Royal Filtermist FX-1200 and FX-275 Stainless Steel

Royal Filtermist - The world leader in metalworking pollution control.

The Royal Filtermist is available in four sizes ranging from 275 - 1200 cfm, and its flexible design enables it to be mounted in a variety of ways, including: directly to the top of a machine tool, on a stand, or suspended from a factory ceiling. Maintenance and operating costs of the Royal Filtermist are minimal.

The low-cost Royal Filtermist effectively collects mist and smoke generated by all types of machines including:

  • CNC Lathes
  • CNC Machining Centers
  • All Types of Grinders
  • Manual Lathes
  • Milling Machines
  • Swiss-Style Machines
  • Multi-Spindle Automatics
  • Injection Molding Machines
  • Some Heat Treating Processes
  • Rotary Transfer Machines
  • Gear Hobbers
  • Cold Heading Machines
  • Aqueous Parts Washers
  • Vacuum Pumps
  • Printing Presses
  • Confectionary Machinery

Additional Information:

How Does The Royal Filtermist Work?

The Royal Filtermist uses the principle of centrifugal impaction to eliminate mist. With only three main components: a drum, a motor, and the housing, its operation is quite simple.

  1. A three-phase motor rotates the internal drum at high speed, creating a vacuum which draws mist particles into the center of the drum.
  2. The mist particles then collide with the rotating drum’s vanes and are forced together with other particles, causing them to coalesce and form larger, droplet-sized particles.
  3. As the particles grow into droplets, they pass through the perforations in the rotating drum and centrifugal force causes them to be thrown onto the inner wall of the housing.
  4. The particles are then forced, under pressure, up the walls of the housing to the oil return channel, where they are subsequently drained back to the machine’s coolant tank.
  5. Clean, oil-free air blows past the motor and is returned to the shop.
  6. Since this process relies on the mechanical principle of centrifugal impaction and the rotational speed remains constant, the Royal Filtermist maintains a continuous high efficiency.
  7. For certain applications that produce smoke and/or very fine mist particles, an after filter may be required. This filter easily mounts to the top of the Filtermist unit by slipping over the motor and it is secured in place with two toggle clips. An after filter mounted to a Royal Filtermist typically enjoys a comparably long service life because most contaminants are removed by the impaction process prior to reaching the filter.
Note – it is important to understand that the pads that line the Filtermist drum are not filters. These porous pads are present to slow airflow through the unit, thereby maximizing contact with the drum vanes for greatest overall impaction efficiency.
Design Features
Royal Filtermist Inner View
  • Compact design and reduced weight provide greater mounting flexibility.
  • Oil return channel has been enlarged, enabling unit to process a greater volume of liquid.
  • Gap between drum and housing has been optimized for maximum filtration efficiency.
  • Conical air deflector positioned at intake accurately controls airflow within unit.
  • Heavy-duty 3-phase motor meets all federal, state, and local electrical and safety codes.
  • Exceptional vibration control through dynamic balancing, uniform mass distribution, and neoprene isolators separating the motor/drum assembly from the housing.
  • Curved drum vanes improve airflow.
  • Air flow is automatically regulated as machine doors close to keep the correct negative pressure inside the enclosure. No need to adjust drum speed.

The three-phase Filtermist motor must be wired in conjunction with a manual starter, which is not supplied by Royal Products. The recommended heater size is 1.25 times the rated motor amperage, based upon your plant’s operating voltage. We suggest you have a licensed electrician perform the wiring of the unit. Detailed instructions can be found in the installation manual that is supplied with each unit. As an option, Royal offers a complete starter box kit which includes all of the necessary hardware and wiring.

Intake Position — Very Important
Royal Filtermist Intake Position

When installing a Filtermist unit, be sure to locate the intake in a position where it will collect mist, not splash. A common mistake is to locate the collection point too close to the cutting action, causing raw coolant and chips to be drawn into the unit. For example, the intake on a CNC lathe should be located near the tailstock-end of the machine, not over the chuck. Whenever possible, draw the mist across the enclosure from an area of heavy concentration to an area of lighter concentration.

For machines where the intake must be positioned near the cutting action, a deflector is often necessary. A deflector protects the intake from chips and coolant yet allows mist and smoke to pass around it for collection.


When evaluating the effectiveness of any mist collection system, two major aspects must be considered:

  • The unit must be capable of handling the full volume of mist produced by the application.
  • The unit must be efficient at capturing particles of all sizes.

Independent testing has proven the Royal Filtermist FX Series to be very effective at handling large volumes of mist and highly efficient at dealing with the full spectrum of particle sizes found in typical metalworking mist concentrations.

While a typical metalworking mist concentration is made up of many different-sized particles, 80–90% of these particles are larger than one micron in size. Fewer than 10% of the particles are smaller than 0.5 micron in size.

In order to effectively eliminate mist, the Royal Filtermist incorporates a two-phase process:

  1. The first phase utilizes the mechanical process of centrifugal impaction. This centrifugal impaction process is the heart of the Filtermist’s operating principle and it is highly effective at handling large volumes of mist.

    The centrifugal impaction process is almost 100% efficient at handling particles larger than one micron, which make up the bulk of the mist. When considering a weighted average of the particle size in a typical metalworking mist concentration, overall efficiency of the impaction process is roughly 98%.

  2. Many may consider an efficiency of 98% to be adequate for their needs. However, if additional efficiency is required, the Royal Filtermist FX Series units may be equipped with an after filter to handle the small amount of residual mist that bypasses the impaction process. Royal after filters use a carefully selected grade of media that provides an effective balance between being fine enough to capture the smallest of particles while still allowing the filter to enjoy a comparatively long service life. Overall efficiency of a Royal Filtermist FX Series unit equipped with an after filter exceeds 99.5%.

IMPORTANT — An after filter should not be used to compensate for blow-thru that could result from improper installation. If you have questions or concerns about your installation, please contact us.

OSHA and NIOSH Standards

The OSHA and NIOSH limits on airborne mist particles are currently set at 5mg/m3. It is believed that in the coming years this level will be reduced by a factor of ten to a new level of 0.5 mg/m3. The Royal Filtermist FX is so efficient that when equipped with an after filter, it easily meets not only the current limit, but even the stricter proposed limit.

In a recent test carried out by an independent contractor, a Mori Seiki SL75ML was fitted with a model FX-1200 Filtermist unit and after filter. Particle counters were set up to monitor the air at three locations during machining — the ambient shop air, the Filtermist intake, and the Filtermist exhaust. The test results confirm that the Filtermist easily meets the challenge. Particle concentration levels at the Filtermist exhaust were well below 0.5 mg/m3. In fact, the air at the Filtermist exhaust was four-times cleaner than the ambient shop air!

Ambient Shop Air 0.75
FX-1200 Inlet 8.0 - 10.0
FX-1200 Exhaust 0.18

IMPORTANT — The Royal Filtermist is designed to help your shop meet current and future air quality standards. It must be understood, however, that there are many variables involved in controlling shop pollution and we cannot guarantee that the Filtermist alone will prevent occupational diseases to workers. It is your responsibility to establish an effective overall industrial hygiene program designed to comply with OSHA and NIOSH standards.

Risk-Free Performance Guarantee

Royal Products will issue full credit on any Royal Filtermist unit returned within 45 days of the purchase date if the customer is not completely satisfied with its performance.
The following conditions apply:

  1. The unit must be sized and installed according to our recommendations.
  2. Credit will be issued for the unit, but may not be issued for ductwork, oil return hoses, etc., if they are not in resalable condition.
  3. The customer must contact us for a return goods number (RGA #). This number must appear on all paperwork and packaging of the unit being returned.
  4. The returned unit must be securely packaged and arrive at Royal Products in good condition.