Sterling Systems & Controls, Inc. provides process controls and automation systems for a wide variety of industrial applications. One such application is the recycling tires. When something is “recycled” the entire recycled item is converted into usable materials. In the case of recycling tires, this is the case. Sterling Systems has completed several projects where it was the provider of the process control and automation of the process of converting old tires into usable materials such as oils, gases, and carbon. The process is a modified version of pyrolysis, a thermal decomposition of materials at high temperatures in an inert atmosphere such as a vacuum or nitrogen.
Primary automation components
The reactor process is controlled by a process control automation system designed and provided by Sterling Systems & Controls, Inc. Often multiple reactors are produced and operated together. The process control automation system for this recycling tires application includes a desktop PC with dual monitors, a PanelView Plus 6 running Rockwell’s FactoryTalk View ME (machine edition) automation software, and custom engineering and software by Sterling Systems. Also included is the PLC/Motor Starter control panel, which houses the PLC, main disconnect breaker, motor starters and the variable frequency drives for the reactors. Sterling Systems automation system also integrated process control with the company network using Sterling’s WebCentral™ application software.
Sterling Systems built all electrical and control panels, did system engineering of all components, custom application engineering and also implemented its WebCentral™ software. WebCentral is a browser-based application that allows you to access the database of the Sterling Systems control system. You can review and print historical reports and change system parameters from a remote PC, so long as the PC resides on the same network as Sterling Systems automation control system. Because WebCentral is browser-based, it is very simple and intuitive to use. It is ideal for applications where a variety of individuals need to access information from the control system in a secure, reliable and simple manner. In this application of WebCentral, the user could remotely view reactor data in graph form, change system parameters, and search for, view and print historical data.
Features of Process Control Automation System for Recycling Tires
- PLC/Motor Starter enclosure is included to house the PLC, motor starters, Honeywell burner controllers, thermocouple receivers, associated I/O, 480vac main breaker disconnect, and 15” AB Panel View +6 touch screen display.
- A console is included that will have two 17” touch screen monitors operated by a single PC. The PC will have the necessary software loaded to run the HMI program, SQL Express database server, and WebCentral supervisory control.
- Monitor and control temperature, pressure, oxygen and burner control of each reactor.
- Monitor fluid level in heavy and light oil tanks.
- Monitor pressure in reclaim gas tanks.
- Process control of Reactor temperatures, cycle, purge and other process times, and safety lockouts.
- Alarm monitoring and handling.
- Reactor shutdown control.
- WebCentral supervisory control included.
Clicking on any piece of process equipment in the reactor graphic will display a Manual/Off/Auto equipment control screen for the equipment selected. When in the Manual mode the equipment output will be immediately energized/turned-on/activated. Any piece of equipment running in the Manual mode is not interlocked with other pieces of equipment. That means the equipment will remain energized or turned-on until the item is taken out of the Manual mode of operation.
When in the Automatic mode the equipment will perform as designed and called for by the automatic control system. In normal operating conditions all equipment will be in the Automatic mode. For some pieces of equipment, such as the reactor motor, there will also be required a speed reference in order to operate. For this type of equipment, there will be two additional items, a manual speed reference, and a speed lock button.
Starting/stopping a batch
The batching process for recycling tires is controlled from reactor console. Pressing the Start pushbutton will illuminate its green light and the first cycle in the process will begin. Pressing the stop button will advance the process to the next cycle immediately. Aborting a batching cycle can only be done in the Admin security level and Equipment Status screen.
WebCentral Supervisory Control App
The Control Room Computers were provided preloaded with WebCentral software. This provides access to reports and information stored in the SQL Server Express database to any PC or mobile device with a modern web browser that is on the same internal network as the Control Room Computer. Users who have been granted security access to WebCentral can log in with a web browser and view information such as trending reports, system set points, and system status. Security can be configured to allow or deny access to reports and system set points.