Dry bulk tanks transport loads of the powders and resin pellets used to make the plastics in today’s yogurt cups, eyeglasses, pens, phones, and more. Dry bulk shipping, though no simple matter, is an essential part of supply chains today. The transport of tank loads of dry bulk is challenging indeed, particularly for newcomers. Let’s take a closer look at dry bulk transport and some of the equipment used.
The Truckers Known As Dry Bulk Carriers
The equipment used in the transport of dry bulk is pricey to say the least. Tanks that carry clay and sand run well upward of $110,000. For the transport of plastics, a special vacuum is needed with the trailer, and those together can run upwards of $140,000. Not to mention offloading and onloading equipment comes at an extra charge.
Now dry van trailers, on the other hand, can run somewhere around $3700 plus or minus.
So aside from price, what is the biggest concern for dry bulk carriers. In a word – contamination. Every time they get rid of one kind of load, before they can put another load in that tank, it must be thoroughly cleaned. Even the smallest residue from a prior load can contaminate the new load.
So worrisome is this possibility that for some loads (i.e., different colors of plastic pellets), many carriers have specific trailers for blue, some for black, some for white, etc. And then they have still other trailers for things like clay or sand. Imagine how pricey that can get.
The Tanks Themselves
The pneumatic trailer (an alias for dry bulk tank) is, more or less, a cylinder made of metal. At the bottom are a series of cone-shaped hoppers. At the top of the tank, manholes or a series of openings. There is a valve underneath each hopper which opens to a pipe which runs on the trailer’s underside. When the truck is being loaded, the valves are closed. The driver opens these valves when it’s time to unload. This allows the product to run into the outbound pipe from the hopper.
Blowers, Vacuums, and Hoses
When tanks haul plastics, vacuum units are needed. Along a hose, and through the bottom pipe, powder or pellets are suctioned to a receiving vessel such as a silo. Blowers are used in tanks that transport commodities such as clay or sand. They are less powerful than the vacuum units and about half the size.
Four inch in diameter hoses are used on dry bulk tanks out of and into the trailer. When offloading product to a silo or from a railcar, in order for these hoses to connect to other equipment, they may need adapters.
Volume and Weight
The density of commodities carried in dry bulk trailers varies greatly. The same volume of two different commodities can differ hugely when it comes to weight. In the transportation world, this can have big consequences. The gross vehicle weight limit set forth by the Department of Transportation states that these loads have to stay within an 80,000-pound limit.
Scales are included on some of the newer trailers which alert the driver (accuracy within a couple hundred pounds) how much onboard weight there is. The big scales, of course, are still used for precise weights.
Mickey Genuine Parts has, in stock, a variety of trailers and the parts that make them tick. Contact us today if you have any questions about our inventory or would like to place an order.