A calcination system for producing cyanuric acid
By introducing a dual-fuel burner and nitrogen replacement into the calcination system, utilizing hydrogen resources, and combining steam heating and pressure control, the problems of low hydrogen utilization and easy damage to the calcination kiln were solved, resulting in cost reduction and improved system safety.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- INNER MONGOLIA LANTAI SODIUM IND CO LTD
- Filing Date
- 2025-06-24
- Publication Date
- 2026-06-30
AI Technical Summary
The existing technology has a low utilization rate of hydrogen resources, which leads to increased production costs, and the calcining kiln is easily damaged by high-temperature flames, resulting in insufficient system safety.
The system employs a dual-fuel burner that combines hydrogen and natural gas, and ensures system safety through a firewall and nitrogen purging. It utilizes hydrogen as a clean energy source, and combines steam heating and pressure sensor control to achieve the resource utilization of hydrogen and stable system operation.
This reduced natural gas consumption, lowered production costs, prevented damage to the kiln bellows, and ensured the safe and stable operation of the system.
Smart Images
Figure CN224434995U_ABST
Abstract
Description
Technical Field
[0001] This utility model patent relates to a calcination system, specifically a calcination system for producing cyanuric acid. Background Technology
[0002] The industrial production process of cyanuric acid involves first heating urea in a calcining kiln to 200-300°C for pyrolysis and cyclization to obtain crude cyanuric acid. This crude cyanuric acid is then mixed with 15%-20% sulfuric acid (or nitric acid, hydrochloric acid) and cooked. After filtration, washing, and drying, the final product, cyanuric acid, is obtained. Currently, natural gas is used to provide heat to the calcining kiln; however, natural gas must be purchased from a gas company, thus increasing the production cost of cyanuric acid.
[0003] Currently, the company uses an electrolytic method to produce sodium chlorate, which uses sodium chloride solution as raw material and obtains the finished product through steps such as pH adjustment, electrolysis, and purification. Hydrogen is produced as a byproduct, but it is currently being emitted directly, resulting in low utilization and waste of resources. Utility Model Content
[0004] In view of this, the purpose of this utility model is to provide a calcination system for producing cyanuric acid with a simple connection structure, which realizes the utilization of hydrogen resources and ensures the safe and stable operation of the hydrogen system.
[0005] This utility model discloses a calcination system for producing cyanuric acid, comprising a calcination kiln, a dual-fuel burner, a hydrogen delivery pipe, a natural gas delivery pipe, an instrument gas delivery pipe, a blower, and a nitrogen delivery pipe. A hot air channel is provided on the calcination kiln, and the dual-fuel burner is fixedly installed at one end of the hot air channel away from the calcination kiln. The outlet of the hydrogen delivery pipe is connected to the first fuel gas inlet of the dual-fuel burner, the outlet of the natural gas delivery pipe is connected to the second fuel gas inlet of the dual-fuel burner, the outlet of the instrument gas delivery pipe is connected to the first combustion-supporting gas inlet of the dual-fuel burner, and the outlet of the blower is connected to the second combustion-supporting gas inlet of the dual-fuel burner. The outlet of the nitrogen delivery pipe is connected to the hydrogen delivery pipe at multiple points, and an vent pipe is connected to the hydrogen delivery pipe.
[0006] Furthermore, a fire baffle is fixed inside the hot air duct directly opposite the fire outlet of the dual-fuel burner, and a hot air flow gap is formed between the left and right sides and the top of the fire baffle and the inner wall of the hot air duct.
[0007] Furthermore, a pressure sensor and a control valve are sequentially installed on the hydrogen delivery pipe; a solenoid valve is installed on the vent pipe; the signal output terminal of the pressure sensor is connected to the signal input terminal of the controller via a signal connection, and the signal output terminal of the controller is connected to the signal input terminals of the control valve and the solenoid valve via signal connections.
[0008] Furthermore, it also includes a steam tracing pipe, which is fixed side by side with the hydrogen delivery pipe and is in a close proximity to each other. The steam tracing pipe and the hydrogen delivery pipe are covered with heat insulation material.
[0009] Furthermore, it also includes a condensate water seal tank, with drain pipes connected to the low points of the hydrogen delivery pipe and the steam tracing pipe, respectively, and the drain outlets of the two drain pipes are located below the liquid level in the condensate water seal tank.
[0010] Advantages of this utility model:
[0011] 1. The present invention discloses a calcination system for producing cyanuric acid, wherein hydrogen, a byproduct of sodium chlorate production, is used as a clean energy source in the production of crude cyanuric acid, thereby realizing the resource utilization of hydrogen, reducing the amount of natural gas used, and thus reducing the production cost of cyanuric acid products.
[0012] 2. The present invention discloses a calcination system for producing cyanuric acid, wherein by setting a fire baffle in the hot air channel, the frequent damage to the air box in the calcination kiln caused by the high flame temperature is effectively avoided. At the same time, the hydrogen delivery pipe can be replaced with nitrogen in a timely manner before gas supply, after gas supply, and under abnormal conditions, thus ensuring the safe and stable operation of the hydrogen system. Attached Figure Description
[0013] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0014] Figure 1 This is a schematic diagram of the overall structure of Embodiment 1 of this utility model.
[0015] 1. Calcination kiln; 2. Hot air passage; 3. Dual-fuel burner; 4. Hydrogen delivery pipe; 5. Natural gas delivery pipe; 6. Instrument gas delivery pipe; 7. Blower; 8. Nitrogen delivery pipe; 9. Steam tracing pipe; 10. Condensate water seal tank; 11. Drain pipe; 12. Firewall; 13. Pressure sensor; 14. Control valve; 15. Solenoid valve; 16. Controller; 17. Drain pipe. Detailed Implementation
[0016] The present invention will be further described in detail below through embodiments.
[0017] Example: Figure 1 As shown, a calcination system for producing cyanuric acid includes a calcination kiln 1, a dual-fuel burner 3, a hydrogen supply pipe 4, a natural gas supply pipe 5, an instrument gas supply pipe 6, a blower 7, a nitrogen supply pipe 8, a steam tracing pipe 9, and a condensate water seal tank 10. A hot air channel 2 is provided on the calcination kiln 1. The dual-fuel burner 3 is fixedly installed at the end of the hot air channel 2 furthest from the calcination kiln 1. The outlet of the hydrogen supply pipe 4 is connected to the first fuel gas inlet of the dual-fuel burner 3, and the outlet of the natural gas supply pipe 5 is connected to the second fuel gas inlet of the dual-fuel burner 3. By mixing and burning hydrogen as fuel gas with natural gas, the resource utilization of hydrogen is realized, the consumption of natural gas is reduced, and thus the production of cyanuric acid is reduced. To reduce production costs, the outlet of the instrument gas delivery pipe 6 is connected to the first combustion-supporting gas inlet of the dual-fuel burner 3, ensuring that hydrogen and clean air are mixed in proportion for proper combustion. The outlet of the blower 7 is connected to the second combustion-supporting gas inlet of the dual-fuel burner 3, used to deliver hot gas flow and ensure complete combustion of natural gas. The outlet of the nitrogen delivery pipe 8 is connected to the hydrogen delivery pipe 4 at multiple points, enabling timely nitrogen replacement of the hydrogen delivery pipe 4 before gas supply, after gas supply stoppage, and in abnormal situations, ensuring the safe and stable operation of the hydrogen system. An vent pipe 11 is connected to the hydrogen delivery pipe 4. The model of the dual-fuel burner 3 is XRQ-Q / HEF-3.6, manufactured by Xuzhou Combustion Control Research Institute Co., Ltd.
[0018] A fire baffle 12 is fixed inside the hot air duct 2 directly opposite the outlet of the dual-fuel burner 3. A hot air flow gap is formed between the left and right sides and the top of the fire baffle 12 and the inner wall of the hot air duct 2, which effectively prevents the air box in the calcining kiln 1 from being frequently damaged due to the high flame temperature.
[0019] A pressure sensor 13 and a control valve 14 are sequentially installed on the hydrogen delivery pipe 4; a solenoid valve 15 is installed on the vent pipe 11; the signal output terminal of the pressure sensor 13 is connected to the signal input terminal of the controller 16 via a signal connection, and the signal output terminal of the controller 16 is connected to the signal input terminals of the control valve 14 and the solenoid valve 15 via a signal connection; the pressure sensor 13 constantly monitors the pressure inside the hydrogen delivery pipe 4 and transmits the signal to the controller 16. When the pressure is higher than the set value, the controller 16 controls the solenoid valve 15 to open and the control valve 14 to close, performing emergency venting of hydrogen to ensure the safety of the system.
[0020] The steam tracing pipe 9 and the hydrogen delivery pipe 4 are fixed side by side and close to each other. The steam tracing pipe 9 and the hydrogen delivery pipe 4 are covered with insulation material. In order to ensure the safe and stable supply of hydrogen in winter, steam is used to trace the hydrogen delivery pipe 4 to avoid freezing inside the hydrogen delivery pipe 4.
[0021] Drain pipes 17 are connected to the lowest point of the hydrogen delivery pipe 4 and the lowest point of the steam tracing pipe 9 respectively. The drain outlets of the two drain pipes 17 are placed below the liquid level in the condensate water seal tank 10, so that the water condensed in the hydrogen delivery pipe 4 and the steam tracing pipe 9 can be discharged into the condensate water seal tank 10.
[0022] The above are preferred embodiments of this utility model. For those skilled in the art, several improvements and modifications can be made without departing from the principle of this utility model, and these improvements and modifications should also be considered within the protection scope of this utility model.
Claims
1. A calcination system for producing cyanuric acid, characterized in that, It includes a calcining kiln, a dual-fuel burner, a hydrogen supply pipe, a natural gas supply pipe, an instrument gas supply pipe, a blower, and a nitrogen supply pipe. A hot air channel is provided on the calcining kiln, and the dual-fuel burner is fixedly installed at the end of the hot air channel away from the calcining kiln. The outlet of the hydrogen supply pipe is connected to the first fuel gas inlet of the dual-fuel burner, the outlet of the natural gas supply pipe is connected to the second fuel gas inlet of the dual-fuel burner, the outlet of the instrument gas supply pipe is connected to the first combustion-supporting gas inlet of the dual-fuel burner, and the outlet of the blower is connected to the second combustion-supporting gas inlet of the dual-fuel burner. The outlet of the nitrogen supply pipe is connected to the hydrogen supply pipe at multiple points, and an vent pipe is connected to the hydrogen supply pipe.
2. The calcination system for producing cyanuric acid according to claim 1, characterized in that, A fire baffle is fixed inside the hot air duct directly opposite the fire outlet of the dual-fuel burner, and a hot air flow gap is formed between the left and right sides and the top of the fire baffle and the inner wall of the hot air duct.
3. The calcination system for producing cyanuric acid according to claim 1, characterized in that, A pressure sensor and a control valve are sequentially installed on the hydrogen delivery pipe; a solenoid valve is installed on the vent pipe; the signal output terminal of the pressure sensor is connected to the signal input terminal of the controller via a signal connection, and the signal output terminal of the controller is connected to the signal input terminals of the control valve and the solenoid valve via signal connections.
4. The calcination system for producing cyanuric acid according to claim 1, characterized in that, It also includes a steam tracing pipe, which is fixed side by side with the hydrogen delivery pipe and is in a close proximity to each other. The steam tracing pipe and the hydrogen delivery pipe are covered with heat insulation material.
5. The calcination system for producing cyanuric acid according to claim 4, characterized in that, It also includes a condensate water seal tank, with drain pipes connected to the low points of the hydrogen delivery pipe and the steam tracing pipe, respectively, and the drain outlets of the two drain pipes are located below the liquid level in the condensate water seal tank.