BCR: State-of-the-Art Dehacking & Unloading
The keynote speaker for the IBPOF was Hans Lingl from Hans Lingl GmbH & Co. KG, of Neu-Ulm, Germany, who discussed “Global Perspectives for the Future of the Brick Industry.” A total of 56 other papers were presented at the forum, along with four short presentations entitled, “Little Things Mean a Lot.” While many of the papers focused on the forum’s main theme of automation in dehacking and unloading, a number of other topics relevant to the brick industry were also covered. Following is a review of some of those presentations.
Dehacking and UnloadingAccording to Ron Daily, plant superintendent of Richtex Plant 4 in Columbia, S.C., 79% of U.S. brick plant use some type of dehacking method, 21% use an automated system, and less than 1% use robotics. However, these statistics will change as more stringent ergonomic regulations are put in place and as it becomes more difficult to find workers willing to perform manual labor. In Canada and Europe, few manual operations exist—almost all operations are automated. The same trend will occur in the U.S.
Richtex Plant 4 is one of the few brick plants using both a dehacker and a monorail, Daily said. The plant was built in 1964 and ’65 as a pipe plant and was converted to brick manufacturing in 1970. At that time, the plant did all of its unloading with just a dehacker. In 1990, a plant expansion led to the installation of a monorail to allow the plant to produce more sizes. Additionally, the dehacker was converted to electronic controls, making it easier to operate. Daily admits that both machines have both good and bad points, and that neither machine is necessarily better than the other, though it is more difficult to find monorail workers than dehacker operators. He also noted that any plant that installs an automatic hacker must make quality brick to ensure that the operation runs smoothly.
At the Acme plant in Sealy, Texas, a state-of-the-art automated Lingl dehacking system was installed in the mid-’80s. According to Wally Chrystal, the plant was originally designed to produce 67 million brick equivalent (BE) per year, but a 1991 expansion provided the plant with the capacity to produce 100 million BE per year. Its products are primarily king-size units for housing, and the demand in the Houston area has been phenomenal since the mid-’80s, Chrystal said. The plant operates seven days a week with three shifts and is very efficient because of the automated system.
According to Jason Williams, Acme’s Elgin, Texas, plant also uses new Lingl equipment. The dehacker holds three kiln cars at a time and can handle 140 brick per hack and 81 hacks per car. The dehacker uses two robots that can handle 40 brick per cycle, or 20,400 pieces per hour. The robots are reliable and are a valuable part of the dehacking machine, Williams said. However, in order for them to work properly, the brick must be flat-set rather than edge-set. This was not a problem at the Elgin facility. The machine is simple, efficient and reliable, and no manual labor is required. Three people run the machine, but one person can run it alone if necessary.
Automation has also significantly reduced labor requirements at Taylor Clay Products’ plant in Salisbury, N.C., said Burt Benfield. The plant started in 1949 and was revamped in 1993. At that time, 100 to 115 people were needed to run the plant in the summer, when production requirements were at their peak. In 1999, the plant installed a Ceric robotic packaging machine, and in December 2000, it purchased an automatic setting machine. The setter, which completely eliminated hand setting, uses Allen Bradley controls and can handle up to 15,000 brick per hour. Both the packaging machine and setter had to be configured to fit in small spaces within the plant. The company currently produces 40 million brick per year with 65 employees year-round. However, Binfield emphasized that installing the automated systems did not result in any employees being fired or laid off. Instead, as employees retired or left the company, they did not have to be replaced.
At Belden Brick Plant 2 in Surgarcreek, Ohio, quality assurance is the only area of production where any person physically has to touch a brick. The rest of the plant is completely automated, primarily with Lingl systems. Three Fanuc M-410 robots are used to unload the brick and can handle up to 120,000 standard brick equivalents in an 81⁄2 hour shift. The robots are also used to help blend the brick. According to process engineer Tim Donaldson, teamwork is an important concept with automated equipment because all of the equipment has to work together to ensure smooth operation. Disadvantages of the robotic systems include the high cost of spare parts, the added training requirements for plant personnel and the technical requirements of maintaining such advanced equipment. However, Donaldson said that the advantages far outweigh the disadvantages. Fewer people are required, fewer ergonomic problems exist, different sizes of brick are more easily handled and the quality is more repeatable. Still, Donaldson cautioned that a 100% commitment on the part of management is necessary to successfully automate a plant because of the challenges that are likely to occur.
According to Christophe Aubertot of Ceric, Inc., robots have become increasingly popular since they were first used in the brick industry in 1997. In North America, a total of 100 robots are currently in operation. Approximately 58% of these are used for setting operations, 33% for dehacking, 5% for cubing and 4% for packaging shapes. Another 22 robots are on order (18 for setting and four for dehacking), and 37 additional orders are anticipated in the next 12 months. In the next five to 10 years, a total of 500 robots might be in operation in North America, Aubertot said.
Kilns and EnergyA four-year cycle of highs and lows tends to occur in gas pricing, said Aubrey Hillard of Southeastern Gas and Power in Charlotte, N.C. The industry is currently in a low period because of the slow economy. However, now is the time to start thinking about long-term plans so that we will be prepared for the next high period, he said.
To avoid fluctuating gas prices, some plants fire with solid fuels, such as coal and sawdust. According to Johnny Brown, General Shale Products’ Kingsport, Tenn., facility uses both. Coal requires a great deal of safety awareness, and both coal and sawdust require testing to ensure that the BTU content is adequate. Moisture content is also critical and can cause firing and handling problems if it is too low or too high. Coal should be at 14,200 BTUs per pound and less than 2% moisture, while sawdust should be at 7,200 BTUs per pound and 5% moisture. The goal is to produce more brick without increasing production costs, and these alternative fuels can cost less than gas and oil, Brown said.
Many brick plants that fire with gas have installed stepped or pulsed firing systems to make their processes more efficient. Acme Brick’s Denton, Texas, plant installed a North American Manufacturing Co. StepFire™ system on one of its three 8-ft-wide, side-fired Harrop tunnel kilns. According to Michael Wheat, the project took 21 days to complete and an additional week to bring the kiln back up to the correct temperature. But once the kiln began production, it fired at a rate of 1190 BTUs per pound compared to the previous 1300 BTUs per pound, and off-grades in the kiln were also reduced by 1⁄2%.
According to Jim Shull of Hanson Brick America-Richtex Brick in Columbia, S.C., energy savings can also be achieved by installing an insulating firebrick (IFB) crown. IFB crowns are much lighter than conventional crowns, and therefore absorb much less of the heat inside the kiln.
While using a kiln’s waste heat to help dry brick can be another way to save energy, it can also cause problems in the brick body. According to Mary Milner, Interstate Brick Co.’s West Jordan, Utah, facility was experiencing a gray-green scum on its products, as well as a haze during firing and flashing. Through a series of tests, the company discovered that hydrochloric acid and other acids were forming in the dryer because of the gases (CO, SO2, NO2, NO, H2S and NOx) that were present in the waste heat. The company solved these problems by increasing the air supply, providing a harder pull on the exhaust, adding pressure to the flash zone, and making minor kiln adjustments. It also added a sugar solution to the pugmill to further reduce scumming.
Problem SolvingNew standards that are being put in place in Europe are likely to boost the use of brick in construction, said Geoff Edgell of CERAM Research, Stoke-on-Trent, England. The standards affect compressive strength (strength will determine compliance), dimensions (individual brick will need to be measured) and bond strength (tabulated values can be used instead of physical tests). These standards are likely to be in place by 2003 and will help ensure the quality of brick products—however, a huge marketing and education effort is needed to make consumers aware of the changes.
According to Harold Newman of Pine Hall Brick Co. in Madison, N.C., brick manufacturers are still getting a bad rap for efflorescence—even though the cause often lies with the installer or consumer. Many de-icing salts and fertilizers contain soluble materials, and when those materials come in contact with water from rain, groundwater or sprinklers, efflorescence is likely to occur. Manufacturers are often called on to help identify the cause and should ask several key questions, including: When was the project constructed? What were the weather conditions during construction? Did the brick come from the manufacturer’s yard or a distributor’s yard? When was the efflorescence first noticed, and has it changed? What was the construction method used, and, in the case of pavers, what basic bedding materials were used? What materials were used in the joint sand/mortar, and what products have been used for cleaning?
New PlantsSeveral new plants have opened within the past couple of years. In 1999, Watsontown Brick Co. in Watsontown, Pa., began construction of a second Lingl plant to expand its product line to buff and gray colored brick. The plant has been in operation for over a year and manufactures 15 different brick sizes. “We built a highly automated yet simple plant that works,” said Bob Sheets.
Triangle Brick Co. in Wadesboro, N.C., has already produced over 40 million brick since the startup of its new plant in February 2001. The plant features a Basic Machinery grinding room, a J.C. Steele hammermill, a Lingl automated setting machine, a PugMaster pugmill, a J.C. Steel 90 extruder, and a Lingl Slug Doubler. It also has a top-fired natural gas kiln with the ability to switch to No. 2 or No. 6 fuel oil.
Both Boren Brick in Monroe, N.C., and Columbus Brick Co. in Columbus, Miss., recently opened new Lingl plants. According to Don Denison of Denison Engineering, Greensboro, N.C., the high efficiency of these plants will enable them to continue operating even in difficult economic times. Low operating costs of less than $30 per thousand brick will enable the plants to compete with virtually any competitive product, Denison said.
Brampton Brick in Toronto, Ontario, Canada, began production in its new Ceric plant in late 2000 and manufactures 60 million premier brick (larger than king size) per year. A special shapes line enables the plant to make a variety of bricks, providing flexibility; and a main line transfer robot and setting robots help ensure efficient production.
In September 2001, Sioux City Brick in Adel, Iowa, also opened a new plant. Built to produce a high-quality red utility brick, the plant uses a Ceric automatic dehacker that both blends and sorts the brick. The plant also features an automatic ASI strapping station with dual Signode strapping heads, and an automatic stretch-wrapping machine from Lantac.
Testing, Dust and RegulationsImplementing useful testing procedures can be challenging for many brick manufacturers. Mike Vickers of Acme Brick in Denton, Texas, said that as many as 75% of all brick companies have experienced significant problems as a result of faulty data. Sensing, collecting, organizing, processing and maintaining are all part of a good data management program. An effective procedure will eliminate user and lab variability and will allow anyone to make useful evaluations, Vickers said, while an ineffective procedure will be inefficient and cumbersome. The key to obtaining valid, accurate data is having an effective procedure that is performed correctly.
Dust is also a problem that many manufacturers face at their mine sites, but dust suppressants can be an effective solution. According to David Johnson, Boral Bricks Inc. in Columbus, Ga., tested three different dust suppressants: magnesium chloride, lignosulfonate and a petroleum resin. The petroleum resin worked the best and was also the most cost-effective, Johnson said. However, he emphasized that for any dust suppressant to work, it must be properly applied and maintained.
The Maximum Achievable Control Technology (MACT) standards, which are intended to limit the HAPs that are released into the environment by requiring emission sources to install controls, such as scrubbers, are supposed to be promulgated by May 15, 2002. However, at this point, it does not appear that the EPA will meet this deadline. According to Terry Schimmel of Boral Bricks Inc., Columbus, Ga., failure of the rule to be promulgated by this deadline means that state-by-state decisions would be made instead, and each plant would likely need to undergo a MACT review. The BIA task force continues to work with the EPA lead office to ensure that any final standards that are passed are reasonable.
Brick ManufacturingSpecial shapes have always held a love/hate relationship with manufacturers, said Howard Tysinger of J.C. Steele & Sons, Statesville, N.C. The market loves them, but manufacturers hate how difficult they are to produce. Still, many plants are looking at increasing production of special shapes to meet market demand. These manufacturers can either run the additional shapes on their current J.C. Steele 90 extruder with the use of die bases and shaper caps, or they can add a separate shapes extrusion line, Tysinger said. The former will be low in capital cost but will add downtime to the main production line. In contrast, a separate shapes extrusion line requires a large capital investment but allows the main production line to continue running efficiently without interruptions. The right solution depends on an individual plant’s needs.
Plants that have to flash their products might want to try the new “applied” flashes instead. Unlike actual flashing, which is done inside the kiln and can be difficult to control, these new coatings can be applied at any time in the production cycle, offer controlled repeatability and flash density, improve emissions control and brick output, and eliminate waste, said J. Alan Petefish from The Prince Manufacturing Co., Quincy, Ill. The color performance and control is similar to existing flashed product lines, and applied flashes also offer brick manufacturers the opportunity to extend their color palettes. There is an equipment expense and a modest material expense involved with using applied flashes; however, significant savings in production can be achieved compared to traditional flashing.