Process flow diagram

DESCRIPTIONS

◎ Spray drying is a method of applying systematic technology to material drying. The production equipment of this method is simple, the process is easy to realize, the solution and emulsion can be quickly dried into powder or granular products, evaporation and washing procedures can be omitted, the production efficiency of products can be improved, the cost can be saved, and mass production can be realized.

◎ Spray drying method has been widely used in the field of lithium battery material preparation. Through the spray drying tests of different anode and cathode materials (Ferrous lithium phosphate, lithium carbonate, etc.) in recent years, coupled with the new requirements constantly put forward by users and the absorption of new foreign technologies, we can select and optimize the process design, and produce high-quality battery materials with high energy efficiency and low cost.

PRINCIPLE

◎ After filtering and heating, the air enters the air distributor at the top of the dryer, and the hot air enters the drying chamber evenly in a spiral shape. The feed liquid passes through the high-speed centrifugal atomizer at the top of the tower body, and is (rotated) sprayed into extremely fine mist-like liquid beads, which can be dried into finished products in a very short time by cocurrent contact with hot air. The finished product is continuously output from the bottom of the drying tower and the gas-solid separator, and the waste gas is exhausted by the induced draft fan.

FEATURES

◎ The drying speed is fast, and the surface area of the feed liquid is greatly increased after atomization. In the hot air flow, 95%~98% of water can be evaporated instantly, and the drying time only takes a few seconds, which is especially suitable for drying heat-sensitive materials.

◎ The product has good uniformity, fluidity and solubility, high purity and good quality.

◎ The production process is simplified and the operation and control are convenient. The liquid with moisture content of 40~60% (special materials can reach 90%) can be dried into powder products at one time, and there is no need to crush and screen after drying, thus reducing production procedures and improving product purity. The particle size, bulk density and moisture content of products can be adjusted by changing operating conditions within a certain range, and the control and management are very square.

APPLICATION

Suitable for Ferrous lithium phosphate, lithium titanate and other liquid and slurry battery materials.

TECHNICAL PARAMETERS

◎ The combination of raw material tank, clean water tank and reversing valve can be used and cleaned regularly according to the characteristics of materials, so that the sediment can be treated in time to ensure the continuous and normal production of the system.

◎ The feed pump adopts frequency conversion control to feed stably, which is interlocked with the exhaust temperature of the drying tower to ensure the moisture requirement of the product.

◎ The high-speed centrifugal atomizer can select the rotating speed according to the characteristics of battery materials. Unique labyrinth seal structure is adopted to avoid leakage of lubricating oil. At the same time, a water cooling device is set to protect the normal operation of the atomizer and ensure the continuous operation of the atomizer for a long time.

◎ The cold air is heated after being treated by the middle and low efficiency air filter, and then it is treated by the high temperature resistant air filter and enters the drying room, so as to ensure the cleanliness of the drying medium and prevent the product from being polluted.

◎ According to the characteristics of battery materials, a special hot air distributor was adopted, which was designed by our company after absorbing the structural essence of foreign spray towers. It is characterized in that the hot air enters the drying tower uniformly by the special distribution structure, so as to prevent turbulence and turbulence, and make uniform and full contact with the droplets atomized by high pressure, so that it is not easy to produce contact dead angles and improve the consistency of the drying environment of materials.

◎ The drying chamber is made of mirror stainless steel plate, the welding seam is shielded by argon, and the welding surface is polished by high-precision mirror (the internal surface smoothness Ra is less than or equal to 0.8), so as to ensure that the working surface is smooth and flat, without cleaning dead angle, and has excellent corrosion resistance. At the same time, the drying tower is provided with a quick-opening cleaning port, which is convenient for disassembly and cleaning, and fully meets the requirements of battery material production specifications. Strictly calculate the atomization angle of atomizer and enlarge the diameter of drying chamber reasonably to prevent the material from sticking to the wall during pre-drying; The taper of the discharging cone in the drying chamber is adjusted, the included angle is adjusted to 50, and a pneumatic vibrator is set to fully consider the smooth discharging of materials.

◎ During the whole drying process, in order to ensure the purity of the product, the product should be in contact with metal materials as little as possible, and the process should be short, and the bottom of the drying tower is not discharged, and the density of battery materials is too high. In order to ensure that the materials are not graded and the products are smoothly transported to the bag dust collector, a deflector is specially set at the corner of the drying tower to ensure that the materials are not deposited, and a quick-opening cleaning hole is set at the corner.

◎ Due to the high exhaust temperature, the bag dust collector is equipped with a reliable cold air system to prevent the bag from overheating and dew condensation. When the exhaust air temperature can't be effectively lowered, the bypass system is turned on, so that the high-temperature flue gas can directly flow out of the dust collector from the bypass system to ensure the safety of the filter cloth. The bypass system adopts automatic temperature control and has technical measures to prevent the valve from being closed loosely or not being opened due to dust accumulation.

◎ In order to ensure the stability of product quality, the system adopts interlocking program control mode. Ensure that the normal operation parameters of the system are not affected by human and external factors, and adopt excellent industrial control configuration to ensure the high reliability of equipment operation.

TECHNICAL PARAMETERS