Is Your Hopper Happy?Saturday, August 1, 2009
What is the make-up of a hopper filtration system? Some can make it sound very sophisticated, while others make light of its role in cleaning. We will talk today about the make-up in modern times while delving into the history of the hopper.
The hopper is a box usually designed in the front of a sweeper. As the machine moves forward the main broom sweeps the debris (large and small) into the lower portion of the hopper. The larger debris such as cups, rocks, wood pieces remain at the lower section, the smaller debris, dust etc. is vacuumed upward into a filter panel where it is captured. The filter is then actuated or shook so the debris is released into a smaller chamber. Both chambers (large and small) are then emptied when the hopper is dumped (usually) into a garbage dumpster and hauled away.
The design of today was very different in years past. My first recollection I have is of a Model 80 Tennant. This was a rider sweeper produced in the late 1960’s. (Ops, I’m giving my age away).
There was no hopper; instead there was just a great big vacuum cleaner bag. When the operator would turn the machine on, the bag would come “alive!” Not! Actually it would, however, absorb great volumes of air like a hot air balloon. Imagine that happening in a 2 to 3 second span, “varooom!”
Of course, the flaw was that if a hole developed, your vacuum was gone, hence a new bag. One could sell quite a few of these vacuum bags and they were not cheap.
In 1975 with the introduction of the Tennant Model 265, that changed everything. A steel hopper was developed. Even though a filter bag was still used, the main job was to capture the fine dust as the panel filters later replaced the filter bags. I personally liked the filter bags.
Even though it was very heavy, it could hold lots of dust and if cleaned every 100 hours or so the bag would last a very long time. A disadvantage was that it was vulnerable to moisture and you definitely would not want to sweep wet surfaces or debris. I will never forget the time a customer stated that his sweeper would no longer pick-up. I asked him when was the last time he emptied the hopper. The customer said, “Empty the what?”
When I saw all the debris crammed inside of this hopper as if one poured wet concrete and put on the lid to let it dry. This hopper had to weigh at least a ton (literally)! The sweeper was struggling to just carry the hopper because it was so heavy.
Now, the Tennant Model 42 HD was made with a filter bag design. This system was good as you are going to get with a sweeper. The perfect design. And it was tough enough for any environment and literally lasted for many years. I know because I sold many of these machines. They were last made in 1989 and one can still see them in the field.
One innovation was the shaker-motor. In the beginning machines such as the Tennant Model 92 had a hand crank. This crank was attached to a beater bar located under the filter bag. One had to crank this in order to loosen the filter bag debris. Today you can push a button that activates the shaker motor, hence, shaking the hopper filter.
Another innovation was the hopper filter. Also known as the panel filter. This makes for an easy change or just to clean the filter.
With this design you can keep better maintenance records of this process, because of its ease. Compared with the filter bag, many do not know when to clean, change or simply did not recognize a dirty filter bag.
Also with the panel filters the OEM Sweeper/Scrubber manufacturers are starting to offer a synthetic material in the panel filter instead of being made of paper. Why is this important? It now means that moisture is no longer your enemy. It also means that the media can be a washable filter.
It does not mean that the media be washed all the time, one usually wants just to “air hose” it clean. The important point here is that the panel filter will no longer fall apart due to moisture. This is a big step for sweepers, indeed. The verdict is still out on the life span between then paper panel filters and synthetic panel filters. I am still seeing results and they are impressive. In many cases, I am seeing life spans of 3 to 4 times that compare to paper.
So, in the future, when asked “paper or plastic” just say synthetic please.
I write this monthly to help you with understanding the sweeper and/or scrubbers and have a little fun with it along the way. Thanks for reading Creamer’s Corner!
Thanks for reading my monthly articles. I hope these series give you the insight into the world of sweeper/scrubbers. If you want to contact me about anything, feel free to e-mail me at email@example.com or call at 800/346-2319.