Curing inefficiencies - Third Quarter 2009
10 tips for a more efficient cure
TFQ Editorial Staff
With profit margins for tobacco growers already tight, every chance you have to maximize efficiencies—and thus minimize costs—becomes critical to producing the healthiest bottom line possible. Industry experts weigh in on what you can do to make your operation more efficient come curing time.
10. Monitor the heat exchanger
Every time the heat exchanger turns on it costs you money. Better, though, to keep it going for five, 10 or even 20 minutes (depending on all the variables) than to have short blasts of heat coming frequently with the majority of the energy shooting straight up the stack. In fact, Frank Horne Jr., president of BulkTobac, says if you’re not running at least a five-minute cycle, you are definitely inefficient. “It’s the difference between driving a car on the interstate using cruise control and driving stop-and-go in the city,” he says. “You’re going to be more fuel efficient on the highway. You certainly don’t want the heat exchanger running constantly, but the longer you run it, the more you are reaching the highest efficiency possible.”
9. Keep hired labor busy
They say idle hands are the devil’s workshop … well, they don’t do much for your bottom line either! If you have workers on the clock make sure they have something to do. Be sure there is plenty of room to work and that all needed materials are ready to go.
8. Communicate with your buyers
There are many different variables that affect the finished product of cured tobacco, altering its physical appearance, chemical composition and taste. The buyer will have a general idea of what he’s looking for in terms of quality, so communicating with him throughout the process—especially as the season progresses—will help you meet those ideals. “If we have constant communication and know what the buyers want,” Dr. Bob Pearce, tobacco specialist at the University of Kentucky, told TFQ last year, “then we can work together to advise the grower on how to produce a particular style of tobacco.”
7. Check gas (fuel) lines for leaks
Small leaks in gas lines can cost you big bucks. The elements can wreak havoc on your system, so throw some dishwashing detergent and water in a bucket, grab a paint brush and—starting at the tank—go dab some suds on every joint and look for bubbling. “We had a guy who was really mad at us, said the system was terrible because he was using too much gas,” says Horne. “We went down there and did the ‘suds test’ and found he was leaking right from the tank. It’s just something most people don’t think about.”
6. Check the furnace
Make sure the furnace room is sealed well, meaning the floor and ceiling are both free of leaks, and that the air dampers are sealed properly and close completely. Also, if your furnace uses drive belts, make sure the belts and pulleys are in good condition and everything is tightened properly. “Any leaks in the ceiling or floor will draw in outside air and make controlling wet bulb temperatures much more difficult,” says Tom Pharr, president of MarCo Manufacturing Co. “There should be no air escaping when the fan is running, so be sure to replace any deteriorated flooring and make sure all the joints are caulked or otherwise sealed.”
5. Control the damper
The curing process, by definition, is the process of taking moisture out of the tobacco. That moisture, however, stays in the air and must be expelled from the barn with fresh, dry air. That’s where the damper comes in. Because the fresh air to be pumped in is significantly colder than the air already in the barn and needs to be heated, it’s important that you introduce as little fresh air as possible. “Monitoring the air is going to help the fuel efficiency tremendously,” says Horne. “That’s why automatic control systems are so popular. They automatically adjust the damper to provide the minimum amount of air necessary to maintain the wet bulb temperature so you’re not introducing more ‘cold’ outside air than you need. That’s important!”
4. Check the barn for leaks
A winter’s worth of freezes and subsequent thaws can take its toll as materials contract and expand, so it’s vital to check the barn for leaks. Check walls for loose metal on the outside and cracked wood on the inside. Replace damaged materials as needed and make sure all the joints are caulked. Also, the base of the barn should be sealed tightly to the pad and any holes in the barn frame should be sealed. “The best efficiency tip I can give any farmer is to get a smoke bomb and tighten those barns up,” says Horne. “They make smoke bombs just for this that won’t leave any residue. Just put it in a pail and turn on the furnace. Where you see the leaking smoke is where you’ll be leaking hot air.”
3. Check the box seal
Loaded boxes should be placed in the barn with no air leaks between them, ensuring the hot air from the furnace goes through them as opposed to going around and up the wall. Also be sure the barn doors and loading end gaskets are in good shape. “The sealing rubber placed along the inside of the barn to seal between the barn wall and the boxes should be in good condition,” says Pharr. “Also, any torn, damaged or missing door gaskets should be replaced. It’s most important to have an airtight door seal up to at least the highest point of the door where the tobacco is sealed to the door. That is, on box barns it should be to the height of the box-sealing rail, and on rack barns it should be to the top tier.”
2. Uniform airflow
Everything you’ve done up until now was to get you to this point: checking barns for leaks, tuning up the furnace, how you spaced the sticks of your burley crop, etc. Now you need to make sure the moisture is removed from the tobacco in a consistent, even fashion. “The heated air should flow uniformly through all the boxes; through all the tobacco,” says Paul Sumner, tobacco specialist for the University of Georgia.
1. Begin with great tobacco
The tobacco that comes out of the barn at the end can’t be any better than what the grower put in at the beginning. “The first thing you have got to have is good-quality, ripe tobacco to go in the barn for good tobacco to come out,” Sumner told TFQ last year. “You can hardly mess up a barn of tobacco if it is ripe tobacco that goes in.”