Type of blasting machine with a rotating barrel.
The parts which are to be cleaned are tumbled in a rotating barrel and covered with abrasive from fan-shaped blasting beams in the blast cleaning wheels. The drum shell has holes in it so that the abrasive, sand and other cleaning residues can fall into the collection hoppers below.
The abrasive and sand are separated in a special separating system, ruined abrasive is taken out, the rest is cleaned and sent back to the blast cleaning wheels via bucket conveyors to be used for a new cycle. Dedusting is important so that a lubricating effect which would have a negative effect on the cleaning is not created.
classic version of this kind of machine with vertical rotating barrels and three blast cleaning wheels is shown schematically in Fig. 1, Wheelabrator. Rotating barrel blasting machines are operated in batches, whereby the barrels of some machines can also be tilted after loading. The batch weight varies between 500 and 6,000kg depending on the model and size.
Another type which is also used frequently is the machine with a troughed belt barrel (Fig. 2, Wheelabrator). Here, the items which are to be cleaned are placed in a trough-shaped storage space which is formed by a continuous rubber or steel belt (Fig. 3, Wheelabrator and 4). The blast cleaning wheels shoot the abrasive onto the castings which are tumbled in the trough. At the same time, the trough itself is constantly emptied of sand and abrasive through a rolling movement which causes the residues to fall through the holes in the belt into the corresponding separating equipment. Such a batch-operated system can be expanded to create a fully automated system using appropriate peripheral equipment.
In contrast to the machines which are loaded in batches, there are also machines with a continuous flow of the abrasive (continuous flow barrel blasting machines). Various constructions are available on the market, such as machines with conical or tilted barrels, the same with tilted troughed belt barrels or with double barrels and blasting units in a stationary middle part. The castings are turned evenly by the barrel movement; in addition, drive rails on the drive belt ensure that the abrasive is tumbled thoroughly. The loading of the input barrel and the output zone with abrasive separation can be designed according to requirements.