This is the basic information that most every buyer will prefer to have in front of them when they purchase an industrial vacuum. This stuff will help give you an idea of what to read through in order to make an educated choice as a buyer.
1.1 Duty Cycle
The duty cycle of a machine is determined by the length of time it will be operating. It’s imperative that you match the capabilities of the vacuum system you’re looking to buy with the duty cycle that the machine will be expected to have.
As a rule, most of the smaller canister or shop-type vacs use high speed vacuum producers, which run at about 20,000-25,000 rpm! This is a death wish for the vacuum, since it will cause the carbon brushes or bearings to wear out in as few as 800 hours. There are some high-rpm vacuums of European design that you may be able to run for 2,500 hours, but you’ll pay dearly for the extra hours.
This means if you only use your vacuum for about three hours each day, one of the typical standard canister vacuums will not usually last longer than 18 months or so.
Most vacuum systems on today’s market that are over five horsepower use motors that are capable of running continuously for years. There are various differences in the vacuum producer types that will be a determining factor in their longevity. Some will last for five years or so, and some will last for 40 years. This will be fully discussed in our Central Vacuum section, under Types of Exhausters.
If you’re looking at systems that are smaller than five horsepower, be sure that you buy a model that won’t self-destruct if you would like your vacuum system to last.
1.2 The Filter System
The Filter System is something that you might not pay much attention to, up front. But it will get a lot of attention after you begin using a vacuum system! You may be reading this information now because of the time that is wasted when you have to clean and maintain the filters on your current system. There’s an easier way to use a vacuum system without a lot of downtime…
The filter is one system that you’ll have to choose, among several various types of filter media. This is usually based on how fine the dust is that you work with.
Consider how the filter system will be cleaned, too. Many filters on portable units are called “shaker type”. For some models, especially canister vacuums, this means just what it sounds like… you have to remove the filter and physically shake it!
Larger vacuum systems with shakers utilize various methods to accomplish the cleaning of the filters. Side to side shaking is generally accepted as being more effective than up and down shaking, but it’s more difficult to accomplish. Some vacuums have cleaning systems that are almost worthless, but others work extremely well. Feel free to ask us for more details.
Shaker filters will need you to power off your system before you can clean the bags. Unless the filters can remain working efficiently until your material canister is full, you’ll need to periodically turn off the system and clean the filters. This is the number one complaint from owners of vacuum systems, if the system is under-sized and uses a shaker design, since it causes the most down time. A cleaning system can work automatically, either by automatically shutting down the system, shaking and the restarting the system or by using pulse jet cleaning or reverse air. We only know of one portable vacuum that still uses reverse air filter cleaning, and it isn’t automatic. The technology of reverse air cleaning is older in terms of today’s technology, but it’s effective in some systems.
Pulse jet cleaning uses dust collecting technology that allows the filter to be cleaned while the vacuum system is running. It seems like it would be a useful way to clean filters, but in actuality it’s not that useful if your system has limited storage capacity. Plus, you have to connect it to plant air.
The majority of the time, pulse cleaning systems are used in portable vacuums with cartridge type filters. This is due to the fact that these filters are very easily clogged, and they have to be cleaned quite often. Many cartridge units are marketed as having pulse cleaning, but that’s a misleading “fact”, since it’s not a continuous type of cleaning. You have to shut the system down, connect it to plant air and then manually pulse clean it.
In our knowledgeable opinion, if you have very fine dust in your work areas, don’t look to cartridge systems to keep the areas clean. At least get references from people who use a model before you buy – some cartridge systems do work well, but many more don’t. Some vacuum manufacturers’ models even require that you physically take the cartridge out, and clean it however you can!
You also need to be aware of “can velocity” in a vacuum. This refers to the upward flow of air through a filter cartridge. It should not exceed 125 fpm, or you may wonder how it works – until it doesn’t. If can velocity is too high for the unit, the filters will be easily clogged and they usually aren’t easy to clean, either.
1.3 Storage Requirement
It’s important for you to determine how much material storage will be feasible for you to 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 many different materials. Ask a few different manufacturers for any ideas they might have.
Portable machines, even by name, need to 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 work with. Some models come equipped to be lifted by forklift or crane, so they can still be moved, even if they are larger in size.
1.5 Frame Size
The vacuum system you select should be easily handled in your working environment. Allow for any odd areas your plant layout may have. If you’ll need to move the unit in narrow aisles or through doors, or if you want yours to fit in 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 in a way that gives it heavy duty usage. You’ll be sending your vacuum system out into your company’s war zone, so to speak, and you’ll want it to be built like a tank – but to handle better in tight quarters than most tanks could.
As a rule, if a system has over two horsepower, it will use three phase power. Be sure that 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, Be sure that 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 costs for delivery for your unit, and what kind of warranty you get. Check over any warranty very carefully. Will it pay for 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? You would be amazed, and not always in a good way, at the various service levels after you make your purchase.