Tag: dust suppression

Big Dust Problem, Small Spray Nozzle Solution

Published on by Russ BowmanLeave a comment

A company that provides contamination control solutions to the mining industry needed to suppress dust from mined ore on a conveyor belt. Inexpensive spray nozzles supplied from the plant’s water system suppressed the dust, but resulted in a fair amount of runoff. This wasn’t an issue in a lot of their applications, but environmental regulations called for containment of the runoff from this particular material, so it was critical to minimize that runoff.

The conveyor belt was six feet (1.8 meters) wide and was relatively slow moving, so I specified two Model AF8020SS 1/8 NPT Internal Mix Flat Fan Pattern Air Atomizing Spray Nozzles, each capable of spraying up to 4.27 gallons per hour of water over a 47″ width at a distance of 15″ from the surface. This allowed for flexibility in mounting, and some overlapping spray in the middle, where dust suppression was needed most – and any excess spray would be contained in the bulk of the material.

Internal Mix Atomizing Spray Nozzles are the perfect choice for fine mist and precise control, which is critical for dust suppression applications.

At first, they were skeptical about the size of the 1/8 NPT Air Atomizing Spray Nozzle. The liquid nozzle they were using was “about as large as a baseball” and was supplied with a 1/2″ pipe. Once installed, though, they were impressed with the fine mist in the broad, thin pattern that was easily – and widely – controllable by regulating the air & liquid supply pressures.

From Round Patterns (left), to Flat Fan Patterns (middle), to Hollow Circular Patterns (right), EXAIR has Spray Nozzles to suit your liquid spraying needs.

EXAIR Air Atomizing Spray Nozzles are THE ideal solution when you need low flow rates – whether it’s for conservation of expensive liquids, eliminating drips or runs when applying coatings, or preventing runoff like in this application. If you want to find out how EXAIR can help you get the most out of the liquid you’re spraying – and your compressed air usage – give me a call.

Russ Bowman, CCASS

Application Engineer
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Benefits of Atomized Liquid Nozzles vs. Liquid Nozzles

Published on by Russ BowmanLeave a comment

There are a great many applications that require a spray (as opposed to a stream) of liquid. Certain droplet sizes, and flow rates, are beneficial for certain applications. For example, if you’re fighting a fire, you want as high of a flow rate as possible – the more water you douse the fire with, the quicker it goes out.  You also want a fairly large droplet size, since a mist would tend to evaporate instead of extinguishing the flames.

Pressure washers also benefit from higher (though not near as high as fire hose) flow rates, and droplet sizes.  You want an appreciable flow rate, because that means high velocity, and good sized droplets combine that velocity with their relative mass to “blast” away dirt and detritus from the surface.

Medicine delivery devices, like asthma inhalers, are designed to produce mid-sized droplets, but pretty low (and controlled) flows.  The droplets need to be small enough to efficiently spread the medicine through the breathing passages, but large enough to where they won’t evaporate before they ‘plant’ on the nasal & bronchial membranes to get absorbed.

These are examples of “liquid-only” nozzles…no other media or means of force are used to effect the spraying action.  Most of the time, the droplet sizes in these applications are measured in hundreds of microns, which “liquid-only” nozzles are ideally suited to generate.  Other applications, however, call for much smaller droplet sizes…such as those only attainable through atomization.

EXAIR Atomizing Spray Nozzles use compressed air to create a fine mist of liquid, with droplet sizes as low as 22 microns.

A typical “liquid-only” nozzle is capable of producing droplet sizes of 300-4,000 microns. Atomizing Nozzles’ droplet sizes are consistently under 100 microns, and can be as small as 20 microns!

Small droplet size is key to cost effectiveness in many applications:

  • Think about expensive coatings…the smaller the droplet size, the better and more even the coverage, and the less you have to spray (and pay) out.
  • Or humidification…smaller droplet size means more stays airborne, for longer, and in a larger space.
  • Petroleum based lubricants, by their nature, only require a thin layer for best results.  Smaller droplets make as even and thin of a layer as possible.
  • Dust control is much more effective with smaller droplet sizes, since the longer the mist lingers in the air, the more dust particles the individual droplets will adhere to…and then drop with them to the surface.  This also prevents getting the surface of the material any wetter than it has to be.
142 distinct models. 8 different patterns. Liquid flow rates from 0.1 to 303 gallons per hour. If you’ve got a spraying application, EXAIR has an Atomizing Nozzle for you!

If you’d like to discuss a liquid spraying application, I’d love to hear from you.  Call me.

Russ Bowman
Application Engineer
EXAIR Corporation
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Product Overview: No Drip External Mix Atomizing Spray Nozzles

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EXAIR’s Atomizing Nozzles are commonly used to clean, cool or coat parts as well as humidification or to control dust. They are constructed of 303ss, providing superior corrosion resistance and are able to withstand temperature up to 400°F (204°C).

The Atomizing Nozzles are separated into 3 categories – Internal Mix, External Mix and Siphon Fed.

For today’s topic, we will focus on the No Drip External Mix Atomizing Nozzles.

No Drip External Mix Atomizing Nozzles provide the highest flow rates

The External Mix Atomizing Spray Nozzles require a pressurized liquid source and compressed air source to produce a mist of atomized liquid. With the liquid and air being mixed external to the nozzle, they are able to handle higher viscosity fluids above 300 cP.

Our patented No Drip feature positively stops the liquid flow when the supply air pressure drops below 20 PSIG for 1/8″ NPT Nozzles or 30 PSIG for the 1/4″ or 1/2″ NPT. By incorporating this feature into the design, it eliminates the need for any additional valves or supply lines.

Available flow rates range from 2 GPH for our Model # EF9010SS 1/8″ No Drip External Mix Narrow Angle Flat Fan Pattern and up to 303 GPH for the Model # EF6010SS 1/2″ No Drip External Mix Narrow Angle Flat Fan Pattern.

When making a selection, there are 5 common considerations to take into account:

  1. How much liquid flow do I need?
  2. Is the liquid pressurized?
  3. What is the viscosity of the liquid?
  4. How wide of an area needs to be treated?
  5. What type of spray pattern fits the application?

If you have an application requiring a fine mist of atomized liquid or if you’d like to discuss another product or application, contact one of our application engineers for assistance.

Justin Nicholl
Application Engineer
justinnicholl@exair.com
@EXAIR_JN

 

 

Dust Suppression with an EXAIR Atomizing Nozzle

Published on by Lee EvansLeave a comment

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An EXAIR Atomizing Nozzle used to minimize dust in the feed bowl of a cement mixer.

One of the most difficult aspects of handling and working with dusty materials is suppression of airborne contaminants.  Small particles can easily become a dust cloud, minimizing visibility and decreasing the quality of working conditions.  This then leads to lower productivity, low morale, and a missed opportunity to maximize the potential of personnel and equipment.

Our distributor in New Zealand recently assisted one of their customers facing this set of problems when working with cement and microsilica as it was poured into a mixer.  An exhaust fan was in place, but failed to extract the dust sufficiently, so a new approach was needed to minimize the dust.

 

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An AN2010SS No Drip Atomizing Nozzle provides the needed dust suppression in this application.

 

The solution was to use an EXAIR AN2010SS No Drip Internal Mix Atomizing Nozzle, shown above in the red box, to produce an atomized water mist.  The dust produced during pouring is captured by the small droplets of atomized water produced with this nozzle, reducing the dust and allowing proper use of the mixer.

 

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The 9218 Stay Set Hose positions the atomizing nozzle where it needs to be.

 

In order to position the nozzle exactly where it needs to be, an 18” Stay Set Hose, shown above with the red arrow, was used to position the nozzle.  This hose is built specifically to have “memory” of the desired position, allowing for quick, easy, and repeatable position of the nozzle attached to the hose.

This simple setup is controlled through a timer to ensure water and compressed air use realize maximum efficiency.  It’s an easy solution to a painful problem for this customer.

If you’d like to explore how an EXAIR solution can solve problems in your facility or application, please contact an EXAIR Application Engineer.

 

Lee Evans
Application Engineer
LeeEvans@EXAIR.com
@EXAIR_LE