by Lee Ju Young, Senior Account Manager, South Korea, Emerson Automation Solutions

Most of us know that conductivity is an excellent way to detect the interface between a non-conductive liquid, such as a hydrocarbon, and a conductive aqueous solution. Even more impressive, however, is hearing how this vital analysis is saving time and money for real companies. Here’s a great example.

Hanwha Total Petrochemical is headquartered in Seoul, South Korea, but operates a large petrochemical complex, consisting of 13 separate plants, at Daesan, in South Korea’s Chungnam Province. The company manufactures building block chemicals that go into the making of a host of other chemicals needed for various consumer products. It starts with a naphtha cracker, yielding propylene and ethylene, which are the raw materials in the production of many of polymers, like naphtha.

The naphtha is kept in storage tanks before use. During storage, water accumulates and sinks to the bottom of the tank. Because water interferes with the cracking process, it must be periodically removed. Conductivity is ideal for monitoring the drain. The water has a conductivity between 650 and 1000 uS/cm, and the naphtha has essentially no conductivity. As the water drains, the conductivity is high. When the water/naphtha interface is present, the naphtha in the interface, being non-conductive, causes the conductivity to drop. When naphtha alone is present, the conductivity is practically zero. Thus, by stopping the drain at the first sign of a conductivity drop, the operators are ensured that only water has been drained with minimum loss of naphtha.

Prior to Hanwha Total Petrochemical’s decision to use the conductivity analyzer, draining the tank of water was manual, requiring substantial human intervention. One person was positioned at the control valve at the tank outlet to watch the water drain. This person used a visual check to make sure that only water drained out.  If naphtha was observed, the person called to the DCS to close the valve in order to minimize the loss of naphtha.

The simple addition of a Rosemount 1066 conductivity analyzer and sensors has significantly reduced the personnel hour demands on the plant’s staff, and even more significantly, has dramatically reduced leakage of costly naphtha from the tank. In addition, naphtha in wastewater increases the load on wastewater treatment and makes it more difficult to comply with environmental regulations – possibly leading to fines.

Conductivity analysis is one of the most used liquid measurements – for good reason. A simple addition of instrumentation can significantly improve the process efficiency, quality, and reliability.

The global dairy industry is growing, and one of the dairy producers’ biggest challenges is to maintain high product quality, while also increasing efficiency and minimizing waste and downtime. Recently Philip Edwards wrote an article on this topic for What’s New in Food Technology and Manufacturing titled, “Conductivity Measurement: A Hidden Key to Dairy Industry Success.” Below is an excerpt from this piece:

NZCattle2_lessgreenTo ensure this consistent product quality, the equipment used in the manufacturing of dairy products is not only made from the highest grade of material, but also needs to be cleaned and maintained in such a way as to minimize any possible contamination when changing from one product to another or from one batch to another. This process is called CIP (clean-in-place).

To remain competitive, it is important to minimize production downtime without compromising on the safety and quality of the end product. In the CIP process, conductivity measurement is used to determine how effectively equipment has been cleaned and flushed. Conductivity in CIP picks up the change in the electric conductivity of a sample stream to indicate when a flushing process has started and ended. On a rinse cycle, for example, low conductivity indicates that all chemicals in the process stream have been flushed out and it’s ready for the next batch of product.

An Interesting Case History
A major global dairy company with plants around the world was experiencing challenges with its liquid analytical systems, particularly as related to CIP. CIP systems thoroughly clean wetted components such as tanks, vessels, fermenters, process lines and inline sensors. The CIP process controlled the flow of pre-rinse, wash and post-rinse cycles, which include caustic rinse, acid rinse and water rinse cycles.

Conductivity sensors are a critical component in the design of CIP systems. The various cleaning solutions have more conductivity than the water used for flushing and final rinse. Since many systems are a ‘re-used design,’ the sensor can monitor the strength of cleaning solutions as chemicals get used up through successive cleaning cycles. Conductivity measurements can indicate the need for replenishment.

Any sensors that have to withstand CIP and sterilization must be able to function under very harsh conditions — not a simple requirement for a sensitive analytical sensor. The dairy company was experiencing up to a 50% failure rate on sensors each year, at an approximate cost of $1,200 per sensor. Much worse, however, was the cost of plant downtime — up to $100,000 per hour. The significant failure rate called the reliability of every sensor into question after a short usage period. As a preventive measure, every conductivity sensor was replaced at the end of the season, which required another CIP cycle to be performed, adding even more costs and delay to production. It was preferable, however, to the possible dumping of milk product that would have to occur in the event of a sensor failure during processing.

To learn more about the unique solution the dairy producer implemented to overcome these challenges, click HERE to read the full story.

By Rob Clemons, Sales Manager, PCE Pacific, Inc.

Hi. I’m Rob Clemons, Sales Manager for the Instrument and Automation Division of PCE Pacific, Inc. I’ve got a great customer story to share with you. Chances are, most of you don’t own cruise lines, but as you can imagine, cruise lines have very stringent water quality rules – both for potable water and for water used in recreational facilities like hot endeavourtubs. The Center for Disease Control (CDC) places strict regulations requiring the continuous measurement of both halogens, such as chlorine, and pH. So we’re very honored to have been selected by the unique cruise line, Un-Cruise Adventures, as their water quality measurement company. This selection might have implications for your application as well.

The analyzer that proved to be ideal for the Un-Cruise Adventures application is the 56 Advanced Dual Input Analyzer configured for FCL (free chlorine) measurement. The 56 is a benchmark in ease of use and met the stringent requirements of the CDC.

  • High resolution full-color screen: easily viewed process measurements and on-screen data trend graphs
  • User help screens: detailed instructions and troubleshooting in multiple languages
  • Data logger and event logger: download process data and alarm conditions with time and date stamps via USB 2.0 data port
  • Control: PID and time proportional capabilities; also includes synchronized interval timers and four special application functions
  • Digital Communications: HART® and Profibus® DP communications with full features and functions

The CDC regulations regarding measurement of halogens states:
A HALOGEN analyzer-chart recorder must be installed at a distant point in the POTABLE WATER distribution system where a significant water flow exists and represents the entire distribution system. In cases where multiple distribution loops exist and no pipes connect the loops, there must be an analyzer and chart recorder for each loop. Potable Water; 48 Data Logger Electronic data loggers with certified data security features may be used in lieu of chart recorders.

Needless to say, the choice of an electronic data logger is far superior in terms of precision, ease-of-use, and reduction in maintenance time. The CDC specifications go on to say: Operation Maintenance. A manual comparison test must be conducted daily to verify calibration. Calibration must be made whenever the manual test value is > 0.2 ppm higher or lower than the analyzer reading. Calibration (06) The daily manual comparison test or calibration must be recorded either on the recorder chart or in a log. Accuracy (05) The free residual HALOGEN measured by the HALOGEN analyzer must be ± 0.2 MG/L (ppm) of the free residual HALOGEN measured by the manual test.

The built-in data logger of the 56 again saves time, and enhances accuracy.

Un-Cruise Adventures is using the 56 equipment to provide CDC-mandated chlorine and pH control of three public hot tubs as well as for ensuring CDC compliance with onboard potable water systems on two passenger vessels. Since pH measurement is part of the free chlorine measurement on the 56, the system saved both time and money. To accommodate Un-Cruise Adventure’s space requirement, the back-panel of the assembly was trimmed down on one side and the 56 analyzer re-installed in order to fit inside a weather-proof enclosure they supplied. Our team is available to customize a system for you. Are there any water quality monitoring issues you have?

Dan Emigh, Port Engineer of Un-Cruise Adventures, stated, “I chose to use the Rosemount analytical equipment  from Emerson for this important function based on my past experiences when installing this panel  on our first vessel back in 2000. I had fantastic support from the rep and the equipment worked precisely as expected. When it became necessary to add the same type of equipment to the second vessel in 2014 I started by contacting Emerson and again received immediate and full support from the technical staff. As a direct result of the fantastic customer and technical service I have always received from everyone, I have no reason to consider anyone else for our water treatment needs. One phone call to Emerson and questions are answered, issues are resolved, and parts are on their way to our distant ships. Thanks for all the past and present support.”

And we didn’t even have to twist Dan’s arm to say that. Remember, the next time you’re sailing with Un-Cruise Adventures, the quality of the onboard water is in good hands.

What kinds of precision water quality measurement applications do you have?

By Pete Anson, Senior Product Manager, Liquid Analytical Instrumentation 

Averting regulatory violations and fines. Avoiding system disruptions. Maintaining effective monitoring in complex applications. How do you tackle these kinds of age-old plant monitoring problems? New technologies in advanced analyzers offer innovative, but simple ways to address these challenges.

56R2_data screenFor example, a unique capability of the Rosemount Analytical 56 four-wire analyzer enables continuous flow measurement and totalized volume including flow rates, in addition to pH, ORP, ISE, conductivity, and other typical liquid measurements like dissolved oxygen and turbidity. The 56 can accept pulse flow type inputs and receive 4-20mA input from any flow meter to display and output flow values to a host DCS or a PLC via raw current outputs or HART® or Profibus® communications. An analyzer that measures dual-input flow allows reporting values like flow ratio, percent recovery, percent flow ratio, flow difference 56R1_yellow info boxand totalized difference. In addition, the 56 can power and receive the 4-20mA signal from any 24vdc 2-wire transmitter. Only one AC or DC power source is needed to power the 56 analyzer, which then powers up to two loop-powered transmitters for the flow inputs and the analytical inputs.

Some examples of applications for these kinds of advanced analyzers include:

  • Monitor flow rate at an outfall point
  • Use the 56 to report blind transmitter values
  • Use the 56 to totalize flow input from a transmitter
  • Pass-through of flow values and totalized flow values to host via HART or 4-20mA outputs
  • Or do the same using wireless transmission using a THUM wireless adaptor

530The Smart Wireless THUM Adapter is a device that can retrofit on any existing two or four-wire HART device, and it enables wireless transmission of measurement and diagnostic information that was previously not available. It’s an easy way to gain access to the field intelligence already in the plant. Key benefits include:

  • Extend predictive intelligence to areas not possible before due to technical
    or economic reasons
  • Make any HART device wireless to enable new measurement points
  • Gain access to advanced instrument diagnostics
  • Remotely manage devices and monitor device health
  • Efficiently gather data from multivariable devices
  • Enable enhanced valve capabilities.

What are your ideas to utilize flow input with a four-wire 56 analyzer? Does the possibility of releasing stranded diagnostics with wireless sound like something worth investigating? We would like to hear your questions.

Measuring pH in liquids with many dissolved solids is a constant challenge for all types of industrial plants. For Kyokuto Petroleum Industries (KPI) Japan, continuous failure of their pH measurement in their desulfurization scrubber was costing significant time and money.

Image1The KPI scrubber is a magnesium hydroxide system. The pH measurement is installed after neutralization and the wastewater includes many magnesium sulfate solids. The flow chamber was sometimes clogged with solids.

KPI had been using a pH sensor with a water jet cleaning system. The cleaning system, however, was ineffective against solids that coated and plugged the glass and liquid junction of the sensor. After a few days of operation KPI could no longer trust the pH values being received as the readings would fluctuate significantly. Even when the sensor was cleaned manually, a time-consuming and expensive process, the pH sensor had to be replaced every month.

As a result, KPI often had to control the dosing of magnesium hydroxide manually based upon the experience and intuition of the operators. In addition to the cost, personnel time and extreme inconvenience, the plant was faced with significant local regulations regarding emission of SOx. If the manual control led to low magnesium oxide dosing, a SOx emission could occur with subsequent fines. If the dosing was too high, the costs of the expensive magnesium hydroxide soared and increased costs.

On top of all this, the pH sensor KPI had been using was connected to an analog device which made it impossible to get sensor status from the instrument automatically. The company could not predict sensor failure or receive other data without manual intervention.

With good reason, KPI was looking for a method of applying automatic control to its set points based on reliable pH measurement.

KPI switched their pH analysis to the Rosemount Analytical Model 1056 using the PERpH-X 3300HT-10-30 with SMART pre-amp as a sensor. The PERpH-X sensors are designed with an enhanced double junction reference that is specific to extreme applications. Reference flow into the process stream is controlled using a porous Teflon® junction that can be replaced in the event of fouling or plugging. The specially designed junction is chemically resistant and has a large surface area to maintain a steady reference signal in dirty or oily applications. This reference also resists poisoning which can occur with other sensors as a result of the diluted hydrochloric acid used to manually clean the sensor during preventive maintenance.

The 3300 has been able to operate accurately for two to three weeks before manual cleaning and the sensors are able to be used more than nine months in the process as KPI also takes advantage of the rebuildable reference feature of the 3300. The 3300 has lasted nine times longer than the previously used sensor – a dramatic improvement saving time and money.

The HART-enabled pH measurement by the 3300 allows KPI to monitor other valuable information such as reference impedance, glass impedance, temperature, etc. By monitoring these sensor parameters, KPI could detect a sudden large deposit of the reference impedance. Figure 1 shows the increasing reference impedance trend as well as the result of a sudden deposit. This information is used by KPI to improve the timing of maintenance. Image2They are also able to use temperature data to determine clogging of the flow chamber which saves both maintenance costs and prevents shutdowns. Using the Emerson 1056P-HT with a 3300HT sensor with the SMART pre-amp and jet sprayer, KPI has been able to control the dosing volume of magnesium hydroxide automatically saving time and improving efficiency. While savings in actual product costs measures in the thousands of dollars, the value of the accurate measurement is incalculable.