Most chemical facilities face ongoing demands to improve their operations. Today’s economic climate is ratcheting up pressure while making cash and resources harder to get. While there’s no “magic bullet” to bolster performance, plants certainly can achieve gains by taking advantage of new offerings from vendors. This year’s Vaaler Awards honor two products that promise significant benefits for a wide range of sites.
Every other year since 1964, Chemical Processing has presented Vaaler Awards to products and services that can dramatically improve plant operations and economics. To be considered for this year’s award, a product or service must have been commercialized in the United States between July 2007 and June 2009.
The awards are named in honor of the late John C. Vaaler, editor in chief of Chemical Processing from 1946 to 1961, and chairman of the magazine’s Editorial Board until his death in 1963.
Chemical Processing’s Editorial Board, which includes technical professionals with diverse responsibilities and from a variety of industry sectors (see below) evaluated 12 entries for technological significance, novelty or uniqueness, and breadth of applicability. This impartial panel didn’t have to bestow any awards but did judge two nominees worthy of the honor:
• Loop-Pro Version 5 from Control Station; and
• Rosemount 848T Wireless Temperature Transmitter from Emerson Process Management.
Software Speeds Control Loop Tuning
Loop-Pro Version 5, introduced in August 2008, was developed in response to customer requests for easy-to-use regulatory control tools. In particular, says Control Station, Tolland, Conn., customers wanted proportional-integral-derivative (PID) diagnostic and tuning software that didn’t demand an initial steady-state condition to produce an accurate process model and viable tuning parameters.
After all, many processes involve numerous interconnected and moving variables — keeping each of these elements “quiet” for an extended period of time can be all but impossible. Moreover, maintaining steady-state operation might result in decreased throughput, lower quality or other penalties. In addition, business-critical control loops often are highly sensitive to change and attempts to steady them can be costly.
Loop-Pro v5 doesn’t require steady-state operation before performing controlled testing. So, the software makes it easier to model and tune systems with transitional and oscillatory process data, integrating processes that are subject to drift, batch processes that exhibit highly dynamic exothermic/endothermic characteristics, and control loops with extended settling times. (For details on the software’s application at a batch processing plant, see “Loop Control Gets Easier,” www.ChemicalProcessing.com/articles/2009/027.html.)
Unlike other technologies that assume steady-state operation and calculate process models using a specific data point or the average of several data points as a given “known,” Loop-Pro v5 centers the model across the entire range of data under consideration. Because no data point gets a disproportionate weighting in the calculation and in minimization of error, v5 can optimize the model’s fit relative to all data. Freeing the model to consider all data points equally enables modeling of non-steady-state process data.
Loop-Pro v5 can handle both non-integrating and integrating processes. It enables faster and more-cost-effective tuning of non-integrating or self-regulated processes. For integrating or non-self-regulating processes, the software’s improved modeling capability permits a dramatically broader class of process behaviors to be properly modeled for controller analysis, tuning and optimization.
In addition, the software lends itself to use by both operators and technicians.
Transmitter Transforms Temperature Measurement
Monitoring condition or performance of key plant assets often demands temperature measurements. However, it’s not always easy or economical to get such data. The Rosemount 848T Wireless Temperature Transmitter, launched in May 2009, was designed to ensure measurement reliability at a reduced installed cost for applications in which multiple temperature sensors are in close proximity — such as monitoring motor bearings and windings, heat exchanger efficiency and reactor/distillation-column profiling. It combines modern multiplexing and self-organizing wireless-mesh technology to make installations simpler and less expensive. This first-of-a-kind high-density transmitter brings a revolutionary architecture to the most-measured process variable, says Rosemount, Chanhassen, Minn., a unit of Emerson Process Management.
The 848T, which is suitable for hazardous areas, can handle inputs from as many as four Resistance Temperature Detectors (RTD) or thermocouples, reducing the number of devices required. Its wireless communication obviates long sensor-wire runs, conduit, cable trays and wiring cabinets. Cost savings versus conventional installations typically run between 20% and 40%.
The device provides independently configurable inputs that support RTD, thermocouple, Ω, mV and 4–20-mA signals. It interfaces with any host using a Smart Wireless gateway. In addition, its Wireless HART capabilities extend the full benefits of Emerson’s PlantWeb digital plant architecture to previously inaccessible locations. The intrinsically safe design, coupled with enclosure options, allows installation close to any process.
The 848T is said to offer unsurpassed temperature performance and capability. Fully compensated and filtered sensor measurements ensure accuracy and repeatability in electrically noisy environments; users can configure as many as eight alerts for advanced process monitoring. The device’s robust housing easily mounts on a 2-in. pipe and can withstand harsh environments, while its five independent conduit entries simplify wiring. In addition, its low power consumption — thanks to a two-times improvement in power efficiency — ensures long battery life, six years at a 1-min. update rate.
Commissioning also is simpler and faster. The 848T’s user interface and task-based enhanced device descriptors make for intuitive configuration, plus existing HART tools can be leveraged.
Mark Rosenzweig is Chemical Processing's Editor in Chief. You can e-mail him at firstname.lastname@example.org.