MechChem Africa July-August 2023

Dimple Tube technology enhances sugar productivity

The benefits of new technology – developed by Bosch Projects to enhance production capacity of vacuum pans – can be seen in recent installations at sugar mills in KwaZulu-Natal.

with conventional smooth walled tubes. “Although this technology has been de veloped for process equipment within the sugar industry, the new design provides a cost-effective alternative to the conventional means of increasing equipment capacity and improving energy efficiency in various other sectors where shell and tube heat exchang ers are used.” The original concept has been developed, analysed and tested for over three years, through rigorous engineering processes and tests. An in-house automated manufacturing system, coupled with a stringent quality management system, ensures high levels of product customisation, quality control and consistency. As part of the company’s extensive test ing programme, Dimple Tube technology has been installed into an existing batch pan and has now been operational for three seasons. Separate laboratory test results showed an increase in evaporation rates of over 50% at the start of batch vacuum pan cycles and over 20% towards the end of batch vacuum pan cycles. This means an overall batch vacuum pan cycle time improvement of over 30% was achieved, which significantly enhanced pan floor capacity. Another benefit is a slight decrease in graining volume, unlike an increase in graining volume which is normally found with com peting technologies. Lower graining volume reduces initial thermal inertia at the start of the pan cycle, which significantly improves overall pan floor performance. www.boschholdings.co.za

Bosch Projects in the process of installation of dimple tubes at sugar mill.

T he Bosch Projects research and development team has designed and developed advanced Dimple Tube technology to optimise equipment productivity in the sugar industry, reducing batch pan cycle time, improving pan floor capacity and reducing operational costs. “By integrating dimple tubes into batch and continuous vacuum pans, there are sig nificant improvements in processing capacity, through more efficient evaporation rates, heat transfer coefficient, energy usage, massecuite circulation and enhanced crystal quality and exhaustion,” explains Murray Stevens, Sugar Sector Director for Bosch Holdings. “The first pan to be completely fitted with newly designed dimple tubes was installed recently at a sugar mill on the North Coast of KZN and is starting to show improved A new ‘block-buster’ Hydraulic Bulk Bag Conditioner from Flexicon features arched doorway masts that increase overhead clear ance for easier insertion and removal of pal letised bulk bags using a forklift. The conditioner loosens hygroscopic chemicals, spice blends, heat-sensitive prod ucts and other bulk materials that have solidified during storage and shipment, return ing the material to a free-flowing state and enabling bulk bag unloaders to discharge the material through bag spouts. A hydraulically-actuated, variable-height turntable operates in concert with two hy draulic rams to press opposing sides of the bulk bag at varying heights, rotate the bag 90°, and

performance. The Bosch Projects team is cur rently on site gathering the operational data to assess in detail the impact these tubes have had on the pan. “In a current project at another mill, a vacuum pan on refined massecuite is being fitted with dimple tubes. New tubes are in stalled every week on ‘stop’ days, highlighting the ease of installation of this system. The design of dimple tubes is compatible with existing equipment for retrofit applications, which means that simple and inexpensive up grades are possible, with minimal/zero vessel modifications. “Our newly developed dimple tube technology increases the heating surface area of an existing vacuum pan by approxi mately 15% and improves the turbulence and heat transfer characteristics, compared then repeat the conditioning cycle. The num ber and pressure of hydraulic ram actuations, the height of the turntable, and the number of 90° rotations are user programmable at the control panel's HMI. Enclosed on four sides, the conditioner is equipped with full-height, safety-interlocked doors that disable all equipment functions when the doors are open. The system's hy draulic pump can be mounted on the exterior of the safety cage or remotely and requires only an electrical power connection for operation. Available through the company’s Quick-Ship Programme as a stand-alone unit, the conditioner accommodates bulk bags of all popular sizes. It is also available constructed

Dual-arch bulk bag conditioner

from stainless steel for sanitary and corrosive applications, and in configurations integral to bulk bag dischargers that reduce the cost, footprint and loading time of separate equipment. www.flexicon.co.za

22 ¦ MechChem Africa • July-August 2023