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‘Spiroflow’ Big Bag Discharger – made for the job!

The managers and operatives at Colin Stewart Minchem’s Winsford, Cheshire site are pleased with the performance of their ‘Spiroflow’ Big Bag Discharger even though it is not being used for the job it was originally bought! Colin Stewart Minchem Ltd are soon to change their name to AMCOL Minerals Europe to better reflect their business activities. They are part of the AMCOL International Corporation; which, through its operating subsidiaries, is a leading international producer and marketer of value-added, specialty minerals and related products. The Company’s products serve 12 major markets, including detergents, personal care, speciality minerals, pet products, building materials, metal casting and humidity control products.

The Company was established in 1927 and is headquartered in Arlington Heights, Illinois, USA. AMCOL operates over 50 facilities in Asia, Australia, Europe and North America. They employ approximately 1,500 employees in more than 15 countries.

At Winsford, Cheshire their subsidiary, Colin Stewart Minchem employ around 80 people mainly producing raw materials for detergent manufacture and specialty minerals for oil field operations. More than 80% of their production is delivered to destinations right across Europe as witnessed by the constant comings and goings of left-hand drive lorries.

It was here at Winsford that, in 2004, they took delivery of their ‘Spiroflow’ Big Bag Discharger bought specifically on the recommendation of a customer. In the event, the customer changed the particular product formulation and, as a result, the Spiroflow unit was not required. Colin Stewart Minchem put their ‘Spiroflow’ Big Bag Discharger in to mothballs – but not for too long. During 2005, they became involved in the negotiation and winning of another contract that involved the mixing of minerals with chemicals. One of the chemical ingredients is supplied in big bags and is, according to Technical Manager, John Withenshaw, ‘Super moisture sensitive and, it is critical to the process that it is maintained in a dry condition before being introduced in to the mixer’.

The specification of the ‘Spiroflow’ Big Bag Discharger for its original duty called for it to be manufactured to operate within an ATEX Zone 21 environment. This was not a problem for us as we are well placed to meet such requirements. However, there are no ATEX considerations associated with the current application, but that is the only aspect of the design that has not been crucial to the success of the application. The discharger is fitted with bag massagers – essential to ensure the flow of this finely divided, cohesive, super moisture sensitive additive. The discharger is fitted with spring-loaded bag support arms which stretch the bag as it empties – essential to ensure complete discharge of the contents. The discharger is complete with a spout closure device – a big advantage when you are discharging around 5 batches from each bag and you need to ensure that no moisture can get into part used bags. The discharger has a dust containment cabinet with bag liner clamp – additional help in keeping moisture out of the product. The bag support frame and screw conveyor are mounted on load cells – essential to ensure that the correct amount of this super moisture sensitive ingredient is added to each batch. So, although, the discharger was not originally made for its current application – it is ‘made for the job’!

Product is removed from the ‘Spiroflow’ Big Bag Discharger via a horizontal screw which feeds a refurbished Aero-Mechanical Conveyor which was already on site. The Aero-Mechanical Conveyor in turn delivers ingredient to the mixer on the mezzanine floor above. The ‘Spiroflow’ Big Bag Discharger has been in operation since January 2006 and as John Withenshaw confirms, ‘It is tremendous! The load cell set up is really good and the accuracy is great’.

More information about Colin Stewart Minchem and AMCOL International Corporation can be found at and