Mobile telescopic conveyor belt are becoming increasingly popular not only for their portability, but also their innovative designs that can work in countless applications. Designing a system requires both attention to detail and a deep understanding of your project goals. That can leave your head spinning when trying to see how a conveyor will practically fit into your plans.
But don’t worry, we’ve got you covered. In this article we breakdown the basics on how to choose the right mobile telescopic conveyor belt for you.
The Function of the Conveyor
Mobile Telescopic belt conveyors are made up of several strong steel sections, built into each other and stored at the base section when not in use. The primary function of the belt is to safely move materials with speed and efficiency.
The mobility of these units makes them arguably the most convenient conveyor belt to use. They offer an exceptionally wide range of material handling applications, ideal for operations that may require multiple project sites. There are a lot of options for customization in design, including adjustable heights and angling of the belt to meet all of your unique project needs.
So many configuration options can seem daunting at first, but with a clear understanding of your production scale, location, and material composition you can pick the perfect conveyor with ease.
Environmental Characteristics
You cannot always choose the location of your operation, which makes it critical to understand how environmental factors impact your telescopic conveyor.
Temperature
Climate can impact physical wear on your telescopic conveyor belt system as well as the composition of the materials you’re transporting. Thankfully, there are a number of upgrades you can choose that will protect your equipment and keep your machine up and running.
There are three grades of heat resistant belts you can choose from when working with hot or corrosive materials: HR(T1), SHR (T2), and UHR (T3). These belt types can handle a range of material temperatures from 125-220 degree C.
Keeping chute diameter wide can help avoid freezing inside the input ports and on the belt. Occasionally, it may be necessary to use plastic liners to avoid sticking on the belt surface, UHMW and PTFE plastic products are the industry standard.
Combating Corrosion
Generally, conveyor belts are made from a rubber or plastic compound combined with layers of fabric and steel cables. Because rubber belts are highly resistant to corrosion and abrasion, maintenance costs are comparatively low when handling materials such as alumina or sinter.
Corrosion can become a problem when operating with rollers on your telescopic conveyor that haven’t been treated properly. Having to maintain or replace rollers can become time consuming and even halt production. Luckily, there is a solution.
Internal corrosion can be prevented by incorporating a seal that protects the bearing from moisture or build up of material residue inside the rollers. Opting for rollers with centrifugal flinger seals will help prevent this kind of damage. This feature increases the centrifugal force, which aids in spinning out unwanted contaminants.
External corrosion to the rollers can be caused by extreme temperatures and other environmental factors. Salt water, humidity, acid rain, and altitude all cause corrosion.
When your equipment does corrode, this accelerates the process of abrasion, altering the properties of the surface and degrading layers of the roller material.
Utilizing polymer materials like Nylon and HDPE can help avoid external corrosion. These types of plastics are now engineered to match the ratings of steel in performance, while being resistant to corrosion from chemicals, salt, and moisture. Metal may rust and fall victim to the elements, whereas Nylon actually increases toughness when exposed to moisture; eliminating the risk of premature failure due to surface corrosion.
Material Characteristics
Depending on the materials you plan to work with, there are a few key factors to keep in mind when choosing the best telescopic belt conveyor to meet your needs. Material characteristics play a large role in functionality of your conveyor, which may require you to design a specific belt cover and structural frame for optimal flow.
Whether you’re working with fine sands, large and lumpy ore, or pulpwood logs there are specifications you can follow to keep your operation running smoothly.
Considering Types of Materials
The size and structure of materials that can be conveyed is limited by the width of the belt. Uniformly sized materials are carried with minimum degradation on a mobile telescopic conveyor belt. Particle sizes play a role in how material will spread or stabilize on your belt.
Materials like fine, dusty chemicals may cause sticking or packing when transported by other means, however conveyors are incredibly effective for transporting these materials. Even hot materials such as foundry, shakeout sand, coke, sinter, and iron ore pellets can be transported with ease on a telescopic conveyor.
Some materials will react to the movement of the conveyor in ways that you can predict, to better control your process. Coarse granules tend to settle quickly to a semi-stable condition, similar to a fluidized bed. This phenomenon makes the material capable of bearing loads because the contact points of the constituent particles came to rest in a structural array that formed a continuous load path of gravitational orientation. Due to irregular sizes, the particles will have to pass each other to fall in place. However, the range of density of coarse products is relatively small, with the density value varying depending on how the sample is prepared. Designers should consider the ‘worst’ condition when calculating their product’s density to accommodate for this variance.
What About Bulk Density of Materials?
Bulk density of your materials can be understood using the equation for tons per hour (TPH) of your conveyor.
Capacity (TPH) = 0.03 x Belt Speed (FPM) x material weight (lb. per cu. ft.)
You may also have to identify more than one density of material, for example, when dealing with material with biomass that can be compressed or fluffed-up, there will be different moisture contents. This variation results in different densities. It’s recommended when working with variables in material density to:
- Identify the size of your conveyor for the required tonnage, using the lowest density. This gives you the greatest volume to be handled. This is often the density of the materials when initially delivered to the vessel.
- Use your higher density for structural (load) and power calculations.
A common mistake in engineering telescopic conveyor mechanisms is that these variations in density are not considered, and thus the conveyor is too small or that the drive is under-designed.
How Do Material Specifications Affect Design?
Characteristics of bulk materials such as density, effective angle of internal friction, lump size and shape, are all factors which dictate the maximum incline angle material can be conveyed without having it roll or slip backwards on the belt. The max angle is typically 10-30 degrees depending on the bulk material – though this limit has increased with recent innovation in the field.
Making the material cover on the belt irregular will increase its ability to carry materials up slightly greater inclines. Even after manufacturing, cleats can be bonded or mechanically fastened to an already smooth belt cover. This modification allows the conveying angle to increase up to 45 degrees. Cleated belts are usually restricted to short conveyors where few or no return idlers are needed and either the material does not stick to the surface or where the carryback is acceptable.
Sidewalls can be added to improve the cleat approach. These sidewalls and a transverse rigid belt allow it to run flat without troughing idlers. These side walls increase the load carrying capacity over the ‘cleat only’ design, allowing for conveying up to 90 degree inclines.
Conveyor Parameter Selection
On average, belt width ranges from 18-96 inches. It is important when deciding on a belt speed that the belt width and conveyor capacity increase uniformly. The faster you need your belt moving, the wider it will need to be.
A belt must be wide enough to handle varied sizes of material, while not loading any pieces of your material too close to the edge of the conveyor. Your belt width will typically be determined by the loading chutes and the distance between skirt boards, to enable successful passing of material without jamming.
Standard mobile telescopic conveyor belt are built to handle operating speeds for 300-500 feet per minute. Depending on how many tons of material you wish to move per hour, you can generally follow this rule for sizing:
300 tons per hour – Use 24” belt
450 tons per hour – Use 30” belt
700 tons per hour – Use 36” belt
Power requirements may also vary depending on your output goals, and the parameters of the material you are working with. It’s important to consider speed and material composition when identifying the horsepower requirements.
When it comes to the length of your belt, there are some benefits to a longer machine. Short belts will experience the strain of loading materials and can wear faster, while longer belts will last considerably longer given proper alignment and matiencing. This is because longer belts face less impact. Once the belt has accelerated the material to the forward velocity of the belt, the lack of relative motion causes less wear.
It’s good practice to adjust loading protocols so that there is lower impact on the belt at input points. This will increase the lifespan of your telescopic conveyor.
Even though there are many variables to consider when choosing a mobile telescopic conveyor belt, the benefits of customization offer limitless possibilities for ease of use and longevity of your system.
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