Have you ever come across a situation where productivity, throughput or wear life just weren't what you expected? You reviewed your cone crushing operation but couldn't put a finger on what the solution might be. Bottom line results were suffering and you really needed the advice of a field expert who could make recommendations based on your plant equipment, climate conditions and application. Here's how two companies found the specialized help they needed with positive results.

In San Bernardino California, 4^th St. Rock Co. was experiencing a severe crushing problem with their 54" standard El Jay cone crusher. The large stones and boulders they were processing would need to be put back through the machine multiple times dramatically impacting their throughput. 4th St. Rock was only able to achieve 150 - 175 tons per hour due to the need to recycle the product. They looked to their local Unified Screening & Crushing Company - California Wire Cloth, for advice.

Upon evaluation, it was found that the El Jay was equipped with a fine liner that was not able to process the large stone material efficiently. The recommendation was to replace the old liner with an El Jay medium/fine liner, which opened up the crushing zone.

It was discovered that the bowl liner profile was too thick at the top causing inadequate feed for the application. The throat was too narrow impeding throughput and reducing productivity. The recommended solution was to install the correct Symons profile bowl liner that yielded the proper feed opening for the job.

Increasing production and maximizing throughput is nothing new. In fact, next to sizing accuracy a recent survey shows that throughput is the second largest concern amongst producers when surveyed to rank the factors most important when selecting screening media. But what happens when external factors such as market growth and adverse weather conditions impact your operations ability to meet the increasing demand and capture your share? Here's how one producer teamed with his local screening and crushing field specialist.

Over the past 3 to 5 years, Yahara Materials located in Waunakee, Wisconsin has experienced a dramatic increase in demand for clear stone products. These products are widely used for underground pipe and highway bedding to provide proper drainage. The product specifications required clean rock with minimal fines. Yahara Materials needed to find a way to increase their capacity to effectively capture their share of this growing market.

Yahara Materials operates seven 6 x 20, triple deck, portable crushing plants that were equipped with slotted, Tri-Lock, screens. These slotted screens became very problematic when faced with ever-changing soil conditions found at various locations, with increased moisture content present during the winter and spring months. They were unable to remove enough fines to get the product within specification. The slotted screens would blind over halting production and degrading throughput.

Upon the recommendation of their local Unified Screening & Crushing Company - Twin City Wire, Yahara Materials changed to a Stainless Steel 'W' style screen. This change greatly increased the flexibility of the screen and increased product flow. The 'W' style screen is composed of straight tension wires, 'W' shaped wires, and, custom cross wires. Three different wire sizes are used for a harmonic effect. This product allows greater open area than a square opening screen, and, increases throughput with this "harmonic effect".

In addition, the 'W' slots perform well during wet conditions experienced in the spring and winter months in the Midwest where more fines clog up and blind the screening process.

Yahara Materials now uses 'W' slotted screens on the bottom 2 decks of all their 6 x 20, Triple Deck, plants and have not had to change them out all season. The primary benefit is the significant reduction in downtime and maintenance allowing Yahara to increase production to meet growing demand. It is just one more example of the where having the right screening and crushing team makes the positive difference.

Whether your operation is large or small, keeping maintenance and downtime under control is critical to success. Management of maintenance and downtime issues directly affects throughput, productivity and ultimately profitability. Reactions to seemingly minor maintenance problems can severely impact efficiency if handled incorrectly. The balance between screening media selection, application, and, wear life must be carefully evaluated to avoid costly issues. To minimize the loss in productivity, you need to have the proper team of screening and crushing professionals help you choose the right solution for your specific application.

While woven wire cloth remains the most widely used screening media, many operators have turned to urethane based on its longer life and reduced downtime due to fewer change-outs. Choosing the best alternative for your application requires evaluation of tradeoffs.

Let's take a closer look at the trade-offs encountered by a South Texas ready mix manufacturer who operates a three deck 5' x 10'' Powerscreen, processing material into concrete, rock and sand. The Powerscreen was originally equipped with woven wire cloth screens on all 3 decks, and, set of the bottom deck measured 75" X 59 1/2" across.

The Powerscreen met the operation's needs, except when it came time to change-out the screens.The change-outs proved so difficult, the ready mix manufacturer went back to the OEM and contracted them to perform the screen changes four, or more, times a year. The screen cost was only $250 but the additional labor expense of $1,000 quickly became cost prohibitive.

A survey was conducted of original equipment manufacturers, screening media manufacturers and the National Limestone Institute producer members seeking information regarding the factors important in selecting a screening media. The results showed that sizing accuracy and throughput play the most important roles when selecting screening media The significance of this survey clearly supports the ultimate goal of an experienced screening and crushing team - to efficiently process materials, optimize throughput and minimize downtime. Read on to learn how this expertise was put to the test.

Stony Point Rock Quarry located in Sonoma California had purchased a new 8' x 20' - 3 Deck - screen machine. At the time of purchase, the OEM touted that the screen could achieve production throughput of 300 tons per hour. The bottom deck was an 8' x 4' panel , with a Piano Wire - 4mm (5/32") opening. This special screen deck was designed specifically for a Piano Wire Screen utilizing 3 crown support bars, for proper material flow, to prevent blinding. However, in reality the screen deck was barely able to reach a throughput of 100 - 150 tons per hour. Due to the material consistency and the flow over the crown surface, the screen blinded immediately.

Frustrated with the performance of the new screen deck, Stony Point contacted the OEM to remedy the situation. The OEM felt that the vibration settings were incorrect thus causing the lack of throughput performance. But adjustments to the settings were not the answer. "In addition to the severe blinding problem we were experiencing,?? stated Randy Swegle, the Foreman at Stony Point Rock Quarry's Soils Plus Division, "The screen cloth was only lasting one day. The wear life was absolutely terrible. The whole initial solution recommended by the OEM, was a disaster and we were ready to return the equipment to the OEM."

Before returning the Screen machine, Stony Point made a call to their local Unified Screening and Crushing Company - California Wire. Upon evaluation, the Unified representative immediately saw that there was insufficient tension on the screen. The tighter the tension, the easier it is to yield material flow thus avoiding material sticking to the screen surface and causing blinding.

It was recommended that the original Piano Wire Screen be replaced with a 4mm Stainless Steel (Piano Wire) Screen along with changing the profile of the rubber crown bar to improve the tension (at this point it was a 3 support bar system). This immediately improved production by eliminating 60 - 70 % of the blinding problem. Plus, it improved the wear life of the screens.