Pneumatic Convey Burnt Lime

Posted in: , on 14. Feb. 2003 - 15:46

A customer wants to convey Burnt Lime Pneumatically. Material properties are the following:

Material : Burnt Lime

Constituents : 80-85% CaO

02-05% CaC03

Remainder - Inerts and heavy metals

Temperature : 80 deg Celcius

Density : 1140 kg/m3

Rate : 15 tons / hr

Particle Size : 10 to 20 mm with fines

Distance : unknown on this stage

Before we go into the detail, can it be done and are there any special steps to be taken with this material?

Hugo Lombaard



South Africa

Hugo Lombaard [email][/email] Johannesburg South Africa

Re: Pneumatic Convey Burnt Lime

Posted on 16. Feb. 2003 - 05:48

Dear Mr. Lombaard,

Burnt lime, especially soft burnt lime is very fragile. This means, be carefully with high velocities inside of conveying pipe. On the other hand, dense phase or plug conveying is very difficult because of the fines and the soft material.

I would recommend to use stepped pipes according to the length of transport and pressure drop. Solids/air ratio not more then 10 - 15 kg/kg, depending on pipe length and pressure drop.

Use very long radius bends only.

Use dried air. If you have to storage burnt lime in a silo, avoid circulation of air or use dried air inside of silo. otherwise burnt lime can react with humidity in the air.

If you have further questions don´t hesitate to contact me.


Klaus Schneider

Dennis Hauch - Freeport, TX, USA
(not verified)

Burnt Lime

Posted on 26. Feb. 2003 - 12:37


Key to the successful pneumatic conveyance of the burnt lime material that you described is the particle size distribution (PSD). This is especially true if the material is easily degraded as it is handled. Materials having a wide PSD will often require a bypass type of system if they are to be conveyed pneumatically.

Difficult to convey materials such as burnt lime may be better handled with a drag tube conveyor, you might consider this.


Dennis Hauch