FreeSpin® In-line Turboexpander

Sapphire Technologies’ FreeSpin® In-line Turboexpander (FIT) is a turboexpander-generator system that uses advanced magnetic technologies to recover the energy lost in pressure reduction processes.

FIT converts the kinetic energy of a fluid into rotational energy, enabling the generation of electricity with no added pollution.

Zero Emissions

Pressure energy recovery uses zero fuel and produces zero emissions. The system is hermetically sealed inside a single housing and does not utilize dynamic seals, which often cause environmental hazards upon failure.

Low Maintenance

FIT runs on active magnetic bearings which eliminate the need for a gearbox and a lubrication system. These bearings offer significant advantages over conventional bearings in terms of operating efficiency, remote monitoring capabilities, power consumption, and reliable performance in harsh environments.

Efficient

The high-speed permanent magnet generator is simply constructed and operates with very little losses. It has variable speed and load capabilities and provides greater power density and a smaller footprint than conventional generator systems.

Embedded AI

FIT’s control system uses artificial intelligence to analyze thousands of sensor inputs per second and safely operate the permanent magnet generator. Output data informs predictive insights that reduce failure risk and support smarter asset management.

Components

Inlet Guide Vanes

The inlet guide vanes, or nozzle, direct gas flow toward the expander wheel at the optimal angle. The nozzle is designed to decrease in cross section, increasing the velocity of the gas as it approaches the expander wheel. The configuration of the nozzle and expander wheel categorize FIT as a radial-inflow, axial-outflow turboexpander-generator.

Expander/Turbine Wheel

High-pressure, high-velocity gas enters through the expander wheel from the inlet guide vanes. As the gas moves through the wheel, it depressurizes and causes the wheel to rotate. These components are typically designed to optimize aero efficiency for the pressure reduction process. Application variables affecting wheel design include inlet/outlet temperature, inlet/outlet pressure, volumetric flow rate, and molecular weight. Pressure reduction processes with large pressure ratios may utilize more than one FIT to sequentially recover energy.

Permanent Magnet Generator

The permanent magnet (PM) synchronous generator has variable speed and load capabilities and can operate at speeds up to 30,000 rotations per minute. The PM generator is directly coupled to the expander wheel: it converts the rotational energy created by the depressurized gas moving through the wheel into electricity. The PM generator consists of a powered stator coil, which creates an electric field, and a magnetic rotor that rotates within that field. The latest technology in rare earth magnets is used to achieve high efficiency and high power density.

Active Magnetic Bearings

Active magnetic bearings (AMBs) allow the rotating components of the turboexpander-generator to operate in a levitated condition, reducing friction and minimizing maintenance as compared to conventional bearings. The AMBs’ control system uses artificial intelligence-enabled diagnostic capabilities to provide operators with insight into system health and performance. Remote monitoring services and predictive maintenance packages are available. Locally, a graphical user interface displays real-time data from the AMBs which can be used to describe changes in pressure reduction process conditions like gas flow, temperature, and density.

Components

Inlet Guide Vanes

The inlet guide vanes direct gas-flow toward the expander wheel at the optimal angle. These are designed much like a water wheel, but the concentric cavity gradually increases in cross section from inlet to outlet allowing for expansion of the gas. Radial turboexpanders are designed with axial flow inlets and radial flow outlets such that the gas is expanded radially through the turbine wheel.

Expander/Turbine Wheel

High pressure gas enters through the expander wheel where the kinetic energy is extracted from the gas stream. The gas leaves the expander wheel at a lower pressure and temperature. The turbine wheels are typically designed to optimize aero efficiency. Application variables affecting turbine wheel design include inlet/outlet temperature, inlet/outlet pressure, volumetric flow rate and fluid characteristics. When the pressure ratio is too large to reduce through a single stage, multi-stage turboexpanders are required.

High-speed Permanent Magnet Generator

The permanent magnet synchronous generator is utilized in a high-speed, direct-drive turboexpander for power generation. The permanent magnet (PM) generator in the FreeSpin® In-line Turboexpander is directly coupled to the turbine shaft and converts the rotational mechanical energy from the turbine into useable electricity via the variable speed drive. The direct-drive, permanent-magnet generator has variable speed and load capabilities and can run at speeds up to 30,000 rpm. The patented technology also offers high-speed operation, simplified controls for power generation and no maintenance.

The PM generator consist of two basic parts. A stator coil powered by an alternating current to create an electric field and a rotor made of special magnetic material that rotates within that field. The high-speed PM generators utilize the latest technology in high-strength rare-earth magnetic materials to achieve high efficiency and a high-power density. In comparison to other generator types, the PM generator has higher efficiency therefore improving the overall system efficiency and has higher power density allowing for a compact size at all power levels.

Active Magnetic Bearings

The magnetic bearings in the FreeSpin® turboexpander are highly reliable, reduce operating costs and expand machine operating parameters. An AMB allows the dynamic components of the FIT to operate in a levitated condition, consuming very little energy and eliminating maintenance as compared to conventional bearings. The AMBs are controlled by magnetic bearing controller, which controls and monitors conditions of the AMB system, allowing complete control of the system and adaptive control under varying load conditions.

The AMBs have built-in diagnostics capabilities that provide users with insight into the generator’s health and performance by monitoring axial and radial load conditions. With a connection to the computer, identifying, analyzing and archiving the health and historical performance of the machine are all possible remotely. This protects the machine and provides process characteristics enabling diagnostics of the gas flow. The graphical user interface (GUI) provides insight into all aspects of magnetic bearing and machine performance and can be utilized to view real-time data, such as changes in mass flow, temperature of internally powered components and density without any additional equipment.

Installation, Commissioning, and Maintenance Services

Sapphire Technologies’ service team supports the field installation and commissioning of FIT.

During commissioning, our technicians and engineers will verify all aspects of FIT installation and prepare the system for start-up. The system will be tuned to factory specifications and the operator will be trained on system operation.

Though there is little maintenance required for FIT, Sapphire Technologies supports field maintenance requests as required. Remote monitoring capabilities allow for maintenance issues to be diagnosed and resolved quickly.