Alan George Skyring v Sugar Research Limited

[1986] APO 14

In the Matter of the Patents Act 1952

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In the Matter of Patent Application 520244 in the Name of ALAN GEORGE SKYRING

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In the Matter of Opposition thereto under Section 59 by SUGAR RESEARCH LIMITED

DECISION OF A SUPERVISING EXAMINER OF PATENTS:
Background
         Patent application No. 520244 for an invention entitled "Control System for Crystallizers" is based on a provisional specification lodged on 3 August, 1978 by Alan George Skyring.  The complete specification was lodged on 1 August, 1979 and the application was advertised accepted on 21 January, 1982. Notice of opposition under Section 59 was lodged on 19 July, 1982 by Sugar Research Limited.
         The opponent asked for, and was granted unopposed, a series of extensions of time for serving evidence‑in‑support of the opposition until 19 December, 1982.  The applicant, also after a series of extensions of time for serving his evidence‑in‑answer, served such evidence on 12 November, 1984.  The opponent did not serve evidence‑in‑reply within the time allowed.
         Meanwhile, on 10 January, 1984 the applicant lodged a request under Section 77 to amend the complete specification.  The request was advertised on 2 February, 1984, was not opposed, and allowance thereof was advertised on 14 June, 1984.
         A hearing in relation to the Section 59 opposition was set down for 20 November, 1985.  However, both the applicant through his Patent Attorney, Grant Adams & Co. and the opponent through its Patent Attorney, Phillips, Ormonde &

Fitzpatrick, chose not to attend, relying instead on the evidence on file.
         Although the grounds of opposition stated on the notice are those recited in paragraphs (a) to (i) of sub‑section 59(1), it appears from the evidence that the grounds are limited to those specified in paragraphs (e) and (h); i.e. prior publication and lack of novelty.
The Specification
         The specification, after amendment under Section 77, commences by stating that the invention:

"relates to a control system for equipment for crystallizing solids from a super‑saturated liquid.  The invention is particularly, though not exclusively, applicable to the crystallization of sugar."

It then lists certain disadvantages in relation to known sugar crystallizers such as the difficulty in obtaining "sugar crystals of consistent and controlled size and of good shape".
         There are a number of preferred objects of the invention stated of which the main one appears to be:

"the provision of a control system based on the tying together of the seed crystal feed rate and the primary steam control to the total molasses feed rate as a reference, with equipment to measure the conditions in the crystallizer to vary the actual steam fed into the crystallizer to maintain the optimum conditions."

This is in effect a feed‑forward system with feed back trim to maintain the required settings within the prescribed limits and allows more precise operation using only a single control.
         The specification continues by describing one embodiment of the invention as a continuous crystallizer comprising six compartments; a pre‑
evaporator and five crystallization stages.  For each compartment there is a separate molasses/syrup feed line and steam feed line, with control means for varying the steam flow in relation to the molasses/syrup flow.  This control means comprises a feed‑forward arrangement which sets the steam flow in a set ratio to the molasses/syrup flow into the compartment.  The supersaturation of the massecuite charge is measured by measuring the conductivity of the charge in the corresponding compartment and the steam flow is then adjusted by a feedback arrangement in response to variations in the supersaturation, in order to maintain the supersaturation within a desired range.
         The specification ends with seventeen claims of which claims 1 and 9 are independant; these claims read as follows, the additions made under Section 77 being underlined:

"1.A method for controlling the crystallization of sugar in a supersaturated solution in a crystallizer stage of a continuous crystallizer; including the steps of:

feeding steam into the stage by a "feed forward" operation in a set ratio to the unsaturated molasses feed flow into the stage as a primary control variable;

measuring the supersaturation of the mother liquour in the solution by measuring the confuctivity, under the condition of substantially constant crystal content at the measuring point, and/or the boiling point temperature rise, of the massecuite charge in the supersaturated solution; and

adjusting the steam flow by a "feedback" operation in response to variations in the supersaturation to maintain the supersaturation in a desired range.

9.A control system for controlling the crystallization of sugar in a supersaturated solution in a crystallizer stage of a continuous crystallizer including:

steam feed means into the stage;

unsaturated molasses feed means into the stage;

means to measure the unsaturated molasses feed flow;

means to vary the steam feed means in a "feed forward"

in a set ratio to the unsaturated molasses feed flow;

means to indirectly measure the supersaturation of the motor liquor in the saturated solution in the stage by measuring the conductivity, under the condition of substantially constant crystal content at the measuring point and/or the boiling temperature rise, of the massecuite charge in the supersaturated solution; and

means operable to control the steam feed means in a "feed back" operation in response to variations in the super‑

saturation of the mother liquour."

(Claim 9 corresponds to claim 11 as accepted).
Anticipation
         The evidence‑in‑support includes five declarations together with a number of exhibits.  From this evidence it appears that there are two types of crystallizer used in sugar crystallization processes, i.e. batch and continuous.  The batch crystallizer has been the type most commonly used since about 1813 whereas attempts at constructing and using continuous crystallizers were not successful until 1967 when the Fives Lille Cail Company introduced the continuous operation to refinery operations in Europe.  Exhibit PGW10 illustrates this process.
         The specification is directed to a continuous operation but as accepted claimed not only this type of operation but also the batch pan crystallizing processes.  In the light of the opponents' evidence‑in‑support, the applicant amended the specification to claim only continuous crystallizing operations.  As a consequence of the above amendments, a number of the exhibits submitted by the opponents are no longer relevant.
         The exhibits which appear to be most relevant to the question of novelty of the amended claims are:

(i)Exhibit PGW10, "Continuous Crystallization of Sugar" by Dr. G. Windal published in "The Sugar Journal" September, 1971; and

(ii)Exhibit PGW12, Computer Control of a High Grade Pan ‑ Mossman 1973" by J.A. Frew, R.J. Batterham, R.A. Allaway and P.G. Wright published in the "1974 Proceedings of the Queensland Society of Sugar Cane Technologists".

I consider that some discussion of these exhibits is required.
         The first mentioned exhibit illustrates the continuous crystallization process developed by The Research Centre of Societe Fives Lille‑Cail.  The control system for this process involves the steam rate being specifically related to the feed rate of feed liquor (molasses), i.e. the steam delivery is a determining factor in the feeding of the molasses into the crystallizer.  A regulating valve controls the incoming feed liquor in such a way as to maintain the mother‑liquor supersaturation constant as measured by the boiling point.
         This control system does not have the features defined in claim 1 of the Skyring specification such as feeding steam by a "feed forward" operation in a set ratio to the molasses feed flow and of a "feedback process" to adjust the steam feed in accordance with variations of the supersaturation.
         In his declaration, Peter George Wright has stated in relation to this exhibit that the "idea of regulating the feed proportional to the steam flow, or indeed vice versa, was well known in the early development of continuous pan crystallizers".  I agree that regulating the feed proportional to the steam flow is known but I disagree that the opposite was known as there is no evidence to suggest this from the first exhibit.
         The second exhibit referred to above is directed to a computer control system for a batch pan crystallizer.  Even though it discloses a batch pan crystallizer it appears that the control system has some similarities to that claimed in the Skyring specification and therefore it is pertinent to the question of novelty.
         This paper refers to three suggestions for maintaining the optimum operating conditions, the first of which appears most relevant.  This suggestion is that:

"The feed rate is given and the steam rate is adjusted by a cascade controller, with the supersaturation regulating the steam set point."

Mr. Wright does not elaborate on this in his declaration, and Mr. Skyring has stated that even though the method of operation is similar, there are a number of differences.  I am not entirely sure that these are just not differences in name only.  However, I need only say that the type of control disclosed in this exhibit is a cascaded control rather than a feed forward/feed back control as claimed in the specification.  It appears that the cascaded controller derives its input from the measurement of the supersaturation though this is not entirely clear.  As such, it would appear that the cascaded control is in a way a type of feed back control, and this is in line with the normal use of the term "cascade control"*.  Consequently, there appears to be no disclosure of a
control arrangement having a feed forward nature as claimed in the Skyring specification.

*  "Process Instruments and Controls Handbook" edited by Douglas M. Considine
    which has been available in the Patent Office Library since July 1975.

Conclusion
         The opposition fails on all grounds relied upon, and subject to any appeal which may be lodged, I direct that the application is to proceed to sealing.
         On the matter of costs, the applicant lodged his Section 77 request subsequent to being served with the evidence‑in‑support, and the proposed amendments were allowed and incorporated into the specification on 14 June, 1984.  This matter obviously arose pursuant to the evidence of the opponent. Therefore the applicant should bear all costs up to and including allowance of those amendments, while the opponent should bear any subsequent costs in view of the conclusion I have reached in respect of the opposition.

(J.L. ROVETA)

Patent Attorneys for the applicant : Grant Adams & Co.