Thermal Insulation System Repair and Maintenance

Restoring Safety and Performance at a Biomass Power Plant

At Powertherm, we pride ourselves on delivering industrial thermal insulation systems that not only perform efficiently but also meet the highest safety standards. Our site teams were mobilised to a biomass power plant to undertake a critical repair and maintenance project that highlighted just how vital correct thermal insulation system design, specification and installation are.

 

 

Identifying the Problem – Site Inspection

We were initially approached by the client to carry out a full inspection of the thermal insulation system installed on the boiler and associated equipment and process ducting. 

During the initial visual inspection, our experts quickly identified a serious issue: the existing insulation system, installed by a previous contractor, was not fit for purpose. 

Excessive heat from the boiler was transferring onto the external cladding, resulting in clear scorching on the surface. This not only indicated poor thermal performance but also posed a significant safety risk. 

Following the on-site inspection our engineers detailed findings and recommendations to fix any issues back to the client. 

 

 

 

Understanding the Root Cause 

Upon closer examination, two key issues were identified: 

• Insufficient insulation thickness, preventing the system from achieving the required thermal performance 

Insufficient insulation thickness can significantly reduce thermal efficiency, allowing heat to escape. Given the boilers high operating temperature, this leads to increased energy consumption and high operational costs, due to inefficiencies. 

 

 

• Incorrect cladding specification and installation, with Plastisol cladding fixed directly onto boiler stiffeners, allowing heat transfer to the outer surface  

For this application, health and safety requirements needed the external surface temperature of the cladding to be at a maximum of 50°C. However, with the boiler operating at temperatures exceeding 300°C, the existing system fell dangerously short of compliance. This created a high-risk environment, with the potential for serious injury to personnel working near the equipment.

 

Powertherm’s Solution 

Following our assessment and consultations with the client, Powertherm were awarded the works to design and implement a fully engineered thermal insulation system and associated access solutions to rectify the issues and restore safe and efficient operations. 

 

Scaffolding Access 

To facilitate safe access across all working areas, our scaffolding team provided a complete scaffolding solution in tight spaces.

 

 

 

Before insulation works could begin, the team erected various intricate independent scaffold structures and edge protection using tube and fitting scaffolding. All scaffolds were constructed in accordance with TG20:21 (NASC Technical Guidance) and SG4 (Preventing Falls in Scaffolding Operations) regulations. In addition, scaffolds were regularly inspected to ensure full compliance with safety standards and were safely dismantled upon project completion. 

 

Thermal Insulation System 

Before we stepped foot on-site our design team were called upon to design and specify a thermal insulation system that was fit-for-purpose. The technical team gathered all relevant information like operating temperatures, equipment geometry and environmental factors before running calculations to enable them to specify the right insulation solution. 

Then it was over to Powertherm’s TICA certified insulators to remove the existing spent insulation system before installing our robust, high-performance thermal insulation system designed to meet both thermal and safety requirements.

 

 

Substructure 

To allow for the required insulation thickness, we needed to install a substructure which provided the necessary gap between the boiler wall and the outer cladding. Our design team specified the DUK Rail System: the system consists of anchors, which are cut to length and welded to the underlying equipment. Rails are then attached, which provide a fixing point for the external protective cladding. Insulation pins were also installed to help secure the insulation material and prevent potential sagging. 

• DUK Rail System  

• Welded Ø5mm insulation pins  

 

Insulation 

Our design team calculated that to achieve the required thermal performance of the insulation system and safe touch temperatures, a multi-layer thermal insulation system was required.  

• 140mm thick mineral wool: 

• • Layer 1 – Slab 

• • Layer 2 – Wired mattress 

 

 

Cladding 

Prefabricated protective cladding was cut and formed to shape to the required design specifications of each item of equipment at our in-house fabrication facility. 

• 0.8mm Aluzinc profile and flat cladding

 

 

Flexible Insulation Jackets 

Our flexible insulation division designed and manufactured specialised insulation jackets made to measure to fit associated valves, flanges and pipework. These jackets were secured with Velcro fastens and drawstrings enabling simple installation and removal to provide easy access for repair and maintenance, whilst delivering thermal performance.  

• Grey silicone-coated glass cloth outer layer  

• Mineral wool insulation 

• Velcro and drawstring fasteners 

 

 

This upgraded system ensured that external surface temperatures were brought within safe limits, eliminating the risk of heat transfer and surface scorching. It also stopped unnecessary energy waste and carbon emissions through a significant reduction in heat losses – reducing costs and improving operations. 

 

The Result 

With the new thermal insulation system in place, the boiler and associated equipment and ducting were fully restored to safe and efficient operating conditions. The improved specification not only enhanced thermal performance but also ensured compliance with industry safety standards, protecting both personnel and plant assets. 

 

 

Project Overview 

• Industry: Power Generation 

• Plant Type: Biomass 

• Contract Type: Repair & Maintenance  

• Services Delivered:  

• • Industrial Insulation  

• • Flexible Insulation Products  

• • Scaffolding Access  

 

Delivering Confidence Through Expertise 

This project is a clear example of how improper thermal insulation system design and installation can lead to serious operational and safety risks. At Powertherm, our expertise ensures that every system we install is engineered to perform safely, efficiently, and in full compliance with regulations. 

If you’re concerned about the performance or safety of your current insulation systems, our team is ready to help.

Check out our industrial thermal insulation services here >>