Part of the
Nederman Group

Metal Chip Wringers (Centrifuges)

National Conveyors Vari Screen® Adjustable Bowl Metal Chip Wringer/Centrifuge

How It Works

Wet metal chips enter the centrifuge through the feed inlet hopper (1) and delivery chute (2) from which they are uniformly distributed across the surface of the rotating bowl (3), aided by feed distribution vanes. Newly arrived wet metal chips move outward across the rotating bowl surface, discharging onto a rotating, cylindrical wedge wire drainage screen element (4). New metal chips move onto the screen surface displacing chips which have previously arrived. Separation of cutting fluids occurs as chips pass over the screen surface. Dewatered metal chips report to the solids discharge chute (5) from which they are normally collected by a conveyor. Cutting fluids passing through the drainage screen flow downward through liquid collection chute (6) for separate collection.

Features and Benefits

The bowl may be adjustably positioned so as to provide a particular drainage screen exposure which results in the desired product dryness.

550 gravities of centrifugal force and uniform feed distribution assure optimum dewatering and de-oiling performance.

When the centrifuge is coasting to the stopped condition, centrifugal forces acting on the chip load gradually decrease until the weight of the residual load exceeds the declining centrifugal forces permitting chips to discharge under the effect of gravity. The machine is left in a clean condition for the next start-up. There is no potentially troublesome sludge accumulation or oxidation and agglomeration of residual material.

All internal wetted parts can be inspected in 5 minutes. Simply open the hinged front door. The motor and drive components are externally mounted. Areas subject to abrasive wear are fitted with long wearing, replaceable manganese steel alloy liners. Guards, Safety Placards and Safety Devices may have been removed for the purpose of clarity.

Adjusting The Bowl

Usefully, by simple external adjustment, the internal bowl (3) may be moved laterally back and forth over the metal chip drainage screen surface (4) thereby establishing the best choice of screen exposure for optimum liquid removal and the achievement of desired metal chip product dryness. Positioning of the bowl is easily accomplished by rotation of the external adjustment mechanism (7).

Internal Rotating Bowl is moved forward or backward by turning an external adjusting nut.

Closed Exterior View

National Vari Screen® adjustable bowl, self-cleaning metal chip wringer/centrifuge is designed for continuous heavy duty service. "The heart of the metal chip processing system"

Guards, Safety Placards and Safety Devices may have been removed for the purpose of clarity.

Self Cleaning Action

Open door view showing self-cleaning action during shut down of the chip wringer. Upon completion of the shut down no material build up is left within the machine. Also with the door open, note the ease of inspection and access to all material contact surfaces—bowl, screen element, feed and discharge chutes.

Superior Metal Chip Processing Performance With Optimum Ease of Maintenance

Guards, Safety Placards and Safety Devices may have been removed for the purpose of clarity.

Horizontal Bowl Fixed Screen

A useful choice when the adjustable bowl feature of the Vari Screen® model is not required.

Operating method and other features/benefits are similar to those of the Vari Screen® model except for the fixed positioning of the bowl and fixed drainage screen exposure.

National horizontal bowl, self cleaning metal chip wringer (centrifuge). Sizes for different capacities are available. Contact National Conveyors to discuss your application.

Guards, Safety Placards and Safety Devices may have been removed for the purpose of clarity.

Vertical Bowl, Pneumatic Discharge Metal Chip Wringer

4 Sizes Available
VD40 (10cfh) - TI30 (40cfh) - TI42 (80cfh) - TI50 (240cfh) cfh-cubic feet per hour nominal capacity

Wet metal chips containing cutting fluids are fed into conical inlet hopper (1) and report to the bottom of rotating bowl (2). The bowl is mounted on shaft and bearing assembly (3), driven by a non-slip timing belt and sheave assembly (4) and motor (5). Metal chips and fluids arriving within the bowl are immediately subjected to intense centrifugal force causing both chips and fluids to be thrown against the bowl surface. The arrival of new metal chip feed causes chips already present in the bowl to be displaced upwardly along the bowl surface. As metal chips and fluids arrive at the upper periphery of the bowl, they pass across a wedge wire screen through which cutting fluids pass into a fluid collection chamber (7) for separate collection. Dewatered metal chips pass across the screen, reporting to the chip discharge chamber (8) from which they are pneumatically expelled by the airflow generated by fan blades (9) fixed to the top of the rotating bowl (2). Airborne chips flow through discharge pipe (10) for collection in a container or truck. The airflow generated by the wringer is normally adequate for conveying metal chips for a distance of up to about 100 feet or 30 meters.

Guards, Safety Placards and Safety Devices may have been removed for the purpose of clarity.

Batch Type Metal Chip Wringer

National-Rousselet metal chip wringler for high capacity manual (batch) processing of metal chips.
The National-Rousselet “TIMESAVER” chip wringer (centrifuge) is an economical and efficient machine for manual, batch processing of metal chips and turnings. An excellent choice for smaller machining operations. Three high capacity (labor saving) models are offered. Rugged 3 point suspension. Controlled acceleration and smooth braking. There is no other comparable batch type chip wringer.

High Capacity Designs For Labor Savings
To minimize time and manpower associated with batch wringing of chips, National offers three high capacity models. Frequently, one “TIMESAVER” can replace several smaller wringers, thereby releasing operators for revenue producing work while also freeing floor space for other uses.

SC50 20” (510 mm) 1.6 cu.ft. (46 L)
SC70 27” (685 mm) 3.5 cu.ft. (102 L)
SC85 32” (812 mm) 5.6 cu.ft. (162 L)
SC100 40” (1,000 mm) 10 cu. ft. (290 L)


Engineered Excellence Since 1933 in:

  • Metal Chip Processing
  • Ash Handling Systems
  • Bulk Material Systems

ISO 9001:2015 Certified
ISO 14001:2015 Certified