Contracting Quotations in Compressed Air/Vacuum Technology
Compressed Air/Vacuum Technology — Requirements Dictate System Design
Variable Costs to Replace Fixed Costs
More and more companies are exploiting the possibility of generating compressed air with a new and energy-efficient system without tying up capital.
Ultra Air is also in the business of customizing these systems: after analyzing the customer’s situation, load profiles and estimated compressed air requirements, the company designs compressed air stations for their specific applications. As they work on the systems, the engineers consult a database containing the full range of compressors and the accessory components made by all the leading manufacturers along with their respective performance data.
The compressed air requirements must be calculated first in order to arrive at the stage where the compressed air contracting model can be developed jointly with the customer. The following questions and issues are relevant to this process:
- Is the compressed air consumption high, average or low?
- Given the importance of the dynamics of consumption as well, how great are the changes in consumption related to volume flow and pressure within one minute, one hour or one day?
- What quality of compressed air is required?
- Does the customer operate one shift or multiple shifts?
What Are the Advantages of Contracting?
The AirScan method developed by Atlas Copco takes the systems to service level, applying the rule of thumb that the standard consumption in the relevant sector of industry should be taken as a basis for calculating the compressed air consumption with a new compressed air installation.
One key argument in favor of contracting and against a company compressor plant is the issue of cost transparency, which is another point emphasized by Kaeser. Precision measuring systems guarantee that only the amount of compressed air that was actually taken out of the network will be counted. Another major advantage of contracting systems besides transparency of costs is the continual optimization of compressed air costs. Not only does Kaeser take care of the operation and maintenance of the plant, it also makes any necessary changes to suit the operating conditions and to meet the latest standards of technology at any given time.
Exactly as Much Vacuum as Necessary
Horror vacui — nature evidently has something against empty spaces. Hence the need for operators to mobilize a great deal of energy and a hefty dose of control engineering in order to maintain a constant vacuum.
These days it is possible, with the aid of regulated-speed drives and direct drives, to generate the exact amount of vacuum needed at any given time. The operating point of the application is now also subject to precision analysis and adjustment with a view to selecting the right generator or matching it exactly to the application.
The future markets for vacuum technology include renewable energy, for example, as well as medical technology, environmental technology and the electronics industry.
The iXL120 pump supplied by Edwards, for example, is a dry pump for semiconductor production. The vacuum pump is said to be the fastest in its class. The average energy consumption is apparently just 550 watts (output at 700-tonne outlet pressure). As such, the manufacturer claims that the product guarantees both high throughput and low operating costs alike. Boasting a maximum throughput of 110 m3/h, the iXL120 claims to be 22 percent faster than other pumps in its class (20-liter chamber). The pump has an optional nitrogen-free flush for processes not involving corrosive gases. There is no need to supply the pump with nitrogen with this option, thus simplifying operation and reducing operating costs.
Edwards is not the only company where energy efficiency is an important feature in vacuum pumps. Oerlikon Leybold Vacuum is also keen to emphasize that its new Dryvac screw-type pump needs 30 percent less energy than its predecessor. In addition to the improved use of energy, the company also claims that the system saves on installation space and is so quiet that people can hold a conversation while standing next to it.