Energy-Efficient Vacuum Supply for Food Packaging by Busch
The vacuum technology specialist showed where energy-saving potential in vacuum packaging exists and how this potential can be easily used. For this purpose, the vacuum supply must be analysed together with the entire packaging process and all parameters must be optimally suited to fit one another. Busch offers this service in the form of a special “VacuumAudit” The goal of this audit is to achieve optimum energy efficiency for the packager.
Busch central vacuum system in a large meat processing business (Image: Busch Vacuum Pumps and Systems)
During this VacuumAudit, the current state is evaluated and suggested solutions are developed for the customer.
The vacuum pump is the core of a packaging machine s vacuum supply. Busch unveiled the newly developed R 5 RD vacuum pump for the first time. The R 5 RD requires 20% less motor power than the previous models. The new vacuum pump is based on rotary vane technology that has been proven through decades of use and was further optimized to make these energy savings possible.
For example, if a thermoforming packaging machine is equipped with the new R 5 RD 0360 A. the annual electricity costs saved during two-shift operation at ten cycles per minute with a chamber volume of 20 litres are EUR 850 (price of electricity = 0.18 euros/kWh).
Reducing thermal load
As a general rule, vacuum pumps generate waste heat that can negatively affect production and processing rooms or their air-conditioning systems. The waste heat can not only be drastically reduced. It can also be utilized.
An oil/water heat exchanger on an R 5 rotary vane vacuum pump can significantly reduce waste heat and thus reduce the energy costs for air conditioning. Furthermore, the heat exchanger can be used to generate warm water, which can in turn be used as warm water during operation. R 5 rotary vane vacuum pumps can be retrofitted with heat exchangers.
If four packaging machines operate in one packaging room and each is fitted with an R 5 rotary vane vacuum pump with 5.5 kW of motor power, the energy required for cooling is approximately 6.0 kW. If the vacuum pumps are operated with a heat exchanger, the energy requirement for cooling is reduced to approximately 1.5 kW. During an operating time of 4,500 hours/year and an assumed electricity price of 0.18 euros/kWh, this results in annual energy cost savings of approximately EUR 5,000.
The use of warm water is not taken into account in this example.
Controlling packaging processes
If one observes one cycle of the packaging process more closely, it turns out that the actual evacuation time in which the vacuum is required only accounts for one third of the cycle time. The rest of the time is taken up by transportation, sealing, ventilation and, sometimes, treatment with gas. Using intelligent technologies in the vacuum supply – from an optimized control system to frequency control through to use of a vacuum container – there are several options for optimization. Busch presented these at IFFA and is also able to discuss these with customers in a VacuumAudit. Energy savings of up to 60% can be achieved.
Central vacuum supply
Any company that packages foodstuffs on several thermoforming packaging machines, tray sealers or chamber machines should consider using a centralized vacuum supply. Busch is the largest manufacturer in the world of these kinds of centralized vacuum systems and therefore has the most experience. With centralization, energy cost savings of 50% and more can generally be expected. This is possible because fewer vacuum pumps are required for this than for a decentralized vacuum supply. Furthermore, performance control can be precisely adjusted to fit the requirements of overall operations. Normally, not all packaging machines run at peak load, so all of the vacuum pumps are not always in operation. Also, centralized vacuum systems offer maximum reliability and safety as all systemically relevant components have a redundant design. If a vacuum pump fails or needs maintenance work, full vacuum power remains intact. Busch central vacuum systems can be equipped with various vacuum pumps. In addition to oil-lubricated R 5 rotary vane vacuum pumps, dry Mink claw vacuum pumps or COBRA screw vacuum pumps can also be used as components. The investment costs can be reduced during purchasing by including already existing vacuum pumps in the system installation. In the process of centralizing the vacuum supply, one manufacturer of meat products realized energy savings of EUR 151,000 per year.
Source: Dr.-Ing. K. Busch GmbH