Process Automation System
Encyclopedia
A process control or automation system is used to automatically control a process such as chemical, oil refineries, paper and pulp
Wood pulp
Pulp is a lignocellulosic fibrous material prepared by chemically or mechanically separating cellulose fibres from wood, fibre crops or waste paper. Wood pulp is the most common raw material in papermaking.-History:...

 factories.
The PAS often uses a network to interconnect sensors, controllers, operator terminals and actuators.
A PAS is often based on open standards in contrast to a DCS (distributed control system
Distributed control system
A distributed control system refers to a control system usually of a manufacturing system, process or any kind of dynamic system, in which the controller elements are not central in location but are distributed throughout the system with each component sub-system controlled by one or more...

), which is traditionally proprietary.
However in recent times the PAS is considered to be more associated with SCADA
SCADA
SCADA generally refers to industrial control systems : computer systems that monitor and control industrial, infrastructure, or facility-based processes, as described below:...

 systems.

PAS is the lowest level of automation, while MES (manufacturing execution system) is considered to be directly positioned above a PAS.

Process automation involves using computer technology and software engineering to help power plants and factories in industries as diverse as paper, mining and cement operate more efficiently and safely.

The background and technology

In the absence of process automation, plant operators have to physically monitor performance values and the quality of outputs to determine the best settings on which to run the production equipment. Maintenance is carried out at set intervals. This generally results in operational inefficiency and unsafe operating conditions.

Process automation simplifies this with the help of sensors at thousands of spots around the plant that collect data on temperatures, pressures, flows and so on. The information is stored and analyzed on a computer and the entire plant and each piece of production equipment can be monitored on a large screen in a control room.

Plant operating settings are then automatically adjusted to achieve the optimum production. Plant operators can manually override the process automation systems when necessary.

Process automation and energy efficiency

Factory owners want their equipment to deliver the highest output with as little production cost as possible. In many industries including oil, gas and petrochemicals, energy costs can represent 30 to 50 percent of the total production cost.

In process automation, the computer program uses measurements to show not only how the plant is working but to simulate different operating modes and find the optimal strategy for the plant. A unique characteristic of this software is its ability to "learn" and predict trends, helping speed up the response time to changing conditions.

The software and controls regulate equipment to run at the optimum speed that requires the least energy. They also ensure the consistency of quality, meaning less energy is wasted producing products that turn out to be defective, and they forecast when maintenance is needed so less time and energy is spent stopping and restarting equipment for routine inspections.

Major blocks of PAS are: microprocessors, micro controllers and micro computers, multiprocessors, LAN
Län
Län and lääni refer to the administrative divisions used in Sweden and previously in Finland. The provinces of Finland were abolished on January 1, 2010....

s, SCADA
SCADA
SCADA generally refers to industrial control systems : computer systems that monitor and control industrial, infrastructure, or facility-based processes, as described below:...

, RTUs (remote terminal units) and analog and digital I/O modules
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK