High temperature optical probe

Abstract

A probe body (12) in an optical probe (10) includes a measurement tube (14) having a plurality of probe vents (16) adapted to allow process fluid to flow therethrough; two or more purge rings, each including a process window, a purge gas inlet, and a plurality of purge gas outlet holes for directing purge gas toward or near the process window; and a measurement region defined by a portion of the measurement tube and the two or more purge rings.

Description

[0001] Claiming priority

[0002] This application claims the benefit of priority to U.S. Provisional Application No. 62 / 786,687, filed December 31, 2018, the contents of which are incorporated herein by reference for all purposes. Technical Field

[0003] In general, the present teachings relate to an apparatus for measuring process gases. More specifically, the present teachings relate to a probe and components thereof for monitoring gases in a high temperature environment. Background Art

[0004] Controlling the environment in which products are manufactured is a key element of good manufacturing practices. Environmental monitoring is also critical for safety. Gas monitoring of processes is often required to help prevent explosions or to protect workers from injury or exposure to toxic gases. Gas monitoring can also be used for process control.

[0005] For example, oxygen analyzers provide valuable measurements in combustion control, process quality, safety, and environmental applications. They are used in a variety of measurement scenarios, including but not limited to power plants, refineries and petrochemical applications, process safety, and product quality in chemical production.

[0006] Different types of sensors can be used to measure the level of oxygen (or other components) in a gas or gas mixture. Exemplary sensors include zirconium oxide oxygen analyzers, paramagnetic oxygen analyzers, and tunable diode laser (TDL) analyzers. However, current sensors or analyzers have disadvantages. Some devices require a transmitter to be installed at one end of a pipe or chimney where the process gas is measured, and a receiver to be installed at the other end. The need for multiple components may complicate installation and maintenance. Current equipment may be compatible only at temperatures lower than desired. For example, some sensors can operate at temperatures up to about 600°C, but for processes above these temperatures, additional steps are required. Additional steps may also require a large amount of equipment. Auxiliary cooling may be required, requiring a cooling jacket and / or a coolant. These additional steps and equipment significantly increase the cost, energy, and complexity of the process.

[0007] Despite efforts to improve the monitoring and analysis of process gases, there remains a need to obtain relevant, information-rich process data. There remains a need for components or devices that are field repairable and / or replaceable. There is also a need for assemblies with replaceable and easily replaceable components so that the entire analyzer does not have to be replaced, or the entire process does not have to be shut down for an extended period of time (if it occurs) to maintain the analyzer and its components. There remains a need for assemblies that can operate at low and high temperatures and assemblies that can withstand temperature fluctuations. Low mains power consumption is also required when measuring and analyzing process gases, especially in high temperature applications. There remains a need to monitor process composition using low-cost, reliable in-situ measurement devices that do not require sample conditioning and can withstand harsh, high temperature and high pressure conditions. Summary of the invention

[0008] The present teachings utilize a simple and elegant construction method by which relatively few components may be used to accomplish the detection of process fluids to determine the composition of a process fluid or to monitor specific elements within a process fluid.

[0009] The present teachings include a probe body. The probe body may include a measuring tube having a plurality of probe vents adapted to allow a process fluid to be analyzed to flow therethrough. The probe body may include one or more purge rings. The purge ring may include a process window, a purge gas inlet, and a plurality of purge gas outlet holes adapted to direct the purge gas toward or near the process window. The probe body may include a measuring region defined by a portion of the measuring tube and two or more purge rings. The probe body may be capable of withstanding temperatures up to and including approximately 1100° C. The probe body may be adapted for use with a single-ended optical probe. The probe body may be adapted to be removably fixed to a transmitter of the optical probe.

[0010] The measuring tube of the probe body can have probe vents aligned in longitudinal and radial rows and columns. The probe vents can be in a generally symmetrical configuration (e.g., if a longitudinal plane bisects the measuring tube). The measuring tube can be formed of a material that resists sagging when exposed to high temperatures (e.g., up to and including about 1100° C.). The measuring tube can be formed of a material having a melting point of about 1150° C. or higher. The measuring tube can be formed of a material that resists oxidation to about 1100° C. or higher (e.g., about 1150° C.). The measuring tube can be formed of a nickel-based alloy, such as RA330.

[0011] The probe body may include one or more purge gas delivery assemblies. The purge gas may be directed through a purge gas outlet hole. The purge gas outlet hole may be angled so that the purge gas is adapted to rotate around a surface of the process window.

[0012] The probe body may also include a retroreflector assembly located at the end of the probe body. The retroreflector assembly may include a retroreflector having two or more reflector walls, which are suitable for redirecting light emitted from a light source such as a laser or an LED. The retroreflector may be formed of a material capable of withstanding temperatures up to and including about 1100°C. The retroreflector may be formed of a material different from the material forming the measuring tube. The retroreflector may be formed of a material having a melting point of about 2000°C or higher. The retroreflector may have a different thermal expansion coefficient from the measuring tube. The retroreflector may be formed of an aluminum oxide material. For example, the retroreflector may be formed of sapphire. The retroreflector assembly may include a riveted seal for holding the retroreflector in place. The riveted seal and the retroreflector may each include a bonding feature for fixing the retroreflector in the riveted seal. For example, the bonding feature may include complementary shape features, such as concave and outer rounded corner shapes.

[0013] The present teaching also contemplates an optical probe comprising a probe body and a transmitter as described herein. The transmitter may be equipped with one or more light sources and electronic components. The optical probe or probe body may be used to measure and / or analyze process fluids. For example, the probe may be used to assess the composition of a fluid or determine the amount of a specific compound in a composition.

[0014] The present teachings also include a method comprising directing light in a first direction through a process window of a probe body, into a measurement region and through a process fluid flow to a retroreflector; reflecting the light in an opposite direction via the retroreflector in a direction substantially parallel to the first direction; and analyzing the composition of the process fluid. The method may further include pumping a purge gas to one or more purge rings and directing the purge gas toward or near the process window via a plurality of purge gas outlet holes to clean the process window. The purge gas may flow through the probe body at about 2 L / min or less.

[0015] Thus, the present teachings provide a probe body that can be isolated from the transmitter, which allows replacement of the probe body. The probe body allows the ability to mount optical elements to measure or determine desired characteristics or components of a composition. The probe body can withstand high temperatures without significant sag or loss of mechanical integrity and / or can withstand a wide range of temperature changes. The present teachings provide a low-cost method for probing process fluids. The data obtained is information-rich. The true operating conditions can be identified and allow control targets and constraints. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 An exemplary optical probe according to the present teachings is illustrated.

[0017] Figure 2 An optical configuration of an optical probe according to the present teachings is illustrated.

[0018] Figure 3A An exemplary measuring tube of an optical probe according to the present teachings is illustrated.

[0019] Figure 3B An exemplary purge assembly according to the present teachings is shown.

[0020] Figure 4 An exemplary purge ring assembly according to the present teachings is shown.

[0021] Figure 5 An exploded view of an exemplary purge ring assembly according to the present teachings is shown.

[0022] Fig. 6A An exemplary retroreflector assembly according to the present teachings is shown.

[0023] Figure 6B Shows Fig. 6A An enlarged view of a portion of a retroreflector assembly.

[0024] Figure 7 An exploded view of a retroreflector assembly and purge ring in accordance with the present teachings is shown. DETAILED DESCRIPTION

[0025] As required, detailed embodiments of the present teachings are disclosed herein; however, it should be understood that the disclosed embodiments are merely examples of the teachings that may be embodied in various forms and alternative forms. Figures are not necessarily to scale; certain features may be exaggerated or minimized to show details of particular components. Therefore, the specific structural and functional details disclosed herein should not be interpreted as limiting, but merely as a representative basis for teaching those skilled in the art to use the present teachings in different ways.

[0026] In general, and as will be understood from the following description, the present teachings relate to probe bodies for optical probes, optical probes, the use of probe bodies and / or optical probes, and methods of detecting process fluids to determine specific levels of components that make up or monitor a composition. For example, the probe can be used to monitor the oxygen level of a process fluid. Where the present application relates to fluids, it is contemplated that these fluids include gases.

[0027] The present teachings relate to optical probes and components thereof for measuring and / or analyzing the composition of process fluids. Optical probes can be used to measure the composition or conditions within combustion assets, such as large combustion equipment (e.g., furnaces, boilers, thermal processing units, flares, process heaters, etc.). Optical probes may find particular use in furnaces, such as for monitoring combustion gases in olefin furnaces. The present teachings may be used for technologies that do not require HVAC shields. The present teachings may be used for technologies that do not require sample delivery or require a reliable, simpler sample system. As another example, the present teachings may be used for reactor monitoring or distillation column monitoring.

[0028] Compared with other methods, other probes or parts thereof for measuring or analyzing process fluids, this teaching can provide cost savings. This teaching can provide reliable equipment and methods for measuring or analyzing fluids. The probe or its parts can allow direct detection of the chemical characteristics of the compound of interest. The probe or its parts can provide information-rich data. The probe or its parts can identify the real operating conditions. The probe or its parts can allow the current target or constraint to be controlled based on the collected data. The probe or its parts can withstand high temperatures (e.g., up to and including about 1100°C). The probe or its parts can be able to withstand a wide range of temperature changes, thereby maintaining mechanical integrity, avoiding optical element breakage, or both. The temperature change can last for a very short period of time (e.g., a few minutes, a few hours).

[0029] Typically, the optical probe according to this teaching may include a transmitter and a probe body. The probe body may include one or more purge rings to ensure that the optical window in the probe remains clean, transparent and / or free of condensation or debris. The probe body may include a retroreflector for guiding light through the probe to achieve measurement or monitoring of process fluids. The optical probe may be a single-ended optical probe. Therefore, the probe body may be inserted into a chamber or device component for measuring a desired condition (e.g., monitoring a specific compound or analyzing a process fluid's chemical signature). Therefore, the probe may be in a cantilever direction. For example, the probe body may extend into a chamber or device component and may be held in place or fixed to the structure by the structure defining the chamber.

[0030] The optical probe may include a transmitter portion. The transmitter may include one or more light sources of the optical probe. The transmitter may include electronic components of the optical probe. The transmitter may include one or more light sources, such as one or more laser diodes or light emitting diodes, one or more beam splitters, one or more photodiodes, or a combination thereof. The transmitter may include a main housing for accommodating components of the transmitter. The transmitter may include an optics housing for accommodating optical components of the probe. The transmitter may include a plurality of ports. The ports may include any combination of a verification gas port, an optics purge port, a cable port, and the like.

[0031] The transmitter may include one or more displays or screens (e.g., LCD displays, LED displays, touch pads, etc.) for displaying process conditions, such as temperature, pressure and flow rate, the composition of the fluid stream being analyzed, etc. The transmitter may include one or more features for adjusting the transmitter or components therein. For example, a feature (e.g., a beam alignment adjustment screw) may be employed to ensure that light emitted from the light source is properly directed to achieve an accurate reading.

[0032] The optical probe may include a probe body. The probe body may have at least a portion adapted to receive a process gas. The probe body may be adapted to allow a process fluid to flow therethrough. The probe body may have a measurement region through which the process fluid flows. The process fluid may flow at an angle to a longitudinal axis of the probe body. The process fluid may flow in a direction that is generally non-parallel to the longitudinal axis of the probe body. The process fluid may flow in a direction that is generally perpendicular to the longitudinal axis of the probe body.

[0033] The probe body may be fixed to the transmitter. The probe body may be detachable from the transmitter. The probe body may be isolated from the transmitter. This may allow the probe body to be replaced without replacing the transmitter. This may allow the probe to be customized depending on the application, the size of the probe required, the composition being evaluated, the temperature to which the body will be exposed, etc. The probe body may be retrofitted onto an existing transmitter.

[0034] The probe body may be capable of withstanding high temperatures. The probe body may be capable of withstanding temperatures of about 400°C or more, about 600°C or more, about 800°C or more, or about 1000°C or more. The probe body may be capable of withstanding temperatures of about 1100°C or less. The probe body or its components may be made of any material capable of withstanding the temperatures to which it is exposed. The probe body or its components may be capable of withstanding temperature fluctuations. The probe body or its components may be capable of withstanding temperature changes from ambient temperature up to and including about 1100°C.

[0035] The probe body may include a measuring tube, one or more purge rings, one or more purge gas assemblies, one or more retroreflector assemblies, or a combination thereof. The probe body may allow for the installation of optical elements, such as windows and mirrors, so that data can be collected. The components of the probe body may allow process fluids to pass through the measuring tube in a defined area. The defined area may be defined by one or more process windows, which are suitable for keeping clean, clear, free of or with reduced amounts of debris, free of or with reduced amounts of condensation, or a combination thereof, by a purge assembly, which includes one or more purge rings.

[0036] The measuring tube of the probe body may be a generally hollow structure or may have one or more generally hollow portions. The measuring tube may be generally cylindrical. The measuring tube may have a generally circular or elliptical cross-section. The cross-section of the measuring tube may have one or more generally straight sections. The cross-section of the measuring tube may have one or more generally curved sections. The measuring tube may have a generally uniform diameter (e.g., outer diameter) along at least a portion of its length. The measuring tube may have a varying diameter (e.g., outer diameter) along its length.

[0037] The measuring tube may serve to surround and / or protect other elements of the probe assembly. The measuring tube may enclose one or more lines for conveying purge gas. The inner diameter of the measuring tube may be greater than the outer diameter of one or more other components of the assembly. For example, the outer diameter of one or more purge rings may be smaller than the inner diameter of the measuring tube, so that the purge rings may be fixed, for example, in the measuring tube. The measuring tube may be closed with a cover. The cover may be used to define the purge area of ​​the probe body. The cover may be used to fix and / or protect other features in the measuring tube, such as a retroreflector assembly.

[0038] The measuring tube may be formed of a material that can withstand being placed in a high temperature process. The measuring tube may be able to withstand these temperatures and / or temperature fluctuations without noticeable sagging or overhang. The measuring tube may be formed of a material that is resistant to sagging when exposed to temperatures up to and including about 1100°C. The measuring tube may be formed of a material having a melting point of about 1100°C or higher, or about 1150°C or higher. The measuring tube may be resistant to oxidation at temperatures up to and including about 1150°C. The measuring tube may be formed of a metallic material. The measuring tube may be formed of a high temperature alloy. For example, the measuring tube may be formed of a nickel-based alloy (e.g., RA330) or a cobalt-based alloy.

[0039] The measuring tube may include a measuring region. The measuring region may be adapted to receive a process fluid to be measured or analyzed. The measuring region may be defined by one or more purge rings and the measuring tube.

[0040] The measuring tube (e.g., at the measuring area) may include a plurality of probe vents or openings for allowing process fluid to flow into and out of the measuring tube. The positioning, quantity, and orientation of the vents may be selected to reduce or avoid sagging and / or stress that may occur at elevated temperatures. The probe vents may generally have the same size and / or shape. The probe vents may have different sizes and / or shapes. The probe vents may have a generally elongated shape (e.g., rectangular, stadium-shaped, or oval). The generally elongated shape may extend along the length of the measuring tube (e.g., in the longitudinal direction). A series of vents may generally be aligned along the length of the measuring tube (e.g., forming a row of vents). A series of vents may be radially aligned approximately around the diameter of the measuring tube (e.g., forming a column of vents). The probe vents may be arranged approximately continuously along the length of the measuring tube. The probe vents may be arranged approximately continuously around the measuring tube. The probe vents may be a generally symmetrical configuration (e.g., if a longitudinal plane divides the measuring tube into two). The probe vents may be located generally opposite each other (eg, one or more probe vents are adapted to receive a flow of process fluid and one or more probe vents are located on opposing portions of the measurement tube to allow process fluid to exit the measurement region).

[0041] The probe body may contain one or more optical elements. Optical elements may be used to define the measurement area. Optical elements may separate the process gas from other elements of the probe. Optical elements may be a material that allows light to be transmitted through the probe.

[0042] The optical element may include one or more process windows. The process window may extend generally transversely to the longitudinal axis of the probe body. The process window may be located within the probe body and may extend through at least a portion of the inner diameter of the measuring tube.

[0043] Optical elements, such as one or more process windows, can be made of materials that can withstand high temperatures. The material can withstand temperatures of about 600°C or more, about 800°C or more, or about 1000°C or more. For example, the material can withstand temperatures up to and including about 1100°C. The material can have a very wide light transmission band. The material can be a material that is highly transparent to light of about 150nm or more wavelengths. The material can be a material that is highly transparent to light of about 5500nm or less wavelengths. For example, the material can have a light transmission band from ultraviolet to near infrared. The material can be scratch-resistant. The material can be wear-resistant. On the Mohs scale of mineral hardness, the material can have a mineral hardness of about 6 or more, about 8 or more, or about 9 or more. The material can be much stronger than other optical materials or standard glass windows. The material can include one or more anti-reflective features, layers or coatings. Exemplary materials for optical elements such as one or more process windows may include germanium, silicon, BK7, UV fused silica, zinc selenide, zinc sulfide, sapphire, calcium fluoride, magnesium fluoride, barium fluoride, sodium chloride, potassium bromide, and the like.

[0044] The probe body or probe as described herein may have two or more process windows. A process window may be used to separate the components of the transmitter from the process fluid flowing through the measurement area of ​​the measuring tube. A process window may be located at or near the free end of the probe body. The process window may be used to separate the retroreflector assembly from the process fluid flowing through the measurement area of ​​the measuring tube. One or more process windows may be associated with, surrounded by or part of one or more purge rings.

[0045] One or more purge regions may be present within the optical probe. The purge region may include one or more features for generating a purge gas curtain in front of one or more optical elements (e.g., one or more process windows). The purge gas may be used to isolate the optical elements from the process fluid. The purge region and associated purge assemblies may be used to purge optical elements exposed to the process fluid to avoid, reduce, or remove the accumulation of condensate or particles that may compromise the transmission of light through the probe. The purge region and associated purge assemblies may be used to avoid the possibility of an explosive air / gas mixture existing or forming within the probe. The purge region and associated purge assemblies may avoid unstable mixing with the process fluid. Such unstable mixing with the process fluid may result in increased variability in the effective path length of the process fluid, which may result in higher errors in the analyzer readings. Therefore, purging may provide more accurate readings.

[0046] The probe body may include one or more purge gas assemblies. The purge gas assembly may include one or more tubes, channels or conduits (generally referred to herein as tubes) for directing purge gas from a gas source to a portion or region of the probe body. The tube or conduit may extend in a direction generally parallel to the longitudinal axis of the probe body. The purge gas assembly may be located in any area that does not interfere with the transmission of light or laser beams within the probe. One or more tubes may be arranged at or near the inner diameter of the measuring tube. Multiple tubes may be used. The number of tubes may correspond to the number of openings or inlets of the purge ring.

[0047] The purge gas assembly can be used to deliver purge gas within the probe body. The purge gas can be any gas capable of purging optical elements exposed to the process fluid to avoid, reduce or remove the accumulation of condensate or particles that may endanger the transmission of light through the probe. The purge gas can be any gas at a temperature that does not produce condensation on the surface of the process window. The purge gas can be any gas capable of avoiding the possibility of an explosive air / gas mixture existing or forming within the probe. For example, nitrogen or factory air can be used. The flow rate of the purge gas in the purge gas assembly can be controlled to save resources or reduce operating costs. The purge gas can flow at about 5 L / min or less, about 3.5 L / min or less, or about 2 L / min or less.

[0048] The probe body may include one or more purge rings. The purge rings may be used to direct purge gas to the purge area. The purge rings may have an outer shape that generally matches the cross-sectional shape of the measuring tube. The purge rings may be generally annular. The purge rings may have a generally circular outer diameter. The purge rings may have openings therein. The openings may be located at or near the center of the purge rings. The openings may allow light emitted from a light source (e.g., a laser, an LED, etc.) to be directed through the probe body.

[0049] The purge ring may have an outer diameter that is smaller than the inner diameter of the measuring tube. The purge ring may be sized and shaped to fit within the measuring tube. The purge ring may be positioned at an angle relative to the longitudinal axis of the measuring tube. For example, the purge ring may be positioned or fixed in a direction that is generally transverse to the longitudinal axis of the measuring tube. For example, the purge ring may extend across the width of the measuring tube.

[0050] The purge ring may be generally hollow or may have one or more channels or cavities for receiving, directing and / or containing purge gas. The channels or cavities may be defined by one or more components. For example, the purge ring may include two components. The purge ring may include a first ring or outer ring. The purge ring may include a second ring or inner ring.

[0051] The first ring may have a substantially flat front surface. The front surface may be an annular front surface. One or more outer walls may extend from the outer edge of the annular front surface. The outer wall may extend around the periphery of the annular front surface at an angle to the front surface. For example, the outer wall may extend in a substantially orthogonal direction relative to the front surface. The annular front surface may have one or more openings for receiving a purge gas (e.g., via one or more tubes).

[0052] The second ring may have a substantially flat front surface. The front surface may be an annular front surface. One or more inner walls may extend from an inner edge of the annular front surface (e.g., an edge defining an opening of the ring). The inner wall may extend around the inner edge of the annular front surface at an angle to the front surface. For example, the inner wall may extend in a substantially orthogonal direction relative to the front surface. The annular front surface may have one or more openings for receiving a purge gas (e.g., via one or more tubes).

[0053] In the assembled position, the annular front surfaces of the first ring and the second ring may extend in planes that are substantially parallel to each other. The annular front surfaces of the first ring and the second ring may have substantially the same shape and size. The openings of the annular front surfaces for receiving the purge gas may be substantially aligned. The outer wall of the first ring may extend toward the second ring. The inner wall of the second ring may extend toward the first ring. When the first ring and the second ring are engaged, a cavity for accommodating the purge gas may be formed, the cavity being defined by the inner wall, the outer wall and the two annular front surfaces.

[0054] The purge ring may be located adjacent to or may include a process window. The process window may be received within an inner opening defining an annular shape. The process window may be accessible through the inner opening defining an annular shape.

[0055] The purge ring may include one or more features for directing a purge gas on or near a process window. The purge ring may include one or more purge gas inlets. The purge gas inlet may receive a portion of a purge gas assembly (e.g., a tube). The purge ring may be substantially hollow to accommodate a purge gas.

[0056] The purge ring may include one or more purge gas outlets. The purge ring may include multiple purge gas outlets. The purge gas outlet may be positioned on the inner wall defining the annulus. The purge gas outlet may be an inclined or angled opening. The outlet may be angled toward the process window. The outlet may be inclined inwardly (e.g., toward the center of the process window). The location of the purge gas outlet may be such that a spiral flow or eddy flow is generated on the process window. The purge gas may flow out of the purge ring without diluting the process sample and without affecting the path length of the light source or the laser or both.

[0057] The probe body may include a retroreflector assembly. The retroreflector assembly may be positioned toward the free end of the probe body (e.g., at the end of the probe body opposite the transmitter). The retroreflector assembly may be used to reflect or redirect a light or laser beam (e.g., back to the direction of its origin).

[0058] The retroreflector assembly may include a retroreflector. The retroreflector may include one or more reflective surfaces. The retroreflector may include one or more reflector walls forming a tip. The retroreflector may have a generally conical tip. The retroreflector may have two or more walls connected together to form a point. The retroreflector may be a cube corner retroreflector. One or more walls may be generally flat. One or more walls may be generally curved. The walls may be oriented so that the laser beam or light can be reflected or redirected to a desired location.

[0059] The retroreflector may be formed of a material capable of withstanding high temperatures. For example, the retroreflector may be capable of withstanding temperatures of about 600°C or more, about 800°C or more, about 1000°C or more. For example, the retroreflector may be capable of withstanding temperatures of about 1100°C or less. The material may have a melting point of about 1150°C or more, about 1500°C or more, or about 2000°C or more. The retroreflector material may have a thermal expansion coefficient of about (5.0–6.6)×10-6 / K. The material may be non-flammable. The material may be an aluminum oxide material. For example, the retroreflector may be formed of sapphire. The retroreflector may be formed of a material different from that of the measuring tube. The retroreflector may be formed, at least in part, of the same material as the measuring tube. The retroreflector may be formed of a material having a thermal expansion coefficient different from that of the measuring tube. Therefore, care must be taken to ensure that the mismatch does not result in significant mechanical stresses that may compromise the probe (e.g., due to cracking of the retroreflector or misalignment of the retroreflector).

[0060] The retroreflector may include a main body portion from which one or more walls extend. The main body portion may have a shape that can be received in a fixed portion of the retroreflector assembly, such as a riveted seal. For example, the main body portion may be generally cylindrical. The main body portion may be generally hollow or a material that does not prevent or inhibit light or a laser beam from reaching one or more reflector walls.

[0061] The retroreflector assembly may include one or more riveted seals. The riveted seals may serve to hold the retroreflector in place. The riveted seals may be formed of a material different from the retroreflector. The riveted seals may accommodate mismatches in the coefficients of thermal expansion of the retroreflector material and the mounting material. The riveted seals may allow for stable mounting of the retroreflector when the expansion and / or contraction of the mounting material varies as a function of temperature. The riveted seals may secure the retroreflector within the probe body. The riveted seals may have an external shape that may be accommodated within a measuring tube of the probe body. The riveted seals may have an inner opening adapted to receive a portion of the retroreflector (e.g., a body portion). The inner opening of the riveted seal may be substantially complementary to the shape of the body portion accommodated therein. The riveted seals may be formed of one or more components. The riveted seals may be formed of two or more components. Multiple components may be fixed together (e.g., by laser welding).

[0062] The main body of the retroreflector may have one or more features for fixing the retroreflector in the retroreflector assembly and / or in the probe body. The rivet seal may have one or more features for fixing the retroreflector in the retroreflector assembly and / or in the probe body. The main body and the rivet seal may have substantially complementary features for fixing the components together. One component may include a protrusion, and the other component may include a cavity for receiving the protrusion. The protrusion may be substantially bullnose shaped. The cavity may be a groove or a recess. As an example, the rivet seal may have a bullnose protrusion extending around at least a portion of the internal opening, where the main body of the retroreflector will be received. The main body of the retroreflector may have a recess or a groove extending around at least a portion of the main body. The fixing features may have sufficient tolerance to allow for thermal expansion of different materials.

[0063] As described herein, the retroreflector assembly may include or may be located near one or more purge rings and / or process windows. The purge rings and / or process windows may be used to separate the retroreflector from the process gas without obstructing the path of the laser or light into and out of the retroreflector.

[0064] The optical probe or its components can be used to measure or analyze the composition of the process fluid or analyze certain characteristics, compounds or quantities of the process fluid. The transmitter can contain the optical element of the probe. The probe can include a light emitting device. The light emitting device can emit light with a wavelength of about 10nm or greater, about 240nm or greater, or about 360nm or greater. The light emitting device can emit light with a wavelength of about 1000nm or less, about 975nm or less, or about 950nm or less. For example, one or more laser diodes can be used to emit a laser beam. Another example includes a light emitting diode. The probe can include a beam splitter that can separate light in two or more directions. The light can extend through the body of the probe. A portion of the separated light can be redirected to a reference unit. For example, the reference unit can be used for laser frequency stabilization. The light can be transmitted to one or more reflector walls of the retroreflector. The reflector wall can be used to change the direction of the laser beam. The light can be redirected from one reflector wall to another reflector wall and can be redirected back to the transmitter. Thus, light can be transmitted from the light emitting device in one direction. The light can then be redirected to a substantially opposite direction. For example, one or more reflector walls may direct light in an opposite direction that is substantially parallel to the first direction of the light beam.

[0065] Generally speaking, an optical probe as described herein is capable of converting a light or laser beam into an electrical signal. The physical quantity of light is measured and converted into an instrument readable form. When measuring light as it passes through a process fluid, the components of the process fluid or the level of a specific component can be determined.

[0066] Turning now to the accompanying drawings, Figure 1 An exemplary optical probe 10 is illustrated. The probe 10 includes a probe body 12 and an emitter 34. The probe body 12 includes a measuring tube 14 through which the process fluid to be analyzed enters and exits via a probe vent 16. At the tip of the optical probe 10 is a retroreflector assembly 20 that reflects light from the emitter 34 back to the emitter. Since a purge gas can be used to ensure that the components of the assembly remain clean, a purge port 18 is located on the optical probe 10 where the purge gas enters or exits. The emitter 34 includes a main housing 36 and an optics housing 38. These housings house the electronics and light source of the probe.

[0067] Figure 2The optical configuration of the optical probe is illustrated. A light source 40 projects light 42 into the body of the probe. The light is directed to a beam splitter 44, where a portion of the beam continues through a process window 46 and a portion of the beam is directed to a reference cell 48. The beam that continues through process window 46 extends through a purged region 50 into a measurement region 52 and then into another purged region 50. When the light 42 reaches the retroreflector assembly 20 at the end of the probe, the beam is redirected through reflector wall 24 and reflector wall 24' to the opposite end of the probe to a photodiode 54.

[0068] Figure 3A and 3B An exemplary probe body 12 is shown, including a measuring tube 14 ( Figure 3A ) and components located in the measuring tube ( Figure 3B ).like Figure 3A As shown, the measuring tube 14 includes a measuring area 15 having a plurality of probe vents 16 for the entry and exit of the process fluid. For the purpose of this figure, the process fluid flows into the page through the probe vents 16. As shown, the probe vents 16 are symmetrical to avoid sagging and stress that may occur at elevated temperatures. The size of the vents may depend on the gas to be analyzed, the equipment in which the probe is located, the size of the probe, the temperature to which the probe will be exposed, etc. The measuring tube 14 has a generally hollow body that allows the process fluid to flow therethrough.

[0069] The measuring tube 14 also accommodates Figure 3B The purge assembly 60 includes a purge gas delivery assembly 62 that allows the purge gas to travel within a channel within the measuring tube to the area to be cleaned by the purge gas. The purge gas exits the channel at one or more purge rings 70, where the purge gas is used to purge the optical elements of the probe exposed to the process fluid to avoid accumulation of condensation, particulates, etc., which may compromise the transmission of light through the probe. A purge cap 64 is located at the end of the probe to close the end of the measuring tube 14 and protect the retroreflector assembly 20 and the purge ring 70.

[0070] Figure 4 An exemplary purge ring 70 is illustrated. A process window 72 is located within the ring, and light 42, such as a laser beam or other light emitted from a light source, travels therethrough. The purge ring 70 includes one or more purge gas inlets 78 through which purge gas is permitted to travel. The purge gas exits the ring at a plurality of purge gas outlets 80. The purge gas exits the purge gas outlets 80 in a generally spiral or swirling manner to purge the process window 72 to keep it clear so that the light 42 emitted from the light source can travel therethrough.

[0071] Figure 5An exploded view of an exemplary purge ring 70 is shown. Purge ring 70 includes two components, an outer ring 74 and an inner ring 76. The outer ring 74 and the inner ring 76 each include one or more purge gas inlets 78 for directing process fluid to a purge gas outlet 80 located at the inner ring 76. The inner ring 76 has a portion that extends and fits within the outer wall defining the outer ring 74. When assembled, a chamber is formed between the inner ring 76 and the outer ring 74 for containing and directing purge gas through the purge gas outlet 80.

[0072] Fig. 6A and 6B An exemplary retroreflector assembly 20 is illustrated. The assembly includes a retroreflector 22, shown as a cube corner retroreflector, having two or more reflector walls 24 forming a tip. The reflector walls serve to reflect and redirect light within the probe so that the light is directed back toward the photodiode 54 (see FIG. Figure 2 ). Retroreflector 22 is secured within rivet seal 28, each having features (e.g., complementary features) that allow the components to be connected together. As an example, retroreflector 22 includes a recess 26 or channel adapted to receive a protrusion or outer corner portion 30 of rivet seal 28.

[0073] Figure 7 An exploded view of the retroreflector assembly 20 and the purge ring 70 is shown. The retroreflector 22 is adapted to be located within the opening of the rivet seal 28. The recess 26 of the retroreflector 22 receives the outer corner portion 30 of the rivet seal to secure the retroreflector within the assembly. The rivet seal 28 includes a plurality of purge gas inlets 32 that align with the purge gas inlets 78 of the purge ring 70, thereby allowing the purge gas to pass through the assembly and exit through the purge gas outlet 80. The purge ring 70 and the purge gas keep the optical elements free of debris, condensation, etc. so that light can properly reach the retroreflector and be reflected therefrom.

[0074] Although exemplary embodiments are described above, these embodiments are not intended to describe all possible forms of the present invention. On the contrary, the words used in the specification are descriptive rather than restrictive, and it is understood that various changes can be made without departing from the spirit and scope of the present invention. In addition, the features of various execution embodiments can be combined to form further embodiments of the present invention.

[0075] Any numerical value listed here includes all values ​​from lower value to higher value in increments of one unit, provided that there is an interval of at least 2 units between any lower value and any higher value. For example, if the value of the amount of the specified component or process variables such as temperature, pressure, time, etc. is, for example, 1 to 90, preferably 20 to 80, more preferably 30 to 70, it is intended to clearly list values ​​such as 15 to 85, 22 to 68, 43 to 51, 30 to 32, etc. in this specification. For values ​​less than 1, one unit is considered to be 0.0001, 0.001, 0.01 or 0.1 as appropriate. These are just examples of specific intent, and all possible numerical combinations cited between the minimum and maximum values ​​are considered to be clearly described in a similar manner in this application.

[0076] Unless otherwise indicated, all ranges include the endpoints and all numbers between the endpoints. The use of "about" or "approximately" in connection with a range applies to both ends of the range. Thus, "about 20 to 30" is intended to cover "about 20 to about 30", including at least the specified endpoints.

[0077] The disclosures of all articles and references, including patent applications and publications, are incorporated by reference for all purposes. The term "consisting essentially of" used to describe a combination shall include the identified elements, ingredients, components, or steps, as well as other elements, ingredients, components, or steps that do not materially affect the basic and novel characteristics of the combination. The use of the terms "comprises" or "comprising" to describe a combination of elements, ingredients, components, or steps herein also contemplates embodiments consisting essentially of or even consisting of these elements, ingredients, components, or steps.

[0078] Multiple elements, ingredients, components or steps can be provided by a single integrated element, ingredient, component or step. Alternatively, a single integrated element, ingredient, component or step can be divided into separate multiple elements, ingredients, components or steps. The disclosure of "a" or "a" describing an element, ingredient, component or step is not intended to exclude other elements, ingredients, components or steps.

[0079] Even if there is no verbal description, the relative positional relationship of the elements depicted in the drawings is also part of the teachings herein. In addition, even if there is no verbal description, the geometric shapes shown in the drawings (although not intended to be limiting) are also within the scope of the teachings.

Claims

1. A probe body (12) for removably securing to a transmitter (34) of a single-ended optical probe (10) and inserting into a chamber or device component for measuring a desired condition, the probe body (12) comprising: a. a measuring tube (14) having a plurality of probe vents (16) adapted to allow a process fluid to flow therethrough; b. Two or more purge rings (70), each purge ring (70) comprising: i. Process window (72); ii. Purge gas inlet (78); iii. a plurality of purge gas outlet holes (80) for directing the purge gas toward or near the process window (72); c. a measuring region (15) defined by a portion of the measuring tube (14) and two or more of the purge rings (70); d. a retroreflector assembly (20) located at the end of the probe body (12), The probe body (12) can withstand a temperature of 1100°C or lower. The purge gas outlet aperture (80) is angled such that the purge gas is adapted to swirl around a surface of the process window (72).

2. The probe body (12) of claim 1, wherein the probe vents (16) are longitudinally and radially aligned in rows and columns.

3. The probe body (12) of claim 1, wherein the measuring tube (14) is formed of a material that resists sagging when exposed to temperatures of 1100°C or less.

4. The probe body (12) of claim 2, wherein the measuring tube (14) is formed of a material that resists sagging when exposed to temperatures of 1100°C or less.

5. The probe body (12) according to any one of claims 1 to 4, wherein the measuring tube (14) is formed of a material having a melting point of 1150°C or higher.

6. The probe body (12) according to any one of claims 1 to 4, wherein the measuring tube (14) is formed of a material that resists oxidation to 1100°C or higher.

7. The probe body (12) according to any one of claims 1 to 4, wherein the measuring tube (14) is formed of a nickel-based alloy.

8. The probe body (12) according to any one of claims 1 to 4, wherein the measuring tube (14) is formed of RA330.

9. The probe body (12) according to any one of claims 1 to 4, wherein the retroreflector assembly (20) comprises a retroreflector (22) having two or more reflector walls (24) adapted to reflect and / or redirect a light beam, The retroreflector (22) is formed of a material capable of withstanding a temperature of 1100° C. or lower.

10. The probe body (12) of claim 9, wherein the retroreflector (22) is formed of a material different from a material forming the measuring tube (14).

11. The probe body (12) of claim 9, wherein the retroreflector (22) is formed of an aluminum oxide material.

12. The probe body (12) of claim 9, wherein the retroreflector (22) is formed of sapphire.

13. The probe body (12) of claim 9, wherein the retroreflector assembly (20) includes a riveted seal (28) for holding the retroreflector (22) in place.

14. The probe body (12) of claim 13, wherein the rivet seal (28) and retroreflector (22) each include an engagement feature for securing the retroreflector within the rivet seal (28).

15. The probe body (12) of claim 14, wherein the engagement feature comprises a recess (26) and a bullnose feature (30).

16. A single-ended optical probe (10), comprising: a. Transmitter (34); and b. A probe body (12) according to any one of the preceding claims.

17. Use of the probe body (12) according to any one of claims 1 to 15 or the single-ended optical probe (10) according to claim 16 for measuring and / or analyzing a process fluid.

18. A method of detecting a process fluid, comprising: a. directing light in a first direction through the process window (72) of the probe body (12) according to any one of claims 1 to 15 into the measurement region (15) and through the flow of the process fluid to the retroreflector (22) of the retroreflector assembly (20); b. reflecting the light in an opposite direction in a direction parallel to the first direction via the retroreflector (22); c. pumping a purge gas into one or more of the purge rings (70); d. directing the purge gas toward or near the process window (72) through the plurality of purge gas outlet holes (80) to clean the process window (72); and e. Analyze the composition of the process fluid.

19. The method according to claim 18, wherein the purge gas flows through the probe body (12) at 2 L / min or less.

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