Before you can become a full-fledged vacuum nerd like the folks at DuroVac, you’ll need to start with the basics.
Your machine’s duty cycle is determined by the length of time it will be operating. Before you buy a vacuum system, you must match its capabilities with the machine’s expected duty cycle.
As a rule, most of the smaller canister or shop-type vacs use high-speed vacuum producers. These tend to run at a very high rpm, which can reduce the vacuum’s lifespan to as little as 800 hours — or about 18 months, assuming you use your vacuum for about three hours each day.
In today’s market, most vacuum systems over five horsepower are capable of running continuously for years. Their longevity is often determined by various differences in the vacuum producer types. Some will last about five years, and some will last 40 years.
If you’re looking at systems under five horsepower, make sure you buy a model that will stand the test of time.
Your choice of filter system, as well as the filter media, is usually based on the type of dust you work with — that is, whether it’s fine or coarse.
You’ll also want to consider how the filter system will be cleaned. Many filters on portable units are called “shaker type,” which means — just as it sounds — you have to remove and physically shake the filter to clean it.
A few quick notes on shakers:
When it comes to portable vacuums with cartridge type filters, pulse cleaning systems are used most often. Cartridge type filters are very easily clogged and have to be cleaned often. Keep in mind that pulse cleaning is not a continuous method, meaning you have to shut the system down, connect it to plant air, and then manually pulse clean it.
If you have very fine dust in your work areas, we recommend staying away from cartridge systems. Many of them work poorly, and some models even require that you physically remove the cartridge and clean it yourself.
One last note: pay attention to the vacuum’s “can velocity”, which refers to the upward flow of air through a filter cartridge. If the velocity exceeds 125 fpm, the filters will easily clog, and they typically won’t be easy to clean.
How much material storage can you feasibly handle? It all depends on the material your system will vacuum and store. If you are vacuuming steel shot at 375 pcf, then even small storage containers will need to be handled by someone using a machine. On the other hand, if your vacuum material is paper “fluff” at 5 pcf, you’ll want to ask about the best ways to compress that material.
There are many equipment standards, and a variety of optional types of equipment, to help you handle different materials. Ask a few different manufacturers for any ideas they might have.
As the name suggests, portable machines should be easy to move. If you get a unit with larger wheels, they will help you push the unit over uneven floors, cables and mats. Systems with smaller wheels are harder to move around. Some models come equipped to be lifted by forklift or crane, so they can still be moved, even if they are larger in size.
The vacuum system you select should be easy to handle in your working environment. Allow for any odd areas in your plant layout. If you’ll need to move the unit in narrow aisles or through doors, or if you want it to fit inside an elevator, check the weight and dimensions of various units before you buy.
You’ll also want to check the material gauge, and whether the unit is constructed for heavy duty usage. Your vacuum system should be built like a tank — but it should handle much better than a tank in tight quarters.
As a rule, if a system has over two horsepower, it will use three-phase power. Make sure you have distributed appropriate power sources in any areas where you will be using your vacuum unit. If you don’t already have power sources wherever they are needed, you’ll want to budget for that cost in addition to the unit cost. Check to ensure each connection point has a disconnect, because portables only rarely feature disconnects if they are under 20 hp.
Finally, you’ll have to consider what electrical type you’ll need. Many plants require an electrical enclosure that is dust tight (NEMA 4), but many portables only will offer you NEMA 1 or NEMA 12, standard. These are more for general usage, and not sealed.
As a last consideration, you’ll need to look into delivery costs for your unit and read the warranty very carefully. Does it cover the cost to ship you any parts that are defective or need replacing? What specifically does it cover, and how are you reimbursed if you must pay for replacement parts yourself first? After-purchase service levels can make all the difference.