Cement Kiln Plant operates with two wet kilns and has a capacity of 675,000 metric tons per year. The kiln exhaust was originally designed to be treated with five and six field electrostatic precipitators (ESPs). Plant currently utilizes waste oil as approximately 15% of their total fuel. The system has an alkali bypass system in place. During early 1992, the plant received many complaints regarding kiln ESP emissions. The solution implemented was an ESP/baghouse hybrid. The first two fields of the ESP were kept intact while the last three fields were gutted and a baghouse cell plate installed. The particulate getting to the filter bags would be very sticky and have approximately 25-27% moisture in the stream.
Collector Designation: Kiln #2 exhaust ESP/ baghouse
Collector Manufacturer: Wheelabrator
Particulate Collected: Kiln dust
Design Airflow Rate: 200,000 acfm
Design Temperature: 374º F
No. Bags/Compartment: 2 Comp. - 425 ea.
Inlet Grain Loading: 10-30 gr/acf 4 Comp. - 325 ea.
Particulate Bulk Density: 60-80 lbs/cf
No. Bags/Collector: 2,150
Cleaning System: Pulse jet
Bag Dimensions: 6.19" dia. x 168.75" long
Bag Material: GORE-TEX® membrane/ TEFLON® B fiberglass fabric(16.8 oz/yd2)
Air-to-Cloth Ratio Design: Gross 4.11:1 Net 4.71:1 to 5.12:1 (depending)
Cage Construction: 2-piece cage, 20-vertical wires, wires, galvanized, 6" horizontal ring spacing and no taper
Date Installed: 1st set – April 1992, 2nd set – March 1996
The complete project (from concept to final commissioning) took place within nine months, costing under two million U.S. dollars. This included obtaining permits, consultant work, and a six-week shut down to complete the retrofit. The second set of bags consistently operate in the 3-4" pressure drop range and clean on demand with 50 psi averaging every six hours. Due to smoky start-ups and some gradual hydrocarbon blinding problems, a gas-fired burner has been installed. The emission results are as follows:
| Outlet Emissions Expressed As | Guarantee from Bag Manufacturer | Permit Requirement | Before Modification | After Modification |
| grains/acf | 0.002 | 0.039(existing)/ 0.019 (new) |
0.020-0.024 | 0.001 |
| grains/ncf (dry) | 0.004 | 0.079 (existing)/ 0.038 (new) |
0.039-0.047 | 0.002 |
| mg/am3 | 7.59 | 94.9(existing)/ 45.5 (new) |
47-57 | 2.39 |
| mg/n m3 | 14.9 | 186.6 (existing)/ 90.7 (new) |
93-112 | 4.8 |
| gram/ton of clinker | 40 | 500 (existing)/ 240 (new) |
250-300 | 12.7 |
Due to expansion/modernization at other sister plants in the region, this plant was shut down during 1997.