Interview with Dr. Al Valliant of APS 6/10/2009

    • How did you and Milt get started?
      • Four years earlier, I had started to help clients with problems that required knowledge of Heat Balances, and Heat usage. Since I had done my doctoral research on the heat transfer within Rotary Kilns, it seemed normal to build a bigger computer program to include these results, and the knowledge I had gained in chemical processes. These included the motion of solid and powdered raw materials that were cooked kilns. (an almost horizontal inclined cylinder…refractory lined with a gas burner at its lower, hot discharge end.) The industries we worked in include:
        • a) paper industry
        • b) phosphate industry , 
        • c) coke/ aluminum industry
        • d) petroleum coke Electrode industry… which was cleaner than the mined coal industry’s.

    • What part did Milt play in your work?
      • Milt had assisted the professors at Columbia University in making larger programs. I hired him to write, debug and run the large program, in the evenings after his teaching duties at City University of New York. We worked till 3am Mon/Fri evenings working on the largest computers in NYC to make this larger kiln program. Our client, then, was Great Lakes Carbon (GLC). Later this program was used to help GLC and others improve the product quality, which had deteriorated because (we discovered) petroleum coke was being heated too quickly to 2100 deg. F. in the rotary kilns. Notice that the Kiln is like a black box. It’s too hot to see much…so how do you run it?

    • I understand that you had a business partner. Can you talk a little about him?
      • I and my business partner, Hans Bodlaender, had spent the previous 4 yrs running well-organized energy tests on commercial operations, that consumed much Energy. A single burner would burn 60-90 Million BTU per hour…running 24hrs per day and ~ 300days per year, allowing for maintenance. In West Va., they had closed the elementary and High Schools, one winter, but the burners kept running 24h/day.

    • How did you become familiar with crushing and grinding of minerals?
      • Years of experience on the drafting board, designing and engineering Crushers, grinding Mills with Balls, and Mills with Rods, for the Electrode Industry lead to developing calculation methods for the flows of the resulting particles into storage bins, according to mesh size, to make electrodes for steel, phosphorous, etc. 

    • What did you accomplish by these tests? 
      • Our clients had operating problems trying to reach a capacity that would enable the Engineering dept to turn the plant operation over to the Operations department.

    • What work did you perform for American Cyanamid?
      • Based on the planned tests, for example at American Cyanamid, Ga, we were able to modify the12ft diameter kiln by 300ft of kiln’s internals and change the burner operation to increase the Alumina capacity by 40%. The VP then awarded APS contracts in many parts of the U.S., to improve their operation of other kilns for TiO2, Indirect fired kilns, Spray dryers. The VP was very appreciative. Later, the plant was given a Presidential Flag (white wreath on a light blue field) for its energy savings. This plant is in Andersonville Ga. near Plains Ga., where Pres. Jimmy Carter lives.

    • What communication did you receive from American Cyanamid after you completed the job?
      • It is interesting that later, in 1985, American Cyanamid personnel pointed out that they all would be out of a job unless we could improve the recovery of Alumina from the locally mined Aluminum Sulfate field. We performed a new test, and were able to improve their alumina extraction recovery raising it from 68-71% to 90-92%. We have a very appreciative letter signed by the heads of the plant.

    • Did this save energy?
      • Yes, because they could feed ~20% less material to the kiln system that dried and raised it to over 1400 deg F, in the kiln. This saved over 20% natural gas fuel.

    • Is this service local to southern U.S.? 
      • Although much of our work was in the New Orleans, LA area, and in Texas, we did work for Kaiser Aluminum in Seattle Wa, to calcine coke; In Las Vegas for Lime production; In Los Angeles for a TiO2 kiln that we designed, installed, and tested. Here, too, we were given repeat orders when Cyanamid raised its production requirements, at the Los Angeles, CA plant. They had an Engineer work over 3 months trying. Within 20 hrs at the plant, we met their increased production requirements. Interestingly, their previous small kiln had six large dampers installed within its burner and exhaust system. Using our knowledge of “dampers and valves” APS calculated settings and removed the bottleneck for increased production. See our Web-site article on valves and dampers. Even, plant personnel were not aware that this kiln is one of the few kilns whose refractory lining is not circular. It is octagonal, with the purpose of mixing the rather fine material being processed.

    • What work did you do on other types of kilns?
      • We had done a study of non-circular kilns for Pfizer, in Pennsylvania. They have now built 11 such 8ft “dia” calciners for use in Saint Louis, where we ran a test on an electrically heated kiln and simulated its production of Magnetic Iron Oxide powder for magnetic tapes. The favorable comments of their Chief Development Engineer is quoted in our Web-site. 

    • Have you imparted this information to others than your clients? 
      • I had given a 5 day course on Rotary Kilns through the Center for Professional Advancement, and to some Clients at their field offices. I have given such courses on
        • a) Kiln Operation, Optimization, and Pollution Abatement 
        • b) Statistics of Particle Breakage, 
        • c) Crushing, Grinding and Classification of Particles. 

    • What work did you do in Texas?
      • We ran a plant survey of a 10.5ft by 220ft coke calcining kiln system for high grade petroleum coke in Texas, (Actually this is the 14 coke calcining plant that we have Surveyed). For this client, we included their cooler’s multi-clone efficiency study on the same day as the kiln, incinerator, and cooler. We plotted the cyclone’s efficiency vs. particle size, and reported that 200 lbs/hr could be recovered by improving the cyclone.

    • Al, I understand you also do work in Venezuela? 
      • I received a call from Kaiser Aluminum, Chalmette LA to inform me that three engineers were there, requesting assistance to build a new plant in Venezuela . APS ended up assisting their Caracas office in doing a Coke Calcining Plant including kiln sizing, materials-handling for storage, etc. We designed a Rotary Dryer System. Later we were given a contract by CVG to find 15,000 missing tons of Alumina they had produced. This involved Chemical calculations, flow checking etc. The Vice presidents were sufficiently pleased, to offer APS another job.

    • I understand that you found 300,000 tons of missing Bauxite ore. How did you do this?
      • It was interesting that 300,000 tons of Bauxite were “missing.” A new Vice president and new Chief engineer wanted this material “found” before they would accept responsibility for the bauxite plant. Careful weekly inventories and accounting had been kept for the last 12 years. We measured inventory in piles 40ft high and 300ft long; Developed new density equations vs. height, examined operating procedures, developed new methods for performing Chemical calculations for bauxite consumed in making Alumina, and for measuring barges, conveyor flows, etc. We found the error in inventory of incoming and out-going bauxite. The recording accountants were surprised by our simplifying inventory equation. As an example, we used the inventory of shirts in a haberdashery store. Surprisingly, such inventories need not be made very accurately, since errors cancel out.