CN-122015493-A - Mannheim furnace with preheating structure and potassium sulfate preparation process

CN122015493ACN 122015493 ACN122015493 ACN 122015493ACN-122015493-A

Abstract

The invention discloses a Mannheim furnace with a preheating structure and a potassium sulfate preparation process, which relate to the technical field of kilns, wherein a furnace charge preheating structure and a spiral heating bent pipe are arranged on the Mannheim furnace, the furnace charge preheating structure can absorb heat of flue gas discharged from a smoke exhaust pipe and preheat solid potassium chloride raw materials through the heat, the spiral heating bent pipe can absorb the heat of the flue gas to preheat concentrated sulfuric acid for conveying and feeding, and therefore, the furnace charge preheating structure and the spiral heating bent pipe can absorb heat and cool through double heat absorption, the heat loss during the fume emission can be greatly reduced, meanwhile, the raw material heating efficiency and the reaction efficiency can be improved through preheating the potassium chloride and the concentrated sulfuric acid, and further the preparation efficiency and the preparation effect of the potassium sulfate are improved.

Inventors

LIU DONGQIU
QU ZHI
ZHANG YUHANG

Assignees

广东米高化工有限公司

Dates

Publication Date: 20260512
Application Date: 20260210

Claims (10)

1. The furnace charge preheating structure comprises a feeding part and a waste heat recovery part, wherein the feeding part can be used for conveying and feeding furnace charges, and the waste heat recovery part can recover heat of flue gas discharged from a furnace and heat the furnace charges conveyed in the feeding part through the recovered heat; The feeding part comprises a feeding conveying part, a blanking control part and an auxiliary blanking part, wherein the feeding conveying part can carry out blanking conveying of furnace charges, the blanking control part comprises a furnace charge interception state and a blanking state, the blanking control part can intercept and stop the furnace charges which are blanked and conveyed in the feeding conveying part in the furnace charge interception state so as to enable the furnace charges to be continuously preheated in the feeding conveying part, and the blanking control part can continuously and downwards blanking and conveying the furnace charges which are intercepted and stopped in the feeding conveying part in the blanking state; The auxiliary blanking part enters an auxiliary blanking state when the blanking control part is in a charge interception state, at the moment, the auxiliary blanking part can impact and break up the charge conveyed into the charge conveying part so as to enable the charge to be scattered on the blanking control part, the auxiliary blanking part can also enter a temporary interception state when the blanking control part is in the blanking state, at the moment, the auxiliary blanking part can temporarily intercept the charge conveyed into the charge conveying part, and the temporarily intercepted charge is conveyed to the blanking control part when the blanking control part returns to the charge interception state; The waste heat recovery part comprises a heat exchange part and a heating part, the heat exchange part can absorb heat of flue gas discharged from the furnace, and the heating part can heat the feeding conveying part through the absorbed heat.
2. The furnace burden preheating structure according to claim 1, wherein the feeding and conveying part comprises a feeding pipe, a feeding hopper is fixedly arranged at the top end of the feeding pipe, a blanking hopper is arranged at one side of the bottom end of the feeding pipe, a feeding hole is formed in the blanking hopper, and the blanking control part can convey furnace burden in the feeding pipe into the blanking hopper through the feeding hole; The sealing structure is arranged in the feeding hole and can seal the feeding hole when the blanking control part is in a furnace charge interception state, and the sealing structure can release the sealing of the feeding hole when the blanking control part is in a blanking state.
3. The furnace burden preheating structure according to claim 2, wherein the blanking control part comprises a material plate and a rotary driving part, the material plate is rotatably arranged at the bottom end of the feeding pipe, the blanking end of the material plate extends into the feeding hole of the blanking hopper, the rotary driving part can drive the material plate to be in sealing abutting connection with the bottom end of the feeding pipe, and the rotary driving part can also drive the material plate to rotate downwards towards the blanking square sheet of paper used for painting or calligraphy.
4. The furnace charge preheating structure according to claim 3, wherein the sealing structure comprises a guide rail, the guide rail is fixedly arranged on one side of the feed inlet, a sealing plate capable of sealing the feed inlet in an abutting mode is arranged in the guide rail in a lifting sliding mode, an elastic supporting structure is arranged at the bottom end of the sealing plate in a connecting mode, the top end of the sealing plate is driven by supporting elastic force of the elastic supporting structure to be in abutting connection with the bottom surface of the feed plate, and the sealing plate can be in downward abutting sliding displacement along the guide rail during material plate rotation and blanking to release sealing of the sealing plate on the feed inlet.
5. The furnace burden preheating structure according to claim 2, wherein the auxiliary blanking part comprises an angle adjusting driving part and a plurality of rotating shafts, the rotating shafts are equidistantly distributed and rotatably arranged at the upper end inside the feeding pipe, the rotating shafts are fixedly provided with laths, the angle adjusting driving part can drive the rotating shafts to synchronously rotate, so that the rotating shafts drive the laths to reciprocally adjust between a horizontal state and a non-horizontal state, when the laths are in the horizontal state, adjacent laths are spliced in sequence to form a horizontal interception structure, the furnace burden conveyed into the feeding pipe can be intercepted, when the laths are in the non-horizontal state, a blanking channel for the furnace burden to pass through is reserved between the adjacent laths, and the laths can impact and break up the furnace burden conveyed by blanking through the upper side.
6. The furnace charge preheating structure according to claim 3, wherein the rotary driving part comprises a hydraulic telescopic shaft, a rotary support and a supporting shaft, the rotary support is rotatably arranged on one side of the material plate through the supporting shaft, one end of the rotary support is rotatably connected with the material plate, the other end of the rotary support is connected with a push-pull rod, the hydraulic telescopic shaft is rotatably arranged on one side of the push-pull rod, and the telescopic end of the hydraulic telescopic shaft is rotatably connected with the push-pull rod.
7. The furnace charge preheating structure according to claim 2, wherein the heat exchange part comprises a flue gas heat exchanger, a heat exchange flow channel is arranged in the flue gas heat exchanger, a cold source input pipe and a heat source output pipe which are respectively communicated with two ends of the heat exchange flow channel are fixedly arranged on the outer side of the flue gas heat exchanger, the cold source input pipe can convey a heat exchange medium into the heat exchange flow channel in the flue gas heat exchanger, and the heat exchange medium can absorb flue gas heat to rise when conveyed in the heat exchange flow channel and then be output outwards from the heat source output pipe.
8. The furnace burden preheating structure according to claim 7, wherein the heating part comprises a heat preservation shell, the heat preservation shell is fixedly arranged on the outer ring of the feeding pipe so as to form a heating heat preservation chamber around the outer ring of the feeding pipe, a liquid inlet and a liquid outlet of the heating heat preservation chamber are respectively communicated with the heat source output pipe and the cold source input pipe through a guide pipe, and a circulating pump is arranged on the guide pipe.
9. The Mannheim furnace with the preheating structure comprises the furnace burden preheating structure according to any one of claims 1-8, and is characterized by further comprising a furnace body, wherein a plurality of burners are arranged on the furnace body, a smoke exhaust pipe is arranged at the top end of the furnace body, a liquid feeding pipe is further connected and arranged at the top end of the furnace body, a spiral heating bent pipe is connected and arranged at the feeding end of the liquid feeding pipe, and the spiral heating bent pipe is sleeved on the outer ring of the smoke exhaust pipe.
10. A process for preparing potassium sulfate using the mannheim furnace with preheating structure as claimed in claim 9, comprising the following steps: Continuously conveying the potassium chloride raw material into a feeding conveying part, blanking and conveying the potassium chloride into a furnace body along the feeding conveying part, and performing impact scattering on the blanking and conveying potassium chloride raw material by an auxiliary conveying part, wherein the potassium chloride raw material is intercepted by a blanking control part and stays in the feeding conveying part; The heat exchange part absorbs the heat of the flue gas discharged by the flue gas discharge pipe, and the feeding conveying part is heated by the heat practically absorbed by the heating part so as to preheat the potassium chloride raw material intercepted and stopped in the feeding conveying part; After the preheating of the potassium chloride raw material is finished, the blanking control part enters a blanking state, the preheated potassium chloride raw material is continuously blanked downwards and conveyed into the furnace body, and the auxiliary blanking part temporarily intercepts the potassium chloride raw material which is subsequently conveyed into the feeding conveying part, so that the non-preheated potassium chloride raw material is prevented from being directly blanked and conveyed into the furnace body; Simultaneously, concentrated sulfuric acid liquid is continuously conveyed into the furnace body through the spiral heating bent pipe and the liquid feeding pipe, so that potassium chloride and concentrated sulfuric acid react in the furnace body at high temperature generated by combustion and heating of the burner to generate potassium sulfate.

Description

Mannheim furnace with preheating structure and potassium sulfate preparation process Technical Field The invention belongs to the technical field of kilns, and particularly relates to a Mannheim furnace with a preheating structure and a preparation process of potassium sulfate. Background In the chemical industry, the industrial production of potassium sulfate mainly adopts the Mannheim method. The process generally takes natural gas, heavy oil or coal gas as fuel in China, and generates high-temperature flue gas by mixing and burning with air, and the high-temperature flue gas is used as an external heat source to heat materials in a Mannheim furnace, so that continuous and stable reaction heat is provided for the endothermic reaction of potassium chloride and concentrated sulfuric acid to generate potassium sulfate, and the reaction is pushed to proceed forward. However, the above fuels generate a large amount of high temperature flue gas during combustion, and the emission temperature is usually up to 400 ℃ or more, which contains considerable heat energy. At present, the flue gas is often discharged directly or after simple cooling treatment after the heating of the furnace body is finished, so that a large amount of waste heat is directly dissipated into the environment, obvious energy waste is caused, and meanwhile, the comprehensive energy consumption and carbon emission of the system are increased. In the existing waste heat recovery technology, it is common practice to convey high temperature flue gas to an independent boiler system, and to recover part of the heat by heating water or generating steam. However, the method has a plurality of inherent limitations that firstly, a boiler room, a pipeline system and matched water treatment facilities are additionally built, the initial investment is large, the occupied area is wide, the requirements on the existing production layout transformation are high, secondly, the operation and maintenance of the boiler system are complex, the operation cost is further increased, thirdly, as a certain safety distance between a Mannheim furnace and a waste heat boiler is usually kept, a flue gas conveying pipeline is long, the heat dissipation loss along the way is serious, the energy consumption of a fan required by long-distance conveying is high, and the practical recovery efficiency is limited and the economical efficiency is poor due to the combination. Therefore, how to realize the efficient, low-cost and integrated recycling of the flue gas waste heat of the Mannheim furnace on the premise of not depending on a complex external boiler system becomes a key technical subject for improving the energy efficiency of the process and reducing the production cost and the carbon footprint. Disclosure of Invention Aiming at the problems in the related art, the invention provides a Mannheim furnace with a preheating structure and a preparation process of potassium sulfate, so as to overcome the technical problems in the prior art. In order to solve the technical problems, the invention is realized by the following technical scheme: the invention relates to a Mannheim furnace with a preheating structure, which comprises a furnace burden preheating structure and a furnace body, wherein a plurality of burners are arranged on the furnace body, a smoke exhaust pipe is arranged at the top end of the furnace body, a liquid feeding pipe is further connected and arranged at the top end of the furnace body, a spiral heating bent pipe is connected and arranged at the feeding end of the liquid feeding pipe, and the spiral heating bent pipe is sleeved on the outer ring of the smoke exhaust pipe; The furnace charge preheating structure comprises a feeding part and a waste heat recovery part, wherein the feeding part can be used for conveying and feeding furnace charges, and the waste heat recovery part can recover heat of flue gas discharged from the smoke exhaust pipe and heat the furnace charges conveyed in the feeding part through the recovered heat; The feeding part comprises a feeding conveying part, a blanking control part and an auxiliary blanking part, wherein the feeding conveying part can carry out blanking conveying of furnace charges, the blanking control part comprises a furnace charge interception state and a blanking state, the blanking control part can intercept and stop the furnace charges which are blanked and conveyed in the feeding conveying part in the furnace charge interception state so as to enable the furnace charges to be continuously preheated in the feeding conveying part, and the blanking control part can continuously and downwards blanking and conveying the furnace charges which are intercepted and stopped in the feeding conveying part in the blanking state; The auxiliary blanking part enters an auxiliary blanking state when the blanking control part is in a charge interception state, at the moment, the auxiliary blanking part can impact and break up t