V4 ° men” 10730)/54 VST] OO

Fal.
October 29, 1959

fa to, Calf furnfa

ca

This day | did discuss with Mr. Torsten Soderluad cf the Servell Inc., centrifuge
manufecturing company the following scheme for axial sediments tion (= ewinsiag bucket
effect). | hed first conceived this scheme on Thursday October 1€, 1959 ond heuve
discussed it with some of my collecgues in the interv..} (Serj; Lelawin; Kornierg;
June Senders among others. )

The eseentisul festure of this propos.1] is the use cf — sinply aschined 'k.ten bowl!
type of centrifuge head in place of the relutively intricute swinging bucket type

of necd. The sample tube is weighted ut the bottow;aa the bowl is percly filled with
= fluid in which the sample tube is flouted. The weighting of the tuke wligns it
along the graviteutionel gradient. In effect, when the bowi is ec resc, the tube's
axis will be verticul; when it is spinning at high speed, the tube exis will be radial
with respect tom thecentrifuge exis. At wll times, therefore, the .xis of the tube
will be et réght angles to the plune of the liquid surface in the tube. und to oI]
isosbestic plunes in the conteined liquid. It will therefore serve the scire function
as the vuriuble inclination of the tube holder in «. swinging-bucket type of centri-
fuge.

The mein udvantuge of this syxmzm system is the low cost und simplicity of manxx
construction of the head. By choice of fluids of proper density cnd viscosity it
should be possible to stabilization the rotating fluid even ut high speeds; also
the buoyent support to the tubes should nuke it pussivle to use yluss «nd other
fragile materials for the tubes at higher speeds thun is now practical. Jt should
alsu be possible tu do uxial gradient centrifugation in much smuller heeds, e.g ,
of the type used in air turbine centrifuges.

Some possible features not shown in the sketch below include:

1} Vanes in the rotor to help transfer ongular momentum to the fluid

2) Restraining cood to the tubes to maintain inclination ut low speeds (when tube
might be pressed bodily against the will of the fluid)

7

3) Profile of the head designed to give comparuble depth of fluid when the neud
is either rotating or at rest. and to allow free incl nation

4) Partitions to keep tubes at opposite sides of head for dynamical ke lonce

5) submergence of entire tube in fmmiscible fluids of two densities.

a F

 

   

  

 

 

  
   
 

Seyi tir amen iO nt ene
A
é ee
POE HE oe memes