How to choose the appropriate abrasives’ recovery and transport system for your blasting hall?
27.02.2017
The investment costs for building a blasting hall are mainly influenced by the selected recovery and transport system for abrasives, respectively by the chosen ventilation solution.
Opting for abrasive types that can be reused automatically justifies the investment in high-performance recovery, transport and cleaning systems for them.
Usually choosing one type of abrasive instead of another is based on the type of parts to be processed. Steel Grit, Electro-corundum and Glass Beads appear to be the most common options in many cases.
The recovery and transport equipment for abrasives includes mechanical and/or pneumatic systems that combine horizontal and vertical transport, in both continually or discontinuously manners.
The discontinuous system refers to when the operators have to manually or mechanically collect the abrasive material after the blasting process and to redirect it to the transport and recovery area, waiting for the material to be reintroduced in the process for further blasting cycles.
Usually in such situations the blasting systems include storage reservoirs of high capacity, able to insure the working autonomy for one operational cycle.
The continuous system refers to the cases when the recovery and transport of abrasives is automatically done during the blasting process. This means that the blasting operation does not need to be interrupted as in the case of discontinuous systems.
This type of solution is recommended when working in 2 or 3 shifts, or whenwhen willing to act at full capacity.
In case of small cabins one can opt for using pneumatic systems. Their collecting capacities are far smaller than the ones of mechanical systems therefore being appropriate when the working volume is smaller.
The collection and transport of abrasive is done while using a vacuum unit. Separating the dust from the abrasive material is organized with the help of a cyclone dust separator. In some cases more complex systems are recommended if there is a particular cleaning need.
It is very important for this separator to properly function as it will influence not only the quality of the blasting operation itslef, but also the lifetime of the entire equipment.
Usually the pneumatic vacuum units are more powerful than others, but they have the disadvantage that they work with high debits of compressed air.
In the case of many industrial applications it is recommended to use mechanical systems, which combine the recovery and the horizontal plus vertical transportations.
The solutions designed by Minex usually integrate a bucket type elevator with standard capacities of 3 m3/h and 12 m3/h. Other capacities are also available by request.
The simplest recovery systems are the ones with recovery units placed directly in the elevator (4AO systems). They usually do not include a mixing spindle, or they might have one of small capacity, which does not function independently.
There are also mixing spindles with transverse receivers (4A1 systems) or with conveyor belts (usually of 7 m length). In shipyards one might opt for longer versions so the conveyor belts that are usually of 30 to 40 m.
In case of automatic recovery, the conveyor belts are set in the floor and connected to the transverse receivers from where the abrasive is overtook within the elevator.
All mentioned solutions have dosage systems for abrasive recovery, which are extremely useful especially in the case of discontinue blasting operations. The abrasive material is directed and stored above the recovery unit, within the dosage system, from where it will be transported and recharged for new blasting cycles.
For all these mechanical systems special foundations or floor uplifts might be needed in the blasting hall.
On the top of the recovery systems, protection units are set in order to avoid the unwished elements getting into the equipment.
After the abrasive is processed in the elevator, it has to be cleaned of all dust or other types of impurities so that it becomes reusable for a specific set of cycles.
After the cleaning process, the abrasive is collected in a storage unit from which the blasting installations are getting supplied.
There are more cleaning systems available on the market:
separator with vibrating filters (there is no need to daily clean those as in the case of using separators with fixed filters)
dust cleaning systems with filters that are to be cleaned with compressed air
The separated filter offers the possibility the better control the level in which the abrasive is cleaned during the process.
Minex developed also dual cleaning systems allowing the use of different types of abrasive. This one is collected in the unique recovery and transport unit, and the cleaning process is done with the help of the following integrated elements:
magnetic separator plus the appropriate demagnetizer
separators and dust extraction filters
individual storage units and blasting installations for each type of abrasive material in part
Cleaning the abrasive is probably the most important operation within the entire process because it directly influences the efficiency of the blasting operation and the lifetime of the different components of the equipment.
The quality of each part of the entire assemblage and the overall design and implementation of the system are crucial as they will have a direct impact on the lifetime of the overall solution and on the final results of the blasting process.
