Foundry operations boosted by SEKO pump upgrade

A large-scale manufacturer of resin sand mixers, facing concerns over the efficiency and environmental impact of its equipment, turned to global dosing pump specialist SEKO for a multi-purpose solution.

Within the foundry industry, resin-coated sand has for many years been a popular material for iron casting moulds as it is easily compacted and provides a smooth, consistent and defect-free surface to the finished product. Resin sand is considered among the best moulding sands for the casting of steel, cast iron and non-ferrous metals, including automotive parts such as pumps, motors and engine blocks.

Resin moulding sand is produced by dosing one or more binder chemicals – including furan resin – into crude sand before mixing and pouring the material into casts to harden, ready for the product pattern to be imprinted.

benzene, toluene,

and xylenes

benzene, toluene,

and xylenes

A major drawback of this process is that when furan resin is thermally decomposed during metal casting, air pollutants such as benzene, toluene and xylenes are produced which, if not closely controlled, can have a significant effect on the environment along with the health of workers and local residents.

For one sand mixer manufacturer, this was unacceptable, and they decided to make fundamental changes to their systems in order to improve operational efficiency and reduce environmental impact.

Looking to reduce the polluting impact of its sand mixers without compromising their performance, the operator approached world-leading chemical dosing pump specialist SEKO to deliver a solution.

SEKO’s technical team carried out a comprehensive assessment of the client’s system and discovered that the existing process dosed furan resin and benzenesulfonic acid into the crude sand via a gear pump which, while providing high output, was considerably lacking in accuracy.

This inevitably caused excessive chemical dosing which, as well as causing costly wastage, exacerbated the emission of polluting gases. In addition, the existing equipment was noisy, caused large flow and pressure pulsations and had a high maintenance requirement.

Taking into account the client’s specific process requirements along with the nature of the additives being pumped, the SEKO technical team recommended the Spring MS1 mechanical diaphragm dosing pump for an accurate, reliable and cost-effective alternative to gear pumps.

The Spring MS1’s analogue-controlled dosing accuracy meant that the binders could be metered in proportion to the volume of crude sand, resulting in a consistent mix while minimising chemical wastage. Meanwhile, the pump’s high-grade PTFE diaphragms and PVC/PVDF head – known for their superior chemical compatibility – were considered ideal for handling the aggressive benzenesulfonic acid and helping to ensure the pump’s reliable, long-life performance.

The Spring MS1, with its zero-leakage profile and impressive low failure rate, is proven to be capable of continuous dosing. This is in part due to an intelligent ball valve design which allows the component to be easily removed for cleaning without the need for regular shutdown maintenance – minimizing the client’s running costs.

The flexible Spring MS1 was also an appealing choice due to its capacity for receiving ancillary products, including variable-frequency motors and pulse dampers to further enhance chemical dosing consistency. Meanwhile, the pump’s back pressure valve ensures accurate dosing even in the event of a change in water pressure within the pipeline.

As well as an improvement in the overall dosing performance of the resin sand mixer, the client has seen a significant reduction in the emission of pollutants, allowing them to protect workers and neighbours while reassuring existing and prospective customers that their product is environmentally responsible.

Another example of a SEKO solution helping customers achieve long-term, cost-effective improvements in their daily operations.

Spring MS1 series

Mechanical diaphragm metering pump with spring reset mechanism and aluminium housing.

Features

• Flow rates: 5.5-1,200 l / h
• Maximum pressure: 10 bar
• Diaphragm diameter: 64-165 mm
• Motor: Standard power 0.18-0.25-0.37-0.55 kW (IP55)