BM&M High Speed Gyratory Screening Equipment

CounterFlow Chip Screen High Efficiency Gyratory Screener

BM&M Screening Solutions has been building high efficiency CounterFlow Chip Screens since 1987. The CounterFlow Chip Screen is a unique concept that provides a tremendously efficient screen in a relatively small footprint. Thanks to a multi-tier design, CounterFlow high-speed gyratory screeners provide a total of 28’ in screen length, with the footprint of a 14’ standard chip screen.

Double the Screening Area and Efficiency over Standard Chip Screening Systems

Our double-length design is the key to the screen’s outstanding efficiency. In the two-level design, the upper layer screens the material once and, from an elbow where the two levels meet, feeds the filtered material to the lower screen, where it is filtered again. Both screens move simultaneously, powered by a single gyratory motor. The patented BM&M gyratory drive design can operate at far higher speeds (up to 300 RPM), and with larger stroke, than the drives in chip screens that utilize conventional reciprocating (back-and-forth) motion.

In modern sawmills, where fines content can often be as high as 30%, our CounterFlow gyratory screening system has proven to deliver the performance and efficiency users need, without losing valuable fiber. The CounterFlow Chip Screen is a prime solution for numerous applications in the forest industry and other markets.

Applications for CounterFlow Chip Screener Systems




  • Wood chips
  • Pins
  • Sawdust
  • Flakes

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CounterFlow Chip Screen Custom Constructions

We offer the CounterFlow Chip Screen in a variety of styles and configurations, including custom constructions that will maximize your screening performance. Multiple screen combinations allow for complete screening, sifting, and sorting of your most challenging materials. Common setups include:

Three-Deck Twin Fines Chip Screener

The ultimate in fines removal, a three-deck twin fines CounterFlow Chip Screen provides double the fines screen area of other similarly-sized chip screeners. This configuration is popular in modern curve saw gang mills and chip-and-saw mills with exceptionally high sawdust content in their unscreened fiber.

Two-Deck Pulp Chip Screener

The two-deck pulp chip CounterFlow Chip Screen setup is ideal for applications where a moderate level of fines is anticipated and where the amount of space is limited and/or discharges need to be directly below the infeed.

Three-Deck Chip & Sawdust Screener

We recommend the three-deck chip and sawdust CounterFlow Chip Screen configuration for applications where the removal of pin chips is paramount, or where a mill has two customers with very different chip quality requirements. 

CounterFlow Chip Screen Specifications



    # of Decks

  • Width: 3 ft. to 10 ft.
  • Length: 8 ft. to 14 ft.
  • Total:  up to 140 ft2
  • 2-deck and 3-deck configurations available

Chip Screen Construction Design & Materials

  • Welded steel construction for drive/screen assembly
  • Bolted structural steel support stand (floor-mounted standard)
  • Fines pan air lancing ports
  • Infeed landing deck with bolted steel wear liner
  • Mild steel materials, fully stress relieved
  • Screen access door for quick screen element changes
  • Separate discharge chutes for each filter/screen
  • Optional stainless steel materials for pans and chutes
  • Optional double-single construction
  • Optional open bottom construction (no fines pan)
  • Optional suspended installation
  • Optional dust cover

Optional Ball Deck Screen Cleaning

BM&M CounterFlow Chip Screen systems can be equipped with special “ball decks” to help clean fines screens with openings smaller than 3/16” and to keep screens clear when working with moist and/or sticky materials. The gyratory screening motion propels captive balls to constantly strike the underside of the screens to dislodged any wedged-in particles or plugs. The 2” diameter balls are manufactured from synthetic rubber or a special compound material, depending on the application.

Contact Us for CounterFlow Chip Screen High-Speed Gyratory Screeners

CounterFlow Chip Screen systems are custom engineered for high efficiency and high fines applications in your unique application. They deliver high efficiency screening for sawmills, paper mills, and elsewhere. Request a quote on a custom CounterFlow Chip Screener, or contact BM&M Screening Solutions to discuss your screening requirements.

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