Appeal No. 96-1165
Application 08/060,422
distinct from and apart from the sulfate reduction reactor of Gorin [reactor 42] in a manner
that would impart a patentable distinction from appealed claim 8 and the Gorin patent.
Whether or not the heat values within the “waste by-products” are worth utilizing
in the process is purely a matter of the comparative cost of recovering it and re-using it -
an analysis that is submitted to be well within the skill level of the ordinary engineer
acquainted with this art. Nor has the appellant set forth any surprising or unexpected
advantages to recycling the “waste by-products” back into the sulfate reduction step
inorder [sic, in order] to utilize the residual heat values therein to help provide the
necessary heat for the reduction. Therefore, while it is granted that the Gorin patent does
not “anticipate” this recycle of the waste gas stream as argued by appellant, it is submitted
that this step is obvious to one of ordinary skill in this art even if it is not expressly taught
by Gorin.
Appellant urges that the examiner used hindsight to arrive at his conclusion of obviousness since Gorin fails
to disclose incinerating the waste by-products of the reducing step.
We find ourselves in agreement with appellant. The claims require the incineration of waste by-
product gases and using the heat from the incineration step to heat the sulfate feed. Appellant discloses that
the waste by-products are separated from the metal sulfide in cyclone 24 (specification: p. 9, lines 28-36)
which is similar to Gorin’s cyclone 64. The by-product of the reduction step disclosed by Gorin is reducing
gas (col. 4, lines 1-9) which is designated in Fig. 2 as being surplus fuel gas. While Gorin does not disclose
incinerating this gas, the nature of the gas would have suggested to a person having ordinary skill in the art
that the gas can be incinerated and that heat would be produced therefrom. However, we find no basis
from the teachings of Gorin which would have led a person having ordinary skill in the art to use heat
produced from the incineration of fuel gas to heat the sulfate feed since the feed from boiler 40 to reactor
42 is already heated. Nor do we find any teaching in Kertamus or Wheelock to make up for the deficency
-11-
Page: Previous 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Next
Last modified: November 3, 2007