Pneumatic conveying vs. mechanical conveying: Breaking down the differences

OVERVIEW OF PNEUMATIC SYSTEMS

Pneumatic systems are the ideal solution when it comes to transferring dry bulk materials. Using an enclosed pipeline, these materials are moved using industrial air systems such as positive pressure systems, vacuum systems, dilute phase systems, or dense phase systems. Air or inert gas is used to move the materials along through the system. However, the means of producing the airflow and its direction differ from system to system.

Positive pressure system: To convey a product from point A to point B generally requires a positive pressure blower package, rotary airlock, a cyclone receiver (sometimes with an airlock valve) and the tubing system with elbows, sight glasses, and couplings. The exhaust air from the cyclone receiver will need to vent to a secondary filter, scrubber, or into the atmosphere. One of the features of a positive pressure system is that you can add pickup points and deliver to multiple destinations. Simply add inline diverter valves to the conveying line and pick any one of several destinations. There are various methods of discharging to multiple destinations.

Vacuum system: Rather than pushing with air like the positive pressure system does, the vacuum system pulls materials through the pipeline instead. This method is considered a more sanitary means of moving bulk materials.

Dilute phase system: This industrial air system is used for lighter materials (such as powders) using a blower to suspend them in the airstream. This system uses pressurized air that moves materials along at a high velocity.

Dense phase system: This industrial air system is used to convey heavier materials that aren’t in a powdered form, such as plastic pellets. Since the materials aren’t suspended in air, this conveying system pushes the product through in waves and operates at a higher pressure and lower conveying velocity than dilute phase systems.

OVERVIEW OF MECHANICAL CONVEYING SYSTEMS

Mechanical conveying systems are used to transport heavy bulk materials. Whereas pneumatic conveying systems are generally used for powders and pelletized products, mechanical conveying systems are best suited for crushed rock, gravel, and other materials that are large in size, abrasive, and can’t be moved via airstream. It’s also the conveying system of choice for products that are high in moisture, oil content, or fat.

The control system design of mechanical conveying uses traditional machinery as opposed to air. Common parts used for the conveying process include belts, chains, driver motors, buckets, rollers, and sprockets. There are many different types of mechanical conveying systems.

Belt conveyors: This is the ideal system when moving large quantities of material over long distances. It uses a wide belt on top of rollers, which makes for speedy transport.

Bucket elevators: This method of conveying uses buckets to elevate products to high elevations inside a factory or plant.

Screw conveyors: Used to transport wet materials horizontally over a short distance (typically less than 24 feet).

Drag chain conveyors: Best for transporting dry products over long distances, drag chain conveyors use a chain and paddle design.

Vibrating feeders: Using vibrating trays that offer constant motion, vibrating feeders are best for products that are at risk of clumping or sticking if allowed to remain idle.

THE ADVANTAGES OF PNEUMATIC SYSTEMS FOR CONVEYING MATERIALS

There are many advantages when it comes to pneumatic conveying systems as they relate to an application. The major ones include

• The ability to route the system around existing equipment inside your plant or facility. Pneumatic conveying systems can be built to run both horizontally and vertically, making it one of the most versatile solutions to moving bulk products.
• The benefit of protecting the product from outside contaminants; since the product is enclosed in the pneumatic conveying system’s ducts and piping, there’s no chance of it being compromised.
• Compared to mechanical conveying systems, pneumatic conveying systems are more cost-effective and are far easier to maintain due to the lack of moving parts; they also take up less floor space.
• The convenience of having multiple points in the system where products can be discharged or introduced.

THE ADVANTAGES OF MECHANICAL CONVEYING SYSTEMS

Comparatively, mechanical conveying systems have their own distinct advantages. The major ones include

• Can be built using pre-assembled modular systems, which makes for quick construction of the conveying system
• Can transport materials that are high in moisture, oil, or fat without slowing or clogging
• Can transport materials that are heavy and/or abrasive, such as gravel or rock
• Mechanical conveying systems often require less overall horsepower to run

CONTACT KICE INDUSTRIES TODAY TO DISCUSS HOW PNEUMATIC SYSTEMS CAN BENEFIT YOUR OPERATION

As we’ve outlined here, you have several options when it comes to conveying materials. The best way to see which method of pneumatic conveying is best for you is by getting in touch with the experienced team at Kice Industries. Our designers and engineers will evaluate your operation and then consult with you as to which pneumatic systems are right for you. The advantage of using industrial air systems is that they can be utilized for several different applications across multiple industries.

You can either contact us by phone at (316) 744-7151 or email us at sales@kice.com.