Friday, September 14, 2018

7 Steps for Selecting the Right Industrial Gas Detection Solution

Abstracted from the Honeywell Analytics article titled "How to Select the Right Gas Detection Solution" by Don Galman


Step 1 - Know Your Site Risks

7 Steps for Selecting the Right Industrial Gas Detection SolutionBefore beginning to consider gas detection equipment, a risk assessment needs to be conducted. Any company employing staff has the obligation to conduct risk assessments to identify potential hazards and these can include potential gas, vapor or Oxygen deficiency risks. If gas hazards are identified, gas detection is applicable as a risk reduction method.

Step 2 - Know and Identify the Primary Objective

Depending on the processes being undertaken and the gases being detected, remote or off-site alarm notification plus event data logging/reporting may also be required for Health and Safety management records. Another factor impacting on the need for enhanced reporting functions might be regulatory compliance or a condition of insurance.

Step 3 - Be Thorough and Ask the Right Questions

Having identified the primary objective, the suitable equipment is selected by asking a number of key questions. These fall into three broad categories:

  • The gases to be detected and where they may come from
  • The location and environmental conditions where detection is to take place
  • The ease of use for operators and routine servicing personnel

Step 4 - Identify the Gases to be Detected and Where They May Come From

The gases to be detected should be identified by the risk assessment, however experienced gas detection equipment manufacturers and their approved distributors are often able to help in this process, based on their experience of similar applications. However, it is important to remember that it is the end-user’s responsibility to identify all potential hazards.

It is also essential to identify the potential source of a gas release as this helps determine the number and location of detectors required for a fixed gas detection system.

Step 5 - Understand the Operating Environment

The performance, accuracy and reliability of any gas detection equipment will be affected by the environmental conditions it is subjected to. Temperature, humidity and pressure levels at the location all have a direct bearing on the type of equipment that should be selected. Additional factors such as potential variations resulting from a production process itself, diurnal/nocturnal fluctuations and seasonal changes may also affect the type of device which is suitable.

Step 6 - Understand How the Product Functions

The next area of consideration relates to additional product functionality. Aspects like wiring configuration are important, especially when retro-fitting into an existing application. If the apparatus is being integrated into a separate safety system, certain communication protocols may also be required such as HART®, Lonworks or Modbus®.

Consideration will also need to be given regarding the requirement for local displays on transmitter units and local configuration of the unit and gas displays may also be a useful addition.

Step 7 - Ease of Use

Routine maintenance is another important consideration. Some gases and vapors can be detected with a number of different sensing technologies, e.g. Hydrocarbon gases with catalytic beads or Non-dispersive Infrared NDIR. Catalytic beads do not provide fail-to-safety operation and therefore can require a high frequency of routine maintenance, however NDIR based solutions tend to have a higher initial purchase price, but may require less routine maintenance. In-house resource to undertake such routine maintenance needs to be identified and in the absence of such a resource, budgeting for third party maintenance is an important factor in selecting the right equipment.

Summary

There are many gas detection products on the market that might appear to be the same, but a closer inspection of specification, functionality and features reveals major differences in what products can do and the potential value they can offer. Similarly, individual applications are also unique in their respective designs, needs and processes undertaken.

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

Friday, August 24, 2018

A Great Solution for the Discontinued Moore / Siemens 353 Controller

Moore / Siemens 353
The Yokogawa YS1700 is a great alternative to the
discontinued Moore / Siemens 353.

For all of you who use the Moore / Siemens 353 controller and are concerned that you'll have to turn to eBay for spare parts, don't worry - we have a great solution. The Yokogawa YS1700 is a drop-in replacement for the Siemens / Moore 353.

The YS1700’s powerful function block programming allows for custom strategies to control many demanding processes such as boilers and steam generators, PH control, dosing control, and many other demanding plant processes. It offers extreme reliability and sophisticated control and includes employs dual CPUs for maximum reliability and hard-manual control for added protection.

For more information on why the YS1700 is your best bet for replacing the Moore / Siemens 353, visit this link.

Monday, August 20, 2018

New Product Alert: BLH Nobel 1756 WM Dual-channel Plug-in Weighing Module for the Rockwell 1756 ControlLogix Chassis

The BLH 1756-WM is a weighing module designed to directly plug into the Allen-Bradley 1756 ControlLogix chassis.

Intended for inventory measurement and process control, the 1756-WM offers users simple configuration and is suitable for tank, silo, vessel and hopper weighing in the United States and Canadian markets.

The weighing module seamlessly integrates weighing into the Allen-Bradley PLC by directly fitting into a single slot in the 1756 ControlLogix chassis via a screw connection plug. The weighing module is powered from the input/output chassis backplane and needs only the load cells for connection.

Once in place and set-up, calibration and configuration for the 1756-WM are simply achieved through the Rockwell RSLogix 5000® PLC Development Software; no other external configuration utilities are required. Dual independent strain gage inputs—with sense inputs for six-wire connection—power up to eight 350-ohm load cells with up to four parallel 350-ohm load cells per channel.

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