If a company processes more than 1000m3 of wood or wood-based products a year, then a permit is needed for wood machining process under guidance note PGN-602. This guidance note covers the extraction and storage of wood-waste in the form of shavings and dust, it also covers the handling and disposal of off-cuts.

As well as needing a permit from Environmental Health, manufacturers must also comply with ATEX and DSEAR  (Dangerous Substances and Explosive Atmospheres Regulations 2002).

A 7m diameter 350m3 storage silo

Ranheat Engineering, as well as being leading manufacturers in industrial wood-fired boilers and heaters and biomass-fuelled boilers and heaters, also manufacture and install a wide range of types and sizes of silos and storage bunkers for industrial wood-waste. Most of the systems involve a wood-burner but not all do. 

Under certain circumstances ,wood-waste will be blown into a trailer. But what happens when the trailer is taken away to be emptied? The answer is a buffer store in the form of a silo so that production in the factory can continue whilst the trailer is away being emptied.  

Conical bottomed round storage silos require only a single discharge motor driving an agitator arm at the base of the cone. With this silo arrangement the silo can be fully emptied. Some manufacturers provide a square silo with a round discharge mechanism – which means the silo can never be emptied.

Rectangular open top ‘bunker’ silo mounted internally loaded with wood-chips

The Ranheat silos are fitted with accredited explosion panels fitted to the roof. Ranheat use a detailed computer model to calculate the number of panels needed for a given storage volume. The panels are accredited in batches with a % being destruction tested.

Ranheat also make a range of storage silos than are for use with wood-chips that can be loaded with a bucket loader. These bunker silos have a hydraulic scraper mechanism that moves across the bottom of the silo to a discharge point. They can also be used externally with a canvas top if loaded with a conveyor.

A flat-botttomed silo with augers

Other discharge mechanisms are available with flat bottom silos containing a series of augers that move the material to a central discharge point. 

The augers are driven by two small electric motors with chain drives between the augers. Just another example of a mechanism that can fully empty a rectangular silo.