Catalogue Process Cells

Process Cell Catalogue Your ProCe

About Specac At Specac, we are justifiably proud of our pedigree in providing accurate and reliable NIR, IR and FTIR sample handling accessories to academic, industrial and research institutions worldwide. Spectroscopists around the globe have depended continually upon Specac for innovative products that keep pace with the changing needs of their markets. The driving force behind our expansion and change over the years has been our commitment to achieving total customer satisfaction. Our leading-edge solutions for infrared spectroscopy have continued to deliver results in the fast-changing environments of both the laboratory and process plant. In 2015, Specac was purchased from Smiths Group by members of the executive team in partnership with the Venture Capital Trust Company, The Foresight Group. Specac now employs around 80 people, with offices in the USA and the UK and employees in China & Singapore along with a trusted network of distributors and dealers worldwide. www.specac.com |1|

Advantages of Process Cells over Probes When considering the integration of a continuous process monitoring system utilising NIR, one of the first considerations for the engineer is whether to use a probe or a process cell. On first pass it can often seem the easier option is to install a probe. However, there are several key advantages offered by process cells that are overlooked. It is important to understand the general construction and integration methods for both options. Construction & Integration The process cell is commonly installed as part of the process circuit (either directly in aProcess Stream flow pipe or as a “by-pass loop” as illustrated in Figure 1) whereas the probe is often fitted into a “T” piece in the process circuit The key difference is that the optical beam path goes directly across the process cell but is reflected back in the probe. Thus, the cell has a fibre optic input on one side of it with an optical system to collimate the beam through the sample, and a similar (usually identical) optical system on the other side to re-focus the beam onto the output fibre. In contrast, the probe typically has a single optical system that collimates the radiation from the input fibre, passing it across the sample to a mirror. The returning beam is then re-focused by the same optical system onto an output optical fibre. Instrumentation (Contains: spectrometer, communication interface for control system and reference call) Fibre-optic cable Process follows a short bypass-loop Process cell Production proven method used with many existing Specac Process cells Figure 1 illustrates a typical by-pass loop used to integrate a process cell to a process stream. The fibre optic cable can be several hundreds of metres long enabling the spectrometer to be located in a non-hazardous area. www.specac.com |3|

Vortex Liquid Cells - Type B The Vortex Type B Liquid Process Flow Cell is designed to sample industrial fluid phase streams by means of NIR, UV or Visible light. The liquid flow cell is installed directly into the plant process flow environment in a bypass loop allowing for real-time remote monitoring and control. The liquid sample stream flows through a pathlength between the Sapphire windows of the flow cell that can be operated at temperatures up to 300oC and pressures of 1500psi as standard. The liquid within the flow cell is analysed by the light passing through Sapphire windows and the light is transmitted to and from the remote Process Cell environment via fibre-optic cables. Depending on the types of fibres and spectral range of analysis, the fibre connections to a spectrometer may be as distant as a kilometre away from the actual sampling and installation point of the Type B Process Flow Cell. In accordance with the ATEX Directive for safe operation of equipment in specifically designated environments, the Type B Series Process Flow Cell may be supplied with appropriate ATEX labelling. Optional Features: Gold Diffusion bonded windows. Primary seal leak ports Window cleaning ports Protective hoods for fibre connections (I.P. 65 rated) Body Material Stainless Steel, Hastelloy, Zirconium (Others on request). Temperature Up to 300oC (280oC as standard) Pressures Up to 1500 psi Sealing Perfluoroelastomer (e.g.Kalrez 4079,Isolast 9503), Gold Diffusion Bonding + Others on Request. Flow Cell Bore DIN/ANSI Pathlengths 1 - 10 mm Optical Materials Saphire & Quartz Fibre Optic Connection SMA 905 Standard Fibre Diameter 300µm to 600µm www.specac.com |5|

Experts in Process Cells Using input from industry leading experts, Specac has been producing robust NIR process cells for more 25 years which have been installed in countless hydrocarbon processing streams containing some of the most aggressive chemicals coupled with high pressures and temperatures. Specac flow cells are available in a wide range of metallurgies, pathlengths, seal-types, optics and flow fittings, to ensure exact matching with client’s process requirements. Our flow cells operate at temperatures up to 300 °c and pressures as high as 1500 p.s.i. A choice of body materials, including Stainless Steel grades and Hastelloy® C276 are available to ensure materials compatibility with a wide range of process fluids. Special materials are available upon request. Windows can be Gold diffusion bonded to provide the highest seal integrity under the harshest of process conditions. Sapphire windows are included as standard to ensure resistance against typical corrosive process fluids. Chemically inert, perfluoroelastomer seals are incorporated in a unique dual seal arrangement to guard against the unlikely event of window seal failure. Pathlengths can be specified from 1mm to 50cm for standard configurations, and higher pathlengths are available upon request. Optical designs can be configured for near infrared (NIR) or UV-Visible regions of the spectrum, and further customisation is available for specific areas of interest. A wide range of features further enhances the performance of the range. Seal leak warning ports can be incorporated for additional process security and cells can be specified with a cleaning port to allow easy in-situ cleaning of the windows without the need to remove the cell. Protective metal hoods (to I.P. 65 rating) can be fitted over the fiber connections to guard against accidental damage. | 2 | www.specac.com

Cascade Liquid Cell - Type A The Cascade Liquid Flow Cell is designed for optical sampling of industrial process fluids in transmission mode using fibre optics. Combined with infrared or UV-VIS spectrometry our flow cells allow for real time remote monitoring and control of a wide range of industrial processes. Cascade Cells are the ideal choice for installation in plant analyser houses, enclosures or even directly on the plant. Superior optical design, state of the art sealing technology and rugged construction are combined with precision manufacturing to ensure many years or reliable, high quality performance. The Cascade Cell can operate at temperatures as high as 300°C and pressures as high as 1500 p.s.i. Body Material Stainless steel 316L, Hastellow C276, Zirconiom (Others on request) Temperature Up to 300oC (280oC as standard) Pressures Up to 1500 psi Sealing Perfluoroelastomer (e.g.Kalrez 4079,Isolast 9503), Gold Diffusion Bonding + Others on Request. Flow Cell Bore 10 mm or 16 mm Pathlengths 1 - 10 mm Optical Materials Saphire & Quartz Fibre Optic Connection SMA 905 Standard Fibre Diameter 600µm Flow Fitting ¼\", ½\" or 1' Swagelok Key Applications Oil Refining Petrochemicals Chemicals Pharmaceuticals Food Pilot Plants | 4 | www.specac.com

Typhoon Vapour Phase Gas Cell The Typhoon™ gas cell is designed to sample industrial vapour phase streams by means of NIR, UV or Visible light. The gas cell is installed directly into the plant process flow environment in a by-pass loop allowing for real-time remote monitoring and control The sample vapour stream flows through a preset, fixed pathlength (20cm or 50cm pathlengths are standard options) which can be operated at temperatures up to 300°C and pressures of 1500psi. The vapour within the gas cell is analysed by the light passing through sapphire windows and the light is transmitted to and from the remote gas cell environment via fibre-optic cable. Depending on the types of fibres and spectral range of analysis, the fibre connections may be as distant as a kilometre away from the sampling and installation point of the Typhoon™ gas cell. Optional Features: Protective hoods for fibre fittings (to I.P. 65) Window cleaning ports Body Material Stainless steel 316L, Hastellow C276, Zirconiom (Others on request) Temperature Up to 300oC (280oC as standard) Pressures Up to 1500 psi Sealing Perfluoroelastomer (e.g.Kalrez 4079,Isolast 9503), Gold Diffusion Bonding + Others on Request. Flow Cell Bore 10 mm or 16 mm Pathlengths 1 - 10 mm (10, 20 and 30 cm higher on request Optical Materials Saphire & Quartz Fibre Optic Connection SMA 905 Standard Fibre Diameter 600µm Flow Fitting ¼\", ½\" or 1' Swagelok | 6 | www.specac.com

Choosing the Cell Body Material The choice of material for the body of a Process Cell is crucial depending on the nature of the application. For most applications, one of the grades of Stainless Steel is the natural (and cheapest) choice. Typically Stainless Steel 316L is the standard choice. However, other materials are sometimes needed for improved chemical or corrosion resistance. Hastelloy® is the trademark name for a group of nickel-based alloys with varying amounts of molybdenum, chromium and other elements that give greatly improved properties in many applications. Specac offers the C276 grade as a standard material but other grades can be supplied on request. Other materials such as Titanium and Zirconium are also commonly supplied. Key Features of Hastelloy®* C276 Excellent resistance to pitting and corrosion High mechanical properties Excellent resistance to oxidising atmospheres up to 1040oC Very high resistance to many aggressive chemicals Type 316 and 316L Stainless Steels 316 316L Contains more carbon Contains less carbon More liable to weld decay better for avoiding weld corrosion Effective in acidic environments Good for high-temperature, high-corrosion resistance | 7 | www.specac.com

Choosing the Cell Window Material Almost all Specac NIR Process Cells are supplied with windows made from Sapphire – a material that has many ideal properties that make it perfectly suited for use in Process Cells. The transmission of sapphire is continuous over a broad range from the UV through to 5 µm with very little absorption – completely covering the NIR wavelength range. It is one of the strongest window materials available making it ideal for high-pressure applications. It is extremely abrasion resistant, being second only to diamond in hardness. It can be grown as a single-crystal material up to very large sizes making it very cost effective. Specac have supplied Process Cells with windows up 4” clear aperture. - and larger sizes are possible. Specac use high-purity, single-crystal material that has been cut on the crystallographic “c-axis”. This eliminates any birefringence and ensures the best optical and mechanical performance. It has exceptionally good chemical resistance, even at high temperatures, and can withstand extremely aggressive materials such as hydrofluoric acid. It has a very high melting point (over 2000 ºC) and a high thermal conductivity. It can withstand very high levels of thermal shock. It can take a very high degree of polish which, coupled with its chemical properties, mean it is less prone to fouling or having contaminants adhere to it than other materials. When compared to other commonly used window materials such as quartz (fused silica) the advantages are overwhelming and make sapphire the natural choice. | 8 | www.specac.com

Choosing a Seal Type Specac process cells are designed to withstand the rigours of process and environmental conditions whilst maintaining excellent measurement stability. Once installed, it is not just the process fluid (which may often be chemically aggressive and at high temperature) that the process cell has to survive but also occasional “extreme” situations. For example, some processes are cleaned by passing super-heated steam through the pipe work which results in enormous thermal shock to the optical elements. There will often be significant environmental stresses (e.g. wide temperature fluctuations, rain, snow, sun etc.) A critical factor for NIR process cells and probes is the interface between the optical and the mechanical body. Some form of seal must be created between these two dissimilar components to prevent leakage of the process fluid under all the operating and environmental conditions. The seal must be able to cope with the differential thermal expansion of the components as the temperature changes, along with tolerance variations from manufacture. The seal material will be exposed to the process fluid, so it also must be chemically compatible with all the constituents (including any minor or trace ones) over the full range of process temperatures and pressures. There are a wide variety of materials and designs that can be used for achieving this and their strengths and weaknesses are briefly described on the next slide. | 9 | www.specac.com

Seal Types Elastomer - For many applications, a simple and inexpensive elastomeric ‘O’ ring can perform the required functions. Typically this will be made from Kalrez 4079. ‘O’ rings are also the most common form of seal found in process cells and probes. However, as the application becomes more chemically aggressive, or operates at elevated pressures or temperatures, or reliability becomes more critical (e.g. for cost or safety reasons) the “simple” ‘O’ ring has to give way to more and more sophisticated materials and designs in order to provide acceptable performance. Diffusion Bonding - In applications where elastomer seals start to struggle (e.g. in some aggressive organic solvents or at temperatures above 250 to 300 ºC), Specac uses a diffusion bonded seal. The “seal” is a thin metallic interface between the body of the cell and a narrow region around the face of the window. The metallic inter-layer forms a bond on an atomic scale with both the body and window components. It effectively diffuses into the surfaces of the components to form an extremely strong, void free bond but also acts as a ductile layer that can cope with any mismatched thermal expansion. This makes it particularly suitable for applications that may suffer thermal shock at high temperatures. The absence of any polymer materials means that the service temperature can be as high as 500 ºC. The only limitation is the chemical compatibility of the process with the materials used in the bond. Other seal types:- Silicone-based flexible seal for high temperature applications. “Protected” or “inhibited” diffusion bonded seals. Ceramic seal compounds. Chemically resistant epoxy seals. Self-energising seals. Brazed seals. | 10 | www.specac.com

Diffusion Bonded Seals A ‘standard’ Specac process Cell will be fitted with Kalrez 4079 elastomer seals. So when and why would we provide Diffusion Bonded Seals? There are some applications where it can be difficult to find elastomer seals that will give reliable long-term performance in the environment. Equally, there are occasions where they might be reliable but extensive testing would be needed to prove it. There are also the obvious applications where the operating temperature is above the level that even high temperature elastomers can withstand (typically 280°C and above). In these circumstances, Specac can offer diffusion bonded seals which are a key enabling technology to ensure the reliable operation of our process cells in the harshest of environments. The seal consists of a thin (few hundred micron) metallic layer between the body and a narrow region (a few millimetres wide) around the outer face of the window. After processing, the metallic layer forms a bond on an atomic scale with both the body and window material. The metal layer is usually gold and the design of the bond varies depending on the body and window materials being used. The window is oriented so that the bond layer is under compression when in use – although it is extremely strong and is quite capable of withstanding tensile forces such as if the process plant is evacuated on occasions. The window material will usually be Sapphire. Body Window Diffusion Bond | 11 | www.specac.com

Other features In any optical process measurement, it is important that the windows remain clean and free of excessive fouling. Any build-up of material on the surface of the windows can result in a drop of transmitted energy to the measurement system and, also, a potential change in the shape of the spectrum which may affect the measurements being made. The use of sapphire windows helps to minimise fouling in most processes because the very high polish and non-reactive nature of the window surface make it difficult for contaminants to adhere. However, it is often desirable to have a quick and easy way to physically clean the cell windows without needing to remove the cell from the process or disturb any aspects of its optical or physical alignment. The Specac Cell cleaning port option allows this. For the Vortex & Cascade Liquid Cells a removable “plug” directly over the gap between the windows allows a test-tube brush (or something similar) to be used to physically remove any contaminants from the window surfaces. The hardness of the sapphire windows ensures that even very aggressive physical cleaning will not damage or scratch the surface. Once the cell has been isolated from the process the cleaning operation only takes minutes to perform. For reliability, the cleaning plug uses the same seal materials and designs as used for the window assemblies themselves. For the Typhoon vapour phase cell the cleaning port is usually in the form of two extra pipe connections positioned opposite the main flow pipes. The two extra pipes have blanking plugs fitted that can be removed to allow a brush to be inserted into the pipe and pushed across the surface of the window. Again, aggressive cleaning with a stiff brush will not cause damage to sapphire windows. Cleaning Port Plug Back-up Seal Process something Port Primary Seal With Back-up Ring Cleaning Port Process something Port Cleaning Port Sapphire Window Path Length | 12 | www.specac.com

Back up Seals & Tell-Tale Option Many of Specac’s liquid cells have a dual “back-up” seal design as standard. The first (or “main”) seal is an ‘O’ ring and this is the one directly exposed to the process. If for any reason this should fail and start to leak (e.g. because of attack from an unknown or unexpected component of the process fluid) a second or “back-up” seal comes into play. Specac’s philosophy is that any secondary seal should be of a different material or different design to the primary one. Otherwise, whatever caused the primary one to fail will eventually cause the secondary one to fail as well. A different material or design gives a higher probability of safety in an unexpected condition. The secondary seal in Specac’s liquid cells is a PTFE “U” lip seal which is spring-energised with a Hastelloy® finger spring. The PTFE gives outstanding resistance to a wide range of chemicals, whilst the spring maintains a continuous sealing force. The seal is also a self-energised design where any process pressure increases the sealing force on the mating surfaces. A dual back-up seal design of this type gives the highest level of reliability and safety, but in some situations, it is important to know if the primary seal has failed. For instance: When testing a seal material for compatibility in a difficult or new process. In a safety-critical application where leakage would be dangerous (e.g. a highly toxic, corrosive or inflammable fluid). Where unexpected leakage would require the plant to be shut down (e.g. if the cell was in a position where it could not be isolated and removed). For these situations Specac can provide the cell with “tell-tales”. These are small passages within the cell body that link the space between the primary and back-up seals to an outside port (usually one port for each primary/secondary seal pair). The external port can be used as a visual indication of leakage from the primary seal. If leakage is observed the user has the option of dealing with it immediately or fitting a blanking plug into the port. The latter has the effect of stopping the leak and allowing the process to pressurise the secondary seal. The user is then aware that the cell is operating on the back-up seal and needs attention at the first convenient opportunity. If the process fluid is a hazardous material, the tell-tale ports can be piped away to a safe disposal area. Usually some form of detector will be fitted in the pipe to warn the operator that a leakage is occurring. Primary Seal With Back-up Ring Back-up Seal | 13 | Tell-Tail Leak Port www.specac.com

Applications Food & Feed Distillation of natural oils Manufacturing of Acetic Acid Production of organic solvents Optimisation of destillation columns Production of Pharmaceutical intermediates Production of organic monomers Petrochemicals | 14 | www.specac.com