Showing posts with label TECO. Show all posts
Showing posts with label TECO. Show all posts

Magnetic Flow Meters with Specialized Construction Still the Best Bet for Dredging Applications

dredgers
Electromagnetic flow meters commonly measure slurry mixture flow on cutter suction dredgers and trailing suction hopper dredgers. These type of flow meters use exposed electrodes and non-conductive flow tubes. Ordinary magnetic flow meter flow tubes  are not designed to withstand the abrasive conditions prevalent in dredging. Standard magnetic flow meter electrodes  are prone to wear, breakage, and polarization requiring frequent re-adjustment. Standard electrode seals may also deteriorate and cause leaks and false readings.

dredgersAs an alternative, non-invasive (non-wetted) flow meters, such as clamp-on or Doppler ultrasonic flow meters, have long been proposed because of their  ease of installation and maintenance savings. However, testing of clamp-on or Doppler ultrasonic flow meters has never panned out in dredging applications. While there has been limited success on smaller sized diameters, there are few, if any, large diameter dredging pipe application success stories.

Dredging engineers always seek the simplest and most accurate method of measuring slurry flow. Considering this, there is convincing evidence that the use of customized electromagnetic flow meters, specifically designed to stand up to the rigors of dredging, look to be the best overall option.

Dredging flow meter
Dredging flow meter.
(TECO)
Dredging-specific flow meters provide wear solutions that can extend the life of equipment and keep systems at maximum operational levels. Some users report life span up to 10 years.

The dredging modifications include custom engineered ceramic brick or polyurethane liners, 3/4" stainless steel inlet and outlet protectors, independently sealed electrode wells, and field accessible Hastelloy B electrodes.

Thompson Equipment (TECO), a manufacturer of severe service magnetic flow meters located in New Orleans, will "remanufacture" any make or model of electromagnetic flow meter for dredging service. They have decades of experience servicing and remanufacturing instrumentation, and are leaders in building severe service flow meters.

Electromagnetic flow meters have always been appealing for dredging applications in terms of accuracy, resolution, and response time. Their performance problems, caused by the direct and continuous flow of abrasive slurries, are mitigated through specialized construction.  By applying electromagnetic flow meters specifically designed for the application, dredging engineers now achieve excellent reliability, long life and significant reduction in maintenance and operational costs.






Selecting the Proper Flow Meter: Other Considerations

You Get What You Pay For

Engineers and maintenance personnel who purchase flow meters should remember that accurate instruments cost more based on their features and capabilities. It is always better to search for the type of flow meter best suited to a specific application before sacrificing features in favor of lower cost.

Flow meter specifiers should also take the time to examine long-term ownership costs. It may turn out that flow meters with low purchase prices may be very expensive to maintain. On the other hand, a flow meter with a high purchase price may require little or no service, and therefore lower cost of ownership over time. Lower purchase prices do not always represent the best long term, installed value.

Know Your Process

Users need to closely evaluate their overall process conditions, which include flow rates, pressure and temperature, and operating ranges. Be cautious of lower priced alternatives whose operating parameters don't fully support the requirements of the application.

All flow meters are affected to some extent by the process media and the way they are installed. As a result, their real-time performance will often be different from the controlled reference conditions under which they calibrated. There are some general rules that can be applied to flow meters to assist in reducing uncertainty:
  • For the lowest uncertainty of measurement, positive displacement meters are generally the best option. 
  • Electromagnetic meters provide for the widest flow range and turbine meters are usually the best choice for the highest short-term repeatability.
  • Despite their high initial cost, Coriolis meters are ideal for measuring particularly viscous substances and anywhere that the measurement of mass rather than volume is required.
General Selection Concepts:
  • In general, flow meters with few or no moving parts require less time and attention than more complex flow meters. 
  • Meters constructed with multiple moving parts may malfunction because of dirt, grit or grime present in the process fluid.
  • Flow meters with impulse lines can also plug or corrode.
  • Flow meters with flow dividers and pipe bends sometimes suffer from abrasive media wear and blockages.
  • Swings in ambient temperature may affect the internal dimensions of the flow meter and could require temperature compensation.
Calibration/Recalibration

The need for recalibration of flow meters is generally a function of how well the instrument is paired to its particular application. Should the application be critical, the flow meter accuracy should be checked at frequent, regular intervals. In some instances, mostly non-critical applications, recalibration may not be necessary for a period of years, becuase the application operating parameters never change.

Keep in mind though, that no matter what flow meter technology is chosen, overall system accuracy can never exceed the accuracy of the equipment used to perform the flow meter calibration. With that said, the most precise flow calibration systems on the market employ a positive displacement design. This type of calibrator, directly traceable to the National Institute of Standards and Technology (NIST) via water draw validation, provides total accuracy of at least 0.05 percent.

For more information on flow meter selection, installation, calibration, service, and replacement contact Thompson Equipment Company (TECO). Call them at 800-528-8997 or visit their web site at https://teco-inc.com.

Magnetic Flowmeters for Measuring the Frac Fluid


A piece of equipment used in hydraulic fracturing is the blender truck. It contains the equipment used to prepare and measure the "frac fluid". Frac fluid is composed of water, sand, specialty chemicals, and gels, and is highly erosive and sometimes corrosive. This "blended" mixture of sand, water and chemicals is then injected into a well to hydraulically open cracks in the rock layers below. By opening the cracks, trapped natural gas and petroleum is released and flows more freely. 

Magnetic flowmeters are employed to measure the frac fluid flow and volume.  These flowmeters must accurately meter the frac fluid into the well, stand up to the continual erosive media, and be durable enough to handle the harsh ambient conditions. Standard process magmeters experience shortened lifespans under these conditions and must be pulled from service and repaired. A better alternative is a severe service flowmeters designed specifically for this service.

Thompson Equipment Company (TECO) manufactures an electromagnetic flowmeter (magmeter) designed for frac fluid flow metering. The TECO design incorporates two significant features to improve performance and extend operating life:
  1. A ceramic sleeved liner made of “magnesia partially stabilized zirconia”
  2. The use of solid tungsten electrodes.
The TECO fracing flowmeter provides huge benefits, namely operators save money through increased uptime, they reduce health, safety and environmental risk, and reduce costs related to magmeter replacement and repair.

TECO Proudly Supports Sky High at the Midland Permian Basin Banquet & Clay Shoot


Thompson Equipment Company (TECO) proudly supports the fantastic work Sky High does "Saving Kids. Healing Families."

Sky High's mission is to provide comfort, fund research and save lives of children fighting pediatric cancer and other life-threatening conditions at Texas Children’s Cancer Center, St. Jude Children’s Research Hospital and the Ronald McDonald House of Memphis.

TECO is proud to attend and support the "Midland Permian Basin Banquet & Clay Shoot" this past September. We strongly suggest our friends, vendors, and partners get involved with this wonderful group.

https://teco-inc.com
800-528-8997

Choosing the Right Industrial Flow Meter

Which Industrial Flow Meter
Which Industrial Flow Meter to Choose?
Choosing the right flow measurement solution can have a major impact on operational and business performance. For this reason, companies anticipating a flow meter purchase should consult with a knowledgeable instrumentation supplier, such as Thompson Equipment Company (teco-inc.com), in the early stages of a project. The effort spent learning about basic flow measurement techniques, and available meter options, will ensure a successful application once the equipment is installed.

This white paper, courtesy of Badger Meter, does a great job outlining all the various types of flow meter technologies, including:
  • Coriolis
  • Differential Pressure
  • Electromagnetic
  • Positive Displacement
  • Thermal Mass
  • Turbine
  • Impeller
  • Variable Area
  • Ultrasonic
  • Vortex
  • Oval Gear
  • Nutating Disc
Download your own PDF copy of "Choosing the Right Flow Meter here, or view the embedded document below.

https://teco-inc.com
800-528-8997 for Immediate Service

Severe Service Flowmeters by TECO

For flow measurement of extremely abrasive slurries in Mining, Dredging, Fracing, and Oil and Gas Exploration.

Capabilities include:
  • Liners: magnesia stabilized zirconia ceramic, aluminum oxide ceramic, polyurethane rubber, neoprene rubber, Linatex, Teflon (PTFE), rotationally molded Tefzel (ETFE), PFA, and others. 
  • Electrodes: SS, Hastelloy C (C-276), Hastelloy B, zirconium, titanium, platinum/iridium, solid tungsten carbide, tungsten carbide coating, etc. 
  • Exotic tube constructions available (100% titanium).
  • Specialty Coatings: epoxy paints, powder coat, custom colors, etc.
800-528-8997

Important Flowmeter Performance Metrics

Animation of differential flow
Animation of differential flow
Common to most flowmeters are rated levels of performance; some of the more universal
performance metrics include accuracy, precision/repeatability, turndown ratio, resolution, ease of installation, straight pipe run requirements, on-going operations and maintenance, and costs.

Accuracy
Accuracy is the difference between a measured value and the actual value. No flowmeter is 100% accurate and most manufacturers provide a range of accuracies in their product line - tighter accuracy requirements are typically more expensive and may also be more restrictive to specific applications.

Precision/Repeatability
The precision or repeatability of a measurement entails the ability to reproduce the same value (e.g., flow rate) with multiple measurements of the same parameter, under the same conditions.

Turndown Ratio
Rotameter
Rotameter
(ABB)
The turndown ratio refers to the flow rates over which a meter will maintain a certain accuracy and repeatability. For example, a steam flow meter that can measure accurately from 1,000 pounds per hour (pph) to 25,000 pph has a turndown ratio of 25:1. The larger the turndown ratio, the greater the range over which the meter can measure the parameter within the accuracy stated.

Resolution
The resolution is the smallest increment of flow that can be incrementally registered by the meter. For example, a water meter designed for a small diameter pipe may be able to provide a resolution of 100 pulses per gallon (or more) as a signal output, but a meter designed for a larger pipe or higher maximum flow may only be able to provide 1 pulse per 100 gallons. Further, a very large flow meter may only be able to provide 1 pulse per 1000 gallons. The metering system may have limitations with regard to peak signal frequency or minimum time between pulses to properly register the data signal.

Ease of Installation
Select make-and-model decisions considering size and weight constraints, specific electrical and communications needs, and the overall environment the flowmeter will operate in.

Magmeter
Magnetic flowmeter
(TECO)
Straight-pipe Run Requirements
Applicable to some types of fluid (gas, liquid and steam) flowmeters, straight-pipe run requirements relate to the length of unobstructed straight pipe required leading up to and immediately following the flow meter’s location. Obstructions in the fluid flow (such as elbows, tees, filters, valves, and sensor fittings) cause changes in the flow pattern (flow regime and velocity profile). Straight-pipe runs allow the flow pattern to normalize/stabilize making measurements by velocity-type and differential-pressure-type flow meters less prone to measurement error. Straight-pipe run requirements are usually expressed in terms of the number of pipe diameters.

The straight pipe requirement is in addition to the length of the flowmeter itself. The straight-pipe run requirements can be reduced with the addition of flow straightening or flow conditioning devices installed upstream.

Ongoing Operations and Maintenance
Vortex flowmeter
Vortex flowmeter
(ABB)
The lowest cost flow metering technology may not be the best choice if it has high associated maintenance costs (e.g., frequent service, calibration and recalibration, sensor replacement). As with most capital purchases, a life-cycle cost approach (including all capital and recurring costs) is recommended for decision making.

Installation Versus Capital Cost
In some situations, the cost to install a flowmeter can be greater than the capital cost; this can be true where system shutdowns are necessary for flowmeter installations, or where significant redesign efforts are needed to accommodate a flowmeter’s physical size, weight, or required connection. In these cases, decision makers should consider alternative technologies that may have a higher capital cost but a much lower installed cost. A good example of this is the use of non-intrusive flow metering technologies (e.g., ultrasonic flowmeters) that typically have a high capital cost but often a significantly reduced installed cost. It is recommended that meters be installed with isolation valves or switches making it easier to remove, replace, or service the meter in the future.

Reprinted and abstracted from US Department of Energy paper titled "Metering Best Practices: A Guide to Achieving Utility Resource Efficiency, "

Oval Gear Flow Meters: Accurate, Robust, and Long Life

Oval Gear Flow Meters Although there are many types of flow meters used to measure fluid flow rates, positive displacement (PD) designs, including Oval Gear flow meters, are unique as they are the only meters on the market that directly measure actual volume. All other metering techniques infer the volume by making a type of measurement and equating it to the flow rate.

One of the key criteria in selecting the right flow meter is the degree of accuracy dictated by the application. To meet high-precision requirements in various industrial environments, Oval Gear flow meters fit the bill. These meters feature a wide flow range, low pressure drop and extended viscosity range. Oval Gear flow meters offer easy installation and high accuracy, plus measure high temperature, viscous and caustic liquids with simple calibration.

Oval gear flow meters are simple and robust. They operate by interlocking two oval gears, offset by 90 degrees, inside the meter housing which are then rotated by the flowing media. They are very rugged and designed to operate in very harsh environments. Accuracy is maintained irrespective of temperature, viscosity change, or flow pulsation. It's not unusual to see these meters perform in the field for upwards of 40 years.
Flow path and operation of Oval Gear Flow Meter
Flow path and operation of Oval Gear Flow Meter
Oval Gear flow meters are an excellent choice for any number of industrial applications including:
  • Chemicals
  • Petrochemicals
  • Water and Wastewater
  • Oils and Diesel Fuel
  • Pulp and Paper
  • Paints and Coatings
  • Printing
Download Oval Gear flow meter brochure here.

For more information on Oval Gear flow meters visit https://teco-inc.com or call 800-528-8997.

Failed Flowmeter - Replace with New or Remanufactured?

New or Remanufactured Flow Meter
Many companies don't realize that when you have a failed mag meter or mass meter, it's often more cost-effective and efficient to have them restored to mint condition, than it is to replace them with new units.

But if you send meters to the original manufacturer they can disappear into their system for weeks or months. And you have no idea how long it will really take, or if it will fail again later from undetected problems. The fact is you can't afford the loss of productivity or downtime. But what if there were a place you could send broken flow meters that could save you money and time by restoring them to pristine condition. A cost-effective specialist who could guarantee rapid turn around time and premium customer service. A team of experienced professionals with the capabilities to keep equipment in service, even if it's no longer supported by others.

For a proven partner like this, there's only TECO. Established in 1947, TECO has become the global leader in restoration and customization of magnetic flow meters, Coriolis meters, and other process control instruments.

TECO understands that time is money, which is why they provide the fastest turnaround time in the
industry. They don't simply repair a broken part and return it, they do a full restoration and back the whole meter with a full warranty. Their quality control includes NIST traceable flow calibration, which is often required by regulatory agencies, and ISO 9000 standards. They also provide independent calibration to serve your preventive maintenance and metrology needs.

While their low cost, high quality work has made them the industry leader, it's their commitment to premium customer service that keeps their clients loyal. Extensive capabilities, combined with a focus on service, also means they can manufacture custom flow meter solutions to meet the demands of severe applications.
  • Low cost, rapid restoration of mag meters, mass meters and other instruments. 
  • Pristine, like-new equipment, backed with a full warranty. 
  • Customized solutions and expert customer service you can trust. 
It's all part of the package with TECO.

If you have failed mag meters, Coriolis meters, or other instruments, call TECO today. After receiving your equipment they'll turn around a quote in 48 hours or less - no return authorization required. To develop a customized solution for your needs, contact TECO.

Phone (504) 833-6381
Visit https://teco-inc.com

Top 5 Reasons TECO Consistency Transmitters Stand Above the Competition

  1. TECO Consistency Transmitters are shipped with built-in flow-rate compensation. This is important because blade style consistency sensors are sensitive to shifts in production flow-rate. This means that their output has a component which is strictly a function of flow-rate. If this isn’t compensated for, changes in flow-rate will look like changes in consistency. TECO Consistency Transmitters include a flow-rate input so that this flow-rate function which automatically gets applied to the consistency signal. This feature is unique to TECO.
  2. The key feature of our C3000 and C5000 probe style sensors is that they aren't sensitive to flow-rate changes to begin with. The C3000 and C5000 are insensitive to shifts in production flow-rate below 3.0 fps. This means that as long as the flow-rate stays below 3.0 fps, shifts in flow-rate will not produce any negligible affect on the probe output signal. For flow-rates above 3.0 fps when using C3/5000 series sensors, it is recommended that active compensation be used.
  3. The C5000 sensor is retractable, allowing it to be removed from an active process. This feature is particularly useful when installed in hostile measurement environments, such as blow lines and bleach plant operations. The retractable feature allows for quick change-out when it comes time for replacement, allowing the restoration of a critical measurement in minutes, instead of waiting weeks or months for a scheduled shutdown. This is a strong competitive advantage for C5000 users.
  4. All TECO sensors are hot-swappable, saving the time and effort of a recalibration procedure when a sensor is replaced. All that is required is use the built-in normalization procedure and "zero" the replacement sensor. Your new sensor is ready to use.
  5. TECO consistency transmitters can be upgraded to act as a consistency controller, or function as multi-input controller, so that other process parameters can be adjusted for in the consistency control loop.
More Reasons:
  • TECO consistency transmitters can also be set up as a dilution controller.
  • 100% Made in the USA. 
  • TECO consistency transmitters are very competitively priced.
More information at https://teco-inc.com
800-528-8997

Stock Prep Solutions - Helping Paper Manufacturers Stay in Business

Stock Prep
The concept behind stock prep is to manage the raw materials being added to the process so the finished stock meets the requirements of the paper machine and the final quality of the finished product. Finished stock is a suspension of fibers, additives, and impurities matching a defined level of quality, which ultimately determines the operation of the machinery and the quality of the final product. Most of the machines used for individual processes provide not only the desired effect, but also may produce undesirable side-effects. Implementing process controls to reduce or eliminate these undesirables help paper producers gain considerable improvements in quality, consistency, and yield.

This video introduces, and presents a case for, specific process instrumentation designed for stock prep.

http://www.teco-inc.com
800-528-8997

Positive Displacement Flowmeters

Positive displacement flowmeter.
(Badger Meter Blancett)
Positive displacement flowmeters use fluid to mechanically move internal components such as pistons, gears and discs to measure flow.  These devices are both precise and simple to operate.

The positive displacement flowmeter, in contrast with other types of flowmeters, directly measure the volume of fluid passing through the meter instead of employing inferential flow measurement. The rotational velocity of the rotor in the flow meter is directly proportional to the rate of flow. Electronic versions of positive displacement meters rely on magnets to activate sensors in their fluid chambers, whereas their non-electrical counterparts rely on the rotation being driven by the fluid flow.

The operating principle of the positive displacement meter may be simple, yet the flowmeter type offers a few specific advantages for industrial application. A main benefit of this flowmeter is a high level of accuracy due to its internal components. The accuracy of the flowmeter is directly related to the size of the clearances, or the space between the sealing faces.

These flowmeters are also particularly useful for handling a high range of viscosities. As the fluid viscosity increases with the positive displacement meter, less slippage or bypass will occur, meaning more total fluid will pass through the positive displacement meters. In addition to these design-based advantages, the positive displacement meter typically allows for excellent repeatability and linearity.

The longstanding use of positive displacement flowmeters across various industries has been a source of stability in terms of design, with the most recent advancements in positive displacement technology focusing on maintaining precision at lower costs.

There are a few known limitations for the use of positive displacement meters. The meters are not the optimal choice for measuring fluids with large particles, and are also non-ideal for measuring fluids with large air pockets. Additionally, systems using positive displacement meters need to account for slight pressure drops in the positive displacement meter. While the meters are able to accurately measure non-lubricating fluids, using positive displacement flowmeters to measure these types of liquids will not be as efficient as using the flowmeter for lubricating fluids. Overall, these types of flowmeters are a cost effective, accurate and volumetrically based flow measurement solution.

For more information on positive displacement flowmeters, call Thompson Equipment Company (TECO) at 800-528-8997 or visit https://teco-inc.com.


An Easy Way to Understand Laminar Flow vs. Turbulent Flow

Image courtesy of Wikimedia.org
Laminar flow occurs when a fluid flows in parallel "layers" with no interaction between the layers. When flowing at low velocities, fluids tend to flow without lateral (sideways) mixing, and adjacent layers glide past one another, analogous to playing cards sliding between others in a deck.

In contrast to laminar flow, turbulent flow, caused by excessive kinetic energy in parts of a fluid flow, undergoes mixing and lateral irregularities characterized by eddies, recirculation, and apparent randomness. Fluid speed magnitude and direction changes chaotically in turbulent flow.

The video below provides a very simple, but very effective, demonstration of laminar and turbulent flow.

https://teco-inc.com
800-528-8997

Get Your Worn Out Process Instrumentation Remanufactured by TECO

As the world’s largest remanufacturer of instrumentation, TECO has the experience, trained technicians, and facilities to remanufacture your equipment to meet or exceed all OEM specifications and performance standards. Send us your overworked instrument and we'll send it back to you as good as new, and ready for action!
  • All Brands
  • NIST Traceable Certificate
  • Off-the-Shelf Meters Available
  • Obsolete Meters our Specialty
  • No Evaluation Charges
  • Magmeter Customization Services
  • All Magmeter accessories
  • New Warranty
  • Failure Analysis
  • Severe Application Meters
  • Converter/Transmitter Repairs
  • Remanufacturing is GREEN

Instrument Remanufacturing, Custom Flow Solutions, Full Service Repair, Calibration, and Valve Automation Center.  https://www.teco-inc.com | 800-528-8997

World's First Magnetic Flowmeter Developed Specifically for Hydraulic Fracing

When suspended solids are mixed with a liquid (such as water), a mud-like substance referred to as a “slurry” is formed. Slurries are challenging because of their abrasive nature. Add a highly caustic or acidic condition to the slurry, and the magnetic flowmeters (Magmeters) used to measure flow become particularly susceptible to failure. In these situations off-the-shelf magnetic flowmeters won’t last, so consideration must be given to custom flowmeters built specifically to withstand the application’s unique requirements. Hydraulic fracturing (fracing) is one industry where the movement and handling of slurries is very common, and specially designed Magmeters should be used.

Thompson Equipment (TECO) is now offering their "Severe Application Meter (SAM)" (patent pending) which is specifically designed as the world's first Magmeter developed specifically for the hydraulic fracing industry. It is designed with an impact and wear resistant ceramic liner, solid tungsten carbide billet electrodes, and quick change Victaulic flanges. The SAM can also be retrofitted to the customers existing electronic secondary system, such as Rosemount, E+H, Yokagawa, etc.

For more information, contact TECO by calling (504) 833-6381 or by visiting https://www.teco-inc.com.

Understanding the Chemical Recovery Processes in Pulp & Paper Mills

chemical reclaim pulp and paper process
Figure 1
The kraft process is the dominant pulping process in the United States, accounting for approximately 85 percent of all domestic pulp production. The soda pulping process is similar to the kraft process, except that soda pulping is a non-sulfur process. One reason why the kraft process dominates the paper industry is because of the ability of the kraft chemical recovery process to recover approximately 95 percent of the pulping chemicals and at the same time produce energy in the form of steam. Other reasons for the dominance of the kraft process include its ability to handle a wide variety of wood species and the superior strength of its pulp.

The production of kraft and soda paper products from wood can be divided into three process areas:
  1. Pulping of wood chips
  2. Chemical recovery
  3. Product forming (includes bleaching)
The relationship of the chemical recovery cycle to the pulping and product forming processes is
chemical reclaim pulp and paper process
Figure 2
shown in Figure 1. Process flow diagrams of the chemical recovery area at kraft and soda pulp mills are shown in Figures 1 and 2, respectively.

The purpose of the chemical recovery cycle is to recover cooking liquor chemicals from spent
cooking liquor. The process involves concentrating black liquor, combusting organic compounds, reducing inorganic compounds, and reconstituting cooking liquor.

Cooking liquor, which is referred to as "white liquor, is an aqueous solution of sodium hydroxide (Na01) and sodium sulfide (Na2S) that is used in the pulping area of the mill. In the pulping process, white liquor is introduced with wood chips into digesters, where the wood chips are "cooked" under pressure. The contents of the digester are then discharged to a blow tank, where the softened chips are disintegrated into fibers or "pulp. The pulp and spent cooking liquor are subsequently separated in a series of brown stock washers: Spent cooking liquor, referred to as "weak black liquor, from the brown stock washers is routed to the chemical recovery area. Weak black liquor is a dilute solution (approximately 12 to 15 percent solids) of wood lignins, organic materials, oxidized inorganic compounds (sodium sulfate (Na2SO4), sodium carbonate (Na2003)), and white liquor (Na2S and Na0H).

In the chemical recovery cycle, weak black liquor is first directed through a series of multiple-effect evaporators (MEE's) to increase the solids content to about 50 percent. The "strong. (or "heavy") black liquor from the MEE's is then either oxidized in the BLO system if it is further concentrated in a DCE or routed directly to a concentrator (NDCE). Oxidation of the black liquor prior to evaporation in a DCE reduces emissions of TRS compounds, which are stripped from the black liquor in the DCE when it contacts hot flue gases from the recovery furnace. The solids content of the black liquor following the final evaporator/concentrator typically averages 65 to 68 percent.

Concentrated black liquor is sprayed into the recovery furnace, where organic compounds are combusted, and the Na2SO4 is reduced to Na2S. The black liquor burned in the recovery furnace has a high energy content (13,500 to 15,400 kilojoules per kilogram (kJ/kg) of dry solids (5,800 to 6,600 British thermal units per pound {Btu/lb} of dry solids)), which is recovered as steam for process requirements, such as cooking wood chips, heating and evaporating black liquor, preheating combustion air, and drying the pulp or paper products. Particulate matter (PM) (primarily Na2SO4) exiting the furnace with the hot flue gases is collected in an electrostatic precipitator (ESP) and added to the black liquor to be fired in the recovery furnace. Additional makeup Na2SO4, or "saltcake," may also be added to the black liquor prior to firing.

Molten inorganic salts, referred to as "smelt," collect in a char bed at the bottom of the furnace. Smelt is drawn off and dissolved in weak wash water in the SDT to form a solution of carbonate salts called "green liquor," which is primarily Na2S and Na2CO3. Green liquor also contains insoluble unburned carbon and inorganic Impurities, called dregs, which are removed in a series of clarification tanks.

Decanted green liquor is transferred to the causticizing area, where the Na2CO3 is converted to NaOH by the addition of lime (calcium oxide [Ca0]). The green liquor is first transferred to a slaker tank, where Ca0 from the lime kiln reacts with water to form calcium hydroxide (Ca(OH)2). From the slake, liquor flows through a series of agitated tanks, referred to as causticizers, that allow the causticizing reaction to go to completion (i.e., Ca(OH)2 reacts with Na2CO3 to form NaOH and CaCO3).

The causticizing product is then routed to the white liquor clarifier, which removes CaCO3 precipitate, referred to as "lime mud." The lime mud, along with dregs from the green liquor clarifier, is washed in the mud washer to remove the last traces of sodium. The mud from the mud washer is then dried and calcined in a lime kiln to produce "reburned" lime, which is reintroduced to the slaker. The mud washer filtrate, known as weak wash, is used in the SDT to dissolve recovery furnace smelt. The white liquor (NaOH and Na2S) from the clarifier is recycled to the digesters in the pulping area of the mill.

At about 7 percent of kraft mills, neutral sulfite semi-chemical (NSSC) pulping is also practiced. The NSSC process involves pulping wood chips in a solution of sodium sulfite and sodium bicarbonate, followed by mechanical de-fibrating. The NSSC and kraft processes often overlap in the chemical recovery loop, when the spent NSSC liquor, referred to as "pink liquor," is mixed with kraft black liquor and burned in the recovery furnace. In such cases, the NSSC chemicals replace most or all of the makeup chemicals. For Federal regulatory purposes, if the weight percentage of pink liquor solids exceeds 7 percent of the total mixture of solids fired and the sulfidity of the resultant green liquor exceeds 28 percent, the recovery furnace is classified as a "cross-recovery furnace.'" Because the pink liquor adds additional sulfur to the black liquor, TRS emissions from cross recovery furnaces tend to be higher than from straight kraft black liquor recovery furnaces.

With over 70 years experience, Thompson Equipment Company, Inc. (TECO) provides specialized instrumentation, magnetic flow meters, and re-manufactured process instruments used in the pulp and paper industry. For information on process control instruments, valves, or service or calibration, visit http://www.teco-inc.com or call 800-528-8997.

ifm Industrial Sensors and Control Products

ifm Temperature sensor
ifm Temperature Sensor
ifm is one of the world’s largest manufacturers of industrial sensors and controls products, producing over 9 million sensors annually. Products include position sensors, sensors for motion control, vision sensors, safety technology, process sensors, and sensors for industrial networks.

Below is ifm's complete catalog to familiarize you with their products.

For assistance with ifm products, visit TECO's website, or call 800-528-8997 for immediate service.

Understanding Coriolis Flow Measurement

Thompson Equipment
Coriolis flowmeters directly measure the mass flow of a subject fluid, which is inclusive of regular and supercritical liquids and liquefied gases. Operating on the Coriolis effect principle, Coriolis flowmeters create a controlled condition in which the mass flow of the fluid can be directly measured. They rely on motion mechanics: one or two tubes are aligned inside a Coriolis flowmeter, then made to oscillate with an exciter. Fluid flows through the oscillating tubes, twisting them slightly in proportion to the mass flow of the fluid and its inertia. There are highly reactive sensors attached to the tubes; when the measured substance flows through the vibrating tubes, the numeric difference between sensor readings provide the basis of the resulting fluid is mass flow measurement. This process also delivers a second measurement: the density of the substance. The sensors measure the frequency of oscillations. Coriolis flowmeters rely on direct computation instead of an algorithm, and therefore are regarded as highly accurate instruments in industry, coming in at 0.1 percent accuracy in some cases.
Coriolis principles
Rotation without mass flow
(image courtesy of Wikipedia).
Coriolis principles
Rotation with mass flow
(image courtesy of Wikipedia).
Coriolis flowmeters are advantageous choices for many industrial applications. They are used to measure drinking water, oils and gases, chemicals, etc. However, these mass flow measurement products particularly stand out in the chemical industry. As a prerequisite for most fluid processing operations, measurements and quantities often rely upon mass instead of upon volume. Coriolis flowmeters, with their direct measurement of mass flow, can be the optimal choice for applications requiring mass flow measurement.

As beneficial as Coriolis flowmeters are, they are not immune to some engineering and practical limitations. The most recognized limitation is the size of the pipes the meters are able to accommodate. A Coriolis meter is comparatively large, when other measurement instrument technologies are considered, making it difficult to place in some installations. In addition to being recognized as one of the most accurate flow measuring technologies, the Coriolis flowmeter requires little maintenance.
Coriolis principles
The vibration pattern with mass flow
(image courtesy of Wikipedia).
The vibration pattern during no-flow
(image courtesy of Wikipedia).

Selecting and configuring the instrument properly and assuring that installation is performed in accordance with manufacturer instructions are necessary tasks to achieving best instrument performance. Reach out to an instrumentation specialist with your flow measurement challenges, combining your process knowledge with their product application expertise to develop effective solutions.

For additional information on any industrial flow measuring technologies visit Thompson Equipment (TECO) at  http://www.teco-inc.com or call 800-528-8997.


The Magmeter Zone - Don't Let Your Flow Meters Die Here

Don't let this happen to your old flowmeters! 

Here's a video parody of the popular TV show "The Twilight Zone", only here it's the "Magmeter Zone", where old, worn out magmeters go to die. From the creative minds at TECO ... humor in magnetic flowmeters - who woulda thunk it?  Enjoy!