While direct insertion probes eliminate sample loops and sample systems and their associated problems, sometimes it is necessary to install sample loops for safety, service, and/or sample conditioning reasons. Consequently, whenever direct insertion probes are not appropriate and the process material does not require the added assurance of a High Safety Flow Cell a Multi-Purpose Flow Cell (MPFC) is used.
Multi-Purpose Flow Cell (MPFC)
The MPFC is a convenient, compact, rugged sample interface that is easy to install and even easier to service. The cell’s sapphire windows can be cleaned by simply removing a clean-out plug for direct access to the windows without disconnecting process lines or fiber optic cables.
Multi-Purpose Flow Cell Design Features
- Simple, Serviceable Design
- Dual Sealed for Added Safety / Reliability
- Process Resistant Construction – 316L stainless steel, C-276 Hastelloy and other alloys available
- Variety of o-ring Materials – Viton, Kalrez®, EPDM, etc.
- Exceptional Light Transmission -Typically, peak transmission exceeds 50% for more signal and lower measurement noise, which translates to lower limits of detection
- Heated Version available -used to maintain the temperature of a preconditioned sample
- Compatible with a variety of fiber optic analyzers, according to fiber diameter and spectral range
Multi-Purpose Flow Cell Pathlengths and Operating Range
- Standard Pathlengths: 1, 2, 5, 10, and 20 mm
- Temperature Ranges: 0 °C to 300 °C (o-ring material dependent)
- Pressure Ranges: 0 to 500 psi (o-ring durometer dependent)
- Certified version is available that is rated to 1000 psi
High Safety Flow Cell (HSFC)
The High Safety Flow Cell (HSFC) was engineered for applications involving extremely hazardous materials. When processes involve extremely toxic or hazardous materials such as hydrofluoric acid, phosgene, isocyanates, etc., safety is paramount. Uncontrolled or undetected leaks cannot be tolerated. Designed with leak prevention and early detection in mind the HSFC is built into a Class 300 flange, using welded construction and double o-ring sealed sapphire windows. A weep or “tattletale” port connects to the space between the o-rings and when coupled to a sensor, can indicate when the o-rings are in need of replacement. The HSFC is available in a variety of alloys and o-ring materials selected to be compatible with the process.
A passage from between the o-rings is brought to a common port terminated in a ½” Class 300 flange. It is highly recommended that a sensor sensitive to the process material be attached to this port with its alarm set at an appropriate level. An alarm condition would indicate that the first o-ring seal has failed and that immediate o-ring service is required. The second o-ring seals the process until the required service is accomplished. Welded construction is used to connect the warning port. All HSFC’s are hydrostatically tested prior to delivery.
The early warning leak port is terminated in a ½” Class 300 flange. O-ring material must be specified by the customer to ensure process compatibility. Please consult appropriate resources for temperature specifications of various o-ring materials and chemical compatibility with your process.
The High Safety Flow Cell can be dismantled for o-ring replacement and cleaning. Repeatability of the pathlength on re-assembly is ensured by the design. Additional o-rings are used to prevent infiltration of environmental contaminants such as water, vapor, and dust.
High Safety Flow Cell Design Features
- Suitable for extremely hazardous sample streams
- Built into a ½” Class 300 flange – High Safety Flow Cell is a 2.25″ thick, 1″ class 300 flange
- Patented double o-ring sealed design on each sapphire window
- Safety sniffer port provided between o-ring seals. This allows connection to a leak detection system to be used as an indicator of primary seal failure
- Compatible with a variety of fiber optic analyzers, according to fiber diameter and spectral range
High Safety Flow Cell Pathlengths and Operating Ranges
- Standard Pathlengths: 20 and 30 mm. Other pathlengths are available
- Temperature Ranges: 0 °C to 150 °C [300 °F]
- Pressure Ranges: <300 psig [2000 kPa] (hydrostatically)
Heated Multi-Purpose Flow Cell (HMPFC) for FT-NIR
Some applications such as nucleation reactions, polymer cross-linking or high viscosity fluids require that the temperature of the fluid be precisely controlled to ensure that the reaction proceeds as expected and passes through the flow cell. If the temperature drops, the fluid may solidify in the low cell or the polymer chain may not be the correct length. In these cases the Multi-Purpose Flow Cell (MPFC) is also available as a heated version (HMPFC).
The flow cell is drilled to accept a heating or cooling fluid. While the heat exchanged is not sufficient to significantly impact a rapidly flowing sample, it can be used to maintain the temperature of a preconditioned sample. The Multi-Purpose Flow Cell also has a dual seal at the sapphire “window-to-process” interface. This doubles protection for the expensive internal optical lens.
Heated Multi-Purpose Flow Cell Design
- Suitable for many installations in side streams or sample conditioning systems
- Suitable for use where temperature control of sample is desired
- Threaded chamber is provided for the circulation of heating or cooling fluids
- Collimated beam for excellent light transmission
- Clean out port for easy window cleaning
- Dual Seal for added safety
- Compatible with a variety of fiber optic analyzers, according to fiber diameter and spectral range
Heated Multi-Purpose Flow Cell Pathlengths and Operating Ranges
- Standard Pathlengths: 1, 2, 5, 10 and 20 mm
- Temperature Ranges: 0 °C to 300 °C (o-ring material dependent)
- Pressure Ranges: 0 to 500 psi (o-ring durometer dependent)
- Certified version is available that is rated to 1000 psi