Quasiturbine> Type> Pumps, Turbo-pumps


Pumps are known to be distinct from engines.
To pump, an engine must to be added to drive the pumping device?
Not any more, as the Quasiturbine completely integrates pump and engine concept!

Quasiturbine Pumps / Compressor

Two Circuits

In the pump mode, a Quasiturbine driven by an external motor has 2 intakes and 2 exits related to 2 quasi-distinct circuits. Each circuit can be used as vacuum or pressure pump, for compressible or non-compressible fluids. The Quasiturbine is a positive displacement pump, and does not make use of aero- or hydro-dynamic flow consideration. Possible absence of check valve is of considerable interest in many applications.

Quasiturbine Turbo-Pumps

Because each Quasiturbine has 2 quasi-independent circuits, one can be used in pneumatic, steam or hydraulic motor mode, while the other is used as vacuum or pressure pump. In such a set-up, no external motor is needed to drive the Turbo-pump. There is no need of a central shaft either. Possible absence of check valve is of considerable interest in many applications.


Double reversible circuits and self-priming demonstration


Since the 2 circuits share the moving pivoting blade rotor surface, this mode is mainly suitable to applications where the fluid contamination between the 2 circuits causes no problem, or for uses as vacuum pump. In this mixed mode, the Quasiturbine is at the same time the turbo-engine and the pump and has no shaft in the center, the engine circuit being pressurized at its intake port and the exhaust exit being 90 degrees away. The other pumping cycle intakes by the following port and expels at exit 90 degrees further away.

An optimized turbo-pumps is derived from the standard Quasiturbine engine with minor manufacturing modifications.

Why is it superior?

Less inertia limitation:
Reciprocal pumps reverse the flow while they pump, which is a severe inertia, turbulence and heat generation limitation to high rpm. Because the flow is peripheral and nearly unidirectional, the Quasiturbine is much less sensitive to flow reversal and heat generation, which improves its efficiency.

Check valves:
Check valves are generally preferable only when used with compressible fluid, but the Quasiturbine could as well works without it. Check valve is never required with incompressible fluid like liquid, which is of considerable interest in many applications. The Quasiturbine in motor or pump does not produce vibration.

Compared to other rotary or piston pumps, the flow of the Quasiturbine is relatively more linear in relation to the shaft angle rotation, which makes it a better fuel flow controller...

High flow rate:
When the 2 circuits are used in pump mode, each blade expels its chamber volume when reaching on the top and the bottom, twice per rotation. Since there are 4 blades, the flow is of 8 chambers per rotation, which is more that 60% of the total rotor volume for certain geometry.

Low RPM:
The Quasiturbine is well suitable in the 0 to few thousand RPM range, and consequently the wearing is moderated. The acceleration and flow modulation are also under control.

Efficient at any flow rate:
Contrary to aero- or hydro-dynamic pumps which have an efficiency curve limited to a rather narrow range (outside of which those pumps heat considerably the liquid or the gas), the Quasiturbine pump conserves a high efficiency on a wide range of rotational regime. At zero RPM, this pump could completely cut the flow.

High pressure output:
Because of its robustness and very high geometric compression ratio, the Quasiturbine pump can deliver a quite high pressure output.

Optimization Technology

For all the previous reasons, the Quasiturbine pump and turbo-pump are breakthroughs and open the door to new optimization of present and future devices.

Pistons and Wankels have:
- Dead times where the flow has to stop completely.
- The mass flow direction reverse in piston (not as much in the Wankel).
- They are limited in speed for these reasons.

Turbines have these advantages:
- Continuous flow at intake and exit.
- Single flow direction (no alternate mass direction).
- Higher rotational speed (flow capacity).

But both Piston and Turbine:
- Need two units, one engine to power and one pump.
- Flow is not quite linear with RPM.
- They are leaking fuel circuit at low RPM.
- Top efficiency (power and pump) occurs only at one design speed.

Quasiturbine is somewhat analogue to pump-turbine, because:

- It has quasi-continuous flow at intake and exit.
- Mass flow direction is not alternating but nearly unidirectional.
- Few rotational speed limitation in comparison (for higher specific flow capacity).

Further advantages of the Quasiturbine are:
- At rest, it is a closed pump circuit (turbines leak).
- Flow control is easy, quite proportional to rpm.
- A single rotor can simultaneously be used as a power circuit
  and as a pump circuit, removing shaft coupling and alignment.
- A real turbo pump! (notice the 2 intakes and the 2 exhausts,
  saving weight an volume).
- Several thousand HP pump is feasible in compact high pressure unit.
- Top power and pump efficiency at all RPM.
- Plastic or ceramic units can be without any radar signature! 


From the basic QT75SC 75 cc per chamber engine bloc, a turbo-pump prototype has been built making use of 2 parallel motor and pump circuits of 300cc per revolution each, pumping a total of about 1,5 cubic feet per minute at 100 rpm (non-compressible fluid - zero psi differential).

The Quasiturbine is a very compact and light device, without power shaft, which allows to pump large volume with the flexibility of pneumatic propulsion which self adapt to torque variations without damaging the equipment. Absence of check valve is of considerable interest in many applications. In the underground mines and on explosive construction worksites, it could be used to pump water from compressed air.

The Quasiturbine used in steam turbo-pump mode is well suitable to pump water system condensate directly from steam pressure applied to one of its 2 circuits.

In pump mode, the Quasiturbine gives a nearly linear flow with the rpm on quite a large range, which makes it a precise flow valve or dosimeter for the chemical industries, or eventually as a powerful rocket fuel injector and mixer driven by the combustion gas itself... In application like rocket fuel Quasiturbine turbo-pump, the engine cycle can be pressurized by the combusted gas, while the pump cycle handling fuel, the contaminated engine mode exit being injected into the post-combustion. Notice that the flow rate is controlled by the RPM, but the fuel exit pressure is controlled by the gas pressure at the engine circuit intake, a very interesting characteristic in the case of rockets application.

Refrigeration: 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.

More Technical

Quasiturbine Theory Concept

Quasiturbine Rotary Expander