Corrosion of the heater radiant section steel casing can result in damages and/or decrease in strength, so that the complete steel construction cannot be guaranteed anymore. Corrosion of the steel casing of furnaces is a common problem and, traditionally, clients/end-users mostly opt for a complete replacement of the furnace. However, nowadays, clients often opt for a complete in situ refurbishment of their furnaces.
The disadvantage of such an in situ refurbishment is that the turnaround period can take at least a few weeks, and up to months, so that the choice for a replacement is still being reconsidered.
Based on this demand, Calderys has developed a complete turnkey concept for the refurbishment of furnaces, together with sub-vendors, as valuable partners to supply the full scope of refractory lining and mechanical work. The company plans the refurbishment in such a way that the on-site activities are limited to removing and assembling the new radiant panels and only replacing the refractory lining of the steel columns in situ on site, which seriously decreases the lead time.
The full turnkey turnaround of such a refurbishment project consists of: safety management; 3D scanning; detailed engineering; site mobilisation; on-site cutting of the existing steel casing; refractory demolish; work shop steel panel fabrication; anchor welding; steel coating; shop lining of the steel panels; purchasing; logistics; refractory installation; quality assurance and quality control; shop and site supervision; and project management.
During the whole project safety regulations have to be re-considered for the following project scope and services:
Calderys starts with scanning the entire steel and refractory structure to determine the basis.
With the full 3D scan of the existing steel structure and refractory lining of the equipment to be refurbished, the detailed engineering is being prepared, up to the smallest steel and refractory details. Before the start of the project in a pre-engineering stage, the sequence of replacement of all steel casing is defined. After 3D scanning and detailed engineering, the exact measurements and details of the panels are determined.
To guarantee the strength of the heater construction through the complete process, Calderys prepares and provides steel strength calculations of the actual situation, during demolition, built up and final stages. Every situation is worked out into detailed and if necessary temporary or permanent reinforcements are placed.
Product development and engineering
For these type of projects, Calderys uses a specific development of 3D scanning the entire existing heater. Material selection is primarily based on the existing refractory with some improvements where requested by the customer. The refractory design is always based on heat transfer calculations with the given parameters.
Demolition of the refractory lining is done exactly in according with the local and client’s regulations. When full steel panels are being removed, refractory lining will be removed at a customer’s yard or in a workshop. From the steel sections which are not replaced, the refractory will be demolished in situ on site.
Manufacturing, purchasing, supply and logistics
The material scope of supply consisted of insulating castable, anchors, ceramic fibres, steel casing and steel coating.
Before release for shipment, the production and final inspection certificates of the finished goods are strictly monitored as per the inspection plan. In close collaboration with qualified logistic partners, Calderys arranges for the goods to be picked up from a warehouse where all materials have been gathered for the project and to be delivered to the customer’s site.
Site management, quality control, safety and refractory site installation
The installation involves three different works, namely steel casing production at a mechanical sub-contractor; pre-lining and dry-out of the steel panels in the workshop and on-site panels and refractory installation.
All of the above activities will be executed in cooperation with the shop and site safety officers, as well as a construction team, to ensure that all refractory activities would be carried out at the highest possible safety level. Furthermore, safeguarding measures will be taken against any possible interference from ongoing construction activities from other contractors on that same site.
The entire project, from start of detail engineering until completion and dry-out, is always a challenge. Calderys helps to execute these kinds of projects extremely accurately and timely, in accordance with the above scope, within a shortest possible schedule and, most importantly, in the safest manner.
Read the article online at: https://www.hydrocarbonengineering.com/refining/29052018/furnace-refurbishment-decreasing-downtime-safely-and-efficiently/