GENERAL CHARACTERISTICS AND FIELDS OF APPLICATION

The "FLASH SYSTEM" is an advanced technology for reaction, drying and granulation which is based on the principle of mechanical centrifugation to create, inside the equipment, the conditions of product in a dynamic and turbulent thin layer, in atmosphere of air, gas, vapours or under vacuum. These fundamentals are applied at best in the construction series of industrial machines operating in continuous which are included in VRV production range.
The basic structure, which is common to all models, consists of a horizontal cylindrical stator complete with a thermal jacket, inside which a cylindrical rotor coaxial with the stator operates at high speed. The rotor is equipped with adjustable centrifugation and agitation devices, and it is supported by rolling bearings placed at the shaft ends.The fed material, either liquid or solid, undergoes two main combined and synergic actions by the rotor:

• the centrifugal force throws it to the exchange wall and
• the energetic mixing effect of the mixing devices, with which the rotor is equipped, removes it continuously and makes it move forward in thin dynamic and turbulent layers along the stator hot wall.

The advantages of operating with a thin layer of product lies in a very good coefficient of thermal exchange, very low wall contact times and a completely homogeneous treatment. Consequently, it is possible to reach a high temperature difference without any danger of product deterioration and wall dirtying, and to also process heat sensitive products.

To obtain the excellent results we have mentioned briefly, VRV made use of up-to-the-minute design techniques and of the considerable experience gained in the field of top quality mechanic constructions, together with a deep and thorough knowledge of construction materials. The production programme comprises the

• Flash Drier
• Ecoflash
• Flash Reactor.

FLASH DRIER
It is a high-speed centrifugal dryer-granulator with a very wide range of applications and with running conditions that can be optimized depending on the specific characteristics of the treated product and on the operation thermal conditions.

Form of treated products
Solutions, suspensions, slurries, filter cakes, granulates, powders, crystals, at variable rheology and moisture.

Critical state of the treated products
Thermal sensitivity-instability, transient plastic rheology, chemical aggressiveness, toxicity, soiling power, abrasive property, high viscosity.

Operations that can be carried out simultaneously
Dosing of powders and liquids, concentration, granulation, coating, reactions in heterogeneous and homogeneous phase, sterilization, mixing, homogenizing.

Process main characteristics and conditions

• Process time: 15/300 sec
• Temperatures of heat exchange fluid and of process gas: 40/300°C
• Tip and centrifugation speed: up to 35 m/sec
• Evaporative capacity from 50 to 2000 l/h
• Granulometric range: 5-3000 micron.

Plant configuration

• Closed cycle system
• Open cycle system
• Under vacuum
• Under inert atmosphere

        
Technological advantages
Reduced dimensions, minimum maintenance, high energy yield (thermal load lower than 750 kCal/l of evaporated water), low process costs, process flexibility, effluents scrubbing, easy operation and cleaning, no environmental pollution or product contamination.

Some processes carried out
Organic and inorganic salts, polymeric resins, organic and inorganic pigments and dyestuff, silicates, aluminates, soda, potassium carbonate, antibiotics, stearates, amides, esters, fertilizers, phosphates, modified starch, acrylates, enamels, clay, talc, amino acids, CMC, PVC, sugar syrups, molasses, distilling slops, blood, fish flour, fodder from various by-products, organic waste, primary alcohol sulfate (PAS), sodium sulphonate (LAS).

Testing Room 
In  the VRV testing room, pilot plants of different size and configuration are available for tests on products and materials and for process evaluations. These plants, implemented by a chemical - physical laboratory and with the support of technical personnel, are at the disposal of VRV customers to carry out tests jointly, both in VRV premises and at the Customer's production unit. For reaction, drying and granulation trials the following pilot plants are available:

• Under vacuum
• Blanketed, either co-current or countercurrent
• Atmospheric countercurrent
• Atmospheric co-current.

To create the plant configuration which best meets the process requirements, several complementary skid-mounted equipment are available, such as:

• Dosing units for powders, pastes and liquids
• Separation cyclones
• Sleeve filters
• Vibrating screens
• Fluid bed
• Heating and cooling unit.