Q2. Apron feeder design

A plane flow hopper is proposed for delivering gold ore from a course ore stockpile. This hopper is to provide feed to a processing plant at a controlled throughput of 2000 t/hr using a belt feeder inclined at 8⁰. The bin opening and hopper half angle chart is shown in Figure 2.

The following parameters are known from flow property test and design constraints:

• Distance between top of hopper and belt feeder: 4m

• The vertical surcharge pressure (Ps) at the top of the hopper is 140 kPa

• Maximum Belt Feeder Speed: 0.35 m/s

• Bulk Density: 1850 kg/m3

• Internal Friction Angle: δ=52°

• Hopper Liner Material: Arcoplate

• Optimum Hopper Gate Height to Width: 0.7

• Vertical End Walls

• Volumetric Efficiency of Feeder: 75%

• The projected ‘length’ to ‘front gate width’ aspect ratio of the outlet should be 3.5:1

• Particle Top Size: 40 mm

• Bulk Material is very moderately compressible.

Tasks:

1. Provide Basic Hopper Geometry for Mass Flow to the feeder

2. Develop Transition Geometry to ensure optimal draw down in the mass flow hopper

3. Calculate the Load Estimate required for the belt feeder