Cleaning up

By |  March 1, 2014

One New Jersey sand-and-gravel company moves more inventory thanks to a material washing system.

W.S. Tyler Hydro-Clean

Dun-Rite Sand and Gravel, Vineland, N.J., has been dredging and mining sand, gravel and clay for more than 45 years.

Dun-Rite Sand and Gravel had a big problem — one that weighed approximately 15,000 tons at the beginning of 2013, and was getting bigger by the day.

The company was taking clay, gravel and sand from the man-made pond at its Vineland, N.J., location with a 14-in. Marlin dredge and pumping it to the surface. It screened and sorted materials, then put them through a coarse material washer. From there, the sand went into twin classifying tanks, where it was re-blended to meet certain specifications. Dun-Rite sold the materials primarily for concrete sand, pipe bedding, and paver and masonry work.

But with every pump out of the lake came stone, too. There was lots of it, and it was caked with dense, sticky clay. The material needed to be washed before anyone would buy it, but the site didn’t have space for a log washer.

Dun-Rite was between the proverbial rock and hard place: No one wanted to buy the dirty stone, but the company couldn’t afford to keep using space to stockpile it, either. Worse yet, even with all of those tons just sitting there, Dun-Rite had to buy stone from a vendor to resell to customers who wanted it. Unfortunately, Site Manager Tony Pizzo wasn’t aware of any alternatives that would handle the job and meet site needs. So there the stone sat, a daily reminder of revenue left on the table.

W.S. Tyler Hydro-Clean

Dun-Rite Sand and Gravel is in full production after adding a Hydro-Clean to wash its stone.

Traditional technology
Dun-Rite has been dredging and mining sand, gravel and clay for more than 45 years, and it opened the Vineland site in 2002. At previous sites, the company used a combination of coarse material washers and log washers to clean everything, including stone.

Log washers feature numerous paddles mounted to two shafts that rotate. The force of the rocks impacting one another removes clay and other waste materials. It’s a simple process, but it comes with some sizable requirements. The machines use up to 800 gpm of water, require a significant amount of energy, and take up several hundred square feet.

The Vineland site simply was not large enough to accommodate a log washer in Dun-Rite’s in-line configuration, which was necessary to keep the process efficient and profitable. To use one, the company would have had to place it away from the dredging plant. In addition, it would have required a larger pump, which would have meant even more cost and space. In short, the technology and equipment that worked for Dun-Rite in the past was not a solid option for Vineland.

“We used log washers before and they cleaned the stone very nicely, but they are slow and require a lot of maintenance because they have a lot of wear parts on them,” Pizzo says, noting that to keep log washers working efficiently and effectively, operators need to keep them filled with material at all times. Dun-Rite was getting a lot of stone out of its pond, but not consistently enough to do that.

W.S. Tyler Hydro-Clean

Dun-Rite Sand and Gravel raised its coarse material washer 5 ft. to feed stone directly into the Hydro-Clean.

“In terms of technology,” he says, “it’s like taking your clothes out to wash them on a board compared to using a washing machine.”

Seeing is believing
Pizzo was introduced to the Hydro-Clean for the first time in 2011 at W.S. Tyler’s booth during ConExpo-Con/Agg. He learned how the Hydro-Clean could effectively clean aggregates, industrial minerals and metals with as much as 75 percent less water than a traditional log washer and washing drum — and do it within a smaller footprint. He requested a demonstration.

In April 2013, Larry Zamkus, a certified sales manager at W.S. Tyler, arrived at the Vineland site with a Hydro-Clean mobile test plant. In addition to the Dun-Rite crew, several other producers came out to see the equipment in action.

Zamkus and his team washed stockpiled stone and some stone directly from the dredging plant. The mobile test plant not only removed tough sticky clay effectively, but also performed considerably faster than log washers.

“We were very surprised to see how quickly the machine worked, and we were shocked at how it could clean with far less water than a log washer,” Pizzo says.

How it works
The Hydro-Clean easily removes impurities from stone up to 6 in. in size. The HC1000 can process up to 180 tph, which in Pizzo’s experience is way faster than any other cleaning machine.

Material enters the machine’s drum; the washing head spins in a vortex, and high-pressure water nozzles remove contaminants from all surfaces and crevices. The machine also gives material one final wash on the rinse screen to remove any remaining clay or dirt.

W.S. Tyler Hydro-Clean

Previously, Dun-Rite Sand and Gravel stockpiled more than 15,000 tons of material because it didn’t have equipment to wash it efficiently.

Even with its ultra-high water pressure, the Hydro-Clean requires between 26 and 211 gpm of water to operate — significantly less than traditional washing systems that can require up to 800 gpm. In addition, robust filtering technology allows water to be re-circulated through an operation’s water treatment system and used again. With the recycled water, the Hydro-Clean only requires 10 percent fresh water to operate effectively.

It’s also a much faster process: Whereas material needs to be in a log washer for three minutes or more, retention time in a Hydro-Clean is just a few seconds.

In terms of maintenance, the Hydro-Clean offers several advantages over other cleaning systems, Pizzo points out. Log washers, for example, have numerous parts that need regular maintenance, including bearings, belts and paddles. While the paddles are made from hardened steel, they tend to wear from the harsh abuse of the stone. They need to be replaced at least once a year, and it is a labor-intensive project that can take three or four days.

Low-energy consumption is also a benefit. The Hydro-Clean requires no more than 350 hp on its largest model, which is 15 percent less than a log washer. In addition, Pizzo says, because the machine stops when there is no stone in the drum, it saves more energy and water and there is less wear on the machine and its parts.

Equally impressive to the Dun-Rite crew, Pizzo notes, was its compact size. The Hydro-Clean is available in three model sizes, so there was one that fit into the operation without requiring any major changes to the dredging plant.

W.S. Tyler Hydro-Clean

With W.S. Tyler’s HC1000 Hydro-Clean, the company can clean and sell its stockpiled and newly dredged stone.

Dun-Rite had seen enough to make the purchase, and W.S. Tyler dealer Kemper Equipment and W.S. Tyler technicians installed an HC1000 at the Vineland site. Pizzo and his crew quickly put it to work, washing stone directly from the lake and from the stockpile.

A one-two combo
Dun-Rite is still using its coarse material washer, which breaks up the clay, but now the material goes from there directly into the Hydro-Clean. At press time, the new combination has been in operation for only a few months, but the company is already seeing an improvement in efficiency and profitability.

Pizzo reports that Dun-Rite picked the Hydro-Clean for four major reasons: It had fewer wear parts than other cleaning machines; its small footprint was ideal for the in-line operation; it required less energy; and it used less water. In Dun-Rite’s case, water usage has dropped from 600 to 800 gpm to approximately 100 to 125 gpm.

But Pizzo is also quick to point out other, less-obvious benefits that have made the purchase a wise decision. For example, the Hydro-Clean saves time and labor costs when temperatures fall below the freezing point. At previous sites, to prevent water from freezing in a log washer, the Dun-Rite crews had to empty it completely every time they shut down. Filling and emptying the machines over and over again took a lot of time because the machines are so large. With the Hydro-Clean, water fills and drains almost instantaneously.

Dun-Rite also has regained a revenue stream lost when it moved operations to Vineland. Rather than buying and reselling stone, the company is now selling its own stone to monument companies and septic contractors. When Dun-Rite was selling stone from a different company, it was only making $1 a ton. Now it’s making $10 a ton — a 1,000 percent increase. In addition, the stone is much more valuable than sand, and is now the company’s most profitable product.

“I’m glad to have it,” Pizzo says of the HC1000. “It works very well with very little maintenance, and with just one pass, the stone comes out clean.”

Take note
Because the Hydro-Clean stops when there is no stone in the drum, it saves more energy and water with less parts wear compared to log washers.

Photos: Dun-Rite Sand and Gravel

This article is tagged with , and posted in Features

About the Author:

Comments are closed