Dry Bulk Pneumatic Tankers

[Big Bill]

Dry bulk pneumatic tankers - three hopper/four hopper/five hopper styles can be very deceiving to the inexperienced driver, for loading, pressurizing, and unloading - BUT BEWARE. These tankers can be some of the most dangerous pieces of equipment on the planet.

Some of the common manufactures of these units are Heil, Fruehauf, Boyd, and Trailmobile just to name a few.

Special training is required to load, haul and unload this units. And although they may seem easy to operate, a rookie’s first impression like this can be his/her last.

Many of these units have top loading hatches that are secured by numerous folding “binding handles”, and when under pressure trying to re-secure these “binding handles” to stop a hissing leak can be fatal.

Many of these units can be pressurized by either a PTO off the tractor, or my a supply line feed provided by the receiving company. In any event, most receiving companies will have a MAX PSI that the driver/unloader is NOT to exceed. This is primarily due to the receiving sensors, material flow design inside the storage or production line facilities.

Another consideration is clogging the unloading line that runs along the bottom of may of these tankers. Whether it be lime, sand, ash, four, plastic pellets, or some other commodity - keeping a steady tank pressure to force material down through the hopper valve, the accept the blowing flow along the delivery line along the bottom of the tanker ... with consistent pressure... is an art worth studying and following religously. Being over confident and trying to “push” too much material along the delivery line usually results in a clog. Clogs are time consuming, dangerous and messy.

All of the pneumatic tankers that I’ve mentioned above all have a host of gauges that require constant attention and monitoring. Over confidence usually means neglecting one or more gauge which can be fatal. Over pressurization can damage the hopper dump values, block feed lines, stress the taker beyond its tested limits of operation.

Releasing pressure once delivery is made and clearing your delivery lines takes a lot of practice and attention. Failure to release pressure in a tanker, then drop that same tanker in a yard can mean a costly physics lesson for you and your company. It goes something like this - as the taker cools and the pressure inside starts to contract - the wall of the tanker can actually implode inward... crushing the tanker’s hoppers. Where does the cooling come into play? From the forced hot air supplied either by your PTO unit on your tractor, or by the supply line supplied by the receiving company. In any event, it’s all compressed air - compressed air is HOT air. Thus the cooling down after use.

For more information on pneumatic tanker operations - see your safety officer at your company.

[bulktanker34]

I can tell you a few horror stories that happened to guys on the job, I did pneumatic bulk trailers (pto driven) for about 51/2 years. not to mention they can be very top heavy annd tend to roll real easy.

[R1Racer99]

That's interesting to read. I usually pull end-dumps but I was trained on the dry bulk tankers at my company a few weeks ago. They sent me with another driver for a day and then put me on my own the next day. They never told me there was anything dangerous about them though. I had one bad clog that kept the pressure way too high but it just spit all the excess air out of the blow-off valve so I don't see how that could be dangerous. I would be curious to know what else is dangerous about it other than messing with the hatch while the trailer is pressurized.

It seems like all you have to do is monitor the gauges and pull some handles to keep the pressure right, I don't see what is so hard about it.

[Big Bill]

I would be curious to know what else is dangerous about it other than messing with the hatch while the trailer is pressurized. It seems like all you have to do is monitor the gauges and pull some handles to keep the pressure right, I don't see what is so hard about it.

There's really nothing hard about it ... as you found out. You paid attention to your work and things went smoothly for you. That's the trick ... as simple as it may seem.

With respect to other dangers .. as you drive, road conditions and other things will bump and jar your hose connections - especially the one that goes directly to the main blow line feed to the tank. Whether hooking to your PTO or the receiver's feed, be careful to check the "snap" connections onto the tank that are around the metal hose coupling at the hose's end. Sometimes they can come lose and when you least expect it ... POW off it comes.

Another consideration is the age and condition of the tanker itself. Depending on what your hauling, hatch-top leaks can have the commodity that your unloading (under pressure) dust out of the top of your tanker and on you. If your carrying a fine powder material ... and its caustic ... you'll be breathing that material, not to mention getting in your eyes and skin. Also, fine powdery materials can leave the top of your tanker dusted with a very slipery surface to walk on. Many dry bulk tankers don't have catwalks with a grid surface to walk accross, so your walking on the curved surface - somewhat, and during a fine misty rain, or frosty weather, that powdery material can mix into a slush that'll send many a driver over the side. On the other hand, it's not unusual to find safety harness and loading and some unloading suppliers that can prevent such accidents.

Again, as is the case, safety minded, learn as you go, be reasoable, know your equipment and its limitations .. and yours, can make the day go by without incident(s).

[outofworkjoe]

Yes I worked for Bulkmatic in the past,we used to unload from rail cars,had to pressurize them to blow off the product,flour,dry ash .And yes this was not an easy job.Bunk tankers are very top heavy and you run all time 80000 gross out,and you cant axle the loads,if your too heavy ,you had to blow it back into the rail car,or go around wt station.

[bulktanker34]

thought this may or may not be prevalent to the topic this is posted in the tanker forum and is a true experience I had unloading flour http://www.truckingboards.com/trucki...rue-story.html