Machines design

Reminder
As described in processes, the output of a shot blasting machine with wheels depends essentially on the concept, the size and the number of wheels used, associated with a projectile well defined.
As a matter of interest, we remind the basis criteria linked to the output of a blast wheel and which are:
- the speed of rotation of the blast wheel rotor,
- the orientation of the blast wheel projection,
- the distribution of the trajectories on the part to treat,
- the quantity of abrasive projected per unit of time,
- the quality and granulometry of the abrasive used.

Type of blast wheel
In order to obtain the projection of a certain quantity of abrasive in a required direction and with a given energy, all the constitutive elements of the blast wheel are to take into account such as:
- the number of flasks,
- the shape and the number of pallets,
- the distribution cage,
- the auxiliary blast wheel,
- the feeding mode of the nozzle,
- the driving system.
The blast wheel is the main element of the shot blasting machine and thus one will have to pay a particular attention to it because it is responsible of the result and the output. The number of blast wheels that have to fit a machine depends on its own covering power, on the shape and the dimensions of the parts to treat. It is preferable to choose the configurations with a minimum number.

Shot blasting machines

Design of the machines
The design of a shot blasting machine with wheels depends on:
- the type and the shape of the product to treat,
- the weight and the volume of the product to treat,
- the feeding or handling system,
- the output and the production to obtain.
The machine can be independent and specific to the treatment of a product, but can also forms part of a production line and thus be linked to its constraints.
As a consequence, the machines are very varied as well regarding their design principles as their dimensions and powers. They can be adapted to a type or a range of defined products, or they can be polyvalent and universal for the treatment of varied products.

Types of machines
They are machines based on different principles: (see schematics)

- in bulk treatment machines for small and medium forge and foundry parts which can stand shocks. The parts submitted to the shot are mixed and returned in a tumble, a drum, or with a jointed or rubber metallic band .

- turntable machines for series of fragile small and medium parts, or a unique and voluminous part from diverse origins.
They can be fitted with turning systems or a putting into rotation through satellites of the parts to treat.

- tunnel machines for a continuous treatment of parts conveyed on endless conveyor belts, rolls or driving diabolos. These machines are very used for founding and for the treatment of sheets, of "streamlined" irons or rolling products before painting.

- monorail machines for the treatment of charges suspended to an overhead conveyor in continuous or discontinuous cycle, of parts isolated or grouped together in clusters. These machines called "universal" are suitable for all kinds of products even if they are fragile (see picture opposite).

- special machines for the treatment of specific iron and steel products such as steel wires (at put on or in bundle), rods, pipes, barrels, rolling mills cylinders and the "shot peening" treatments.