Choosing a Powder Booth
I am about to buy a powder booth and I have three quotes with different prices. My boss wants me to buy the least expensive one, but I know that there is more to picking a booth than just price. What are some other factors that affect the value of the different quotes?
This is a difficult question to answer without understanding the goals that you want to achieve with your new booth. However, the fundamentals for evaluation of the proposals are always the same. By starting with a spread sheet, you can look at the various attributes for each of the designs and compare them directly. For a booth evaluation, there are several areas that will affect the performance and value. These include: opening sizes (Are they all the same?); layout (proximity to one another); recovery type (cyclone recovery technology requires higher static pressure performance and horsepower from the fan vs. cartridge recovery technology); recovery volume (When comparing the volume of the system, you need to be sure that when you compare the booths the openings used are consistent square footage from booth to booth. If you divide the cfm capability of the recovery by the square footage, the recovery should be able to produce a minimum of 120 lfpm, or higher, across all of the booth openings, depending on the application); the type, quantity and performance of the filtration system; fan design (belt or direct drive); noise level (typically measured within 3 feet of the unit); construction (stainless steel, engineered plastic, fiberglass, etc., will affect the cost of construction); lighting level (Are lights included, room lighting, side mounted?); controls (What comes standard with the booth, such as reclaim control, level control, triggering, etc?)
These are just a few of the main variables. In most cases, the booth supplier will be happy to provide a breakdown of what exactly they are providing for your evaluation.
Lighting Considerations
We need to add more lighting to our powder booth and application area. What codes or other issues should we consider in the selection and installation of light fixtures in and around the powder booth?
As far as the application area is concerned, the lights that are provided need to be dust-tight fixtures. If it is an environmental room and you put the lights into the ceiling, keeping them flush mount will help with both appearance and cleanliness. If the lights will be suspended, be sure that they are stable and located at least three feet beyond any of the booth openings. If you plan to add lights to the booth cabin, they will usually be placed near the operator openings. Any lights that are placed within three feet of a booth opening must be Class II, Division II, approved light fixtures. As always, when installing light fixtures, be sure to pay attention to how you will be able to access them for service or replacement bulbs.
Three-Minute Color Changes?
We have heard rumors of companies that are able to change colors in a powder system in less than three minutes. Is this true, and how do they do it?
There are a variety of ways to change color quickly with powder. In the case of larger systems utilizing automatic guns, roll on/off configurations with multiple booths are often the best solution. Some of the designs that have been brought in from Europe more recently can provide quick reclaim-to-reclaim times. However, they are typically in the five- to 10-minute range, depending on how dramatic the color change is (red to white or white to black typically take a little longer).
For some customers, the solution can be as simple as not reclaiming the oversprayed material. This can dramatically reduce color change time by limiting the amount of equipment that must be exchanged or cleaned. Spray-to-waste color-change times can easily range from one to five minutes. The ultimate solution comes with combining power-and-free conveyor arrangements where booths may be set up for color ranges (reduces cleaning and set-up time) and the product may then be directed through the use of gates or switches to the appropriate booth. This is still the quickest scenario when full reclaim capability is required.
