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Flow
Research Evaluation Diagnostics - FRED Ltd ________________________ Indicative illustration items of past promotional
pitches soliciting sales for sensibly scienced sounder solutions |
Flow Research Evaluation
Diagnostics - FRED Ltd Associate Company Tel:0121 471 4149 Fax:0121 471 4149Email: Neale@Thomas.net
Web: Neale.Thomas.net Founded 1988 as a creative company for perspective
projects principally on maritime military gizmos (acoustodynamic angles on
material mixtures) but also furnishing flow-focused formulations to a
considerable clientele of SMEs and MNCs. A decade ago FRED won four
consecutive SMART Awards for a pair of environmentally friendlier industrial
technologies (wind-driven sewage treatment, low-dose/drift agricultural
spraying), both still patented but still only crawling toward
commercialisation. NT's agenda now extends to mechanistic modelling of
motivational determinants of innovation impact! |
Hairy Roots for
process biotechnology of plant products
PROFILE Natural products from cropped or collected
plants abound as and are key to mainstream and fringe pharmaceuticals, also as
flavourings and fragrances. Their market niche is protected by complexity of
molecular conformation which renders synthesis unprofitable, combined with the
confidence conveyed in “natural” which reduces regulatory resistance as well as
instilling customer confidence. For a decade from the early 80s much expensive
endeavour was given to evaluating innovative strategies for carrying these
natural biosynthetic processes into the laboratory via plant cell suspension
culture in bioreactors. In the absence of demonstrated prospective commercial
viability, hardening hearts of the government funding agencies arrested these
activities in the early 90s and only a handful of groups were able to persevere
with laying the essential foundations. Fortunately in this select band because
of corporate concern by a tobacco major on prospects for production of nicotine
in smoking substitutes (sprays, patches, gums), my attention was redirected
from cell suspensions to hairy roots as more promising avenue to stable
synthesis, also for precursors affording product access by post-processing.
Hairy roots are generated naturally by plants after opportunistic infection by
the bacterium A. rhizogenes which is
accompanied by gene insertion triggering growth of fibrous hairs. In the wild
there is a natural synergy between the bacterium and host plant, notably for
the plant as enhanced nutrient exchange via increased root mass which retains
the plant genome and so can support reversion to the uninfected state. In the
laboratory there is a major advantage of improved stability of hairy roots
excised from infected plants as compared with cells in culture whose notorious
unpredictability and mediocre productivity was the main cause of failure in
this bioprocessing strategy as a practicable prospect. Plants vary considerably
in their resistance to infection but many of most interest for alkaloid
products are susceptible and often very substantially so in the presence of a suitably
virulent strain of the bacterium. Screening of plant lines for susceptibility
combined with productivity is a crucial element.
POSITION Familiarisation with transformed Nicotiana species in benchtop studies in
the early 90s was followed by demonstration of an innovative integrated
bio-reactor / separator system conceived to cope with the special demands of
root-mass culture and configured by analogy with tube-bundling principle
employed in nuclear power technology. Thus rather than incur uncertain and
expensive verification in scale-up, the strategy here is to validate at a
suitably selected standard size with the desired total capacity achieved by
multiple units operationally phased so as to provide essentially continuous
production accommodating necessary biomass renewal by growth from inocula
multiply ported into each tube at the required interval. Although in-house
evaluation has extended to confident repeatable operation of an 8L unit, there
remains a need to identify the optimal maximum volume recognising that internal
wire-framing will be needed to support the root mass against weight compaction
in very big tubes - compaction being undesirable not just for risk of tissue
damage but for possible obstruction of gravity-drained liquid nutrient which is
drip-fed from the top against an upflowing air stream for respiration. In
production phase, the liquid stream is recirculated via an extraction column
or, more precisely, this phase is alternated between product generation and
elicitation using appropriate media compositions. The same approach has
subsequently been adopted by other leading groups around the world which lends
confidence in our claimed capability but equally represents a lost opportunity
for commercial exploitation via appropriate IPR protection - the latter sought
via academic avenues of my present affiliation but rejected for reasons unclear
then and since (ignorance apart).
PURPOSE Although patenting opportunities for the
configuration have been lost, the system alone is by no means the key to
commercial viability. Indeed, until very recently our best estimate based on a
crude calculation indicated a shortfall factor two in price / cost ratio for
the most promising products presently accessed. These comprise a family of
tropane alkaloids from Datura stramonium of
pharmaceutical value for their anticholinergic and antispasmodic activity -
especially in the treatment of nerve gas poisoning. However, the impending
closedown of our activity (the last one in this area in the UK) prompted a
desperate final fling to close the gap and it worked! Specifically, by
incorporating an additional ingredient into our soup of biophysicochemical
co-factors the previously attainable performance has been boosted by a factor
16 and a further factor 2 appears accessible. This single element
overwhelmingly outweighs all of the other “tricks” compounded over the past 5
years or so and truly represents a “Eureka” event in this arena. Factor 16 gain
here means factor 8 as our revised notional price / cost ratio for these
products and is comparable with expectations on domestic “gizmo” products so it
deserves at least cursory consideration for commercialisation. Prospects for
patenting are unclear and I am not prepared to release any indication of what
is involved without a contractual commitment to proceed with exploitation on
confirmation of the claimed capability. In other words, prospective partners
must be persuaded that the market exists and that the margins are indeed as currently
claimed (factor 2 short) and on this basis make the commitment to
commercialisation subject only to confirmation that the further factor 16 is
achievable as a demonstration. Crucially, our “Eureka event” is seemingly
generic and the factor 16 improvement over previously reported best performance
would suffice to bring many products within commercial viability locus.
Water Treatment
as process integration in package plant
PROFILE Bio-oxidation for quality restoration of wastewater requires energy for aeration and agitation. In nature the energy derives from wind transferred via waves which sustain gas transfer, especially at higher speeds with wave-breaking and bubble entrainment. Photosynthetic bioprocesses also contribute via algae but are not central to the compass of current consideration. Essential is recognition that oxygen deficits associated with natural detritus from decaying biology are (usually) substantially less than encountered with waste waters derived from human activities including not just as domestic sewage but also from intensive husbandry and industrial operations, the latter often with additional burdens of bio-resistive organic and metallic constituents. Of course, virtually all such substances occur naturally and so nature has assuredly evolved organisms that can metabolise virtually all, if not directly then at least adaptively and often co-operatively - for example, via cycling between aerobes, anaerobes and facultative microbes. However, the strength of modern effluent streams from intensified activities frequently defeats nature’s capacity for exploitation via digestion and assimilation as witnessed in eutrophication of soils by leachates from landfill sites, of inland waters by sewage discharges and even of coastal waters by run-off of agricultural fertilisers. A common fashionable deception is the belief that by extending “natural capacity” for digestion we can accommodate our excesses - viz engineered reedbeds and wetlands. Truth is that process intensification is prerequisite for acceptable mediation of concentrated effluents because the limiting factor most often is oxygen transfer for maintenance of aerobic conditions in the treatment environment. Reeds are undeniably sustained by photosynthetic metabolism but wetland performance is effectively dictated by prevailing windiness rather than synergetic exchange via rhizomes. Arguably reeds provide no more than a passive substrate to support active microbial biofilms and in this respect they can actually suppress aerobic activity by inhibiting dissolution of oxygen in absorbing wind energy and thereby reducing agitation of the water surface. The health hazard posed by failed wetlands is now recognised especially Stateside where the technology was first introduced on substantial scales and we have brought to the EPA’s attention a simple scaling analysis by which performance expectation can be gauged largely in terms of site windiness, plus the prospect of mediation by retrofitted intensification zones powered by turbine-captured wind energy for augmented aeration by agitation. Process intensification and integration are the key ingredients to resolution of this emerging concern about the growing danger.
POSITION Familiarisation with water treatment
issues and remedies stems from my campus company’s receipt of technology
innovation awards from the UK government’s DTI SMART scheme for SMEs, in
particular awards received in the early 90s for concept evaluation of
wind-driven treatment systems. Rules-of-thumb suffice to show that 6m/s ambient
mean wind with 50% energy extraction efficiency furnishes enough power (40W/m2)
to sustain agitation aeration (1kgO/kWh) to a depth of 1m for aerobic digestion
(40mgO/Lh; x5 saturation per hour) of standard strength screened domestic
sewage (400mgO/L deficit) in 10h providing the capture area matches the
footprint area of the treatment tank. Standard strength here is roughly x400
the oxygen deficit of biological detritus in natural streams and intriguingly
x400 is also roughly the ratio of wind power available above the ground to that
absorbed as friction at the surface. These seductive scaling similarities
equally indicate that x400 footprint area is required for wind-blown lagoons
and wetlands (1m depth typically) of equivalent capacity to that secured from
wind-powered plant for which compactness is comparable to that of
conventionally powered plant. It explains why reedbeds are so expensive even
compared with conventional tank treatment systems (80+p/m3 against 20p/m3),
also why recent efforts have concerned their re-engineering to incorporate
forced aeration by plunging or pumped aeration, the former conceived as being
“natural” though of course sacrificed gravitational head is energetically
equivalent. Captured wind power costing about £2k/kW pays back in 5 years on
mains delivery charged at 5p/kWh (8kh/y) and 10 years is often adopted as
effective working lifetime for package plant., indicating commercial viability
break-point at £4k/kW for wind-turbine capital and maintenance (and repairs),
this ignoring the cost for provision of mains or diesel power which may be
substantial at remote rural locations. Note that the 10h treatment time adopted
as basis here implies ~100L/pop (250L/d) so a guideline cost of tanking plus
internals for agitation aeration roughly £200/m3 (power density above) provides
baseline cost £20/pop or 2p/m3 over 10-year lifetime (100m3/y) or x10 margin
commercial viability on market expectation price of 20p/m3. However, the basis
of 6m/s ambient wind is certainly conservative for the UK where it ranges
upwards from 6m/s to 12+m/s in Scotland and recalling that power goes as speed
cubed, an ambient of 10m/s provides for x4+ increased delivery corresponding to
x2 reduction in sizing of both turbine and tanking, likewise also treatment
cost reduced to 1p/m3 or just 5% of the expectation price. Whichever way this
cake is cut, the margins are massive enough to excite the most sceptical
speculator if the basis is believable - and it is, really!.
PURPOSE Although wind-powered plant was key to our conceptualisation in winning and executing the SMART project, hard-headed commercialism since dictated the turbine be shelved for plausibility with sector specialists in the UK. Crucially however, it was because of constraints imposed in configuring the process to accommodate vagaries in energy supply from wind that the resulting rugged integration of sequentially staged but intimately interfaced anaerobic and aerobic zones gave us an edge in bioprocess performance and resilience. In addition to novel blending of fixed and free biofilm supports within a single circular tank, we also won margin from a unique system for agitation aeration by snorkelling suction configured originally for versatile operability over the widely varying power supply. The principle here owes much to my experience of bubbly flow fundamentals, exploiting vorticity to induce suction for both induction and retention of bubbles within the working volume. Performance to date compares with industry expectations accompanied by economic advantages of simplicity in fabrication and operation, importantly also with scope for substantial enhancement in staying ahead of copycat competition. The unit is now trialling with a major UK utility company and has been laboratory demonstrated to precipitate metals in 24h from pH3 acidified waters. What it needs is business backing by professional punters with vision to endorse its exploitation in all of the avenues identified above.
Agrochemical
Spraying halving both wind-drift and drop-size
PROFILE Multiple crop applications of insecticides and
herbicides are long-established as a crucial component of agricultural
intensification for economic production of food. The public may yearn for
“natural” practices exploiting predator-prey relationships to reduce crop
losses but the harsh reality is that seasonal uncertainties in the weather and
hence population balances give rise to major excursions in efficacy which is
inevitably reflected in variabilities of product quality and availability that
the public won’t tolerate. Whilst genetic engineering offers the prospect of
favourably shifting the productivity equilibrium there is considerable consumer
resistance to these “unnatural” practices even compared with spraying which is
certainly disliked but is tolerated by the public presumably because it is such
a long-established and familiar procedure - akin to an uneasy alliance between
silently hostile neighbours. Recognising this sensitivity, the agrochemical
industry has moved toward reduced applications of supposedly safer products,
recently even to the extent of evaluating such fancy schemes as GPS navigated
patch spraying using automated pattern recognition to discriminate weed
clusters! However, the underlying challenge remains improved utilisation of the
introduced chemical and wind-drift is still the performance-limiting factor for
timeliness in spraying whilst drop-size is still the performance-limiting
factor for biological uptake per unit volume of application. Halving of both is
way beyond the scope of existing spraying systems to the extent that such
capability delivered at current expectations on cost will certainly pose
substantial implications for sector resistance by the chemical companies as
well as the spraying system suppliers. Anticipating such reaction precautionary
protection has been pursued as patent applications lodged throughout Europe as
well as the US and Japan, coverage for which the cost is ample evidence of our
commitment and confidence in both efficacy and novelty of the physical
principles in our innovation.
POSITION Familiarisation with agrochemical
spraying issues stems from my campus company’s receipt of technology innovation
awards from the UK government’s DTI SMART scheme for SMEs, in particular awards
received in the early 90s for concept evaluation of systems utilising
externally introduced air as activating agent for dynamical control in droplet
generation and translation. Long-established methods utilising pressurised
hydraulic nozzles deployed on a towed boom still dominate the market but are
under increasing threat from recent advances manifested in air-assisted
approaches in which air is either injected internally to produce hollow drops
on nozzle exit or externally to shroud the drops during transit to target. The
former allegedly affords lower liquid use without the drift penalty incurred by
hydraulic nozzles operating with reduced drop-size whilst the latter employs
such nozzles on the understanding that drift should be inhibited by the
co-flowing air. Of course, unassisted hydraulic nozzles also deliver droplets
within a co-flowing air-stream induced
by momentum exchange and the volumetric flowrate of this entrained air far
exceeds the volumetric flowrate of liquid - maybe upwards of x1000, approaching
the flowrates of low-pressure “bulking” air employed in curtain sprayers (not a
coincidence of course). On the other hand, air-injection nozzles employ much
smaller quantities (x10 or so) but at high pressure as needed to generate a
bubbly fluid composition on nozzle exit. Curtain sprayers thus sport clumsy
fans and boom bags whereas “bubble sprayers” incorporate compact compressors
but incur a practical penalty on power coupling and maintenance. The niche we
sought to occupy neatly resides logarithmically midway between these extremes,
quite literally with typical air flowrate ratio about x100 at pressures which
can be met by a standard blower, much more compact than fan and bag assembly
and more rugged than a compressor - not to mention cheaper on capital and
maintenance as crucial considerations for the notoriously tight-fisted farming
community. Essential distinctions are also reflected in the physical principles
insofar as our concept is premised on the notion that it makes no sense to
battle with air against high-pressure water inside the nozzle nor to battle
with air against wind once the drops are on their way. The real window of
opportunity exists in using air to forge the spray from issuing liquid outside
the nozzle, more especially by playing a high-speed sheet on the breaking edge
of the liquid fan. The aim (and achievement) was to excite a resonant interplay
of stretching and bending motions where the film is thinnest and therefore most
susceptible both for drop-size reduction and for drop capture and retention in
the intensely vortical airflow induced by cyclical separation at the flapping
salient edge of the fan. The mechanism is distinctive for its audible tone as
droplet laden vortices transit at kHz frequencies, sufficiently high as to have
no adverse implications for the footprint of such cluster spraying in terms of
crop-coverage. Independent trials by Silsoe Institute have confirmed the
central claim.
PURPOSE Air-activated enhancement of agrochemical
spraying has been demonstrated feasible and favourable. The technology is
commercially competitive, comprising simply a set of air-sheet nozzles plus
attachment clips and a standard blower (<1 barg, 5kW) plus air deployment
lines. Pricing in line with market expectations for such products is projected
to provide customer payback in 1 year on chemical saving compared with
hydraulic nozzles, as against 2-3 years for air-injection and air-curtain
sprayers. However, the margin would be modest (as it is for existing products)
and maybe a premium price policy would be plausible always recognising the
reluctance of this sector to spend unless a subsidy is on offer. Depending on
infrastructure envisaged available for the activity, maybe lease-hire is an
option here. Finally, please note that there is a generic gizmo on offer here
and it’s always been my feeling that there may be much more scope for megamoney
from applications in combustion, in firefighting, also in flash cooling and
scrubbing, the first and last especially topical for control on HC/NOX and VOC
emissions.
Viper = Vapour Implosive Pulsation For Extreme Reactivity
CONTEXT
Power density PD is the dominant determinant for accessibility to extreme
reactivity whether it is procured from mechanical, thermal, chemical, acoustic,
laser or nuclear drivers. Typical PDs encountered in the process industry
utilising shaft-stirred tanks range up to kW/L or so. Typical PDs from
combustion manifested in prime movers like engines deliver maybe up to MW/L.
More exotic controlled sources associated with power ultrasound and flash
boiling apparently range up to GW/L but access to TW/L is normally viewed as
being the province of uncontrolled explosions rather than sustained operations.
Explosions apart, the trend to higher PD is broadly accompanied by smaller
spatial and temporal scales such that the energy exchange (EE = PD x size x duration)
is substantially smaller in power transducers (say to 100mm and 100ms) than in
processing tanks (say to 10+m and 10+h). Intriguingly, bursting soap bubbles
represent MW/L PD sources though with extremely modest EE being delivered via
100 micron droplets expelled at 10 m/s or so. Worth remarking perhaps that
meltdown and / or explosion at Three Mile Island was probably averted only by
the extremely high heat transfer rates achieved in ultramicroscale flash
boiling associated with bubbles on micron / ms scales presumably at number
densities akin to those in emulsions
CONNECTION
There is military and civil interest in power ultrasound respectively for sonar
and process intensification, also for boosting the performance of diffusion
limited exchanges in heat and mass transfer at boundaries. Perhaps the major
obstacle here relates to lifetime limitations for the active heads of such
transducers subjected to bombardment by microjets from collapsing cavitation
bubbles, akin to the erosion-corrosion pitting incurred on surfaces
experiencing high-speed translation motions or flows in excess of 25 m/s or so.
This drawback is a powerful driver for consideration of configurations offering
remote induction of cavitation such as are employed in so-called single bubble
sonochemical applications where the aim is to achieve
"super-symmetry" in the excitation of forced oscillations by the
target. Under these conditions it has been found that an environment can be
induced exhibiting extremes ranging to 10kK and kbar or so, albeit prevailing
for duratons of only picos or so as extremely rapid spikes within forcing
periods of micros or so (?). I believe the jury is still out between candidate
explanations offered in terms of spherically convergent shock waves and
ionisation effects (?) as most persuasive explanation but the former is
certainly appealing if only for its more straightforward simplicity to a
continuum dynamicist. Beyond obvious opportunities for exploring extremely fast
chemistry / combustion (?) I understand that there has been much interest at
Los Alamos Laboratory regarding the potential here for fusion induction as
alternative to induction by laser pulsing. Probably the main point here is that
exceptionally extreme PDs are delivered in these circumstances but on such
small spatio-temporal scales as to be of limited obvious potential as an
alternative to multibubble ultrasound for the military and civil applications
considered here.
CONJECTURE
Water hammer is widely recognised as a common cause of considerable mechanical
damage associated with the impact of shock waves on vulnerable surfaces.
Calculation schemes are well established and have been widely employed for such
relevances but almost exclusively in terms of plane wave formulations or at
most as gradually-varied modulations. Recent manifestations of this interest
have been concerned with acoustic propagation in bubbly fluids, most often as
confined fields in shock-tubes but also with recent interest in free fields of
bubble plumes for purposes of protection against shocks as a weapons
counter-measure and for transmission of acoustic signals in low frequency
underwater communications. The essential point here is that intensification
opportunities for planar propagation only really arise in connection with
boundary impingement whereas for spherical propagation (above) intensification
occurs intrinsically through convergence - and can be magnified by many orders
of magnitude compared with planar shocks. However, unlike planar propagation,
spherical implosive symmetry necessarily implies "disconnection" from
the forcing device and efficacy is then dictated also by field factors and the
far-field boundaries. An obvious compromise retaining connectedness of plane
shocks and freedom for focussing of spherical shocks is afforded by
cylinridical configuration. Moreover, cylindrical geometry also affords an
opportunity to exploit coherent vortex induction of extreme subpressures by axial straining as well as practical
prospects for continuous operation or rather resonantly cyclic semi-continuous
operation without the introduction of mechanically vulnerable moving surfaces.
This, then, is the principle on offer as a system cycling between two
end-states - one being vortex amplification by acceleration of axial flow, the
other being shock generation by collapse of the vapour filled vortex. Key will
be connecting the two as a resonant device to minimise the driving energy and
this is where the IPR resides and is still available apparently. A benchtop
unit would suffice both for feasibility and as demonstrator for commercial
consolidation. Further information on indication of intent to adopt for
evaluation, basis to be agreed by negotiation.