CHALLENGE ADDRESSED

Sellafield Ltd aims to reduce the lifetime cost of higher activity waste containers by 50 per cent, while introducing an improved range of containers for transport and long-term storage.

Tens of thousands of such containers will be needed for decades to come, so cutting costs will save billions of pounds while providing long-term opportunities for innovative companies.

TECHNOLOGY BACKGROUND

Heatric have over 25 years experience in diffusion bonding stainless steels. It plays a key part of the manufacture of our heat exchangers which are used in the Oil & Gas, Chemical Processing and Petrochemical Industries.

Heatric believe they can apply this technology to deliver a solution to the Sellafield 3M3 cost down strategic objective.

Heatric have been diffusion bonding Printed Circuit Heat Exchangers for over 25 years. The diffusion bonding process is an ASME approved solid state joining process. Diffusion bonding the container flanges offers real cost and lead time reductions from the current process.

Heatric can supply diffusion bonded flanges to all approved container manufacturers and also have the required capabilities to fabricate the complete container. The diffusion bonding process would offer a more repeatable and stable process than other potential options like casting.

THE CURRENT PROBLEM

The current method of manufacture using the 60mm plate profile wastes almost 70% of the raw material due to the profile geometry.

The profile requires significant first stage machining which causes material stability issues due to inherent residual stress being released with the volume of material removed.

NAMRC have conducted trials to near shape cast this product with limited success to date.

THE PROPOSED SOLUTION

Using the Heatric diffusion bonding process to generate a near shape profile for the top flange will significantly reduce base material and machining costs.

Heat treatment applied during the diffusion bonding will eliminate the residual stress that is often found in duplex thick plate sections. Our initial estimate offers a minimum cost reduction of 30% of the manufacture of the top flange.

DIFFUSION BONDING TECHNOLOGY

Diffusion bonding is a solid state joining process first developed for commercial use in heat exchangers by Heatric in the early 1980’s. Diffusion bonding allows for the creation of compact heat exchangers with exceptionally high performance.

This process involves the bonding of flow plates in a heat exchanger ‘stack’ using a high temperature, high pressure process with no melting or deformation of channels. The size and shape of the flow paths is maintained, ensuring flow integrity and complete bonding of all plates throughout the stack.

The interfacial area between two metal flow plates becomes welded together as atoms intertwine with one another and this allows for the incredibly precise construction of the internal flow passages within the block.

No brazing flux or filler is used in the diffusion bonding manufacturing process which is a contributing factor to the high-integrity, high-strength, and exceptional heat transfer performance of Heatric’s diffusion bonded heat exchangers.

The solid, diffusion bonded block can then be subtractively engineered to match the client’s exact size and weight requirements, providing them with a highly effective, bespoke heat exchanger.

THE BENEFITS OF DIFFUSION BONDING

This innovative manufacturing process allows for substantial improvements in the way a heat exchanger operates:

  • Massive reductions in size – up to 85% smaller than conventional exchangers
  • Extreme high pressure capabilities – Heatric PCHEs are able to withstand pressures over 900 bar (equivalent to 13,000 psi)
  • Operating temperatures ranging between deep cryogenic to over 900°C/1,600°F.
  • High structural integrity due to the solid state construction method employed

ORGANISATION

Heatric
Holton Heath
Poole
Dorset BH16 6LT

Telephone. +44 (0) 1202 627000

Email: htrc-info@meggitt.com 

www.heatric.com

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