Pneumatics conveying system for reliable operation

Choosing a pneumatic conveying system design is vital to ensure economic and reliable operation of any resin factory. A wide variety of pneumatic conveying systems are now available, giving processors all the advantages advanced technology can offer. A processor must be able to identify the system that works well and meet the requirements of the processing plant. Poorly designed systems can result to high maintenance costs and operational inefficiency. The length of the system, numbers of elbows and varying material properties all have a significant influence on the determination and sizing of a pneumatic conveying system.

When designing pneumatic conveying systems, many design parameters must be considered, according to Pelletron (www.pelletroncorp.com), a leading company that offers bulk material handling solutions and equipment to processors in various industries, including plastics, automotive, chemical, electronics, pharmaceutical, mineral and food. The company’s core business lays in pneumatic conveying systems and components, with special know-how in the prevention and reduction of fines, streamers and other contaminants.

For plastics manufacturing companies or compounders, the quality of the plastic pellets, prior to packaging, is most important. High contents of dust and streamers or angel hair in plastic pellets lead to customer rejects and lower market prices. The aim of each plastics manufacturer or compounder is the production of the highest quality resin grade with low dust content and no angel hair, at the lowest possible production cost. In order to help customers to achieve this goal, Pelletron developed a new economical conveying process, trade named pellcon3?.

Overview of conveying technologies
The dilute phase was the technology generally used for conveying, although there are now other systems available, such as slow motion dense phase, and Strandphase? conveying or special by-pass systems for sticky powders. The dilute phase conveying system uses high gas velocities at low pressures. and the conveyed product is completely dispersed in the gas flow. These types of systems are available as vacuum conveying systems, used for small conveying capacities and distribution of product from one source to multiple destinations, as well as for pressure conveying systems for larger capacities and longer distances.

The investment costs for dilute phase conveying systems are very economical, but the technology has a number of disadvantages. Due to the high velocity, the degradation of the conveyed pellets is high, which results in the generation of dust and streamers. The use of dilute phase for abrasive products results in wear of the conveying line and the pipe elbows. In former times, pressure dilute phase systems were used in combination with an elutriator, located in front or on top of the receiving silos, to remove the dust generated during conveying. These technologies were not completely satisfying, due to the quality problems of the conveyed pellets and high product loss in form of dust and streamers. In order to solve these problems, other technologies have been developed, such as dense phase conveying.

The dense phase, plug or slow motion conveying attempted to meet the demands of the market for high quality end products from systems that produce less degradation of the conveyed material and the piping. Moving pellets with low velocity and high pressure through piping systems was the next step in the development. The idea was to generate less dust and eliminate the dedusting of the conveyed materials. This was only partially successful. Dense phase eliminates the creation of streamers (angle hair), but creates very fine dust, due to the high wall friction undSneakers Ash Shoes