Open territory: Boosting uptime with synthetic media

By |  January 25, 2015
Winter Brothers Material Co. is a family-owned operation located on the Meramec River, a tributary of the Mississippi.

Winter Brothers Material Co. is a family-owned operation
located on the Meramec River, a tributary of the Mississippi.

Producers boost throughput and uptime with the maximum open area and wear life of synthetic media.

Myth or fact – if you switch from wire cloth to modular synthetic media, you lose open area? Some may say it is fact; however, more operations are finding that notion to be a myth.

Some producers are realizing greater throughput and uptime with the maximum open area and wear life of modular synthetic media.

Such is the case for Winter Brothers Material Co., a family-owned sand and gravel operation that has been supplying the aggregate needs of the St. Louis area for nearly 70 years. The two founding brothers, George “Pete” Winter and Robert A. Winter led river trips in the region during the 1930s, and after serving in World War II they returned to the area and established the company in 1946.

Located on the Meramec River, a tributary of the Mississippi, Winter Brothers mines an alluvial deposit that is unique as to particle shape, uniformity and purity.

“Our region is blessed with the availability of the consistent-grade gravel and the lignite-free sand deposited by nature in this river valley,” says Ryan Winter, a member of the Winter Brothers management team.

At its Hagemann Plant, the facility’s main screening circuits produce six sizes of coarse aggregates and two sizes of sand products.

“Since opening the plant, we had always used wire cloth on all the decks of each screening circuit,” says Winter, who admits that his management team had long resisted the use of synthetic media, in large part owing to a concern over loss of open area.

Plant Superintendent Steve Klahs, a 30-year industry veteran, says that he was approached regarding the use of synthetic media years and years ago, and didn’t like the idea. “I thought it would inhibit production, but what we know now is that the use of synthetic media is saving time and money; and we are seeing an unbelievable increase in production – nearly double – on the fine sand particularly,” he says.

As to the open area of wire cloth, Klahs had not previously taken into account the amount of open area the operation had always been losing to material pegging and blinding. Winter says that the wire cloth panels they had formerly used were advertised as having maximum open area. “But they would blind up within the first couple of weeks and we would lose a significant percentage of throughput. However, the open area on the polyurethane panels gives us excellent throughput. We are particularly impressed by the open area we get on our masonry sand processing,” he says.

In early 2012, Winter Brothers installed modular polyurethane media panels manufactured by Spartanburg, S.C.-based Polydeck Screen Corp.

Maximum open area

According to the manufacturer’s regional sales manager, Joe Teague, the problem lies in how “open area” is typically defined and calculated. “Published open area percentages result in miscalculations in the specification of the screen area and vibrating screen size required for a given application,” he says.

The operation found that the modular polyurethane screen panels deliver greater open area and throughput, while resisting pegging and blinding.

The operation found that the modular polyurethane screen
panels deliver greater open area and throughput, while
resisting pegging and blinding.

“Many wire cloth catalogs list percentages of open area, which figure in all the openings in a section of screen. However, upon installation, a portion of those openings are blocked by bucker bars, crown rubber, clamp rails and center hold-downs. This,” he says, “means that the open area is significantly different, causing calculations to be off by up to 40 percent or more.”

In the case of many synthetic media brands, the open area is often calculated by ignoring the border. “The traditional panel has a large border or dead area around the perimeter that often is not taken into account, and again, the open area percentage is overstated,” says Teague.

Teague goes on to explain that engineering firms and end users are using these inaccurate calculations in plant-flow-analysis software programs, which ask them to enter the percentage of open area. “As a result, the plant may be designed with undersized or oversized vibrating screens.

“Open area,” he says, “should be calculated by taking the total number of openings in the screen panel and determining the percentage of actual open holes versus the complete surface of the panel itself. We suggest that customers take a very basic approach to comparing the open area between two manufacturers by simply counting the number of holes on each screen panel,” Teague says.

Maximum wear life

Klahs says that while Winter Brothers still uses wire cloth on the top decks to scalp off larger products, his company uses modular polyurethane panels on the middle and bottom decks. “Since we put them in more than two years ago, we have replaced only a few panels on the impact areas,” he says. “We are very happy with the wear life. When we were using wire cloth on those decks, we were changing out a screen or two on a weekly basis.”

Winter says, “I need to know that downtime is not going to be an issue, especially during times when we have to beef up production. In the past,” he says, “each of our decks would have five 4-ft. x 8-ft. sheets of wire cloth. When one of those screens would blow out, we’d have to shut everything down, pull workers off of other jobs, bring in a crane, switch out the screens – and that would take several hours out of production each time it happened,” he says.

Additionally, Winter acknowledges that when a wire cloth screen suddenly blows a hole, oversize material will fall through and contaminate product stockpiles. With modular synthetic panels, the maintenance crew can catch any wear issues before they become a contamination problem. If quality-control samplings are slightly off, this alerts the maintenance crew to check for any wear, and change out a panel or two.

Winter stresses the advantage of durability and the resulting labor cost savings when using the polyurethane panels. “If a panel wears through, it just takes one individual to pop it out and put another in,” he says, adding that while throughput and open area are important, durability is one of the biggest selling points of synthetic media.

“Our material is very hard. While typical limestone is a 3 to 4 (on the MOHS scale of hardness), our sand and gravel is a 7 to 8. So we are very pleased with the years of wear life that we are getting from these panels,” he says.

The facility recently switched from wire cloth to modular synthetic screen media on its middle and bottom decks to increase plant uptime.

The facility recently switched from wire cloth to modular
synthetic screen media on its middle and bottom decks to
increase plant uptime.

Proper product specification

After talking with several synthetic media manufacturers, Winter says that he chose Polydeck in part owing to his relationship with the local dealer, C.T. Fike Co.

“Dan Fike was very proactive in bringing in key members of the Polydeck team to closely examine our processes so that they could specify the right panel types for our applications and gradations,” he says.

The manufacturer’s approach begins with choosing from its library of more than 1,000 screen-panel-design options to correctly match the media to the vibrating screen parameters, making sure that the circuit will keep pace with the crushing side. All the product mixes are reviewed so that any potential gradation inconsistencies and plant bottlenecks can be identified and adjustments can be made upfront.

After capturing critical processing statistics, “what-if” scenarios are run to optimize media specifications to the applications, and to determine how any changing variables within the screening operations will affect overall efficiency.

“Polydeck assured us that they would guarantee that the panel configurations would allow us to meet the required specifications. If not, they would make any necessary changeouts at their cost. That gave us a lot of confidence when switching so many decks to synthetic media,” Winter says.

Since its installation, the synthetic media has allowed Winter Brothers to consistently meet industry specifications. More than 70 percent of its products are used in the ready-mix industry and perform well in a variety of Portland cement mixes. Products are also targeted to the roofing, masonry, asphalt, landscaping, septic-systems and extraction-well industries.

“Sometimes businesses stay with the same old methods because that’s the way they’ve always done things. That’s why we stayed with wire cloth for so long. But we eventually made the switch to synthetic media and we’re glad we did,” Winter says.

Take note

Engineering firms and end users often use inaccurate calculations in plant-flow-analysis software programs, which ask them to enter the percentage of open area.

 

Carol Wasson is a veteran freelance writer for the aggregates and construction equipment industries.

Allison Barwacz

About the Author:

Allison Barwacz is the digital media manager for North Coast Media (NCM). She completed her undergraduate degree at Ohio University where she received a Bachelor of Science in magazine journalism from the E.W. Scripps School of Journalism. She works across a number of digital platforms, which include creating e-newsletters, writing articles and posting across social media sites. She also creates content for NCM's Portable Plants magazine, GPS World magazine and Geospatial Solutions. Her understanding of the ever-changing digital media world allows her to quickly grasp what a target audience desires and create content that is appealing and relevant for any client across any platform.

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