Efficient Wood Chip Drying

Heat Recovery System for Beltdryer

bandtrockner

Aside from costs of transport and raw material, drying costs are amongst the biggest cost factors in Pellet Production.

While the first two factors are mainly predetermined by the environmental conditions of the respective Pellet Producer, the costs of drying offer considerable savings potential. With the Beltdryers made by Muehlboeck in Eberschwang, with their integrated Heat Recovery System, this potential be tapped into.

‘Heating costs account for about two-thirds of the drying expenditure. This according to profitability analyses based on customer information’ explains Sales Director Richard Muehlboeck. It is here that the company provides savings of up to 50%, through its Heat Recovery System for Beltdryers.

Proven system with new technology
The basis of the new drying system constitutes a beltdryer with all of the well-known technical structures. ‘The disadvantages of this otherwise proven drying system were put aside by us, by having part of the dryer operate on the principle of air circulation, in order to efficiently use the airstream. A system of air routing that we also apply in our lumber dryers’, explains Muehlboeck. Furthermore the dryer is equipped with a large Heat Recovery unit, through which all the energy that is being held in the exhaust air, is recovered. ‘Part of the dryer therefore draws the necessary thermal energy exclusively from the Heat Recovery’ Muehlboeck points out.

Retrofitting at existing installations
For clients with limited heat supply, who at the same time would like to compensate for the lower output of the dryer in the winter months, retrofitting their existing installation with a Heat Recovery System of Type 1003 provides a good opportunity. Depending on the customer’s requirements, the existing belt surface would be enlarged or only the existing dryer converted, while a major part of the existing beltdryer would still be used, as the company informs us.

Dust is not an issue
According to dust measurements, conducted by a certified German test station on a dryer of Type 1003, values of under 3 mg/Nm3 have been achieved. ‘This is due to the fact that we guide the air in the post-drying zone at the end of the beltdryer, in a closed system over the Heat Recovery, back into the drying zone. In the pre-drying zone, such as with wet material, we naturally have low dust emissions’ explains Managing Director Kurt Muehlboeck concluding.

Holzkurier 37/2015