In re Walch

87 F.2d 511, 24 C.C.P.A. 894, 1937 CCPA LEXIS 51
Court of Customs and Patent Appeals·Decided February 1, 1937·No. No. 3745·Published·Cited by 3 cases

Opinion

LeNeoot, Judge,

delivered the opinion of the court:

This is an appeal from a decision of tire Board of Appeals of the United States Patent Office, affirming a decision of the examiner,, rejecting, for lack of invention over the cited prior art, claim 16-of appellants’ application. Other claims were also involved in said decisions, but this appeal relates only to claim 16, which reads as; follows:

16. The process of separating a mixture of more than two constituents of' which one of the heavier constituents is a relatively free flowing liquid and) the other of the heavier constituents is a relatively viscous material, which.' comprises subjecting the mixture to centrifugal force, effecting separate discharge of the three constituents by so throttling the discharge through which; the two heavier constituents tend to escape as to allow the escape therethrough of only the more free flowing of the two heavier constituents and compel separate outflow of the other heavier constituent.

The references cited are:

Kendrick, 1,293,114, February 4, 1919.
Fawcett, 1,866,638, July 12, 1932.
Crickmer, 1,540,206, June 2, 1925.
MacArthur, 1,591,852, July 6, 1926.
MacArthur, 1,591,853, July 6, 1926.

Certain apparatus claims were allowed by the examiner.

The claimed invention relates to a process to effect the separation of a mixture of three liquids by the use of centrifugal force;- and so adjusting the means of discharge through which the two> heavier constituents tend to escape that only the more free flowing-of such constituents will escape through one discharge outlet, and’, the other heavier constituent through another outlet. The lightest, of the three constituents is discharged in the ordinary manner:■ through outlets close to the rotation center of the centrifugal; b’owli.

[896] According to the specification the specific use of appellants' process is for the separation of a mixture of oil, free sulphuric acid, and acid sludge. .

The patent to Kendrick discloses a centrifugal filtering machine for removing fine particles of matter from liquids, said particles being in a state of suspension in the liquids. In one form shown in the drawings the filter members are made of stacks of thin disks clamped together by nuts on a filter tube. The disks are so close together that the spaces between them may be regarded as of capillary size.

The patent to Fawcett relates to a centrifugal separator for separating grease, “liquor,” and solids. The patent states:

This invention relates to improvements in centrifugal separators and aims at providing a centrifugal separator which will be simple in construction, operate substantially automatically and which will necessitate practically no-cleaning for much longer periods than hitherto usual.
More particularly the invention relates to centrifugal separators of the type in which the solid constituents separated out from the liquor under.■going treatment are discharged through suitable discharge apertures or the like, provided on the machine, for example at the outer periphery of the •casing and at points intermediate between the periphery of the easing and the axis of rotation of the machine.
Centrifugal separators of the foregoing type suffer from the drawbacks either that the discharge apertures for the solid matter ar liable to become choked •or that a substantial proportion of liquid which it is desired to recover, issues along with the solid matter from the discharge apertures.
The present invention aims at overcoming these drawbacks and contemplates broadly supplying separately to the interior of the separator, an additional liquid or liquids in sufficient amounts substantially to prevent the useful liquid undergoing purification from issuing with the solid particles discharged from the machine.
The separator may be supplied with an excess of additional liquid which, during the separation, occupies a zone in the interior of the separator i. e. either in the chamber or adjacent to the nozzle o' located at a certain distance from the axis of the separator. In the vicinity of said zone are provided one or more apertures or the like through which the excess of foreign liquid is adapted to escape.
Said aperture or apertures are made of such small or adjustable dimensions that if an appreciable amount of additional liquid be fed to the separator in excess of that passing through it, then said liquid will form a wall inside the overflow point and thereby increase the pressure of the additional liquid inside the centrifuge. The depth of said wall will depend on the amount of excess liquid supplied. In this way, it is possible to vary the pressures of liquid while the centrifuge is rotating or automatically to compensate alterations of gravity of the liquid undergoing centrifugation or of additional liquid or liquids fed to the separator while the latter is running.

These are the only references which relate to the separation of constituents by the use of centrifugal force.

[897] The patent to Crickmer and the two MacArthur patents were not cited by the examiner, but were cited by the board. They disclose a separation of two liquids of different viscosity by filtering through small capillary openings which serve to hold back the more viscous liquid, permitting only the free flowing liquid to pass through the openings.

The Board of Appeals in its decision stated:

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In re Walch, 87 F.2d 511, 24 C.C.P.A. 894, 1937 CCPA LEXIS 51 (ccpa 1937).

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