Definition
Explosion-proof disperser is an industrial mixed dispersion equipment specially designed for handling flammable and explosive materials. On the basis of conventional dispersers, it is designed and protected to ensure safe operation in hazardous environments containing flammable gases, vapors or dust, preventing combustion or explosion caused by mechanical sparks, static electricity or high-temperature surfaces.
Principle
The working principle of an explosion-proof disperser is based on mechanical fluid mechanics. Its core component, the high-speed rotating dispersion disc (or rotor-stator structure), is driven by a motor to generate strong shear forces and turbulence. When the material passes through the narrow gap, it is subjected to strong mechanical and hydraulic shear action, so as to achieve the refinement, uniform dispersion and mixing of solid particles in the liquid medium. Its explosion-proof safety is mainly achieved through the following methods: the use of explosion-proof or safety-enhanced explosion-proof motor to prevent the leakage of electric sparks; Use non-ferrous materials for parts that may generate frictional sparks; Adopt electrostatic conduction design; Strictly control the surface operating temperature of the equipment below the ignition temperature of hazardous materials.
Measurement and performance evaluation methodology
The evaluation of the performance of the explosion-proof disperser mainly focuses on two aspects: dispersion effect and safety compliance. Dispersion can be quantified by measuring the particle size distribution of the treated material (e.g., using a laser particle size meter), dispersion stability (e.g., standing to observe delamination time or determining zeta potential), and viscosity uniformity. Its explosion-proof performance is evaluated strictly according to relevant standards, such as China's GB 3836 series standard or the international IEC 60079 series standard. These standards specify the explosion-proof type of equipment (e.g., flameproof "d", enhanced safety "e"), explosion-proof class (e.g., IIB T4), strength testing of protective enclosures, measurement of gap and length of joint surfaces, and temperature group testing to ensure safe use in designated hazardous areas.
Influencing factors
The final dispersion effect and operation safety of the explosion-proof disperser are affected by multiple factors. In terms of process parameters, the linear speed, dispersion time, material feeding sequence and temperature control of the dispersion disc are the keys. Structural factors include the shape and diameter of the dispersion disc, the stator-rotor clearance design, and the shape of the tank. Material properties, such as initial particle hardness, slurry viscosity and solids content, also directly affect dispersion energy consumption and results. At the safety level, the explosive characteristics of materials (such as minimum ignition energy and ignition temperature), the division of on-site hazardous areas, and the matching degree of equipment explosion-proof levels with on-site conditions are the core factors that determine safe operation.
Applications
This equipment is widely used in material preparation processes where there is a risk of flammability and explosion. In the coatings and inks industry, they are used to disperse resins and pigments containing organic solvents. In the chemical field, it is used in the production of pesticide preparations, adhesives and some synthetic materials. In the new energy industry, it is used for the preparation of lithium battery electrode slurry. In addition, it is also used in the production of dyes, pigments and some food additives such as powdered fats and fats. Its core value is to realize the efficient and refined dispersion of materials under the premise of ensuring the intrinsic safety of the production process.
Key points to consider in selection
Selection is a systematic process that requires a comprehensive trade-off between technical parameters and safety requirements. First, it is necessary to clarify the process requirements, including processing volume, target particle size, viscosity range and capacity. Secondly, it is necessary to strictly evaluate the safety conditions, confirm the hazardous area level (such as Zone 1 or Zone 2), the types of explosive substances present (IIA, IIB, IIC) and their temperature groups (T1-T6), and select equipment corresponding to the explosion-proof class and temperature group accordingly. The equipment itself needs to pay attention to whether its power and speed range meet the process shear strength requirements, whether the material is corrosion-resistant, and whether it has the necessary safety accessories such as temperature monitoring and inert gas protection interfaces. Finally, the equipment manufacturer needs to provide certification documents that meet the applicable explosion-proof standards, which is a necessary basis for safety selection.