hot air drying hood through the mesh belt conveyor 1, and the hot air drying hood is divided into a drying section I 2 and a drying section II 3. After passing through the drying flue gas circulation system, the high-temperature flue gas after drying in the drying section II 3 is introduced into the drying section I 2 to preheat the cold-pressed pellets in the drying section I 2. The flue gas in the high-temperature area at the bottom of the drying section I 2 and the low-temperature area at the bottom of the drying section II 3 enter the hot air furnace 6. After being heated by the hot air furnace 6, dry hot air is provided to the drying section II 3, and the dried cold-pressed pellets are delivered to the finished product. The dust and bulk materials generated during the drying process are discharged through the double-layer ash discharge valve 9 to the bulk material belt conveyor 10 for transportation out of the factory. The flue gas in the smoke exhaust area at the bottom of the drying section I 2 is discharged through the drying section I external smoke exhaust duct 20 and the wet desulfurization device 21, wet dust collector 22, external smoke exhaust fan 23, silencer 24 and chimney 25 arranged on the drying section I external smoke exhaust duct 20, thereby saving energy consumption, having low fuel consumption per ton, high fuel utilization rate, low operating energy consumption, low pollution emissions and good energy-saving and emission reduction effects.

[0026] like Figure 1As shown, a cold-pressed pellet drying device comprises a mesh belt conveyor 1, a hot air drying hood, a drying flue gas circulation system, a finished product belt conveyor 7, a bellows 8, a double-layer ash discharge valve 9, a bulk material belt conveyor 10, a drying section I external exhaust gas duct 20, a wet desulfurization device 21, an external exhaust gas induced draft fan 23, a muffler 24 and a chimney 25. The mesh belt conveyor 1 is arranged in the hot air drying hood, a bellows 8 is arranged below the hot air drying hood, a double-layer ash discharge valve 9 is arranged below the bellows 8, and a double-layer ash discharge valve 9 is arranged below the bellows 8. 9 is provided with a bulk material belt conveyor 10, the hot air drying hood is divided into a drying section I 2 and a drying section II 3, the drying section I 2 and the drying section II 3 are connected to a drying flue gas circulation system, the exhaust area at the bottom of the drying section I 2 is provided with a drying section I external exhaust gas duct 20, the drying section I external exhaust gas duct 20 is connected to a wet flue gas desulfurization device 21, the wet flue gas desulfurization device 21 is connected to a wet dust collector 22, and then connected to a chimney 25 through an external exhaust flue gas induced draft fan 23 and a muffler 24;

[0027] The drying flue gas circulation system comprises a hot blast furnace 6, a denitration device 19, a secondary air induced draft fan 16, a drying II section wind box induced draft fan 18, a drying II section high temperature wind box hot air duct 17, a secondary air hot air duct 15, a drying I section furnace top hot air main pipe 4, a drying I section furnace top hot air branch pipe 4-1, a drying II section furnace top hot air main pipe 5, and a drying II section furnace top hot air branch pipe 5-1. The hot blast furnace 6 is connected to the drying II section furnace top hot air main pipe 5 through the denitration device 19, and the drying II section furnace top hot air main pipe 5 is connected to a plurality of parallel drying II section furnace top hot air branch pipes 5-1 and then introduces hot air drying flue gas. The drying section II 3 of the hood, the drying section II 3 bottom high temperature area is provided with a drying section II high temperature bellows hot air duct 17, the drying section II high temperature bellows hot air duct 17 is connected to the drying section I furnace top hot air main pipe 4 through the drying section II bellows induced draft fan 18, the drying section I furnace top hot air main pipe 4 is connected to a plurality of parallel drying section I furnace top hot air branch pipes 4-1 and then introduced into the drying section I 2 of the hot air drying fume hood, the drying section I 2 bottom high temperature area and the drying section II 3 bottom low temperature area are jointly provided with a secondary air hot air duct 15, and the secondary air hot air duct 15 is connected to the hot air furnace 6 through the secondary air induced draft fan 16.

[0028] Furthermore, a burner 11 is arranged in the hot blast furnace 6, and a combustion-supporting air duct 14 and a fuel pipeline 14-1 are arranged outside the burner 11. The high-temperature flue gas of the drying flue gas circulation system comes from the hot blast furnace 6 burning the fuel, and the fuel comes from the fuel pipeline 14-1. The hot blast furnace 6 is equipped with a burner 11 and two combustion-supporting fans 12, one for working and one for standby, and the operation is switched by a valve 13 on the combustion-supporting air duct 14.

[0029] Furthermore, the combustion-supporting air duct 14 is divided into two routes, and the two combustion-supporting air ducts 14 are each provided with a valve 13 and a combustion-supporting fan 12 in sequence.

[0030] Furthermore, the drying method of the cold pressed pellet drying equipment comprises the following contents:

[0031] S1. The raw balls of undried cold-pressed pellets are evenly distributed to the receiving end of the mesh belt conveyor 1, and enter the hot air drying hood as the mesh belt conveyor 1 moves forward, and pass through the drying section I 2 and the drying section II 3 in sequence. The hot air used for drying the drying sections I 2 and II 3 comes from the hot air fume circulation system;

[0032] S2. The hot drying air of the drying section 1 2 comes from the hot air main pipe 4 on the top of the drying section 1, and is delivered to the furnace of the drying section 1 2 through the evenly distributed hot air branch pipes 4-1 on the top of the drying section 1. The hot air of the hot air main pipe 4 on the top of the drying section 1 comes from the high-temperature flue gas in the high-temperature area at the bottom of the drying section 2 3. A hot air duct 17 of a hot air box ...

[0033] S3. Drying II section 3 drying hot air comes from the drying II section furnace top hot air main 5, and is sent to the drying II section 3 furnace through the uniformly distributed drying II section furnace top hot air branch 5-1, and the hot air of the drying II section furnace top hot air main 5 comes from the hot air supplied by the hot blast furnace 6;

[0034] S4. The hot blast furnace 6 introduces the wind box flue gas from the high temperature area at the bottom of the drying section I 2 and the low temperature area at the bottom of the drying section II 3 as the secondary air of the hot blast furnace 6 through the secondary air induced draft fan 16, saving fuel. The amount of hot air introduced into the drying section I and the drying section II by the hot blast furnace 6 is obtained through hot air balance calculation, that is, the amount of flue gas generated by combustion plus the amount of water vapor generated is equal to the amount of flue gas discharged, achieving dynamic balance;

[0035] S5. The combustion process of the fuel in the hot blast furnace 6 will produce nitrogen oxides, which are removed by the denitrification device 19 provided on the hot blast duct at the outlet of the hot blast furnace 6 to a concentration below the environmental protection requirement, and then hot air is supplied to the hot blast main pipe 5 at the top of the drying section II;

[0036] S6. The flue gas in the low-temperature wind box in the exhaust area at the bottom of the drying section 1 2 is discharged through the exhaust gas duct 20 of the drying section 1 and the wet desulfurization device 21, the wet dust collector 22, the exhaust gas induced draft fan 23, the muffler 24 and the chimney 25 arranged on the exhaust gas duct 20 of the drying section 1;

[0037] S7. The dried cold pressed balls are sent to the finished product belt conveyor 7 for transportation out of the factory. The dust and bulk materials generated during the drying process are discharged through the double-layer dust discharge valve 9 to the bulk material belt conveyor 10 for transportation out of the factory.

[0038] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solutions and concepts of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A cold press pellet drying equipment, comprising a mesh belt conveyor, a hot air drying hood, a drying flue gas circulation system, a finished product belt conveyor, a bellows, a double-layer ash discharge valve, a bulk material belt conveyor, a drying I stage external exhaust gas pipeline, a wet desulfurization device, an external exhaust gas induced draft fan, a muffler and a chimney, characterized in that: The mesh belt machine is covered in a hot air drying hood, a bellows is arranged below the hot air drying hood, a double-layer ash discharge valve is arranged below the bellows, a bulk material belt machine is arranged below the double-layer ash discharge valve, the hot air drying hood is divided into a drying section I and a drying section II, the drying section I and the drying section II are connected to a drying flue gas circulation system, a drying section I external exhaust gas duct is arranged in the exhaust area at the bottom of the drying section I, the drying section I external exhaust gas duct is connected to a wet flue gas desulfurization device, the wet flue gas desulfurization device is connected to a wet dust collector, and then connected to a chimney through a muffler via an external exhaust gas induced draft fan; The drying flue gas circulation system comprises a hot blast furnace, a denitration device, a secondary air induced draft fan, a drying II section bellows induced draft fan, a drying II section high temperature bellows hot air duct, a secondary air hot air duct, a drying I section furnace top hot air main pipe, a drying I section furnace top hot air branch pipe, a drying II section furnace top hot air main pipe, and a drying II section furnace top hot air branch pipe. The hot blast furnace is connected to the drying II section furnace top hot air main pipe through the denitration device, and the drying II section furnace top hot air main pipe is connected to a plurality of parallel drying II section furnace top hot air branch pipes and then introduced into the hot air drying hood. Drying section II, the high temperature area at the bottom of the drying section II is provided with a drying section II high temperature bellows hot air duct, the drying section II high temperature bellows hot air duct is connected to the drying section I furnace top hot air main pipe through the drying section II bellows induced draft fan, the drying section I furnace top hot air main pipe is connected to a number of parallel drying section I furnace top hot air branch pipes and then leads into the drying section I of the hot air drying fume hood, the high temperature area at the bottom of the drying section I and the low temperature area at the bottom of the drying section II are jointly provided with a secondary air hot air duct, and the secondary air hot air duct is connected to the hot air furnace through the secondary air induced draft fan.

2. The cold pressed pellet drying equipment according to claim 1, characterized in that: A burner is arranged inside the hot blast furnace, and a combustion-supporting air pipeline and a fuel pipeline are arranged outside the burner.

3. The cold pressed pellet drying equipment according to claim 2, characterized in that: The combustion-supporting air duct is divided into two routes, and valves and combustion-supporting fans are arranged in sequence on both routes of the combustion-supporting air duct.

4. The drying method of the cold pressed pellet drying equipment according to claim 1, characterized in that: The drying method of the cold pressed pellet drying equipment comprises the following contents: S1. The raw balls of undried cold-pressed pellets are evenly distributed to the receiving end of the mesh belt conveyor, and enter the hot air drying hood as the mesh belt conveyor moves forward, and pass through drying section I and drying section II in sequence; S2. The hot drying air of the drying section I comes from the hot air main pipe on the top of the drying section I, and is delivered to the furnace of the drying section I through the evenly distributed hot air branch pipes on the top of the drying section I. The hot air of the hot air main pipe on the top of the drying section I comes from the high-temperature flue gas in the high-temperature area at the bottom of the drying section II. A high-temperature wind box hot air duct for the drying section II is arranged at the bottom of the drying section II. The high-temperature flue gas generated in the drying section II is delivered to the hot air main pipe on the top of the drying section I through the high-temperature wind box hot air duct for the drying section II and the wind box induced draft fan for the drying section II arranged on the high-temperature wind box hot air duct for the drying section II. S3. Drying hot air from the drying section II furnace top hot air main pipe is sent to the drying section II furnace through the evenly distributed drying section II furnace top hot air branch pipe. The hot air from the drying section II furnace top hot air main pipe comes from the hot air supplied by the hot blast furnace. S4. The hot blast furnace introduces the wind box flue gas in the high temperature area at the bottom of drying section I and the wind box flue gas in the low temperature area at the bottom of drying section II as the secondary air of the hot blast furnace through the secondary air induced draft fan. The amount of hot air introduced into the hot blast furnace by drying section I and drying section II is obtained by hot air balance calculation, that is, the amount of flue gas generated by combustion plus the amount of water vapor generated is equal to the amount of flue gas discharged, so as to achieve dynamic balance; S5. The combustion process of the hot blast furnace fuel will produce nitrogen oxides. The nitrogen oxides are removed to a concentration below the environmental protection requirement by a denitrification device installed on the hot blast duct at the hot blast furnace outlet, and then hot air is supplied to the hot blast main pipe on the top of the drying section II furnace; S6. The flue gas in the low-temperature wind box in the exhaust area at the bottom of the drying section I is discharged through the exhaust gas duct of the drying section I and the wet desulfurization device, wet dust collector, exhaust gas induced draft fan, silencer and chimney arranged on the exhaust gas duct of the drying section I; S7. The dried cold pressed balls are sent to the finished product conveyor for transportation out of the factory. The dust and bulk materials generated during the drying process are discharged through the double-layer dust discharge valve to the bulk material conveyor for transportation out of the factory.

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