TECH TOPICS: Explosive Fumes
INTRODUCTION
The usual safe practice for installations which are incinerating explosive fumes is to supply sufficient ambient air so that the explosive fume is but a small fraction of the published LEL (Lower Explosion Limit).
With today's rising fuel prices, using a large amount of ambient air as a safety method is very expensive. By reducing the ambient air, and increasing the percent of LEL, significant savings can be realized.
As an example, consider the following typical case:
| Published LEL value of the fume: | 4% | |
| Amount of SCFM of the explosive fume being generated by the process: |
10 SCFM | |
| Amount of ambient air: | 2,500 SCFM | |
| Incineration temperature: | 1,400°F | |
| Process exit temperature: | 100°F | |
| Percentage of LEL process is running at: | 10% | |
| Typical natural gas cost (per million BTU): | $9.50 (per million BTU) | |
| Typical work year (in hours): | 3,000 hours | |
| Allowing for 15% excess air, the burner firing rate would be 6.3 million BTU per hour.
Annual cost=3,000 hours x $9.50/MMBTU x 6.3 MMBTU/hour Annual cost=$179,550. |
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| If ambient air is reduced to 1,250 SCFM, the firing rate at 15% excess air would be 3.2 MMBTU/hr Annual cost=3,000 hours x $9.50/MMBTU x 3.2 MMBTU/hour Annual cost=$91,200. |
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| This is a savings of $88,350 per year! | ||
IS IT SAFE?
With the Conversion Products patent pending ~FUMESAFE~ system it is.
If you are in the planning stage of a thermal or catalytic explosive fume system, the time to decrease the ambient air is now. Conversion Products was involved in the early planning of a coating system for a large pharmaceutical company. Tthe air flow originally proposed by the coater manufacturer was 16,000 scfm.
Using our system as a basis for re-design, the ambient air was reduced to 5,100 scfm. Using the current price of natural gas, and an incineration temperature of 650 °F for a Conversion Products catalytic incineration system, the fuel cost savings was $240,100 per year.
Can we do a retrofit without major changes to your existing system?
The answer is a resounding YES!
Since the present level of ambient air is considered to be safe, a system can be set up using the existing fan but with a motor change that can accommodate a Variable Frequency Drive. Thus, the system will process a significantly smaller amount of ambient air, but the capacity will be there to bring the air flow up to the old value at any time the conditions warrant.
WHAT ABOUT SABOTAGE?
The final documentation for our patent applications was completed after the 9/11 terrorist attack. Any system which is incinerating explosive fumes can be a natural target for terrorists. Our system was designed to detect acts of deliberate sabotage.
We put ourselves in the shoes of a patient saboteur and devised all the possible ways to cause an explosion. From that information, we designed a system to detect any of these acts before the explosive limit was reached.
Since our system can detect sabotage, it can also detect and guard against dangerous operator errors.
Designing or retrofitting an explosive fume incineration system with the Conversion Products ~FUMESAFE~ method not only saves you significant money, but also gives the added protection against operator error and deliberate sabotage.
Why not contact us for a proposal? You have nothing to lose and there is much to be gained.