Induction Heating
Nuclear Airplane
In August 1960 the start up management team consisting of Norm Pinto, John Mesas and Archie Epstien moved to other jobs a new team was assigned to run the operation. The new general manager and chief engineer took away my freedom to act alone and set up strict quality control and purchasing rules.
Just after they arrived a new requirement again turned loose the team of Lona and Metcalf.
Everything produced at the Hazleton plant of Beryllium Corporation was secret so I do not know what we were building for the following project.
I was told that the Atomic Energy Commission had been funded to build a nuclear assist engine for the Air Force that would allow the new fleet of bombers to stay aloft for extended periods.
We had to produce a plate of beryllium 24 inches wide, 60 inches long and 10 inches thick. The distance between the tie rods on the hydraulic presses was 80 inches so the only thing that would fit would be a rectangular vacuum chamber. My solution was an elliptical chamber with an elliptical coil and an elliptical graphite die to press this rectangular part.
At first Joe Lona scratched his head because he forgot how to draw an ellipse let alone calculate the stress. Our chamber supplier had no trouble building the thing to written specifications so we turned him loose.
National Carbon had a slab of graphite 48 inches wide, 40 inches thick and 110 inches long in stock and Harold Weaver, our graphite machining man, had a contact with Allis Chalmers in York, PA that had a contour milling set up.
Ajax Magnethermic declined to bid the special coil so I called Hank Rowan at Inductotherm. His offer was $50,000 if we wanted a guarantee and $20,000 for his best effort. We took the cheaper price.
This was a single acting press and the chamber had a flat bottom. To keep it from buckling when a vacuum was applied we used 30 inches of firebrick in the bottom. The dry out run worked like a charm.
Workers poured the beryllium powder into the strange die and loaded it into the chamber. Everything was set for a normal run late on a Friday evening. I gave the go ahead and arranged to arrive early Saturday morning to observe the critical stage just before the material reached 100% density.
I received an urgent call a couple of hours before my scheduled arrival. The workers were hearing a clicking sound.
When I arrived the clicks were louder and it was clear that the chamber flange was moving in. The whole thing was about to implode due to the outside pressure pushing the chamber wall in the direction of the vacuum. We quickly increased the pressure with argon and closed down the power.
I called Lona and he knew that the chamber was doing what he feared during the design stage. We did not call management over the weekend but Lona called his college professor to come to Hazleton as a consultant.
His quick analysis was that it was almost good enough and without a lot of calculations we needed to increase the flange strength. Lona was able to add strength to the lid and cause it to support the flange at the critical point.
The beryllium part was completed and management knew nothing about the near implosion that could have causes major damage or even death.
Shortly after this project I left the company to become a salesman of induction equipment.
POSTSCRIPT
Archie Epstien continued to work at Beryllium's factory at Reading and was my first customer as a salesman for Ajax Magnethermic. The project was to convert a compound of beryllium to another form. We designed an induction heating system that used a 40-inch graphite cylinder with tongue and groove sections of silicon carbide to keep the carbon from reacting. I would foolishly use this idea on the next NASA job. The mechanical and electrical design worked finebut the heat transfer to the center of the powder product was awful. Archie solved the problem by installing a 4 million BTU gas heater to provide the heat. I think this was the only gas fired induction heater ever built.
Sometime around 1970 I met Archie again in Hazleton where he wanted to construct a small vacuum melting facility for an alloy the Navy wanted for experiments. He wanted to use the elliptical chamber and pumps because it was the only item they could not sell on the used machinery market. I warned him that he would have to beef up the bottom of the chamber.
John Wambold, Hazleton's process engineer was still on the job doing research for the Navy using a pyrolitic graphite furnace and a 36 inch hot isopress press Lona installed before joining me at Cragmet in 1967.
In 1979 I met Archie for the last time when a project I sold him at Consarc would not work. This facility was designed to recover the "zillions" of tungsten carbide projectiles made obsolete by the US Army and NATO. The process was heating these five-pound bullets with zinc to cause the cobalt binder to become liquid. Lona helped me find a large quartz tube for this special little job. In the end it was another of my follies.