Convey pellets around corners without generating dust & fines.* It's a common problem that goes by a lot of names: dust, fines, streamers Streamers is a play by David Rabe. The last in his Vietnam War trilogy that began with The Basic Training of Pavlo Hummel and Sticks and Bones , angel hair. The resin arrives at your plant with a guaranteed level of cleanliness from the resin supplier, but by the time it gets into your silo or machine hopper, it's contaminated contaminated, v 1. made radioactive by the addition of small quantities of radioactive material. 2. made contaminated by adding infective or radiographic materials. 3. an infective surface or object. with fine particles Fine particles are an air pollutant mainly produced by cars running on diesel. Other sources are the combustion of fossil fuels in power plants and various industrial processes. . They overheat o·ver·heat v. o·ver·heat·ed, o·ver·heat·ing, o·ver·heats v.tr. 1. To heat too much. 2. To cause to become excited, agitated, or overstimulated. v.intr. in the machine barrel, causing bubbles, burning, and black spots. The basic cause of the problem is well known: Pneumatic conveying systems drag pellets through piping on a stream of air moving at around 60 mph. When the pellets come up against a 90[degrees] bend, they hit hard, smearing and fracturing. A number of types of "elbows" have been designed to reduce this problem, with some success, but fines and quality problems have not disappeared altogether. Now there's a new, patented approach based on research at the University of Pittsburgh into the aerodynamics aerodynamics, study of gases in motion. As the principal application of aerodynamics is the design of aircraft, air is the gas with which the science is most concerned. of pellet flow. That research has produced the "Pellbow" from Pelletron Corp. Slow down for the curve The Pellbow briefly changes the pellet flow from dilute phase (low pressure, high speed) to dense phase (high pressure, low speed) and back again to dilute phase. This is accomplished by expanding and then contracting the cross-sectional area of the elbow. This accomplishes two things: First, the pellets slow down, but don't stop, while making the turn. Second, pellets don't hit the hard wall of the pipe in the turn--rather, they bump into a soft body of slow-moving pellets. As a result, there's much less wear on the elbow when running abrasive glass-filled materials. What's more, the Pellbow reportedly is 100% self-cleaning when the pipe system is purged. Pelletron claims that the Pellbow virtually eliminates formation of fines and streamers in pipe elbows, though not in straight sections of pipe. As a rule of thumb, a standard elbow will produce as many streamers as 100 ft of horizontal pipe. Early this year, Pelletron hopes to prove its claims through a scientific comparison with a standard elbow. Pelletron will use a new method it developed that can measure dust as small as 0.001 microns. This approach directs a high-velocity water spray onto pellets held on a screen. The water washes off the fines, which then can be weighed. This technique is being developed into a new standard test method for dust contamination Noun 1. dust contamination - state of being contaminated with dust contamination, taint - the state of being contaminated 2. dust contamination - the act of contaminating with dust particles by ASTM International ASTM International (ASTM) is an international standards developing organization that develops and publishes voluntary technical standards for a wide range of materials, products, systems, and services. , West Conshohocken, Pa. The Pellbow is made of aluminum, 316 stainless steel stainless steel: see steel. stainless steel Any of a family of alloy steels usually containing 10–30% chromium. The presence of chromium, together with low carbon content, gives remarkable resistance to corrosion and heat. , or a ductile iron Ductile iron, also called ductile cast iron or nodular cast iron, is a type of cast iron invented in 1943 by Keith Millis[1]. While most varieties of cast iron are brittle, ductile iron is much more ductile, as the name implies. casting. Prices are said to be in the middle range for elbows on the market. More dust-busting news Another recent development from Pelletron is its patented FlowEnhancer, a straight blow-offpipe section that is inserted into a pneumatic conveying line. It reduces the velocity of the conveying air while increasing the conveying capacity of the line, Pelletron claims. The purged air is filtered before it is released. The result is said to be less noise and fines and increased flow rates. NEED TO KNOW MORE? Pelletron Corp., Lancaster, Pa. (717) 293-4008 * PT Direct: 774MZ |
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