From Start To Finish: Tracing The Operating Components Of Pneumatic Conveyor Systems
Pneumatic conveyor systems sound complicated, but really they are not. If you are interested in learning more about these systems and how they can help move powdered or hard substances along in your factory, the following information will help. It starts at the very beginning, right as something is placed on the conveyor belt.
Neither a Chute Nor a Conveyor Belt
When you think "conveyor," you are probably picturing a belt or chute system. While both of these certainly qualify as conveyor systems, a pneumatic system is very different. It is neither a chute nor a belt. Instead, it is a tube system, much like the ones your bank uses in the drive-thru. Granules, powders or solids are deposited in the start end of the tube. More than one tube can operate simultaneously, so more than one pile of anything can travel to the same destination or to different ones.
Pneumatic Means Air Pressure with Just Air or Nitrogen
After the starting end of the tube is loaded, it is closed so that enough air pressure can build up to force things along. Air in general is enough for powdered substances and light granules. Nitrogen is preferred over compressed air for many reasons, including the fact that it will not contaminate the system with dust particles or poison whatever is being pressed onward through the system. However, if you are just moving dirt or other particles of a similar nature along, compressed air is sufficient.
NO Liquids or Sludges
Hydraulic systems can move liquids and semi-liquids or sludges along, but pneumatic systems cannot. For this reason, it is always important to regularly check pneumatic systems for any sort of liquid or semi-liquid. These substances can build up and block whatever it is you are trying to move through the plant.
Checkpoints and Transfer Points
Undoubtedly, there will be checkpoints and transfer points along the way in your pneumatic system. Here, the substances or items you are moving from one area to the next stop. The system pauses so that employees can make sure everything is moving through correctly.
If the stuff in the tubes has to transfer to another pneumatic line, the transfer point operator flips a switch or pushes a button closing off the straight-ahead path. A side path in the tube system opens. Then the compressed air or nitrogen is once again injected behind the flour, dirt, rocks, or whatever, and the stuff shoots through the side tube in a new direction.
Stuff Continues Along, Stops, and Is Emptied
This process of moving, stopping, and starting keeps the correct pressure of air in the system at every point in the journey. At various points, the system stops and may empty into a vat, a holding tank, or a storage tank. If the stuff in the tubes does not stop to do this, it will travel onward straight to the end of the line, where it it fills a bag, box, or cart.
For instance, say you are moving flour through a modern mill. The flour may be checked along the way to make sure it is not wet and does not have large kernels or granules left, and it then continues to the end to empty into large sacks for commercial use. At each checkpoint or transfer stop, the pneumatic tubes are clear so that the employee can look all around the flour inside without actually touching it. If it passes this visual inspection, it continues on. If it does not, the employee red-flags this batch and asks for a double-check and/or permission to open the sliding drawer on the top of the tube and fish out the potentially offensive or undesirable thing. It may move on after that, or it may be dumped and set aside for inspection.