A powder rotary drying system for full-flow waste heat utilization of flue gas

Abstract

The present invention discloses a powder rotary drying system that utilizes the full flow of waste heat from flue gas, comprising a rotary drum, the rotary drum being tilted, a driving device being arranged on the outside, a powder pneumatic conveying pipe being arranged on the higher end of the rotary drum, the powder pneumatic conveying pipe being connected to the roasting kiln exhaust outlet and the material bin respectively, and an exhaust dust content treatment device being arranged on the lower end of the rotary drum; the exhaust dust content treatment device comprising a shell, an exhaust gas discharge pipe being arranged on the top of the shell, the exhaust gas discharge pipe extending to the inner cavity of the shell, a discharge valve being arranged at the bottom of the shell, a flow guide cylinder being arranged in the inner cavity of the shell, the flow guide cylinder being sheathed on the outer side of the exhaust gas discharge pipe, a flow guide cavity being formed between the flow guide cylinder and the exhaust gas discharge pipe, a flow guide cone being arranged at the lower end of the flow guide cylinder, the outer diameter of the guide cone decreasing from the top to the bottom component, and a material dropout port being arranged at the lower end of the guide cone. The present invention dries the raw materials by heat exchange with high-temperature exhaust gas, and cools the exhaust gas by the material, thereby eliminating the exhaust gas cooling step used in the original production technology.

Description

Technical Field

[0001] The present invention relates to the field of new energy battery production, and in particular to a powder rotary drying system utilizing the waste heat of full-flow flue gas. Background Art

[0002] Currently, national policies are vigorously supporting the development of new energy vehicles. As an anode material for new energy batteries, lithium carbonate has a promising market prospect. Lithium carbonate can be produced through the lepidolite sulfate method. After lepidolite is mixed with sulfate and calcined at high temperatures, the exhaust gas reaches temperatures of up to 400°C. Because this exhaust contains various components such as SO2, NOx, dust, fluoride particles, and hydrogen fluoride, it cannot be directly used for waste heat recovery, resulting in energy waste.

[0003] In order to cope with normal process production, many companies adopt the exhaust gas first-stage cyclone dust removal process. The exhaust gas after dust removal is cooled by an air cooler. After the exhaust gas temperature is reduced to an acceptable range for the bag dust collector, the exhaust gas is treated by the bag dust collector. Summary of the Invention

[0004] Purpose of the invention: The purpose of the present invention is to provide a powder rotary drying system that utilizes the full flow of flue gas waste heat, dries the raw materials through heat exchange with high-temperature exhaust gas, and cools the exhaust gas through the material, thereby eliminating the exhaust gas cooling link used in the original production technology.

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

[0006] A powder rotary drying system utilizing the full flow waste heat of flue gas comprises a rotary drum, the rotary drum being arranged at an angle, a driving device being arranged on the outside of the rotary drum for driving the rotary drum to rotate, a powder pneumatic conveying pipe being arranged at the higher end of the rotary drum, the powder pneumatic conveying pipe being connected to the exhaust outlet of the roasting kiln and the material bin respectively, and an exhaust dust content treatment device being arranged at the lower end of the rotary drum;

[0007] The exhaust gas dust content treatment device includes a shell, an exhaust gas emission pipe is arranged on the top of the shell, the exhaust gas emission pipe extends to the inner cavity of the shell, a discharge valve is arranged at the bottom of the shell, a guide cylinder is arranged in the inner cavity of the shell, the guide cylinder is mounted on the outside of the exhaust gas emission pipe, and a guide cavity is formed between the guide cylinder and the exhaust gas emission pipe, a guide cone is arranged at the lower end of the guide cylinder, the outer diameter of the guide cone gradually decreases from top to bottom, and a drop port is arranged at the lower end of the guide cone.

[0008] Furthermore, an air-blocking inverted cone is provided above the blanking port, with the large-diameter end of the air-blocking inverted cone facing downward and forming an annular gap with the diameter of the blanking port.

[0009] Furthermore, the powder pneumatic conveying pipeline is provided with a flue gas heating device for introducing high-temperature flue gas into the powder pneumatic conveying pipeline.

[0010] Furthermore, the powder pneumatic conveying pipeline is provided with a water mist spray cooling device for spraying cooling water mist into the powder pneumatic conveying pipeline.

[0011] Furthermore, the driving device includes a support base, a driving motor is provided on the support base, and the driving motor is connected to the rotating cylinder through a transmission mechanism.

[0012] Furthermore, the driving motor adopts a variable frequency speed regulating motor.

[0013] Beneficial effects:

[0014] The present invention adopts the technology of heat exchange drying between high-temperature exhaust gas and raw materials, and cools the exhaust gas through the materials, which can reduce the additional heat required for drying the materials and reduce the additional power loss caused by the use of air coolers for cooling in the existing technology. Since the exhaust cyclone dust removal system used in the existing production process is eliminated, the device of the present invention realizes that the exhaust gas does not need dust removal and the full air volume enters the rotary drying system;

[0015] The present invention optimizes the feeding mode of the rotary drying system, eliminates the open feeding mode, and realizes closed feeding through the powder pneumatic conveying pipeline, which greatly reduces the impact of system air leakage on the production process;

[0016] The present invention adopts an exhaust gas dust content treatment device to treat exhaust gas dust at the end, thereby reducing the amount of dried materials carried out by the exhaust gas and reducing subsequent material collection and transportation devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic structural diagram of the powder rotary drying system that utilizes the full flow waste heat of flue gas according to the present invention.

[0018] Figure 2 This is a structural diagram of the exhaust gas dust content treatment device.

[0019] In the figure: 1- exhaust gas emission pipe; 2- guide cylinder; 3- shell; 4- discharge valve; 5- rotary cylinder; 6- guide cone; 7- powder pneumatic conveying pipeline; 8- flue gas reheating device; 9- driving device; 10- water mist spray cooling device; 11- guide chamber; 12- wind-blocking inverted cone. DETAILED DESCRIPTION

[0020] The present invention will be further explained below with reference to the accompanying drawings.

[0021] like Figure 1As shown, the present invention discloses a powder rotary drying system utilizing full-flow waste heat from flue gas, comprising a rotating drum 5, which is arranged at an angle. A drive device 9 is disposed outside the rotating drum 5 for driving the rotating drum 5. The drive device 9 is configured to rotate the rotating drum 5. The drive device 5 includes a support base, on which a drive motor is disposed, and the drive motor is connected to the rotating drum via a transmission mechanism. The transmission mechanism can employ a gear transmission mechanism or a belt drive structure, and the drive motor employs a variable frequency speed motor, which facilitates adjustment of the rotation speed of the rotating drum 5.

[0022] A powder pneumatic conveying pipe 7 is provided at the higher end of the rotary cylinder 5. The powder pneumatic conveying pipe 7 is sealedly connected to the rotary cylinder 5. The powder pneumatic conveying pipe 7 is respectively connected to the roasting kiln exhaust gas outlet and the material bin (not shown in the figure). Material transportation is achieved through the powder pneumatic conveying pipe 7 using the roasting kiln exhaust gas. The powder pneumatic conveying pipe 7 is provided with a flue gas reheating device 8. The flue gas reheating device 8 is used to introduce high-temperature flue gas into the powder pneumatic conveying pipe. The flue gas reheating device uses a natural gas burner. The natural gas burner has a high-temperature flue gas pipe lined with refractory material as a combustion furnace. The flame burns directly in the high-temperature flue gas pipe, and the heat of combustion is directly mixed with the high-temperature flue gas. The natural gas flow rate of the reheating device is controlled according to the exhaust gas temperature of the drying device. The powder pneumatic conveying pipe 7 is also provided with a water mist spray cooling device 10. The water mist spray cooling device 10 includes a water mist nozzle for spraying cooling water mist into the powder pneumatic conveying pipe.

[0023] The lower end of the rotary cylinder 5 is provided with an exhaust dust treatment device; the exhaust dust treatment device is used to separate the exhaust gas that has completed heat exchange from the dust particles in the material. Figure 2 As shown, the exhaust gas dust content treatment device includes a housing 3, with an exhaust gas discharge pipe 1 disposed on the top of the housing 3, which extends into the housing cavity. A discharge valve 4 is disposed at the bottom of the housing 3, and a guide cylinder 2 is disposed in the housing cavity. The guide cylinder 2 is sleeved on the outside of the exhaust gas discharge pipe 1, forming an annular guide cavity 11 between the guide cylinder 2 and the exhaust gas discharge pipe 1. A guide cone 6 is disposed at the lower end of the guide cylinder 2, and the outer diameter of the guide cone 6 gradually decreases from top to bottom. A drop opening is disposed at the lower end of the guide cone 6. A wind-blocking inverted cone 12 is disposed above the drop opening, with the large diameter end of the wind-blocking inverted cone 12 facing downward, forming an annular gap with the diameter of the drop opening.

[0024] The exhaust gas dust content treatment device can realize the top surface air intake mode by setting the guide cylinder 2, the guide cone 6 and the annular guide cavity 11 formed between the guide cylinder 2 and the exhaust gas discharge pipe 1. This air intake mode is different from the 270° vortex air intake implementation mode of the traditional cyclone dust collector side, which helps to better separate the exhaust gas that has completed heat exchange from the dust particles in the material. By setting a drop port at the lower end of the guide cone 6 and setting an air-blocking inverted cone 12, on the one hand, it facilitates the normal discharge of dust particles, and at the same time prevents the exhaust gas from flowing back through the drop port.

[0025] When the powder rotary drying system is working, the high-temperature exhaust gas discharged from the roasting kiln is used to transport the material to be dried through the powder pneumatic conveying pipe 7 to the rotary cylinder 5. The rotary motion of the rotary cylinder 5 continuously turns the material and passes through the rotary cylinder 5. The material and the exhaust gas are heat-exchanged in the rotary cylinder 5. The speed of the rotary cylinder 5 is adjusted by the variable frequency speed regulating motor to control the drying degree of the material and the temperature of the exhaust gas after drying. In the case of exhaust gas temperature fluctuations, the drying heat is adjusted by the flue gas heat supplement device 8 to ensure the drying effect. The dried material and the cold The cooled exhaust gas enters the shell 3 of the exhaust gas dust content treatment device, rises along the outside of the guide cone 6 and the guide cylinder 2, then enters the inside of the guide cone 6 through the guide cavity 11, and is discharged through the exhaust gas discharge pipe 1. Most of the material falls to the bottom of the shell 3 under the action of gravity and is then discharged through the discharge valve 4. Some dust particles in the material fall to the discharge valve 4 due to the obstruction of the outer wall of the guide cone 6. The remaining dust particles follow the airflow through the guide cavity 11 into the guide cone 6, and then fall to the discharge valve 4 due to the obstruction of the inner wall of the guide cone 6. In the case of a rotary drying system without material cooling of the exhaust gas, a water mist spray cooling device 10 is used for water mist cooling to maximize the control of the exhaust gas temperature and system air leakage.

[0026] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A powder rotary drying system utilizing the full flow waste heat of flue gas, characterized by: It includes a rotary cylinder, which is tilted, and a driving device is arranged on the outside of the rotary cylinder to drive the rotary cylinder to rotate. A powder pneumatic conveying pipe is arranged on the higher end of the rotary cylinder, and the powder pneumatic conveying pipe is connected to the roasting kiln tail gas discharge port and the material bin respectively. An tail gas dust content treatment device is arranged on the lower end of the rotary cylinder; The exhaust gas dust content treatment device includes a shell, an exhaust gas discharge pipe is provided on the top of the shell, the exhaust gas discharge pipe extends to the inner cavity of the shell, a discharge valve is provided at the bottom of the shell, a guide cylinder is provided in the inner cavity of the shell, the guide cylinder is sleeved on the outside of the exhaust gas discharge pipe, a guide cavity is formed between the guide cylinder and the exhaust gas discharge pipe, a guide cone is provided at the lower end of the guide cylinder, the outer diameter of the guide cone gradually decreases from top to bottom, and a drop port is provided at the lower end of the guide cone; An air-blocking inverted cone is arranged above the blanking port, with the large-diameter end of the air-blocking inverted cone facing downwards and forming an annular gap with the diameter of the blanking port.

2. The powder rotary drying system utilizing the full flow waste heat of flue gas according to claim 1 is characterized in that: The powder material pneumatic conveying pipeline is provided with a flue gas heating device for introducing high-temperature flue gas into the powder material pneumatic conveying pipeline.

3. The powder rotary drying system utilizing the full flow waste heat of flue gas according to claim 1 is characterized in that: The powder material pneumatic conveying pipeline is provided with a water mist spray cooling device for spraying cooling water mist into the powder material pneumatic conveying pipeline.

4. The powder rotary drying system utilizing the full flow waste heat of flue gas according to claim 1 is characterized in that: The driving device includes a support base, a driving motor is arranged on the support base, and the driving motor is connected to the rotary cylinder through a transmission mechanism.

5. The powder rotary drying system utilizing the full flow waste heat of flue gas according to claim 4 is characterized in that: The driving motor adopts a variable frequency speed regulating motor.

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