teflex industrial oven system
01 | nfpa 86 compliant
02 | reconfigurable heat/exhaust levels
03 | 24 possible configurations
Better thermal performance,
safety & flexibility
Teflon™ PTFE finishing companies with short runs of products can decrease production costs and improve safety by using the TefLex Oven System, a product developed by Precision Quincy in cooperation with Intech, the exclusive distributor of Teflon™ coating products in North America. Teflon™ PTFE coatings have a wide range of VOC levels per gallon, and most coaters need to accommodate a wide range of products (with different sizes and weights) on a daily basis. In response to this reality, Precision Quincy developed a flexible oven system to process short runs of products in a safe and cost effective manner.
The TefLex Oven System is more than just a product: it is a philosophy. Precision Quincy believes in coupling the goals of safety and optimal thermal performance in order to deliver the best cure.
nfpa 86 standards
NFPA 86 requires that ovens processing VOCs must exhaust processed air and replace it with fresh air at a rate of 440 scfm per gallon of solvent. For each scfm of processed air exhausted from an oven, it cost 1.08 btus per degree Fahrenheit above the ambient temperature. For example, an oven exhausting 440scfm at 850f would cost 370,656 btus/hr or 3.7therms. That means that if you are paying $1.25 per therm for natural gas, it will cost $4.625 per hour per batch per gallon of standard solvent that you process through your oven.
To make matters worse, NFPA 86 requires that for every one million btus of burner, an additional 183scfm be used to compensate for the heat loss due to exhausting for solvents. This adds an additional 57,140 btus/hr or 0.57 therms to the heat loss described in the illustration above. This results in an additional cost of $0.7125 per hour per batch per gallon of standard solvent processed through your oven or furnace. The total additional cost then, would be $5.3375 per hour per batch per gallon of standard solvent processed through your oven.
Now let us suppose you are a typical PTFE coating job shop. In the morning you are coating some oil and gas equipment with five gallons of high VOC liquid PTFE primer and your final cure temperature is 850f. That would require that you exhaust 2540scfm of air with a cost of $26.6875 per hour per batch processed in your oven. This is a high cost, but it can be included in the quote for your job. That said, you couldn’t absorb the cost of running your largest VOC job exhaust cost all the time. And more importantly, the cost of running your industrial oven unsafely cannot be quantified. If your typical gallons of solvent per batch number is 0.5 gallons, you are either wasting $24.02 per hour, or running up to 2.5 times the lower explosive limit. Both outcomes are unacceptable.
oven exhaust & heat levels
The TefLex Oven System is a “better way.” With the ability to reconfigure your heat power/ exhaust levels between batches, you can always run at your safest most efficient settings. The TefLex Industrial Oven is modulated to achieve twenty-four possible configurations through the application of three modules: Flash Off, Exhaust Level, and Heat Level.
|
Flash Off |
Exhaust Levels |
Heat Levels |
|
Yes |
1 |
1 |
|
No |
2 |
2 |
|
|
3 |
3 |
|
|
4 |
|
Flash Off Module – In TeffLex Oven System, one selectable module is the Flash Off configuration. NFPA86 dictates the exhaust airflow volume be specified based on maximum temperature. This means an oven rated for one gallon of solvent with a maximum temperature of 850f degrees will have to actually exhaust 193% of what an oven rated for one-gallon solvents with a maximum temperature of 220f degrees will have to exhaust. Why should you care about this? Because when you purchase the Flash Off technology in the TefLex Oven System, you can switch the temperature of your oven between 850f degrees and 220f degrees. The option to safely Flash Off (in this example) improves efficiency by 193%. Once you know that the VOCs level in your product is below your maximum acceptable solvent level in your normal maximum temperature mode, switch over to Normal Mode. The oven will re-purge and you can safely and much more efficiently cure your batch.
Exhaust Levels – In TefLex ovens you can configure your oven with up to four selectable exhaust levels. These are configured in gallons of xylene equivalent most commonly in 0.5 gal increments. You can also think of this as run cost levels. In our illustration above, we were running five gallons of solvent. Assume that we add the Flash Off module to process the five gallons of solvents. Depending on the solvent and process, we are left with one of four solvent levels left in the product: .5 gals, 1.0gals, 1.5gals, or 2.0gals. As stated before we can now choose the most cost effective but safe exhaust level.
|
Exhaust Level |
Run Cost |
Year run cost per shift* |
Shift Year Savings |
|
.5 gals |
$2.31/hr |
$4,620 |
$41,630 |
|
1.0 gals |
$4.62/hr |
$9,240 |
$37,010 |
|
1.5 gals |
$6.94/hr |
$13,800 |
$32,450 |
|
2.0 gals |
$9.25/hr |
$18,500 |
$27,750 |
|
5.0 gals |
$23.125/hr |
$46,250 |
$0 |
*2,000hrs per shift
Heat Levels – The TefLex Oven System also allows you to configure up to three selectable heat levels. These are configured in burner sizes best matched to support your specified exhaust levels and product weights. We discussed earlier the need to increase heat power to compensate for heat losses due to exhausting for VOCs. If we are running an increased exhaust level we need to increase total heat output to compensate. But conversely, as we run in more efficient exhaust levels, it makes sense to decrease total heat output. This is done with multiple burners running in the following configurations.
|
Heat Level |
Small Burner |
Large Burner |
|
Low |
On |
Off |
|
Med |
Off |
On |
|
High |
On |
On |
Contact our sales and engineering professionals to clarify your requirements, get your questions answered, and learn about our oven solutions! Just send us a message or call 302-602-8738.
