To determine Dry Fog System cost, we need to evaluate you material handling system. As for example, for conveying systems we need to have a process flow chart, indication of conveyor widths, speeds, locations, material characteristics and so on. Drawings, sketches, and photos are useful as well.  For DusTamer Wind Fence Systems we also require some data to evaluate. A good start is to complete the RFQ Dry Fog and/or RFQ DustTamer. From there we can contact you and provide a budget or firm price depending on your needs.

Operating Cost is typically much lower than collection or chemical systems (up to 4 times less). No chemicals to buy, no moving parts to wear out, lower energy use and so on. Please refer to our Technology Links/Pages for direct comparisons. You may also see  testimony from a PRB Coal Mine to the EPA comparing cost .

At DSI, we like to use a comprehensive approach and evaluate all of the site specific conditions in-order to engineer a solution. Please complete the RFQ form and supply project data via photos, drawings and descriptions of the of your facility and concerns. If your request is a Budget or Formal Bid  Request, you may wish to complete the form to contact us and obtain login privileges to access specifications, drawings, data and additional helpful resources. 

Dry Fog RFQ
DustTamer Wind Fence/Screen  RFQ 

We provide quick Budget Quotes as well as detailed Proposals that include a Detailed Scope of supply, Treatment Point Schedule and Piping & Instrumentation Diagrams.

Our Dry Fog System is designed in an easy to install modular format. Electrical Control Modules are Pre-wired to the Multi-Function Module and then mounted to a common galvanized steel frame. For air and water supply lines between modules and   nozzle supply lines, we eliminate hard piping by using instrumentation tubing that is housed inside of a flexible protective conduit . Our nozzle mounts bolt to their appliacation point, so no welding is required.

With Dry Fog Systems our customers typically install their own systems using employees or local contractors. Our systems modular format makes installation quick and easy.  We offer  Installation Supervision, Training and Start-up Services. Turnkey Installations our offerd on a case-by-case basis either by DSI or via local distributors and independent representatives. DustTamer Systems generally require a local contractor to install.

It is true fog just like nature makes. Meaning the majority of droplets droplets are between 1 & 10 microns in diameter. The importance of small droplets is there ability to impact and agglomerate airborne dust particles so the process material stays dry.

Fog systems when properly designed and applied can meet or exceed all air quality standards. The EPA now specifies fogging systems as Best Demonstrated Technology for Sub-bituminous coal.  In Wyoming, fogging systems are considered B.A.C.T. (Best Available Control Technology) for conveyors transporting PRB Coal, giving it a Zero Visible Emission Rating. At Rollover Rail Car Dumpers for PRB Coal, DSI has achieved reductions of over 96% as reported in Power Magazine .

Dry Fog is designed to only wet the not the material being handled. Typical Moisture Addition to the material is less than 0.05%. It has been estimated that our nozzle design can create enough fog to cover the area of 1/2 a football field with One Gallon of Water!

Slip stream effect

Yes, Dry Fog is the system of choice and is Best Demonstrated Technology for sub-bituminous western coals like PRB Coal. It used for other hydrophobic materials such as pet coke and fly ash. We make water droplets the same size as the airborne particles overcoming any surface tension issues. The Colorado School of Mines reported their research on how droplet size effects dust suppression in a 1976 issue of Coal Age Magagzine .

Dry Fog has been used specifically for a variety of moisture sensitive materials such as Clay, Nitrates, Limestone, Clinker, and even Cement.   We evaluate site-specific conditions to determine Dry fog applicability with some of these materials.  Typically, with moisture sensitive materials, Dry Fog works better on large open areas such as ship holds & dump pockets than it does with enclosed conveyor belts where it is possible for agglomerated material to build up and harden.

Dry Fog has the lowest BTU Penalty (chart source Martin Engineering) of any dust suppression system by far. Power Plant Operators report that they have not been able to detect any perceivable increase in moisture to the coal.

For refernece a grain of table salt is around 100 microns in diameter, sand around 50 microns. The human eye can see an object down to about 50 microns. So, an individual fog droplet tha is 1- 10 microns is invisible to the human eye, but in mass quantities it appears as fog. Refer to Droplet Size Chart

With Dr Fog, no chemicals are used. Chemical systems can have a Damaging Effect (see article) on conveyor belts. Surfactants are designed to break up the surface tension of the water droplet to increase its distribution into the material.  Dry Fog produces microscopic droplets that collide with airborne particles and have very little surface tension. Binders are designed to make the material stick together. Dry Fog agglomerates dust via like size droplets to dust particles and the electrical charges present.

Yes, Dry Fog is often the only practical solution for Dump Pockets. We fill the pocket with fog prior to the dump and continue the fog output through the duration of the dump cycle. At PRB Coal Rollover Rail dumps we have achieved reductions in excess of 96%! At DSI we can evaluate the feasibility of controlling dust from your dump pocket.

There are several  issues with using Dry Fog at Stack Out Conveyor Discharge Points.   Generally, there are three sources of  dust generation: (1)  separation of the fines coming off of the belt, (2) separation of the fines as the material free-falls and (3) the impact of the material onto the storage pile.  In some instances, the discharge chute can be enclosed with Strip Curtains and positioned close to the pile. In other cases water sprays must be added at the tail of the conveyor to pre-moisten the material before it stacks out. Typically, we can indicate to our customer's the feasibility of using Dry Fog at Stack Out Conveyors given drawings and photographs. DustTamer Wind Fence Systems are another control measure we use for storage piles.

Dry Fog is designed as a stand-alone dust suppression system and typically replaces the bag-house. Collection can be used upstream or downstream of the fog application point as long as it is far enough away to prevent the fog from being sucked into the collector.

Because Dry Fog is designed to treat only the airborne dust using microns sized droplets, very little moisture addition takes place, so there is little if any Carry Over Effect. Dry Fog is injected into each point of dust creation similar to a bag-house collection system.

Yes, you need an adequate supply of compressed air at 80 to 90 PSI. The volume of air required is determined by the quantity of nozzles and type of nozzle selected for that application.  Instrument air is not required as we are able to filter most air sources within our system.

Dry Fog systems operate between 7 and 15 pounds water pressure. Typically, we ask for a source that maintains around 50 PSI water pressure.

In addition to our standard  two-stage filtration for water and compressed air, the nozzle design itself has many features to prevent plugging. (1) there are 4 to 8 water orifices per nozzle, each being .028 inches in diameter or larger. (2) our fine atomization occurs outside of the nozzle via sound waves as opposed to squeezing water through an orifice to atomize, (3) the shock wave produced by the nozzle design to shatter the droplets to a micron size, vibrates the nozzle like a sonic cleaner, (4) our low water pressure means the low-pressure drop from 15 lbs maximum delivery pressure reduces the chance for nozzle plugging minerals to come out of suspension (like happens with high pressure nozzles).

D.S.I. is unique in that we offer four different flow rated Dry Fog nozzles.  These nozzles are interchangeable within our system, so we can adjust the amount of fog output per nozzle to site-specific conditions. Our Nozzle Specification Chart indicates where each nozzle is typically used along with associated air and water Flow Rates.

We ask for the best available safe water source, as volume requirements are low and cleaner water will extend filter life. Water should be free of harmful contaminates and as clean as possible.  We realize that all water systems are subject to particulate so, DSI provides a permanent media primary filter with an automatic back flush coupled with secondary disposable filters as a standard feature. Dual parallel by-pass filters available for un-interrupted operation.

For open dump pockets we sometimes require a DustTamer Wind Screen to reduce the effects of wind and displaced air caused by the dump. This shields the dump pocket from ambient wind and increases fog and dust retention time.

Dry Fog works very well in below freezing conditions. Fog droplets lack sufficient mass to freeze. This phenomenon is known as Cloud Physics.  The system components can be protected via insulated enclosures with self-regulating heaters and heat tracing as well as an automatic purge system upon system shutdown.

No water pumps are typically required. We ask for a minimum of 30-PSI water at the elevation of fog application. DSI can supply water pumps and storage tanks if required.

In many cases no modifications are required. For conveyors, we need a covered head chute and a cover with skirting at the conveyor loading zone. If the receiving belt cover is too low it may need to be raised and sometimes lengthened to reduce the velocity of the dust laden air.  Enlarging the load zone covers, slows air movement and increases the fog-dust retention time, allowing the fog to agglomerate and remove the airborne dust. DSI supplies Dust Curtains and DustTamer Wind Screen Systems to help reduce the amount of air movement at transfer points.  DSI can review your transfer point data to determine what if any modification may be required.

DustTamer wind screens and fences exert a drag force on the oncoming wind velocities allowing a portion of the wind volume to penetrate or bleed through the screen and deflecting the remainder of the wind around the sheltered area. This lowers the velocity below the point required to initiate particle movement.  Typically, the fence or screen is located on the upwind side of the are you want to protect creating a wind protected or lee zone downstream.