Mannings Improve Efficiency At Refinery

The successful completion of a challenging project by Mannings Thermal & Environmental Engineers Limited of Southport, England has produced energy savings on a furnace, which is over 60 years old.

The savings were made by improvements in efficiency of a direct fired crude oil heater which is part of a vital process at an Oil Refinery in southern Poland. After visiting the site to carry out a detailed survey of the plant, Mannings were confident that they could achieve the 10% fuel saving required by installing their latest combustion equipment and control systems.

The refinery furnace was originally built as a coal fired unit but had been modified to run on natural gas as well as on ‘wild gas’ which is a high energy by-product formed during fractionation of crude oil. The purpose of the heater is to raise the temperature of the crude to 370 degrees centigrade so that it is suitable for use in the refinery. Some of the heat from the furnace is also used to superheat steam in an economiser.

The re-design, which Mannings came up with, involved replacing four existing manually controlled burners with their own high velocity gas burners which had to be specially adapted for the application. The burners were set up in the factory and tested by Mannings technicians to ensure that there would be no delays on site. Les Oliver who is Manager of Industrial Heating at Mannings said “the combustion aspect of this project had to be carefully designed and the whole operation had to be planned in minute detail since it was only possible to carry out the site work during the two week annual shutdown at the refinery”. All of the equipment required for the modification was shipped to site in a single 40 foot container and Mannings engineers were able to complete the project within the required timescale.

In addition Mannings also supplied new combustion air fans to match the burner system and installed gas trains with fuel/air ratio controls. The furnace temperature and the oil outflow temperatures were monitored and controlled and final adjustments were made during the commissioning phase to optimise performance. The whole system is controlled from a locally mounted panel and this is linked to the refinery control system.

The moment of truth came when the final tests were carried out to determine the exact fuel savings achieved in practice. The refinery were pleased to report that the efficiency improvements were much better than they hoped and that Mannings have been able to achieve an 18% improvement which is also much higher than the contractual requirements.