Improving Nickel Sulfate Drying with Vibrating Fluidized Bed Dryer Technology

Technical solution introduction

1. Material overview

Nickel sulfate has three types: anhydrous, hexahydrate and heptahydrate. Most of the products are hexahydrate, with two variants: α-type and β-type. The former is a blue tetragonal crystal, and the latter is a green monoclinic crystal. When heated to 103°C, it loses six crystal waters. It is easily soluble in water, slightly soluble in ethanol and methanol, and its aqueous solution is acidic, slightly soluble in acid and ammonia, and toxic. It is mainly used in electroplating industry, pharmaceutical industry, inorganic industry, printing and dyeing industry, etc.

2. Overview of nickel sulfate drying solution

The material dried this time is nickel sulfate, which is highly acidic and corrosive. In view of this feature, our company has upgraded and improved the equipment manufacturing. The upper and lower boxes of the vibrating fluidized bed and the inner wall are all made of 3mm fiberglass, the vibration plate is made of special nickel plate with duck tongue holes, and the exhaust gas is all made of high temperature and corrosion resistant fiberglass. The support frame and support pipe are also made of carbon steel Teflon material. In order to achieve good emission effects, the bag filter bag is made of special materials, which are extremely acid-resistant. Even the frequency conversion air adjustment of the induced draft fan is made of FRP. This process solves the problem of high temperature and high corrosion encountered in the material drying process.

3. Principle of nickel sulfate drying scheme

The material enters the machine from the feed port, and jumps forward on the air distribution plate under the excitation force provided by the vibration motor or other means. At the same time, the air is filtered and heated to a certain temperature, and enters the lower air chamber of the dryer from the air port. Under the dual effects of vibration force and hot air flow uniformly blown by the air distribution plate, the material is in a suspended state and in contact with the hot air flow. There is intense turbulence between the material particles and the heat medium, which strengthens the heat and mass transfer process. The dried product is discharged from the discharge port, and the evaporated water and exhaust gas are discharged into the atmosphere after the dust is recovered by the cyclone separator. The lower bed provides a stable wind chamber with a certain pressure for the bed layer. Adjust the induced draft fan to keep a slight negative pressure on the upper part of the bed material in the upper box to maintain a good drying environment and prevent dust leakage.

4. Characteristics of nickel sulfate drying scheme

1). The material is heated evenly, the heat exchange is sufficient, the drying intensity is high, and it saves about 30% energy compared with ordinary dryers. The vibration source is driven by a vibration motor, which has balanced operation, convenient maintenance, low noise and long service life. The fluidization is stable, without dead corners and blow-through phenomena. It has little damage to the surface of the material and can be used for drying fragile materials. Even when the material particles are irregular, it does not affect the working effect.

2). The fully enclosed structure effectively prevents cross-contamination between the material and the air, and the working environment is clean. It has good adjustability, wide adaptability, and the thickness of the material layer, the speed of movement in the machine, and the amplitude change can all be adjusted steplessly.

3). Due to the application of vibration, the small fluidization gas velocity can be reduced, thereby significantly reducing the air demand, thereby reducing the entrainment of the dust layer, and the matching heat source, fan, cyclone separator, etc. can also be reduced in size accordingly, the complete set of equipment is reduced, and the energy saving effect is obvious. The retention time in the machine can be easily changed by adjusting the vibration parameters. Its plug flow operation reduces the requirements for material particle size uniformity and regularity, making it easy to obtain uniform dry products.