Compressed air is used extensively in many industries because of its many advantages:
No wonder compressed air use continues to grow worldwide and used extensively in factory automation in all sorts of industries: automotive, bottling, food, pharmaceutical, metal working, wood working and general manufacturing.
In automotive, major applications include:
In the automotive industry the most critical area is in the painting systems, both in factory production and in car repair shops. Air quality is extremely critical to avoid both dirt and moisture in the paint. Moisture is especially critical and adequate filtration is a constant challenge in these systems. Nex Flow has two solutions available which have addressed these issues in paint systems. One is the Expel filter which is ISO 12500 tested and guarantees a 99.9999% moisture removal and minimum 1 micron particulate removal. They are ideal for larger shops and factory environments. A lower cost Super Separator which guarantees 99.99% moisture removal (but no particulate size guarantee) is used in smaller shops along with regular membrane filters to address particulate for moisture control.
Another critical area that requires moisture and dirt control is at the assembly stations where air tools are used for part assembly.
In the bottling industry, compressed air quality is even a bigger concern as most countries have strict regulations in place to control the level of hygiene required. In order to protect consumers against ill health (or worse), most industrialized countries have strict regulations and laws governing hygiene of beverage products which must be adhered to during preparation, processing, manufacturing, packaging, storage, transportation, distribution, handling, sale and supply. Compressed air is part of this process from preparation to packaging. This involves the use of oil free compressors in some cases and special filters for the beverage industry depending on the application.
When considering air purification equipment, coalescing filters are vital for the cost effective operation of any compressed air system, regardless of the type of compressor installed. A purification system will normally consist of two coalescing filters installed in series to remove water aerosols, oil aerosols, atmospheric dirt, micro-organisms, rust and pipe scale. Even with oil free compressors, a dual coalescing filter installation ensures high quality compressed air with the additional benefits of lower operational costs and minimal maintenance compared to a single high efficiency filter, and the second filter in a dual system addresses any possible contaminant carryover.
The level of filtration is defined by whether the compressed air is:
For the most critical, contact air, absolute removal of solid particulates and micro-organisms is performed by a sieve retention or membrane filter. They are often called sterile air filters as they also provide sterilized compressed air. Filter housings are manufactured from stainless steel to allow for in-situ steam sterilization of both the filter housing and element. It is important to note that the piping between the sterile filter and the application must also be cleaned and sterilized on a regular basis.
Treatment at one point alone is not enough and it is highly recommended to treat compressed air prior to entering into the distribution system (usually in the compressor room or at point of generation) to a specification that will provide contaminant free air for general purpose applications and protect air receivers and distribution piping from corrosion and damage. Point of use purification should also be employed, with specific attention being focused on the quality of air required by each application. This approach to system design ensures that air is not “over treated” and provides the most cost effective solution to high quality compressed air.
One of the biggest issues in a bottling operation is factory humidity – it is a wet environment. One thing that some bottling plants do for their electrical and electronic control panels is to insert a small compressed air line into the control panel. This is used to purge the cabinet of the humid, wet air that can cause damage to the internal controls. Our Frigid-X Panel Coolers are ideal for these environments because they not only do the work of an air conditioner without the maintenance involved (often quite high in such situations), but they also purge and keep out the humid environment.
Engineered air nozzles, air knives and other blow off products are used to dry bottles, and other containers in the filling and packaging process. These types of blow off products also reduce noise which is quite prevalent in bottling.
Compressed air in the food industry has the similar issues for air quality as in bottling, and the same standards apply for whether the compressed air is classified as contact, non-contact or high risk non-contact. Depending on the type of food humidity may not be the issue. But many applications for compressed air used for drying and cooling arise. For example, baking is a major component of the food industry. Control panels beside ovens often have cooling issue that our Frigid-X Panel Coolers can address, offering a maintenance free air conditioner that lasts long in a high temperature environment around the oven. Many blow off and cooling applications exist in the food industry whether it’s for bread, cake, pudding, ice cream, meat, potatoes, etc. Engineered nozzles, air knives, jets and amplifiers are commonly used to clean and dry.
For example, in one baking operation that manufactures muffins, and air knife is used to blow off excess sugar prior to the muffins entering an oven. Excess sugar will burn and make bad muffins. No one likes bad muffins. The air knife pressure and flow is easily controlled so just the right amount of sugar is on the product to make the perfect muffin.
The pharmaceutical industry is particularly stringent as many operations are to a high level of clean room standard. If you have a clean room at a high level, the compressed air must also be to that high a level. The same food industry standards apply but each operation often exceeds those requirements due to the critical nature of medicines produced when air contact occurs to the product. As with the food and bottling industry there are many applications for blow off and cooling requiring properly engineered accessories like nozzles, jets, knives and amplifiers. A great deal of medicines are packaged in blister packs and other plastic packaging so often compressed air is used in conjunction with ionizing systems to eliminate static charge.
Moving away from food, pharmaceutical and bottling and moving back to big industries other than automotive, the compressed air quality required in metalworking and woodworking is much less stringent. There the concern is to have the quality adequate to prevent damage and maintain operation of machines using the compressed air. As these operations can be quite large, other aspects that show up less in the previous industries can be more widespread – one being leaks. This is also true of the automotive industry. Large operations where air quality is not as critical, have other problems to deal with and compressed air leaks, as large source of energy loss is one problem. A regular leak detection program should be created and maintained to find and fix leaks.
Large compressed air systems in these industries (automotive included) tend also have much greater moisture and dirt issues. In metalworking and woodworking, many of the machines that use compressed air require lubrication so there is oil in the systems. However, it needs to be filtered when the oil is not required such as for blow off and point of use filters can achieve that. As with all the other industries there are many applications where engineered compressed air accessories are used for blow off and cooling purposes. The point of use filters should be used to remove any moisture and oil (a water and an oil removal filter). Alternatively, the Expel Filter or the Super Separator can also be utilized, especially if the compressed air system has significant moisture and dirt. The filtration should be enough to prevent clogging of any blow off device used. Recommended is usually at least 10 micron of filtration for water removal and at least 0.3 micron filtration for oil removal in these industries.
Metalworking and Woodworking can have some fairly dirty environments that can negatively affect the controls inside electrical and electronic control panels. A constant air purge system like our Frigid-X Panel Coolers is recommended to keep the controls clean and avoid damage. CNC machine cooling is a particularly popular application for these types of Panel Coolers.
Both Metal and Woodworking can also often have very noisy environments, one matched only by the bottling industry. This is another reason to utilize engineered blow off technology as offered by Nex Flow.
General manufacturing uses compressed air and with a mixture of the considerations used by the above industries. The smaller the operation, the easier it is to maintain compressed air quality with basic filtration (moisture and dirt). Larger operations, however, require a more complex maintenance to ensure adequate compressed air quality and also comes with a higher possibility of air leaks that needs regular monitoring and repair.
To summarize, one cubic foot of compressed air can contain millions of dirt particles, considerable amounts of water and oil — and even heavy metals like lead, cadmium and mercury. If they are not filtered out, operation of the system components, like valves and cylinders, will be negatively affected. Poorly treated compressed air can contaminate control valves, and cause seals to swell and wear prematurely. As a result, the right compressed air preparation is essential for reducing machine downtime, maintenance costs and energy costs. If compressed air can contact food, medicine, or anything which could impact upon consumer’s health, air quality regulations will be more stringent.