In the world of compressors, there are often significant and unutilized energy-saving possibilities including energy recovery, pressure
reduction, leakage reduction and optimization of operations through correct choice of a control and regulation system as well as the
choice of compressor size.We are going to take a look at some of the opportunities for minimizing the compressorโs operating costs.
The power requirement concept
When making calculations, it is important to apply the overall power requirement concept. All energy consumers that belong to a compressor
installation should be accounted for: for example, inlet filters, fans and pumps, dryers and separators. For comparisons between
different investment alternatives, the use of comparable values is particularly important. Therefore, the values must be stated in
accordance with internationally recognized standards and regulations, for example, as per ISO 1217 Ed.4 -2009.
The working pressure
The working pressure directly affects the power requirement. Higher pressure signifies higher energy consumption: on average 8% more power
for 1 bar higher pressure. Increasing the working pressure to compensate for a pressure drop always results in impaired operating
economy.
Despite this adverse economic effect, increasing compressor pressure is a commonly-used method for overcoming pressure drops caused by an
under dimensioned pipe system or clogged filters. In an installation fitted with several filters, especially if they have been
operational for a long period of time without being replaced, the pressure drop can be significantly higher and therefore very costly if
unattended for long periods of time.
In many installations, it is not possible to implement large pressure reductions, but the use of modern regulation equipment allows the
pressure to be realistically lowered by 0.5 bar. This represents a power savings of a few percent. This may seem to be insignificant,
but considering that the total efficiency of the installation is increased by an equivalent degree, the value of this pressure reduction
in terms of actual savings is more readily obvious.
Optimizing air consumption
optimizing air consumption can have a lot of benefits
By analyzing routines and the use of compressed air, solutions to provide a more balanced load on the compressed air system can be found.
The need for increased air flow production can thereby be avoided to reduce operating costs.
Unprofitable consumption, which usually is a consequence of leakage, worn equipment, processes that have not been properly configured or the
incorrect use of compressed air, is best rectified by increasing general awareness. Dividing the compressed air system into sections
that can be separated using shut-off valves can serve to reduce consumption during the night and over weekends. In most installations,
there is some degree of leakage, which represents a pure loss and must therefore be minimized. Frequently leakage can amount to 10-15%
of the produced compressed air flow. Leakage is also proportional to the working pressure, which is why one method of reducing leakage
is to repair leaking equipment, and thereby lowering the working pressure, for example, at night.
Lowering the pressure by only 0.3 bar reduces leakage by 4%. If the leakage in an installation of 100 m3/min is 12% and the pressure is
reduced by 0.3 bar, this represents a saving of approx. 3 kW.
Regulation method
Using a modern master control system, the compressor central plant can be run optimally for different operating situations while enhancing
safety and availability. Selecting the right regulation method encourages energy savings through lower system pressure and a better
degree of utilization, which is optimized for each machine in the installation. At the same time availability increases, thereby
reducing the risk of unplanned downtime. Also, central control allows programming for automatic pressure reduction in the entire system
during operation at night and on weekends.
As compressed air consumption is seldom constant, the compressor installation should have a flexible design, using a combination of
compressors with different capacities and speed controlled motors. Compressors may run with speed control and screw compressors are
particularly suited for this, as their flow rate and their power consumption are virtually proportional to their speed.
How does energy recovery work in compressors?
When using electricity, gas or oil for any form of heating within the production facilities or in the process, the possibility of fully or partly replacing
this energy with recovered waste energy from the compressor installation should be investigated. The decisive factors are the energy cost in โฌ/ kWh,
the degree of utilization and the amount of additional investment necessary.
A well-planned investment in waste energy recovery often gives a payback time of only 1โ3 years. Over 90% of the power supplied to the compressor can be
recovered in the form of highly valuable heat. The temperature level of the recovered energy determines the possible application areas and, therefore,
its value. The highest degree of efficiency is generally obtained from water-cooled installations, when the compressor installation's hot cooling water
outlet can be connected directly to a continuous heating demand, for example the existing heating boiler's return circuit.
Recovered waste energy can then be effectively utilized year round. Different compressor designs give different prerequisites. In some situations requiring
a large and peaking heat flow, long heat transport distances to the point of utilization, or a requirement that varies during the year, it may be interesting
to look at the possibilities of selling the recovered energy in the form of heat or cooling or electricity, etc.
Do you have an idea for our #expertcorner?ย Let
us know!
Who we are and how Ash Air can help your business!
Ash Air has been around in New Zealand since 1979, and weโve grown into a nationwide company with international support and a
reputation for quality and reliability.We look after all things compressed air for your business!
Reciprocating, Screw, air compressors
Vacuum pumps
Nitrogen
An extensive line of air treatment components
Ash Air's range of Chicago Pneumatic, Alup, Pneumatech, and Quincy compressors are used extensively around the world in industries
ranging from oil and gas to food, automotive and farming, and we bring you these world class compressors here in the land of the long white
cloud.Our technicians are compressed air equipment experts and are dedicated to addressing customer needs. Supported by a 13 locations
nationwide, Ash Air offers one of the widest selections of compressed air equipment and parts available today in New Zealand.
Reliability and Efficiency
With Ash Air compressors, you can count on reliability and high performance for even the most demanding applications. We focus our
efforts on the following:
Your company purchased an air dryer for your compressor, now where should you install it? One of the most common things we see in the
industry are air dryers being stored on top of the compressors. Seems like a wasted space not being used on top of the compressor, right?
Wrong.
Read More…
When using air compressors, there are many variables that are integral to the quality and effectiveness of your compressed air. When dryer
air is necessary, being able to constantly and accurately monitor dew points can be a critical factor to your operation.
Read More…
Compressed air plays an integral role in breweries both large and small around the world. From start to finish, all details in the brewing
process are managed in fine detail and having the right air compressor is no exception.
Read More…
We Kiwi's love our Coffee! Coffee, like all other food & beverage products, must go through a preservation process to keep the
beans fresh during storage and packaging before they reach the consumer. Coffee that is not properly stored after it is roasted will lose a
large amount of carbon dioxide, which lessens its' flavor and speeds up the staling process. One of the most common ways to preserve the
freshness of coffee is the use of nitrogen gas. Learn more here:
Read More…
Air compressors are helpful for an enormous range of applications such as air filling, packaging, tools, HVAC control, and more! One
possible drawback is the amount of electricity they use; air compressors can be a huge drain on energy if used โinefficiency...
Read More…
Air compressors create the energy used by pneumatic tools and processes throughout your compressed air system. The component that connects
everything together is the piping. It is very important to choose the right compressed air pipe to avoid pressure
loss, rust and other problems.
Read More…