AT R.E. PIERSON’S STONE YARD IN NEW JERSEY, W.S. TYLER CONDUCTED SPECIALIZED FIELD TESTS FOR A NUMBER OF AGGREGATES PRODUCERS.
By Mark S. Kuhar
This is the second in a new series of personal accounts called “Quarry Stories,” written by the editor of Rock Products, bringing you perspective and insight gleaned from more than 20 years of covering the equipment, technology, plant operations and people that make the aggregates industry great. –Ed.
It is the 25th anniversary of the movie Field of Dreams, which famously contains the line, “If you build it, he will come.” That movie and phrase came to mind when I attended a special field test conducted at R.E. Pierson’s Bridgeport, N.J., stone yard and asphalt plant, where a number of aggregates producers had dreams of finding an answer to their production problems. W.S. Tyler built a special test plant to address those problems, and producers certainly came to see it.
W.S. Tyler, based in St. Catharines, Ontario, Canada, and distributor Kemper Equipment, Honey Brook, Pa., demonstrated the Hydro-Clean Mobile Test Plant at the Pierson site on May 22. It is the same machine that many producers across the country saw in Las Vegas if they attended this year’s ConExpo-Con/Agg show.
The Hydro-Clean Mobile Test Plant enables operations to test Hydro-Clean washing technology before committing to a capital investment. Aggregates producers from Pennsylvania and New Jersey attended the event, and each transported more than a few tons from their own quarry to see how the unit performed on their own specific problem material.
The many piles of rock, sand and clay mixtures – all different colors, textures, sizes and geologic composition – made quite a sight laying side-by-side in the stone yard.
“The new Mobile Test Plant is completely self-contained to make testing as easy as possible for our customers, and provides results that clearly illustrate how the technology can add value to their operations,” said Michael Honea, W.S. Tyler process engineer.
|The test plant enables operations to test Hydro-Clean washing technology.|
Who is R.E. Pierson?
The R.E. Pierson Co., like many construction-materials firms in this industry, has a unique history. After several years operating as a sole proprietorship, Richard Pierson incorporated the main operating company, R.E. Pierson Construction Co. Inc., in 1980. Since that time he and key employees have propelled the company's steady growth in expertise, revenues and scope of services to the present day level.
Initially concentrating on residential and commercial site development, Pierson began performing an increasing volume of public projects for local, county, state and federal agencies. The company also further penetrated the retail and industrial site development market.
Over the years, the company has added greatly to its scope and strength of operations. They have accomplished this by increasing the services it performs, including asphalt paving, site concrete work, asphalt production (with plants in New Jersey and Delaware), concrete production (in New Jersey), structural and concrete construction (retaining and sound walls, dams and bridges), concrete paving, demolition, and the production of crushed stone, sand and gravel.
As revenues and the scope of the company’s services have grown, so has the size and complexities of the projects undertaken. In additional to New Jersey and Delaware, the company also operates in Maryland and southeastern Pennsylvania, along with nationwide potential for its demolition operations.
|Hydro-Clean employs high-pressure nozzles to spray up to 90 percent recycled water on the material.|
What is the Hydro-Clean?
The Hydro-Clean washing unit from W.S. Tyler is designed to clean deleterious material from aggregate, recycled and other minerals while reducing water consumption by up to 75 percent over traditional log washers. Sounds good so far, right?
Unlike traditional washing systems which can require up to three screens along with a log washer or screw, the producer only needs an additional wash screen for the Hydro-Clean’s discharged material.
Taking a maximum feed material size of up to 6 in. into its vertical drum, the Hydro-Clean employs high-pressure nozzles, rotating at 90 rpm, to spray up to 90 percent recycled water on the material with pressures up to 2,900 psi (200 bars).
The washing unit removes silt and clay particles as small as 63 microns from mineral mixtures and, with its short retention times, can process up to 360 tph, depending on model size and application. Due to its compact size and weight, overall operating and structural costs are considerably lower than with traditional washing systems – which also require more equipment and a greater footprint, company representative informed me.
The Hydro-Clean consumes little water and power. Water consumption ranges from 27 to 211 gpm, depending on application and model size – compared to log washers that can require up to 800 gpm of water, according to the company.
Power requirements for the Hydro-Clean are no greater than 300 hp (225 kW) on its largest model. When compared to conventional systems, the Hydro-Clean experiences little wear with a maintenance-friendly design that allows for easy exchange of the few standard components that are subject to wear.
Ideal for use in clay-heavy material deposits, dirty material is fed via hopper to a vertical washing drum, where high-pressure nozzles mounted at the top rotate and spray the material with water. The water streams spread and wash the material at pressures of up to 2,900 psi, effectively interacting with the material to break up agglomerates and clean the particles of stubborn material. The turbulence in the drum creates additional scrubbing and abrasive forces that enhance the cleaning process as the material travels down the drum cylinder.
High-pressure streams of water are injected into areas of the rock (holes, cracks, etc.) that are difficult to reach with traditional cleaning methods like log washers or screws – creating a cleaner product that generates higher selling value. In addition, many producers use this unit to turn material that was once dirty waste into revenue.
During the cleaning process, the washed material works its way down the drum and exits onto a discharge conveyor that leads to a standard wash screen, removing any remaining dirt or clay still on the stone as it fractionates the material. The resulting dirty water flows through polyurethane screen mesh installed in the sides of the washing drum. It is collected by a waste water pipe, which sends the water to a treatment system for additional fine screening.
The distance between the washing rotor and the material bed in the Hydro-Clean is variable and allows the system to adapt to various material types. Level sensors located at the material feed inlet provide exact data to the PLC control unit, ensuring a consistent material flow into the system.
The Hydro-Clean is available in three model sizes that produce 18 to 360 tph depending on the application.
|The many piles of rock, sand and clay mixtures — all different colors, textures, sizes and geologic composition — made quite a sight laying side-by-side in the stone yard.|
Testing Opens Eyes
For many years, R.E. Pierson has been involved in the production of virgin and recycled aggregates. Initially on-site rock crushing was performed at various site-development projects. The crushed material was used as pavement sub-base material and pipe bedding.
Larry Zamkus, a W.S. Tyler certified sales manager, was one of the local representatives on-site, working with field representatives from Kemper Equipment. He made a good point about how it is one thing to talk about a piece of equipment or show a video of it, but quite another to see it in person.
Richard Pierson Jr., owner and president of Pierson affiliate Diamond Materials, and son of the company’s founder, was first in line to have a look at how the machine performed. “The machine speaks for itself,” he said. “Today we washed the heaviest clay content we have in our pit so we could to see the worst-case scenario test for that particular source. Overall, we’re pretty happy about what we see.”
“We have a pretty good demand for cleaning the rock,” he said. “We consistently use a log washer, and there is a lot of wear and a lot of maintenance that goes with that type of machinery. That’s why we’re looking at this machine.”
Pierson noted how water usage influenced his opinion of the machine. “The water usage is minimal, that is always a good thing. You have a minimal amount of water and a minimum amount of water-out going back into the pond, and we can contain it pretty easily.”
Prior to the event, aggregates producers operating regionally had an opportunity to truck several tons of their own specific material to the Pierson site to see first hand how well the machine cleaned it.
Lou Mitschele, owner and president, Baer Aggregates Inc., of Phillipsburg, N.J., was one of the producers who traveled to the site to see his own material processed. Baer’s operation specializes in crushed stone, natural stone, round gravel, decorative gravel and sand.
Baer Aggregates serves customers throughout New Jersey and adjacent counties in surrounding states. In addition to dolomite stone, Baer gets sand and gravel from its quarry. The top layers are heavily stratified with dirt and clay.
“It’s a very stratified mountain, especially the upper layers out of dirt and clay,” Mitschele said. “I have about half a million tons of that material hanging around. I need a way to get rid of it, one, to give me room, and two, to give me a sellable product.”
To date, Baer has been selling the material as pack and fill at $3-6 per ton. By pre-washing the material and then running it through the Hydro-Clean, Mitschele said he thinks he can make 3/4-in. material, maybe even 3/8-in. and turn it into material that might sell at $10-12 per ton.
“You get a lot of flat, slabby pieces, so the 3/4 would be good for commercial stuff, putting under concrete,” Mitschele said. “I wouldn’t want to sell it to any of my concrete producers. Likewise with the 3/8, I’d have to look at it and see how slabby that comes out. But as it comes out (of the Hydro-Clean) as a whole, I could add screenings to it to make a nice CGA product out of it or a QP. Or if I do my whole pile, I could end up with 300,000 tons of nice, usable material that otherwise would have taken up a lot of room in my place.”
|Power requirements for the Hydro-Clean are no greater than 300 hp (225 kW) on its largest model.|
A variation on the plant has just been introduced by W.S. Tyler. The company has added mobility to the list of benefits of the Hydro-Clean washing system. The company now offers the ability to mount the machine on a chassis for easy movement from place to place within a quarry or even from jobsite to jobsite.
“The Hydro-Clean is unique in the industry,” said Matthias Bremer, innovation engineer at W.S. Tyler. “Making it mobile delivers the flexibility to locate washing closer to the actual job and reposition it as necessary to boost efficiency, while delivering all the same profitability and environmental benefits of a stationary Hydro-Clean.”
In the End
Over the years, I have had the opportunity to see equipment demonstrated for use in the field many times, at working shows such as Hillhead in Buxton, England, and the WHEN recycling expo when it was held in York, Pa. I have also seen material produced on-site at manufacturing facilities and one-on-one at quarry operations.
The opportunity for quarry operators to see their own material produced, and to analyze the end result immediately at the Pierson site really opened up the eyes of the producers who traveled to this demo.
If we know anything about aggregates producers, they are all from Missouri. In other words, they all maintain a “Show-Me State” attitude. Also, they cannot be fooled by cheap tricks and pyrotechnics.
I always welcome the opportunity to see “in-the-field” testing, as aggregates producers seek the new technology and specialized equipment they need to solve a production challenge and enhance productivity.