A pneumatic conveyor is a common piece of mechanical handling equipment that uses pressurized air to move materials from one location to another. The terms "air conveyor" and "pneumatic conveyor" are used interchangeably; pneumatic conveying involves a series of tubes or conveyance channels attached to air compressors, vacuum pumps or both for the movement of products. Pressure conveyors and vacuum conveyors push or pull objects through enclosed conveyance channels without the risk of scattering them accidentally.
Pneumatic conveyors have many uses and benefits. One of the under-utilized benefits of using pneumatic conveyors are the health benefits that they bring. In fact, pneumatic conveyors can save a factory (or any other business) much expense and trouble by preventing human error and safety risks. All pneumatic conveyor suppliers should consider offering pneumatic conveyors to prevent health risks.
The Prevention of Falls
Pneumatic conveyors can help reduce the fall risk of employees. A pneumatic conveyor can automatically move products or materials from one level to another, preventing the need for employees to use ladders or other dangerous lifts. When a conveyor moves the material, the employees are free to stay on the ground and keep safe. This could potentially save a factory thousands of dollars each year paid in injury coverage and protection.
The Prevention of Back Injuries
Carrying heavy loads can also cause health risks to employees. According to OSHA, it can take about 10 days for an employee to recover from a back injury. If a company switches to pneumatic conveyors, the employees would have less back injury risks from manually lifting heavy objects. Pneumatic conveyors can also reduce the need for using forklifts and other dangerous manually-operated machinery.
Just by adding a simple pneumatic conveyor system, a company can significantly cut back on their injury risk and liability. This could potentially save a company thousands of dollars each year.
Pneumatic conveying systems are attractive alternatives to mechanical conveyors, which use moving belts, spinning rollers or vibrating plates to move objects. Mechanical conveyors are excellent tools for the movement of large objects, but they are limited in their ability to safely and effectively move very small objects like fine silica, powders and granulated materials. Pneumatic conveyors are much better suited to powder handling than mechanical conveyors because the conveyance channels used in pneumatic conveyors are completely enclosed. Pneumatic powder conveyors feature no belts into which powders can be ground accidentally, nor are there any mechanical components between which they could become stuck. Bulk conveying processes like railcar unloading, bulk bag unloading and some food handling processes are tasks best suited to dense phase and dilute phase pneumatic conveying.Pneumatic conveyors are used for materials handling and transportation in a wide range of industries. The transportation of materials like flour, grain, seeds, coffee, fly ash, alumina, talc, plastic pellets and many other small products would be very difficult on an unenclosed, mechanical conveyor. Mechanical conveyors present too many opportunities for small objects to become scattered, spilled, ground up or otherwise dispersed in an undesirable way. These risks are especially threatening for food processing, pharmaceutical and other operations, whose products must meet strict standards of cleanliness and safety. Pneumatic conveyors offer food products manufacturers, pharmaceutical products developers, petrochemical processors, mineral processors and an extensive range of other industrial operations a means by which materials can be transported without the risk of product loss or contamination. Pneumatic conveyors can be custom-designed to meet the specific needs of a given operation and installed in a way that maximizes the conveyor's efficiency without impeding a facility's operations. Unlike many mechanical conveyor designs, pneumatic conveyors can be designed to move products between floor levels and around difficult angles. They can also be used outdoors and can move products between buildings.
Complete Pneumatic Conveying System - Whirl-Air-Flow Corporation
Pneumatic and Screw Conveyors - Flexicon
Pneumatic Conveying Components - Flexicon
Granulated Carbon Pneumatic Conveying System
Dilute Phase Pneumatic Conveying - Nol-Tec
Dilute Phase Pneumatic Conveying - Nol-Tec
- A tank that holds compressed air obtained from the system's air compressor in a dense phase pneumatic conveyor system.
Arching- A no-flow condition in which material forms a stable arch (bridge) across the bin
- The amount of force the atmosphere exerts upon the earth's surface. Air in a pneumatic conveyor with pressure greater than 14.7 psi is considered compressed, and pressure below 14.7 psi is considered a vacuum.
Attrition- The generation of fines or dust during solids handling. Highly sensitive solids prone to attrition include fragile granules (kitty litter), finished food products (chips), plastic pellets, and sugar or salt.
Bin- Container for bulk solids with one or more outlets for withdrawal, either by gravity alone or by flow-promoting devices which assist gravity
- In a pneumatic conveyor, the mechanism that removes or filters dust from system components, such as silos.
Bridging- Same as arching (a no-flow condition)
Bunker- Same as bin, often used in reference to storing coal
- Wheels that make the pneumatic conveyors portable.
Chute- Means of collecting or directing material stream, which, unlike a hopper, does not operate full
Cylinder- Vertical part of a bin which has a constant cross-section; can be any shape
Dense Phase Conveying- This occurs when particles are conveyed in the gas stream at a velocity that is less than the saltation velocity. Two general modes of flow can result in dense phase, and are referred to as plug or piston flow and moving bed (dune) flow.
Dilute Phase Conveying- This occurs when particles are conveyed in the gas stream at a velocity that is greater than the saltation and choking velocities.
Discharger- Device used to enhance material flow from a bin but which is not capable of controlling the rate of withdrawal
- A mechanism that changes/diverts material flow in pneumatic conveyors to a different direction.
Effective Head- Convenient way to express consolidating pressure by dividing it by bulk density
Elevator- Same as bin, often used in reference to storing grains
- The mechanism that transfers the conveyed material from the tubing to the receiving bin.
Expanded Flow- Flow pattern that is a combination of mass flow and funnel flow
Feeder- Device for controlling the rate of withdrawal of bulk solid from a bin
Flooding, Flushing- Condition where an aerated bulk solid behaves like a fluid and flows uncontrollably through an outlet or feeder
Flow Channel- Space in a bin through which a bulk solid is actually flowing during withdrawal
Flow Properties Test Report (FPTR)- Jenike & Johanson's bulk material characterization report typically containing results for a material's cohesive strength, bulk density range, coefficient of sliding friction against hopper wall surfaces, moisture content, particle size distribution, and permeability. These are the core characteristics needed to properly design a mass flow bin and feeder.
Fluidization- Using air or inert gas to fully aerate a fine bulk solid to allow it to behave as a liquid
- The total space that pneumatic conveyors occupy on the production floor.
Funnel Flow- Flow pattern in which solid flows in a channel formed within stagnant material
Hopper- Converging part of a bin
- A measure of the time rate of doing work.
Mass Flow- Flow pattern in which all solid in a bin is in motion whenever any of it is withdrawn
P-Factor- The ratio of the applied solids compacting pressure to the solids pressure during steady gravity flow
Pickup Velocity- This is the gas velocity at the pickup point of the conveying system where solids are introduced into the conveying gas stream.
- The tubes through which the conveyed material travels
to reach the intended destination. Pneumatic conveyor piping is arranged
in a network that travels through the facility, avoiding obstacles.
- The entire system of pneumatic conduits used to transfer air or other gases between various operating components of the pneumatic system such as pumps, valves and actuators of the pneumatic conveyors.
- Force per unit of area.
- A unit that measures the amount of pressure applied to an object.
Ratholing- A no-flow condition in which material forms a stable vertical hole within the bin
- Pneumatic conveyor component that obtains or
receives conveyed material.
- A mechanism attached to different pneumatic conveyors components that alleviates built up pressure created by the system.
- A mechanism responsible for releasing pneumatic conveyors materials under gravitational pressure.
Saltation Velocity- The gas velocity at which particles fully suspended within a horizontal conveying line begin to drop out of suspension and settle in a layer on the bottom of the pipeline.
Sifting Segregation- Separation of bulk solids by their size, shape, or particle density. There are several ways bulk solids can separate.
- A large container in which material is stored prior to conveyance.
State Diagram- The plot of pressure drop as function of conveying gas velocity over range of solids loading. This diagram defines conveying modes of dilute and dense phase transport.
- Sections of tubes containing various degrees of curvature
to facilitate the efficient maneuvering of pneumatic conveyors pipes,
through which conveyed materials are transported.
- A container in pneumatic conveyors that stores material to be conveyed at a certain rate. Dense phase pneumatic conveyor transporters often accept compressed air into the container to move or transport the material under pressure.