How To Reduce Noise In Pneumatic Systems?

Pneumatic systems are essential in many industry sectors, such as construction, automotive and manufacturing. But their most significant downside is the amount of noise they can produce. Excess noise can aggravate your workers and may cause damage to their hearing.

The EU Directive of 2003 prescribes a maximum noise level of 85 decibels (dB) in any eight-hour work period, which means reducing noise in pneumatic systems is a common workplace problem. You don’t have to put up with this as a hazard of the job – it’s unsafe to do so.

The EU Directive was supplemented in the UK by The Control of Noise at Work Regulations 2005. These reinforce the legally acceptable noise levels necessary to protect human health and safety. Although 85 dB is still the level at which suitable noise protection must be provided, this was amended to 80 dB for the point at which employee risk assessment & training is required.

What Causes Noise In Air Compressors?

While pneumatics might be perceived as a cleaner, quieter and more powerful energy source, the air compressor can produce much noise. Noise levels from a single compressor have been known to attain 90 dB, although the average noise level is nearer to 60 dB. If you’re running two or more compressors at total capacity in your pneumatic plant, you may suffer from severe noise problems. Additional sound output from pneumatic tools and devices adds to the issue.

There are several reasons why your pneumatic systems might be making noise. These include the type of compressor you’re using, its air intake and exhaust system, moving mechanical parts and friction. Compressed air leakage in the system may also increase the overall noise level. Many manufacturing plants have production lines and machinery driven by compressed air, including noisy percussive tools. All these typically produce sound, usually aerodynamic noise, when high-pressure air is discharged through the exhaust port and has to adjust to atmospheric pressure levels.

How Can You Reduce Noise In Your Pneumatic Systems?

You can take several steps to help reduce noise in your pneumatic systems. These include:

• Installing noise-reducing fittings

• Installing silencers

• Installing sound barriers

• Installing sound-absorbing materials

• Installing new noise-reduction technology

• Regular maintenance

Installing Noise-Reducing Fittings

Noise-reducing fittings are designed to reduce the sound levels in your pneumatic systems by changing the direction or speed of the airflow with, for example, flow control valves or diffusers. These create turbulence, which helps to reduce the noise level.

Installing Silencers

Silencers are usually the most common and effective way to reduce the noise your pneumatic systems produce. Silencers, or mufflers, typically reduce the speed at which compressed air is exhausted, thus lessening the noise it makes. You install them in the exhaust ports of components like actuators, cylinders and valves. Commercial pneumatic silencers come in four main types: sintered bronze silencers, expansion chambers, perforated panels and porous-diffusion types. Researchers assessed the best noise suppression capacity of these four types and found that porous plastic silencers were the most effective.

Installing Sound Barriers

You can also take a direct physical approach to noise reduction by installing sound barriers. This means building walls or partitions around the pneumatic devices to block the sound waves they emit, substantially affecting the noise level. Commercially available sound barriers include acoustic enclosures, wall panels and curtains. Keeping your air compressors isolated like this within soundproof enclosures keeps the noise in while letting out exhaust and power. When installing sound-insulated enclosures, ensuring they’re not restricting any cooling airflow is essential.

Installing Sound-Absorbing Materials

You can also build sound-absorbing materials into the walls where your pneumatic system is situated. Where barriers block the sound waves, materials like fibreglass insulation, acoustic foam and ceiling tiles are designed to absorb it.

New Noise-Reduction Technology

Some researchers are also proposing an alternative noise reduction method for pneumatic systems. Instead of using tubes to collect the air exhausted from pneumatic tools and machinery, they’ve been able to soundproof their systems and diffuse the sources of pneumatic noise. This technology is known as the expanded collecting system. With this method, they combine exhaust air from the various pneumatic outlets in a production hall and channel it into one central collector. This collected exhaust air can then be directed outside or neutralised to reduce the noise in the production area.

Regular Maintenance

Regular maintenance and cleaning help any system to run more efficiently. Whenever components like valves wear and malfunction, they’ll give out more sound. You must ensure that every part of the system works optimally to keep noise levels as low as possible. Proper lubrication is also critical in making your machinery function more effectively, thus reducing noise. Not only will you end up with a quieter system, but you’ll be optimising airflow efficiency and improving overall performance.

So, What Should I Do To Reduce Noise In My Pneumatic Systems?

To sum up, you can help cut down noise levels in your pneumatic systems in several ways. Establishing a regular maintenance programme is always a sensible solution, particularly if you can incorporate predictive maintenance. Physical solutions, such as installing noise-reducing fittings, sound-absorbing materials and sound barriers, are also effective. You can go for the popular option and install silencers of various types, or try the new route with expanded air collecting systems. By implementing one or all of these possible strategies, you’ll not only comply with regulations but also make your work environment quieter and safer for your employees.