(under subclass 233) Apparatus having two or more digesters in operational association.
(1) Note. Patents disclosing plural completely independent digesters are not classified in this subclass. To be here classified the patents must recite some structural interrelationship or interdependency. For example, in this subclass may be found digesters with connections so that cooking gas or liquor may be passed directly from one into the other.
(2) Note. Multiple digesters arranged so that the material to be treated flows serially from one to the other are not provided for in this subclass. For such subject matter see subclasses 243 and 246.
