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Ask Orange TM Provides solutions to process problems How To Choose & Use Magnet

Ask Orange TM Provides solutions to process problems How To Choose & Use Magnetic Separators Choose & Use Magnetic Separators Complete guide to Magnetic Materials and Separation Equipment It’s not magic...it’s ERIEZ World authority in advanced technology for magnetic, vibratory and inspection applications. SB-95A HOW TO CHOOSE AND USE MAGNETIC SEPARATORS Page INTRODUCTION 1 1. MAGNET MATERIALS & STYLES 2 2. APPLICATION CONSIDERATIONS 4 3. TYPE OF MATERIAL BEING PROCESSED 4 4. SEPARATION EQUIPMENT - PLATE MAGNETS 5 5. SEPARATION EQUIPMENT - GRATE MAGNETS 7 6. SEPARATION EQUIPMENT - LIQUID LINE TRAP MAGNETS 7 7. SEPARATION EQUIPMENT - PNEUMATIC LINE RF MAGNETS 8 8. SEPARATION EQUIPMENT - SUSPENDED MAGNETS 8 9. SEPARATION EQUIPMENT - MAGNETIC PULLEYS AND DRUMS 11 10-. SEPARATION EQUIPMENT - HIGH INTENSITY MAGNETICS 11 11. SEPARATION EQUIPMENT FOR NONFERROUS METALS 12 Ask OrangeTM is a collection of process solution case studies and how-to reference manuals designed to improve understanding and simplify specifying sophisticated magnetic, vibratory and metal detection equipment needed in most process industries. Most of this equipment requires an understanding of its intended use in order to determine proper application. The “Professor” icon has been developed to help customers identify Ask OrangeTM material in printed trade publications, company literature and on its web site. The Ask Orange concept and related images are a tribute to the company’s founder, Orange F. Merwin, and his innovative ideas using magnets to remove metal contamination from various process ﬂows. ® HOW TO CHOOSE AND USE MAGNETIC SEPARATORS The use of magnets for removing ferrous contaminants in an industrial environment ﬁrst began in the 1940s when Orange F. Merwin developed a ﬂat magnetic product to help farmers trap and remove metal contaminants from their grain chutes. At the time, unwanted or “tramp” metal in the grain ﬂow often created a spark that would ignite the explosive dust causing ﬁres… sometimes with catastrophic results. Orange’s early version of today’s plate magnet was a huge success and led to the founding of Eriez Magnetics. After more than 60 years, Eriez remains the world’s authority in magnetic separation solutions for industry. Ferrous metal contamination damages process equipment and creates impure product that must be scrapped or sold at less than full value. This metallic contamination may come from a variety of sources. Incoming products may contain contaminants from the transportation vessel used to deliver the product, such as a truck bed, rail car, barge or ship hold. The contamination may originate within the plant due to material processing, grinding, crushing or general abrasion. The problems associated with ferrous metal contamination can be reduced or eliminated by using magnetic separation equipment. Magnetic Separators, available in a wide variety of designs, will remove ferrous material such as nails, rust, scale, bolts, welding rod and other contaminants from dry or liquid products. The proper use of this equipment will reduce or eliminate metallic contamination from the process. Selecting the proper magnetic separator requires an understanding of magnetic properties, the process application and environmental elements that exist in each speciﬁc installation. This guide provides a basic understanding of how to choose the proper magnetic separator for different process requirements. Beginning with a magnet material overview, How to Choose and Use Magnetic Separators covers various types of materials being processed, numerous magnetic separation techniques, application considerations and a wide variety of magnetic separation equipment currently available. Did you know? In order to help customers select the proper equipment, Eriez operates the industry’s largest laboratory of magnetic separation equipment. Here, materials are sampled to ensure product and/or process purity that meets each customer’s speciﬁc requirements. Contact your Eriez representative to arrange a sampling. Tour the lab at eriez.com, click: Tour Eriez - USA © 2007 ERIEZ MAGNETICS ALL RIGHTS RESERVED 1 1. MAGNET MATERIALS & STYLES PERMANENT Magnet material generally refers to the magnetic pressings or castings used to develop the magnetic ﬁeld within the separator. This material may be cut and arranged in a linear fashion using other materials to create a magnetic circuit. Depending on the desired outcome, circuits may be designed to cast a shallow- wide magnetic ﬁeld; a deep-narrow ﬁeld or anywhere in between. This is why it is often difﬁcult to compare competing products made of only similar material. Once the circuit is assembled, it is usually encased within stainless steel to protect the magnet material from wear associated with product ﬂow, damage or from contaminating the feed material. Since the 1940s, there has been substantial change in the materials used to manufacture permanent magnetic separators for industry. The following is a brief description of the most common magnetic materials used over the past 60-plus years. ALNICO Alnico is one of the earliest magnet materials used for ferrous separation. These magnets are commonly recognized by their horseshoe shape. This material is a casting of Aluminum, Nickel, Cobalt and Iron. Although seldom used today, as there are more economical magnet sources, Alnico may still be used in applications involving temperatures in excess of 400 degrees Fahrenheit (204 degrees Celsius). This material is comparable in strength to ceramics and used to remove relatively large pieces of ferrous metals, such as nuts or bolts. CERAMIC During the 1960s, problems in South Africa drove up the price of Cobalt forcing manufacturers to search for an Alnico substitute. It was then that manufacturers began using Ferrite ceramic pressings in their magnetic assemblies. Ceramic pressings are easy to work with because they can be cut in all directions, assembled into a circuit and then charged as a complete unit. Ferrite pressings became the standard in permanent magnetic separators until the early 1980s. Ceramic magnet circuits work best when the goal is to remove relatively large pieces of ferrous metal contamination. 2 Did you know? The strength of the ﬁeld produced by a magnet is usually measured in units called Gauss. Very strong magnetic ﬁelds may be measured in units of Tesla, where 1 Tesla equals 10,000 Gauss. For refrence, the magnetic ﬁeld of the Earth is about 0.5 Gauss. RARE EARTH The term, Rare Earth, is a misnomer. A rare earth magnet derives its name not because it is rare, nor because it is earth. It is named “Rare Earth” because part of its make-up is one of the Lanthanide elements of the Periodic Table between 57 and 71. There are 14 elements referred to as “The Rare Earth Elements.” Samarium Cobalt was the ﬁrst such material used in the early 1980s. The next material on the market was Neodymium Iron Boron, called “Rare Earth” because Neodymium, like Samarium, is one of the Lanthanides. Today, Rare Earth magnetic circuits produce a magnet force more than 10 times that of ceramic magnetic circuits. The graph below provides a history of magnetic material improvements. Eriez’ Rare Earth Material develops an extremely high surface force to enable the magnetic circuit to remove very ﬁne or weakly magnetic contamination such as rust, scale or even work-hardened stainless steel from a product ﬂow. High strength Rare Earth Separators are extensively used by food, chemical and pharmaceutical processors requiring the highest levels of product purity. ELECTROMAGNETS For larger industrial separation applications, Eriez developed electromagnetic separators. The popular round-core electromagnet uses round aluminum or copper wire in an oil-ﬁlled assembly to generate a powerful electromagnetic ﬁeld. These electromagnets efﬁciently remove ferrous metals in heavy industrial applications like coal, limestone, sand and other aggregates. These large scale magnets are available in a variety of conﬁgurations including oil and air-cooled; round, hollow and rectangular core; explosion proof; even cryogenic superconducting magnets capable of producing the world’s strongest magnetic force for separation applications. 3 Did you know? Eriez was the maker of the World’s Strongest Suspended Electromagnet operating at China National Coal in Qingdao. This Superconducting Electromagnet produces 4000 gauss at 550mm (21.65 inches). That’s nearly twice the strength of any similar magnet! See it at eriez.com, click: Press Room - 3/15/02 2. APPLICATION CONSIDERATIONS TEMPERATURE Permanent magnetic materials lose strength when exposed to elevated temperatures. Some losses are reversible in that when the temperature is returned to normal, the magnetic strength returns. Permanent magnets heated beyond certain temperatures (which depend on the speciﬁc material) may also suffer irreversible loss: a reduction in strength that cannot be recovered by cooling. When specifying a magnet application, it is important to note the ambient as well as any Clean in Place (CIP) temperatures to ensure a proper magnet design suitable for long term separation performance. FLOW RATE Magnetic separators perform best when the contamination is presented to the surface of the separator. It is best to select a magnetic separator that provides for a thin burden depth over or under the magnet to ensure the magnet will have the best opportunity to capture the ferrous contamination. FLOW CHARACTERISTICS Many products exhibit different ﬂow characteristics when damp or moist. Are there large chunks that may plug an opening or gap in the separator? Will the product ﬂow freely through the selected magnetic separator? For example, brown sugar with any signiﬁcant moisture content will not uploads/Geographie/ guide - 2023-05-29T190715.194.pdf