Hiring someone to perform a compressed air audit is the most straightforward but most expensive approach to enhance your close air operations. A team of seasoned, professional compressed air wizards will come to your facility, spend days monitoring pressures and inspecting your system, and provide you with a list of everything wrong. Then, in many situations, they will urge you to spend tens of thousands of dollars on new compressors and controllers in addition to addressing leaks, faulty plumbing, and other minor problems.
And they will be correct. Following an audit’s recommendations frequently pays for itself in a short period by saving tens of thousands of dollars in operational expenditures.
You are likely to profit from such an audit, but it may be helpful to know what the audit team is expected to discover so that you may spot common problems on your own. To that aim, we asked some of the best compressor manufacturers and servicing firms what they often discover. The ten most common, highest-payback audit target items are shown below.
1. Fixing of Leaks
Leaks are one of the most typical difficulties. According to studies, up to 35% of compressed air generated in the market today is lost due to leaks, and everyone has leaks. Therefore, identifying and rectifying them may save the purchasing price and the amount of energy required to power the compressor.
Plants that do not have a systematic monitored and disciplined compressed air leak-management programme will have a cumulative leak level of 30% to 50% of total air demand. Set up a short-term leak inspection programme in which each plant sector is inspected once per quarter to locate and remedy leaks. During production and nonproduction, inspections should be performed with a high-quality ultrasonic leak finder. All discoveries, remedial actions, and overall results should be documented. It sets up procedures to monitor airflow to each department and makes each department responsible for identifying its air use as a measurable component of the expenditure for that area.
2. Avoid excessive pressurization (compressed air audit)
Excessive pressure causes leaks and wastes money. Some end-users will actively raise the pressure in an attempt to compensate for capacity constraints. In reality, boosting pressure has the opposite impact on airflow and frequently exacerbates the situation. There is also a proportionate link between stress and power usage — every 10 psi of excess pressure results in a 5% increase in electricity expenditure.
Too much high pressure will aggravate issues rather than solve them. The easy solution to many system problems is to increase the pressure. But, unfortunately, the leaks will worsen, and uncontrolled users will squander more air and energy.
Lowering the pressure may fix the problem. Lower system pressures needless mass, resulting in fewer compressors working. In addition, compressors are often more efficient when run at lower pressures.
Often, the most difficult challenge is convincing the production team that the system is dependable enough to respond when needed to drop the pressure demand closer to the actual design requirement.
3. Keeping a check on air requirements
Production frequently underestimates the amount of air required. If the display is permitted to set their compressed air requirements based on as much as they want whenever they want at whatever pressure, the system would never run efficiently. The compact air system’s whole operating paradigm must shift. We must change from the primary aim of keeping minimal pressure and that more significant pressure is acceptable to the goal of maintaining consistent and stable pressure. Plants must shift their attention from maintaining air supply’ to supplying air to satisfy demand.’ More air and pressure means more money.
If you have a limited region that requires high pressure, put up a secondary, smaller high-pressure unit or a good booster rather than operating the entire plant system at the higher pressure.
4. Monitoring the angle connections
Replacing tee connections with directional angle entry connections is one of the most accessible modifications in a compressed air system. Turbulence generated by a 90-degree entrance causes a 3 to 5 psi pressure loss in a pipe system when a compact air feed line is attempting to feed into another aircraft. Such a loss can cost you $1,200 per year at each of those tees. More crucially, the backpressure gives a misleading unload signal to the controllers, resulting in premature unloading or the activation of auxiliary compressors. Using a 30° to 45° directed angle entrance instead of a tee can minimise this pressure loss. The additional expense of a directed input is generally minor.
5. Faulty piping
Convoluted plumbing, piping constraints, aged pipes, and inappropriate pipe diameters are all common causes of pressure loss. In a well-designed system, the interconnecting piping from the compressed air source to the process and header distribution pipework should cause no pressure loss. In many circumstances, merely replacing a segment of pipe is all that is required to improve efficiency. Piping is a significant concern, especially in older facilities or companies that have developed and expanded. Cast-iron pipe rusts with time, releasing rust and scale into the compressed air and causing buildups at various places throughout the system. This affects air quality and reduces the effective internal diameter of the pipe and obstructs the airflow, causing undesired pressure dips and velocity difficulties.
Measuring pressure loss in pipe sections will reveal the worst offenders. If you discover a significant pressure loss in some complicated areas or establish that the pipe is too narrow, the expense of replacing the line frequently pays for itself rapidly. Upgrading to copper or aluminium pipe gives good value for money and optimal delivery characteristics. When upgrading, ensure that the actual pipe diameter is designed to supply the appropriate airflow with the slightest pressure drop.
6. Get rid of obsolete restrictions
Clogged filter elements, forgotten manual drain traps, and ignored separator cartridges can cause considerable pressure dips, reducing capacity and dependability and causing air-quality concerns.
Equipment left installed but no longer in use is an often-overlooked component in the air pipe system that causes pressure loss. Old, disused orifice plate flowmeters, filters, separators, and other items are frequently left in the air system even if they are no longer in service. Because they are rarely utilised or maintained, they often fill with sludge, rust, scale, and other debris, producing an ever-increasing obstruction and pressure reduction as the air goes through. This necessitates an increase in header pressure to maintain the requisite process pressure. You should look for obsolete equipment and unplug it from the compressed air source.
7. Insufficient storage
Inadequate storage space is a typical issue. Across the board in manufacturing and processing, the value of an appropriately sized air receiver and compressed air pipe is undervalued. These tanks provide the first stage of moisture separation to aid in the preservation of compact air quality. However, its principal role is to store and supply compressed air to meet peak demand and minimise excessive compressor cycles.
All air systems will perform better with storage between the user and the process. The quantity of practical storage for any procedure is the point at which the system’s backpressure equalises the operational control band. In one case, a 280-hp, two-step regulated, lubricant-cooled rotary screw compressor was working 24 hours a day, seven days a week at a relatively modest load of 70% flow. However, the device had a minimal storage capacity and would empty, idle for 15 to 25 seconds, then refill.
The bleed-down time for this unit was one minute to achieve full unloaded power. “The unit did not turn off long enough to reach the low powerpoint and spend time there,” van Ormer says. Correcting the adequate storage to almost 10 gals per cfm resulted in a two-minute idle permitting full blowdown to the low idle input power and an entire one-minute run at this low power before reloading. This resulted in an annual savings of more than $14,000.
8. Inappropriate use
Unregulated compressed air consumption and utilising compressed air for improper uses waste a lot of energy. Given that it costs eight times as much to use air as it does to use electricity, you may want to reconsider uncontrolled air-powered cabinet coolers, blow-offs, vacuum generators, mechanical pumps, air motors and hoists, vibrators, aeration, spraying, and a variety of other equipment.
Compressed air is easily accessible in a facility, but the cost of using it is not always precise. As a result, when a need was found, the air was typically the simple solution. It’s even used to cool workers at workstations, blast dust, or power vortex-type coolers and air to keep food clean. It is recommended to utilise high-quality air amplifier nozzles or air inducers wherever feasible to decrease blow-off compressed air by 50% or more.
9. Watch those pumps
Air-operated diaphragm pumps resist harsh circumstances and even run dry, making them a popular choice among plant staff. Is an air-operated pump, however, the ideal solution? Electric motor-driven diaphragm pumps are widely available and may operate just as well. For example, a 2-inch air-operated diaphragm pump pumping water at 130 GPM will utilise 25 hp of compressed air at a cost of $9,947 per year. A 3-hp electric pump with an annual energy expenditure of $1,989 might achieve the same. (compressed air audit)
If air-operated pumps must be utilised, consider incorporating controls to turn them off when not in use. Pumps squander the most air while they are doing nothing. Check to see if the pump is running at the lowest feasible pressure. When needed, simple controls can be used to boost pressure. (compressed air audit)
10. Maintain the system
Poor air quality harms industrial operations. You want clean, dry air, which necessitates the upkeep of filters, separators, and driers. Neglecting prescribed maintenance might allow oil to enter the plant air and cause production issues ranging from leaking tools to fisheyes in paint systems.
Inadequate maintenance harms efficiency. Van Ormer claims that they discovered three 150-hp compressors with 9.5 psi input pressure during an audit instead of the standard 14.2 psi. This lowered the effective production from 725 cfm to 501 cfm, a 31% drop. To meet the 1,400 cfm demand, the factory needed to run all three compressors at maximum capacity. An investigation revealed unclean and constrictive inlet conditions. The problem was fixed, which resulted in an annual savings of about $45,000 in energy. Change air/oil separators, filters, and other components when they are needed, not when they clog and cause pressure loss.