When properly designed and operated, water in the form of mist or fog is extremely effective at ‘filtering’ the air. One study even showed where a mist system could substantially reduce the amount of CO2 in the air. So the concept is not limited to dust particles. it can also remove airborne odors and gases.

Traditionally, this method of dust control worked best in an indoor environment where conditions allowed for the installation of a typical overhead mist system. It was not always practical to install such a system in a facility where the dust control requirement was outdoors in an open area.

For these types of applications (which include waste treatment facilities, rock crushing, mining, waste transfer, recycling, construction sites, and structure demolition) a more specialized solution was required. The solution is Spraystream.

Spraystream can best be described as a ‘fog cannon’. The product produces a high velocity column of air that travels up to 150 feet away from the unit. Introducing a concentrated stream of mist within the column of air provides dust and odor control capability over an extremely large area. The cannon includes vertical adjustment of the air stream and can also be equipped with an automated oscillator allowing for dust control coverage of up to 70,000 square feet. The video of the Spraystream products in use shows the versatility and capabilities of this product. It is ideal for outdoor use and provides access to advanced technology that efficiently and effectively suppresses dust and odor in commercial and industrial applications.

The products are engineered for industrial use in the most extreme environments. They include a variety of sizes and options including wall mount units, portable cart units, and completely self contained trailer units.

The specification pages for the Spraystream products can be found on the Fogco Downloads page of our website.

A direct drive misting pump will usually be the least expensive (except in some cases with sizes above 3gpm) but will also be the loudest because the motor and pump will both be spinning at full rpm (1750 for our standard 60 Hz 4 pole motors and 1450 for our standard 50Hz 4 pole motors).

A pulley drive is typically more expensive than a direct drive because it includes 2 pulleys, a belt and requires either an enclosure or a belt guard. Also, a pulley drive misting pump will include an oversized bare pump (our standard 1 gpm pump utilizes a 3.8 gpm bare pump) so that we can slow down the rpm of the pump and still achieve the necessary flow.

Most Fogco pulley drive misting pumps also include additional components compared to a direct drive unit (which contributes to its higher cost basis) to add function and feature to the puleey drive pump design. We use a full enclosure (except in our table top designs which already include a separate control box) because it provides a place for us to include various custom electrical components without having to provide a separate control box and it eliminates the need for the belt guard.

Even though the motor in a pulley drive unit will turn at full rpm, it will always be quieter than a comparably sized direct drive pump because the pump is turning at a slower rpm than the motor and creates less vibration and less mechanical noise. The pulley drive misting pump also produces less noise because it is typically fully enclosed where the direct drive pump typically is not.

A Variable Frequency Drive mist pump is the most expensive option but it does have some unique and valuable characteristics. First, it consumes between 20% and 25% less electricity to operate a VFD system than a non-vfd system due to the inclusion of the VFD inverter and the way it utilizes electricity. This is only the first of three electricity related efficiencies associated with a vfd mist pump pump but it is the primary reason vfd units are desired for many commercial and industrial applications.

Because of the inclusion of a pressure transducer in the Fogco VFD misting pump, the system also provides the unique capability of only turning the motor at the required hertz based on the flow demand at any given time. This unique feature provides a variable operating speed for the motor. In most cases, the motor AND the pump are both spinning at an rpm level that is less (usually much less) than a standard direct drive or pulley drive unit. The result is not only a substantially quieter operating mist pump, but a mist pump that requires less electricity to operate. This is the second of three electricity related efficiencies associated with a vfd misting pump.

As an example, if a 2 gpm system utilized a direct drive pump, both the pump and motor would turn at 1750 rpm. A pulley drive unit would require the motor to turn at 1750 rpm but the pump would only turn at about 920 rpm (using a bare pump that provides 3.8 gpm at 1750 rpm). A vfd unit would allow the motor AND the pump to both turn at 920 rpm (using a bare pump rated at 3.8 gpm at 1750 rpm). The result of this is the direct drive would be the loudest; the pulley drive would be quieter than the direct drive; the vfd would be significantly quieter than the pulley drive. This scenario and explanation does not take into considerations other on site conditions that may affect the noise levels but it is a good standard to measure when considering the noise levels associated with a direct drive, a pulley drive, or a vfd mist pump system.

As system flow requirements increase, the VFD will progressively increase the speed of the motor until the pump is providing the required flow to achieve the required 1000 psi pressure. As this motor speed increases, it will increase the noise level and it is possible that if the motor and pump are required to spin at full hertz and rpm (60 and 1750 respectively) due to the maximum flow requirement for the system, the noise level for the vfd in that scenario could be equivalent to the noise level of a direct drive or pulley drive unit of comparable size. However, bucasue the vfd unit affects the spped of the motor being used, it is always possible to versize the vfd unit so that it never spins above a desired rpm.

Other than the power consumption savings on commercial or industrial systems and not accounting for any noise level considerations, a vfd is most typically used when the system includes multiple zones but flow for the system at any given time is less than 50% (and may as low as 5%) of the pumps capacity. In these cases, the vfd has the ability to manipulate the power supply to the motor and thereby affect the motor rpm such that the pumps resulting flow output exactly matches the systems requirements at that point in time.

That means there is no bypass in the system (since there is no excess water being pressurized and bypassed, there is no heat build up in the water supply for the pump so damage to the internal components of the pump is eliminated) which means the system operates more efficiently because the pump is not over working itself by producing excess pressurized water. This is the third of three electricity related efficiencies associated with a vfd pump.

So, there are three options available for mist pump design and each has its own characteristics that make it appropriate for a given project. The most appropriate option should be determined based on the needs and desires of the end user.

Why so many misting nozzles?

Misting nozzles come in a variety of shapes and sizes. It is often asked,’Why so many and what are the differences?’. The purpose of this blog is to answer these questions and define the performance capabilities of the impeller misting nozzles offered by Fogco.

Impingement versus Impellar

There are two basic types of misting nozzles, impingement nozzles and impellar nozzles. Impingement nozzles allow water to exit the nozzle in a straight stream through a very small orifice (typically .008″ or about 200μ or microns) and immediately collide with a solid pin which effectively atomizes the water into tiny droplets, usually between 1μ and 15μ. Impingement nozzles tend to be very expensive; it is hard to maintain the position of the solid pin and therefore hard to maintain their performance; and they are typically used in speciality applications. For these reasons, they will not be further defined in this blog post. For more information on impingement nozzles, contact Fogco Customer Service.

Impellar nozzles are the most common misting nozzle and they have been used in the mist and fog industry for over 50 years. They are much less expensive than impingement nozzles and they are more reliable. The downside of this mist nozzle design is that it cannot consistently produce as fine a droplet as an impingement nozzle. For the vast majority of applications, this is not an issue which is the primary reason why impellar nozzles are so widely used. A well designed and machined impellar style nozzle will provide droplets ranging from a few microns up to about 50μ with the majority of the droplets being larger than 10μ.

Although there have been improvements to impellar misting nozzles over the last 20 years, the basic performance and function has not changed. Essentially, the impellar style nozzles are designed to atomize the water flow into tiny droplets. These nozzles utilize a barrel shaped impellar, a small orifice, and a vortex shaped interior to force the water through the nozzle in such a way that it explodes through the small opening in a circular motion resulting in billions of tiny individual droplets.

When placed in a series along a length of tubing or onto the facing of a fan, the water is absorbed by the air and evaporative cooling takes place. If the nozzles are placed in an enclosed area, increased humidity levels are achieved. These nozzles are available in brass and stainless steel or in an all stainless steel design. They are also available with standard orifice sizes from .006″/.015mm to .020″/.5mm. Larger orifice sizes are also available as special order.

Standard mist nozzles versus Cleanable mist nozzles

There are two basic types of impellar nozzles, cleanable and non-cleanable. The cleanable mist nozzle refers to a nozzle design that allows the barrel shaped impellar to be removed from the body of the nozzle allowing for the easy removal of foreign debris as well as the ability for cleaning solution to flush the interor of the nozzle and remove any dissolved solids that may plug up the orifice. In 95% of the cases, a poor spraying or plugged nozzle can be dis-assembled and cleaned returning the nozzle to its original performance capability.

The cleanable nozzles also include an anti drip assembly inserted into the body of the nozzle. This assembly prevents the misting nozzle from dripping each time the system is turned off. In some applications this is not that important, but if preventing the nozzle from dripping is important, the anti drip assembly is crucial. The anti drip assembly can be removed from the nozzle if it is not required.

The standard non-cleanable nozzles are less expensive but they cannot be as readily cleaned as the cleanable design. The success rate for improving a plugged or poor spraying non-cleanable nozzle is about 50%. In most cases, the overall investment of the entire misting system justifies the extra cost of the cleanable nozzles. They usually pay for themselves within the first year.

The Nozzle Page and the Fogco Product Catalog provide specific information on the available misting nozzles, but the additional details below may be helpful in deciding which orifice size is best for a specific applicaton.

The .006″/.15mm nozzle (YELLOW o-ring) is the smallest standard nozzle orifice available. At 1,000 psi, the mean diameter of the droplets from this size orifice are 12.2μ with droplets ranging from 1.2μ to 36.4μ with a spray diameter of approximately 45 degrees. The .006″/.15mm misting nozzle is ideal for applications requiring extremely low flow with small droplet size and minimal moisture. It is most commonly used for humidification applications. This nozzle is not designed to be used at pressures below 500 psi.

The .008″/.20mm nozzle (RED o-ring) is the next smallest standard nozzle orifice available. At 1,000 psi, the mean diameter of the droplets from this size orifice are 12.7μ with droplets ranging from 1.4μ to 37.9μ with a spray diameter of between 60 degrees and 65 degrees. The .008″/.20mm misting nozzle is ideal for applications requiring low flow with small droplet size and limited moisture. It is most commonly used for humidification and cooling applications. This nozzle is not designed to be used at pressures below 250 psi.

The .012″/.30mm nozzle (BLACK o-ring) is the medium sized standard nozzle orifice. At 1,000 psi, the mean diameter of the droplets from this size orifice are 13.1μ with droplets ranging from 1.6μ to 39.1μ with a spray diameter of between 65 degrees and 75 degrees. The .012″/.30mm misting nozzle is ideal for applications requiring moderate flow with small droplet size. It has a similar performance to the .008″/.20mm orifice nozzle with an increased flow rate. It is most commonly used for outdoor cooling odor/dust control applications. This nozzle can be used with any pressures above 100 psi.

The .016″/.40mm nozzle (BROWN o-ring) is a larger sized nozzle orifice. At 1,000 psi, the mean diameter of the droplets from this size orifice are 14.8μ with droplets ranging from 3.8μ to 47.9μ with a spray diameter of between 70 degrees and 80 degrees. The .016″/.40mm misting nozzle is ideal for applications requiring increased flow rates with moderately sized droplets. It is most commonly used for special effects and outdoor dust control applications. This nozzle can be used with any pressure.

The .020″/.50mm nozzle (GREEN o-ring) is a largest sized standard nozzle orifice. At 1,000 psi, the mean diameter of the droplets from this size orifice are 15.2μ with droplets ranging from 9.5μ to 49.9μ with a spray diameter of between 80 degrees and 90 degrees. The .020″/.50mm misting nozzle is ideal for applications requiring extreme flow with larger droplets where complete evaporation is not required. It is most commonly used for outdoor dust control in demolition applications. This nozzle can be used with any pressure.

Now that we are ending the summer season and heading into fall, temperatures are dropping and the use of a misting system as an outdoor cooling system is drawing to a close until next summer. To help maintain the integrity of the system and to prevent unnecessary damage, it is a good idea to winterize the system and the misting pump before temperatures drop below freezing.

Winterizing a misting system is essentially about removing any excess water and any restrictions that may cause freezing water to damage the various components of the pump and tubing. To accomplish this, the following steps should be taken:

1. Turn off the water supply to the mist pump
2. Remove the inlet and outlet tubing from the mist pump
3. Remove the thermal relief valve from the mist pump plumbing
4. Disconnect the bypass hose from the bottom barb fitting on the mist pumps inlet plumbing
5. Turn on the mist pump. If a low water safety switch is not included on the pump build, the motor will run and will sufficiently empty the bare pump of any excess water within a few seconds. If the pump has a low water safety switch. the motor will not run because the water supply has been turned off. The inlet solenoid valve, however, will be open and will allow the bare pump to be purged of any excess water by forcing compressed air into the pumps inlet and outlet ports until no water exists the pump. This should only take a few seconds. If no compressed air is available, rotate the pulleys on a pulley drive pump or rotate the fan on the rear of the motor on a direct drive pump. Either of these steps will allow excess water to be removed from the bare pump.
6. Turn the mist pump off.
7. Remove the mist nozzles and drain valve(s) from the mist line.
8. Using compressed air, blow out the mist lines until no water exists any open ports. Store the nozzles and drain valve(s) in a dry location until the next season. Soaking the nozzles in heated nozzle cleaner before reinstalling will usually provide improved performance from the misting nozzles.
9. Disconnect the water supply from the filter canister and completely empty the canister. Use compressed air and blow out the feed line between the filter and the mist pump.

This process is a little time consuming but will ensure that no damage is done to the misting pump or the mist tubing during the winter months. At the start of the next summer season, simply connect all the tubing, insert the nozzles, and start enjoying the cooling effects of your misting system for another summer season.

High pressure misting systems, sometimes referred to as fog systems, have quietly become one of the most effective and economically viable means of dust and odor control.

Although the concept is still unknown to many in the dust control industry, misting systems have proven themselves to be an effective means of dust suppression, dust abatement, and open air filtration. A properly designed and installed misting system can suppress and remove breathable fugitive dust particles as small as 1 micron in diameter and easily exceeds the EPA PM 10 standards for dust suppression.

This approach has been widely accepted in solid waste treatment facilities as the best alternative to remove and suppress airborne dust. It is not unusual for architects to include the installation of a dust control misting system in the original specifications for a newly commissioned facility. In addition, many existing plants are retrofitting their building with these efficient means of dust control.

In the same way, an effective dust control system can also be and effective odor control system. The only difference is the inclusion of an injection system that will introduce a variety of chemicals into the environment that are used to efficiently cover or even digest the very cause of the odor. This would include odor control problems such as microbial decomposition (commonly found in solid waste treatment facilities), animal waste (as found in poultry, hog, and cattle producing facilities) and other noxious volatile compounds (including restaurant grease traps).

Premium Series Misting pumps

A high pressure misting system can be an efficient and economical delivery system for both dust and odor removal requirements and are less expensive and require less maintenance than other more traditional means including air injection. In addition, by incorporating different components for system control, the entire process can be automated.

Facilities that can benefit from the effective and efficient means of dust and odor control include solid waste transfer stations, construction sites, landfills, composting facilities, poultry and livestock facilities, and food processing plants.

As recap, a properly designed and installed high pressure misting system can be the most effective means of odor and dust control; it is generally less expensive to operate and maintain than other methods; it can eliminate hazardous working conditions while improving the overall environment for people and animals; and it can remove breathable fugitive dust particles down to 10 microns or below.

Outdoor cooling is not a new phenomenon. It has been used for decades to keep animals cool where air conditioning simply was not practical. The most common uses for a typical misting system going back to the 1950′s included outdoor cooling for poultry and cattle.

Misting Systems Coming of Age

In the 1980′s, after years of proven performance and with continued emphasis on product improvements, outdoor misting systems were perfected enough to apply their cooling capabilities to outdoor areas for people. These unique systems began to show up on restaurant patios in places like Phoenix and Palm Desert where the climates were hot and dry for up to 8 months out of the year.

Throughout the 1990′s, this new method of effective outdoor cooling continued to gain momentum and was soon economically viable for residential use. The cost for the systems was less than 1/2 of what it was in the mid 1980′s and even a modest home could justify the expense, especially considering the cooling capability (lowering outdoor temperatures by as much as 25 degrees) and the fact that this method of outdoor cooling allowed the patio or gazebo to be used even during the hottest summer months.

Today, mist systems are seen at hotels, restaurants, theme parks, universities, and almost any outdoor environment where temperatures exceed 90 degrees. Due to constant improvements in mist system design and mist system nozzles, these relatively new means of outdoor cooling are even used effectively in humid climates throughout the South and Mid-Western United States where temperature reductions of between 10 degrees and 15 degrees are achievable.

Fogco is pleased to introduce a new range of misting nozzles. Besides the standard nozzles which have been offered for over 2 decades with a proven performance record, we now provide an upgraded option to the nozzle range called Cleanable Nozzle. This mist nozzle is designed to be completely taken apart to gain access to the nozzle interior thereby allowing for removal of small debris as well as calcium or dissolved solids build up.

With the traditional misting nozzle, removing obstructions from the interior was difficult at best, and only successful in improving the nozzle performance about 50% of the time. This meant that once the nozzles spray pattern was distorted, the nozzle usually had to be discarded and replaced.

Cleanable Mist Nozzles

With the new cleanable mist nozzle, the internal impellar can be removed and the body can be easily cleaned or blown out using compressed air and usually results in improving the nozzles spray pattern over 955 of the time. In most cases, the nozzle spray pattern is returned to its original performance.

In addition, this new range of misting nozzles includes the anti-drip body and assembly which eliminates the need to buy these components (as is required to upgrade the standard nozzle). The Cleanable Nozzle range comes standard in sizes from .006″ to .020″ and is available in larger sizes on a custom order basis. The Cleanable Nozzles are available in Brass/Stainless Steel or all Stainless Steel.

As with most pieces of equipment, the most important factor in extended life is proper maintenance.  This is one thing that is the total responsibility of the mist system installer or the end user.  The recommended maintenance includes an annual review of the misting pump and all of its working components.  This can be done by the end user, the contractor who installed the system, or by Fogco at its facility.

The most critical ongoing maintenance items that should be closely watched by the end user or whoever is providing the maintenance to the misting pump  include the changing of the oil, the changing of the filter cartridge, the periodic checking for water or oil leaks, and the periodic checking of the critical components to be sure everything is working properly.

Suggested Maintenance for Any Misting Pump

As with your car, the misting pump uses oil to maintain lubrication and cooling within the crankcase.  It is easy to assume all is well because the pump continues to run, but if you wait until something fails, it will be too late.  The initial oil change should be once the pump is broken in after the first 50 hours of operation.  After that, oil changes should be made every 500 hours of operation.  All Fogco pumps include an hour meter to determine the proper time for the needed oil change.

The filters on the misting system are the last line of defense to prevent debris from entering the pump.  The cartridges should be inspected monthly and replaced at least once a year.  Dual filtration is also a good idea for areas that have extremely hard water or misting systems that are using well water.

In addition to oil and filter cartridge changes, all water pumps have rubber seals that are designed to wear (this is a necessity in order for the rubber material used to be able to seal around the pistons that create the pressure in the misting pump) and will need to be replaced whenever the pump begins to leak.  Typically, this will be between 500 and 2000 hours of operation depending on the specific misting pump design, the operating conditions, and the overall condition of the water supply.  The pump should be checked for water leaks every time the oil is changed.

Lastly, for all pulley drive pumps, the pulley belt should be checked each time the oil is changed.  If cracking or splitting of the belt is observed, the belt should be replaced.

Beyond the maintenance of the misting pump, there are other steps that can be taken to ensure a long life.  For pulley drive pumps, the motor pulley and the pump pulley must be perfectly aligned to ensure proper operation of these two critical components.  If you have any questions about the alignment of the pulleys, contact our Customer Service Department for steps to be taken.

The water supply to the pump is also an important factor.  It should be of sufficient quantity (at least twice the rated flow for the misting pump), sufficient pressure (most of the Fogco misting pumps include a low water pressure safety switch which will prevent the pump from operating if the water pressure is too low), and properly filtered.

The operating temperature of the misting pump should be as low as reasonable.  It is true that most misting pumps are placed in the outdoors and the Fogco pumps are designed and built anticipating this reality.  All of our enclosed pumps include an automatic exhaust fan to help maintain the temperature inside the enclosure as well as utilizing an over-sized bare pump so that the misting pumps rpm is reduced.  This has the effect of reducing the heat generated by the pump as well as extending its life by reducing the amount of cycles required to produce a given amount of flow.  However, if the mist pump can be placed in a enclosed area with a controlled environment, it can dramatically increase the pumps life.

Start by assembling the mist system tubing according to the instructions provided with the slip-lok components.  Once the mist line is assembled, hang the clamps as needed keeping them loosely secured around the tubing.  Place a clamp between each fitting.

Once all of the mist tubing is hung in place, turn on the misting pump and run the system for about 15 minutes.  This will allow the fittings to collapse onto the tubing securing them in place.  It will also create approximately 1/4″ of expansion of the mist line for each fitting.  This will initially cause the mist line to sag between each clamp.

While the system is still running, start at the beginning of the mist line and  secure the first clamp.  Work your way towards the end of the system making sure the mist line is tight as you secure each clamp in place.  Because of the expansion of the mist line, it may require some of the clamps to be removed and repositioned on either side of a particular misting nozzle fitting.

Once completed, the mist line should be perfectly straight and tight between each clamp.  If sagging does develop between some of the clamps, loosen the clamp, pull the tubing tight, and re-secure.  For the best results, always secure the clamps over the tubing while the misting system is operating under full pressure.

Over the last couple of years, Fogco has been focused on humidifcation applications for many different industries.  These industries include textiles, paper processing, woodworking, wine storage, and greenhouse humidity control.  In all of these applicatuions, increased humidification is required for maximum results from the product and/or the equipment that is used.

In many cases, to effectively control the humidity system, multiple zones are required.  this allows for a ‘staging’ of the mist system so that just the right amount of increased humidity can be introduced into the air at the precise time and in the proper area needed.  This multi-zone mist system design does provide for improved performance but it also presents a few challenges.

When a high pressure pump is built for a specific flow, it must create that flow when it is operating.  If the mist system has multiple zones and only one of the particular zones is required at a given time, the standard misting pump will still create its rated flow but it must internally bypass all the unused water.  This process creates heat within the misting pump and can cause premature failure of the pump seals or other critical components. In addition, the large pump is using electricity that would otherwise be unnecessary and this is seen as a waste of company resources.

One solution is to provide multiple pumps for a system that requires multiple zones.  Although this ‘solution’  does allow for a series of pumps to pressurize the exact amount of moisture that may be needed at any given time and it does ensure that only the amount of electricity that is needed is actually consumed, it is costly and cumbersome and dramatically increases the amount of maintenance time required for a system.

The preferred option is to design the mist system to include a variable frequency drive or VFD.  These unique controllers have the ability to change the operating speed of a motor so that one properly sized and designed pump can be used to operate a multi-zone system with flows that vary from 5% to 100% of the pumps total designed flow rate.

The advantages of these VFD designed systems are significant.  In addition to the elimination of the need for multiple pumps, the VFD has many different built in capabilities that can be used to enhance the operation and performance of the misting system.

Once of the most significant advantage, however, is the cost savings that the VFD provides.  Because of the way that the VFD operates (it essentially synthesizes the required alternating current by using a direct current),  it can deliver the required power to the motor much more efficiently using as little as 10% of the required wattage when compared to a system that incorporates a 1-pump option.  Obviously, the initial cost of a VFD system is higher than a comparable single pump option, but over time the cost savings can be significant and usually pay for themselves within a year.

If your system requires multiple zones and you think it might be worth considering a VFD design, talk to our Customer Service Department and let us help you determine if it is right for you.  It may be much less expensive over time than you expected.