Innospec is a global chemicals company with 1,000 employees in 23 countries. They divide their operations into three distinct business areas: Fuel Specialties, Active Chemicals, and Octane Additives. The Active Chemicals business includes companies, one of which is at Ellesmere Port, UK, that produce chemicals used in the manufacture of personal care products.

Customer requirements

The personal care products manufactured at Ellesmere Port are for the European market and, to produce them, they needed a manufacturing plant that replicated a US plant making a similar product. The main ingredient of the product is delivered to site in big bags. For each batch, several bags are charged into the process reactor together with a catalyst from 25kg sacks. The US based plant incorporates an Aero- Mechanical Conveyor to transfer material from the big bag discharger to the reactor. The UK plant was built on a tight budget; accordingly the Aero-Mechanical Conveyor was put under particular scrutiny.

Spiroflow solutions

We supplied a ‘Spiroflow’ Big Bag Discharger with integral Flexible Screw Conveyor as the means of charging the reactor. The 25kg bags of catalyst are manually added through the Discharger’s access doors. Charging the reactor takes an hour - which was the time specified from the outset. Although, we manufacture Aero-Mechanical Conveyors, to assist Innospec to keep within budget we offered a Flexible Screw Conveyor instead.

What convinced Corporate Projects Manager, Bill Swift, that the Flexible Screw Conveyor would do the job was the day he spent in the Spiroflow test centre. As he commented, “We are well satisfied with our ‘Spiroflow’ Big Bag Discharger and although we chose the lower cost Flexible Screw Conveyor, it has proven to be very efficient”.

Our Dischargers are designed to be dust-free. The bags sit on a support dish, its outlet spout passes through a flexible membrane: this forms a dust-tight seal. By way of doors in the dust-tight cabinet below the support dish, the bag neck is pulled down. With the doors closed, for safety reasons, pneumatic spout closure bars pinch the bag spout above the tie point. With the interlocked doors open again, the operator can untie the bulk bag spout. Once untied, the cabinet doors are re-closed, the spout closure bars are opened and product flows into the collection hopper below without escape of dust to atmosphere.

The plant at Innospec is designated a gas zone 2 and dust zone 22 hazardous area. To save cost, the main control panel is mounted remotely outside of the building with a zone rated local control panel adjacent to the Discharger. Being ATEX/DSEAR competent, we had no difficulty in meeting Innospec’s requirements. All our control panels are designed and manufactured in house.

Bill Swift decided on simplicity to connect the Flexible Screw Conveyor to the reactor. Given that the reactor reaches temperatures of 300°C, the flexible connection is simply disconnected and reconnected as required so that the reactor inlet can be closed by a pressure tight hatch once the reactor has been charged.