Biomechanics Sustainability

a closer look at the heating system

By Jim Malloy & Craig Emerson

There are two sides to a burner's operation: the flame side and the liquid side.
A fuel burner's liquid side consists of a whole chain of interconnected parts: the tank, fuel line, filter, fuel pump, nozzle and burner.
Starting at the tank, for blends higher than 20% biodiesel only steel, mild steel, stainless steel, aluminum, fluorinated polyethylene, fluorinated polypropylene and fiberglass vessels are recommended.
Previously used petroleum tanks should be inspected for several potential problems, such as sludge, which can plug up the filter. The removal of the sludge can also make weak spots in the tank susceptible to leaking. Biodiesel has great solvent properties. In older tanks, I believe starting with a lower blend of biodiesel (B20) helps clean the liquid side of the fuel delivery system. Then change your fuel filter before stepping up to B100, and then change your fuel filter again.
In older tanks, starting with B20 before moving up to B100 will reduce chances of plugging filters and nozzles.  
We have successfully used a 40-year-old oil tank, starting at a B5 we have gradually converted it to a B100 tank.  
If you are starting with a new tank, there is no reason not to start with B100.  The B100 tank should be kept in a space that is dry, dark and kept at 52 degrees Farenheit or warmer.
From the tank the biodiesel travels towards the burner through the fuel line. R.I. law requires copper coated lines as the only fuel line, but people do use black steel also.
Next the fuel travels through a filter to the fuel pump.
The pump should be upgraded for biodiesel compatibility. For B20, Webster and Suntech are a couple of pump brands we use. For B100, I recommend Webster pumps.
In other pumps, the gaskets are usually what will fail. Unfortunately, it is costlier and more complicated to replace the gasket than the entire pump.  
Pumps should next be adjusted from 100psi to 175psi when burning B100. As you do that, your nozzle size should be downsized by 33%.
If the psi isn't raised and the nozzle downsized, the 'safety' shut off in the burner will be set off and the burner will need to be reset over, and over, and over....
The flame side of the burner has one significant change. The emissions are cleaner.