Removal of plastics from digested food waste using STRAINPRESS® Sludgecleaners

Figure 1: STRAINPRESS® Sludgecleaner on Gantry between digester and first digestate storage tank
Figure 1: STRAINPRESS® Sludgecleaner on Gantry between digester and first digestate storage tank
Figure 2: Pressed screenings from the STRAINPRESS®
Figure 2: Pressed screenings from the STRAINPRESS®

A case study of Huber Technology UK, Chippenham/Wiltshire:

In order to meet the Quality protocol PAS 110 for use of digestate as a fertiliser the plastics content must be reduced. How the plastics are removed will depend on the upstream process however we at HUBER have successfully trialled and installed our STRAINPRESS® coarse material separator for plastics removal at a number of sites.

At Andigestion in Devon we initially supplied a STRAINPRESS® with a 5mm screen immediately after the digester and this met the original PAS 110 however more plastics were required to be removed by the local farmers and a second STRAINPRESS® with a 3mm mesh has now been installed after the first storage tank. 

The STRAINPRESS® Sludgecleaner is totally enclosed and the liquid phase is under pressure allowing the first unit to be installed between the digester and the first digestate storage tank. In this instance we used the constant head in the digester to pressurise the machine.

The second unit was installed between the first digestate storage tank and the second and was pump fed.
The oversize plastics falls out of the STRAINPRESS® into a skip mounted below the machine. Cleaning of the STRAINPRESS® is by mechanical means and no additional water, chemicals or flocculants are required.

The resultant screenings from the 5mm mesh showed a good capture ratio, with the screenings at about 50% dry solids. The amount of shredded plastic removed can clearly be seen in figure 2.

With over 316 STRAINPRESS®’s installed in the UK alone, many for the same client, this is a well proven and reliable piece of equipment.
 

For more information please contact:
  Tony Clutten                    
  Process Sales Manager            
  Huber Technology                
  Email tchuber.couk                 
  Tel. +44 12 49 765050      
  Mobile +44 725224521