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Coru-Dek® III Vacuum Cylinder

The CORU-DEK® III technology is the first of GL&V’s modern end-drainage machines. They were originally designed as a direct replacement for some of the original Center Valve Machines, Pipe Machines and CORU-DEK® I’s systems. With over 300 of these units sold word wide, GL&V has perfected the design and performance of this cylinder. The standard CORU-DEK III equipment sports a Drive Trunnion, Rear Shaft design, end-drainage design, and the legendary GL&V Anti-Rewet Decking.

With the ability to be designed with numerous shaft- trunnion or trunnion-trunnion designs as well as the capability of being manufacture in a variety of high grade stainless steel materials, the CORU-DEK III technology should be your choice for your next replacement cylinder.

Developed in 1991, the CORU-DEK® III Vacuum Cylinder has been established by GL&V with industry proven technology to provide high consistency stock discharge for improved washing and thickening. The CORU-DEK III design incorporates the industry proven louvered corrugated decking and end drainage design. Our corrugate deck eliminates rewetting of the pulp mat and enhances vacuum control, while the end drainage design eliminates costly center pipes.

The CORU-DEK III design can be manufactured in a variety of sizes with GL&V offering standard sizing in 8’ diameter, 9’6’’ diameter, 11’6’’ diameter and 13’6’’ diameter machines ranging from 8’ to 30’ in length with custom sizing available. They are built with a patented integral head design that insures structural integrity and eliminates concerns of internal leakage. They also incorporate an end drainage style system that eliminates center pipes to allow for material and weight savings. The CORU-DEK III systems are typically manufactured with a rear shaft and drive trunnion design. Using this set up allows the reuse of existing drive and bearing arrangements. GL&V also offers the CORU-DEK III system in a duel trunnion arrangement to suit original drum configuration for maximum cost savings.

GL&V has been at the leading edge of furnishing shaft-mounted drives on pulp washing equipment, including Vacuum Washers, Pressure Washers, and Twin-Roll Presses. For Vacuum Washers, we have used a number of different purchased gear drives in the past, but have established Rexnord as our standard planetary gear box. The shaft mounted drive is standard with the CORU-DEK III system. It can be used on the rear-end of the CORU-DEK III Vacuum Washer.

  • CORU-DEK® III Vacuum Cylinder Operation
    • Vacuum washers are generally used for displacement washing or pulp thickening. All vacuum washers use pressure differential to pick up a fiber ‘mat’ on the decking surface of the cylinder. From there filtrate from washing showers passes through the fiber mat and eventually through the face wire onto the corrugated drainage deck with circumferential channels. The deck channels carry the filtrate through louvered accelerators to longitudinal channels. Channels are formed by the deck sections support grids along the drum surface. The deck support channels direct the filtrate to the cylinder head where radial channels direct the filtrate to the valve seat. A cylinder valve with preset clearances dictates vacuum application and shutoff. Once past the valve filtrate passes directly to the discharge elbow. The discharge elbow is connected to the drop leg leading to a filtrate tank below. The siphon action of the drop leg arrangement creates the required pressure differential or vacuum.
  • Deck Design
    • Introduced in 1968, the corrugated deck traps filtrate, preventing sheet re-wetting in the sheet take off zone, thus maintaining high consistency. The louvers direct the flow to the end of the drum. The directing action of the louver and the hydraulic control of the end drainage bucket, assist flow and provide a smooth path to the valve area, reducing air entrainments.
  • End Drainage Design
    • The end drainage design does not require the center drainage ports and internal piping of conventional vacuum machines. The elimination of the center drainage ports allows a continuous cylindrical construction. This reduces the number of welded seams resulting in a stronger unit. Additionally, fewer seams help to eliminate any possibility of leaks. 
  • Shaft and Trunnion Designs
    • Shaft and Trunnion sizes and metallurgies depend on a variety of conditions. While sizing is typically based off of original cylinder design and length, while metallurgy depends on existing and/or forecasted process conditions. Sizing of the shafts and trunnions can be made to suit any existing cylinder trunnion-shaft or trunnion-trunnion arrangements.
  • Shaft Mounted Drives
    • The standard drive arrangement employs a proprietary double torque arm arrangement developed by GL&V with a hollow-shaft reducer and shrink disc, a top mounted motor mount with sheaves, timing belt, and guard.
      The requirements for furnishing a shaft-mounted drive on the CORU-DEK®III are to extend the rear shaft length to accept the gearbox, provide the bearing base with torque arm brackets, supply a new bearing cover for the through-shaft, and convert the existing worm gear drive housing to a simple trunnion bearing housing.
  • Material Selection
    • GL&V offers the CORU-DEK III cylinder in Steel, 304L, 316L, 317L, 6-7% Moly , Duplex 2101, Duplex 2205, and Duplex 2507. With our legacy of supplying OEM drums for numerous Pulp and Paper applications, we would be happy to provide our recommendation for metallurgy for your specific process.
  • Direct Replacement
    • GL&V can design a drop in replacement CORU-DEK® III system for any cylinders that are 8’, 9’6’’, 11’6’’, or 13’6’’ diameter and up to 30’ in length that will utilize most existing drive and bearing arrangements while also fitting in the existing foot print.
  • Cost Savings
    • Elimination of internal piping due to end drainage design.
  • Anti-Rewet Decking
    • As a standard on the CORU-DEK III design, GL&V’s anti-rewet decking prevents rewetting while also reducing air in system, increasing vacuum, and ultimately allows for improved sheet pick up.
  • Experience
    • As the true OEM of vacuum washers, GL&V has sold over 300 CORU-DEK III systems word wide. Having experience in numerous pulping applications such as Kraft, Chemical, and Dissolving Pulp, GL&V has the experience and technological makeup to provide you with the best replacement cylinder options available.

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