Implementation of new automation systems and BFDs for the Coke oven at Zaporizhkoks

In 2020, Zaporozhkoks launched a large-scale investment program to improve energy efficiency by modernizing production. One of the program’s stages was the introduction of new automation systems and high-voltage frequency converters (hereinafter referred to as HVFCs) for gas blowers in the capture shop and the smoke exhauster in the boiler and turbine shop. At the same time, the old relay automation and process control system should remain in hot standby to improve the uninterrupted operation of the modernization facility.

Control system for the blower fan of the recovery shop (RS)

The scheme provides for frequency control of one of the four GDMs at the choice of the operator-technologist. The technological scheme provides for automatic control and stabilization of coke oven gas discharge by one of the two groups of coconut batteries. The automatic control system is based on a cabinet of process and relay automation with a Siemens programmable logic controller (PLC) that controls the HPL. A PC-based automated workstation (AWS) was built for remote control, visualization and event recording.

Depending on the productivity and cyclicality of the coke oven batteries, the recovery shop provides for the operation of more than one DGM from different groups of batteries. For example, one BFG operates from HPV for one group of coke oven batteries, and another BFG operates from the mains, but with a throttle valve. All gas blowers operate on one of the two injection manifolds.

The automatic frequency control system is integrated into the existing automation in such a way as to keep the existing “old” automation in hot standby.

Given the existing process load of the coke gas recovery shop and coke oven gas productivity, the GDMs are loaded at 75-85% of their rated capacity. The economic effect of the frequency drive is up to 13%.

Control system for the smoke exhauster of the boiler and turbine shop

The smoke exhauster speed control system is operated manually from the BFG operator’s panel located in the BFI room of the BCC operator. The existing smoke exhauster gate control scheme remains in operation, but in manual mode when the gate is fully open.

The existing automation of the CPC is based on relay automation using programmable logic controllers from Honeywell (USA). The operator controls the gates, gas supply valves and other mechanisms remotely from an automated workstation (AWS).

Chimneys and draft machines of the KTC are used to regulate the boiler draft, they are part of the performance control circuit and optimize gas combustion.

The existing control system provides for the regulation of the smoke exhauster’s performance through inefficient throttling with a gate. And if in the winter season the performance of the smoke exhauster was in the nominal mode, then in the summer season it is necessary to reduce the performance.

The estimated energy savings compared to the old control system of Zaporizhkoks PJSC are up to 30%. According to the company’s specialists, the estimated economic effect of the frequency converters implementation in 2020 is more than UAH 2 million.

Project manager: Viktor Golovin.