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Energy/Energy efficiency
Energy/Energy efficiency Optimise system efficiency with pumps and smart solutions Operational excellence with smart secondary process pumps Anna Hofmann Rising material, energy and logistics costs as well as material shortages are posing new challenges for more and more industries. As a result they are having to find ways of making their processes both more flexible and more efficient. Fortunately, there are tried-and-tested solutions available on the market. Energy efficiency has become a major area of innovation for reducing costs and emissions in the context of the energy revolution. Optimising processes and systems, heat recovery, solar process heating, etc. can reduce energy consumption by more than 10 % [1]. The pumps used are a good place to start. It is important to distinguish here between process and auxiliary pumps: in every production plant there are ‘primary processes’ (where the product – whether it be drinks or chemicals – is in direct contact with the process pump) as well as ‘secondary processes’. The latter might sound slightly less important. But they’re not: these are pumps and systems for water recovery as well as for wastewater removal and circuits for heating (maintaining temperature), cooling (supplying ice and cooling water) and cleaning (CIP, SIP) as well as for dosing. Grundfos has a range of secondary process pumps which is second to none in its breadth (diversity of design) and depth (material varieties, power levels). Planners can achieve surprisingly sophisticated system optimisations by intelligently combining speed-controlled pumps, power ful sensors and smart control algorithms. A classic auxiliary process is the supply of steam. Central steam boilers are typically used for this. The high pressures and temperatures make feeding the boiler one of the most demanding tasks for pumps. The numerous on/off switching cycles cause additional stress for feed pumps. Conventional boiler feed systems have a control valve, a bypass – and usually oversized pumps. The pump manufacturer has developed a boiler feed system that does not require a feed valve because a speed-controlled pump regulates the feed itself by way of a 4-20 mA level sensor fitted to the boiler. Because of the reduction in components – valves, bypass lines, mixing loops to limit flow – the operator benefits from lower investment, installation, energy and maintenance costs. Besides steam, cooling is traditionally required. Here, too, the system’s energy efficiency can be optimised using speed-controlled pumps. A smaller main circulator pump in combination with a small pump for each cooling unit can be installed in place of control valves. The main circulator pump should be set to constant pressure and the circulator pumps in the individual cooling units to constant temperature. The advantage is that the speed-controlled pump can react faster and more smoothly than a motor-operated valve. Dispensing with throttle valves reduces pressure losses and saves energy and money. FC-controlled and intelligent The speed of the pump is controlled by frequency converter (FC) and it should ideally also be able to smartly carry out specific functionalities. Here’s an example of why from the beverage industry: membrane separation technology is state of the art in beverage production, for example for treating mineral well water and for fine filtration. It involves passing the medium to be filtered along a semipermeable membrane under pressure. Speed-controlled pumps not only keep the filtration speed constant, they also record the pressure difference in the event of increasing filter resistance caused by a blockage and thus ensure a constant volume flow rate. If a constant produc- Pumps in secondary processes Fig. 1: Boiler feed with speed-controlled pumps and no feed valve. 14 PROCESS TECHNOLOGY & COMPONENTS 2022
Energy/Energy efficiency Fig. 2: Reverse osmosis plants play an important role in water reuse. but experience shows that the pump installation itself is rarely adapted accordingly. How can the operator check the actual state of the installed pumps? An energy check by the pump supplier in accordance with ISO 14414 on the energy rating of the pump systems (the result has a calculated accuracy of +/- 10 %) can show what the targeted use of high-efficiency pumps can actually achieve. The operator will discover in a surprisingly simple way (by comparing the performance data of the existing pumps with state-ofthe-art high-efficiency pumps) how to reduce operation costs (energy, water) while also cutting CO 2 emissions. tive capacity is required, a flow meter delivers the current actual value and the pump corrects the rising back pressure by increasing the speed. In addition, changes in state at the suction end of the pump can be corrected, for example when converting to tanks with varying inlet heights. With the iSOLUTIONS concept, the supplier offers the right solution for such requirements. These are a combination of in-house and manufactured components ranging from hydraulics, drive solutions, sensors, control and security modules to measuring and communications units and a smart analogue digital hybrid system which adjusts to the requirements of various applications. Energy check and pump audit As long as technology works, its efficiency is rarely questioned – often because it is very difficult to record the energy consumption of each machine. The result is a bottomless pit Fig. 3: The Energy Check is a pump survey by the customer or a member of the pump supplier’s staff with subsequent analysis/calculation by the supplier. for the operator, but nobody knows that unless they properly look into it. Moreover, plants change over time as a result of production conversions, For complex plants and cases with significant savings potential, the company recommends a more in-depth survey in the form of a pump audit Our competence for your success. WITTE Core Command ® - The pump control system for full process management. Autotuning-Function Batch and manual operation High metering and repeat accuracy WITTE PUMPS & TECHNOLOGY GmbH Lise-Meitner-Allee 20 25436 Tornesch Tel. 04120 70 65 9-0 www.witte-pumps.com sales@witte-pumps.de
