Bagasse received from sugar mills contains approximately 30-35% pith and about 50% total moisture. Since pith lacks fiber value, it must be removed to make bagasse fiber suitable for the pulp mill. The first step in this process is removing the pith using hammering action in the depither.

Pin Feeder: Bagasse is transported by a belt conveyor to the pin feeder, which regulates the flow of raw material into the depither. The pin feeder comprises two rollers rotating against each other, equipped with pins that distribute the raw material in a controlled flow to the depither. It is powered by a variable speed motor through a reduction gearbox. After passing through the pin feeder, the loosened bagasse falls into the depither.

Dry Depither: The depither is designed to separate dust from bagasse. Bagasse is fed through an inlet spout or chute at a specific rate to the top of the rotor assembly, where hammers rotate clockwise (when viewed from the drive end, i.e., from the top) at a predetermined speed.

As the bagasse falls between the rotor hammers and the screen, it is successively battered by each group of hammers. The pith and dust are then forced through the screen by centrifugal force and discharged through a dust chute to a conveyor, which transports the dust either to a boiler for burning or for disposal. The fiber is discharged through a fiber chute and then taken to a belt conveyor for washing.