BCR: Reducing Plant Costs
A record 722 brick plant managers, supervisors and other industry personnel attended the 49th International Brick Plant Operator's forum September 29-October 1, 2003, in Clemson, S.C. The forum was held in the recently renovated Littlejohn Coliseum on the Clemson University campus, and attendees were impressed with the new venue. Even more impressive, however, was the lineup of papers presented at this year's event. Following are some of the highlights from the 2003 forum.
Fuel-Saving Firing TechniquesAccording to Jim Hopkins of Swindell Dressler International Co., Pittsburgh, Pa., efficient kiln operation is a careful balance between the burners, airflows, scrubbers and setting pattern. If any of these variables are out of line, fuel can be wasted. Implementing pulse firing is an ideal way to save energy, but balancing the burners and maintaining burner efficiencies can also help save fuel. To prevent air infiltration between the kiln cars, plants should use both soft and radiant seals, as well as an exit end brake to keep the train of cars together. Well-maintained sand seals are also important to avoid air leakage. The sand should be round-grained and flowable through 12 mesh, held on 16 mesh. An open setting pattern can also help manufacturers increase heat distribution and push times while saving fuel, and an open deck and girder arrangement can help ensure that enough heat penetrates the load.
For Henry Brick Co. in Selma, Ala., finding the right balance required a number of kiln modifications. According to Dave Davis, supervisor of Plants 1 and 2, the kiln in Plant 1 was built in 1977 by Swindell Dressler and had an original capacity of 42 million standard brick per year. By the late 1990s, the company was pushing about 50 million brick per year through the kiln. In 2000, Henry Brick added a third dryer track and pulse firing, and was able to reduce its fuel consumption to less than 900 BTUs/lb. However, the gas company soon determined that the plant had a faulty gas meter, and when the new meter was installed, the plant discovered it was actually using about 1200 BTUs/lb of fuel. Henry Brick hired
Harrop Industries Inc., Columbus, Ohio, to perform an energy survey, which pinpointed key areas for energy savings. In 2003, the company replaced all of its preheat burners, increased the size of the upper burners in the furnace zone, replaced its combustion blowers, added a loop to the gas header, added a personal computer in its control room, reinsulated the kiln crown, replaced and relocated the crown thermocouples and removed the peep sights in the sidewalls. It also reconfigured the cooling end of the kiln by closing the first relief port and opening the third relief port. This freed the heat to move down the tunnel toward the kiln and made the kiln more efficient. As a result of these retrofits, the plant now produces 58-60 million brick per year with less than 1000 BTUs/lb of fuel.
Boral Bricks' Salisbury, N.C., plant has been able to save more than $2 million by firing with sawdust compared to burning with natural gas or fuel oil. However, according to Brandon Denmon, plant manager of Boral's Henderson, Texas, plant, using sawdust causes greater deterioration on the inner workings of the kiln and mandates more frequent maintenance. Additionally, the proper equipment is needed to dry and size the sawdust to ensure an even burn in the kiln.
"When firing sawdust, put money into equipment that will last. Concrete and rubber stand up to sawdust abrasion better than steel," Denmon said.
Ziegel Gasser Mattoni GmbH S.r.l. in Naz-Sciaves, Italy, has found a more creative way to save energy. The company, which makes hollow brick for structural applications, uses recycled waste materials such as paper and sewage sludge, glass fiber, food production waste, powder coating waste and carbon black to fire its kilns. The company is also successfully using rendered animal fat as fuel. According to Fritz Mödinger, the company spent $20,000 to convert one of its plants from firing with fuel oil to animal fat; however, using animal fat has enabled the plant to reduce emissions so significantly that it no longer needs to run its scrubber. The cost of animal fat is also much lower than the cost of fuel oil. Since an average of 50% of production costs in Italy are from energy, using renewable fuels has enabled the company to significantly increase its profitability.
Energy-Saving Tools and TechnologiesNew tools and technologies are also emerging that can provide a substantial reduction in energy requirements and overall production costs. A roller dryer and roller kiln installed in a roof tile plant in Mexico, for instance, are providing significant energy savings through rapid firing and drying. The system, which was designed by SACMI in Fiorano, Italy, has a capacity of 35,000 roof tile per day. The tile are 450 x 180 mm (18 x 7 in.) in size and weigh 3 kg (6.6 lbs) each. According to Alberto Castelfranco, sales manager, the tile move through three dryer channels and are dried in 90 minutes due to the dryer's extremely uniform ventilation. The tile are then loaded into the kiln and are fired in one hour. With this new system, manufacturing costs are much lower compared to conventional roof tile plants. The system can also be used to dry and fire floor and wall tile.
A new firing concept developed and patented by EISENMANN Corp., Crystal Lake, Ill., uses low-mass kiln cars (1600 lbs/car) with a siliconized silicon carbide (Si/SiC) support system to carry small "packs" of brick through the kiln in a fast firing cycle. The brick are loaded on the supports seven brick long, six packs wide and four bundles high. An automatic load/unload system-similar to the systems used in the dinnerware industry-automatically rolls each level of brick onto and off of the supports. According to Ryan Washburn, manager, Ceramic and Metallurgical Systems, the SiC supports are designed for heavy loads and can handle up to 1050 lbs per level. The 220-ft-long kiln can fire four cars per hour (2688 brick per car) in a 10-hour cycle for a total capacity of 90 million brick per year. The system provides faster heating, which enables companies to reduce dryer and kiln sizes (and therefore capital costs), shorten lead times and possibly lower fluoride emissions; better heat exchange, which increases fuel economy and product quality; enhanced temperature uniformity, which also increases product quality; no pack weight, which reduces breakage and other defects; and lower heat storage, which also reduces fuel consumption. According to Washburn, companies that install this technology can achieve capital, labor and fuel savings, along with higher product quality and reduced scrap.
For plants looking to save energy and increase product quality without investing in new equipment, a new borate additive might provide the answer. According to Michael Austerberry, market development manager for US Borax Inc., borates can increase the compressive strength, chemical durability, freeze/thaw durability and abrasion resistance of the brick while reducing efflorescence, water absorption, and firing and soak times. Tests have shown that the firing temperature for brick containing borates can be reduced by 50 degrees C (90 degrees F), and that the resulting brick are completely freeze-resistant.
To pinpoint energy losses and other potential maintenance problems, some brick plants have begun using thermal imaging. The technology uses an infrared camera to identify areas where heat is escaping from around the kiln door, burners and crown insulation. Thermal imaging also reveals areas of high wear in motors, bearings, kiln or ductwork insulation, plumbing, rolling equipment and other systems. According to Terry Beverly, director of engineering for General Shale Brick, a complete thermal imaging analysis of a plant will typically reveal an average of five minor problems that will need to be checked again at the next scan, three significant problems that need to be taken care of soon, and one or two problems that could cause a complete shutdown of the plant if not repaired immediately. By implementing thermal imaging as part of a regular preventative maintenance program, General Shale's Johnson City, Tenn., plant has already saved over $5000 by preventing shutdowns, and it expects to see additional savings in the future.
According to Rod Evans, manager of technical services for Harrop Industries, a sound preventative maintenance program can provide significant energy savings. Companies should evaluate and document their processes before they start having problems so that they have a comparative standard if problems do arise, Evans said. With kilns and dryers, plants should focus on "vital signs," such as pressures, flow, humidity and temperature. Traveling thermocouples can be used to document the temperature inside the kiln, while hand-held thermocouples can measure temperatures on the exterior of the kiln, under the cars and in cars coming out of the dryer. An optical pyrometer can be used to help train operators to know what the product temperature is by the color of the product so they can easily identify problems. Other tools such as pyrometric shrinkage keys, hand-held manometers, pitot tubes, velometers, relative humidity sensors, moisture regain instruments and oxygen analyzers can also help plants evaluate and document different areas of their drying and firing processes.
Labor-Saving MachineryFor many brick plants, labor costs continue to be a primary concern. As a result, an increasing number of companies are replacing manual processes with automated machinery. In Acme Brick's Millsap, Texas, plant, a one-track monorail was replaced with a two-track dehacker. According to Tracy Bruton, packaging supervisor, the monorail system experienced few electrical and mechanical failures, was easy to clean and had a high level of flexibility, but it also created safety issues, a high employee turnover and variations in package quality. The dehacker, which uses Fanuc robots, has increased production rates and package quality, reduced safety issues and labor costs, and provided better blending of the brick. The key to successfully implementing the new system, Bruton said, was to get the employees involved early and keep them involved.
Henry Brick in Selma, Ala., has also replaced its monorails with automated systems. In 2001, the installation of an automated unloader in Plant 2 enabled the plant to reduce its workweek from 50 to 40 hours while increasing brick production from 25,000 to 31,000 brick per hour (bph). According to Davis Henry, vice president and assistant to the plant manager, Plant 1 was using a crew of 10-and often 12-men on its monorail, but they couldn't keep up with production levels. Additionally, the company was experiencing a high employee turnover, poor attendance, repetitive motion injuries and Occupational Safety and Health Administration (OSHA) problems. The company replaced the monorail in Plant 1 with a Lingl dehacker in March 2003, and is now running with fewer personnel at a workweek less than 40 hours. The dehacker averages 38,000 bph, but is capable of running as high as 51,000 bph.
For Boral Bricks' plants in Augusta, Ga., the problem was slow production rates in a clay preparation facility that supplied ground material for Plants 3 and 4. According to Mike Outlaw, staff engineer, the company upgraded the facility in three phases. In the first phase, it upgraded the crusher and added a dust collector. The second phase consisted of new wiring and safety upgrades, along with a PLC and operator interface that enables operators to easily see what is happening in the plant. In the third phase, the company increased the facility's grinding capacity by installing four Midwestern MEV triple-deck screens with heated top decks to prevent screen blinding. As a result of these modifications, the grinding room is now operating at a level that meets the needs of both manufacturing plants with a minimal amount of overtime-and the company was able to complete the upgrades at 25-30% of the cost of building a new grinding room.
For brick plants evaluating scrubbers, minimal operation and maintenance costs are typically the key concerns. When Belden Brick's Sugarcreek, Ohio, plant needed a scrubber five years ago to control SO2 emissions, the company established a scrubber review committee to thoroughly evaluate its needs and options. After seeing a number of different systems in operation in other brick, carpet and glass fiber manufacturing plants, the company selected a scrubber from McGill Airclean. At $3.2 million, the system was one of the most expensive scrubbers evaluated by the company. However, according to John Jensen, Belden's manager of environmental operations, "You get what you pay for." The company received good service, and the system was commissioned in only 60 days, which was much faster than expected. Additionally, stack tests revealed a 70% SO2 capture rate, which exceeded the required standards, and the system is also relatively easy to operate.
Quality, Safety and the Bottom LineImplementing quality and safety initiatives has helped a number of companies save on production costs. At Belden Brick's Canton, Ohio, plant, becoming certified to the ISO 9001:2000 quality standard enabled the plant to reduce its manufacturing costs from 15.9 cents per brick to 9.02 cents per brick. According to Jim Klein, vice president of administrative services, the company also experienced a more than 5% increase in its A-grade brick from 1994-2002, which enabled it to sell an additional 9.5 million units over that time period. As a result, its total savings was over $15 million, with an additional $1.5 million in savings from reduced waste.
A company-wide safety program implemented at Acme Brick Co. has generated significant savings in minimizing work-related accidents and injuries. According to Terry Davis, Plant ELP675 superintendent, the program is based on the DuPont Safety Training Observation Program (STOP), which advocates 11 principles: 1) all injuries are preventable; 2) safety is everyone's responsibility; 3) management is directly accountable for preventing injuries and occupational illnesses; 4) safety is a condition of employment-training starts on the first day of employment; 5) training is essential to safety; 6) safe work practices should be reinforced, and all unsafe practices corrected promptly; 7) positive reinforcement should be used; 8) it is essential to investigate injuries and incidents with the potential for injury; 9) safety off the job is an important part of the overall safety effort; 10) safety is part of the overall profitability of the company; and 11) people are the most critical element-success depends on the commitment and understanding of the employees.
Editor's NoteThe 2004 "50th Anniversary" International Brick Plant Operator's Forum will be held October 4-6 at the Littlejohn Coliseum in Clemson, S.C. For more information about the forum or to purchase videotapes of the 2003 presentations, contact Denis A. Brosnan, Ph.D., program chairman, National Brick Research Center, P.O. Box 613, Pendleton, SC 2960; (864) 656-1094; fax (864) 656-1095; e-mail email@example.com.
Sidebar: A World-Class ForumWhat if there existed a technical forum for plant operators that covered all of the best ways to operate a plant? Suppose it covered the entire spectrum of plant challenges-from raw materials through forming, drying and firing, complete with case histories. And suppose it provided report cards for vendors and helpful tips on what works, what doesn't and why-wouldn't you want to attend?
This forum does exist, and it is the best technical session that I have ever attended anywhere in the world. It is the International Brick Plant Operator's Forum in Clemson, S.C., and whether you make brick or space shuttle tiles, you would be well advised to go to this forum if you are interested in learning about how a strong industry becomes stronger.
There is a vibrant American ceramic industry here, and it is alive and well. It is born of American ingenuity, and collaboration for industrial gain and improved processes. I was glad to be there, and I was proud of the Americans representing the best in manufacturing technology at this meeting.
--Ralph Ruark, founder and owner of Ruark Engineering, and Senior Technical Editor for Ceramic Industry magazine