If your compressed air system has already been in service for several years, it is worth taking a closer look at its current performance. If your compressed air supply is decreasing or insufficiently efficient, costs that you can avoid will add up. There are various measures you can take to counteract this and get your station back in shape again: by carrying out a general overhaul of individual machines, by adding a compressor with speed control to a higher-level control system or a heat recovery system, as well as by using more efficient technology for compressed air preparation and checking the pipe network. All these measures help to reduce operating costs - which in turn reduces the overall life cycle costs, at least in relation to the volume of compressed air produced.
General overhaul: Upgrading old compressors with technical innovations
As the service life of a compressed air system increases, its efficiency decreases and after many years it no longer corresponds to the current state of the art. One reason for this is the incipient signs of wear and tear of the main components in the compressor; these can be delayed by regular maintenance, but not completely prevented. On the other hand, current technical innovations in terms of compression technology, drive, motors or software are not yet used in decades-old machines. The second factor that can reduce the efficiency of a compressed air system over the years is a changed demand situation on the production side, to which the compressed air supply has not been sufficiently adapted. With a general overhaul of a compressor or the retrofitting of individual components, such as a higher-level control system, you can get the full performance out of your plant - and keep the life cycle costs within a manageable range.
Because an inefficient compressed air supply generates one thing above all else: avoidable costs! The energy requirement increases and with it the electricity costs. In addition, older systems tend to be more susceptible to maintenance, although costs can be better planned with regular maintenance. However, if maintenance is neglected, the susceptibility of the compressors to faults increases, which also increases the risk of expensive production downtimes. Operators of existing compressed air systems have a whole range of options for reducing costs and lowering the total cost of ownership (TCO):
First of all, an analysis of the current situation is recommended, which most compressor manufacturers offer today. How high is the compressed air demand on the production side? What is the power consumption of my (existing) compressors? And what is the load/no load ratio? From the values obtained, the efficiency of the system can be calculated and it becomes clear whether you are paying more than necessary per cubic meter of compressed air. It is also possible to check whether the quality of the compressed air still meets your requirements, and to adjust it if necessary.
General overhaul of the compressor significantly reduces the energy costs of compressed air production
Anyone who decides to retrofit their compressor is turning three cost screws at the same time:
- Firstly, energy costs are reduced, because obsolete components are replaced with current variants and modifications that are more energy-efficient.
- Secondly, after a general overhaul, the maintenance effort and thus the costs are reduced.
- And thirdly, the risk of a malfunction is significantly reduced, thus increasing your productivity. In addition, a general overhaul of a compressor ensures that the compressed air quality it produces meets your exact requirements.
Whether and when it makes sense to modernise your compressed air station or, more specifically, to carry out a general overhaul of a compressor is best discussed with your service technician during a maintenance appointment. It is worthwhile to start planning early on in order to optimally coordinate the general overhaul with the needs of your production and to keep downtimes as low as possible. A well-planned general overhaul takes your production planning into account, and all required resources and components are available at the right time - for example, during a planned production shutdown. Only hire experts who can perform the general overhaul efficiently, quickly and with minimum downtime!
You should also budget the resulting costs as capital expenditure in good time. Depending on the age and condition of the compressor in question, a general overhaul can be very expensive. As the most important components - especially the compressor stage - are replaced, the costs can be about half of the original investment. In some cases, it may therefore make sense to consider a new acquisition as an alternative, or at least to compare both options carefully. If you plan the general overhaul in advance, you can flexibly adjust your financial planning. This gives you better control over your maintenance costs or operating budget. In combination with a service plan, the costs can even be spread over several years - at least at Atlas Copco.
Speed regulation and higher-level control reduce electricity costs of the entire system
If, for example, the actual analysis shows high compressor idling rates, you should consider adding a speed-controlled compressor to your compressed air station. In this way, you can optimally coordinate the demand and the delivery quantity. This variant of modernization is most beneficial to you in terms of energy, provided you have not previously had a speed-controlled machine in the station. It is therefore also to be seen independently of a general overhaul; or one of the two solutions cannot replace the other. Compressors with the latest technology of working 30 to 50 % more efficient than poorly utilized load-idle machines. The energy costs for your compressed air production are reduced accordingly.
The use of a higher-level control system also has a cost-reducing effect. This ensures that the compressors are evenly loaded and that they always operate at their optimum, i.e. most economical, operating point. Combined with an intelligent monitoring system, you always have an eye on the performance of your compressed air supply. Changes in efficiency or malfunctions are directly visible and can be corrected. Expensive downtimes are reduced to zero and your productivity increases.
Compressed air preparation, distribution and heat recovery minimize energy losses
Optimizing the processing technology used can also reduce the cost of an existing compressed air system. Modern adsorption dryers, for example, can now manage with a minimum of electrical energy, as they use the heat of compression (HoC) of the compressors for the regeneration process. The option of speed control for the dryer motor further reduces the energy requirement and at the same time extends the service life of the adsorbent material. Costs can also be reduced by using modern compressed air filters to separate dust, aerosols and residual oil. The decisive factors here are a low pressure loss in the filter and the longest possible service life of the filter material.
Combination filters, which combine several functions, enable particularly low pressure losses and simplify maintenance.
Particularly large savings potentials are often hidden in the compressed air distribution system. It is therefore always worth checking the cross-section and routing of the pipe network and optimising it with regard to avoidable pressure losses. Leakage management also pays off in a very short time.
Read an interview on the subject of leakage with Karsten Decker, European Energy Consultant(IHK)
If there are heat-intensive processes or a heating system in your company, you should check whether you can use the waste heat from your compressors there in a sensible way. This can be achieved by using additional ones. Some modern compressors also already have all the components for space-saving integrated heat recovery.
