10 minute read
VALVES
PUMP AND VALVE INNOVATOR FINDS A TEST RIG TECHNOLOGY THAT TALKS THE TORQUE
To analyse the long term performance and reliability of hard working valves and pumps, serial innovators Manchester-based Bifold Group has adopted radio frequency based torque transducers from Sensor Technology Ltd for two of its specialist test rigs.
An inter-generational commitment to advancing science and engineering has seen Bifold transform from a 19th century mining lamp maker into a leading manufacturer of instrument valves and accessories, piping valves and pumps for the oil, gas and wider industrial markets. It has particular expertise in subsea and wellhead control systems and has also developed market leading technology in areas such as solenoid valves with ultra-low power requirements.
Its corporate development is just as impressive as its technical advancements. Over the last 10-15 years it has consistently grown profits by 50% a year, and is on course to clear £33m this year. During this period it has moved into bespoke premises, created about 250 high value jobs, developed new products and technologies and entered high tech markets around the world. Today 95% of its output is exported.
By using the power of computer aided design many of Bifold’s products are built to custom designs, yet they are produced to very short lead times thanks to the efficiency of internet communications. To maintain this standard, sample products and components are comprehensively tested so that their reliability and capabilities are never in doubt.
Bifold is as innovative in developing its test regimes as it is in advancing its product technologies and business systems. So when it wanted to assess the effects of wear on its long-life valves it set about designing a special test rig. Engineer Andrew Laverick recalls: “We wanted to measure the power required to operate the valve to see how it changed over time and with long term use. It was clear that the best way to do this was to measure the torque input over an extended period.”
TorqSense transducers lend themselves to test rig uses because they are non-contact measuring devices. Attached to the surface of the transducer shaft are two Surface Acoustic Wave (SAW) devices, when torque is applied to the shaft the SAWs react to the applied strain and change their output. The SAW devices are interrogated wirelessly using an RF couple, which passes the SAW data to and from the electronics inside the body of the transducer.
Sensor Technology’s Mark Ingham explains: “All you have to do is set up a TorqSense transducer in the test rig and fire it up. The SAW frequencies reflected back are distorted in proportion to the twist in the test piece, which in turn is proportional to the level of torque. We have some clever electronics to analyse the returning wave and feed out torque values to a computer screen.
Laverick again: “As a test engineer you are almost resigned to long set up procedures and software that falls over at the drop of a hat. But Sensor Technology has designed these problems out of their TorqSense equipment, with the result that we were able to complete our long term test procedures with the minimum amount of fuss and heartache and well within the allotted time schedule.” In fact Bifold has since bought a second TorqSense which is being fitted to a new test rig used to assess the performance of mission critical chemical injection pumps, as used at oil and gas wellheads and on process pipelines. “This project is proceeding well,” says Laverick, “and is allowing us to further develop our abilities to quickly provide bespoke equipment for ultra demanding applications, safe in the knowledge that it will perform faultlessly over a long working life.”
REDUCE FOREIGN BODY CONTAMINATION WITH GERICKE’S ROTASAFE
Gericke RotaVal have launched an enhanced version of their class leading RotaSafeTM system for their rotary valves. Designated the RotaSafe RS1 it has been developed in close cooperation with key customers.
The rotor protection system RotaSafe is designed to instantly detect any contact between the rotor and valve housing while at the same time sending a signal to the control system to isolate power to the drive motor. It will primarily be of interest to customers where product contamination due to metal to metal contact is a significant issue.
For many years Gericke RotaVal has continuously improved its foreign body and contact system. This latest version provides additional functionality, flexibility, and optimized responsiveness for the end user. The first systems have been delivered and are in full operation, protecting the process equipment and the products.
About Gericke
The Swiss Gericke Group has been designing and manufacturing equipment and systems for modern bulk material processes, as well as providing design and consultation services, for more than 125 years. Gericke bulk materials processing technology can be found throughout the world in many sectors including the food, chemical, pharmaceutical, plastics and construction material industries.
Gericke’s fully owned group companies employ more than 300 experienced professionals and are located in Switzerland, Germany, Great Britain, The Netherlands, France, USA, Brazil, Singapore, Indonesia, Malaysia, Thailand and China.
Other Valves Fight Friction, We Designed it Out
Unlike other valves that seal with friction, Posi-flate’s unique butterfly valve uses an inflatable seat to seal with air pressure. Thus it requires less torque and a smaller actuator, resulting in lower cost. Plus, the seat automatically compensates for wear, providing longer life. Some users have reported over six million cycles and the valves are still going strong.
• Less friction • Low torque • Low maintenance • Lower actuator costs • Longer valve life • More reliable
Tel: +44 (0) 1908 622366 www.posiflate.com
Tuf-Lok ring grip pipe and tube couplings are rugged, heavy duty, self-aligning and self-grounded couplings with a high end pull. They can be used for almost any application where pipe or tube ends need to be connected. The Tuf-Lok self-aligning couplings install quickly and easily with little effort.
Features
• Self-aligning • Self-grounding • High pressure rated • Full vacuum rated • Stainless or mild steel • Usable on thin or thick wall pipe or tube • Low cost • Reusable • Absorbs vibration • Externally leakproof
Tuf-Lok (UK)
Tel: +44 (0) 1706 822512 Email: sales@tuflok.co.uk • www.tuflok.com
COPERION SUPPLIES TWIN SCREW EXTRUDER TO GHENT UNIVERSITY FOR CHEMICAL PLASTIC RECYCLING
Coperion is supplying an extrusion system to Ghent University in Belgium for comprehensive research and development tasks in chemical recycling of mixed plastic waste. Coperion designed this laboratory system, built upon a ZSK 18 MEGAlab twin screw extruder, especially for chemical recycling of postconsumer waste within a throughput range of 1-10 kg per hour. Along with the extruder, it includes a feeder from Coperion K-Tron as well as a vacuum unit.
Plastic waste, especially packaging waste, is generally a mixture of materials with a high degree of contamination. Recycling this raw material is usually difficult, as sorting and cleaning of waste is in many cases neither economically viable nor technically feasible. Chemical recycling is a promising process to recycle these material streams into chemicals, waxes or liquid energy carriers.
As a trailblazer in the development of chemical recycling of plastic waste, Ghent University has laid the foundation for many forward-looking developments in the field that are paving the way to more sustainability in the plastics industry. Chemical reaction engineering in general and the kinetics of
chemical reactions are major axes of the research done at the Laboratory for Chemical Technology (LCT) of Ghent University. These include, among other applications, optimization of existing industrial processes and development, intensification and scaleup of novel technologies aimed at minimizing waste streams and energy consumption.
TWIN SCREW EXTRUSION FOR EFFICIENT ENERGY ADDITION
Coperion’s twin screw extruder technology is particularly well suited for chemical recycling of plastics. After post-consumer waste, either shredded or compacted, is reliably added to the extruder’s process section by the Coperion K-Tron feeder, a great deal of mechanical energy is introduced into the material in shortest time thanks to the continuous surface renewal as well as intensive dispersion and shearing along the twin screws.
Within about 30 seconds, a homogeneous, highly devolatilized melt with a temperature of up to 350°C is produced, into which the energy has been introduced very efficiently.
Further materials, such as catalysts, can be added and mixed in as needed. In some cases, residual water or chlorides from PVC are introduced into the extruder in minute quantities along with the plastic waste. Both are reliably extracted via vacuum devolatilization on the extruder’s process section.
Twin screw extruders possess numerous advantages that are especially beneficial in chemical recycling. The technology covers a broad range of throughputs. On larger ZSK extrusion machines, throughputs of up to 20 t/h can be realized using this process. Polymers of various viscosities are reliably plastified thanks to the highly effective mode of operation of the twin screws. Plastic energy dissipation takes place in no time. When needed, corrosion and wear protection of all productcontact parts within the process section can assure long extruder lifetime even when processing very aggressive materials.
RECLAMATION OF RAW MATERIALS
Within the reactor, the melt, which was previously heated to up to 350°C in the twin screw extruder, is further heated. At up to 500°C pyrolysis of the polymers takes place, the splitting of polymer chains into shorter units in an oxygen-free environment. The pyrolysis of polymers utilizes the random scission mechanism, where free radicals are generated. At the same time, chain reactions are initiated which lead to cracking polymers into a broad mixture of hydrocarbons in liquid and gaseous phase. The most important factors for driving this process are residence time, temperature, and the type of pyrolysis agent.
Most of the inorganic components of the postconsumer waste remain in the reactor’s sump and are removed. The polymers’ organic hydrocarbons evaporate. They are transformed into monomers, petrochemical raw materials, or synthesis gases and then processed further in a destillator into marketable products such as oil, heavy fuel, or waxes.
Chemical recycling is a very active research topic at Ghent University. Even though it is already shown that mechanical recycling of plastics is an easy method of plastic valorization, certain limitations were encountered due to the impracticality of waste separation. However, with chemical recycling, these limitations may be overcome.
The Coperion ZSK twin screw extruder will be part of a new setup for chemical recycling at Ghent University. It will be among others coupled to a vortex reactor; thus the molten plastic will flow directly into the reactor. Different technologies for the conversion of plastic waste to chemicals may be applied like catalytic pyrolysis and thermo-chemical processing (cracking).
“We are proud to be able to support the renowned Ghent University with our expertise and technology in their research and development activities involving chemical recycling. We see chemical recycling as a trailblazing process for reclaiming raw materials from mixed plastic waste. With this process we will succeed at preserving our valuable resources in the long term. As soon as the recycling system featuring the ZSK twin screw extruder is in operation at the Ghent University, it will also be available to our customers for testing,” said Jochen Schofer, Business Segment Manager for Recycling & Direct Extrusion at Coperion. www.coperion.com
