Method and apparatus for stabilizing the thickness of an optical channel for extended pressure environments
Inventors
Howard, Paul L. • Tucker, John E. • Reintjes, John F.
Assignees
Publication Number
US-9541492-B2
Publication Date
2017-01-10
Expiration Date
2035-06-01
Interested in licensing this patent?
MTEC can help explore whether this patent might be available for licensing for your application.
Abstract
A high pressure optical flow cell system suitable for use in a real time optical particle monitoring system. The system is modular, with at least two housings joined together with removable mechanical attachment devices. Inlet and outlet passageways introduce and remove high pressure fluid into a flow cavity located between adjacent housing faces. An o-ring or other compliant member seal is provided between the faces to prevent leaks of the high pressure fluid. At least one optical window is provided with a substantially planar face flush with the flow cavity surface. An optical assembly maintains the face of the optical window flush with the flow cavity surface over a wide range of temperatures and pressures. A system and method for maintaining the face of the optical window flush with the flow cavity surface over a wide range of temperatures and pressures.
Core Innovation
The invention is a high pressure optical flow cell system designed for real time optical particle monitoring in high pressure fluid environments. It is modular, comprising at least two housing members joined with removable mechanical attachment devices and a spacer member between their planar surfaces defining a flow cavity through which high pressure fluid flows. Optical windows with substantially planar faces flush with the flow cavity surface are mounted in the housing, allowing optical access to the flowing fluid for particle analysis.
The system maintains the optical window surfaces flush with the flow cavity surface over a wide range of temperatures and pressures by using a compliant gasket positioned between the window and housing, and an externally threaded retaining member that compresses the gasket to create a static seal and precise axial positioning of the window end face. Additional components such as washers and spacers of varying compliance are used to absorb thermal expansion and pressure-induced forces, thus stabilizing the optical channel thickness.
Claims Coverage
The claims cover several inventive features centered on a high pressure optical flow cell system, including its structural components, sealing methods, optical window assembly, and optical flow method.
Modular high pressure flow cell assembly
A flow cell comprising two housing members with a spacer sandwiched between their planar surfaces forming a flow cavity defined by a hole in the spacer, where each housing has a gasket groove larger than the spacer hole and inlet/outlet passages to the flow cavity.
Optical window assembly with sealed mounting
An optical window with a smaller cross-sectional end facing the flow cavity, a larger end with a shoulder, a compliant gasket positioned between the window shoulder and a corresponding shoulder in the mounting hole, and an externally threaded retaining member that compresses the gasket to create a static fluid seal and position the window flush with the flow cavity surface.
Dual optical windows aligned on opposite sides for light transmission
Two optical windows mounted in opposing housings with planar end surfaces flush with the housing surfaces for transmitting and receiving light through the flow cavity for optical monitoring.
Mechanical attachment system for housing assembly
Mechanical attachment elements such as threaded screws or bolts arranged to hold the housing members and spacer tightly together against high pressure fluid, with number and size determined by strength requirements.
Gasket sealing with oval or elongated grooves
Gaskets positioned in grooves on housing faces to form static seals around the flow cavity, where the grooves and gaskets can have oval or elongated shapes for effective sealing.
Optional light directing module with dove prism
A light directing module attached to one housing containing at least one reflector, such as a dove prism, to redirect light passing through the flow cavity back through openings in the housings to enable imaging on the same side of the device as the light source.
Combination of washers and spacers with varying compliance
A flat washer and spacer assembly in the window mounting hole, where the washer is thinner and more compliant than the spacer, and the spacer is more compliant than the threaded retaining member, allowing controlled compression to seal and maintain window position.
Method for illuminating high pressure fluid
A method involving providing the described high pressure cell with the window assembly and spacer, introducing high pressure fluid through the flow cavity, and directing light through the optical window into the fluid for particle monitoring, including use of the mechanical and sealing assemblies described.
The claims collectively cover the design and assembly of a modular, sealed high pressure optical flow cell with stabilized optical windows flush to the flow cavity, sealing gaskets, mechanical fasteners holding the assembly against high pressure, optional light directing modules, and methods for illuminating and optically monitoring high pressure flowing fluid through the optical cavity.
Stated Advantages
Ability to maintain the optical window surface flush with the flow cavity surface over wide temperature and pressure ranges, ensuring stable optical channel thickness for accurate particle monitoring.
Modular design allowing easy disassembly and reassembly for cleaning, adjustment, or replacement of optical components and seals.
Capability to change flow cavity thickness readily by replacing the spacer shim with different thickness.
Resistance to high pressure fluid environments exceeding 100 psi, suitable for harsh or caustic fluid conditions such as hydraulic fluids and lubricants.
Modularity with optional adapters and light directing modules for flexible flow and light path configurations in various spatial constraints.
Documented Applications
Real time optical particle monitoring systems for detecting debris and particles in high pressure hydraulic fluid or lubricating oil systems.
Use in flowing fluid systems where particle size, number, and type analysis is required under high pressure conditions.
Fluid flow sensing applications where optical or fiber optic sensors, such as temperature or pressure sensors, can be positioned at the flow cavity surface.
Interested in licensing this patent?