Mike Perry recalls Pat White, Buffer tanks and Jets. (circa 1984)

I was the engineer responsible for the construction of the pilot plants built in the ASF Lab. I remember working with Pat White the major driving force on the project. Without Pat I’m sure that Tencel would have remained a laboratory curiosity. I think we started off with a mutual distrust of each other but as our working relationship continued this grew into respect. I admired his abilities very much and his willingness to experiment..

The two things which pleased me most that I designed was the buffer tank and the beam spinning jet.

The buffer tank solved the problem of maintaining a supply of dope to the spinning jet pump at constant pressure with a variable flow coming into it. It also had a system of first in – last out to minimise stagnant volumes of dope within the tank.

With the spinning jet design I realised that the relatively new process of electron beam welding could be used for constructing jets with a rectangular shape. The cleanness and precision of the process meant that the jet plates could be perforated before welding into the body of the holder. A small jet was made first that would fit the standard round holder to try out the principle and check the distortion of the jet plate when subjected to the high pressure when in use. From the data obtained the dimensions of the beam jet with multiple rectangular jet plates  could be worked out. The hole layout and form was done by others. I remember that the jet hole had to be parabolic in section so there was no sudden change in acceleration of the jet stream which would cause the formation of droplets. I used the formula for the design of pressure vessel flanges for the closure of the beam jet. This gave a rather bulky and heavy form. When CEL took over the design for the Grimsby plant they reduced the size of bolts and flange thickness on their design. It leaked under pressure. I’m ashamed to say I felt a little smug! This design of spinning jet was patented.

Dimensions of jet from my notebook probably done at a meeting to discuss requirements,

I hope this diatribe gives you some more background to the Tencel story although perhaps not worthy of a blog.

Cheers

Mike.