Abstract:
Firewood is widely used as a Biomass energy source for various purposes in the world till the
invention of liquid petroleum gas (LPG). Even after LPG cylinders arrive, fire wood is still
being used in household cooking, heating and specially used in small scale industries such as
bakeries and tea factories. Firewood has to be cut and split into pieces for proper and efficient
combustion because outside surface of the firewood should have rough edges or splinters in
order to catch fire easily and to take firewood into the ideal moisture content for combustion
quickly. Splitting is done by both manual and mechanical methods. Splitting of wooden logs
by the use of axe is a tedious and time-consuming method. Hydraulic assisted machines are
designed to make splitting task easy. But these machines cost high initial investment and require frequent maintenance. This leads to the design and fabrication of low-cost model of a log
splitting machine which is affordable even in the small-scale industries in rural areas. In this
study machine was designed with direction controllable electric motor (2400 rpm,735 W and
3-Phase) which is used to rotate a square threaded power transmitting screw. Square threaded
screw is coupled to a gear box (worm and wheel type, 90 degree angular, gear ratio 10:1) to
achieve required torque of 25 Nm. Pushing mechanism which is activated through the rotating
screw provides required force to split wooden logs. Wooden logs are split by pushing them
against a cross type wedge. Manual reversing mechanism is used assisted by two limit switches
to identify the position of push plate. Final log splitter is capable of generating 7 kN of force
to push the log through the wedge. Also, it is capable with handling average 120 logs/hr with a
diameter of 1ft and a length of 1 ft.
