Papermaking is a non-stop manufacturing process, so the continuity and powerful manipulation of the production line is essential for maintaining the quality of the end product. There are many challenging flow measurements to consider in a Pulp and Paper mill, from inventory flows, competitive chemicals, abrasive materials, and excessive method temperatures, to various steam first-class and fuels.

For effective flow measurement in the mill, selecting and installing the right technology and configuration is critical – and this is where the electromagnetic flow meter comes into play. This specialized flow meter is necessary for measuring and controlling the flow rate of the slurry in the pulp supply system, ensuring that the production process runs smoothly and efficiently.

What is an Electromagnetic Flow Meter?

Electromagnetic flow meters, also known as magmeters, are highly accurate and reliable flowmeters ideal for many applications. With their ability to measure flow rates between one and thirty feet per second in conductive fluids, magmeters offer better than one accuracy of indicated flow rate. This incredible accuracy is partly because the magmeter measures the average velocity of the fluid in the entire pipe rather than just a single point. This is made possible through Faraday’s Law. When a moving conductor (the fluid) passes through a magnetic field perpendicular to the flow, it creates a minimal current on a set of electrodes at right angles. This current is proportional to the average velocity of the fluid in the pipeline.

Magmeters are ideal for measuring clean liquids like water and fluids with both dissolved and suspended solids. They are also highly accurate when measuring slurries such as lime and chemical solutions, which are often corrosive and abrasive. This makes magmeters perfect for applications that require precise and reliable measurements in harsh environments.

Electromagnetic Flow Meter for Pulp and Paper Industry

This is why they’re the fundamental workhorse within the pulp and paper industry. An electromagnetic flow meter is an essential tool for the pulp and paper industry, as it measures water flow in various locations within the mill. These flow meters measure black, white, and green liquors, pulp stock, paper machine flows, and different chemical flows, including chlorine dioxide, hydrogen peroxide, sodium hypochlorite, and more. With its robust design and highly accurate measurements, the Basic Workhorse Flow Meter is an indispensable asset for any pulp and paper operation.

Magmeters use a lining to protect their coils and electrodes from grounding on the pipe body. For simple applications like water, neoprene is commonly used as the liner, and a nickel alloy electrode is sufficient. However, for highly corrosive fluids, Teflon® linings and corrosion-resistant metals like titanium are usually the best choices for the electrodes. This ensures that your magmeters are well-protected against the corrosive effects of the fluid.

Magmeters were designed with an AC signal to excite the coils, which created a sine wave output from the electrodes. However, a problem soon arose: when the fluid being measured was anything other than water, deposits would build up on the wetted surfaces of the electrodes, causing the sine wave to drift and resulting in a decrease in flow measurement accuracy. To address this issue, newer magmeter designs use a DC signal to excite the coils, allowing for more accurate and reliable flow measurements.

Key Production Processes

The slurry supply system comprises three key production processes: disintegration, beating and mixing.

During the disintegration process, an electromagnetic waft meter is used as it should degree the flow rate of the slurry and ensure its stability in the subsequent beating process. This helps optimize the efficiency of the grinding disc, stabilize the slurry and solution degree, and ultimately improve the quality of the beating. In addition, the electromagnetic flow meter and the regulating valve form a PID (proportional-integral-derivative) regulating loop, further enhancing the effectiveness of the grinding process and the consistency of the slurry entering the disc. This ultimately leads to improved quality and performance of the beating.

The pulping process is essential to ensure the quality of paper products.

• The concentration and proportion of the pulp must remain constant, with a fluctuation of no more than 2%.
• The pulp must be stably supplied to the paper machine to ensure the regular operation of the paper machine.
• A certain amount of slurry must be reserved to adapt to changes in paper machine speed and varieties.

To ensure the flow control of the pulp, an electromagnetic flow meter is installed at the outlet of the pulp pump for each type of pulp. The pulp flow is then adjusted through a regulating valve to ensure that each pulp meets the process requirements. This adjustment of the slurry ultimately results in a stable and uniform slurry ratio.

Summary

Electromagnetic flow meters are widely used throughout the mill in various applications, from stock, liquor, chemicals, lime mud, and water. They are a reliable and cost-effective solution for measuring flow, offering accuracy, obstruction-less measurement (fiber does not build up in meters), a range of materials for configuration, no ports or impulse lines for non-plugging, and full diameter with no pressure drop across the meter. Additionally, these meters are available in sizes from fractional through sizes larger than 36 and require minimal maintenance.

The post How Does An Electromagnetic Flow Meter Work in Pulp and Paper appeared first on InstruthinkGroup.

As a professional in engineering and instrumentation, it is essential to consider various factors when selecting a thermocouple for temperature measurement.

Here are five things you should know about industrial thermocouple assemblies to make the most of them.

What is a Thermocouple?

A thermocouple is the world’s workhorse for measuring temperature. They are reliable, versatile, long-lasting, inexpensive, and reply quickly to temperature changes.

Thermocouples are temperature-sensing devices composed of two metal conductors connected to the measuring junction (hot junction) at one end. The conductors are not in contact at the other end, forming the reference junction (cold junction). The resulting electromotive force (emf) difference between the two junctions is calibrated to provide accurate temperature readings. Thermocouples are available in various calibration types depending on the metals used for the positive and negative conductors.

When choosing an industrial thermocouple for temperature measurement, it is important to consider more than just the operating temperature range and the environment or media in which it will be used.  Professional engineers should take into consideration the compatibility of the thermocouple with the device, the accuracy of the measurements, the response time, and the power requirements of the thermocouple.

However, there are different issues to preserve in thoughts whilst measuring temperature with a thermocouple assembly.

Five Factors to Consider

1. Reference Value

A thermocouple measures temperature by detecting the difference in electromotive force (emf) at its two junctions. Since this measurement is relative and not absolute, the temperature of the cold junction must be known to determine the actual temperature at the hot junction. Fortunately, modern industrial thermocouples have a separate sensor built into the temperature transmitter to measure the ambient temperature at the reference junction, making this compensation easy.  This ensures a precise, professional measurement, saving time and effort.

2. Connection

When connecting a thermocouple sensor, it is important to ensure that the polarity of the wires is correct. If the positive and negative wires are switched, the polarity will be reversed, and the reading will be incorrect or negative. This is one of the most common causes of thermocouple temperature measurement errors. Therefore, following the thermocouple’s specifications is essential when connecting the wires. Note: In many electrical systems, red designates positive polarity.

However, for thermocouples in the United States, the red wire is the negative wire. Professional technicians should take great care to ensure that the wiring is correctly connected to avoid errors and ensure accuracy in temperature readings.

3. Galvanic Isolation

Galvanic isolation is a crucial component of temperature measurement. When the temperature sensor is mounted in the field and grounded, it can be exposed to ground potentials that differ from the measuring instrument in the control room. This can cause currents and sparks that can damage the instrument – Galvanic isolation prevents this from happening. With a temperature transmitter featuring galvanic isolation and an isolated output, you can be sure that your measuring instrument is protected from potential damage.

4. Sensor Break Monitoring

Monitoring sensor breaks with thermocouple assemblies are a great way to sound an alarm when a circuit opens. However, even in ideal conditions, connections can come loose in the ceramic terminal block due to vibration, falsely triggering the alarm. Additionally, ceramic terminal blocks can be prone to breakage, making it important to monitor them closely. By taking the necessary steps to monitor sensor breaks, you can help ensure that your circuit operates at its best.

5. Linearity

A thermocouple’s voltage–temperature curve is non-linear, meaning that low-quality transmitters which draw a straight line between the upper and lower limits can create inaccuracies in the readings.  To ensure accuracy, high-quality temperature transmitters use a process known as linearization, which calibrates the voltage along the curve for greater accuracy. This results in a more accurate temperature reading, ensuring that the correct temperature is always recorded.

Advantages

For many applications, a thermocouple is an ideal choice for temperature measurement. With its high-temperature resistance, reliable accuracy, fast response time, and extreme durability, thermocouples offer a range of advantages:

• Thermocouples can be used under demanding environmental conditions
• They have a high degree of reproducibility and accuracy over a wide operating range
• Thermocouples have a fast response time and a wide temperature range
• Their self-powered design means they do not require current or voltage sources
• Thermocouples are highly resistant to vibrations and shocks, making them a durable and reliable choice.

Limitations

Although thermocouple probes are an excellent choice for many applications, they have a few limitations. For one,

• They are not as accurate as RTDs in specific temperature ranges and can also experience drift over time.
• Thermocouples are more susceptible to corrosion if the insulation is not up to par.
• The thermocouple signals may not be perfectly linear.

However, these limitations do not necessarily disqualify thermocouples as a viable option. Thermocouples can still be an excellent choice for many applications with the proper maintenance and care.

Conclusion

Thermocouples are an excellent choice for temperature measurement due to their versatility, responsiveness, ruggedness, and low cost. When selecting a thermocouple for temperature measurement, it is crucial to consider various factors to ensure the best-suited thermocouple is chosen for the application.  Thermocouples can provide reliable and accurate temperature measurements for many years with the right selection and proper care.

Email us at sales@instruthink.com or visit our website at www.bcsgroup.com for inquiries.

The post What are the Factors to Consider When Measuring Thermocouples appeared first on InstruthinkGroup.

Measurement of the air and other gases in chemical process industries (CPI) production facilities is essential for various reasons, including safety, process control, product quality, production efficiency, environmental compliance, and cost.  Major accidents, emergency shutdowns, unplanned maintenance, production slowdowns, and cost overruns are all possible outcomes when measuring inaccurate or unreliable air or other gases.

The use of flow measurement technology in CPI operations is currently limited to the most basic type of measurement: volumetric flow. Only about half of the possible methods for measuring gas flow are suitable for heavy-duty metering applications, and even then, there are other considerations that affect their use. For example, one technology may be more accurate at measuring a specific type of material than another, or it might require more space. In addition, depending on what materials need to be measured and how much accuracy is required, each technology has its advantages and disadvantages.

When choosing a flow meter for gas measurement jobs in CPI plants, the expression “information is power” becomes a key consideration. This is because the same flow-sensing technology selected for one application in a plant may be the wrong choice for another application, even though they are close by. Your choice of flow-sensing technology will determine how well you can monitor those applications.

In the manufacturing industry, measuring the flow of gases and air is vital for a proper product. If the wrong flow meter is selected, the cost of picking it can be in the thousands of dollars. It’s also essential to choose the right type of flow meter for your application.

The cost of failing to perceive minor differences in air and other gas flow measurement systems may be penalized in the event of security incidents, poor product quality, production delays, or difficulties in respecting the environment.

Pros of Vortex Technology

Vortex flow meters offer many advantages to flow measurement, including easy installation with no impulse lines, no moving parts to service or repair, reduced leak potential, and a wide range of lower flow rates.   Vortex meters also offer low power consumption, allowing for use in remote areas.

Additionally, Vortex meters are unique in that they can accommodate liquid, gas, steam, and corrosive applications. Vortex flow meters are also able to withstand high process temperatures and pressures.

Vortex flow meters are well suited for various applications across various industries, including oil and gas, refining, chemical and petrochemical, and food and beverage.    In addition, vortex flow meters also excel in steam-related applications, including steam injection and steam measurement for district energy systems and industrial plants.

How Does It Work?   

Vortex flow meters measure fluid velocity using an operating principle called the von Kármán effect, which states that as the flow passes through a stubby body, a repeating pattern of swirling vortices is generated.   In a vortex flow meter, an obstruction in the flow path, often referred to as a shedding bar, serves as a strain. The shedding bar causes the process fluid to separate and form zones of alternating differential pressure called vortices around the back face of the shedding bar.

The vortices cause a small sensing element behind or inside the shedding bar to oscillate at a specific frequency. The velocity of the working fluid is directly proportional to the frequency of the vortices generated by the shedder bar’s unique geometry. The volumetric flow can be calculated with the pipe’s known section. Vortex flow meters often utilize a pressure and temperature sensor to achieve a compensated mass flow measurement.

Common Measurement Applications

Gas flow meters are often required to comply with IEC 61508/61511 (SIL) as part of a Safety Instrumented System in many applications. These systems must be designed and installed per this standard, which requires them to be designed to withstand extreme pressure, shock, and vibration conditions. The following sections cover four typical and complex gas flow measurement applications in chemical facilities.

GAS DISTRIBUTION METERING

Gas distribution meters measure the number of gases in a process stream or system. These meters are also called flow meters and displacement meters. This instrument measures the differential pressure between two points in a stream of gas utilizing a calibrated glass tube or column filled with liquid. The pressure differential causes the liquid to rise within the tube until it reaches its equilibrium with ambient pressure. At this point, it is displaced upward through an outlet valve into an analyzer at a constant rate that depends on flow rates through the meter and volumetric flow rates in both pipes.

FLARING SYSTEM

Flaring systems are necessary for many chemical processes’ safe and efficient operation. They use a variety of gases to move massive amounts of specific gases, such as nitrogen, argon, and oxygen, for inert ions, purging, or blanketing. Other gases, such as hydrogen, would be needed as a catalyst. Accurately measuring these gases is necessary for process control, inventory control, and cost management.

TANK BLANKETING

Tank blanketing is filling a tank with inert gases to displace air or other gases to protect sensitive equipment from corrosive or explosive atmospheres. Most tanks require large volumes of nitrogen, argon, and oxygen to create inert gases that are less reactive than air and allow the tank to be filled safely with liquid chemicals. Some tanks may also require purging by pumping out the inert gas before filling the tank with chemicals.

STACK GAS MONITORING

The stack gas monitoring system (SGMS) is a one-stop shop for environmental compliance. Its components include multiple flow sensors, blowers, and scrubbers, all required to measure plant waste gases’ discharge through huge stacks with scrubber systems. EPA 10 CFR 40 and 40 CFR 98; EUROPEAN UNION. Directives 2003/87/EC and 2007/589/EC.US MMR 30 CFR Part 250, Subpart K, Section 250, and others are among the standards that must be met by Continuous Emission Monitoring Systems (CEMS).

GAS FLOW CHALLENGES  

Gas flow measurement is critical for process engineers to maintain accurate fluid flows, which can be affected by pressure drops caused by cross-flow and back-pressure. Gas flow measurement must be accurate, reliable, and repeatable. The ability to measure gas flow accurately requires that the measuring equipment has an accurate flow rate range and resolution for each component in the system.

LOW AND HIGH FLOWS

It’s essential to be aware of low-flow conditions to perform routine maintenance and catch leaks quickly. When the network is malfunctioning, you’ll need a vortex flow meter that can measure high flows and has a wide operating range.

METER CALIBRATION

Vortex flow meters must be calibrated for hydrocarbon composition gases and customized to match the specific process conditions for an accurate reading.

LARGE LINE SIZES

When pipe widths increase, the number of flow meter technologies is reduced. Specific considerations are then needed for selecting a flow meter for longer lines.

AVAILABLE STRAIGHT RUN

All velocity-based flow meter systems necessitate straight-run pipes on both sides of the meter. This is to ensure that a reliable measurement is taken. However, it can be challenging to fit this in busy production or processing environments.

LIMITED ACCESS

Insertion-style meters are often inserted into or retracted from a process using a ball valve, which means that the meter is quickly inserted or retracted. Compared to this type of meter, spool-style flow meters can require lengthy shutdowns and high maintenance costs for removal and insertion.

Conclusion

This article has covered the basics of using a vortex flow meter to measure nitrogen flow. While there are other ways to measure nitrogen flow, the vortex flow meter is one of the most accurate and reliable methods. If you need to measure nitrogen flow for any reason, we hope this article has given you the information you need to get started. Contact sales@instruthink.com, or visit our website at www.instruthink.com to learn more.

The post How to Measure Nitrogen Flow with a Vortex Flowmeter appeared first on InstruthinkGroup.