Project Case Study
Bespoke Liquid-Liquid Separators Designed and Manufactured in Scotland
Successful Project Delivery
Complaince:
Built to meet demanding project specifications, engineering requirements and quality standards, with full traceability from material procurement through final inspection.
Certification
Complete quality documentation, including material certificates, inspection records, test reports and Certificate of Conformity, supplied with the equipment.
Corrosive Operating Conditions
Designed for challenging nitric-acid and organic service, with corrosion-resistant stainless-steel construction and controlled surface treatment after fabrication.
Completed Kapwell liquid-liquid separator during final testing at our Scotland manufacturing facility prior to delivery.
Overview
Kapwell Ltd successfully completed the design, engineering, manufacture, testing and delivery of two bespoke liquid-liquid separators for a specialist solvent extraction application.
The project comprised:
- 1 × Light Phase Liquid Separator
- 1 × Heavy Phase Liquid Separator
Both units were designed to provide polishing separation between immiscible organic and aqueous phases, with each separator primarily handling one continuous phase while removing a small residual quantity of the other.
The equipment was designed and manufactured in Scotland and successfully delivered within the agreed programme and budget.
Key Challenges
The client required two compact separators for a specialist process involving organic solvent and aqueous nitric-acid phases.
Although relatively small in capacity, the application required careful consideration of:
- Separation of two immiscible liquid phases
- Low interfacial tension
- Material compatibility with the process fluids
- Sufficient liquid residence time for effective phase disengagement
- Operation close to atmospheric pressure
- Compact equipment suitable for integration into the client’s process system
- Appropriate manufacturing quality, material traceability and testing
The Light Phase Separator was required to handle predominantly organic liquid containing a small residual aqueous phase, while the Heavy Phase Separator handled predominantly aqueous liquid containing residual organic phase.
Design
Basis
Kapwell developed the separator design around the client’s process data and operating requirements.
Parameter | Design Basis |
Normal total flow | Confidential Data |
Maximum upset flow | Confidential Data |
Operating pressure | Confidential Data |
Design pressure | Confidential Data |
Operating temperature | Confidential Data |
Minimum residence time | 15 minutes |
Aqueous phase density | Up to approximately 1,260 kg/m³ |
Organic phase density | Approximately 810–860 kg/m³ |
Interfacial tension | Approximately 0.01–0.02 N/m |
The minimum 15-minute residence time provided the necessary volume for effective gravity separation of the two liquid phases under the specified operating conditions. 22004797 Rev 02 EnQ15555 Commer…
Solution
Kapwell engineered two dedicated separator vessels rather than applying a generic standard design.
The supplied equipment incorporated:
- Stainless-steel vessel construction
- Purpose-designed internal separation arrangement
- PTFE/PP internal components where applicable
- Process inlet and outlet connections
- Vent connection
- Drain connections
- Instrument nozzles
- Spare and spray-ball connections
- Vessel support arrangement
- Identification/nameplate
- Pickling and passivation following fabrication
- Material and test documentation
The original supply specification identified stainless-steel vessels complete with internals, supports, process nozzles, instrument connections, drains, tag plates, surface treatment, testing and project documentation.
Materials Selection
Material selection was particularly important because of the presence of the aqueous nitric-acid phase.
Kapwell selected 304L stainless steel for wetted components, subject to final confirmation of the process chemistry, with 316L available where additional contaminants or corrosion considerations required it.
Following fabrication, the stainless-steel vessels were pickled and passivated to restore the corrosion-resistant surface condition following welding and fabrication activities.
Engineering and Manufactur-ing in Scotland
The project was engineered from Kapwell’s Aberdeen office and manufactured through Kapwell’s Scottish manufacturing operation in Gourdon, Aberdeenshire.
Kapwell managed the complete equipment lifecycle, including:
Process Engineering → Mechanical Design → Detailed Drawings → Material Procurement → Fabrication → Inspection → Testing → Documentation → Delivery
This integrated approach enabled Kapwell to maintain close control of design interfaces, fabrication quality and delivery throughout the project.
Inspection and Testing
Quality assurance was incorporated throughout the manufacturing process.
The project included:
- Qualified welding procedures and personnel
- Material traceability
- Dimensional inspection
- Visual inspection
- Appropriate weld examination
- Pressure/leak testing
- Final equipment inspection
- Material certification
- Test documentation
- Certificate of Conformity
Kapwell’s proposed quality approach specifically included dimensional and visual inspections, appropriate NDT where required, pressure or leak testing and EN 10204 material certification for applicable wetted components.
Project Outcome
The project was successfully completed with the equipment:
- Designed in Scotland
- Engineered specifically for the client’s process conditions
- Manufactured in Scotland
- Inspected and tested before dispatch
- Delivered within the agreed programme
- Completed within the agreed project budget
The completed units demonstrate Kapwell’s ability to provide engineered separation equipment not only for large industrial process packages, but also for specialist, pilot-scale and relatively low-flow applications where process performance and materials compatibility remain critical.
Kapwell Capability
Kapwell provides bespoke separation equipment for applications including:
- Liquid-liquid separation
- Gas-liquid separation
- Oil-water separation
- Mist elimination
- Scrubbers
- Knock-out vessels
- Process separators
- Degassers
- Desanders and hydrocyclones
- Specialist laboratory and pilot-scale separation equipment
Our scope can extend from initial process evaluation and equipment sizing through to detailed engineering, manufacturing, inspection, testing, documentation and delivery.
Need a Bespoke Separation Solution?
If your process requires separation equipment designed around specific operating conditions, fluid properties, materials or installation constraints, Kapwell can support the project from concept through to delivery.
Kapwell Ltd
37 Waterloo Quay
Aberdeen, Scotland, UK
Email: info@kapwell.co.uk
Tel: +44 (0)1224 007 288
Website: www.kapwell.co.uk