History of Electric Induction Heating

This Chapter

Induction Heating
  1. Early work to Salesman
  2. Salesman to entrepreneur
  3. Vacuum furnaces
  4. Henry Rowan, Mars Rocket
  5. Cheston, Cragmet, IRS
  6. Visit Russia, Meet Vera
  7. Around the world, Meet the president
  8. Kramatorsk
  9. Consarc
  10. Consarc UK
  11. Carbon contract
  12. Russians in Scotland
  13. The Embargo is Coming
  14. Embargo and Aftermath
  15. BEPA
  16. After BEPA
  17. Fiber Materials Appeal
  18. Consarc Officials Deny Wrongdoing in Sales to Soviets
  19. Memos from Henry Rowan to Metcalf
  20. Rowland motor patent 1868
  21. Rowland reviews the bids for Niagara Falls power station
  22. Metcalf's father's poem, and Metcalf genealogy
  23. The Peace Treaty of Brest-Litovsk
  24. Problems of Russia's Policy With Respect to China and Japan
  25. History of Ajax Magnethermic
  26. The most important event for Inductotherm
  27. Fright Flight
  28. Black art of carbon production
  29. Polaris Missile
  30. Nuclear Airplane
  31. Nuclear Engine
  32. Molten metal eats through and explodes
  33. Cannon Muskegon Corporation
  34. Metcalf at General Motors Research from April 1955 to Oct 1955
  35. Metcalf pouring superalloy at GE from Oct 1955 to June 1956
  36. Metcalf at Waimet (later Howmet) from June 1956 to July 1957
  37. Black art of carbon production
  38. Project to test NASA hot hydrogen engine
  39. Special Metals Number 9
  40. Metcalf joins Inductotherm group
  41. Device to load materials into a furnace for melting
  42. Bank reneged on a commitment to finance a job in Russia
  43. Inductotherm private airport
  44. NERVA (Nuclear Engine for Rocket Vehicle Application) and all I know about carbon
  45. NERVA Engine Control Rods
  46. same as 383-Nuke.html
  47. Development of Polaris missle
  48. Ajax NASA
  49. Production of carbon fabrics and threads made from rayon
  50. George Houghton, Aerojet Inspector gives Metcalf Rocket history
  51. Rayon to carbon to graphite
  52. Metcalf buys the control division of the Pelton Water Wheel Company
  53. Rowan's account of firing Consarc President
  54. Kama Purchasing Commission, Ukraine
  55. Role of chromium in vacuum melters
  56. ASEA wins contract for isopress
  57. Induction heating to re-refile tank cannon
  58. Hoover-Ugine Company
  59. Letter to Henry Rowan at Inductotherm
  60. John Mortimer in Rancocas
  61. Consarc Board of Directors Meeting
  62. Consarc Board of Directors Meeting
  63. Hillbilly
  64. How to produce Calcarb
  65. Newsday, late 1987
  66. Embargo Regulations
  67. Seizure of Goods
  68. Minutes of Dept of Trade, London
  69. Minutes of ECGD Meeting
  70. Rowan Interview
  71. Bombshell looks like dud
  72. Letter to Hank Rowan
  73. Consarc Board Meeting
  74. Minutes of DTI Meeting, London
  75. Stansted Fluid Power
  76. Minutes of DTI Meeting, 3 Oct 85
  77. Letter to IHI Master Metals

Induction Heating

By James Farol Metcalf

How to Produce Calcarb

The first step is to have a stable and constant feed stock of fibers. Our technology was based upon an expensive precision-cut rayon monofilament fiber about one eight inch long. This fiber is cooked slowly in the absence of air to produce carbon. Rayon is about 45% carbon and 55% water by chemical analysis, and rayon is wet when received by up to 10% water. If it is cooked too fast and in too large a mass the outer portion turns to carbon and the inner part still has water to convert the outer carbon layer to water gas. The yield is down in this case and the fibers are very brittle. This brittle fiber breaks into fine powder, which caused us major problems. In the early days we depended upon carbon cloth scrap made from high strength fibers we purchased from the American scrap market place. This cloth was ground in a mill that produced fines and various lengths. We did not have enough retort capacity to cook rayon because the Scots refused to close down the welding shop to install the equipment.

The second step is to have about 65% of the recycled material of consistent size and quality. A major use at that time was for insulating silicon crystal growing furnaces and a spill box under the furnace. These parts were machined to give a high volume of recycle for future production. We did not have the necessary numerically controlled milling machines to make these products and this work was sent to Rancocas, which left us with a shortfall of recycled material.

The third step is to mix the recycle and fibers with a starch like finely ground resin and the proper amount of water. We had six plastic tanks with mixers that looked like oversized cake mixers you use in the kitchen. The water line that fed the Bellshill factory was too small, so we had to recycle the water during this time. This water and problems with very fine and unfired feed stock caused us fits for several months.

The fourth step is to make a filter cake while slowly sucking the water/fiber mix through a filter screen, leaving the fiber and recycle in a consistent filter cake in the mold. Fines and dirty filter screen cause the filter system to blind and it is necessary to suck harder. We made a few tons of mistakes due to this simple problem. We compounded the error when we used a portion of these failures to recycle directly in the wet phase. The wet recycle caused the dry resin to ball into what Joe Lona called chocolate chip quality. Old filter screens caused a washboard effect on the bottom as the screen wrinkled. Holes in the screen if large enough let all the mix go into the sewer. This happened with regularity in Bellshill in those days.

The fourth step is to dry the filter cake. This step is critical to melt the resin and bond the fibers together. If the cake is allowed to get too hot it will catch fire from the vapors coming from the resin. We had a forty foot container with heat exchanger tubes along the side through which stem was passed. Good drying requires airflow, like a clothing dryer in your home. We did not remember the air flow requirement in the beginning, and we were to find that Scotland's weather is not the best for drying.

The fifth step is firing to at least 700 degrees C. Our retort was overfilled due to lack of installed capacity. This material is an insulator so the middle of the stack was not fired enough.

The final step is firing to at least 1800 degrees C. We had vacuum capability so this step worked fine except when the furnace failed, which was much too often in those days.