Sand blasting cabin or sand blasting room

General points
The shot blasting installations with a manual free jet, with an internal operator, more commonly called "sand blasting cabins" or "sand blasting rooms" are made of 4 sets which constitute very distinct functions. They are:
1) - the treatment room or work enclosure.
2) - the abrasive recovery and transport system.
3) - the abrasive recycling and treatment machinery.
4) - the set of ventilation and filtration of dusty air.
These various elements are governed by the rule book and some "official recommendations" that one must respect. They are detailed hereafter under the form of chapters.

The enclosure

Constitution and dimensions
The abrasive projection through compressed air has some dangers due to the high speed of the grains projected. The treatment operations have thus to be done in a closed enclosure in order to protect the environment.
In one hand, the enclosure ensures the treatment isolation, the recovery of dust and abrasives. In the other hand, it encloses the appliances for protection, lighting, projection and handling. It can be made from sheet metal panels folded and gathered through bolting, or from maçonnées partitions or various existing structures.
These dimensions will be adapted to the most common parts to treat, while taking into account the operator comfort, but without calculating ever the ideal dimensions in relation to the exceptional part (rule of the 80%).
In practice, about 1000 to 1500 mm are added around the part to treat and 1000 to 2000 mm above the part and its possible truck, according to the sides to treat. An over-proportioned enclosure leads to an extra cost of useless manufacturing, recovery, ventilation and energetic consumption.

The access doors
The enclosure can be a dead end-type or a crossing-type.
The access doors can be equally:
- stiff double doors,
- folding dutch doors,
- sectionnel horizontal,
- folding horizontal, (see picture opposite)
- sliding simple or double panels,
- with a metallic shutter (if the sealing is particularly cared).

The control of these doors can be manual or motorized, with a closing contact allowing the start of the projection in the position doors closed. The operator door has to be fitted with a protected peephole, a closing system type anti-panic and a safety unit of light (for big cabins, a door has to be allowed every 10 meters).

The internal protection
The walls and doors of the enclosure have to be covered with rubber curtains, free if possible (not stuck) in order to cushion the rebounds and protect their surfaces from the abrasive aggressions. This anti-abrasive protection eliminates also the impacts sounds resonating on the sheet metal panels.

Lighting: level of lighting
The work quality depends partly of the visual appreciation that the operator has of the efficiency of his action on the surface to shot blast. Moreover, the part to treat, its support or the sand blasting hose, in a particularly dusty atmosphere, are some obstacles which may cause the operator fall. The vision through the hard hat window is limited and thus the lighting of the enclosure has to be particularly efficient and correspond to the "Lighting General Measures NF X 35-103", which sets for this kind of work the lighting level to 300 lux.

Lighting: the lights
The main lighting, located on the ceiling preferably, has to be dust-tight, resist to thermal shock and mechanical shocks caused by the abrasive projections. Its resistance must correspond to the protection index IP 659. The transparent screen has to resist to abrasion.
In the case of voluminous parts that could create shade areas, it is necessary to install an additional side lighting, or in the pit according to the work that has to be made.