‘Spiroflow’ Bulk Bag Discharger and Flexible Screw Conveyor in action at Multisol Ltd, Irlam, Manchester.

Multisol, part of Brenntag UK & Ireland, is a market leader in the formulation and distribution of high value speciality chemicals on behalf of global technology leaders, focusing on aftermarket transportation and general industrials markets. From their Irlam site in Manchester, Multisol supplies highly specialised performance fluids and functional additives to the major lubricant blenders, as well as to industries such as coatings, pharmaceutical, personal care and specialised cleaning. Multisol’s products are used in everything from premium motor oil packages to face creams. The company is divided into three areas: Performance Fluids, Oil Products, and Toll Manufacturing & Contract Packing; with similar business units active across international operations in France, the Ibericas and South Africa. As a result of their partnership approaches into development projects, back in 2008 Multisol invested in a new Aqueous Solutions Facility specifically to manufacture a Urea solution, commonly referred to as ‘Adblue’. This is required by Euro 4 & 5 trucks fitted with Selective Catalytic Reduction (SCR) equipment, where it is used to reduce the NOx levels coming from the exhaust gases into the atmosphere. ‘Adblue’ is manufactured by the dissolution of Urea Prills into a pre-heated, high purity water source. The urea prills are delivered to Multisol in bulk bags, hence the need for an effective discharger system. Once Multisol had won the contract to produce ‘Adblue’, they had to be in production within a couple of months. This required some imaginative plant design by Multisol’s project team so as to only incorporate equipment that could be sourced within the timescale. Their Operations Manager at the time, Richard Hands, had a working knowledge of solids handling and the legislative requirements of such a work station. He identified three potential bulk bag dischargers manufacturers and, after discussions which included technical evaluations, lead time agreements and quotations, Spiroflow was identified as the preferred supplier. Successful witness testing at Spiroflow’s Test Centre in Clitheroe, Lancashire confirmed the decision that the combination of a ‘Spiroflow’ Bulk Bag Discharger and Flexible Screw Conveyor was the correct choice. “There were some teething problems associated with the inlet to the Flexible Screw Conveyor largely attributable to the variance in the flow characteristics of the Urea Prills,” Richard Hands reflects. “Those we tested were extremely free flowing but occasionally they arrive in an agglomerated condition. Working with Spiroflow, we resolved this challenge by installing a heavier gauge spiral and having an adjustable inlet to the conveyor with predetermined settings for each type of Prill that we use”. The ‘Spiroflow’ Bulk Bag Discharger supplied to Multisol is a Type 6 model with integral lifting hoist. 14 bags of Urea Prills are used per batch taking approximately ten minutes per bag to discharge into the chute. The Prills are then conveyed to the top of the process vessel by way of a 17 meter long ‘Spiroflow’ Flexible Screw Conveyor inclined at 45 degrees. The outlet of the conveyor is furnished with an integral slide valve and fan arrangement that prevents the ingress of moisture into the conveyor from the warm water in the process vessel. Every batch of ‘Adblue’ is rigorously analysed by qualified laboratory technicians to ensure that it conforms to the stringent ISO 22241 specifications. Even the smallest traces of metal in the solution can ‘poison’ a catalytic converter, so all metallic contact parts of the system had to be manufactured in stainless steel. Richard Hands confirms, “We are pleased with the performance of the ‘Spiroflow’ Bulk Bag Discharger and Flexible Screw Conveyor and, also, the after-sales support offered by Spiroflow. As with all projects, during commissioning and initial start-up there are issues that arise, some more serious than others, and it is the response to these challenges that identifies if you have made a good decision with respect of your provider. “Spiroflow worked alongside us to resolve these issues and handed over a fully capable unit. It was this partnership which gave me confidence to sign a Maintenance Contract with Spiroflow to ensure that our equipment is always in good working order through preventative maintenance”. Mr Hands, who has subsequently been promoted to the position of Operations Director, concludes, “The significant reasons that I chose to use a Flexible Screw Conveyor as opposed to any other type are its simplicity and reliability.” The Bulk Bag Discharger supplied to Multisol is complete with side and base bag massagers to deal with agglomerated prills, together with bag spout clamps that allow for product discharge only after sealing containment doors, therefore minimising the risk of exposing operators to potential dust hazards. During the latter part of 2011, additional bag massagers were fitted to the Discharger – along with a grid just above the hopper inlet – to cope with bags of prills that were being received in even more consolidated a condition. Site Manager, Darren Copson, confirms that the additional massages have solved the problem by returning the bag unloading process back to its original efficiency.