Atlas Copco introduces solid desiccant compressed air-drying technology

Atlas Copco introduces CERADES, a solid desiccant created after years of R&D.


MM (Manufacturers’ Monthly): What is CERADES (pronounced as “seradas”)?

 AC (Atlas Copco): CERADES is the first-ever solid, ceramic desiccant. Until now, desiccant in air dryers has always consisted of loose beads made of activated alumina, molecular sieves or silica gel, being used in compressed air drying in lots of industries to have a certain quality dry air needed for applications.  CERADES desiccant dryer’s offers customers – significantly better compressed air quality, lowering pressure drops by up to 70 per cent, with improved energy efficiency, lower service costs, and improved environmental benefits.

MM: How long has this desiccant been in development? Who are the inventors/developers? 

AC: In 2016, after years of testing, Atlas Copco’s R&D team had its first breakthrough. Our new mission became bringing this idea to the market with benefits not found in a conventional desiccant dryer. We filed for the patent in 2018.

To create something outstanding like CERADES is a real breakthrough, and we are extremely proud to be able to deliver a product that is unique in the market and will bring many benefits to our customers.

MM: How does CERADES work?

AC: Simply put, as a structured desiccant – consisting of a solid, ceramic block – CERADES dries the compressed air as it flows through straight, structured tubes.

CD+ Cerades dryer

MM: How does CERADES differ from conventional desiccants?

AC: CERADES is the first-ever solid desiccant. Instead of simply improving traditional adsorption dryers, which use thousands of tiny, loose desiccant beads to dry compressed air, we devised a product that is superior and best explained through five key points:

  • First, lower energy costs. The compressed air flows straight through the structured CERADES, reducing the drop-in pressure of the dryer. In loose desiccant, the air must overcome more resistance as it pushes and weaves through the beads.
  • Second, the desiccant beads get pushed around through the drying tower during the cycle. This friction causes the beads to decay over time, which can compromise your dew point. CERADES lasts much longer to protect your air quality and extends service intervals.
  • Third, as loose desiccant decays, it releases a fine dust into your air system — which creates a requirement for extra filtration and maintenance, adding to service costs. This dust is also a health and environmental issue, as it circulates in the ambient air during desiccant replacement. CERADES eliminates this dust problem to give you environmental and health protection, lower operational costs, and reduced downtime.
  • Fourth, CERADES is vibration-resistant and can be mounted horizontally. This is very important for a number of applications, especially in the transportation industry – which can now enjoy trouble-free installation and continuous operation.
  • Finally, dryers with ceramic desiccant can handle a higher airflow. That means we can make them more compact.

MM: What are the benefits of using CERADES over dryers with conventional desiccants? How does purging compare between the ceramic and conventional materials?

 AC: When it comes to purging, whether a solid or bead desiccant, you want your purge rate to be between 15-20 per cent. CERADES hits this mark, achieving a rating as low as 16 per cent. Dew point ratings impact the efficiency of the purge, and dew point controls affect the airflow and amount of air being dried. With CERADES, if the customer is not using a PDP (pressure dew point) sensor, it will continuously dry the air to the required PDP, improving its efficiency. It maintains a constant dew point, alleviating decay over time, protecting air quality and extending the service intervals. Additionally, by maintaining a stable PDP, operators can save energy, reduce their carbon footprint and keep money in their wallets.  

As standard desiccants decay over time, it influences the PDP levels and impacts the efficiency. With CERADES, there is no desiccant decay. With no desiccant decay, CERADES is also environmentally friendly, providing clean compressed air and eliminating hazardous fine dust.

An inherent disadvantage of a standard desiccant is that it will lose its drying capacity when liquid water enters the dryer. This causes problems for the drying process and negatively affects air quality. CERADES overcomes this issue and will retain its drying capacity even when wet. That is an additional benefit that nobody else is offering. 

MM: Can this desiccant be used with existing dryers, or does new equipment need to be purchased? If so, what about the old existing dryers?

AC: To ensure the customer receives the full benefits of CERADES, we are only offering this technology in new equipment. Currently, our engineers are developing a plan to create a rebuild kit for bead dryers. When Atlas Copco launched its CD+ dryer range series in 2017, CERADES was already in the works, and we were prepared for the units to be replaced. The CD 20⁺-335⁺ is the first dryer to use the revolutionary CERADES.

MM: What is the expected life span of the CERADES material? How does the cost to replace it compare with that of conventional desiccants?

AC: CERADES desiccant lasts on average a minimum of two years longer than traditional desiccant, and under normal operating conditions you would only change CERADES desiccant every seven years. Changing a traditional loose desiccant in a dryer, due to the amount of dust particles, is a time-consuming health and environmental hazard, which is eliminated by CERADES.

MM: Is the technology available now in Australia?

AC: Yes. Atlas Copco’s new CERADES CD20-335+ (CD+) range of more than 30 models are the first dryers where the CERADES desiccant will be used. In addition to the benefits created by the incorporation of CERADES, the CD+ desiccant dryers are an extremely powerful, efficient, reliable, and quiet dryer which can operate continuously with 100 per cent airflow. The CD+ range offers a standard-pressure dew point of -40°C and customers can adjust the dew point to optimise the dryer performance for the needs of their specific applications.

MM: Why are existing manufacturers choosing CERADES?

AC:

  • Lower pressure drop, so it saves you money;
  • It has higher flow, so you can downsize and save money;
  • Smaller footprint, so you use less of your plant room;
  • No dust creation, so you save on extra filters;
  • No Decay of desiccant, so your staff are safer;
  • No Decay of desiccant, so the dryer performance is consistent;
  • Structured desiccant, so you have the flexibility to mount the dryer in any direction; and

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