Wet sandblasting

Reminder
It has been used for several years and has become compulsory with the new European directives on "environmental protection" dated January, 1st, 1995. Wet sandblasting is a sandblasting "without dust" because the vector remains compressed air (see heading wet process).

Principle
A water spray is created at the level of the abrasive shot in order to reduce dust emission (90%) and abrasive dispersion through:
- a spraying annular collar set around the nozzle,
- a nozzle carrier which feeds with water the nozzle air/ abrasive shot,
- a special nozzle fed in periphery by a water supply.
When they are adapted to low pressure tanks, these systems make it possible to obtain softer treatments for which water is considered as a shock absorber.

Applications
- in the building industry, for cleaning on natural stone, concrete, brick, coatings, plasters, and for the cleaning of ancient monuments, churches, and other ancient works,
- in restoration for the sanding of ancient furniture,
- and anywhere the pollution reduction takes first place.

Pipe inner treatment

General points

Pipes inner treatment has been considered for long time as a tricky problem but has been facilitated thanks to the creation of specific systems. They are mainly based on 2 principles:
- static nozzle system,
- dynamic nozzles system.

Static nozzle system
A coniform jet deflector made of a very resistant material to abrasion is fixed in the axis and facing the exit opening of the nozzle. The point of the cone is pointing face to the shot and thus opens it in the shape of an umbrella at 45°, necessitating to the shot an annular action area.
If it is used bare, without any adapter, this system makes it possible to treat pipes with an inner diameter ranging from 20 to 75 mm. By adding fixed collars and sleeves, it is possible to treat pipes with an inner diameter ranging from 75 to 125 mm. Equiped with a mobile and extensible carriage, it is possible to treat pipes with a diameter up to 300 mm.

Dynamic nozzles system
A disengaged rotary head is fitted out with two nozzles diametrically opposite so that their respective position creates a mechanical couple. The action of the air pressure coming out of the nozzles generates an opposite reaction which causes a backward movement of the nozzles and carries them in an opposite rotation. The compressed air, vector of the abrasive carriage, becomes also the power unit energy of the rotary head carrying the nozzles.
The shot is inscribed in a circular movement and perpendicular to the system axis which is set up on a mobile carriage and makes it possible to treat pipes with an inner diameter ranging from 170 to 900 mm.

Assembly and manoeuvre
These static or dynamic equipments can be assembled easily at the end of a shot hose, on all the pressure tanks.
The apparels are introduced and pushed, or pulled in the pipes, from one end to the other, adapting the moving speed in order to obtain the quality of the treatment desired.