Pneumatics

Currently, and for good reason, much attention is being focused on the conservation of energy. Compressed air, like electricity and gas, is an energy resource. It has often been referred to as the third utility. As with all energy sources, our global environment demands that it be conserved and used wisely.

With the recent and future increases of the cost of energy, operating a wastewater treatment plant (WWTP) as efficiently as possible has become one of the most important factors that operators and managers are facing today. The implementation of a properly designed aeration control system has been reported by the United Sates Environmental Protection Agency to reduce aeration energy by 25 to 40 percent.

Back when gasoline was 35 cents a gallon, the term “environmental technology” was not well known. Engineers did not often promote the benefits of building low-energy consumption pneumatic valves among their peers. Recycling or conservation of resources was seldom discussed with any seriousness. In reality, the conversation was more likely to have turned to the muscle cars of the day and how much horsepower they would generate.

A plastics molding plant had engaged us to conduct an ‘on-site’ Energy Assessment of their facility. The annual ‘spend’ for electricity, natural gas, and water was about \$3.2 million for this modern 275,000 square foot, fully air-conditioned facility. During the Review, several opportunities were identified and delineated in lighting, HVAC, process ventilation, the water systems and energy supply contracts. However, the most significant savings were in their compressed air system.

Machine builders aiming to improve the energy efficiency of their machines tend to focus on using energy media other than pneumatics (typically electro-mechanical or hydraulic) since pneumatics, as traditionally applied, is viewed by some as inefficient due to factors like leakage and over-pressurization (i.e.: supplying a higher pressure in an actuator to accomplish a task which is endemic in practice). But they shouldn't, with its low cost of ownership, pneumatics when properly used remains a viable and many times preferable energy source for a given application. When generating and using compressed air, it's true that there are many places in the system where energy can be lost, however targeted measures within a comprehensive energy saving concept can prevent these losses and significantly reduce energy consumption at the machine level.

The PET industry is in a state of flux right now. A number of new bottle blowing facilities are being brought on-line. They are in the “discovery” phase right now as they realize how challenging the required compressed air systems are to manage – from an energy efficiency standpoint. The average high-volume stretch blow molder (SBM) working with PET usually has 2,000 to 4,000 horsepower of installed air compressors with the related energy costs running between \$1 to \$4 million per year. This typically represents 35-40% of the facilities’ total energy bill.

Many passenger cars on roads in Germany contain efficiency concepts that make a considerable contribution to lowering emissions. Automotive manufacturers such as VW have gone even further than this, by applying efficiency strategies in their own value added chain. Because the benefits of pneumatics in automotive industry production processes have seen pneumatic actuation win over other drive technologies, efficient use of compressed air plays a key role in increasing energy efficiency.

Pneumatic air cylinders play a major role in allowing a modern sawmill to produce at the high-speed production rates required. Stable air pressure is critical to allow the air cylinders to respond in a timely manner and avoid any production delays.

Kneeling modules are quickly becoming the centerpiece of accessible vehicle equipment. This trend began with passage of the Americans with Disabilities Act (ADA) in 1991. Prior to the ADA, about 40% of all transportation vehicles were accessible to persons with disabilities.

Much attention and expense is often directed towards optimizing compressor control, clean-up equipment, system pressure / flow control and main system piping in an attempt to maintain adequate and stable pressure at the end use. Often forgotten are the components of the distribution system between the main system header and the end use.