Dust

Fans for solids: granules, dust, fibers

Dust

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Fans for dust-containing gases must be designed in such a way that as few deposits as possible can form on the impellers and in the housing. Deposits on the impeller quickly lead to imbalance and bearing damage.

Impeller types:
For dust applications, the impeller vanes (Q-types) are designed in such a way that deposits at the blade rear side are avoided at higher surface speeds to the detriment of efficiency.

The housing must provide a possibility for easy cleaning. This is often achieved by a cleaning door on the housing. Also the area of ​​the inflow and outflow (flexible transitions) must be easy to clean and should contain as little wasted space as possible. Depending on the application, spray nozzles for impeller and housing cleaning are also integrated.

Dust and granules can be highly abrasive. The exposed surfaces must be protected from this stress. Reinforcements in the inflow or replaceable wear plates in the housing may be required depending on the gas.

Dust generates a stronger static charge than pure gases. Built-up static electricity must be dissipated safely. Dust can be a serious, often underestimated risk of ignition, both as a cloud and through deposit layers.

Special materials and coatings such as ceramics, application welding, etc. are used after detailed clarification of the operating conditions. Special seals, e.g. SP seals with an air barrier, make it impossible for dust to penetrate the drive shafts.

Recommended for dusty gases is the monitoring of the fan vibrations, since it is easier to detect deposits inside.