Conveying and Receiver Vessels

In chemical processing it is often required to convey a range of different powders and granules with the same vacuum conveyor. For example, in the paint industry various dyes and pigments are to be transferred. Therefore the design must be simple and should allow easy dismantling and cleaning. 

Dependency of transfer throughput from bulk density 

For approximately 10 m conveying distance. Attention Each bulk material may show, different behaviour.  

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In a similar variety conveying and receiver vessels are applied. Such are... 

Figure 17.10 Conveying and receiver vessels in modular, single-body and pressure-rated design. (Volkmann Vakuum Technik GmbH.)...

Pressure build-up Provide adequate venting and dust filtration on downstream of receiving vessel vent mill (risk of com-, Where liquefied gas (nitrogen or CO9 ) is used ponent failure, ensure adequate vent sizing and limit particularly in gas liquefied gas feed-rate to mill conveying systems). Internal pressure may also force product out of the mill. CCPS G-11 CCPS G-22 CCPS G-23 CCPS G-29... 

Whilst entering the vacuum conveyor, the conveyed material is decelerated by the increased diameter of the receiver vessel and therefore the main bulk material is collected at the bottom section of the conveyor. 

The principle of discontinuous conveying allows a simple design but reaches boundaries when it comes to conveying heights of more than 30 m and distances of 100 m. With the combination of two receiver vessels and if the pneumatic control is switched to the twin mode a continuous vacuum in the conveying line is maintained (Figure 17.14). Alternatively a rotary valve can be used. 

Pneumatic conveying of a mixture of coals at exit velocities of around 20ms , (which is at the low end of those found in industrial practice) resulted in considerable product degradation. The size distribution of the material arriving at the receiving vessel was shown to vary during conveying. Both these factors could lead to inefficient boiler operation and unacceptable levels of particulate emissions. 

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