Methanol-to-hydrogen mixed natural gas calcining device for potassium fertilizer production rotary kiln

Abstract

The invention discloses a methanol-to-hydrogen and natural gas mixed calcining device for a potassium fertilizer production rotary kiln, which comprises a suspension preheater module, a rotary kiln cylinder main body, a gas-gas mixed combustor, a single-cylinder water-gas double-cooling cooler and a methanol-to-hydrogen device, and is characterized in that the gas-gas mixed combustor is arranged on one side of the end part of a rotary kiln head of the rotary kiln cylinder main body; through combined use of the methanol hydrogen production device and natural gas, dependence on traditional fossil fuel is reduced, generation of fly ash is effectively avoided, emission of greenhouse gases such as carbon dioxide is reduced, the environmental protection requirement is improved, hot water recovered by the single-barrel water-gas double-cooling cooler is used as one of raw materials in the methanol hydrogen production process, and the production cost is reduced. The energy utilization efficiency is improved; the suspension preheater module adopts a multi-stage circulation design, waste heat in high-temperature waste gas exhausted by the rotary kiln is fully utilized, raw materials entering the system are efficiently preheated, and fuel needed by calcination is reduced.

Description

Technical Field

[0001] The present application is a methanol-to-hydrogen supply rotary kiln calcination system in the potash fertilizer production process, which relates to the technical field of rotary kilns in potash fertilizer production, and specifically is a methanol-to-hydrogen mixed natural gas calcination device used in a potash fertilizer production rotary kiln. Background Art

[0002] In recent years, my country's manufacturing industry has developed rapidly, and the consumption of various resources has been accelerating, and energy has also been greatly affected. Fossil energy, as a traditional energy storage and energy supply carrier, has been continuously mined and consumed, and the emission of harmful substances such as nitrogen oxides and sulfur oxides has increased year by year. In order to achieve sustainable development, my country's environmental protection industry needs to have relatively high requirements, which makes everyone focus more on the field of new energy, in order to achieve the purpose of energy conservation and emission reduction as much as possible while meeting production needs.

[0003] The production of soluble potassium fertilizer uses insoluble potassium feldspar as raw material to produce soluble potassium. It is a high-energy consumption manufacturing industry. Especially in the process of firing clinker, in order to destroy the material structure of potassium feldspar and achieve partial activation, high-temperature calcination is required, which consumes a lot of heat energy. Kiln is the main heating facility, and its selection is a crucial link in the entire production process design. The quality of its performance will directly affect the output, quality and economic benefits of the product.

[0004] Rotary kilns are widely used in the cement industry and belong to the category of building materials equipment. According to the different materials processed, they can be roughly divided into cement kilns (used for calcining cement clinker), lime kilns (used for roasting active lime and light-burned dolomite) and metallurgical chemical kilns (mainly used for various roasting in the metallurgical industry). According to the different energy supply fuels, they can be divided into gas-fired rotary kilns (using coal gas or natural gas as fuel), coal-fired rotary kilns (using coal powder as fuel), and mixed fuel rotary kilns (mostly used for coal powder and coal gas mixed fuel combustion).

[0005] The rotary kiln has the advantages of high production capacity, strong adaptability of calcined raw materials, uniform and stable calcination quality, etc. However, due to the large fly ash loss and heat loss of the current rotary kiln equipment, the amount of raw materials and fuel consumed for processing and calcining unit products is large, and the dust removal problem is difficult to solve, the fly ash loss is large, and it is difficult to meet environmental protection requirements. Summary of the invention

[0006] The technical problem to be solved by the present application is to overcome the existing defects and provide a methanol-to-hydrogen mixed natural gas calcination device for potash fertilizer production rotary kiln, which can effectively solve the problems in the background technology.

[0007] To achieve the above-mentioned purpose, the present application provides the following technical solutions: a methanol-to-hydrogen mixed natural gas calcining device for potash fertilizer production rotary kiln, comprising a suspension preheater module, a rotary kiln barrel body, a gas-gas mixing burner, a single-barrel water-gas dual-cooling cooler and a methanol hydrogen production device, a gas-gas mixing burner is arranged on one side of the rotary kiln head end of the rotary kiln barrel body, a single-barrel water-gas dual-cooling cooler is connected to the lower end of the rotary kiln head end of the rotary kiln barrel body, a gas output end of the heat exchange system of the single-barrel water-gas dual-cooling cooler is connected to the gas input end of the methanol hydrogen production equipment, a gas supply pipeline is connected to the rear end of the gas-gas mixing burner, and the gas supply pipeline is connected to the output port of the methanol hydrogen production equipment; A suspension preheater module is arranged above the kiln tail of the rotary kiln body, and a material discharge pipe and an ascending mixed hot air flow pipe are arranged between the kiln tail of the rotary kiln body and the lower opening of the suspension preheater module.

[0008] As a preferred technical solution of the present application, the single-cylinder water-gas dual-cooling cooler cylinder is composed of two layers, an inner layer and an outer layer, and the channel between the inner and outer layers is a cooling heat exchange channel, and the output end of the channel is connected to the input end of the methanol hydrogen production equipment.

[0009] As a preferred technical solution of the present application, a spiral pipe is formed in the interlayer of the cylinder of the single-cylinder water-gas dual-cooling cooler for circulating cooling water.

[0010] As a preferred technical solution of the present application, the combustion chamber of the gas-gas mixing burner is equipped with multiple layers of combustion nozzles, and multiple fire outlets are arranged at the end thereof.

[0011] As a preferred technical solution of the present application, a gas mixing valve is provided on the gas supply pipeline, and the gas mixing valve is connected to the output port of the methanol hydrogen production equipment.

[0012] As a preferred technical solution of the present application, the ascending mixed hot air flow duct is arranged around the suspension preheater module, and there are multiple air inlets evenly arranged around the suspension preheater module.

[0013] As a preferred technical solution of the present application, the suspension preheater module is composed of a plurality of groups of suspension preheaters; the suspension preheater module is composed of a secondary downstream suspension preheater and a downstream suspension preheater, and a material channel and an airflow channel are provided between the two.

[0014] As a preferred technical solution of the present application, the airflow channel is designed in a surrounding manner and is arranged on the secondary downstream suspension preheater and the downstream suspension preheater.

[0015] Compared with the prior art: the present application reduces dependence on traditional fossil fuels, effectively avoids the generation of fly ash, reduces emissions of greenhouse gases such as carbon dioxide, and improves environmental protection requirements by combining the use of a methanol hydrogen production device with natural gas in a rotary kiln dedicated to potash fertilizer production. The hot water recovered by a single-cylinder water-gas double-cooling cooler is used as one of the raw materials in the methanol hydrogen production process, thereby improving energy utilization efficiency; the suspended preheater module adopts a multi-stage circulation design, fully utilizing the waste heat in the high-temperature exhaust gas discharged from the rotary kiln, and efficiently preheats the raw materials entering the system, reducing the fuel required for calcination. At the same time, the design of the surrounding rising mixed hot air flow pipeline avoids local overheating, increases the contact area between the hot air flow and the raw materials, improves the preheating efficiency, and further reduces energy waste; the recovered hot water and waste heat in the exhaust gas are utilized to reduce additional energy consumption and reduce production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of the structure of this application; Figure 2 Schematic diagram of the suspension preheater module structure.

[0017] In the figure: 1 rotary kiln drum body, 2 gas-gas mixing burner, 3 single-drum water-gas dual-cooling cooler, 4 methanol hydrogen production device, 5 suspension preheater module, 6 gas supply pipeline, 7 rising mixed hot air flow pipeline. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application (for the convenience of description and understanding, the following is Figure 2 All other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0019] See also Figure 1-2 The present application provides a technical solution: a methanol-to-hydrogen mixed natural gas calcining device for potash fertilizer production rotary kiln, comprising a suspension preheater module 5, a rotary kiln barrel body 1, a gas-gas mixing burner 2, a single-tube water-gas dual-cooling cooler 3 and a methanol hydrogen production device 4, wherein a gas-gas mixing burner 2 is arranged on one side of the rotary kiln head end of the rotary kiln barrel body 1, a single-tube water-gas dual-cooling cooler 3 is connected to the lower end of the rotary kiln head end of the rotary kiln barrel body 1, a gas output end of the heat exchange system of the single-tube water-gas dual-cooling cooler 3 is connected to the gas input end of the methanol hydrogen production equipment 4, a gas supply pipeline 6 is connected to the rear end of the gas-gas mixing burner 2, and the gas supply pipeline 6 is connected to the output port of the methanol hydrogen production equipment 4; A suspension preheater module 5 is arranged above the kiln tail of the rotary kiln body 1 , and a material discharge pipe and an ascending mixed hot air flow pipe 7 are arranged between the kiln tail of the rotary kiln body and the lower opening of the suspension preheater module 5 .

[0020] The rotary kiln body 1 is the core part of potash fertilizer production, responsible for calcining raw materials such as potassium feldspar at high temperature to produce potash fertilizer. Under the action of the gas-gas mixing burner 2, the preheated raw materials will be fully burned in the rotary kiln body 1, and undergo a series of physical and chemical changes, and finally converted into potash fertilizer products.

[0021] The gas-gas mixing burner 2 is connected to the gas supply pipeline 6 to receive the mixture of hydrogen and natural gas produced by the methanol hydrogen production device 4, and ignites it after sufficient mixing, providing the necessary high-temperature environment for the calcination process in the rotary kiln tube body 1, ensuring a stable heat source supply, and effectively reducing fuel costs while reducing harmful gas emissions.

[0022] The methanol hydrogen production device 4 is responsible for decomposing methanol into hydrogen and carbon dioxide. The generated hydrogen is transported to the gas-gas mixing burner 2 through the gas supply pipeline 6, and is mixed with natural gas to heat the rotary kiln drum body 1. The hot water recovered from the single-drum water-gas dual-cooling cooler 3 is also used as one of the raw materials in the methanol hydrogen production process, which helps to increase the hydrogen production and save energy.

[0023] Furthermore, the cylinder of the single-cylinder water-gas dual-cooling cooler 3 is composed of two layers, an inner layer and an outer layer, and the channel between the inner layer and the outer layer is a cooling heat exchange channel, and the output end of the channel is connected to the input end of the methanol hydrogen production equipment 4.

[0024] The cooling water between the layers is transported through the high-temperature material channel, which is located in the cylinder of the single-cylinder water-gas dual-cooling cooler 3. The cooling water circulates between the cylinder layers. The cooling water absorbs heat and is converted into water vapor, which is input into the methanol hydrogen production equipment 4 and participates in the methanol hydrogen production process as a raw material.

[0025] The single-drum water-gas dual-cooling cooler 3 can not only cool the discharged materials efficiently, but also recycle the hot water generated during the cooling process, thereby improving resource utilization.

[0026] Furthermore, the inner layer of the cylinder of the single-cylinder water-gas dual-cooling cooler 3 is provided with a spiral pipe for circulating cooling water.

[0027] The spiral structure increases the contact area and flow path of the fluid, promotes heat exchange between cooling water and hot gas, and improves heat exchange efficiency; it can also cause the fluid to generate vortices during the flow process, enhance the mixing degree of the fluid, and help to uniformly heat or cool; and the spiral design occupies less space than a straight channel, and can achieve a higher heat exchange effect in a limited installation space.

[0028] Furthermore, the combustion chamber of the gas-gas mixing burner 2 is equipped with multiple layers of combustion nozzles, and multiple fire outlets are arranged at the end thereof.

[0029] The multi-layer combustion nozzle can spray the mixed fuel into the combustion chamber more evenly, ensuring that the fuel and combustion air are fully mixed, thereby improving the completeness and efficiency of the combustion; by setting multiple fire outlets, the flame can be evenly distributed in the combustion chamber, reducing the risk of local overheating or extinction, and improving the stability of the combustion process.

[0030] Furthermore, a gas mixing valve is provided on the gas supply pipeline 6 , and the gas mixing valve is connected to the output port of the methanol hydrogen production equipment 4 .

[0031] The gas supply pipeline 6 safely and effectively transports the hydrogen produced by the methanol hydrogen production device 4 to the gas-gas mixing burner 2. By controlling the opening of the gas mixing valve on the pipeline, the flow rates of hydrogen and natural gas are accurately adjusted to ensure that the gas-gas mixing burner 2 obtains the best combustion conditions, thereby improving the combustion efficiency and thermal energy utilization efficiency.

[0032] Furthermore, the ascending mixed hot air flow duct 7 is arranged around the suspension preheater module 5, and there are multiple air inlets evenly arranged around the suspension preheater module 5.

[0033] The rising mixed hot air flow pipeline 7 guides the high-temperature exhaust gas discharged from the rotary kiln drum body 1 to the suspension preheater module 5, transfers the heat in the exhaust gas to the raw materials of the system through heat exchange, heats the raw materials, and realizes efficient use of thermal energy.

[0034] The ascending mixed hot air flow duct 7 is arranged around the suspension preheater module 5 to ensure that the hot air flow is evenly distributed inside the entire suspension preheater module 5, avoiding the problem of local overheating or insufficient preheating.

[0035] Through the design of multiple air outlets, the contact area between the hot air flow and the raw materials can be maximized, the preheating efficiency can be improved, the preheating time can be shortened, and thus the production capacity of the entire production system can be increased.

[0036] Furthermore, the suspension preheater module 5 is composed of a plurality of suspension preheater groups; the suspension preheater module 5 is composed of a secondary downstream suspension preheater and a downstream suspension preheater, and a material channel and an airflow channel are provided between the two.

[0037] The waste heat of hot air is fully utilized through multi-stage circulation between the lower outlet of the secondary downstream suspension preheater and the downstream suspension preheater.

[0038] The lower port of the secondary downstream suspension preheater is connected to the material channel on one side of the downstream suspension preheater, and the material is transported through this pipeline. The high-temperature exhaust gas discharged from the rotary kiln is used to preheat the raw materials entering the system through the air flow channel, thereby improving energy utilization efficiency and reducing energy consumption. Through the multi-stage circulation design, the waste heat in the hot air can be maximized to improve the thermal efficiency of the entire system.

[0039] Furthermore, the airflow channel is designed in a surrounding manner and is arranged on the secondary downstream suspension preheater and the downstream suspension preheater.

[0040] When in use: the potassium feldspar ground to a certain fineness is fed into the suspension preheater module 5 through the feeding port, and after primary preheating and drying, it enters the suspension preheaters of each level in sequence for preheating treatment before calcination, and after the preheating before calcination reaches a certain temperature, it is mixed with the reaction auxiliary materials. The mixed powder is discharged from the last suspension preheater above the rotary kiln to the rotary kiln barrel body 1 for high-temperature calcination reaction to generate citric acid-soluble potassium fertilizer clinker, and the potassium fertilizer clinker is discharged into the single-cylinder water-gas double-cooling cooler 3 through the kiln head of the rotary kiln barrel body 1, and passes through the high-temperature material channel in the single-cylinder water-gas double-cooling cooler 3, and after cooling, it is sent to the clinker warehouse for storage or directly transferred to the granulation system for granulation.

[0041] Airflow direction: during production, the high-temperature resistant single-cylinder water-gas dual-cooling cooler 3 is started, and the cooling water passes through the interlayer channel of the single-cylinder water-gas dual-cooling cooler 3 to cool the calcined materials. The cooling water that absorbs heat enters the methanol hydrogen production equipment 4 through the pipeline and participates in the methanol hydrogen production process as a raw material. The hydrogen produced after decomposition enters the gas supply pipeline 6 together with the natural gas. The inner cylinder of the single-cylinder water-gas dual-cooling cooler 3 collects the cooling air to generate airflow through the pipeline. The cooling airflow enters the rotary kiln barrel body 1 and intersperses with the high-temperature clinker in the reverse direction for heat exchange. After the heat exchange, the hot air is used as combustion-supporting air and merges in the gas supply pipeline 6 through the gas mixing valve. The mixed gas is burned in the gas-gas mixing burner 2. The hot flue gas passes through the kiln head of the rotary kiln barrel body 1 to the kiln tail and then enters the various levels of suspension preheaters in turn as a heat source for preheating potassium feldspar. After the multi-stage preheater, the airflow pressure is reduced, and the dust is separated from the flue gas and returns to the lower pipeline. The flue gas is finally collected in the upper tail gas treatment system and discharged after the tail gas treatment.

[0042] Although the embodiments of the present application have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present application, and that the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A methanol-to-hydrogen mixed natural gas calcination device for potash fertilizer production rotary kiln, characterized in that: The invention comprises a suspension preheater module (5), a rotary kiln barrel body (1), a gas-gas mixing burner (2), a single-barrel water-gas dual-cooling cooler (3) and a methanol hydrogen production device (4), wherein a gas-gas mixing burner (2) is arranged on one side of the rotary kiln head end of the rotary kiln barrel body (1), a single-barrel water-gas dual-cooling cooler (3) is connected to the lower end of the rotary kiln head end of the rotary kiln barrel body (1), a gas output end of the heat exchange system of the single-barrel water-gas dual-cooling cooler (3) is connected to the gas input end of the methanol hydrogen production device (4), a gas supply pipeline (6) is connected to the rear end of the gas-gas mixing burner (2), and the gas supply pipeline (6) is connected to the output port of the methanol hydrogen production device (4); A suspension preheater module (5) is arranged above the kiln tail of the rotary kiln body, and a material discharge pipe and an ascending mixed hot air flow pipe (7) are arranged between the kiln tail of the rotary kiln body and the lower opening of the suspension preheater module (5).

2. The methanol-to-hydrogen mixed natural gas calcination device for potash fertilizer production rotary kiln according to claim 1, characterized in that: The cylinder of the single-cylinder water-gas dual-cooling cooler (3) is composed of two layers, an inner layer and an outer layer, and the channel between the inner layer and the outer layer is a cooling heat exchange channel, and the output end of the channel is connected to the input end of the methanol hydrogen production equipment (4).

3. The methanol-to-hydrogen mixed natural gas calcination device for potash fertilizer production rotary kiln according to claim 2, characterized in that: The single-cylinder water-gas dual-cooling cooler (3) has a spiral pipe in the interlayer of the cylinder for circulating cooling water.

4. The methanol-to-hydrogen mixed natural gas calcination device for potash fertilizer production rotary kiln according to claim 1, characterized in that: The combustion chamber of the gas-gas mixing burner (2) is equipped with multiple layers of combustion nozzles, and the ends thereof are provided with multiple fire outlets.

5. The methanol-to-hydrogen mixed natural gas calcination device for potash fertilizer production rotary kiln according to claim 1, characterized in that: The gas supply pipeline (6) is provided with a gas mixing valve, and the gas mixing valve is connected to the output port of the methanol hydrogen production equipment (4).

6. The methanol-to-hydrogen mixed natural gas calcination device for potash fertilizer production rotary kiln according to claim 1, characterized in that: The ascending mixed hot air flow duct (7) is arranged around the suspension preheater module (5), and multiple air inlets are evenly arranged around the suspension preheater module (5).

7. The methanol-to-hydrogen mixed natural gas calcination device for potash fertilizer production rotary kiln according to claim 1, characterized in that: The suspension preheater module (5) is composed of a plurality of groups of suspension preheaters; the suspension preheater module (5) is composed of a secondary downstream suspension preheater and a downstream suspension preheater, and a material channel and an airflow channel are provided between the two.

8. The methanol-to-hydrogen mixed natural gas calcination device for potash fertilizer production rotary kiln according to claim 7, characterized in that: The airflow channel is designed in a surrounding manner and is arranged on the secondary downstream suspension preheater and the downstream suspension preheater.

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