what is the difference between an apron feeder and a conveyor
I. Definitions
An apron feeder is a reliable feeding method suitable for transporting bulk, abrasive, heavy-duty, and high-temperature materials. It is a more robust feeding solution than traditional belt feeders. Designed to deliver materials to downstream equipment at the required processing capacity, the materials are carried on multiple overlapping pans connected to heavy-duty tractor-track chains.
A conveyor is a mechanical device that continuously transports materials along a fixed route, typically for material handling from a loading point to an unloading point. Conveyors can transport materials horizontally, inclined, or vertically and can form spatial conveying routes, usually with fixed paths. They are classified into various types by operation, including belt conveyors, screw conveyors, bucket elevators, drum conveyors, chain plate conveyors, mesh belt conveyors, and chain conveyors, each with unique characteristics and applications.
II. Working Principles
Apron Feeder:
Composed of main shaft units, feeding pans, drive units, frames, support rollers, return rollers, and tail wheel tensioning devices, an apron feeder transports materials via chain-driven plate traction. The motor drives a speed reducer to reduce speed and increase torque, rotating the main sprocket to pull a closed chain and attached plates in a cyclic motion. The plates form a continuous load-bearing surface that receives materials (e.g., ore, coal) from the inlet, conveying them along horizontal or inclined frames (up to a 25° incline) to the discharge end, where materials are unloaded by gravity or baffles.
Conveyor (Take Belt Conveyor as an Example):
Structurally diverse by type, a belt conveyor is one of the best choices for bulk material transport, continuously moving materials from one location to another. It consists of a conveyor belt, drums, idlers, frames, tensioning devices, drive units, and protection switches. The motor drives the main drum, which uses friction to cycle the endless conveyor belt. Materials fall onto the belt from the inlet, supported by idlers to maintain a flat conveying surface, and move with the belt to the discharge end. Speed can be adjusted via a frequency converter, and combined with electronic scales for quantitative control, making it suitable for continuous transport of powdery and granular materials. Belt conveyors are widely used in mining, metallurgy, ports, cement, food, and chemical industries.
III. Structural Design Differences
Apron Feeder: Relatively compact, with special feeding methods (vibration, disc, screw) tailored to material characteristics and feeding precision requirements.
Conveyor: Diverse structures; for example, belt conveyors are simple with adjustable lengths, while bucket elevators are designed for vertical transport.
IV. Functional Focus
Apron Feeder: Primarily focuses on precisely controlling material supply speed and quantity, feeding materials uniformly and quantitatively into subsequent equipment to ensure stable operation in downstream processes.
Conveyor: Prioritizes long-distance, high-volume material transport between locations, with less emphasis on feeding precision.
V. Application Stages in Transportation
Apron Feeder: Core application at the starting end of the transportation process, such as feeding at the front of mineral primary crushing.
Conveyor: Used across all stages of the transportation process.
VI. Transportation Distance
Apron Feeder: Particularly suitable for short-distance transport of large, high-density materials.
Conveyor: Mostly used for long-distance transport in horizontal, inclined, or vertical directions.
VII. Transportation Methods
Apron Feeder: Capable of horizontal, inclined, and high-inclination (up to 25°) transport, but not vertical.
Conveyor: Capable of horizontal, inclined, and vertical transport (e.g., bucket elevators).
VIII. Applications
Apron Feeder: Mainly used to uniformly transport materials from storage bins to crushers, conveyors, or other machinery, ideal for short-distance transport of large, dense materials. Widely applied in mining, metallurgy, building materials, chemicals, and coal industries. It serves diverse feeding, unloading, and discharging purposes, such as crusher feeding, truck unloading, hopper discharging, and stockpile reclaiming.
Conveyor: Used for long-distance transport in horizontal, inclined, or vertical directions across industries like food, chemicals, pharmaceuticals, building materials, metallurgy, and coal. Its primary role is material transportation, with a narrower focus compared to apron feeders.
IX. Applicable Materials
Sticky/Wet Materials:
Apron Feeder: Handles sticky/wet materials well, thanks to vertical or negative-angle walls that prevent adhesion and blockages via unique angle designs.
Conveyor: Requires specific types (e.g., belt conveyors with anti-adhesion designs) and may not be suitable for all types (e.g., vibrating conveyors are prone to blockages).
Corrosive Materials:
Apron Feeder: Suitable for corrosive materials with proper material selection (e.g., stainless steel).
Conveyor: Feasible but requires type and material selection (not all conveyors are suitable).
Heavy-Duty/High-Impact Materials:
Apron Feeder: Designed for heavy loads and high impacts (e.g., ore, steel scraps).
Conveyor: Not all types are suitable (e.g., screw conveyors are vulnerable to wear and impact).
X. Conclusion
While apron feeders and conveyors may appear similar superficially, they differ significantly in working principles, structural designs, functional focuses, application stages, transport distances, methods, applications, and material compatibility. Understanding these distinctions is crucial for selecting the right equipment to meet specific industrial needs.
