Cost Effective Dust Collection For The Composite Manufacturing Industry Part 5
III. SYSTEM TYPE
Now that we have a handle on sizing the system, the next question is; what type of system will be the most cost effective for a given operation? There are two variables which ultimately determine the cost of any dust collection system.
1. How much air volume is required?
2. How much energy (horsepower) will it take to achieve it?
The first step is to do everything possible to minimize the volume of air required to control the dust. This is where the grouping and, perhaps, the use of CCB type enclosures can dramatically reduce the ultimate cost of the system required. The next step is to configure the dust collection components to minimize the amount of energy required to provide the established air volume.
The cost of horsepower is significant. Assuming an average cost for industrial power is approximately 8 cents per kilowatt hour (KwH) and your facility operates a single shift, 5 days a week for 52 weeks, a 5 HP fan will cost $805 per year to operate. If that fan needs to be 30 HP to provide the same volume because of ducting or other installation considerations, the cost to move the same volume of air will be $4,238. It is easy to see how important it is to understand your particular dust collection problem and find the best way to control it.
Locating the dust collector as close as possible to the area it is filtering is one way to reduce the ducting required and, consequently, the fan horsepower. Ducting produces friction or resistance to flow for any fan system and the only way to overcome that is to use a bigger motor. The more ducting needed for your fan, the more horsepower will be required.
Minimizing the area to be filtered is another great way to reduce fan size requirements. If the entire area can’t be located inside a CCB type enclosure, the use of a dropped ceiling is the best method of greatly reducing the fan volume requirement since it reduces the cross section and therefore the total volume of air required. This is one of the easiest and best value facility modifications you can make to maximize dust collection efficiency and minimize energy consumption.
There are many types of basic and hybrid systems available for removal of air borne contamination, but for the purpose of this paper we will address four of the most common:
1. Simple Exhaust Units
2. Source Point Capture
3. Push-Pull Re-circulating
4. Negative Pressure Re-circulating