SEPARATORS IN TECHNICAL COLLABORATION WITH MAGOTTEAUX INTERNATIONAL S. A,, BELGIUM THE STURTEVANT SD - HIGH EFFICIENCY CLASSIFIER

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1 SEPARATORS IN TECHNICAL COLLABORATION WITH MAGOTTEAUX INTERNATIONAL S. A,, BELGIUM THE STURTEVANT SD - HIGH EFFICIENCY CLASSIFIER Sturtevant A Tradition of Engineering Excellence

2 SEPARATORS : THE THREE GENERATIONS THE FIRST GENERATION Examples: Sturtevant Whirlwind, Raymond Double Whizzer, Pfeiffer-Heyd, Polysius Turbopol, FLS Drawbacks: 1. Distribution is below the selecting zone. A lot of material falls down before being selected. 2. No control over airflow and very inefficient built in fan. 3. Poor cycloning effect in the outer casing: A lot of fines are returned, cross the stream of falling coarse particles, are caught and returned to the mill. The larger the separator, the worse the cycloning efficiency in the outer casing. 4. The selection zone is a horizontal ring delimited by the selection plates. The selecting action varies depending on whether the particles hit the outer part of the ring orthe inner part. 5. Narrow range of fineness adjustment. The non-adjustable speed separators in particular will require the removal or reinstallation of selection blades for each cement quality. THE SECOND GENERATION Examples: KHD (zub models) O & K Polysius Cyclopol Advantages: 1. With an external fan and small cyclones, most of the drawbacks of the first generation are solved. The external fan has a better efficiency and can be precisely controlled. 2. The external cyclones remove most of the fines from the air going back to the separator. However, the selecting zone is still a ring of selection blades with the above

3 THE THIRD GENERATION The third generation appeared in the first half of the eighties (1984) with Onoda (O'sepa) and Sturtevant. Sturtevant was already using the same principle on separators used in ultra-fine selection. The results were so much better that almost every mill manufacturer developed his own version: Sturtevant O&K FLS KHD Pfeiffer FCB Onoda Polysius T h e m a i n i m p r o v e m e n t compared to the second generation is the distribution. It is generally done on the top of the cylindrical selection zone. The cylindrical shape gives more time for the fine particles to be separated from the falling material. As a result, very few fines are returned to the mill and the tromp curves are better and have a very low by-pass. The Sturtevant SD separator is the result of over 20 years of research and development. It combines many technological features designed to maximize classification and efficiency performance at lowest operating and maintenance costs. The first patent application for this separator was submitted in 1974 and the first production machine was sold in Ever since the first installation, efforts have been made to continuously improve the machine. CEMENT

4 SD STURTEVANT Material Feed Chute Gear Unit Casing Distribution Plate (Rotating) Single Volute Air Inlet Louvre Assembly Rejector Cage Assembly (Rotating) Fines Chamber Tangential Air & Fines Outlet Volute Rejects Chamber

5 MECHANICAL FEATURES Lower power consumption Single volute air entry Low pressure drop State of the art dynamic seal Proven gear unit Trouble free rods system Bearings designed for low maintenance Easy access No wear on drive shaft Easy overall maintenance State - of- the - Art Dynamic Seal CEMENT Classification Principle

6 MINIMUM POWER CONSUMPTION REJECTOR CAGE DESIGN High efficiency air separation implies the manipulation of air as a means of separating small particles from the larger particles that appear in a closed circuit grinding system. The only two moving components that act on the air are an auxiliary air fan (responsible for the overall movement of air and material throughout the separator) and an integral rotating rejector cage (responsible for screening the larger particles while allowing the smaller particles to be transported by the flow of air) The rotating rejector cage, by nature of the direction of auxiliary air flowing through it, produces a "fan effect" which works against the separator vent air fan. For this reason, the Sturtevant SD separator cage implements the use of rods as the rejector mechanism instead of the blades used by other manufactures, thus minimizing the "fan effect". The concept of using rods was not agreed upon without realizing the effect on the separation process. As a matter of fact, our lab test indicate that the separation efficiency of a cage utilizing rods is equivalent to the blades when making a product below with a fitness below 9000 blaine. But most importantly, as the use of rods minimizes the fan effect of the cage, the power consumption of both the auxiliary fan and the separator cage is significantly reduced. STATE OF ART DYNAMIC SEAL The Sturtevant SD separator is provided The effectiveness of the seal is proven by the with a dynamic seal between the rotating cage excellent residues obtained (less than 5%on and the static fines chamber. The selection rods #325 at 3500 blaine, less than 1% at 4000 are extended below the bottom flange of the blaine in the most cases). The seal itself is easily cage so as to be located in front of the seal area, adjusted by shimming the classifier gear unit hereby minimizing coarse product residues. and it is partically maintenance free. SINGLE VOLUTE AIR INLET The Sturtevant SD single inlet volute is designed to ensure an even distribution of air around the entire circumference of the rejector cage. This is the fundamental objective required in order to achieve high efficiency air classification. It has been observed that multiple inlets can lead to an uneven distribution of air. However, if it were necessary to incorporate a multiple entry inlet volute, the Sturtevant SD configuration would easily allow for it. TANGENTIAL AIR AND FINES OUTLET VOLUTE The Sturtevant SD fines chamber volute design allows the outlet ducts(s) to be tangent to the fines chamber, thus including a smooth flow of air and fine material and subsequently minimizing the pressure drop across the separator. This configuration allows for both single and multiple outlet designs.

7 WEAR RESISTANT PARTS FOR THE STURTEVANT-SD LOCATION High material air loading areas i.e. fines chamber, outlet ducts and air inlet chambers. Distributor plate Louvres Tailings Cone Rotor Support Posts MATERIAL Basalt or Ceramic (alumina Oxide) liners 1/4" Abrasalloy Steel Abrasion Resistant Steel (AR Plate) Ring Liners Extra Heavy Pipe Liners CEMENT

8 MINIMUM MAINTENANCE PROVEN GEAR UNIT The Sturtevant SD separator gear unit (which includes all required separator bearings) has been installed on more than 3000 separators. This number includes the old generation Sturtevant Whirlwind separators because the same gear box, spindle and drive mechanism are used for both designs. When compared to the Whirl wind design, the SD drive shaft is considerably replaced by shorter since the distribution plate is located closer to the gear box. The gear unit and V belt drive configuration allows a higher motor speed for cooler motor operation. It also allows for standard motor sizes and speeds. In addition, the gear unit does not require any external cooling or bracing. BEARINGS AND DRIVE SHAFT All bearings associated with Sturtevant SD are located inside the gear unit casing. Therefore, there is no outboard bearing which exposes itself to dusty environment created inside the separator. When maintenance is required on the bearings, the gear unit can be easily lifted from the top of the separator and the bearings become directly accessible. This represents a major maintenance advantage over other separator designs. In addition, since the fines chamber is located below the rejector cage,the cage is located closer to the gear unit. Therefore, a shorter drive shaft is required which eliminates the need for a lower bearing. Another advantage of the configuration of the cage and the fines chamber is that it prevents the drive shaft from being exposed to the high speed mixture of the air and fine particles present in the fines chamber. Thus the drive shaft is wear free and maintenance free. REJECTOR CAGE DESIGN The rods of the Sturtevant SD separator cage are plain heavy gauge type that can be purchased anywhere. They can be freely rotated as dictated by the evolving wear pattern. After three 90 rotations (at least 4 years of use), they can be easily and quickly replaced by removing the separator top cover and the distribution plate liners. All of the rods can then be lifted from the top of the classifier. EASY ACCESS The Sturtevant SD contains several access doors allowing entry inside the rejector cage and the fines chamber for maintenance inspections. The gear unit, motor, and the rejector cage assembly can be removed easily by removing the holddown bolts for the gearunit support and cover, then lifting the entire assembly from the top of the separator. The maintenance for the rejector cage does not require re-manufacturing of the cage assembly since the rods are easily removable.

9 POSSIBLE FLOW - SHEET BAGHOUSE COLLECTION AND SEPARATE MILL VENTING BAGHOUSE COLLECTION AND MILL CONNECTED TO SD CYCLONE AND SEPARATE MILL VENTING CYCLONE COLLECTION AND MILL CONNECTED TO SD ADVANTAGES OF THE BAGHOUSE COLLECTION a) Better cooling b) Better air cleaning ADVANTAGES OF A SEPARATE MILL VENTILATION : a) Better fineness control b) No balancing of airflow between separator and mil c) Higher cooling capacity d) Slightly lower power consumption on fan(s) e) Slightly better efficiency DISADVANTAGES OF THE BAGHOUSE - COLLECTION : a) Takes more room b) Requires more maintenance DISADVANTAGES OF A SEPARATE MILL VENTILATION : a) Higher investment b) Higher maintenance cost c) Higher space and volume required CEMENT

10 NEW DEVELOPMENT AIR SWEPT (ASW) SEPARATOR A high efficiency separator having specific feature to suit air swept ball mill application is now designed by M/s. Magotteaux International (S.A.), Belgium and the same is made available by WIL in collaboration with Magotteaux International (S.A.), Belgium. The specific features of the separator include: 1) Bottom entry of dust laden air from ball mill exit 2) Cage rotor design 3) Top seal to ensure effective control on separation of oversize particles 4) Wear protection provided on all wear parts. The design is recommend for air swept mills so as to confine advantages of compact layout and high separation efficiency.

11 NEW DEVELOPMENT AIR SWEPT (ASW) SEPARATOR Motor 2. Reducer 3. Air outlet 4. Rotor 5. Guide vanes 6. Air Inlet 7. Grits Outlet CEMENT

12 STURTEVANT S-D HIGH EFFICIENCY SEPARATOR NOTE : The above figures are given as guidelines only, and are subject to change without notice. For more precise information concerning your particular application we request that you forward all the relevant material and process data. Alternatively, we can arrange to run a pilot plant test using a sample of your materials. WALCHANDNAGAR INDUSTRIES LTD. MARKETING & PROJECT OFFICE WALCHAND HOUSE,15 / 1 / b-2 G. A. Kulkarni Path, Kothrud, Pune INDIA Phone : Telefax : wilcement@walchand.com Web site : BRANCH OFFICES WALCHANDNAGAR INDUSTRIES LTD. 201 Milap niketan, Second Floor, 8-A, Bahadur Shah Zafar Marg, New Delhi Phone : ,92 WALCHANDNAGAR INDUSTRIES LTD A, Ground Floor, II Arcadia Apartments, Eden Bagh, Ramkoti, Hyderabad Phone : WALCHANDNAGAR INDUSTRIES LTD. 153, Anna Salai, Agurchand Mansion, Chennai Phone : WALCHANDNAGAR INDUSTRIES LTD. 50/A,Gurupada Halder Road, Kolkata Phone : Ruta.WIL.Cement