Thermal Mass Flowmeter Withstands Extreme Weather Conditions
One of the earliest and longest-running test sites is located at a municipal wastewater treatment facility in the southwestern United States. The installation site conditions are particularly harsh. The ST100 flowmeter is installed completely unprotected above an aeration basin. The FCI meter is continuously exposed to direct sunlight, extreme desert heat in the summer, and the blowing dust, sand and rain of a desert winter. To compound the situation, the flowmeter is exposed to the fumes from the basin below.
The instrument installed was a typical ST100 insertion-style flowmeter calibrated to match the flow range of the aeration basin’s blower system. Its flow element is an all-welded, 316L stainless steel material with FCI’s precision equal-mass sensors with a protective shroud. It is connected to the process piping with a retractable packing gland. The electronics include triple 4-20mA with HART (Version 7) isolated outputs and digital/graphical backlit LCD, and the meter is powered by standard 115Vac mains. The electronics/transmitter enclosure is integrally mounted with the flow element and features four 0.5-inch NPT conduit ports.
The simple threaded insertion pipe connection made the unit easy to install. A permanent, laser-etched depth gauge on the flow element probe ensured proper centering of the flow element within the pipe without any separate tools.
The AC power line was run through its own separate conduit port, providing isolation and best signal integrity for the high-resolution 4-20mA current loop outputs. The 4-20mA signal is connected to the site’s SCADA system. Site electronics set-up and configuration was performed by using both the on-board keyboard and laptop computer connected to the instrument’s USB port and using FCI’s supplied ST100 Series configuration software.
The on-board display provides the site engineers with a local continuous display of all of the aeration’s process parameters, including flowrate, total flow, and temperature. The flowrate is displayed both digitally with engineering units and as a 0–100 percent bar graph. The display also has a user-writeable field to label the instrument (e.g., “Aeration Basin #4,” instrument tag number, or any other user-meaningful 17 characters). Should an alarm condition or instrument fault occur, the unit will also display informative icons and messages for the user.
The display also includes four buttons for set-up and instrument interrogation that are optically activated. Buttons activate through the glass window so there is never a need to open the unit, or decommission the area in the case of hazardous gas sites, to engage them. The display can also be rotated 90 degrees electronically, a feature the test site users described as a “very nice feature.” A unique feature of the display’s backlight is that it can be set to “always on” or to “turn on only when approached.”
Given the weather extremes, the users at this FCI test site had initially said, “The display is very nice, but we took bets that it wouldn’t last the summer.” After the summer they said, “It still looks good!”
As of this writing, this FCI ST100 flowmeter at this site has been installed and operating continuously and flawlessly for more than 16 months, enduring now two desert summers.
Two-Wire Coriolis Flowmeter Minimizes Upgrade Costs
The challenge in this particular application was that the upgrade project was already significantly over budget. The installed turbine meter had a small installation footprint and, being a two-wire instrument, utilized a shielded twisted pair for wiring. The customer realized that the cost of the piping changes and running new cabling (and conduit) for a new four-wire Coriolis flowmeter was two- to three-times the cost of the new instrument. The entire project was at risk of not happening due to financial considerations.
After a thorough search on the different Coriolis solutions from a number of manufacturers, the customer selected the Endress+Hauser Promass E200 two-wire Coriolis flowmeter. The customer selected the E200 because of its ability to use the existing wiring from the legacy turbine meter, thereby eliminating the need for new cabling and conduit. Not only was the E200 easier and cheaper to install, but it was also a step change in the measurement reliability of the device. The customer was now able to use the multivariable capability of the Coriolis flowmeter to monitor the flow, density, and totalizer via the two-wire HART communication signal.
The Endress+Hauser Promass E200 offered this customer reduced installation costs, painless integration, and zero recurring maintenance requirements. The overall lifecycle cost for the E200 Coriolis flowmeter, combined with the increased measurement reliability, made the Endress+Hauser Coriolis solution the ideal choice in this application.us.endress.com
Magmeter Meets Challenging Requirements of Water Treatment Application
Prior to using the installation of the FPI Mag, the water treatment facility was using an annubar meter located in a manhole outside of the high-lift building. This older meter was located in the plant’s underground discharge pipe. Whenever they faced issues with this meter, an entire plant shutdown was required to repair it. Recently, the water treatment plant partnered with a local engineering firm to identify and install a flow measurement solution that would eliminate the costly plant shutdowns.
Ideal for line sizes up to 138 inches, the FPI Mag is an economical flowmeter for large line sizes and reduces installed costs by up to 45 percent. While material and installation costs of conventional full-bore meters increase dramatically with pipe diameter, the FPI Mag eliminates the need for heavy equipment or extensive manpower. Installation occurs without interrupting service, dewatering lines, cutting pipe, or welding flanges.
A hot tap full-profile insertion meter, the FPI Mag combines easy installation with accurate full-profile flow measurement. Delivering accuracy unmatched by other insertion mag meters, it rivals the performance of full-bore magmeters at a much lower cost. Its highly stable profile provides accuracy of +/-1 percent of reading, +/-0.03 ft/sec zero stability from 0.3 to 20 ft/s velocity range.
The water treatment plant’s high lift building has the FPI Mag installed on one of its nine large lift pumps with positive results. The FPI Mag is particularly cost-effective for retrofit applications because of its compact insertion design that fits easily into limited-access confined spaces. It can be removed in pipes under pressure for easy inspection, cleaning, calibrating, or verification.
A key project leader from the engineering firm stated, “The advantages of the FPI Mag Meter are the functionality, accessibility and maintainability. The FPI meter works great in limited space, and having one meter for each high lift pump allows the meter to be isolated for service without an entire plant shutdown.”
The FPI Mag utilizes McCrometer’s L Series converter, featuring a six-point, curve-fitting algorithm to improve accuracy, 4-20mA (1,000 ohm) analog output, three-key touch programming, an RS485 port for easy connection to DCS, and eight-line graphical display for access to real-time and total measurements. The rugged FPI Mag is packaged in heavy-duty 316 stainless steel sensor body and its sensor is coated with NSF-certified 3M fusion-bonded epoxy coating for operational longevity. With no moving parts and a single-piece design, it contains nothing to wear or break and is generally immune to fouling. The meter comes pre-calibrated from McCrometer’s NIST-traceable lab.mccrometer.com
Precision Landfill Gas Flowmeter Improves Accuracy, Saves Valuable Field Labor
Getting the gas out of the landfill requires a collection system that draws the gas out under vacuum. Shallow vertical wells drilled into the landfill are connected to a header system and blower that carries the gas to a central collection point. Gas flow measurements are taken at various points in the system, from the gas wells to the main collection header.
Flow measurements taken at gas wells are used to determine well performance over time and to identify issues that might reduce gas collection rates, such as liquid accumulation in the well. Historically, flow has been a calculated value derived from a pressure change measured across an orifice plate, pitot tube or Venturi. These traditional flow measurement devices are designed for air and dry gases, so they don’t always work properly in the landfill environment. Landfill gas can be very warm and is fully saturated with humidity, which can clog pitot tube openings or accumulate on orifice plates and then freeze in cold climates, making accurate measurements difficult. Significant changes in flow require orifice plate diameters to be changed to get accurate readings, which can take up valuable field time and can be a difficult task in bad weather. Venturis avoid some of the problems seen with orifice plates or pitot tubes, but they often restrict gas flow at higher flowrates. Flow measurements taken at LFG wells using these traditional approaches are often highly inaccurate, biased by as much as 10–20 percent.
To solve the challenge of getting accurate gas well flow values, QED Environmental Systems saw an opportunity to apply a better method of flow measurement. QED is the leading international supplier of air-powered pumping systems for LFG well dewatering and leachate pumping and LFG flow control products. QED’s emphasis is on innovative products that reduce the total cost of ownership through ease of use, long-term durability, and technical superiority. Recently, QED partnered with Sage Metering to develop a customized version of Sage’s Prism, a battery-powered portable thermal mass flowmeter, to be used in LFG collection systems.
The QED Precision Landfill Gas Flowmeter overcomes all of the problems associated with traditional flow measurement devices. It also provides a direct reading of gas flow rather than a calculated value, corrected for temperature and humidity. The technician simply inserts the probe into the flow path through an access port attached to the pipe, selects the correct pipe size and gas mixture calibration “channel,” and a flowrate in cubic feet per minute (SCFM) is displayed. Best of all, once the reading is taken and logged into the Prism’s memory, the probe is removed from the access port – there is no-flow restriction, and the probe isn’t exposed long term to potentially corrosive trace gases and humidity. Data stored in memory can be easily uploaded to an Excel spreadsheet or to a site’s database. Initial users have recognized time-savings by eliminating the need to change orifice plates with varying flows and more accurate measurements. The QED Precision Flowmeter is a better approach for managing LFG well operations.sagemetering.com
CONTROLNext-Generation AODD Pump Designed for Harsh Semiconductor Applications
In the existing facilities, there were already several hundred air-operated double-diaphragm (AODD) pumps of various ALMATEC series. As the customer was very satisfied with them, it decided to install ALMATEC pumps in the new facilities as well. However, there was a special technical request – the manufacturer wanted to have a “One-For-All” pump version based on the functionality and structure of the FUTUR series. The pump had to be able to cope with the widest scope of various chemicals and various temperatures within the manufacturer’s applications. This applicability also needed to be valid for both the liquids inside the pump and possible fumes in the pump’s surroundings.
Therefore, the solution could only be a pump constructed of one housing material for wetted and non-wetted parts – it had to be PTFE. Due to the mechanical properties of PTFE, it was not possible to simply change all parts of the FUTUR to this material; instead, ALMATEC had to develop a new, customized pump type for the project. The development process yielded the FUTUR-OMEGA pump. It met the highest safety requirements for high-end applications:
• Entirely made of PTFE
• New construction with Ω-shaped base frame
• The design fixes diaphragm and center housing against each other
• New PTFE material for the diaphragms
• Three sizes with maximum capacities of 20, 50 and 100 l/min (5.3, 13 and 26 GPM)
All FUTUR pumps are self-priming air-operated diaphragm pumps, which may run dry. The liquid flows straight through the product chambers of the center housing, while the air control system and the air chambers are located in the side housings. This design ensures that only one part of the housing comes in contact with the liquid, reduces the number of flow bends to only two, and minimizes the surface area. The contactless cascade between the product chambers excludes the problem of sliding surfaces in the liquid with respect to particles generation and dry-running sensitivity. There is no o-ring sealing in the wetted areas.
The pumps are completely metal-free and have a compact, simple design with only a few parts. The housing parts are machined from solid blocks, the basis for a long pump life. Suction and discharge ports are located at the front, thus simplifying installation in confined spaces.
Neither piston plates nor gaskets are required for the diaphragms made of a special PTFE material. The well-balanced geometry and the characteristics of the special material lead to an extremely long lifetime. The wetted surface is small, even and without any pockets in which particles may accumulate.
FUTUR-OMEGA pumps are equipped with field-proven cylinder valves. These valves seal a large area and therefore ensure very good dry priming. They close gently and evenly and permit accurate delivery.
Due to their design, oscillating displacement pumps deliver a pulsation flow. This pulsation is considerably reduced by the appropriately designed pump. If the remaining pulsation on the discharge side is unacceptable for a specific application, pulsation dampers are available for all pump sizes.almatec.de
MFC Extends Low-Pressure Range for Specialty Gas Handling
GF120XSD is an extension to Brooks GF100 Series thermal mass flow controller family (MFC). Designed for extreme low-pressure operation, the GF120XSD has been optimized for the precise delivery of high-value, low-pressure specialty gases.
At the heart of MFC is the flow sensor, which consists of two temperature-controlled windings around a thin-walled capillary tube. As flow passes through the tube (in a precise ratio to the main flow of gas through the body of the MFC), the gas molecules carry heat down the sensor tube from the first heated zone, raising the temperature in the second heated zone. The change in temperature is directly proportional to the mass flowrate of the gas in the tube. Due to the precise sampling (or flow-splitting) the sensor output is proportional to the total flow of gas flowing through the instrument. As the sensor tube ID is typically very small (0.010” ID), and due to the fact that control valves require some pressure drop for stable control, MFC’s generally require a differential pressure of 5–10 PSID to drive the gas through the device.
In microelectronic manufacturing, a wide range of gases are used including highly toxic gases for implant and deposition processes. For safe handling, these gases are often contained in specialty cylinders that can hold large quantities of the toxic gas at sub-atmospheric pressures. This simplifies the transportation, handling and delivery of the gas, but creates challenges for the MFCs used to precisely control the flow of gas to the process chamber. As the gas is consumed, the pressure drops, causing significant challenges to traditional MFCs that require a relatively high differential pressure to drive the flow through the device.
The Brooks GF120XSD utilizes a large bore, low-pressure-drop thermal flow sensor. By increasing the conductance of the flow sensor, less pressure is required to split off the sample gas for measurement. Combined with a high-stoke precision control valve to further minimize the pressure drop, the GF120XSD can precisely control flow with <1/100th of an atmosphere of inlet pressure (and vacuum outlet pressure).
This very low pressure operation makes it possible to utilize as much as 90 percent of the valuable low pressure specialty process gases, a percent improvement over conventional MFCs.
In a recent OEM qualification, the GF120XSD demonstrated best accuracy and flow stability at very low pressures, with flow stabilization time reduced by seconds compared to previous generations of Brooks low-pressure MFCs, further improving the efficiency of gas usage.brooksinstrument.com
Self-Cleaning Acoustic Switch Provides Cost-Effective Solution to Suppress Chemical Dust Buildup
In May of 2011, Hawk Measurement installed its Gladiator Acoustic Switch for a more cost-efficient solution. The outputs from the Acoustic Switch directly turned on the chemical sprays in the coal hopper when it sensed coal. The Acoustic Switch then turned the chemical sprays off when the coal finished dumping.
According to officials at the power plant, the Acoustic Switch from Hawk has performed efficiently and continues to save the plant in both downtime and operating costs, since it started unloading coal in June of 2011.
The Hawk Gladiator Acoustic Switch can also be tested remotely through a PLC in critical applications to guarantee the switches ongoing capability. Additional alarms can be provided to support routine maintenance of the switches. The Acoustic Switch also offers a 24-month factory performance guarantee.
Hawk’s Gladiator Acoustic Switch has a maximum operating range of 500 feet, depending on the hardware selected. Applications include conveyor transfer chutes, wet and dry screens, reject screens, head chutes, crusher blocked chute switches, boom protection for stackers and reclaimers.hawkmeasure.com
Bringing Precise Flow Control To High-Pressure Gases
The most prominent challenge was the fact that metal seats used in many control valves are very difficult and expensive to manufacture and calibrate and do not seal completely, thus allowing excessive leak-by. With repeated cycling, the valve can “dimple” (dent) the seat and lead to degraded performance. This significantly interferes with the control of a wider range of pressures and flows.
Sierra’s new Smart Trak 2 high-pressure mass flow controller resolves this technical puzzle. Utilizing a unique dynamic movement (patent-pending) valve design, Sierra’s high-pressure instrument can effectively control flows at pressures up to 5,000 PSIG (333 barg) over a wide range of flows from 100 sccm to 50 slpm, with leak-by at less than 0.08 percent. By performance standards alone, this represents an order of magnitude over equivalent metal-seat controllers.
The Smart Trak 2 high-pressure controller is designed so that the physics are correct. Advanced performance results from a patented, inherently linear Laminar Flow Element (LFE) design, advanced platinum sensor technology, and a unique proprietary dynamic movement valve specifically designed for high-pressure applications. It can control flow over ranges from “5,000 PSIG in to 0 PSIG out” to “5,000 PSIG in and 4,990 PSIG out.”
The unit is available with an innovative and user-friendly Pilot Module, a front-mounted or handheld control device that allows users to “Dial-A-Gas,” change flowrate, modify engineering units, or re-configure the instrument. With the Pilot Module, the user can set zero, span and full scale for each of 10 different gases independently to accommodate unexpected application or system design changes.
With the addition of Sierra’s Compod, the Smart Trak 2 high-pressure controller transforms into a fully network-enabled MODBUS RTU device, complete with integrated programmable relays and analog inputs. By utilizing a Compod in conjunction with powerful features like Dial-a-Gas, end-users have all the building blocks to run small-scale pilot plants or control high-pressure reactors and autoclave processes without the expense of DCS or PLC systems. This makes the Smart Trak 2 high-pressure controller the most versatile and economical solution available for these challenging applications.
Pilot plants are small chemical processing systems that generate information about the behavior of the system for use in the design of larger facilities. They are often used to reduce the risk associated with construction. Since they are typically modeling chemical reactions, a mass flow controller is necessary. Used for everything from a bioreactor to a refinery, they require great flexibility and high-pressure capability. The entire pilot plant is typically heavily instrumented, therefore requiring smart controllers.
Hydrogenation is a chemical reaction between molecular hydrogen (H2) and another compound or element, usually in the presence of a catalyst. The process is commonly employed to reduce or saturate organic compounds. Hydrogenation typically constitutes the addition of pairs of hydrogen atoms to a molecule, generally an alkene. These reactions take place under high pressure. Since this is a chemical reaction, stoichiometric amounts of H2 are added. This means it must be done on a mass flow basis. Also, since the flow controller cannot realistically be calibrated for 5,000 PSIG hydrogen, it must be very linear with superb K-factor performance.
Autoclaves are industrial furnaces that operate under high heat and pressure. The curing of composite materials used in the aerospace industry is a typical example. The Smart Trak 2 high-pressure controller is used to control the flow of inert gas (typically N2) into the chamber during purge or the creation of the inert atmosphere.sierrainstruments.com
Energy-Saving Technology Reduces Air Consumption While Maintaining Flowrates
Fluid separation points at Saint Gobain are the most process-critical applications within the facility. They serve multiple functions, including recirculation and batch transfer. They run 24 hours a day, seven days a week. Over this period of time, Warren Rupp’s AirVantage Energy Saving Technology reduced air consumption by 23 percent, while maintaining Saint Gobain’s desired flowrates.
“It was simple,” said Plant Manager Rick Klok. “All we did was install the trial AirVantage pump and it did the rest, optimizing our energy consumption without special handling or monitoring.” As the pump application switched from batch transfer to recirculation to fluid separation, the AirVantage self-adjusted to the pressure drops and changing condition-points all by itself, using just the right amount of compressed air to operate our pump.
At the end of the product trial, test results showed the amount of compressed air the pump consumed with AirVantage versus data points collected prior to the product trial. “We were surprised to learn that we can save as much as $1,200 in energy costs and increase our air compressor capacity by 2.5 HP per pump,” Klok said. “We were very satisfied with the performance of the new system and we plan to use AirVantage on all AODD pumps in the future.”
AODD pumps with Warren Rupp’s AirVantage Energy Saving Technology are equipped with a microprocessor that is adaptive and continuously manages the amount of air volume required to operate the pump at desired flowrates.
This adaptive technology determines the optimal diaphragm rod velocity and relays the information to an air-distribution valve at the air inlet location of the pump. The valve acts as a gated air management system, allowing only enough air to enter each inner-pump chamber. Diaphragms perform at their optimal operating point, with less air consumption. As the pump experiences air inlet fluctuations or other changes that affect airflow, the system adapts to optimize the pump’s performance.warrenrupp.com
PTFE-Based Sealing Material Enables Leak-Free Operation In Pumping Application
In a recent application, Trelleborg Sealing Solutions teamed up with the development engineers at Flow International to further enhance the reliability and optimize performance of Flow’s HyPlex Hybrid Waterjet Cutting-Mach Series Pumps.
HyPlex pumps utilize a pressure control valve (PCV) to ensure quick reaction when changing operating pressure or opening and closing the flow of water through the cutting nozzle. The hydraulic pump pulls oil from the reservoir and pressurizes it to 3,000 PSI. This pressurized oil is sent to the manifold where the manifold’s valves create the stroking action of the intensifier by sending hydraulic oil to one side of the biscuit/plunger assembly, or the other. The intensifier is a reciprocating pump, in that the biscuit/plunger assembly reciprocates back and forth, delivering high-pressure water out one side of the intensifier while low-pressure water fills the other side. The hydraulic oil is then cooled during the return back to the reservoir.
The entire unit is designed for long life, while also designed to fail in a safe way. Waterjet systems fail gradually, rather than instantaneously. The seals and connections begin to leak slowly through specially designed weep holes. The goal was to move the equipment to a higher standard of performance, extend the seal life and reduce maintenance frequency. Turcon M12 was recommended as the material of choice to meet this challenge.
The sealing system needed to meet specified leakage control. The temperature of the rod exceeded 200 F. This rod temperature combined with a rod velocity of 112 in/min and a stroke length of 1.75 inches meant that a single sealing element and scraper was inadequate to meet the high expectations that flow demands in their equipment – optimal operation and low-maintenance designs.
Flow International’s solution from Trelleborg was a redundant sealing combination sealing system for optimal leakage control using a configuration of Turcon and Zurcon sealing elements – Turcon Stepseal 2K and a Zurcon Rimseal. The Turcon Stepseal 2K in Turcon M12 material is used as the primary seal and provides a back-pumping function. The Zurcon Rimseal is used as the secondary seal to ensure reliable sealing on a thin oil film at low pressure.trelleborg.com