

The principle of impaction can be easily understood by considering a car passing through a fog bank. As the fog hits the windshield, tiny mist particles begin to grow into water droplets which are then shed off.
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.
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.
The Royal Filtermist FX Series is the ninth generation of Filtermist. FX Models incorporate a number of design improvements over previous versions to provide the most advanced and effective system available for the removal of mist and smoke.


The Royal Filtermist is available in four sizes, based on throughput capacities: 300, 575, 900, and 1200 cfm. Royal Products maintains a database with specifications for many different machine tools, and we recommend you contact one of our applications engineers for your specific sizing requirements. For those who would like a general rule of thumb, we recommend using the following formula to obtain a rough idea of your requirements:
Filtermist Size = Internal Enclosure Volume x 5
For example, suppose you have a small CNC lathe with an internal work envelope measuring 5ft. wide x 3ft. deep x 4ft. high. Multiplying 5x3x4, we see that the machine has an enclosure volume of 60 cu. ft. Multiplying 60×5 we see that 300 cfm is required, so we’d choose the model FX-300.
Although this rule is very simple, it is handy for determining the general size requirements.
If you are not sure which unit to use, please contact your local Royal Filtermist Distributor or one of our applications engineers.

Grinding applications can sometimes be more demanding than typical turning and milling applications because grinding produces fine dust particles that become entrained in the mist stream. Over time, this dust can accumulate on the drum pads, resulting in the need for more frequent maintenance. If regular maintenance is not performed and a significant volume of solid matter builds up in the drum, balance and vibration issues may arise.
A simple way to overcome the problems associated with grinding dust is to fit the Filtermist with a cyclonic swarf separator. The separator mounts below the Filtermist unit and uses cyclonic action to separate out the solid matter, leaving the drum free to process the mist and preventing buildup on the pads. A port on the bottom of the unit facilitates drainage.
Royal Products recommends using a cyclonic swarf separator for all grinding applications.

CNC lathes are relatively easy applications to tackle because the machines are usually well enclosed and direct mounting is often possible. On any well enclosed machine, it is recommended that the Filtermist intake point be located as far from the machining action as possible so that the mist is drawn from an area of heavy concentration to an area of lighter concentration. On CNC lathes, therefore, the ideal intake location is on the right side of the machine, near the tailstock. On subspindle lathes where the right-hand wall moves along the z-axis, it might be necessary for the Filtermist to have a more central location.

For enclosed machining centers, the Filtermist intake position should be located in an upper corner of the enclosure. Installation on open-top machines is not as clear-cut. If enclosing the machine is not possible, a successful installation can often be accomplished by suspending the Filtermist unit above the machine and running ducting down into the enclosure. It may be necessary to adjust the intake location so that it is close enough to the spindle to collect the mist, yet far enough away to keep chips from being drawn in. A Y-junction may be used to draw mist from both sides of the spindle, and a chip deflector may also come in handy.

More and more machine tools today are equipped with high-pressure coolant systems. Machines running either oil or coolant at high-pressure tend to create a greater volume of mist, with a smaller average particle size. For high-pressure applications, equipping your Filtermist unit with one (or both) of the performance accessories below will greatly help to optimize mist control within your shop.

This after filter has been specifically engineered for high-pressure coolant and oil applications. Laboratory and field performance tests have shown the service life to be as great as 10x that of a standard after filter.

While this accessory was originally designed to remove solid particulate entrained in the mist steam, it has also proven to be very effective as a pre-filter in high-pressure applications by removing much of the mist prior to the impaction process.
Risk-Free Performance Guarantee 
Royal’s exclusive Risk-Free Performance Guarantee enables customers to try a Quick-Grip™ or Filtermist on the toughest jobs in their shop for 45-days, and if they are not 100% satisfied with the performance, Royal will take it back and arrange for a full refund.
The following conditions apply:





In order to fully understand why the Royal Filtermist is the best choice for handling oil mist and smoke produced by the metalworking industry, it is important to have some general knowledge of how other types of collection systems work. This section contains an overview of the most common methods for controlling mist and smoke. While these systems all have some positive features, their drawbacks make them unsuitable for use in most metalworking applications.
At one time, the only method for controlling oil mist and smoke in a shop was to vent it out of the building. This was done either by opening the doors and windows or installing a ventilation system. While this method may look like an attractive low-cost solution, the potential dangers should be enough to make any shop owner reconsider this practice.
Environmental Hazards Today, it is illegal in many states to exhaust pollutants to the atmosphere. Offending companies run the risk of large fines and lawsuits.
Fire Hazards Over time, oil deposits collect in the ductwork of ventilation systems, making them prime targets for flash fires and providing pathways for fires to spread quickly.
Cleanliness Problems As mist and smoke travels through a shop to the exhaust points, it collects on exposed surfaces. Over time, a grimy buildup occurs on machines, lights, floors, and walls, resulting in dirty, unsafe conditions.
Media-type filtration systems typically consist of a blower and several filters of varying efficiencies. The contaminated air first passes through a coarse pre-filter where the largest particles are filtered out. It then moves through one or two medium-range filters before reaching the final filter, which is usually made from a high-efficiency HEPA material. Media-type systems are good at collecting dry contaminants such as welding smoke and graphite dust. However, they are often not suitable for metalworking applications where coolant mist is the primary contaminant.
High Operating Costs The biggest drawback of media-type filtration systems is the high operating cost associated with replacement filters. These filters are designed to retain contaminants, so they will become clogged with use. Usually they are made from media that cannot be cleaned, so the only alternative is replacement. Depending upon the cost of the filters and the replacement frequency, this type of system can be quite expensive to operate over the long term.
Decreased Throughput Another problem with multi-stage filter units is that the throughput of the system, measured in cfm, decreases as contaminants become trapped in the pores of the filters. It is important to maintain the correct throughput of any collection system. Reduced throughput means reduced collection, allowing contaminants to escape into the shop air.
Not for Mist Most media filters are designed to collect dry pollutants such as smoke and dust. Exposure to coolant and oil mist may damage certain types of filter media.
Electrostatic precipitators use a blower to draw mist and smoke particles past an ionizer, which imparts a positive charge to them. They then pass across a series of alternately like-charged and grounded collection plates. The particles are repelled by the like-charged plates and forced towards the grounded plates where they collect. The filtered air is returned to the shop.
Variable Efficiency Although electrostatic systems are very efficient when the collection plates are clean, the efficiency drops off drastically as the plates become covered with particles. Each time a particle deposits on a plate, it eliminates a spot for other particles to adhere to.
Maintenance Costs To maintain high efficiency, the collection plates must be cleaned often. This can be expensive because the residue is considered to be hazardous waste and must be disposed of by a certified waste handling company. Many electrostatic systems are sold with costly maintenance contracts, resulting in operating costs that greatly exceed the original unit purchase price.
Health Hazards As the collection plates become full, a phenomenon known as arcing can occur. This arcing results in the production of ozone, which has been found to cause a variety of health problems. This potential danger (and the fear of lawsuits) has caused many U.S. companies to remove electrostatic units from their factories.
Ozone produced by electrostatic precipitators has been identified as a health risk to humans. Several U.S. government agencies have weighed-in on ozone as it relates to indoor air quality:
According to the Environmental Protection Agency (EPA): When inhaled, ozone can damage the lungs. Relatively low amounts can cause chest pain, coughing, shortness of breath and throat irritation. Ozone may also worsen chronic respiratory diseases such as asthma and compromise the ability of the body to fight respiratory infections. People vary widely in their susceptibility to ozone. Healthy people, as well as those with respiratory difficulty, can experience breathing problems when exposed to ozone.
Current U.S. guidelines on indoor ozone levels:

After filters are available for all Royal Filtermist models. They can be used in any application where extreme high efficiency is required, and are especially useful for dealing with the following conditions:
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.
Easy Installation
The Royal standard after filter simply slides over the Filtermist motor and is secured in place with two toggle clips.
High Efficiency
Adding a standard after filter to a Royal Filtermist unit will greatly increase efficiency in the sub-micron range.
Noise Reduction
An after filter reduces the noise level of a Filtermist unit by approximately 3 dB.
Long Life
Royal standard after filters have extended service lives due to their large surface area. They also last longer because the centrifugal impaction process of the Filtermist removes most of the pollutants before they ever reach the filter. Systems that rely entirely on media filters for the filtering process tend to have much shorter service lives.
Full Range
Standard after filters are available for all size Filtermist units. Models are also available for older series units.
For very demanding applications, Royal now offers an optimized high-performance after filter.


| MODEL | A | B | C |
|---|---|---|---|
| 30220 (FX-900 & 1200) | 6″ | 9 1⁄2″ | 10″ |
| 30222 (FX-300 & 575) | 4 3⁄4″ | 8 1⁄2″ | 8 1⁄2″ |

A wide variety of mounting options makes the Royal Filtermist very easy to install on virtually any machine tool.
All brackets, stands, and mounting accessories may be ordered individually for your particular application, or you can enjoy the ease of single part number ordering with our universal Easy-Mount™ packages.
For all mounting questions, please contact one of our applications engineers at 1-800-645-4174.
| FX-300 | FX-575 | FX-900 | FX-1200 | |
|---|---|---|---|---|
| Floor Stand | YES | YES | YES | YES |
| Machine Top Stand | YES | YES | YES | YES |
| Wall Mount | YES | YES | YES | YES |
| Side Mount | YES | YES | NO | NO |
| Plenum | YES | YES | YES | YES |

Useful for open-top machine tools such as vertical machining centers where there is no option for mounting the mist collector on top of the machine.
The floor stand for models FX-900 and 1200 is adjustable from 6-9ft.
The floor stand for models FX-300 and 575 is fixed at 6ft.
Note – all floor stands must be bolted to the factory floor to prevent tipping.


Wall mount brackets are available for all models. These brackets can be mounted to walls or I-beams, and can also be used to mount the mist collector to the side of the machine tool as shown.


A great option when you want the mist collector off the floor, but your machine doesn’t lend itself to direct mounting because the ideal intake location within the machine enclosure is not compatible with the mist collector positioning.
The machine top stand for models FX-900 and 1200 has a fixed height of 36″.
Two height options are available for models FX-300 and 575: 28″ and 10.5″.


The side mount bracket is specifically designed for models FX-300 and 575. It mounts directly to the side of the machine tool with no ducting required.
Bracket includes an integral chip deflector. Provides a very clean installation on most smaller CNC machine tools.


With its side-located intake, Royal’s new plenum offers the flexibility for machine top mounting in applications where the mist collector location and intake point are not compatible. Available for all models.


No matter what type of machine you are installing your Royal Filtermist on, it is very important to always 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.
Whenever possible, draw the mist across the machine 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 can be used to protect the intake from chips and coolant while allowing the mist to pass around it for collection.
The Royal Filtermist is available in four sizes, based on throughput capacities: 300, 575, 900, and 1200 cfm. Royal Products maintains a database with specifications for many different machine tools, and we recommend you contact one of our applications engineers for your specific sizing requirements.
For those who would like a general rule of thumb, we recommend using the following formula to obtain a rough idea of your requirements:
Filtermist Size = Internal Enclosure Volume x 5
For example, suppose you have a small CNC lathe with an internal work envelope measuring 5ft. wide x 3ft. deep x 4ft. high. Multiplying 5x3x4, we see that the machine has an enclosure volume of 60 cu. ft. Multiplying 60×5 we see that 300 cfm is required, so we’d choose the model FX-300.
Although this rule is very simple, it is handy for determining the general size requirements.
If you are not sure which unit to use, please contact us to arrange for a visit from one of our local factory trained representatives or to speak with one of our applications engineers about your specific application.

Grinding applications can sometimes be more demanding than typical turning and milling applications because grinding produces fine dust particles that become entrained in the mist stream. Over time, this dust can accumulate on the drum pads, resulting in the need for more frequent maintenance. If regular maintenance is not performed and a significant volume of solid matter builds up in the drum, balance and vibration issues may arise.
A simple way to overcome the problems associated with grinding dust is to fit the Filtermist with a cyclonic swarf separator. The separator mounts below the Filtermist unit and uses cyclonic action to separate out the solid matter, leaving the drum free to process the mist and preventing buildup on the pads. A port on the bottom of the unit facilitates drainage.
Royal Products recommends using a cyclonic swarf separator for all grinding applications.


For enclosed machining centers, the Filtermist intake position should be located in an upper corner of the enclosure. Installation on open-top machines is not as clear-cut. If enclosing the machine is not possible, a successful installation can often be accomplished by mounting the Filtermist unit above the machine and running ducting down into the enclosure. It may be necessary to adjust the intake location so that it is close enough to the spindle to collect the mist, yet far enough away to keep chips from being drawn in. A Y-junction may be used to draw mist from both sides of the spindle, and a chip deflector may also come in handy.
More and more machine tools today are equipped with high-pressure coolant systems. Machines running either oil or coolant at high-pressure tend to create a greater volume of mist, with a smaller average particle size. For high-pressure applications, equipping your Filtermist unit with one (or both) of the performance accessories below will greatly help to optimize mist control within your shop.

This after filter has been specifically engineered for high-pressure coolant and oil applications. Laboratory and field performance tests have shown the service life to be as great as 10x that of a standard after filter.

While this accessory was originally designed to remove solid particulate entrained in the mist steam, it has also proven to be very effective as a pre-filter in high-pressure applications by removing much of the mist prior to the impaction process.
If you have any questions regarding the use of these performance accessories in your high-pressure applications, please contact us to schedule a visit by one of our factory-trained mist control experts.
When evaluating the effectiveness of any mist collection system, two major aspects must be considered:
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, usually 80 – 90% of these particles are larger than one micron in size, and 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:
The OSHA and NIOSH limits on airborne mist particles are currently set at 5 mg / 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.
| LOCATION | CONCENTRATION (mg / m3) |
|---|---|
| Ambient Shop Air | 0.75 |
| FX-1200 Inlet | 8.0 – 10.0 |
| FX-1200 Exhaust | 0.18 |
Basic sizing information can be found above in “Choosing the Right Filtermist Unit”. You are always welcome to speak to one of our engineers if you have any questions. We can also arrange to have one of our local regional managers visit your factory to check out your application and make the appropriate recommendations.

The Royal Filtermist is a relatively easy piece of equipment to install, and most shops handle their own installations. Detailed instructions are included with each unit.
To ensure a smooth installation process, be sure you have ordered all of the necessary mounting and performance accessories. Please note that all accessories offered in this catalog have been tested for performance and safety. Substituting accessories with non-Royal items could void the Filtermist warranty, affect performance, and result in dangerous operating conditions.
The three-phase Filtermist motor must be wired in conjunction with a motor starter switch, which can be purchased through Royal Products. 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.

An important aspect to understand about the Royal Filtermist is that the drum pads 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.
Because the Royal Filtermist utilizes the mechanical process of centrifugal impaction to eliminate mist, maintenance requirements are minimal. As a result, some customers have reported that they have had units operating for up to five years without ever needing to change the drum pads.
