By Dusan Stefanov, Pr Eng Mech, and Levi Bands of Service First GP
All photos by © Eamonn Ryan|RACA Journal
In 2022, the University of Cape Town (UCT) embarked on an ambitious project to construct the Neville Alexander building for its School of Education department.
The installation of Abanqobi Packaging’s new cooling system in a newly-commissioned production and warehouse facility was a rarity – a project that through careful planning, co-ordination and execution, went off without a hiccup.
Abanqobi Packaging produces high quality bottles for the pharmaceutical industry. Stringent temperature regulations are a ‘must’. Thus, accurate and continuous chilled water supply is essential to achieve the product quality and quantity expected by Abanqobi. The project involved installing two Trane scroll type air cooled chillers, a buffer tank, a plate heat exchanger, two secondary circulating pumps with VSDs and the associated piping, electrical and control systems. The project started in March 2022 and was completed in November 2022, despite the varying lead times of the different moulding machines that the cooling system had to serve. The cooling system was designed to meet the specific requirements of the manufacturing equipment components, which needed different temperatures and water flow rates. The Trane chilled water plant management system was adopted to ensure accurate and efficient control of the cooling system throughout the production cycle.
The manufacturing and delivery of the various moulding machines was a challenge, as lead times varied per manufacturer. We had to co-ordinate the installation around the arrival of the moulding machines while sticking to the programme required for wet trials. We adopted a phased approach so that chilled water could be supplied at the required start dates. Project phases:
- Piping infrastructure, including chillers and pumps
- Electrical switch gear and wiring
- Plant control system
- Final connections to the manufacturing equipment
In terms of the design specifications, the manufacturing equipment components required a supply of various temperatures and water flow rates. This was achieved by adopting a primary and secondary chilled water network, plus incorporating a plate heat exchanger to control different temperature circuits accurately. Adopting the Trane chilled water plant management system aided in accurately controlling the various requirements throughout the production cycle.
1 and 2: The cooling system comprises of two 367 kW Trane scroll type air cooled chillers.
The cooling system comprises of two 367 kW Trane scroll type air cooled chillers. Each chiller was supplied with their own internal primary circulating pump. The chillers operate as duty/ stand-by, ensuring redundancy in the facility. A buffer tank along with a plate heat exchanger was incorporated for system volume and temperature control. Two secondary circulating pumps with VSDs were installed. Their role is to provide various flows to the moulding machines.
The only difficulty experienced on site was a lack of stable and continuous power supply. The customer overcame this issue by implementing a generator. The system is highly efficient. Scroll chillers with multiple step control, implemented on this project, capitalise on part load efficiency during the variable load conditions during productions. Also, by adopting VSD control with a Trane plant manager, we managed to reduce in-rush current during start-up, and to mitigate peak load electrical consumption. Superior control strategies were implemented to make the system as efficient as possible, while the chillers have been providing excellent performance and reliability.
The whole HVAC project was done in Revit, by ODA Design, mechanical consultants, and apart from 3D model, accurate piping, fittings and valves bills of quantities were produced as a final result. This was a rare kind of project found these days – one that was implemented smoothly and on time. ODA Design would like to thank all of the participants and the client for their contribution and commitment, which lead to the successful completion of this project.
THE BUSINESS CASE
By Eamonn Ryan, with technical input from Mpho Mashego, Abanqobi plant manager
All photos by © Eamonn Ryan|RACA Journal
3 and 4: The R5B | 22n compressor
Abanqobi Packaging is a manufacturing company that produces PET and PVC bottles for the pharmaceutical industry with bottles coming in different sizes and colours, depending on the products they are used for.
Mpho Mashego – Abanqobi plant manager – says the entire factory is a new installation erected in 2022 that went into production towards the end of that year. The refrigeration system was installed simultaneously with the bottling plant, which was supplied by Arburg, Uniloy and Aoki. “The cooling was necessary because the various machines need to operate at precise temperatures depending on each machine – between 9°C and 15°C. The machines use hydraulics and moulds that have to operate continuously at a fixed temperature, otherwise the machines will malfunction and give errors. The refrigeration system was installed according to the specifications of the machines.
“From the planning and design phases to the installation and commissioning phases, everything went smoothly and continues to do so today,” says Mashego. Agent company Hestico sourced the Arburg machines in Germany and Japan, and on that basis was appointed as the lead agent/contractor. It appointed Service First Group, suppliers of Trane equipment, as the refrigeration contractor which in turn appointed Dusan Stefanov of ODA Design as the mechanical engineering consultants for the refrigeration plant engineering design. “In addition, we worked with different contractors for different parts of the installation such as NC Engineering Projects, as the electricity supply was unreliable and required a generator backup. For the compressors, we worked with Ingersoll Rand, who are the suppliers of the compressors for generating air pressure.”
Mashego explained the manufacturing process of PET and PVC bottles that require a refrigeration installation: PET bottles, or polyethylene terephthalate bottles, are types of plastic bottle commonly used for packaging beverages, food, and other consumer goods. A PVC bottle is a type of plastic bottle made from polyvinyl chloride (PVC) material, which is known for its durability and resistance to chemicals. “Various different types of materials are required for our production, such as PET and PVC for the bottles, while for the hard caps the raw materials are LDPE, PP and HDPE, as well as colourants for the bottles and caps. The Arburg machines manufacture the bottles and caps from these materials, using different moulds for different sizes of bottles. For example, we have moulds sized 100 ml, 200 ml, 375 ml and 500 ml. The moulds are changed on the machines depending on orders,” says Mashego.
The number of bottles produced per day or week varies with the size and type of the bottles, with different numbers of cavities depending on different sizes of bottles – for instance, six cavities for a 500 ml bottle every 18 seconds per cycle; compared to eight cavities for 200 ml bottles in 12 seconds per cycle. The smaller the bottles, the faster the cycle time. The facility can produce 200 bottles per hour for more than 100 000 bottles a week. Off-cuts and reject bottles can be immediately recycled on site.
|List of professionals:||Name of company|
|Architect / Designer||N/A|
|Electrical||NC Engineering Projects|
|Consulting engineer||Wet services||N/A|
|Main building||Existing Facility|
|Contractors||HVAC & R||Service First GP / Ventac|
|Electrical||NC Engineering Projects|
|Controls/Plant Manager||Service First GP|
Trane – Service First GP
“The machines need to attain the requisite temperature before they can start producing the bottles and caps. The temperature is controlled by the chiller, which has a compressor that regulates the water-cooling system. The chiller has an input and an output for the water. The input water comes from the chiller at a fixed temperature, say 15°C. The output water goes back to the chiller after passing through the machine. The output water temperature depends on the machine temperature. If the output water is too hot or too cold, the chiller activates the compressor to balance it. The compressor switches on and off as needed to maintain a stable temperature,” he says.