Top 9 Smart Plant Productivity Hacks

I figured I should share how smart plants are improving their process operations and productivity by minimizing field operator rounds and other manual tasks. How does a digital plant architecture help save people’s time around the plant and reduce cost for the company? Here are my personal thoughts:

Smart plants are now deploying more sensors to improve productivity and process operations. The most practical and cost effective way to deploy large numbers of additional sensors is to use digital networks such as wireless and existing fieldbus networks. This way no additional 4-20 mA wiring need to be laid, no IO cards installed, and no spare IO channels used.

An instructing fact is that in most plants built on fieldbus, the fieldbus network segments are rarely fully loaded to their 16 device capacity. For instance, a particular network may only have 8 devices which means another 8 devices can be connected up to the same field junction box – and each device can support multiple measurements such as one fieldbus temperature transmitter handling 8 sensors. This translates into a lot of additional I/O capacity. Wireless is a good addition to both fieldbus and hardwired plants. A single wireless gateway can handle 100 devices – and each device can support multiple measurements such as a wireless temperature transmitter handling 4 sensors. A gateway in each plant unit is a good architecture. Again, this translates into a lot of additional I/O capacity.

Productivity

Many plants have great control systems, yet there are still many tasks carried out manually such as field operator rounds. Digital networking makes it possible to automate and do away with many of these time consuming duties.

Operator rounds

Field operators manually collect data around the plant at each shift, daily, or weekly by reading mechanical instruments like pressure and temperature gauges, from sight level glasses, variable area flow meters, or even using a dip stick. A clipboard or handheld terminal may be used. In any case, I personally believe using people for data collection is non-productive, slow, and there is potential for error. There is also an element of personnel safety to this. Fortunately, automating manual operator rounds with sensors is easy with wireless or fieldbus and results in greater productivity as well as more accurate and timely data for a more predictive operation.

Local Control Panel (LCP)

A particular case of mechanical pressure gauges is at the Local Control Panels (LCP) from which operators start and stop pumps, fans, and compressors manually in the field. In this application replacing the mechanical gauge with a wireless pressure gauge transmitting to the historian or DCS for indication, trending, and alarming enhances the situational awareness around manual procedures for the operators in the control room, and entire crew, to reduce mistakes. At the same time a large dial gauge is provided on the field instrument, supporting local operation.

Offsite tank farm storage tank

Tank farms with storage tanks are typically located away from the control room. Many tanks farms were built with little or no instrumentation due to the high cost of running 4-20 mA and on-off wiring for each individual signal for long distances. As a result operations must go all the way to the tank farm and climb each individual tank to get the data. This is very time consuming. By modernizing the tank farm with digital networking, a tank can be fully instrumented with little or no wiring. This improves productivity at minimal cost. It is easier to keep up with all the tasks.

Wellhead

Wellheads in onshore well pads are generally spread widely over large geographical areas. Offshore wellheads are often on unmanned satellite platforms. Power supply is typically an issue. Many wellheads have either no instrumentation at all or rely on chart recorders for just a few variables. Operations, management, and optimization rely on personnel traveling to each wellhead to take reading from mechanical gauges and collecting recorder charts which have to be interpreted and manually entered into software. This is not very productive as personnel spend a long time driving to site or in transport via helicopter or boat. There is an element of risk in these travels as well. Wireless sensors are a simple way to instrument both production wells and injection wells. Eliminating travels improves productivity as personnel spend less time traveling to get the data, but can instead spend their time acting on what the data tells them. People save time and the company saves money.

Wellhead Control Panel (WCP)

On offshore platforms the Wellhead Control Panels (WCP) for subsurface safety valves, master, wing, choke and gas lift valves are generally located by the wellheads, away from the central control room. WCPs are pneumatic and hydraulic, often only with mechanical instrumentation without connection back to the central control room for monitoring. Checking on the status require operators to come to the WCP. These WCPs can now be modernized with wireless sensors to monitor loss of pressure or leaks in pneumatic and hydraulic systems, hydraulic fluid level, and shutdown status etc. reported to the control room. That is, the WCP remains pneumatic and hydraulic, but enhanced with wireless for monitoring. This saves times and enabled faster remedial action on failures.

Offsite standby pump

The cooling water intake facility is usually also located away from the control room. Just like for the storage tanks in a tank farm, the pumps are rarely instrumented due to the high cost of running 4-20 mA and on-off signal wires. Therefore field operators are required to do inspection rounds to check on pumps in automatic standby arrangement with local controls to see which pump is operating and which is stopped and why. By using wireless transmitters, the operating status of pumps can be communicated to the control room without using wires. This saves times and improves productivity, as well as reveals pump issues sooner.

Process Operations

The process and operators at the DCS console also benefit from pervasive networking and pervasive use of sensors.

Valve and damper position

Due to the high cost of 4-20 mA and on-off signal wiring and associated DCS I/O cards, the control valves, on-off valves, dampers, vanes, louvers, and other actuated equipment were often not fitted with actual position feedback when the plant was originally built. This means operators have no way of confirming the valve or damper is actually moving correctly, if it is limited in its movement, or even completely stuck. Such problems would impact control performance. Therefore operators need actual position feedback to uncover if a valve is unable to open fully or if the lover arm is bent out of shape – to ensure it gets corrected in order to restore production performance. This is somewhat similar to feedback for manual valves covered in the HS&E essay.

Rotating kiln and reactor

Rotating kilns, combustion chambers, dryers, and reactors etc. all revolve around their axis and all need instrumentation for monitoring, principally to get a temperature profile to detect hot spots that could damage the equipment. Traditionally 4-20 mA instrumentation has been used, but since the equipment is revolving a slip-ring has been used between the moving and fixed part. These slip-rings suffer wear and tear. Slip-rings are prone to failure which results in loss of measurement and visibility for the operators, which is very disruptive. By instead using wireless instrumentation the slip-ring is bypassed solving this problem. The operators get a trustworthy measurement for monitoring and control.

Process troubleshooting

From time to time there will be issues with pumps and valve sizing or other process problems that requires troubleshooting. Using 4-20 mA instrumentation process troubleshooting was very difficult and the idea often abandoned because running temporary wiring to temporary installed instrumentation was not practical. Wireless instrumentation solves this problem. Once a plant has a wireless sensor network infrastructure, wireless sensors can easily be installed any time for ad-hoc short-term engineering trials to solve process problems. The wireless sensors just drop-in as needed: pressure, differential pressure, vibration, position, level, or temperature etc. The data can be integrated with the DCS or historian, but in many cases a simple HMI software may be used just for the trial until the root cause of the process problem has been found.

Next Step

These are just few of the digital productivity hacks I have come across. If you have seen others or have some ideas, please share. By putting digital networking (bus or wireless) to good use, plants can make more effective use of scarce manpower. Personnel can spend less time collecting data and more time acting on the information. Well, that’s my personal opinion. If you are interested in how the digital ecosystem is transforming process automation click “Follow” by my photo to not miss future updates. Click “Like” if you found this useful to you and share it with others if you think it would be useful to them.