Beyond the conventional from
July 27th 2007

The hardest part of change is to give up what you believe is to be true and try something different. Often conventional thinking provides the same results. Therefore logic would dictate that to make things better you must apply non conventional thinking. Conrad Hunt, Marketing Manager for Ingersoll Rand Industrial Air Solutions explains how you can achieve a reliable air system, make improvements in productivity and of course make more profits.

While variable speed control systems have been used in industry for a number of years, the limit of this technology has always been in the application of induction motors. These restrictions have prevented the variable speed compressor from reaching its full capability.

That is until Nirvana was introduced by Ingersoll Rand! Simply put, Ingersoll Rand’s Nirvana goes far beyond traditional or conventional inverter duty induction motor designs. Through the exclusive use of the Hybrid Permanent Magnet Motor, all the potential benefits of variable speed technology are now unleashed.

The amazing innovation of the HPMTM Motor has resulted in the installation of thousands of Nirvanas, saving millions of kilowatt-hours per year and increasing the reliability of plants across industries worldwide.

Conventional speed control, using an “inverter duty” induction motor with variable frequency drive provides:- Stable pressure, improved part load efficiency and soft starting, The Nirvana solution is light years ahead offering stable pressure, improved part load efficiency, soft starting and so much MORE….

Additionally the HPM motor is totally maintenance free by design! All bearings, couplings and the potential for misalignment are a thing of the past. This simple design offers a major advancement in reliability. Induction motors lose efficiency as they part-load through speed reduction yet the HPM delivers unprecedented performance at virtually constant, best in class efficiency throughout the speed range. When demand is below minimum, most variable speed compressors continue to run unloaded to protect the motor. Infinitely better, the Nirvana turns off immediately avoiding wasted energy, since the HPM has absolutely no limitation in starts and stops.

The latest benchmark for long lasting reliability, the Nirvana HPM motor and matching drive, are conservatively rated to operate continuously in temperatures up to 46º C.

The HPM Motor unleashes the full potential of variable speed technology through:

• Stable pressure,

• Improved part load efficiency

• Soft starting,

• Maintenance free operation

• Unwavering best-in-class efficiency

• Unlimited Stops and Starts

• Highest motor temperature rating

Simply put, the Nirvana Hybrid permanent motor delivers Superior value through leading innovation When coupled with the time tested Ingersoll Rand rotary oil free or contact cooled airend, efficiency and reliability take a giant leap forward.

At the heart of every Nirvana, oil free compressor is the technologically advanced two-stage oil free air-end providing unequalled reliability. One hundred percent oil free integrity is delivered through the use of vented multistage, mechanical seals increasing peace of mind year after year.

Stainless steel rotors provide maximum protection and increased life for the demanding 2nd stage environment.

Rotor coatings which enable close clearances are essential to the reliability and performance of oil free compressors. Traditional rotor coatings decay with normal use, deteriorating performance and overheating, compromising delivered air quality and jeopardizing sensitive processes and overall reliability. This decay simply means less delivered air; more power consumed, and reduced operating life.

Ingersoll Rand solved this problem with the highly advanced "UltraCoat" surface coating process. Mechanical and molecular bonding to the substrate solidifies UltraCoat as the most durable oil free rotor surface eliminating the probability of decay. The Nirvana Intellisys controller embodies unique control features which enable the Nirvana to consistently deliver its full potential.

Simple to set-up, operate, and adjust the operation of a single unit, the Nirvana Intellisys is also able to easily “master control” multiple units and or communicate with building management systems. On board control of the cooling system variable speed blower ensures compressed air quality, ensuring a stable discharge air temperature, is delivered to the air treatment equipment while at the same time avoiding overcooling.

The patented “adaptive pressure control” maximises the output capacity by accommodating fluctuations in system pressure losses, a significant improvement in compressor control.

INTELLISURVEY AUDIT

In the medical community, prescription without diagnosis is known as malpractice. In compressed air, a solution without problem definition is guessing. Everyday, facilities personnel commit compressor malpractice by responding to a symptom in stead of discovering the real problem. A symptom may be low air pressure, which is certainly a problem to production, but the root cause of the low air pressure could be any number of reasons. That’s why Process Analytical Technology is critical to solving problems and developing repeatable processes. At Ingersoll Rand, measurement is the first step. Monitoring the compressed air system helps us determine root cause of issues and identify potential improvements in the system. Subjectivity, or more simply put, guessing, is removed with data.

A simple tool, known as Intellisurvey, accomplishes the data collection challenge simply and non-intrusively. Flow, pressure, supply utilization and power costs are all analyzed to determine an optimized system which generates improvements in repeatability, efficiency, and plant productivity.

The report generated defines the compressed air system with its many components and interconnecting piping. Raw data is graphed and trends are identified. At a sample rate of 1 second, over 600,000 data points are collected in just one week.

Methodology is explained for simplicity, and summary tables for power and flow statistics are generated. Load Duration and Base Load profiles are also formed. Complete analysis by competent system experts reveals true opportunities for improvement. Proposed Improvements are easy to understand as a new system schematic with interconnecting piping is drawn with the changes to design outlined in a new colour.

Compressed air malpractice occurs everyday at great expense to many businesses. Production stoppage, product spoilage, extended downtime, overpressurization, and total inefficiency are all results of compressed air malpractice. Stop guessing and define the true problem using data collection, system knowledge and proper analysis.

Whether you are the maintenance manager or company owner without reliable and concise data you cannot make positive business decisions.

Contact your Ingersoll Rand Air System Engineer today to find out how you can begin this problemsolving process.

CAPACITANCE

Essential to the design of a reliable and repeatable air system is Capacitance. Understanding the system capacitance, and how to apply it, is the difference between designing a reliable air system and taking a guess. Unfortunately, most systems are constructed without taking the capacitance into consideration.

What is capacitance? Pressure or Volume? Since pressure readings are readily available from gauges mounted on the tank or compressor, the health of a compressed air system is usually understood in terms of pressure only. Volume of air at pressure, however, is what makes up the mass flow that accomplishes the work. Capacitance, then, is the unit of measure which accounts for a change in volume relative to a change in pressure. Simply put, the units are volume with respect to pressure, such as cubic metres over bar.

Knowing the capacitance allows you to predict how the system will respond to a loss in air power, such as the failure of a compressor or other major event in your system. Calculating how quickly compressor controls need to react and whether system controls will function efficiently are benefits of calculating capacitance.

Assessing Capacitance allows one to make a fact based decision on an acceptable solution. Whether the solution is to increase air storage capacity, make a change to system controls or add an Intelliflow valve, determining capacitance is the first step to stabilizing pressure and maintaining system reliability.

Since capacitance is rarely considered when a system is designed, there is great value in calculating your current capacitance level and more importantly, what level of capacitance is required to optimise your system. This is easily done by assessing the start and load permissive times for each compressor, controller limitations and system controller permissive where applicable. An additional volume assessment of the major system events along with supply response rates will help you calculate what is required to maximize reliability and product quality while minimizing operating costs. Assistance with this profit generating concept is available through your Ingersoll Rand Air System Engineer.

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