There are several types of Feeders. Choosing the right one for your application should be based on the characteristics of the material to be handled and the required capacity.
Selecting a Feeder for a particular situation is not always simple, however, especially if more than one satisfactory solution appears possible.
Some of the criteria for choosing the proper Feeder includes:
1. Gradation and lump size
First, consider the gradation of the material the Feeder will handle. Be sure to include the largest lump size (even if it is less than 1% of the total gradation) as well as the smallest particle size in this analysis.
2. Feed rate
Next, determine the capacity of the Feeder, taking into account the design maximum, normal and minimum capacities. Determine if the feed rate is going to be fixed or variable.
3. Type of material and its characteristics
Consider the material the Feeder will process. When sizing a Feeder, it is important to know the following information about the material:
- hardness
- density
- abrasiveness
- shape
- angle of repose
You'll also want to consider if the material is free-flowing, sticky, wet or dry.
4. Temperature
Consider the material temperature and the ambient temperature range at the operation site.
5. Is scalping desired?
If the material is to be scalped by the Feeder, consider the desired size of the material and what percent is to pass the opening. Determine if there is one scalping size or multiple sizes.
6. Type of operating duty
Consider how many hours and days per week the Feeder will be operating.
7. Portable or stationary
Determine if the Feeder is going to be installed on a portable or stationary plant, and know if weight and size of the Feeder will be a factor.
8. Space available and site amenities
Consider the space that is available for the Feeder. If this is an underground mine, know if there is a limit to the size and weight that can be transported in the mine shaft or tunnel. Also consider how much space is available for maintenance.
Site amentities are another important aspect to consider when sizing a Feeder. Be sure to consider the type of power available at the site (line or generator), and if you prefer a hydraulic or electric drive. Also take into account the elevation and climate of the site.
9. Type of loading
Consider how the Feeder will be loaded (haul truck, wheel loader, conveyor, crusher, etc.), and know the size of this piece of equipment.
10. Downstream equipment type and size
Consider the type of equipment the Feeder is charging (truck, train, conveyor, crusher, screen or scalper). Also consider the type and size of crusher or downstream equipment the Feeder is planned to feed.
Types of Feeders
The types of Feeders include:
- Apron Feeders
- Belt Feeder
- Reciprocating/Plate Feeders
- Vibrating Grizzly Feeders
- Wobbler Feeders
Apron Feeders
The Apron Feeder is higher on capital investment and higher on investment returns. It is the most robust Feeder and is commonly used in the mining industry under 24/7 operation with years between maintenance periods.
Apron Feeders are used for:
- small and large capacities
- extreme impact loading
- uniform feed rates
- many types of materials, such as minerals, aggregates and recyclables
- long service life with low maintenance
- custom tailored applications and installations
- very hard, abrasive and tough, and for lumps of larger dimensions and that which are beyond the scope of other Feeders
Belt Feeders
Belt Feeders are generally used for fine material applications. These are flat belt conveyors supported by closely spaced idlers and driven at the head pulley.
Belt Feeders are used for:
- smaller sized materials
- smaller hoppers
- secondary or tertiary applications
Reciprocating/Plate Feeders
These Feeders are a reciprocating tray-type feeder. The reciprocating motion is produced mechanically by a crank or eccentric and connecting rod, or hydraulically operated by a hydraulic cylinder. The Feeder discharge occurs during the back stroke of the plate — no material is discharged in the forward stroke.
Plate Feeders are generally installed under a bin and are used for:
- small and large capacities
- cyclic feed rates
- long service life with low maintenance
- custom tailored applications of installations
Vibrating Grizzly Feeders
Vibrating Grizzly Feeders are smaller in size than Apron Feeders and are used where pre-sorting is required before a crusher. Material is conveyed along the pan of the Feeder as a result of the vibrating motion imparted to the particles. This vibration pre-sorts the material, passing the fines to the bottom. The fines can then be pre-screened before a crusher, thus reducing the required capacity and wear.
Vibratory Feeders are used for:
- small and medium capacitites
- close to uniform feed rates
- many types of materials
- some custom tailored applications of installations
These Feeders are lower on capital investment and lower on investment returns.
Wobbler Feeders
Material is conveyed along the Wobbler Feeder as a result of the rotating motion of the elliptical bars. This motion scrubs and pre-sorts the material, passing the fines to the bottom. The fines can then be pre-screened before a crusher, thus reducing the required capacity and wear. The Wobbler Feeder is high on capital investment and medium on investment returns.
Wobbler Feeders are used for:
- small and medium capacities
- where pre-sorting is required before a crusher
- uniform feed rates (dependent of homogenous feed gradation)
- generally used for sticky types of materials to scrub the fines off
Wobbler Feeders are not used for any round or slick material such as gravel or coal.
Knowing the criteria for selecting a Feeder, as well as the differences in Feeder types, can help you determine the right one for your application. If you need further assistance choosing a Feeder, contact us today!
