Employees are the most important asset of a factory. So the factory has been trying to reduce the working time of staff in hazardous areas. Automated operations can significantly reduce on-site work time. There are many potential hazards in the factory, and there are also many preventive measures that can help reduce them. One of the important measures is to minimize the number of workers working in hazardous areas or to shorten the working time in hazardous areas as much as possible. This can be achieved by reducing manual tasks, such as manually inspecting and collecting on-site instruments, observation holes, or rotor flow meters.
When measuring the liquid level of a storage tank with a dipstick, the operator needs to climb to the top of the tank and open the dipstick opening, which may come into contact with steam. Therefore, this type of work should be minimized as much as possible.
The longer the homework personnel work on site to obtain data in a timely manner, the more dangerous it becomes. The update of measurement data depends on the frequency of inspections by on-site operators, such as once per shift, once a day, once a week, or even once a month or longer. Therefore, data updates are not very frequent,
Inaccurate manual reading accuracy is also a problem. The usual accuracy of on-site pressure gauges is only 1%, and the impact of temperature changes is that every 10 ℃ will reduce the accuracy by 0.4%. After long-term use, the mechanical part of the on-site indicator instrument will wear out, and its reliability cannot be guaranteed. After the instrument is corroded, the pointer may stick and no longer change with the process, resulting in incorrect indication data and causing operators to read erroneous data for a long time without realizing it. Human factors such as reading disparity, writing errors, blurry handwriting, and data entry errors can all lead to errors.
One solution to these problems is to use wireless pressure, temperature, liquid level, and flow transmitters instead of local instruments for measurement, and transmit the measurement data wirelessly to the control room and asset management system. Data collection can be transmitted per second, per minute, per hour, or according to the needs of each application. This can reduce the working time of technicians on site, thereby reducing the danger. We know that not all measurement points require a 1-second refresh rate. So some measurement points that have never been measured before or are only recorded once a day or even longer do not need to update data every second. The refresh rate is usually set to 1 minute, which is more than 1000 times faster than daily inspections and 5 orders of magnitude higher than monthly inspections.
The basic accuracy of wireless pressure transmitters is 0.065%, and the temperature effect reduces accuracy by 0.14% every 28 ℃. Automatic data collection eliminates manual reading, recording, and input errors. The operator directly obtains measurement data from the control system. The device is equipped with built-in diagnostic components to detect the health status and faults of sensors.
The upgrade and transformation of factory automation can start with the current manual inspection and recording method for tank level monitoring. The liquid level can be measured using wireless differential pressure transmitters, wireless point type liquid level switches, or traditional radar liquid level transmitters with Wireless HART adapters. The liquid level data will be periodically transmitted to the system according to the configured frequency.
Although installing a wireless meter reader on a mechanical meter can read pointer data without the need for manual reading, issues related to mechanical meters such as inaccuracy, temperature effects, poor reliability, and lack of diagnosis still exist. In addition, it is necessary to maintain and calibrate the meter reader to ensure correct readings.
Routine maintenance relies on maintenance personnel periodically checking the health status of equipment such as pumps and motors. This includes on-site testing using portable vibration detectors, infrared thermometers, and ultrasonic detectors for water traps. Like manually reading measurement data, portable testers are also limited in their measurement capabilities. Moreover, if the pump is not continuously monitored or inspected and does not operate or reach a certain load, this is also a problem. If checked once a month, the problem may not be discovered until the next month's inspection.
Wireless vibration transmitterCan replace portable testers. The refresh rate per hour is over 700 times higher than the monthly check. Wireless monitoring can help reduce on-site inspections and also monitor vibration changes through trend monitoring.
The wireless acoustic transmitter can detect the health status of the steam trap, avoiding the need for operators to go to the site for inspection. The refresh rate of one minute is millions of times higher than the annual inspection. Acoustic transmitters can also be used to detect the status of pressure relief valves.
sampling
Another type of manual operation is to sample products or waste liquids for laboratory analysis. Manual sampling also requires on-site operations to process liquid samples.
Wireless conductivity and pH transmitters can replace these manual tasks. Other common analytical instruments can be configured with a Wireless HART wireless adapter to achieve wireless transmission.
valve
Incorrect position of manual valve switch can lead to leakage and even fire. Operators are often sent to the site to inspect the actual position of valves. Checking the position of the manual valve requires a lot of work.