Supporting Simpsons Malt with renewable energy solutions

The team at Turnbull & Scott received an enquiry from Simpsons Malt, a renowned supplier of high-quality malts who they have long supported, and for whom they have become a Trusted ™ supplier. Simpsons Malt shared their ambitious plans to meet their sustainability goals, ultimately achieving carbon neutrality by 2030 across their malting sites.

Their plans involved commissioning a low-carbon Energy Centre at the Tweed Valley Maltings site in Berwick. This setup aims to save 25,000 tonnes of carbon annually, translating to an approximate 80% reduction in carbon emissions at the UK’s largest malting site.

Traditionally in the UK, malt is dried in kilns fed with a hot air stream. The air is heated to the required temperatures using a series of gas-fired burners. This plan includes the implementation of a pioneering 12MW electric boiler powered by ‘curtailed’ wind energy alongside three 6MW biomass boilers, utilising locally sourced, low-grade woodchip to replace the gas consumption of the burners.

Groundbreaking initiative

In this groundbreaking initiative, the high-voltage electric boilers would be powered by wind energy, which traditionally would have been switched off during excess wind generation, addressing the issue of renewable energy wastage in the UK’s energy grid. The challenge for Turnbull & Scott is to help Simpsons Malt redesign the air intake stream to allow 80% of the heat required to be delivered in the form of low-pressure hot water from the Energy Centre, rather than the traditional gas burners.

The solution

The team quickly mobilised to assist Simpsons in developing an innovative malt drying solution that fitted with their plan to electrify the industrial air heating process and harness renewable wind energy efficiently. A specialist design team at the company’s Edinburgh Design Hub undertook thermal modelling to determine the size and geometry of the heat exchangers which would be required for the upgraded malting kilns.

A plan was developed to use custom-designed LPHW heating coils for the malting kilns, which would be crucial in enhancing the traditional kilning stage of the malting process. A concern expressed by the client was that any alteration to the airflow could impact on the drying process of the product. It was therefore vital that the Turnbull & Scott team understood the impact of the heat exchangers on the air-side pressure drop.

Working collaboratively with the client, project funders, and EPC’s design teams, the team reviewed CFD analysis on airflow and pressure drops to hone the heat exchanger geometry to optimise airflow and thermal performance.

To guarantee the performance of the heat exchangers, a wind tunnel was constructed, and prototype heat exchangers were produced to test and validate the pressure drop performances.

Unique plate-fin coils

Renowned for designing and manufacturing highly durable industrial coils, the Turnbull & Scott solution is to supply unique plate-fin coils with steel-encased tube header design, incorporating the taper ferrule joint.

The company will deliver 30 custom-designed LPHW plate-fin air heating coils for the malting kilns. These coils aim to ensure integrity at high temperatures and pressures, overcoming the challenge of traditional return bends which are known for their fragility. The products will be delivered to the site for the customers by May 2024, contributing significantly to the project’s goal of blending traditional and modern technology to reduce carbon emissions substantially.

Achieving carbon-neutral goals

“This collaboration with Turnbull & Scott marks a significant stride towards our carbon-neutral goal, blending cutting-edge technology with time-honoured traditions,” stated Steven Rowley, Operations Director, Simpsons Malt Limited.

“Our partnership is a testament to the power of innovation, and we’re optimistic about embarking on more sustainable journeys together.”