One container – many tasks: Compressed air station, heat recovery and energy saving
Figure 1. Juha Tuomainen Oy's compressed air container
Juha Tuomainen Oy is a machine shop with iron-clad expertise focused on special grinding. The company's specialty is to continue to manufacture and finish high-precision technology industry solutions, from sports car drive shafts to rock drilling machine cylinders, with extremely precise quality. So precise, in fact, that the tolerances of the pieces are typically from hundredths of a millimeter to even thousandths of a millimeter. Let me also say that the size of a dust particle is typically one or two hundredths of a millimeter.
"Of course, the external dimensions and their geometric requirements are important in determining how accurately the specially ground part is manufactured. Sometimes we also instruct the lathes from which the prefabricated parts arrive to us, so that the required end product is achieved," says CEO Aarne Tuomainen".
Driving along wet and lightly snowed Vestonkatu, you'd hardly notice Juha Tuomainen Oy's technical competence center, as it blends in so seamlessly with its surroundings. However, as you turn into the yard, a 40-foot green shipping container is revealed in front of the facade, the exterior coating work of which is about to begin.
This is not just any shipping container, as inside you will find a compressed air station that uses the latest technology and saves energy.
Juha Tuomainen Oy uses compressed air in its machine shop for machining centers and for cleaning parts.
Figure 2. Aarne Tuomainen demonstrates the pneumatics of a grinding machine
The compressed air station is in use daily from 5 am to typically 10 pm and its task is to ensure uninterrupted production operations. As a result of careful planning, all compressed air lines, ventilation, electricity and automation inside the container have been systematically and neatly installed. We can therefore say that a well-planned project is still half done.
“All the design work for the compressed air container was carried out for us by SmartAir And Energy Oy and we were responsible for monitoring the implementation of the set goals, which were:
✓ ensuring the availability of compressed air
✓ energy savings and emission reductions in electricity procurement when energy is saved
✓ automation of the compressed air station in terms of ventilation and compressor control
✓ Recovery of waste heat produced by compressors and its removal from production during the summer
✓ Improving working conditions in production facilities, including waste heat, noise pollution and air quality.
– the collaboration with SmartAir went well and we are satisfied with the end result, says Aarne Tuomainen, the company's CEO is already in the second generation.
Ventilation automation
Figure 3. Fidelix FX-Spider-X automation controls ventilation and compressors
Fidelix Oy was responsible for the automation of the compressed air station's ventilation. The site has Fidelix's FX-Spider-X, which has a new Linux-based operating system developed by Fidelix.
The central unit controls the ventilation dampers and the compressors' operating permits. Three modes have been created for the user to control the ventilation: winter, summer and control operation, according to which the supply and exhaust air dampers are controlled in parallel. The purpose of the ventilation is to use the air heated in the compressor room to heat the hall.
In addition, a signal post with a green and red indicator light was brought into the hall. The green light indicates that the compressors are allowed to operate, and the red light indicates a fault in the automation or the compressor. The compressors are allowed to operate using a switch in the hall.
"Operating the compressed air station is now easy. We have automation displays both in the compressed air container and in the work control rooms. We can monitor, among other things, temperatures and system pressure at a glance." Aarne Tuomainen.
Compressed air and champagne
Photo 4. Sami Uusi-Erkkilä and Aarne Tuomainen shake hands about the final result.
The solution previously used by Juha Tuomainen Oy consisted of a fixed-speed oil-lubricated screw compressor. It was suitable for producing compressed air, but did not meet the definition of an energy-efficient compressed air station by today's standards.
According to calculations, the previous solution consumed an average of 17.4 kWh of electrical energy, while the new, energy-efficient, demand-driven Kaeser ASK 34 SFC produces the same amount of air for just under 8 kWh.
The new compressed air system is active for approximately 4,500 hours per year, as compressed air is consumed at any given moment, even if the amount varies greatly. According to calculations and estimates, the energy savings from renewing the compressed air system show 46,800 kWh per year.
Accordingly, less waste heat accumulates, and when it comes to the heating season, this missing amount of heat must also be compensated for in some way. It is estimated that 10,000 kWh The annual waste heat loss from compressors is replaced by air-source heat pumps with a COP value of 3.0.
According to calculations made, the actual annual savings could be approx. 40,700 kWh, which corresponds to an annual saving of almost 5,000 euros.
With such a large saving, you could, if you wanted to:
✓ buy at least 69 bottles of expensive champagne per year
✓ heats 1-4 electrically heated detached houses for a year
✓ heating a four-person detached house with an electric heater for 40 years
Sami Uusi-Erkkilä from SmartAir appreciates the cooperation with CEO Aarne Tuomainen.
The attitude was open-minded and open to new solutions, as the goal was a more ecological tomorrow. The energy savings achieved as a result of the project show how even a relatively small company can make significant savings in terms of compressed air costs. In addition to the savings, compressed air production reliability was achieved, waste heat was utilized and working conditions were improved, not to mention how a modern system was achieved.
SmartAir Design Team
We carried out all the design stages with our team of four:
✓ Dimensioning and competitive bidding of compressed air needs
✓ Placement, layout and compressed air diagrams
✓ Piping design
✓ Ventilation sizing and design
✓ Overall management of the electrical and automation component
✓ Collaboration with all contractors involved in the project.
The project was implemented by:
Orivesi Insulation Ltd, Jan Mäkinen
Avitor Electricity Ltd, Arto Vitkala and Kimmo Juntunen
Fidelix Oy Pirkkala team
Ascora Oy, Ari Leppäsalko
“Collaborating with SmartAir was also very profitable financially. SmartAir's ability to compare different technical solutions and ensure the best energy efficiency convinced us when we made the decision to implement the project for us.”
Figure 5. Compressed air container with the end open. The screw compressors in the picture are in the background.
Aarne Tuomainen, Juha Tuomainen Oy