(19)
(11) EP 0 317 935 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
03.01.1990 Bulletin 1990/01

(43) Date of publication A2:
31.05.1989 Bulletin 1989/22

(21) Application number: 88119353.6

(22) Date of filing: 21.11.1988
(51) International Patent Classification (IPC)4: B02C 19/18
(84) Designated Contracting States:
BE CH DE ES FR GB IT LI NL

(30) Priority: 25.11.1987 US 125638

(71) Applicant: AIR PRODUCTS AND CHEMICALS, INC.
Allentown, Pennsylvania 18105 (US)

(72) Inventors:
  • Ondush, Andrew Paul
    Catasaqua, PA 18032 (US)
  • Ritter, Richard Donald
    Bath, PA 18014 (US)
  • Anderson, Arthur H.
    Allentown, PA 18104 (US)

(74) Representative: Kador & Partner 
Corneliusstrasse 15
80469 München
80469 München (DE)


(56) References cited: : 
   
       


    (54) Method and apparatus for fine grinding


    (57) A method and apparatus for fine grinding materials normally difficult to grind at ambient temperature, e.g. plastic and elastomeric materials and foodstuffs in a fluid classification type impact mill utilizing liq­uid cryogen to pre-cool the material to be ground, to cool the material and the mill during grinding and to recycle vaporized cryogen from the mill back into the mill as the medium for conveying material to be ground into the mill.







    Search report