Outotec Oyj v Commonwealth Scientific and Industrial Research Organisation - [2015] APO 78

IP AUSTRALIA
AUSTRALIAN PATENT OFFICE
Outotec Oyj v Commonwealth Scientific and Industrial Research Organisation [2015] APO 78

Patent Application: 2008253577

Title:Feedwell device

Patent Applicant:                   Commonwealth Scientific and Industrial Research Organisation
Opponent:  Outotec Oyj
Delegate:  R Subbarayan
Decision Date:  24 November 2015
Hearing Date:  2 September 2015, in Canberra

Catchwords:  PATENTS – Opposition to grant of patent under section 59 – whether the claimed invention is novel – whether the claimed invention is inventive – whether the claimed invention is fairly based – none of the grounds made out.

Representation: Patent applicant: None
Opponent:Andrew Lowe of Shelston IP

IP AUSTRALIA
AUSTRALIAN PATENT OFFICE
Patent Application: 2008253577

Title:Feedwell device

Patent Applicant: Commonwealth Scientific and Industrial Research Organisation
Date of Decision: 24 November 2015
DECISION
None of the grounds of opposition has been made out. The claimed invention is novel, inventive and fairly based.
I direct that the application is to proceed to grant subject to any appeal being filed within the relevant period.
Costs awarded against the opponent.
REASONS FOR DECISION
BACKGROUND

Patent application 2008253577 in the name of Commonwealth Scientific and Industrial Research Organisation (the applicant) was filed on 14 May 2008 as a PCT application (PCT/AU2008/000678) and claims an earlier priority date of 17 May 2007. Following examination it was advertised as accepted on 8 March 2012. The grant of the patent has been opposed under s59 of the Patents Act by Outotec Oyj (the opponent). The applicant filed amended claims under s104 on 8 November 2013 following the filing of evidence in support of the opposition. These amended claims were subsequently allowed and are the claims under consideration in this decision. The matter was heard in Canberra on 2 September 2015 with the opponent appearing by telephone. The applicant chose not to appear at the hearing or file written submissions.
EVIDENCE
Evidence in support from the opponent comprises the following:
- Declaration of Peter Lines dated 6 February 2013 with exhibits PL-1 to PL-7 (Lines #1).
- Declaration of Peter Lines dated 23 April 2013 with exhibit PL-8 (Lines #2).
- Declaration of Peter Lines dated 7 August 2013 (Lines #3).
The applicant’s evidence in answer comprising a statutory declaration of Tuan Nguyen, the inventor of the present invention, was filed out of time and the Commissioner refused the applicant’s request for an extension of time. Consequently no regard has been had to the applicant’s evidence in answer in arriving at this decision.
Mr Lines is a consulting engineer providing technical services to industries specialising in solid/liquid separation technology. He has had over 20 years experience in clarifier, thickener and other separation devices primarily from his employment with Dorr-Oliver, Inc. a pioneering company in this field of technology.
THE SPECIFICATION
The specification relates to a separation device for separating solids from a solid-liquid suspension or slurry.
In a number of industrial processes, a suspension of solid particles needs to be separated into supernatant liquid and concentrated solids or sludge. If the purpose is the concentration of solid particles, the process is called “thickening” and if the purpose is to produce clear liquid, the process is called “clarification”. A common process for achieving separation of the solids is sedimentation wherein the solid particles are allowed to settle under gravity. This settling process proceeds more rapidly if the solid particles are of a larger size and consequently in many situations, chemical reagents (known as "coagulants" or "flocculants") are added to the solid suspension to induce bonding between the solid particles to form "agglomerates" which have a larger overall particle size distribution. This process is known in the art variously as "coagulation", "flocculation", "aggregation" or "agglomeration"”.
A device called a feedwell is used to channel the solid-liquid stream into the settling device and is typically designed to (i) act as a baffle to absorb the energy of the solid-liquid stream and thereby assist with gravity settling of the solid particles, (ii) to assist with flocculation of the solid particles and (iii) to distribute the solid-liquid stream exiting the feedwell uniformly across the settling area of the separation device.
According to the specification the “nature of the flow in the feedwell is of critical importance to the performance of industrial separation devices as it is generally here that most of the flocculation occurs. The performance of the feedwell (for instance as measured by the throughput of the solid-liquid stream though the separation device, the clarity of the overflow, or the density of the underflow) directly affects the performance of the separation device proper”. At high flow rates, turbulent flows are present and these tend to hinder the agglomeration or flocculation of the solid particles, with the result that the smaller agglomerates do not effectively separate from the supernatant and are carried out into the overflow. If on the other hand the flow rate is lowered to reduce the turbulent flows, the solid-liquid stream will not be subjected to “sufficient mixing and solids dispersion to result in desirable level of flocculation” before entering the separation device.
The specification further states that “the performance of currently available feedwells is dependent on many factors including the particle size and density of the suspended solids in the solid-liquid stream, the concentration of the suspended solids in the solid-liquid stream, and the flow rate of the solid-liquid stream through the feedwell” and that since these parameters are unlikely to be steady in an industrial setting there is a need for a feedwell that performs well under a range of operating conditions.
This is then followed by a few consistory clauses, two of which mirror the wording of the independent claims 1 and 11.
The specification then provides a detailed description of an embodiment of the feedwell of the present invention. This is best illustrated in figures 1 and 3 that are reproduced below with figure 1 showing the feedwell 6 located inside the separation device and figure 3 being a detailed illustration of the feedwell:
The feedwell 6 which is provided at the top of a separation device (thickener 1) comprises a cylindrical enclosure 10 that is substantially open at its base or bottom end. An upwardly converging flow diverter 12 with an opening 17 at the top 16 is placed within the enclosure and separates the enclosure into a first zone 13 and a second zone 14. A feed stream inlet 15 for the solid-liquid stream is provided in proximity to the base of the flow diverter and is positioned such that the solid-liquid stream enters the first zone 13 of the enclosure in a direction that is tangential with respect to the cylindrical wall of the enclosure. This flow is then directed to flow upwardly in a spiralling manner towards the top 16 by the action of converging walls of the flow diverter. It then passes through the opening 17 in the top of the diverter into the second zone 14 and from there into a settling tank of the separation device.
According to the specification the positioning of the inlet towards the base of the enclosure such that the solid-liquid stream flows upwards in a spiralling manner provides a number of benefits. As the solid-liquid stream circulates in the first zone 13 it “dissipates kinetic energy through frictional forces while also gaining potential energy in the form of hydrostatic head”. It also “prevents short-circuiting of the solid-liquid stream directly to the overflow of the separation device and thus prevents insufficient agglomeration resulting from such flow of the solid-liquid stream substantially directly from the inlet to the second zone. The first zone, and the forced upward flow of the solid-liquid stream through the first zone to the free surface of the liquid within the enclosure, also advantageously allows for a period of disengagement and de-aeration of any air bubbles within the solid-liquid stream”. In addition the surface of the diverter is stated to assist in minimising froth generated by contaminants in the solid-liquid stream from escaping the feedwell and flowing into the separation device proper.
One or more flocculants may be added to the solid-liquid stream to cause agglomeration of the solid particles. This is done with the help of a flocculant sparge which is positioned to introduce flocculant to the non-turbulent flow of the solid-liquid stream in the second zone of the feedwell.
The specification also includes in figures 9-11 results of comparative modelling of the feedwell of the invention against a conventional open feedwell and a feedwell with a shelf over a range of flow rates and these show that the feedwell of the present invention produces superior sized solid particles over a range of flow rates.
The specification ends with 14 claims of which independent claims 1 and 11 are as follows:
1. An apparatus for the flocculation of solid particles in a solid-liquid stream, including
an enclosure, including at least one solid-liquid stream inlet arranged such that the solid-liquid stream has a flow path which enters the enclosure in a direction substantially tangential to an inner surface of the enclosure; and
an upwardly converging flow diverter defining a first zone and a second zone within the enclosure, the solid-liquid stream inlet being positioned in a lower region of the enclosure to provide solid-liquid stream into the first zone at or towards the bottom of the first zone and in proximity to a lower region of the flow diverter, the flow path of the solid-liquid stream spiralling upwardly in the first zone directed by the contours of the upwardly converging flow diverter, the upwardly converging flow diverter having an upper opening for fluid communication between the first zone and the second zone.
11. A separation device including
a settling tank;
at least one feedwell positioned in the tank for receiving a solid-liquid stream, the feedwell having an enclosure including at least one solid-liquid stream inlet arranged such that the solid-liquid stream has a flow path which enters the enclosure in a direction substantially tangential to an inner surface of the enclosure; and
an upwardly converging flow diverter defining a first zone and a second zone within the enclosure, the solid-liquid stream inlet being positioned in a lower region of the enclosure to provide solid-liquid stream into the first zone and in proximity to a lower region of the flow diverter, the flow path of the solid-liquid stream spiralling upwardly in the first zone directed by the contours of the upwardly converging flow diverter the upwardly converging flow diverter having an upper opening for fluid communication between the first zone and the second zone, the first zone having a mixing region above the upper opening for mixing and diluting of the solid-liquid stream with liquid from the settling tank;
the solid-liquid stream from the mixing region exiting the feedwell and settling in the settling tank.
ONUS OF PROOF
The examination request for this patent application was filed prior to 15 April 2013. As a consequence, substantive amendments of the Patents Act 1990 brought about by the Intellectual Property Laws Amendment (Raising the Bar) Act 2012 do not apply to the present application. This includes the amendment to subsection 60 (3A) that allows the Commissioner to refuse a patent application if satisfied on the balance of probabilities that a ground of opposition exists.
Consequently the former standard for opposition proceedings applies and the opponent must establish that it is clear or practically certain that the patent is invalid (F Hoffman La Roche AG v New England Biolabs Inc [2000] FCA 283 at [29], [67]; [2000] FCA 283; 50 IPR 305 at 311, 319; Commissioner of Patents v Sherman [2008] FCAFC 182 at [18], [22]; [2008] FCAFC 182; 79 IPR 426; Genetics Institute Inc v Kirin-Amgen Inc [1999] FCA 742; [1999] 92 FCR 106 at [17] ).
NOVELTY
A claimed invention is deprived of novelty if it has been given to the public before the priority date, either by prior use of a product or process, or by publication of information that equates to the claimed invention (Danisco A/S v Novozymes A/S (No 2) [2011] FCA 282; 91 IPR 209 at [248]). It is well settled that the general test for anticipation or want of novelty is the reverse infringement test (Meyers Taylor Pty Ltd v Vicarr Industries Ltd ([1977] HCA 19; 137 CLR 228 at [19]), and this test is satisfied if the alleged anticipation discloses all of the essential features of the invention as claimed (Nicaro Holdings Pty Ltd v Martin Engineering Co ([1990] FCA 40; 16 IPR 545 at [19]).
To meet this requirement, the prior art must contain “clear and unmistakable directions” to produce the invention as claimed (Pfizer Overseas Pharmaceuticals v Eli Lilley and Company [2005] FCAFC 224; 68 IPR 1 at [314]). However, if the prior publication contains a direction which is capable of being carried out in a manner which would infringe the claimed invention, but would at least as likely be carried out in such a way that would not do so, the invention as claimed will not be anticipated (General Tire & Rubber Co v Firestone Tyre & Rubber Co Ltd [1972] RPC 457 at 485-486; 1A IPR 121 at 138, Novozymes A/S v Danisco A/S [2013] FCAFC 6; 99 IPR 417 at [177]).
In AstraZeneca AB v Apotex Pty Ltd [2014] FCAFC 99 , the full Federal Court held:
"Sufficiency of disclosure is a cardinal anterior requirement in the analysis of whether a prior art document anticipates a claimed invention. It is only after the stage of assessing the sufficiency of disclosure which involves a determination about whether a prior document has "planted the flag" as opposed to having provided merely "a signpost, however clear, upon the road" or, perhaps, something less that the notion of reverse infringement comes into play as the final and resolving step of the required analysis. It is not the first step of the required analysis; nor is it the only step".
The opponent submitted that the claimed invention is not novel in light of the following three documents.
D1: WO 2007/049246 (Folkvang)
D1 discloses a separator tank for separation of well fluid comprising water, oil and gas and is best illustrated in figures 1and 2 which are reproduced below:
It comprises a cylindrical tank 1 with a tangentially arranged inlet 2 for fluid, a first outlet 4 at the top of the tank for less dense fluid such as oil/gas and a second outlet 3 at the bottom of the tank for the denser fluid such as water. A frustoconical shaped wall 5 divides the tank into upper part 6 and lower part 7. The conical wall has a first opening 8 at the upper end to allow communication between the upper and lower parts of the tank and a second opening 10 at the level of the inlet. The second opening is located in such a way that fluid entering through the inlet will rotate about 300° around the upper part of the conical wall before exiting through the second opening 10 into the lower part of the tank. The combination of the tangential inlet and the conical wall is stated to provide for the formation of a vortex flow in both the upper and lower parts of the tank.
While the opponent accepted that the device of D1 is an apparatus for oil-gas-water separation rather than a feedwell for flocculation of solid particles in a solid-liquid stream, they submitted that the apparatus of D1 can be readily applied to this purpose as even D1 states that the process includes the removal of sand which is a solid (page 1, lines 12-14) and that it would be straightforward to add flocculent into the upper part 6 (Lines #3 at 41). They further submitted that the arrangement of the conical wall 5 and the tangential inlet 2 adjacent the lower region of the conical wall 5 would inevitably result in the flow path of the fluid to spiral upwardly and through the opening 8 into the lower part 7.
I do not find the opponent’s submissions persuasive. While there is a brief mention of sand and solid materials in the mixture, D1 is directed to separation of water from the well fluid and not to the separation of the sand. There is no suggestion whatsoever that it can be applied to separation of solids in a solid-liquid stream using flocculation. D1 functions quite differently to the claimed invention. As noted earlier, the water, oil and gas mixture passes from the upper part 6 to the lower part 7 through the second opening 10 and not through the first opening 8. Gas released from the mixture is collected in the upper part 6 of the tank and as the pressure of the gas increases, the gas displaces the liquid mixture in the tank and when the level of the liquid mixture drops below the outlet opening 14 to the first outlet, gas and oil are ejected out of the tank due to gas pressure. This gas pressure would therefore, in my view, prevent the fluid mixture from spiralling upwardly and pass from the upper part to the lower part through the first opening 8. I can find no basis to conclude that the apparatus of D1 would be suitable for separating solids using flocculation or that the solid-liquid mixture would spiral upwardly on the outside of the flow diverter 5.
In my view, D1 does not provide clear and unmistakeable directions to the invention defined in independent claims 1 and 11. The claimed invention is novel over D1.
D2: US 5080792 (McGovern)
D2 also relates to an apparatus for separating fluids such as a mixture of oil and water using a cyclonic action. The opponent relied on the embodiment shown in figure 6 that is reproduced below:
The separator has an enclosure in the form of a tank 66 with a flow diverter in the form of an elongate conduit 22 secured to the bottom of the tank. An inlet conduit 24 extends into the tank and is connected tangentially to the elongate conduit and provides an inlet 26 in the elongate conduit for the oil-water stream. The conduit 22 has a cylindrical base 58 and two conical sections 50, 56 with a conical diffuser 72 at the top providing the outlet 28 of the elongate conduit. The oil-water fluid stream entering tangentially through the inlet is caused to spiral upwardly through the elongate conduit causing the oil to coalesce providing a higher efficiency of separation from the water and on exiting the conduit flows upwardly before it exits through the outlet 70. The denser water on the other hand migrates to the outside of the conduit and on exiting the conduit swirls gently to the bottom of the tank before it exits through the outlet 68.
The opponent submitted that while D2 is directed to separating liquids, Mr Lines has stated that there are no technical barriers that would prevent adapting the arrangement of D2 to the separation of solids and liquids using flocculation.
Again I am not convinced. D2 is directed to separating immiscible fluids by creating a cyclonic or vortex flow within a conduit in order to centrifugally separate the fluids, whereas the spiralling flow in the feedwell of the claimed invention is used to dissipate the kinetic energy of the solid-liquid stream before it enters the second zone where the flocculant is added. In my view, the skilled addressee would not contemplate adapting a cyclonic separator for use as a feedwell of a sedimentation device. Furthermore, in D2 the inlet conduit 24 and inlet 26 are arranged to feed the oil/water mixture to the interior of the elongate conduit 22 and not to the annular space between the tank and the flow diverter as in the claimed invention.
In my view, D2 does not provide clear and unmistakeable directions to the invention defined in independent claims 1 and 11. The claimed invention is novel over D2.
D3: US 4816156 (Brombach)

D3 relates to a hydrodynamic cyclone separator for separating solids from liquids and its disclosure is best illustrated in figure 1 that is reproduced below:
The separator 11 includes an enclosure in the form of a cylindrical jacket 12 and a feed line 20 opens into the jacket in a tangential direction through inlet opening 21. The bottom 13 has a shallow funnel-shaped inside 15 in the centre of which is arranged a sloping outflow hopper 16 that is connected to a outflow line 19. A flow diverter in the form of a distributor 24 is provided in a cover 14 of the jacket and the distributor has a lower region 26 which is funnel-shaped. Immediately outside distributor 24 a circular opening 27 is formed in the cover and forms the overflow for the cyclonic separator. On entering the cylindrical jacket, the solid-liquid mixture is subjected to a rotary movement and heavier solids rolls along the bottom into the outflow hopper. Only the lighter matter and liquids spiral upwardly where the lighter solid matter is trapped by the distributor and sinks downwards. The liquids exit through the overflow 27 into the overflow region 30.
Although the opponent submitted that D3 discloses all of the integers of the independent claims, I am not convinced. While D3 relates to separation of solids from a solid-liquid stream it achieves this by cyclonic action and not by sedimentation. As discussed in relation to D2, I fail to see why the skilled addressee would ever consider this cyclonic separator would be suitable for use as a feedwell in a separator that works by flocculation and sedimentation and where the purpose of the flow diverter is to dissipate energy prior to flocculation of the solid-liquid stream. Furthermore it is clear from figure 1 that the inlet 21 is positioned well below the flow diverter and hence most of the solids in the solid-liquid stream will not be caused to spiral upwardly as required by the claimed invention. In fact most of the solids are separated out in the first zone of the enclosure and only the predominantly liquid stream passes into the second zone 30.
D3 does not disclose all of the integers of independent claims 1 and 11. The claimed invention is novel over D3.
INVENTIVE STEP
Under the provisions of subsections 7(2) and 7 (3) of the Patents Act 1990, an invention is taken to involve an inventive step when compared with the prior art base unless it would have been obvious to a person skilled in the art. The invention must be obvious in the light of the common general knowledge as it existed in the patent area before the priority date, either on its own or together with information in a document, or combination of documents, that the person skilled in the art could, before the priority date of the relevant claim, be reasonably expected to have ascertained, understood and regarded as relevant and, where necessary, combined. Obvious means ‘very plain’ (Lockwood Security Products Pty Ltd v Doric Products Pty Ltd (No 2) [2007] HCA 21 at [ 51] - [52]; (2007) 72 IPR 447 at 461 [51] - [52]).
The test for obviousness was provided by Justice Aicken in Wellcome Foundation Ltd v VR Laboratories (Aust) Pty Ltd [1981] HCA 12 at [45]; 148 CLR 262 at 286 as follows:
"The test is whether the hypothetical addressee faced with the same problem would have taken as a matter of routine whatever steps might have led from the prior art to the invention, whether they be the steps of the inventor or not."
More recently, in Aktiebolaget Hässle v Alphapharm Pty Ltd [2002] HCA 59 at [53]; 212 CLR 411 at [53] the High Court also approved the approach taken in Olin Mathieson Chemical Corporation v Biorex Laboratories Ltd [1970] RPC 157 at 187 in which Graham J had posed the reformulated Cripp's question:
"Would the notional research group at the relevant date, in all the circumstances, directly be led as a matter of course to try [the claimed combination of integers] in the expectation that it might well produce a [useful or desired result]?"
Where the invention lies in a combination of features, the question is whether the combination, not each individual feature, is obvious when compared to the prior art base (Aktiebolaget Hässle v Alphapharm Pty Ltd [2002] HCA 59; 212 CLR 411; Minnesota Mining & Manufacturing Co v Beiersdorf (Australia) Ltd [1980] HCA 9 at [116]; (1980) 144 CLR 253 at 293).
"The claim is for a combination, the interaction between the integers of which is the essential requirement for the presence of an inventive step. It is the selection of the integers out of "perhaps many possibilities" which must be shown to be obvious, bearing in mind that the selection of the integers in which the invention lies can be expected to be a process necessarily involving rejection of other possible integers." (Alphapharm (supra) at [41])
An important consideration is also the impermissible use of hindsight. The High Court in Alphapharm (supra) also warned against the misuse of hindsight noting that the danger of such misuse will be "particularly acute where what is claimed is a new and inventive combination for the interaction of integers, some or all of which are known". In that regard, the court referred with approval to Lord Diplock's comments in Technograph Printed Circuits Ltd v Mills & Rockley (Electronics) Ltd [1972] RPC 346 (at 362):
"Once an invention has been made it is generally possible to postulate a combination of steps by which the inventor might have arrived at the invention that he claims in his specification if he started from something that was already known. But it is only because the invention has been made and has proved successful that it is possible to postulate from what starting point and by what particular combination of steps the inventor could have arrived at his invention. It may be that taken in isolation none of the steps which it is now possible to postulate, if taken in isolation, appears to call for any inventive ingenuity. It is improbable that this reconstruction a posteriori represents the mental process by which the inventor in fact arrived at his invention, but, even if it were, inventive ingenuity lay in perceiving that the final result which it was the object of the inventor to achieve was attainable from the particular starting point and in his selection of the particular combination of steps which would lead to that result."
The High Court in Alphapharm (supra) also noted that “It is important also to remember that in Australia, a "scintilla of inventiveness" will suffice: "no smallness or simplicity will prevent a patent being good"”.
Problem to be addressed
As discussed earlier under “Specification”, the problem that the opposed application seeks to address is to provide a feedwell that will result in desirable level of flocculation under a range of operating conditions and that overcomes the problems of insufficient agglomeration due to turbulent flows at high flow rates and also insufficient mixing and solids dispersion at low flow rates.
D4: WO 03/078021 (Outokumpu)
This is the primary document relied on by the opponent under this ground. It is titled “Dual zone feedwell for a thickener” and describes a separator for a solid-liquid stream similar to the claimed invention. It states that it is directed to overcoming the problem of shortcircuiting of liquid flow from the feedwell and also insufficient residence time within the feedwell for optimum flocculation. I am therefore satisfied that it is a document that the skilled addressee would have ascertained, understood and regarded as relevant. The disclosure of this document is best illustrated in figure 2 that is reproduced below:
This shows a separator 1 with a feedwell 4 located in the top of a thickening tank 5. The feedwell 4 comprises a cylindrical enclosure 4 defining a first chamber 2 having a solid-liquid stream inlet 22 located centrally above the floor 9 of chamber 2. While not explicitly disclosed in the body of the specification, it is clear from figure 1 that the inlet pipe is positioned such that it is tangential to the inner surface of the enclosure. A frustoconical flow diverter 7 is located centrally within the enclosure to define a second chamber 3 within the enclosure. Two agitators 6 are provided within chamber 2 for mixing reagents such as a flocculant into the suspension. It describes the manner of operation as follows:
“In use, the fluid level 21 of tank 5 is located above the level of outlet 11 from chamber 3. The feed liquid enters chamber 2 through an inlet 22 and reagents are added according to a predetermined dosage rate. The volume of slurry in chamber 2 gradually increases, thereby providing sufficient residence time for reaction of the reagents until they overflow into the inner chamber 3. The slurry entering chamber 3 may be dosed with a different reagent to that used in chamber 2, or it may be dosed with more of the same reagent, thus allowing for staged addition. It then flows downwardly under gravity towards the deflection cone 10, which gradually disperses the liquid radially outwardly through the outlet 11 into the surrounding tank.”
The opponent submitted that the only difference between the disclosure of D4 and the claimed invention is that the inlet of D4 is not positioned in a lower region of the chamber 2 such that the solid-liquid stream flows into the first chamber 2 at or towards the bottom of the first chamber and in proximity to a lower region of the flow diverter 7. They however further submitted that it was common general knowledge in the art to locate the feed inlet at the bottom of the feedwell and hence it would have been straightforward to modify the feed inlet of D4 from near the top to the bottom of the enclosure and by doing so the flow path of the solid-liquid stream would spiral upwardly.
Mr Lines in his first declaration which was made before he was shown the opposed application discusses a feedwell and its function in a separation device based on what he knew and what he had observed before 17 May 2007, the priority date of the opposed application. In relation to feed systems for a feedwell he makes the following observations:
“The feed system is typically designed so that distance between the entry point for the feed slurry and the feedwell outlet is maximised. This ensures that there is sufficient residence time for the feed slurry in the feedwell to maximise agglomeration of the heavier particles. It also assists in minimising the kinetic energy of the feed slurry. Where the feedwell outlet is located at the bottom of the feedwell , the feed pipe or inlet would be generally located in the upper half of the feedwell to be located furthest away from the outlet as practicable. An example of this arrangement is illustrated in Annexure PL-2.” (Lines #1 at 24)
“However, not all feed pipes or feed systems were located in the upper half of the feedwell. I am aware of other designs that had feed pipes at locations other than the upper half of the feedwell. Some designs involved locating the feed pipe at or towards the bottom of the feedwell,. Two examples come to mind - the Eimco HRB/HRC clarifier and the Fitch feedwell. The most notable design is the Fitch feedwell developed by Dorr-Oliver and with which I am most familiar with due to my employment. I discuss both the Fitch feedwell and the HRB/HRC clarifier in more detail below.” (Lines #1 at 25)
Mr Line’s evidence is uncontested. I am therefore satisfied that it was known to locate the feed inlet at the bottom of the feedwell in certain feedwells. This fact however does not necessarily lead to the conclusion that the claimed invention is obvious in light of D4 and the common general knowledge. The question that I need to ask is whether the person skilled in the art, would in all the circumstances, directly be led as a matter of course to try to move the inlet of D4 to the bottom of the feedwell in the expectation that it might well perform better under a range of operating conditions including providing for improved agglomeration of solid particles?
In order to answer this question, I think it is important to understand how the feedwell of D4 works. D4 describes the manner of operation as follows:
“In use, the fluid level 21 of tank 5 is located above the level of outlet 11 from chamber 3. The feed liquid enters chamber 2 through an inlet 22 and reagents are added according to a predetermined dosage rate. The volume of slurry in chamber 2 gradually increases, thereby providing sufficient residence time for reaction of the reagents until they overflow into the inner chamber 3. The slurry entering chamber 3 may be dosed with a different reagent to that used in chamber 2, or it may be dosed with more of the same reagent, thus allowing for staged addition. It then flows downwardly under gravity towards the deflection cone 10, which gradually disperses the liquid radially outwardly through the outlet 11 into the surrounding tank.”
The thing that struck me when I read this passage is that despite the fact that the figures appear to show the inlet to be positioned tangential to the inner surface of the cylindrical enclosure, there is no suggestion whatsoever that the feed stream on entering the enclosure is caused to move in a swirling motion around the enclosure. The reference to “the volume of slurry in chamber 2 gradually increases, thereby provided sufficient residence time”, also strongly suggests that the rate of flow of the feed stream into the enclosure is meant to be fairly low and not of sufficient velocity for it to swirl around the frustoconical flow diverter 7 and spiral upwardly. This inference is further supported by the fact that D4 has agitators 6 to mix flocculant into the solid liquid stream rather than use any swirling flow of the feed stream.
Given this inference, even though it was known to place feed inlets in the bottom of feedwells, I am not entirely convinced that the person skilled in the art would have as a matter of course been led to place the inlet of D4 towards the bottom of the enclosure. In the absence of any recognition within D4 for the need to create a spiralling flow, I fail to see why the person skilled in the art would contemplate modifying the teachings of D4 to place the feed inlet near the bottom of the feedwell so that it is in proximity to the lower region of the flow diverter. Even if they would have been so led, I cannot be satisfied that this would inevitably cause the solid-liquid stream to spiral upwardly in the chamber 2 directed by the contours of the frusto-conical flow diverter for the reasons that I have discussed in the preceding paragraph. The placement of the agitators would also in my view, be likely to impede any such upwardly spiralling flow.
I am not satisfied that it is clear or practically certain that invention lacks an inventive step over the teachings of D4 when considered with the common general knowledge.
Lack of inventive step in light of D4 combined with other documents
The opponent also submitted that the claimed invention lacks an inventive step when the disclosure of D4 is combined with any one of the documents D1: WO 2007/049246 (Folkvang), D5: GB 1300724 (Dorr-Oliver), D6: US 4830507 (Bagatto), D7: US 4146471 (Wyness), D8: US3006474 (Fitch), D9: WO 99/37378 (Baker-Hughes), D10: GB 621919 (Candy) and D11: HRB/HRC Clarifier brochure each of which was submitted to disclose a feed inlet located at the bottom of the feedwell. In support of this contention they relied on Mr Line’s third declaration where he states:
“I would consider it to be a straightforward modification of the feedwell in Outokumpu '021 to provide a feed inlet at the bottom of the upstream chamber 2 without much difficulty, based on a combination of any one of these documents with Outokumpu '021. For example, the feed inlet pipe 22 in Outokumpu '021 can be readily replaced with the feed inlet 2 described in Folkvang, the feed inlet in Bagatto or any of the feed inlet arrangements disclosed in Dorr-Oliver, Fitch, Wyness, Baker Hughes, Candy or the HRB/HRC clarifier brochures. (Lines #3 at 144).”
Whilst it is true that all of these documents show a feed inlet for the slurry that is located towards the bottom of the feedwell or separator, it does not follow that the PSA would be motivated to combine this teaching in any one of these documents with the teachings of D4 and be directly led to the claimed invention. The authorities that I have noted earlier have clearly stated that it is the combination that must be shown to be obvious. As stated by Aickin J in Minnesota Mining & Manufacturing (supra):
“In the case of alleged lack of an inventive step the question of making a mosaic must operate (if at all) in a very different matter [to that of novelty]. An allegation of want of inventive step is not made out by saying you may take one or two, or twenty-one or twenty-two, prior publications and then select from them appropriate extracts or pieces of information, which will add up to the invention claimed and so demonstrate that it was obvious. So to proceed is to mistake the nature of an invention and the nature of the objection of obviousness. The question is, is the invention itself obvious, not whether a diligent searcher might find pieces from which there might have been selected the elements which make up the patent. If this were not so, there could never be a valid patent for a new combination of old integers. The proper question is not whether it would have been obvious to the hypothetical addressee who was presented with an ex post facto selection of prior specifications that elements from them could be combined to produce a new product or process. It is rather whether it would have been obvious to a non-inventive skilled worker in the field to select from a possibly very large range of publications the particular combination subsequently chosen by the opponent in the glare of hindsight and also whether it would have been obvious to that worker to select the particular combination of integers from those selected publications. In the case of a combination patent the invention will lie in the selection of integers, a process which will necessarily involve rejection of other possible integers. The prior existence of publications revealing those integers, as separate items, and other possible integers does not of itself make an alleged invention obvious. It is the selection of the integers out of, perhaps many possibilities, which must be shown to be obvious.”
While Mr Lines states that it would be a straightforward modification to change the location of the inlet of D4 from the upper region to the lower region of the enclosure as taught in these other documents, clearly he was presented with an ex post facto selection of prior specifications and then asked whether it would have been a straightforward modification. The proper question is whether this modification would have been obvious to a non-inventive skilled worker in the field to select the integer of the feed inlet being located in the lower region of the feedwell as taught in these documents and combine them with the teachings of D4 to arrive at the claimed invention.
I am not convinced that the answer to this question would be in the affirmative. As discussed earlier, the feedwell of D4 works in a different manner to the claimed invention in that the solid-liquid stream is fed into the feedwell gradually without any great velocity to cause it to swirl upwardly directed by the contour of the conical flow diverter. I am therefore not satisfied that locating the feed inlet at the lower portion of the feedwell is likely to provide any additional benefits or that it would readily suggest itself. Also as noted earlier, any tendency to spiral upwardly is likely to be impeded by the action of the agitators.
I am therefore not satisfied that it clear or practically certain that the non-inventive skilled worker would have in all the circumstances be led to try to place the feed inlet of D4 in the lower portion of the feedwell as taught in the other cited documents in the expectation that it would lead to better agglomeration of the solid particles in the feedwell. This ground of the opposition has not been made out.
Lack of inventive step in light of D1 or D4 combined with D5, D6 or D8

The opponent further submitted that Mr Lines has stated that it would be a routine modification of the feedwell in D5, D6 and D8 to provide a conically shaped flow diverter as described in D1 and D4 and thereby arrive at the claimed invention.
Even if I accept Mr Lines assertion that this would be a routine modification, that does not necessarily make the claimed invention obvious. What Mr Lines fails to state is why the non-inventive skilled person faced with the stated problem would have as a matter of course be led to make such a modification. As noted earlier, where the invention lies in a combination of features, it is the selection of the integers out of "perhaps many possibilities" and their combination which must be shown to be obvious. The evidence of Mr Lines in this regard has been made with the benefit of hindsight and does not satisfy me that such a modification is indeed obvious. This ground has not been made out.
FAIR BASIS
The opponent submitted that claims 12 and 13 travel beyond the disclosure in the specification and are therefore not fairly based. These claims read as follows:
12.The separation device of claim 11, wherein the liquid from the settling tank enters the mixing region by being drawn upwardly through a central region in the second zone.
13. The separation device of claim 12, wherein the liquid from the settling tank flows
counter-currently to the solid-liquid stream in the second zone.
The opponent argued that the Mr Lines has stated that these claims define a well known natural dilution effect that is part of the common general knowledge and as these claims do not define the specific means to achieve the claimed result, they claim all means of achieving the claimed result and therefore travel beyond the disclosure.
In order for a claim to be fairly based, the claim must be consistent with what the specification as a whole describes as the invention and must not travel beyond the subject matter described. The body of the specification on page 16 describes that as the mean particle size distribution increases, settling velocity of the particles around the interior internal surface of the flow diverter in the second zone increases which in turn displaces the liquid and creates an upward flow of liquid from the settling tank through the central region of the second zone and into a mixing region in the first zone. This flow is clearly in the opposite direction to the flow of the solid-liquid stream in the second zone.
In my view, there is clearly sufficient disclosure in page 16 that describes how the claimed results of claims 12 and 13 are achieved. In my view there is a “real and reasonably clear” disclosure of the integers of these claims in the description. The fact that these claims do not specifically describe the settling process that produces this counter flow of liquid from the settling tank does not in my view make these claims travel beyond this disclosure in the description. These claims are fairly based.
CONCLUSION
None of the grounds of opposition has been made out. The claimed invention is novel, inventive and fairly based.
I direct that the application is to proceed to grant subject to any appeal being filed within the relevant period.
COSTS
It is normal practice that costs follow the event. The opposition has been unsuccessful despite the fact that there is no evidence in answer from the applicant and that they did not appear at the hearing. I therefore award costs according to schedule 8 against the opponent Outotec Oyj, noting that in the circumstances there are very few costs available to the applicant. Although I have awarded costs to the applicant, I would like to note that the applicant’s decision not to appear or even file written submissions has not been helpful to these proceedings.
R Subbarayan
Delegate of the Commissioner of Patents