Inhalt

Not all air compressor dryers are created equal. Knowing the different types of air compressor dryers will help you understand how they work, what problems or benefits they have, and which ones are appropriate for your application.

Main types of Air compressor dryers

There are three main types of air compressor dryers:

1.     An oil/moisture separator dryer
2.     A desiccant wheel type of dryer
3.     A refrigerated dryer or liquid line filter drier (LLFD)
4.     Chemical Air Dryer

Oil/moisture separator air compressor dryers

Oil-water separator air compressor dryers are the simplest and least expensive. To understand how they work, let’s first start with a little background information on moisture in compressed air systems to put the effectiveness into context.

Moisture content in compressed air systems

In a typical oil-injected rotary screw compressor, approximately 7 to 9 pints (3.5 – 4 liters) of ambient temperature condensate will form for every 1000 cubic feet (28.3 m³) of air compressed, and about 3% – 5% of the oil applied will be lost to moisture and varnish formation.

Some compressed air systems may produce as much as 100 pints (45 liters) per 1000 ft³ (28m³).

Effectiveness of oil/moisture separator dryer

The effectiveness of an oil/moisture separator dryer is typically 50% on the first pass and 90% after the second pass. The amount of system makeup air required by a desiccant wheel-type compressor dryer is usually some percentage less than that required by an OWS.

Desiccant wheel type of compressed air dryers

A desiccant wheel type of compressed air dryer typically consists of multiple parallel flow paths separated by fiberglass or metal mesh screens coated with a bed of silica gel beads impregnated with potassium permanganate, manganese dioxide, activated alumina, activated carbon powders, or other suitable chemicals depending on the desired end-use.

Moisture-laden gas enters the top of the desiccant wheel, where its moisture content is transferred to the chemical coating on the desiccant bead surfaces, which absorbs moisture as water of hydration.

The wheel is rotated slowly, either by an attached motor or by the airflow through the wheel to expose progressively more of its surface area to desiccant surfaces as drying progresses. Compressed air exits the wheel through spaces between the beads and drier walls or screens.

An oil/moisture separator dryer will typically have a pressure drop across it of about 10 psi (0.7 bar) for a 50m³/hr volume flow rate, while a desiccant wheel type of compressor dryer may have a pressure drop across it greater than 100 psi (7 bar) for that same air volume flow rate at standard temperature and pressure.

Desiccants do not significantly reduce compressed air volume.

Refrigerated air compressor dryers

A refrigerated compressed air dryer is a type of desiccant wheel dryer that uses a refrigeration cycle to cool the desiccant wheel and provide moisture removal. The use of a refrigeration cycle typically allows the use of a smaller, less expensive desiccant wheel and results in lower operating costs.

The refrigerated compressed air dryer requires a source of low pressure, low-temperature refrigeration. This type of compressor may be designed to use either the suction or discharge gas from an existing centrifugal or reciprocating compressor as its refrigerant source.

Liquid line filter driers (LLFDs)

A liquid line filter drier (LLFD) is usually a small, cylindrical-shaped metal canister with an internal screen mesh media that is designed to remove both water and oil from the compressed air system. A typical LLFD will have a filtering capacity of 10-15 microns.

Liquid line filter driers are an important part of a compressed air system and should be installed in the compressor discharge line between the compressor and the point where the air is distributed to the users.

Compressed air dryers come in many different types, and it is important to select the correct dryer for the specific application. The three most common types of compressed air dryers are the oil/moisture separator dryer, the desiccant wheel type of compressor dryer, and the refrigerated air compressor dryer.

Each type of compressed air dryer has its unique advantages and disadvantages, and it is important to select the type that will best meet the needs of the specific application.

Chemical Air Dryer

Chemical air dryers circulate a liquid chemical through the compressed-air line and also inject the liquid directly into the compressed air as it is being dried. This type of compressed-air dryer can achieve dew points as low as -40°F.

However, liquid injection tends to be less efficient than desiccant wheel drying at removing liquid from very wet systems, and liquid added to the system with this type of dryer may contaminate downstream components such as filters, regulators, and flow meters.

Also, liquid additives injected into the compressed air line with chemical dryers will cause downstream equipment to need more frequent servicing and replacement due to contamination.

Which dryer type is best for your needs?

This is a question that can only be answered after careful consideration of the specific application requirements. Each type of compressed air dryer has its unique advantages and disadvantages, and it is important to select the type that will best meet the needs of the specific application.

The oil/moisture separator dryer is the least expensive, but it will require a compressor with at least 2 stages to provide sufficient air pressure, and additional makeup air must be provided to the system to compensate for the air that is being used to dry the compressed air.

The desiccant wheel type of compressor dryer is more expensive, but it can usually be operated at a lower pressure drop than an oil/moisture separator dryer and does not require makeup air.

The refrigerated air compressor dryer is the most expensive, but it typically requires the smallest and least expensive desiccant wheel, and it has the lowest operating costs.

The compressed air dryer that is chosen must be matched to the specific application and should provide reliable dew point control for the lowest possible operating costs.

The best advice for selecting compressed-air equipment is to purchase only quality components from reputable manufacturers who provide technical support and can offer installation assistance. This will minimize both downtime and maintenance costs.

Produkte empfehlen

Air Tank

Air Dryer

Air Filters

Choose an Air Compressor for Your Business

There are several factors to consider when choosing an air compressor for your business. One factor to consider is the type of compressor you are looking for, which may include single-stage, low noise, and positive displacement. Hope this article helps you make the right decision. After all, your business success will depend on this device! Let’s take a closer look at these factors. Also, consider what compressor manufacturers say about their products.

Positive displacement

Positive displacement air compressors compress air by drawing in a volume from an inlet and extruding it out of a chamber. This increases the pressure at which the gas can be pumped at rates that cannot be pumped through the outlet at lower pressures at higher mass flow rates. These types of compressors are available in single-acting and double-acting configurations. They are classified by the number of cylinders.
There are two different types of air compressors: reciprocating air compressors and screw compressors. Both are roll machines. Positive displacement air compressors use pistons and cylinders to compress air. The resulting air pressure builds up within the compressor housing, increasing the potential energy of the compressed air. Screw air compressors are the most popular positive displacement air compressors, which can be either single-stage screw-blade air compressors or multi-stage screw-blade oil-immersed screw air compressors.
Positive displacement flowmeters use a rotating measuring chamber to divide the fluid into discrete quantities. The number of times the chamber was refilled and emptied was used to estimate the total flow. However, positive displacement flow meters are prone to leaks, reducing the accuracy of the estimates. If a leak occurs, it can cause false readings and damage the compressor. However, leaks in positive displacement air compressors can reduce pressure.
The most common types of positive displacement air compressors are screw, reciprocating, and vane. Rotary positive displacement air compressors are also available as well as many other air compressors. Positive displacement air compressors are most commonly used in large manufacturing facilities. If you are considering an air compressor for commercial or industrial applications, it is imperative to understand how the components of the unit work. Please read the information below to learn more before deciding which application is best for you.
Positive displacement air compressors use a piston to force air into a chamber, compressing the air in the process. The piston moves in the opposite direction, thereby reducing the volume of the chamber. When the amount of air in the chamber reaches its maximum value, the valve opens, allowing it to escape at higher pressure. Positive displacement air compressors are generally less efficient than centrifugal compressors. However, they are still an excellent choice for a variety of applications.

Single-stage

The discharge pressure of the single-stage air compressor is used to control the operation of the compressor. Properly designed load/unload controls allow the air compressor to operate at its most efficient point while minimizing stress on the main engine bearings. Single-stage air compressors can approach variable speed efficiency with appropriate storage capacity. However, improper storage can cause premature bearing wear on the main unit. If this is the case, a single-stage air compressor may not be ideal.
A single-stage air compressor has only one cylinder, which means one stroke is required to move air from one cylinder to another. Pressure is measured in cubic feet per minute or CFM. Tank size is also important as a large single-stage air compressor may be required to operate multiple air tools. Single-stage air compressors can be used in a variety of applications and can last for years.
For the most common uses, single-stage air compressors are the most practical option. These devices work with most hand tools, from hammers to grinders. Single-stage air compressors are lightweight and easy to move. However, two-stage air compressors provide more CFM, making them a better choice for industrial or commercial use. However, two-stage compressors are not suitable for private use. Therefore, if your main purpose is DIY and craft projects, it is better to choose a single-stage air compressor.
Compared with two-stage air compressors, single-stage screw air compressors are cheaper. They come from a variety of manufacturers and range in power from 3 to 600 horsepower. Single-stage air compressors are a cost-effective solution for a variety of air compressor needs. They offer flexibility and multiple control methods, making them an excellent choice for many different applications. Therefore, when choosing an air compressor for your business, choose the one with the most suitable functions.
Single-stage air compressors are the most affordable and easy-to-use air compressors for small to medium jobs. They also have higher compression ratios. The compression ratio is the ratio of absolute discharge pressure to absolute inlet pressure. When calculating the ratio, it takes into account atmospheric pressure and gauge pressure. The compression ratio pushes the surface area of ​​the rotor, which increases the thrust load.
Single-stage air compressors are smaller and easier to transport than two-stage units. Single-stage air compressors have one air intake, and two-stage air compressors have two air intakes. The difference between single-stage and two-stage air compressors largely depends on the number of times the air is compressed. A single-stage air compressor compresses the air once, while a dual-stage air compressor compresses the same amount of air twice.

low noise

Low noise air compressors are ideal for a variety of applications. While no air compressor is completely silent, some models are much quieter than others. For the Hitachi EC28M portable compressor, the noise level is 59 decibels. The compressor features steel rollers that protect the internal components and give it a sleek, modern look. It also has a one-gallon fuel tank and a half-horsepower drive.
Noise from air compressors can be distracting and reduce productivity. It is important to choose low-noise air compressors to keep employees healthy and happy at work. While noise is an unfortunate aspect of working on the shop floor, reducing it can improve productivity. By reducing distracting noise, employees can focus on their work and communicate more effectively. That means higher quality work and happier clients. If you’re looking for a low-noise air compressor, be sure to read the tips below.
Low noise air compressors are an excellent choice for businesses of all sizes. These powerful tools can run multiple tools simultaneously. The two water tanks are made of rust-resistant aluminum and are stackable. This air compressor is heavier and can handle large jobs with ease. It costs more than other air compressors, but it can handle a lot of work efficiently. CZPT Air Tools air compressors come with a one-year warranty and are highly recommended by contractors.
Noiseless air compressors are generally more expensive than comparable products, but they are worth the extra cost. Noiseless compressors are a good option for businesses that need to avoid disturbing nearby people. For example, you might want to consider a low-noise air compressor for a dental office, which cannot tolerate noise. Fortunately, this problem can be solved by relocating the compressor to a location that is more isolated from your workspace.
One brand of low-noise air compressors offers two models. The CZPT Air Tools 2010A features a large cast aluminum can, regulating pressure gauge, and two universal quick-connects. It produces 68 decibels of noise when it works. It has a large 8-gallon fuel tank capacity and has wheels and handles for easy transport. Its powerful engine produces a low noise level of 68 decibels.
Another popular low noise air compressor is the Makita MAC210Q Quiet Series. This model is capable of producing up to 71.5 decibels of sound, which is the amount of air it produces at 90PSI. The MAC210Q features a durable oil-free pump and weighs just 36 pounds with a handle and wheels. These compressors are easy to move and ideal for indoor work.