Heat recovery from wet wood waste

Patent · Tue Nov 25 04:00:00 EST 1980

OSTI ID:6794140

Spurrell, R M

Overall heat recovery from wet wood waste, particularly sawmill generated hog fuel, is improved by a process for predrying the fuel. A wet oversize fraction of the fuel is combusted in a fluid bed reactor providing heat for drying the remaining smaller sized fraction of the waste pile to about 10-30% moisture by weight. The gaseous products of the fluid bed burning are contacted with the fuel fraction in, preferably, a rotary dryer. The dried fuel is then screened into coarse and fine fractions. The coarse fraction is fed onto a grate of a wood waste boiler. The fines fraction is injected into the boiler combustion in an air suspension. The amount of fuel fed to the fluid bed reactor is 10-25% of the total fuel flow, depending upon the moistu content of the fuel. The gases fed to the rotary dryer are less than about 1,200/sup 0/F., to minimize ''blue haze,'' by combining with minimum outside air.

• Assignee: Weyerhaeuser Co
• Patent Number(s): US 4235174
• OSTI ID: 6794140
• Country of Publication: United States
• Language: English

Related Subjects

09 BIOMASS FUELS
090400* -- Solid Waste & Wood Fuels-- (-1989)
42 ENGINEERING
421000 -- Engineering-- Combustion Systems
BOILERS
CHEMICAL REACTIONS
COMBUSTION
DRYING
ENERGY RECOVERY
FLUIDIZED-BED COMBUSTION
HEAT RECOVERY
OXIDATION
RECOVERY
SOLID WASTES
THERMOCHEMICAL PROCESSES
WASTES
WOOD WASTES