biomass chip-does size matter..

[organicdave]

Hello..well we have a Binder 93k biomass central heating boiler fed by lovely,clean seasoned softwood logs chipped by a Heizohack 4-300 which is powered by a Renault 106-54.pretty much a total success story over the last 18 months or so with everything working beautifully with the annoying exception of the boiler supplier engineers moaning that the resulting chip is too small and contains too many fines whenever they visit for maintenance. Our system designer and fellow Binder and Heizohack operator friends say this is not a problem and that as our boiler is working perfectly well then why worry...so who is right?? has anyone else had a similar experience??

[renewablejohn]

I also have a heizohack chipper . What size screen are you running. I require a lot of fines for briquette manufacture so run a G30 screen and turn the feed in speed as slow as possible. If you want big chip than I would suggest a G50 screen and fast in feed but the resultant chip may well have less fines but will have a bigger tendency to bridge. I would suggest if your happy with the performance of your stove than why reinvent the wheel.

[organicdave]

thanks for your reply John,i should have mentioned the screen size is G50 in our Heizohack,i certainly agree you point of 'if it aint broke dont fix it'-my view entirely,the radiators are on,the water is hot and the Grundfos pumps are whirring away nicely-methinks the boiler suppliers are just covering themselves by insulting our chip!

[renewablejohn]

organicdave

 

Check what spec your Binder requires most chip boiler manufacturers specify G30 spec so your chipper in theory should be producing G50 spec which should be larger than required. If you have that many fines what speed are you running your heizohack at. I was advised 850rpm but I then looked in the manual and it advised maximum 750rpm.

[organicdave]

thanks for that john,well we have had the Binder re-commissioned and tweaked to accept G30-the original commissioning was set at G50,ie the same as the heizohack sieve.Having now sent a sample of the chip to the Binder suppliers,they are now satisfied that the chip,including fines,is now acceptable for the newly tweaked boiler..at last! all is well that ends well!