US PATENT SUBCLASS 162 / 233
.~ Digester

Current as of: June, 1999
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162 /   HD   PAPER MAKING AND FIBER LIBERATION

232  DF  APPARATUS {22}
233.~ Digester {12}
234  DF  .~.~> With mechanical defibering means {1}
237  DF  .~.~> Continuous
238  DF  .~.~> Automatic control
239  DF  .~.~> With recovery means {1}
241  DF  .~.~> Plural
242  DF  .~.~> Combined
243  DF  .~.~> With pulp agitating or circulating means {1}
245  DF  .~.~> Removable basket or retaining means
246  DF  .~.~> Charging and/or discharging means (including blow pits) {1}
248  DF  .~.~> Forced circulation or percolation of fluid only {1}
250  DF  .~.~> Heating means
251  DF  .~.~> Strainers

DEFINITION

Classification: 162/233

(under subclass 232) Apparatus comprising means for bringing and/or maintaining fiber containing stock material in intimate association with a chemical treating fluid for the purpose of at least partially liberating discrete fibers by destroying nonfibrous bonding material in the stock.

(1) Note. To be classified in this and the indented subclasses, the structures must include more than a mere container in which the reaction occurs. Thus, containers or receptacles of general utility, or having no structure limiting the device to a digester and various subcombinations of general utility are classified in other classes as set forth below under "SEARCH CLASS". The presence of means introducing a treating fluid into the digester structure is sufficient structure for classification in this class (Class 162).

SEE OR SEARCH CLASS

52, Static Structures (e.g., Buildings), appropriate subclasses for a residual in situ erected type material container, particularly

192, 223.1+, 245+, 250+, and 261+.

220, Receptacles, appropriate subclasses for metallic receptacles with or without closure members and see the class definition of that class for the locus of analogous structures.

422, Chemical Apparatus and Process Disinfecting, Deodorizing, Preserving, or Sterilizing, 285, and 307 for cookers and digesters other than those used for liberating or treating fibers.