Monday, August 13, 2018

Condition Monitoring Systems Provide Improved Performance, Safety & Profits: A Video Presentation

From large turbine generator protection to general-purpose equipment, rotating machinery provides critical and non-critical functions in plants across many industries in the USA. To avoid unnecessary downtime, plant operators turn to condition monitoring systems to monitor the health of these machines. Vibration is one of several important parameters that may lead to the early detection of machine trouble. Operators can benefit from efficient maintenance and avoid unscheduled downtime by performing periodic or constant monitoring of vibration.

The video below provides a quick overview of the performance, maintenance, safety, and profitability benefits that condition monitoring systems provide to plants who implement their use.

https://arjaynet.com
(800) 761-1749

Saturday, July 21, 2018

Measuring Flue and Exhaust Gas Flows in Large Stacks

Generally speaking, Flue or Stack gas is the exhaust gas resulting from any source of combustion. Typical commercial sources of these gases are ovens, furnaces, boilers or steam generators and power plants. The need to accurately monitor, measure and report on the exhaust from commercial combustion systems is increasingly required by environmental regulations and the resulting company policies. The need to do this reliably, and at the same time economically, can be a challenge unless the correct instrumentation is used.

The composition of flue or stack gas depends on the type of fuel that is being burned, but nitrogen (N2) derived from the combustion air is typically at least two-thirds of gas mixture, with carbon dioxide (CO2), water vapor (H2O) and excess oxygen (O2) making up the balance. The exhaust gas from even well-designed combustion systems will also contain a small percentage of a number of pollutants such as particulate matter (soot), carbon monoxide (CO), nitrogen oxides (NOx), and sulfur oxides (SO2). Typical ranges of these components for a gas-fired system are 74% N2, 7% CO2, 15% H2O, 4% O2, 200-300 ppm CO and 60-70 ppm NOx. For a coal-fired system they are 77% N2, 13% CO2, 6% H2O, 4% O2, 50 ppm CO, 420 ppm NOx and 420 ppm SO2.

The gases inside the stacks are much hotter — and therefore less dense — than the air outside of the stack. This difference in pressure is the driving force that “pulls” the required combustion air into the combustion zone and then moves the flue gas up and out of the stack. This movement of combustion air and flue gas is commonly referred to as the "natural draft" or "stack effect" though other terms are also used. Taller stacks produce more draft and the stacks for industrial applications can be quite large to facilitate both the intake of air for combustion as well as the dispersal of the flue gases over a wide area. The dispersal of the flue gas is necessary to reduce the overall concentrations of pollutants to acceptable levels in the surrounding atmosphere.

Continuous emission monitoring systems (CEMS) have been used for quite some time as a means to provide information for industrial combustion controls. To accomplish this, the systems monitored the flue gas for O2, CO and CO2. This basic function has been expanded in recent years to incorporate compliance with governmental regulations for air emission standards. In addition to the “traditional” gases, a CEMS that is used for environmental reporting now monitors emissions of SO2, NOx, mercury (Hg) and hydrogen chloride (HCL) as well as airborne particulate matter and volatile organic compounds (VOCs). The most common methods of sampling, analyzing and reporting used by the CEMS are dilution-extractive systems, extractive systems and in situ systems, with dilution-extractive systems being the most common.

In conjunction with the gas sampling, the overall gas flow rate must also be measured and accurately reported to get a complete understanding of the combustion process and the resulting stack emissions. However, measuring the flow rate in large stacks presents its own set of challenges. Uneven, irregular flow profiles across the large stack diameters are more common than not, and must be dealt with adequately to achieve the necessary accuracy in the overall flow measurement. The large diameters of these stacks make most common methods of flow measurement impractical, ineffective or prohibitively expensive. What is required to meet this challenge is an effective measurement technology in an instrumentation package with low operating costs and a variety of installation options.

Thermal Technology

Constant temperature thermal mass flow meters, such as those produced by EPI, operate on the principle of thermal dispersion or heat loss from a heated Resistance Temperature Detector (RTD) to the flowing gas. Two active RTD sensors are operated in a balanced state. One acts as a temperature sensor reference; the other is the active heated sensor. Heat loss to the flowing fluid tends to unbalance the heated flow sensor and it is forced back into balance by the electronics. The effects of variations in density are virtually eliminated by molecular heat transfer and sensor temperature correction, eliminating any need for additional instrumentation to provide true mass flow measurement.

Multipoint Systems

Multipoint Systems are designed to measure gas flows where two or more sensing points are required due to large cross-sectional areas such as exhaust and flue stacks. The EPI Series 9000MP Multipoint Systems are installed throughout the world, providing customers with years of steady, reliable service. Coupled with Air Purge System (APS), the Series 9000MP Multipoint Systems are now well-suited to an even greater variety of industrial applications.

The Series 9000MP Multipoint System includes one or more Series 9000MP Probes and a Series 9601MP System Control Panel (SCP). The probe assembly typically has two or more flow sensors mounted in a 11⁄2" OD probe shaft. The 9000MP probe’s sensors are removable for field replacement if one is damaged. Each sensor is matched to its own digital microcontroller. Communications between the probe assemblies and the SCP are transmitted via an integrated Modbus RTU network. The SCP includes its own microcontroller for system-level control and flow display. The SCP provides 0–5 VDC and 4– 20mA analog output signals. The 4–20 mA grand average output can drive up to 1200 ohms. RS232 & RS485 Modbus RTU communications are also supported for unprecedented access to the overall system, — including each individual sensor — for programmable Fail Safe operation and multiple options for flow signal recovery from a sensor failure.

The optional Air Purge System (APS) supports the cleaning of the sensors in applications where particulates cause problems. The frequency and duration of the purge cycle can be controlled externally or by using the Master-TouchTM software. The system can also be set to maintain the flow rate at its current level when the purge was activated. This important option preserves the integrity of the flow rate and elapsed total data which might otherwise be compromised by the flow of the purge gas.

Whether used in conjunction with a CEMS installation or as a standalone answer for accurate stack or exhaust gas measurement, the Eldridge Products, Inc. Series 9000MP Multipoint Systems are known for accurate, economical and reliable performance over many years of active service life. With addition of the integrated Modbus communications and the optional Air Purge system, the Series 9000MP gains even greater power and flexibility.

For more information on Eldridge Products thermal mass flow sensors, contact Arjay Automation by visiting https://arjaynet.com or calling (800) 761-1749.

Reprinted with permission from Eldridge Products, Inc.

Thursday, July 12, 2018

Arjay Automation: Skilled Engineers Solving Problems in Flowmeters, Toxic /Combustible Gas Detection, Process Weighing, and Analytical Measurements

Arjay Automation specifies, sells and supports instrumentation for measurement and control in Minnesota, North and South Dakota, Wisconsin and the North Central United States. Arjay differentiates themselves from other companies through it's team of skilled engineers who are experts in solving problems in the application of flowmeters, toxic and combustible gas detection, process weighing, and analytical measurements.

The video below explains the kinds of process control products Arjay Automation provides:

Monday, July 2, 2018

Happy Independence Day from Arjay Automation!


"One flag, one land, one heart, one hand, One Nation evermore!" 

Oliver Wendell Holmes

Tuesday, June 26, 2018

EasyTREK / EchoTREK Ultrasonic Level Transmitters for Liquids

EasyTREK - EchoTREK Ultrasonic Level Transmitters for LiquidsUltrasonic level metering technology is based on the principle of measuring the time required for the
ultrasound pulses to cover the distance from the sensor to the level of the media being measured and back. Echoes bouncing back from the surface of the process media reach the sensor surface after the time of flight of the ultrasonic impulse. With the help of the customizable tank dimensions or the pre-programmed flume / weir parameters, the time of flight of the reflected signal is measured and processed by the level control electronics, and presented as distance, level, volume or flow proportional data.

NIVELCO’s EasyTREK and EchoTREK high performance level transmitters are built upon 30 years of experience with ultrasonic level measurement. EasyTREK and EchoTREK transmitters are an excellent choice for liquid level measurement in sumps or tanks, or open channel flow measurement. Installed on the tank roof, or above the liquid surface to be measured, the transmitters have an analog output proportional to liquid level or can transmit a HART digital signal. Additionally, local readout is provided by a plug-in display which can be removed when not needed.

Review the embedded document below, or you can download the EasyTREK / EchoTREK Ultrasonic Level Transmitter PDF brochure by clicking this link.

Tuesday, June 19, 2018

Industrial Vibration Monitoring

Vibration Monitoring
Vibration Monitoring
All you have to do is drive in a car to understand that failing mechanical systems create symptoms that can be detected by our sense of feel. Vibrations in the steering wheel may indicate bad steering linkage. Transmission wear may manifest as loud or hard gear shifting. Exhaust systems that have come loose may be felt as in the floorboards as vibrations. All of these have one thing in common - degradation of a mechanical device beyond design specifications to the point of creating abnormal levels of vibration.

What is vibration?

Vibration is defined as “an oscillation of the parts of a fluid or an elastic solid whose equilibrium has been disturbed.”

Asset Monitoring on Large Equipment
Asset Monitoring for Large Equipment
Most important to understand is that vibration is motion, and that motion cycles around a position of equilibrium. Simply touch a running machine and you know if it's running or not, because the machine's motor creates a vibration which is transmitted to the other areas of the machine. In some machines, many parts can be rotating simultaneously, with each contributing it's own unique pattern of vibration. Human touch merely senses the sum of all these vibrations because touch is not sensitive to distinguish the individual differences. Vibration detection instrumentation and signature analysis software can sort out the various vibration components using sensors to quantify the magnitude of vibration, and more accurately determine how rough or smooth the machine is running. Vibration amplitude and the magnitude of vibration is expressed as:

Vibration Sensor
Sensor
Acceleration – The rate of change of velocity. Recognizing that vibrational forces are cyclic, both the magnitude of displacement and velocity change from a neutral or minimum value to some maximum. Acceleration is a value representing the maximum rate that velocity (speed of the displacement) is increasing.

Velocity – The speed at which a machine or machine component is moving as it undergoes oscillating motion.

Displacement – Also known as “peak-to-peak displacement”, this is the total distance traveled by the vibrating part from one extreme limit of travel to the other extreme limit of travel.

A variety of sensors are available that will sense vibrational displacement, velocity or acceleration, and provide a proportionate, measurable output signal. Applying these sensors depend largely on the machine condition with the help of limited guidelines published to determine the relative running condition of a machine.

Sensor Installed on Motor
Sensor Installed on Motor
Vibration signature analysis can be used in defining the exact machine location of the vibration and what component of the machine is in need of repair or replacement. When the vibration magnitude exceeds a predetermined value, sensors and software can narrow down the individual vibration signals and separate them via vibration magnitude and frequency. Combined with a little machine design understanding, a person schooled in vibration signature analysis can interpret this information to define the machine problem down to a component level. However, there are no guidelines to determine the absolute  limits of failure or indefinite life for machines. It is simply not possible to establish absolute vibration limits. Predictive maintenance programs are intended to establish severity criteria or limits above which action will be taken and monitor the overall condition of machines.

Vibration monitoring and analysis is used to uncover and predict a wide variety of problems related to rotating equipment, such as:
Predictive analysis for wind turbines
Predictive analysis for wind turbines.
  • Sleeve-bearing problems
  • Gear problems
  • Unbalance
  • Belt drive problems
  • Eccentric rotors
  • Flow-induced vibration problems
  • Rolling element bearing problems
  • Mechanical looseness/weakness
  • Misalignment
  • Resonance problems
  • Electrical problems
  • Rotor rub

Determining or predicting the presence of these problems is difficult, but asset monitoring technology is advancing quickly. As progress is made, modern manufacturing and production facilities can look forward to tremendous safety advancements and large cost savings through reliable and accurate predictive failure analysis.

Contact Arjay Automation to discuss your vibration and asset monitoring requirement. You can find them at https://arjaynet.com.

Wednesday, June 6, 2018

A Pressure Transmitter Design with Overpressure Protection

Overpressure Protection
Overpressure Protection Design
Overpressure can cause a pressure transmitter to fail or impair its performance. This effect happens when excessive differential pressure is applied to the device which is greater than its measuring range. Overpressure can occur from improper manifold sequencing, startup and shutdown conditions, or a sudden process upset. Yokogawa's unique capsule design equalizes overpressure within the capsule before it can reach the measurement sensor. Therefore Yokogawa's pressure transmitters prevent failure and minimize any performance impact from overpressure events. Overpressure protection provides
  • Increased reliability from reduced failures
  • Improved long-term stability in real-world conditions
  • Reduced maintenance costs through fewer unscheduled calibrations
The video below demonstrates how this is done.

For more information, contact Arjay Automation by visiting https://arjaynet.com or calling (800) 761-1749.