Your browser is out of date.

You are currently using Internet Explorer 7/8/9, which is not supported by our site. For the best experience, please use one of the latest browsers.

Back To Solutions


Negative Type Vacuum Conveying

PROBLEM:  Some plants are limited in both floor space and power availability. This problem is especially common in paper mills where there’s a need to efficiently move paper from winder to pulper. A number of similar applications face the same problem, requiring a high-speed, high-volume scrap handling system with less energy draw than Venturi-type systems.

SOLUTION:  Negative type conveying is an alternative design concept from Venturi or In-Line Fans. A popular form of this conveying solution was pioneered as an all-negative wet trim recycling system. With years of experience servicing these types of systems, we have engineered and installed many of these systems, as well as similar complete negative systems.

The original negative vacuum conveyance systems were developed to pick up recyclable ribbons of trim coming off high-speed paper winders and deliver them directly to pulpers. The ability of these systems to keep up with high-speed, high-volume needs without wearing out, made them a viable solution in similar applications. 

The most common versions of this system use vacuum power to pull material into a Compass WetVac separator placed between the fan and pick-up point. This separator has spray nozzles fed with both whitewater and fresh water to maintain pulper consistency.

Once material is moved into the Compassvac wet separator, gravity takes over delivering material to a pulper or other type of liquid discharge vessel. When delivering material to a dedicated pulper it provides a fluid vacuum seal enabling the system to pull material from the winder to the pulper. Since there are no belts, bearings, etc., and conveyed materials never come into contact with moving parts, these systems never wear out and are virtually maintenance free. When compared to Venturi-driven systems, negative type conveyance requires only half the horsepower to pull material through the system.

Negative Type Vacuum Piece Conveying systems require some type of pick-up nozzle to pull material from source through conveying tubes. A wide variety of valves or dump gates can be used to deliver material into the final destination.

Request A Quote




  • Lower energy consumption than Venturi-based vacuum systems due to lower horsepower requirements.   
  • No dust generation so there is no need for dust collection systems. 
  • No moving parts in material handling stream means lower maintenance costs. 
  • Systems never wear out. 


  • Conveyance tubing cannot be segregated since each system requires a dedicated discharge point. 
  • High up-front costs. 
  • Systems cannot handle slab material.

Winder Broke Shredding and Baling System

interactive image

Material Handling fan

Shredder and inlet chute

Cyclone Separator Unit

Baler Unit

Kraft Paper Material and Air Separator Unit with Wet Dust Collection System

interactive image

Wet Dust Collector Unit

Material and Air Separator Unit above Existing Pulper Unit

Slitter Dust Source Capture Vacuum System

interactive image

Slitter Dust Intake Hoods with Manifold

Portable Vacuum Unit with Dust Collection

Compass Guarantee:

We will guarantee that any Negative Type Conveying Material Handling System we engineer and install will perform as promised with minimum maintenance requirements. The complete Compass Systems Guarantee is available here.

View Compass Guarantee

System Audits: 

Please reach out to our technical team regarding a system audit, and potential Compass-engineered solution to ensure your material handling system is maximizing productivity and return on investment

Request System Audit

Similar Solutions

Have A Question?

Let Us Know How We Can Help You