The first stage of the hopper design process commences with establishing the form of flow regime that should be generated when discharging. (See separate notes on Flow Regimes in Hoppers).
The basic choices are:
1.Mass Flow(see notes on benefits and drawbacks of mass flow)
For products that deteriorate in some way over time and are to be held in hoppers that may be re- filled before fully emptying.
2.Expanded Flow
For products with poor flow properties that either do not deteriorate in extended storage or the non-mass flow contents will be discharged before the hopper is re-filled.
3.Funnel Flow For free flowing products that do not deteriorate during extended storage time.
The second stage is to choose a geometric form for the storage container, usually either circular, with conical hopper section or rectangular, with pyramid or slot outlet. The outlet region may be transformed to a chisel shape to exploit the flow benefits of plane flow and slot outlets. Eccentric shapes and multiple outlets are normally best avoided.
This choice tends to depend on site circumstances and structural economics. Cylinders and cones are commonly chosen for simplicity of design and their capacity to contain pressures, whereas rectangular members nest well and hold maximum capacity for a given floor area, but require stiffening on their flat surfaces.
The third stage is to determine walls angles and the required outlet size, as the attached design chart, Table 1. This choice may be influenced by the inclusion of a feeder to control the rate of discharge, enhance the storage capacity or flow rate and/or aid the reliable discharge of the material.
Hopper Design Process
Hopper Design Process
The first stage of the hopper design process commences with establishing the form of flow regime that should be generated when discharging. (See separate notes on Flow Regimes in Hoppers).
The basic choices are:
1.Mass Flow(see notes on benefits and drawbacks of mass flow)
For products that deteriorate in some way over time and are to be held in hoppers that may be re- filled before fully emptying.
2.Expanded Flow
For products with poor flow properties that either do not deteriorate in extended storage or the non-mass flow contents will be discharged before the hopper is re-filled.
3.Funnel Flow For free flowing products that do not deteriorate during extended storage time.
The second stage is to choose a geometric form for the storage container, usually either circular, with conical hopper section or rectangular, with pyramid or slot outlet. The outlet region may be transformed to a chisel shape to exploit the flow benefits of plane flow and slot outlets. Eccentric shapes and multiple outlets are normally best avoided.
This choice tends to depend on site circumstances and structural economics. Cylinders and cones are commonly chosen for simplicity of design and their capacity to contain pressures, whereas rectangular members nest well and hold maximum capacity for a given floor area, but require stiffening on their flat surfaces.
The third stage is to determine walls angles and the required outlet size, as the attached design chart, Table 1. This choice may be influenced by the inclusion of a feeder to control the rate of discharge, enhance the storage capacity or flow rate and/or aid the reliable discharge of the material.
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