Principle Of The Injector - Gema OptiFlow IG06-BN Operating Instructions And Spare Parts List

Principle of the injector

OptiFlow IG06-BN
Rev. 00 05/19
When air flows through a nozzle into a cavity with an attached outlet in
the continuation of the airflow, a vacuum will be created in the cavity (see
figure below). This effect is used now for aspirating powder through a
suction opening – a powder/air mixture will be created.
fig. 3
1 Conveying air
2 Supplementary air
3 Insert sleeve
4 Powder/air mixture
5 Vacuum
This powder/air mixture is fed through to the powder hose to the gun. The
concentration of the powder/air mixture and therefore the powder output
amount, depends on the conveying and supplementary air volume, the
powder quality, the powder hose length, the powder hose diameter, the
number of coils in the hose, the height difference between the powder
gun and the injector and the nozzle type. Place great importance on the
insert sleeve condition, because wear causes the powder output to
reduce drastically.
Experience with pneumatic material handling technology shows that
pneumatic transport of fine solid matter (powder) in the form of tubing
(hose), the transporting medium requires a certain volume of air per unit
of time. If a hose diameter of 11 mm is used, the value is approx. 4 m³/h.
In order to reduce the powder output, the vacuum in the cavity of the
injector must be lowered by reducing the conveying air pressure. By
reducing the conveying air pressure, the air volume in the powder hose
sinks to below the optimum value of 4 m³/h, the powder transport
becomes irregular and the so-called "pumping" takes place. In order to
prevent this from happening, supplementary air is added until the total air
volume in the powder hose is 4-5 m³/h once more. This takes place fully
automatically by the Gema control unit.
6 Suction tube
7 fluidized powder
8 Powder container
9 Nozzle
Product description  11