Export Grain Terminal Control System Upgrade

Location

Vancouver, British Columbia

Customer

Alberta Wheat Pool (now Cascadia Terminal)

Background

The Alberta Wheat Pool export grain terminal in Vancouver, now Cascadia Terminal, is a transfer point for Canadian grain. Here, grain from the Canadian prairies is unloaded from railcars, weighed, cleaned and classified, and then stored. At the appropriate time, the stored grain is retrieved, weighed, and loaded onto ocean freighters for export.

The terminal was built in 1928 and expanded over the years to where it presently handles 4 million tonnes of grain per year and has a storage capacity of 285,000 tonnes.

Since grain dust is explosive, many areas of the terminal are classified as hazardous areas and all material handling equipment, such as conveyors, vertical elevating legs, and drag conveyors, are interlocked to dust collection systems and conveyor monitoring devices to minimize fire and explosions from grain dust. The control system interlocking is elaborate and there is a much higher number of field devices and interlocking points for each piece of equipment. The final control system for the terminal is expected to have about 8,000 input/output points.

Reason for the Project

The volume of grain flowing through the port of Vancouver is increasing steadily and there is a demand by the grain export terminals for more capacity. After studying the situation, Alberta Wheat Pool concluded that the most effective way to modernize their existing terminals is by implementing various facilities upgrades as well as a complete upgrade of their plant control sys-tem. This new control system will also allow them to implement supervisory computer controls, where the supervisory computer can automatically select conveyor routes, storage bins, and cleaning equipment.

The new control system will perform all the system interlocking and control previously done by hard-wired relays as well as provide a better operator interface with CRT based colour graphics displays.

Project Scope

The complete control system in the terminal is upgraded from the motor control centres to the field devices and operator interfaces. Universal Dynamics engineers and technologists performed a field audit of the system to confirm all wiring prior to design and planning for the upgrade work. Working around Alberta Wheat Pool's production schedules, individual motor control centres were changed over to a new control centre and the new control system. A new room was used for all the new motor control centres and the old motor control centres were used as a wiring junction point with existing wiring to motors and field devices. New video graphics based operator termi-nals were used side by side with existing conventional pushbutton and pilot light panels until the complete system were transferred over in a period of fifteen months.

The completed system includes a new control building connected to the terminal through control system network cables. There are a total of six video graphics operator displays and control is done by track-ball point and select. Universal Dynamics configured the graphics displays as well as the custom display tasks to customize some of the display features to Alberta Wheat Pool's specific requirements. These custom tasks allow better display of system status, provide faster system response time, and organize the data format so it can communicate easily with a supervisory computer in the future.

Benefits of Project

Plant information is now easily accessible by operation and plant management personnel.

Flexibility of the plant is greatly enhanced due to better understanding of plant conditions by operator and management alike. Re-configuring the plant to handle different products is much easier than before.

Troubleshooting of the system is much easier with the diagnostic capability of modern day programmable control systems.

Operators find it much easier to set up product transfer routings with sequenced starts and stops for conveyors and equipment for the routes.

Throughput and system availability are both noticeably improved.