Furnace Improvements Services - A rewarding opportunity and beyond

We were recently requested to look into the problems a refinery was having with their brand new Crude and Vacuum heaters. These heaters were not reaching the design capacity. We made a field visit to the site. Our quick analysis found the heater design was deficient on several fronts. It would have been very easy to fix the design on paper. Once heaters are built, the fixes are very expensive and require shutdown.

In most cases, heater design is based solely on computer simulations. Heater design involves much more than running computer simulations. There are several things that a computer simulation cannot take into account. You need practical experience to design fired heaters.

One of the major development that has taken place in the last 20 years is the installation of Low NOx burners in heaters. The low NOx burners have changed the combustion characteristics in fired heaters. They produce flames that are hotter on the top and cooler on the bottom. Their flame lengths are almost double that of the old burners. Neither of these factors are taking into consideration during a computer simulation of fired heaters. No heater vendor makes a correction in the heater design calculations for low NOx burners. As a result, the heaters run short on the capacity. FIS has developed design algorithms that are used during fired heater design with Low NOx burners. FIS already has several heaters working successfully with Low NOx burners. Another issue which has been largely over looked by heaters vendors is the location and number of burners in the heaters.

Most of large heaters are fitted with air preheating systems. Calculation of the correct system pressure drop is very important. It is not provided in the simulation. Most engineers in the office, without field experience, do not understand the system losses and the calculations required to be done. Recently we saw an installation with a 90° bend at the fan discharge. To make matters worse, they even put turning vanes in the bend. When the duct layout and fans are not correctly sized, they cause a lot of problems.

Excellent heater design should always be your starting point. Any heater vendor can supply burners, steel and refractory materials, but can they supply a heater with excellent performance? It is important that heaters perform with high efficiency and long run lengths at full capacity.

Contact us before you decide to buy or build a heater for your next project. It is our guarantee that you will be fully satisfied with our design. We will make sure your heater reaches at least 100% of the design capacity and may be even beyond that. Our bottom-line is to make you a ‘star’ at the end of the project. We do not want you to be chasing heater vendors after the heater is started up.