Common questions about pneumatic conveying

 

Pneumatic dense phase conveying is a common method of transferring powders, granules, and other dry bulk materials, understanding this pneumatic conveyingsystems can be a challenge. We will addresses pneumatic conveying questions frequently asked by our customer in dry bulk materials processing and handling factories.

 

 

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Pneumatic conveying system transfers powders, granules, and other powdered bulk materials through an pipeline. Start force for this transfer comes from a combination of pressure differential and the flow of air or nitrogen.  The system’s basic elements include a motive air source i a compressor,  feeder, conveying pipe line, termination hopper or silos  and a dust collection system or jet pulse filters.

The most common materials transferred by pneumatic conveying systems are sand, flour, cement, gypsum, starch, powdered coal, plastic pellets, hundreds of chemicals, food products, and minerals can be pneumatically conveyed. These materials are usually fairly dry; materials in slurry form or paste form typically are not suited to use pneumatic conveying.

 

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Compressed air  required to move material through a pneumatic conveying system, but in this case the energy is supplied by pressure differential and airflow in a pneumatic conveying system, the air pressure in the conveying line is changed by the system’s air compressor, which generates pressure. Where the air compressor is located in the system determines whether it generates one or the other: When located at the system’s start, the air compressor pushes air through the system and the system operates under pressure. By controlling the pressure inside the system, the system can successfully transfer powdered materials.

 

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Firstly checking at mechanical conveying systems. Conventional mechanical conveying system runs in a straight line, for minimal directional changes, and each directional change typically requires new motor and drive. Mechanical conveying system may be open rather than enclosed, potentially generating dust. And also have large number of moving parts, which usually require frequent maintenance. Mechanical conveying system equipments also take up a lot of valuable place in a plant.

But  pneumatic dense phase conveying system uses a simple, small diameter pipeline to transfer material. The pipeline can be arranged with bends to fit around existing equipment, giving the system more layout flexibility, and the system also need small place. Pneumatic conveying system is totally enclosed and just has few moving parts.

 

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Pneumatic conveying system typically requires  more horsepower to operate than an equivalently sized mechanical conveying system. Pneumatic conveying system also requires more bigger dust collection system than a mechanical conveying system because the pneumatic system has to separate the conveyed material from the conveying air at the system’s end.

 

Aldo some  materials have characteristics that make them difficult to convey in a pneumatic system. For example a large particle size and high bulk density, such as rocks, and an extremely sticky material.

 

 

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Dense phase

The best dense-phase conveying system would extrude material with enough pressure to transfer it in one long, continuous piece through the pipeline’s entire length this cycle continues until all the material required for the process has been transferred.

Usually  dense-phase systems have air injectors or air assists fixed along the conveying line an air injector works by injecting compressed air or another gas    into the conveying line. The added air can clear any plugs caused by low air volume or pressure, eliminating the chore of dismantling the line to remove plugs.  Air injectors must be designed as fail-safe check valves to prevent the conveyed material from intruding into the injectors’ compressed-air supply. And also air injectors along the conveying line can also be used to gently restart flow when material is left in the line after the conveying cycle. This is a particular advantage for a system handling an abrasive or friable material or a material blend. When the system is restarted without supplementary air, the higher-speed material flow can cause an abrasive material to produce excessive and premature wear on the conveying line and other material contact components. This higher-speed flow can also damage a friable material, resulting in unacceptably high amounts of particle attrition. It can also deblend a mixture of materials with different particle sizes and bulk densities. Using supplementary air in the line can not only prevent wear, attrition, and deblending problems when a power outage or other event abruptly shuts down the conveying system when it’s full of material, but can provide more system design flexibility for an application where you want to intentionally leave material in the line between cycles.

 

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The biggest factors to consider with our engineers.

The first thing to  your material’s characteristics, material’s particle size, shape, bulk density, moisture content, abrasiveness, friability, cohesiveness, hygroscopicity, static charge, explosivity, toxicity, melt point, and etc.

The second  consider how the system will fit into your location and plant environment. -

Third factor to consider is what material transfer volume the system must achieve to meet your application requirements.