At UniTrak, we supply bulk material conveyors for applications where the required equipment capacity is 3,000 cubic feet per hour or less. There are many technology types available when it comes to choosing a conveyor for these types of applications. A common question from customers is which technology type is the most efficient. The answer to this question depends in large part upon what one means by “efficiency”.
What is meant by conveyor “efficiency”?
Efficiency can have different meanings depending upon context. For example, when efficiency is considered from the perspective of equipment footprint and space utilization, tubular drag conveyors are among the most efficient. From an alternative perspective, when one means by “efficiency” the ratio of equipment horsepower (energy requirements) to capacity, then bucket conveyors are among the most efficient. Thus, the answer to the question of which conveyor type is the most efficient depends on what is meant by “efficiency”.
How do different conveyor technologies compare in terms of “efficiency”?
Given the above, there is no straightforward answer to this question. However, we summarize below some of the relative efficiencies and inefficiencies of commonly used conveyor technologies:
Flexible screw conveyors. Flexible screw conveyors have the advantages of simple operation, relatively low cost, and smaller space requirements. These conveyors work well for handling a wide range of materials. Key inefficiencies of flexible screw conveyors are their poor ratio of energy consumption to equipment capacity, and their propensity to degrade or damage friable products, causing throughput losses and scrap.
Aeromechanical conveyors. Working on the principle of a fluidized air stream, aeromechanical conveyors work well for handling many bulk powders. These conveyors are quite efficient in terms of their ratio of energy consumption to capacity. Another advantage of aeromechanicals is that, by moving product on a fluidized air stream, this may aid product flow in downstream processes. The major disadvantage of aeromechanical conveyors is their moderate to high maintenance requirements and the need to regularly adjust and inspect the rope assembly.
Tubular drag conveyors. Tubular drag conveyors have lower energy requirements than flexible screw conveyors. Another efficiency gain with tubular drag conveyors is their lower rate of wear and decreased maintenance requirements, resulting in cost savings that more than offset the higher price normally associated with these types of conveyors.
Bucket conveyors. These conveyors can move large amounts of material effectively and efficiently. Depending upon the equipment design, bucket conveyors may or may not be kind to the product they are handling: equipment designs, such as that found on TipTrak™ conveyors from UniTrak, gently handle product and eliminate throughput losses attributable to product damage. Compared to tubular drag, flexible screw, and aeromechanical conveyors, bucket conveyors do have a larger equipment footprint and require more floor space. Bucket conveyors are also quite energy efficient – for example, TipTrak™ bucket conveyors from UniTrak are equipped with fractional horsepower motors for many applications.
Belt conveyors. Belt conveyor are capable of moving large amounts of materials over long distances. However, a major inefficiency of these conveyors is that they consume more floor space than other conveying technologies.
Pneumatic conveyors. Dense and dilute phase pneumatic conveyor technologies each have their advantages and disadvantages. Major inefficiencies with both types is their higher ratio of horsepower to capacity, meaning they are less energy efficient than mechanical conveyors. In addition, pneumatic conveyors have a higher rate of wear and increased maintenance requirements. Pneumatic conveyors also require larger dust collection systems than mechanical conveyors, as the material must be separated from the air used within the system.
In summary, while each conveying technology has its strengths and weaknesses, the type of technology chosen should always be based upon a comprehensive and thorough review of the application requirements. Depending upon the application and the final equipment choice, users may have to trade-off some efficiency for effectiveness to have their requirements fully addressed.
UniTrak Corporation Limited supplies flexible screw, aeromechanical, bucket, and belt conveyors to customers the world over. We have an extensive product lineup and over 45 years’ experience in solving our customers’ toughest bulk material handling challenges. To find out more about we can address your needs and requirements, please contact our sales department.