At one end of the tripper system, the railcars carrying the incoming aggregate are positioned over the in-ground hopper. The material is dumped into the hopper where it is picked up by the feed conveyor (above) and moved up to the overhead tripper conveyor (right). The feed conveyor transfers aggregate from the hopper to the tripper conveyor at a rate of 800 tons (725 tonnes) per hour.

feed conveyor transfers aggregate


Unusual circumstances can create unusual problems—and unusual problems often call for unusual solutions. Such was the case with a producer of hot-mix asphalt (HMA) a few years ago. One thing led to another: unusual circumstance, problem, and solution. Here’s the story: The company is in the business of paving highways and performing other heavy construction work. Because of the paving business, their HMA plant uses a large amount of aggregate on a daily basis.

The Unusual Circumstances

The unusual part of the operation is that there is no suitable supply of aggregate nearby in the area where the company does business. For years, they had either brought the aggregate in by truck or by rail, depending on its origin. Then they had the opportunity to get their supplies from a quarry that was an additional 30 miles (48 km) away—which was simply too far to haul by truck.

They decided to commit to hauling most of their aggregate in by rail to a spur line that was adjacent to their property. In that way, they could get all of the aggregate they needed, when they needed it.

The Unusual Problem

Unfortunately, the railroad spur line was located quite a distance from their HMA plant: about 300 yards (275 meters). After unloading the material from the rail cars and stacking it, they had to use front-end loaders to move it to where thev were stockpiling the material for the plant. The result: a lot of man-hours used, a lot of hours on the loaders…and a confusing amount of back-and-forth traffic in a plant yard that was already crowded with haul trucks lining up to get hot-mix.

The Unusual Solution

The company’s management approached Kolberg-Pioneer to see if their engineers might have some input. They were in the process of purchasing a new HMA plant from Astec, Inc. and they were interested in solving the problem before the new facility became fully operational.

Together, the two companies worked out a solution that has generated interest from a number of companies that deal with aggregate materials. The solution involves a rail-car unloading facility and a tripper conveyor that is used to transport the material a long distance and then stack it.

In the past, the material was handled numerous times. Thev moved it out of the pit where the rail car had dumped it; then they stacked it; then they moved it with a loader or excavator and stockpiled it; then thev moved it once more to the HMA plant’s cold-feed bins.

But with their new tripper system, the material moves automatically from the rail-car unloading pit to the stockpiles. The only time they touch it is when they send a loader to fill the cold-feed bins— and those cold-feed bins are only about 30 ft. (9 m) away.

The results have been impressive:

The company was able to reduce both the size and activity of its loaders. It was able to reduce the number of man-hours used in moving material. Traffic around the plant was improved dramatically. And at the same time, they were able to increase the production capabilities of the HMA plant.

Surprisingly, the design of the tripper system is unusually simple and straightforward. It requires only a relatively small footprint in order to work properly. And it could stretch almost any distance.


The Unique Tripper System

The system designed by Kolberg-Pioneer for this company consisted almost entirely of just three basic components: a rail-car unloading station; a tripper feed conveyor; and a stationary tripper conveyor. Here are some of the details:

Rail-car unloading station—There is a stationary, underground hopper with a top opening measuring 14 x 38 ft. (4.3 x 11.6 m). The hopper slopes are 60° and there are hinged, false hopper walls with vibrators to prevent the aggregate from hanging up on the walls. There is a 36-in. (0.9-m) conveyor belt that assists in the collection of the material for subsequent transport to the tripper feed conveyor. This belt was designed to move aggregate material at a maximum of 800 tons (725 tonnes) per hour.

Tripper feed conveyor—This unit is a Kolberg Series 46 stationary, vertical-curve tripper conveyor that is approximately 225 ft. (69 m) long. Some of this conveyor is underground, although most of it is above ground level. The tripper feed conveyor carries the material up to the elevated tripper stockpiling system.

Stationary tripper conveyor—This particular component is a Kolberg Series 40 conveyor measuring 36 in. (0.9 m) wide. The system was built to carry the material across five aggregate bunkers for a total distance of 450 ft. (137 m). There is a traveling tripper and a manual flop gate chute that allows the material to be discharged to either side of the conveyor. There is also a special chute at the far end of the tripper conveyor that allows it to feed material directly onto the facility’s radial stacker that is located abut 25 ft. (7.6 m) beyond the last bunker.

According to a spokesman of the company that has been using this system for the past several years. “We gave ourselves the ability to unload more material at a higher rate, thus being more efficient. We were trying to reduce our costs—and that is what we have been able to do.

“This is an incredibly efficient operation. We’ve been able to store more material on a smaller footprint. And that, by itself, has been a big advantage.”


Old-fashioned cone crushers face stong competition from this new design and superior technology

People in the industry may think they know cone crushers pretty well since those hard-working crushers have been around for a half century or so. But a producer who hasn’t specced out a cone crusher lately may have a slightly outdated perception of this equipment. For example:

There have been complaints about some old-style cone crushers, complaints that usually called attention to four of their major short-comings: (1) their relatively low productivity; (2) their struggle to produce cubical material; (3) their need to be constantly monitored during production; and (4) their need for frequent adjustments to maintain spec material.

The fact is that the modern cone crusher manufactured by JCI defies those perceptions. The Kodiak Series of cone crushers offers producers more capacity, better quality of aggregate output, and requires less human interface. In short, these new crushers are bigger and better. Here’s a quick overview of how the Kodiak Series cone crushers have been engineered and built to redefine cone-crusher quality:

The Kodiak Series of cone crushers from JCI features improvements in three major areas. First, they have higher capacity. Second, they have a better quality of aggregate output. And third, they require less human interface.

In order to achieve this, JCI redesigned the cone head. Their engineers changed the geometry of the cone head to a steeper angle compared to that of conventional cone crushers. Because the geometry is steeper, material is forced by gravity through the chamber at a faster rate.

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