Wireless Marches On...
The use of wireless technology to reduce engineering and construction costs while increasing productivity is being realized by more and more chemical companies. In that vein, Emerson has added a number of new products and solutions, including full redundancy, which enables further wireless adoption for control and critical monitoring applications.
New wireless products consist of an adapter that enables wireless transmission of previously unattainable measurement and diagnostic information for existing field devices. Another significant new wireless product is a position monitor capable of reporting the positions of valves. Both can be easily joined to existing WirelessHART networks transmitting data through Smart Wireless gateways to control system hosts or asset management software.
Redundancy For Wireless Monitoring & Control
Wireless is readily deployed for monitoring, and process manufacturers have asked for redundancy for control and critical monitoring points. Emerson has enacted a unique approach to redundancy for Smart Wireless monitoring and control solutions. Available with the DeltaV™ S Series digital automation system, full redundancy protects the wireless network from any single point of failure by allowing primary failover to ensure that data is always delivered even if there is a malfunction.
The utility of Smart Wireless for control over WirelessHART networks was recently demonstrated at bioprocess technology supplier Broadley James, where WirelessHART pH and temperature transmitters control a single-use disposable bioreactor. “We conducted batch runs using mammalian cell culture,” says Scott Broadley, Broadley James president. “The observed pH and temperature control using wireless measurements was equivalent to that achieved using wired transmitters.”
Many HART® instruments in chemical plants are rich with process and diagnostic data that goes unused because it cannot be accessed by older legacy systems unable to receive HART communications. With a wireless adapter, any two- or four-wire HART instrument can now be upgraded easily and inexpensively to transmit measurement and diagnostic information through a WirelessHART network with 99.9 percent reliability.
Emerson’s new Smart Wireless THUM™ adapter easily and cost-effectively enables a new level of field intelligence to control and predictive maintenance systems. For example, online monitoring for device alerts allows users to recognize potential failures and avoid problems before a major upset can occur.
When applied on digital valve controllers, wireless adapters make it possible for control valve technicians to perform in-service testing, alert monitoring and valve position trending—all without going into the plant. Knowing the true condition of control valves permits planners to reduce the number of valves removed for service during maintenance periods, resulting in savings.
At the Chevron Phillips chemical plant in Sweeny, TX, wireless adapters are adding to the capabilities of flowmeters that are used to measure product transfers between the plant and an adjacent petroleum refinery. According to an instrument measurement planner, “This has made it possible for operators to launch meter verification from the control room rather than making trips to the field. The adapters also act as repeaters for other wireless devices being added to the wireless network.”
Wireless Position Monitors
Wireless position monitors are useful additions in chemical plants where many manually operated or semi-automatic valves, safety relief valves, etc. are not able to provide position feedback. This is usually due to the cost of installing wiring, the remote location of the valves or both. Often, it’s impossible to determine the actual position of these valves without going into the field and attaching an external instrument.
Wireless position monitors are also credited with saving $75,000 at Harcos Chemicals of Kansas City, KS, by helping to prevent three product release incidents. Harcos employs manual valves in remote and hard-to-reach locations for sampling, directing, injection and extraction processes. Previously, operators had to enter hazardous areas or climb ladders.
AOC, a manufacturer of resins, gel coats, colorants, and additives for composites and cast polymers, uses Smart Wireless to continuously monitor resin batch temperature. The wireless solution eliminates clipboard rounds that were an inefficient use of operators’ time, subjected personnel to safety risks and lengthened time to market.
In a Total Petrochemicals plant in France, eight wireless temperature transmitters were mounted directly on the exterior of a boiler drum in order to monitor the condition of a steam-cracked boiler and help determine when it may need to be replaced. The result is a better understanding of the boiler’s condition, as well as increased safety in the boiler room due to the reduction of movement of personnel into and around the at-risk areas.