MechChem Africa January-February 2024

⎪ Water, wastewater and pumping solutions ⎪

liquids. In the food industry, everything from yoghurt with fruit pieces, to various syrups, to glycerine can be handled. “We use too them for pumping printing inks to gently move abra sive inks onto the rollers and doctor blades in the print and packaging industry, and we service some key plants in the mining indus try that handle highly aggressive chemicals,” notes Andrew. He cites a particularly successful early ap plication for Tapflo in South Africa’s catalytic converter industry: “One of our first break throughs in the automotive industry was the use of Tapflo AODD pumps for the manufac ture of catalytic converters. Our pumps are now widely used to transfer the very abrasive sulfuric acid-based slurry that carries the platinum and other exotic ingredients used by the converter. This slurry is pumped into moulds before being baked to form a solid ceramic inner filter. “In terms of the manufacture of this key component, Tapflo pumps are used to handle all the mixing of slurry ingredients to ensure compositional accuracy and the waste-free transport of the value laden slurry into the moulds,” Andrew informs MechChem Africa, adding that to handle the slurry reliably, high density polyethylene (HDPE) pump casings and chemically resistant PTFE diaphragms are used. Handling and mixing of SLES Tapflo also has a separate department that de velops tailor made flow solutions for complex applications. One of these solutions involves a key ingredient called sodium laureth sulphate (SLES), which is widely used in the pharmaceu tical, cosmetics and personal care industries. “SLES is an organic compound that has good cleaning and foaming properties. It is normally sold and delivered in concentra tions of 70%, which then need to be diluted before being added to the end-product. But it is very viscous, which makes it dif ficult to pump and mix during dilution. “What our team developed is a com plex, fully automated and compact sys tem that solves a host of the problems end-user clients were experiencing. The first problem was to thoroughly mix the concentrated SLES with water to the dilution required. Traditionally this used to take six to eight hours using a heated jacketed holding tank and recir culation pumps and stirrers. “By using a combination of positive displacement and centrifugal pump technologies with other inline compo nents, we can convert and dilute the concentrated SLES into the customer’s required diluted SLES using efficient high shear mixing (HSM). This process is significantly faster than the tradi

tional dilution and is completed inline whilst moving through the Tapflo SKID Designed unit. The mixing efficiency is carefully moni tored and controlled by a PLC, which ensures the dilution accuracy and mix quality, and alerts operators of any deviations. “Additives such as perfumes or preservatives can also be dosed into the diluted SLES accurately and inline if needed. The Tapflo SLES system, using various valves and components, then transfers the end-product out of the system directly to process or storage tanks for later use. The result is a consistent, well-mixed user friendly diluted SLES product, produced using far less energy and huge time savings, “Jason Andrew explains. “We also often add some form of automa tion: for batching purposes, to control and monitor the process and to track the mainte nance needs,” he adds. Drum decanting “We also offer simple to tailored drum de canting solutions, from a simple Air Operated Double Diaphragm pump with mounting han dle and suction tube to suit, to more complex automated drum decanting systems. Some of these are developed to meet a specific need,” Andrew continues. “A food producer might routinely take deliveries of ingredients such as tomato concentrate. These need to be safely decanted and delivered to the point of need. “So, we have developed an automated, operator safe decanting system: the operator can decant from a single 210 litre drum unit up to a four-drum system: the HVS Quattro,” he says. These viscous products arrive in a sealed aseptic plastic bag within a drum of varying

The company has also developed a

range of simple drum decanting solutions.

canting unit can handle these drum variables and manage the problematic hygienic bag.

Rotary lobe pumps for confectionery products

Another example that is particularly success ful with multinationals is a pumping system for handling product deliveries such as glucose or maltose. “When pumping sugar-based solutions it is critical to make sure they do not caramelise or solidify, and when the pump is not in use, you do not want air to get into the mechanical seal faces, which will cause crystal lisation and can quickly result in seal failure, particularly on pump unit start-up. Tapflo has developed a comprehensive road tanker offloading and transfer solution based on its rotary lobe pump technol ogy. This is now being used by internationally recognised breweries and several national confectionary plants. Key to the solution is monitoring the line pressures and pump speeds, which enables varying viscosity ranges and friction head losses to be accommodated. “We also put in dry run protection, which is a key cause of premature pump failure, often due to operator neglect. “We've automated the system, so all the driver/operator needs do to offload his tank is connect the hoses, open the appropriate valves and push the start button. The pres sure and pump speed will then automati cally be established to suit the product viscosity and the distance to the storage container,” he notes, adding that a novel solution has been developed to protect the mechanical seals on the pump. Concluding, Jason Andrew says: “Our approach to business at Tapflo is slightly different. When we look for solutions to simple or complex problems, we assess ex actly what the client is trying to do. Then we apply the pump technologies that we believe are the best suited to and most efficient for the end user.” https://tapflo.co.za

dimensions. The custom light mobile Tapflo de Tapflo’s air operated diaphragm pumps (AODPs) made from polyethylene (PE), or virgin PTFE plastics are suitable for handling almost any kind of liquid whether it is viscous, chemically aggressive or with solids.

January-February 2024 • MechChem Africa ¦ 17