How to Prepare for Maintenance Outage Season: Energy-from-Waste Edition

An energy-from-waste plant processes around 15-17 million tonnes of waste every year, turning it into electricity, heat, and other usable resources for millions of households and businesses across the UK. The sole purpose of these plants is to reduce the amount of landfill use, supporting the country working towards a more sustainable future.

What is a maintenance outage?

A maintenance outage is when an energy-from-waste plant is taken off line for a specific period of time to perform works such as inspections on critical equipment, routine maintenance and repair, and deep cleaning. They are meticulously planned, and it is absolutely critical that the work is delivered safely, and productivity during the outage is maintained at a high level.

Some of the common activities carried out during a maintenance outage at an energy from waste plant include:

Refectory Lining: This is one of the biggest drivers to have an outage. Works include inspections, patching or re-lining, and slag control.

Grate Works: As a crucial component in the energy recovery process, it's essential this is properly inspected, cleaned, repaired, and maintained during an outage.

Superheaters: Replacement or weld overlay processes to the superheater tubes.

Steam Turbine Generator: Responsible for converting the heat produced from burning waste and turning it into electricity, during an outage the steam turbine generator may require re-blading, rotors balancing, and sometimes overhauling the main stop/control valves.

Control Systems: Updating current software, and replacing any failed equipment.

Boiler: Cleaning, inspection & hot works processes.

How to prepare for a maintenance outage

Preparation is key to a successful outage. Here are the top ways to prepare:

• Ensure you have a set schedule for when this will be carried out, with clear deadlines to meet. This allows you to plan what activities need to be done and when, and to take into account any downtime required.
• Have a defined scope of works, so you know what activities are being done and if you need to hire any extra equipment to support. This also helps with checking how many contractors you need to bring in.
• Have a communication plan, decide how you are going to communicate with staff within the plant, as well as stakeholders, and customers if needed. Identify the best channels to do this on- notice boards, internal systems, social media etc.
• Check access routes and escape routes so you are prepared if an emergency breaks out.
• Ensure all contractors are inducted to site before the outage begins and understand the procedures and guidelines whilst on site.
• Prepare toolbox talks for morning huddles- RVT Group offers ready-made toolbox talk videos covering a wide range of topics, all inline with HSE guidance.

How engineering controls can support an outage

Engineering controls remove hazards at source before it comes into contact with a worker. Within the hierarchy of controls, it's considered a very effective way to control hazards if used correctly and set up to perform efficiently. The hierarchy of controls can be seen below:

Important to note: The hierarchy of controls helps us approach hazards in a structured way, starting with the most effective measures to the least effective. It's common for us to hear that companies are using PPE against hazards such as dust, however, this is considered the least effective way to protect workers from hazards. Personal protective equipment needs to be specified, fitted and maintained correctly, and even then, there is still no guarantee it will be 100% effective. PPE's biggest flaw is that it only protects the person wearing it, and not other people nearby who might be exposed.

When carrying out a maintenance outage, the activities are vital, meaning elimination or substitution are not an option, and engineering controls are the best approach. When looking at engineering controls, it is important to understand that one size does not fit all. Every project is different and ensuring the solution is suitable for the environment and the application ensures workers are safe, without compromise.

You need to carefully identify the hazard and assess the risks before you select a suitable control method. The word ‘method’ is important, because it’s not just about selecting the right unit - the installation and set up are equally as important. You need a solution that will ‘Capture’, ‘Contain’ and ‘Control’ the hazard. RVT Group calls this the 3C’s® Methodology:

1. 'Capture' the hazard as close to the source as possible.
2. 'Contain' the hazard and ensure it cannot escape or spread to other areas.
3. 'Control' the hazard, implement any further controls that may be necessary.

If all three elements are taken into consideration, you can achieve an effective health hazard control solution that protects your people, the surrounding environment and your outage timeline, avoiding any unnecessary downtime.

RVT Group's engineering controls

RVT Group have been supporting the energy-from-waste sector for several years, providing effective engineering controls that extract hazards from the source. We provide modular solutions that means we can tailor to your exact requirements and project.  We understand the importance of improving productivity, and are passionate about supporting our clients achieve high levels of quality workmanship and productivity.

Common challenges we support with this include:

• Fume control

If hot works are being carried out, we can eliminate fume build up caused by burning, cutting, welding and grinding operations. Our solutions for fume control include local exhaust ventilation (LEV) systems, and static and mobile welding fume extraction units.  High pressure extraction equipment allows us to use small diameter flexible hoses, which can run significant distances.  This helps to minimise the risk of blocking manway accesses.  The use of articulated arms and magnetic capture hoods ensure the fumes are captured as close to source as possible.

Without effective fume control, workers can be exposed to hazardous fumes and if breathed in, can lead to serious health effects. Repeated exposure to welding fume for example can lead to arc-eye, irritation of the throat and lungs, asthma, and cancer.

• Dust extraction

Dust is a common hazard encountered during an outage, and there are various ways to control it. RVT Group's solutions focus on extracting from the source, preventing it from reaching the atmosphere and spreading to other areas. Without effective control of dust, it can accumulate and spread to other areas putting others at risk and create a hazardous environment for workers to be in.

Silica dust, a common dust workers on an outage will be exposed to can lead to a serious health condition called silicosis. Silicosis is caused when we breath in the small particles from silica dust, they will get lodged deep in our lungs which over time causes inflammation and scarring. These tiny jagged particles also reduce the lung's ability to take in oxygen, making it a debilitating and fatal disease.

• Ventilation

Forcing a fresh air supply into a confined space prevents any hazardous build-up of gases and other contaminants such as dust and fume. Without ventilation, harmful contaminants can have an adverse effect on workers immediate, and long-term health.

Our ventilation range includes high pressure centrifugal and axial fans suitable for a wide range of projects and spaces. Should your maintenance outage be carried out in potentially explosive environment, some of our fans come ATEX rated, giving you peace of mind your solution is safe, and effective.

RVT Group appreciates that carrying out an outage is demanding, so our engineering controls focus on keeping productivity high and risk low. With the effective control of hazards, you are left to focus on delivering a successful outage.