Next step :
Scaling up to 40 litres displacement.
Design done, but not constructed yet.
Scaling up from 600 cc to 5 liter displacement unit has been demonstrated
and permit to conclude into a straight forward scaling to 40 liter displacement.
Below are some anticipated characteristics of this next machine!
Quasiturbine QT40LSC Pneumatic - 100 kW
(A 40 liters displacement per revolution)
COMPLETE and RUNNING!
Sales for ???? US$ (see purchase order at the bottom of the page)
Air freight available worldwide.
(Custom exempted within North America NAFTA zone).
Quasiturbine has no vane
Unlike vane pumps, which vane extension is important and against which the pressure acts
to generate the rotation,
the Quasiturbine contour seals have an
imperceptible extension and the rotation does not result from pressure against these seals.
The vane geometry does not allow high compression ratio at TDC (top dead center), while Quasiturbine does,
and this is why QT is efficient (less pressure charging losses), and this is why there is no vane combustion engine.
Quasiturbine publishes « efficiency data ».
Quasiturbine Uniflow Characteristic
In most reciprocating piston engines, the flow reverses
its direction at each stroke (counter-flow). By entering and
exhausting the cylinder by the same port, the cylinder valve and walls are
cooled by the passing exhaust, while the hotter incoming admission
is wasting some of its energy in restoring the temperature. Some energy is
further lost in reversing the motion momentum of the mass of gas within
the piston. The aim
of the piston uni(directional)flow is to remedy this defect by providing an exhaust
port at the end of the stroke, making the gas flowing only in one
direction, but has the inconvenience of recompressing some residual
cylinder gas. Quasiturbine is a uniflow engine, with the further
advantage of not recompressing any residual gas, resulting in superior
energy efficiency. Recompressing residual gas means some reversibility
losses, and the pressure increases makes a substantial restriction to the
initial flow into the chamber, not to ignore the truncated cycle
near bottom dead center - None of this with the Quasiturbine.
The QT40LSC Pneumatic research
application unit is a scale up of the
QT5LSC motor where all dimensions have been doubled. Each chamber has a 5
liter maximum volume, and the motor expands 8 chambers per revolution:
Displacement: Total = 8 x 5 liter = 40 liters intake per revolution.
Intake Volumetric Flow Rate = Engine displacement x RPM
Cylindrical outside about 32" (~81 cm) in diameter excluding peripherals.
Thickness 10" (~25 cm) excluding shaft and peripherals.
The casing and rotor are made of metal (no aluminum at this time).
Power shaft: 2 5/8-inch (~6.67 cm) diameter throughout.
2 intake ports 2"
male NPT pipe threads.
2 exhaust ports 4"
male NPT pipe threads.
Weight (all metal) about 1500 pounds (700 Kg).
Simple in-line lubrication.
A silencer may be suitable for some demonstrations.
Not to be used as compressor.
Present typical limitations under proper lubrication:
- Intake pressure: 60 psi (4 bar) peak.
- Revolution: 500 rpm.
- Temperature: Under 150 °C (300 °F)
- Torque (2009 version and later):
Up to 2000 N-m (1600 pound-foot) peak (with no step down gearbox).
- Power 100 kW (130 HP) peak
- Pressure-flow energy conversion : +/- 80 % of theoretical single-stage
(optimum across the range - no off-peak penalty)
Maximum Temperature Control:
Provision for thermal expansion is for now limited
to a air motor rotor temperature of 60 C, and 150 C (300 F)
upon special request. Exceeding limit temperature is
noticeable by a sudden rpm reduction, in which case
one should not insist and let the QT cooled down
before trying again in proper condition.
Hydraulic : This Quasiturbine must not be use
with incompressible fluid (liquid hydraulic mode) - When possible, avoid
excessive internal liquid condensation and do not flowed with lubricant.
Not being mass produced, Quasiturbines are like precious « Ferrari »,
while the «
energy cost » to run less efficient equipments may lead to no overall saving.
Among the new emerging technologies like
hybrids, hydrogen, fuel cell, PV solar, in-wheel motor, power windmill, nuclear thermal...
the Quasiturbine is by far the least expensive innovation to familiarize with!
Youtube Video Channel
QT40LSC theoretical main characteristics can be approximated from 3 parameters:
Instantaneous maximum torque for 2 opposed working chambers is 500 + 500 = 1000
N-m / bar (25 + 25 = 50 pound-foot / psi). The average torque is 65 % of
the instantaneous maximum, which is 670 N-m / bar (32 pound-foot / psi) differential effective
pressure through the motor, assuming no truncated intake);
The RPM revolution within reasonable range and the intake geometric flow (5 liter
x 8 chambers per revolution x rpm, assuming no truncated intake);
The power output which is
proportional to the product: Torque X rpm.
Typical value given as indication only. May vary from one QT to another.
Air (gas) consumption:
For most positive
displacement engine, the Intake
Volumetric Flow Rate is the displacement
time the rpm, which gives for the QT40LSC:
40 litres x 500 rpm = 20 cubic meter per minute.
The « minimum theoretical air consumption » is exceeded by the same ratio as
pressure-flow efficiency, which correspond to substantial saving when
compared for example, to low torque high rpm vanes motors (see details below).
Theoretical Output Power Extrapolation
: Pressure increases both
the rpm and the torque. Since the power is proportional to the product of rpm
X torque, the power output is roughly proportional to the square of the
pressure. Increasing the pressure by 3 fold would then increase the power
by 9 times! (100 kW at 4 bar would theoretically become 900 kW at 12 bar
- or - 130 HP at 60 psi would theoretically become 1200 HP at 200 psi).
This is of course outside the operational
range of the present machines...
Expanders expand the gas of a reservoir, but not necessarily the gas within the expander.
The efficiency is a ratio expressed in %. It is used to evaluate an
equipment result in relation to either the incoming energy (Semi absolute
efficiency - when for example for gasoline engine: energy extraction,
transportation and refining are discarded), either in relation to a partial form of
energy (relative efficiency), or in relation to the result of an other
equipment or reference theory (comparative efficiency). To further
complicate the situation, different engines with same efficiency on bench
test will lead to different efficiency applications (in mobility for example,
due to weight and gearbox
requirement). No correct efficiency interpretation is possible without
knowing detail calculation. Consequently, it is
not possible to optimized simultaneously an expander for maximum power and
maximum efficiency, a choice must be done.
The efficiency is generally in relation to the task an equipment is
attempting to accomplish, and in the present context all « single-stage
expanders » can conveniently be compared to the « single-stage expander
theoretical model (without intake cut-off) », which is simply a piston
making work under pressure, while moving in an infinitely long cylinder
(which is a useful reference):
Theoretical Single Stage (TSS) Calculation:
British units: (See theoretical line on the British units graph)
Power (HP) = Pressure (psi) X Volumetric Flow Rate (VFRcfm) / 229
(As an example: 1 HP = 7.63 VFRcfm at 30 psi)
Metric units: (See theoretical line on the SI units graph)
Power (kW) = Pressure (bar) X Volumetric Flow Rate (VFRm3/min.) X 1.70
(As an example: 1 kW = 0.29 VFRm3/min at 2 bar)
Devices are not all equally efficient when attempting to match this
theoretical piston-cylinder model, but Quasiturbine does it (with no
intake cut-off) at +/- 80 % of the perfect theoretical single-stage (with
potential improvements up to 95 %). To reach such a level of comparative
efficiency, other concepts need to run at nominal power only, or to use intake cut-off techniques. Such
techniques are adaptable to the Quasiturbine as well, for an overall top performance.
Note: There is more intrinsic energy in the compressible incoming flow
(energy accumulating in the infinitely long cylinder as the piston moves)
that single-stage expanders are not attempting to recover (it is not
within their tasks), and which end up in the exhaust. Additional recovery
would require cut-off intake valve and multi-stages (QT?) expanders, but
at a much reduced machine specific power density (larger expander and
Most current compressors are not design for
20 - 60 psi output, which make them running at only a fraction of their nominal
power when feeding a low pressure Quasiturbine. For this reason, compressor must
generally be oversized to sustain experimentation, or the system must have an
important air reservoir. In the case of very high pressure gas tank, not only one
wants to harvest the energy actually in the pressurized air tank, but also take
advantage of the energy amplification possible from using available external
heat. On one side it
is not efficient to make a too important pressure drop into one expander because
the adiabatic cooling will strongly reduce the pushing pressure, and the exhaust
gas will be thrown out at valuable high pressure. On the other side, using a
pinhole regulator will dissipate pressure energy, but will allows the reduced pressure
gas to be thermalized, such as to run the expander with much less adiabatic
cooling and less gas pressure energy thrown at exhaust. Both methods are
compromises. Multi-stages with heat input is hardware intensive, but the best
way to get the most mechanical energy out of a high pressure gas tank with an
external available heat source...
Selecting a high efficiency engine is a good start, but other system
components and thermodynamic cycles also impact the global system
efficiency, which should not be confused with the engine component efficiency.
Comparing Quasiturbine to Vane Motor
Several manufacturers are offering quality products based on Vane Motor concept.
As a matter of preliminary comparison (assuming intake pressure near the
effective internal pressure), here are some typical data of
Quasiturbine versus a GAST air product (calculated
under same running pressure):
Quasiturbine QT.6LSC under 4 bar (59 psi) and 500 rpm: 1.7 kW // 2.3 HP
Intake Volumetric Flow Rate (IVFR) = 0.3 IVFRm3/min // 10.6 IVFRcfm
Effective Displacement: 0.3 IVFRm3/min / 500 rpm = 600 cc // 36.6 po3 per revolution
Consumption: Free air* = 1.5 m3/min of free air // 53 cfm of free air
(* Estimated at 4 bar (59 psi) as 5 times the IVFR of 0.3 m3/min).
Consumption Specific = 0.88 m3/min-kW of free air // 23 cf/min-HP of free air
Theoretical Single Stage Power (TSS) = 4 bar X 0.3 m3/min X 1.70 = 2.04 kW
Theoretical Single Stage Power (TSS) = 59 psi X 10.6 IVFRcfm / 229 = 2.74 HP
QT Performance: 1.7 kW / 2.04 kW = 2.3 HP / 2.74 HP = 83 % of TSS
GAST 4AM Vane motor under 7 bar (103 psi) and 3000 rpm: 1.3 kW // 1.7 HP
Intake Volumetric Flow Rate (IVFR)* = 0.25 IVFRm3/min // 9.2 IVFRcfm
(* Estimated at 7 bar (103 psi) as 8 times less
the flow of 2.0 m3 free air /min).
Effective displacement: 0.25 IVFRm3/min / 3000 rpm = 83 cc // 5.1 po3 per revolution
Consumption: Free air = 2 m3 free air /min // 70 cfm of free air
Consumption Specific = 1.53 m3 free air /min-kW // 41 cf/min-HP of free air
Theoretical Single Stage Power (TSS) = 7 bar X 0.25 X 1.70 = 3.0 kW
Theoretical Single Stage Power (TSS) = 103 psi X 9.2 / 229 = 4.0 HP
GAST Performance: 1.3 kW / 3.0 kW = 1.7 HP / 4.0 HP = 43 % of TSS
From the energy reversibility (heat lost) point of view, the
difference is even greater, as one consumes its air
volume at 7 bar (100 psi), while the QT consumes it at
only 4 bar (60 psi).
In conclusion, the Quasiturbine concept (without intake cut-off)
operates at 80 % of the Theoretical Single Stage
(TSS) Power, compared to 40 % for Vane Motor concept
(even when using some intake cut-off saving), with
QT potential to reaches 95 % under high mechanical
tolerances. Furthermore, QT operates in the most demanding conditions of
high displacement, low pressure and high torque.
Consequently, the Quasiturbine air/steam concept
exceeds substantially the relative efficiency of
Vane Motor concepts, which is consistent with the
vane loading chamber volume lost. For many
applications, there is little or no benefit to use
vane air motor when the pressured fluid
consumption is the dominant cost factor.
Feed Line Capacity
Flow velocity near a piston valve is always impressive, and
it is not different with the Quasiturbine intake ports.
To sustain 500 rpm in a 40 litres displacement QT40LSC, the intake flow rate must
be (40 litres X 500 rpm) = 20 m3 / min..
Knowing that a 2 inch diam. tubing contains 2 litres / meter long, this
correspond to a flow velocity in the tube of :
(20 m3 / min.) / (2 litre / m) = 170 m / s or 600 km / h
Could be half, considering that the Quasiturbine has 2
intakes which could be feed individually. Velocity near the intake ports will be
even higher. Consequently, such a relatively small tubing must be quite short
(or act as a limiting safety factor to protect the unit?). This shows that a
proper feed line design capacity must not be under minded to achieve a good
system integration, with special attention in matching the end of the feed line
with a damper tank for optimum load under fluctuating flow. Notice that once the
pressurized fluid gets into the engine, the flow velocity reduces to match the
tangential rotor speed, which is:
(engine perimeter = 2 m) X 500 rpm = 17 m / s = 60 km / h
and flow speed increases again into the
exhaust, which must show minimum restriction.
Using Air Motor as Compressor
Turning in reverse a Quasiturbine air motor will make it act as a
compressor (not efficiently if not properly design for that role). However,
the direction of rotation can be keep the same, if
both exhausts are plug by a small check valve line taking the exhaust
pressure exit as the compressor output. Then, to prevent the air motor
intake two lines to be vacuumed, a check valve on them allowing-in
atmospheric air will suffice. This kind of switching motor-compressor mode
without changing the direction of rotation is useful for application
like windmill back up pneumatic air storage or vehicle breaking energy
QT40LSC Pneumatic - Purchase Order (PO) Form
(Notice: Product not yet available)
To : Quasiturbine Tronçonneuses
Casier/Code/Porte 2804 - 3535 Papineau
Montréal Québec H2K4J9
514-527-8484 Fax: 514-527-9530
Associated website :
Quasiturbine model QT40LSC Pneumatic (100 kW peak)
(pre-commercial unit) with simplified central differential and shaft,
is intended for integration research, demonstration and projects.
To be use only under competent supervision.
Guaranty is limited to the replacement (pick-up) of defective parts.
Sale done FOB Montréal, Québec Canadaoney rate conversion at
Price including Canadian local sale taxes when applicable
but not the shipping
and custom fees
(NAFTA Exempted?) H.S. # 8413.81:
The associated web page
is an integral part of the present purchase order
and constitute the terms and conditions accepted by the buyer.
Company Name: __________________________
Shipping address: _________________________
Weight: 1000 kg / 2200 pounds;
Size: 1.2 m X 1.2 m X 1 m high / 48 X 48 X 40 inches height
Email the form to
firstname.lastname@example.org or fax to 514-527-8484.
An invoice will follows with payment instructions.
(Terms: 50 % on invoice, the balance 10 days before shipping).
A 12 poles AC generator would be a good RPM
match with Quasiturbine.
For information (not necessarily recommendation),
see also the following:
The PTO Generator considered by APUQ on their website at
A fraction of the engine output is lost in the electric conversion process.
Example: 8 kW for 900 $ at
Also available up to 150 kW in European standard (ex.
(The following are non-tested possibilities...)
Gas Pipeline Pressure Energy Recovery - Rotary Pressure Expander
What about an "energy recovery rotary pressure regulator" ? An
interesting application of the pneumatic Quasiturbine is to recover the
pipeline high pressure energy at local distribution stations. Instead of
using a conventional pressure regulator (an energy dissipative device), a
pneumatic Quasiturbine will rotate under the pressure differential and the
flow will be controlled by the rpm, i.e. the torque applied on the
Quasiturbine shaft. It does act as a dynamic active rotary valve.
This way, the Quasiturbine can transform the pressure
differential into useful mechanical work to run pump, compressor,
ventilator, electricity generator or locally convert the energy in high
grade heat (better than pre-heating the gas before that
same "rotary expander", to avoid any residual condensation as done with conventional regulators).
Substantial heat is now given to conventional expansion valve in pure
lost, while heat given to the gas at the intake of a rotary expander is
essentially all recovered in mechanical energy or electricity. Because conventional turbines can not be widely
modulated in rpm and load, they are not suitable for gas flow and pressure
control, while the Quasiturbine is essentially a closed valve at zero rpm,
and has high efficiency at all torque and all flow rpm. With such a system, any heat added before the
Quasiturbine expands the gas and increases the available volumetric flow
with the result that this heat is converted in mechanical energy with a
very high efficiency. All experimental demonstration has to be done only by gas
experts and under all current rules and regulations. Ignoring gas
expansion and considering only the gas pressure flow, a 36 inches diam.
gas pipeline at 700 psi carry typically a pressure power in excess of 30
MW - 25 millions of pound-ft/sec - of zero pollution pure mechanical
energy almost totally recoverable through Quasiturbines in the heart of
cities and industrial parks. This is tens of giant windmills on kW-h basis!.
A survey (M. Dehli, GWF Gas-Erdgas 137/4, p.196, 1996) showed that in
Germany alone, the potential for utilizing this pressure in 1996 was
200-700 MW, and the gas consumption has increased since then... See the
pipeline technical paper and the
Quasiturbine Rotary Expander.
Enhance efficiency of LNG liquefaction cycle.
Adsorption Refrigeration Engineering Thermal
Physics. Conventional pressure regulators make all the gas to
expand from the constant high pressure side, and the gas pressure-kinetic energy
at the needle is converted into undesirable heat, reducing accordingly the
amount of cold produced. The Quasiturbine rotary expander allow for individual
chamber to expand at a variable reduced pressure during expansion, and such
reduces the gas kinetic energy transformation into destructive heat.
Furthermore, the Quasiturbine recuperates mechanically the gas differential
pressure energy, which can be used to run more compressors and make more cold...
A double energy efficiency gains! A single Quasiturbine in tubo-pump (tubo-compressor)
mode could have one circuit used as rotary expander while the other is used to compress back some of the expanded gas.
This offers great enhancement of thermodynamic
cooling machine, and specially in high power LNG - Liquid Natural Gas
liquefaction stations. Of course, this efficiency enhancement is also available
for more modest cooling system and air conditioning equipments. With
Quasiturbine rotary expander, the efficiency of a gaseous only (like dry
air) system reaches almost the efficiency of a phase change liquid-gaseous
sophisticated phase change chemical products often environmentally unwelcome are
not anymore needed. See Quasiturbine Rotary Expander.
Low Pressure Modulated Power Station
Solar radiation varies greatly during the day while most engine keep their
optimum efficiency at design power only. Because the Quasiturbine (steam
or pneumatic) keeps it high efficiency on a large power range, it is well
suitable for modulated (from source or demand) power production like
solar, windmill, ocean wave station... where the pressure is generally
low, and efficiency critical!
A 10 second vehicle Power Booster. Originally, hybrid was intended
for efficiency increase, not for performance increase. More and more
vehicles use 2 engines not for fuel savings, but to increase acceleration
performance: As a 10 seconds Power Booster, benefiting a government grant!
In this regards, the Quasiturbine QT5LSC pneumatic with an onboard air
tank and compressor could eventually provide hundreds of additional HP for 10 seconds, and make
an unbeatable acceleration Quasiturbine Hybrid vehicle... the market seem
to ask for? Many others applications require high power bursts, like in
smooth landing parachuting (with fast line-winding in less than 10
ORC (Organic Rankine Cycle)
Engine suitable for ORC (Organic Rankine Cycle) in Solar, Geothermal and Waste Heat Recovery.
Condition of Operation
It is the buyer and/or operator responsibility
to comply with all applicable national
and local laws and rules, including those on security and pressurized products.
It is the buyer and/or operator responsibility
to comply with all applicable national and local laws and rules,
including those on security and pressurized products.
Familiarize yourself well beforehand with the Quasiturbine
technology (see the associated site at:
Intended for near ambient temperature intake air (be
careful not to run a supply air compressor for a too long period, which
could overheat the intake air).
For optimum performance, the feed line must be well
balanced between the two intake ports, which must be done by ending the line
passed the 2 T by an accumulator (buffer) tank (minimum 100 litres), on which
the pressure gage can be located.
Always make it turns gradually (without abrupt acceleration).
In break-in phase, reposition the rotor away of a dead spot before each start,
by turning the central shaft.
Always ensure that the rotor is adequately lubricated (pneumatic tool oil
only).(Never use oil with additive like antifriction,
because large air flow or steam oxidized the oil and precipitate the
additives in glue like product fatal to the Quasiturbine operation). The
best is oil injection within one of the intake port using a small pulsed
pump (electrical or pneumatic). A convenient way is to keep the oil
reservoir pressurized slightly over the QT intake pressure, and to simply
control the oil flow through a needle valve.
Simplified differential periodically requires grease
on the central shaft flat section.
Ensure that the hoses and fasteners (particularly the flexible ones) are of
quality and well anchored.
Use a good pressure regulator to limit the maximum pressure and place a
pressure gauge close to the engine intake.
It is recommended not to exceed 500 RPM and/or 4 bars (60 psi) at the
pressure gauge when under load, half without load. No free running at more
than 20 psi, and for short period only.
Avoid flow restriction at exit.
The use of a tachometer (with magnetic pick up, like the one used on bicycle ?)
is cheap and also recommended.
Once in use, the engine will progressively break-in and rotate better and better,
periodically dismantlement may require little break-in every time...
Never exceed the recommended limits.
Intake air must be reasonably clean and near ambient temperature.
Not be used as compressor.
Silencer could be used (not supplied) with some effect on efficiency.
It is the buyer and/or operator responsibility
to comply with all applicable national and local laws and rules,
including those on security and pressurized products.
Must be operated under the
constant supervision of qualified adults.
Anchor the unit well before each start-up.
Never exceed the limits and suggested conditions of operation.
Wearing safety glasses, mask and fastened hair is recommended.
The demonstration room must be well ventilated.
Check the tightening of the bolts and adapters. Be aware of the rupture
or the decoupling of any of the flexible hoses.
Have a distant valve at hand to cut the air/nitrogen flow as needed.
Particularly during breaking-in under compressed air, it can happen that
the rotor stops at a dead point, and refuses to turn when the pressure is
applied. This situation is unstable and call for urgent pressure release. In
absence of pressure, slightly turn the rotor with the central shaft and
pressurize it again...
During the demonstration, nothing should approach the central zone of
make observations at a distance of 50 cm (20 po.) or more.
Always remain vigilant and careful!
Sale and operation are restricted to adults only.
Use for integration research and demonstration.
Pneumatic air-nitrogen only (less than 4 bar - 60 psi),
no steam conversion attempt must be made (could be dangerous).
Additional parts of replacement can be ordered by owners.
The Purchasers understand it is a prototype, and release the
manufacturer from all responsibilities relative with the use.
Sold without detailed specification.
Guarantee of the manufacturer is limited to the replacement
(pick-up) of the defective parts.
The purchasers must have read the present page as part of the purchase
order agreement and invoice, and declare themselves satisfied with it.
Sales done FOB Montréal, Québec Canada.
The present document and conditions must be transferred to the chain of
future owners of the unit.
If there is intellectual propriety risk, the manufacturer can simply
refund and not deliver.
PRICE AND SHIPPING
The price includes the applicable local sale taxes if required, but not
the shipping costs.
The insurances and customs fees are the responsibility of
As possible, shipping will be made in the ? weeks following the
reception of the deposit,
or according to the production capability of the moment (to be notified when ordering).
Failure of the buyer to make final payment or take delivery of the unit
within 3 months of the notice of completion will be interpreted as an
abandon of the product without compensation.
Manufacturer under a privileged QT-Rotors supply license agreement
Casier/Code/Porte 2804, 3535 Papineau, Montréal Québec H2K 4J9 CANADA
(514) 527-8484 Fax (514) 527-8484
Associated website www.quasiturbine.com
Subject to changes without notice - January 7, 2015