ClassX Video Lessons Youtube Channel The Engineering Mindset What's Inside A Filter Drier – How it works hvac
Welcome to an exploration of the inner workings of a hermetic filter drier, a crucial component in refrigeration systems. This article will guide you through its purpose, location, and internal structure, offering insights into how it contributes to the efficiency and longevity of HVAC systems.
A filter drier is an essential part of refrigeration systems, primarily installed in the liquid line between the condenser and the expansion valve. Its main function is to filter and dry the refrigerant, ensuring the system operates smoothly by removing moisture and contaminants that could harm components like compressors and valves.
Typically, filter driers are found in the liquid line of refrigeration systems. They are designed to handle high internal pressures and are often made from steel with a powder-coated surface to prevent corrosion. The direction of refrigerant flow is indicated by an arrow on the filter drier, although some models for heat pumps may allow bidirectional flow.
Upon cutting open a filter drier, the largest component visible is the solid core, which plays a pivotal role in the filtration process. This core is usually composed of 80% molecular sieve and 20% activated alumina. The molecular sieve captures larger dirt particles and retains moisture, while the activated alumina absorbs acids, protecting the system from corrosion and damage.
As refrigerant enters the filter drier, it surrounds the solid core. The system pressure pushes the refrigerant through the porous material of the core. A groove inside the core collects the refrigerant before it continues to the expansion valve. A screen at the end of the core captures smaller dirt particles, ensuring they do not circulate through the system. This screen can filter particles down to 25 microns with minimal pressure drop.
In summary, the filter drier is a vital component that ensures the refrigerant is free from moisture and contaminants, thus protecting the entire refrigeration system. By understanding its function and structure, you can appreciate its role in maintaining the efficiency and reliability of HVAC systems.
For those eager to delve deeper into the world of filter driers, Danfoss offers a range of free eLessons on their website. These resources provide comprehensive insights into the workings of filter driers and other HVAC components.
Continue your learning journey by exploring more educational content and resources available online. Stay informed and enhance your understanding of HVAC systems to ensure optimal performance and longevity.
Explore an interactive diagram of an HVAC system with a focus on the filter drier. Identify its location and trace the flow of refrigerant through the system. This will help you visualize the filter drier’s role and understand its importance in maintaining system efficiency.
Analyze a case study of an HVAC system failure due to a malfunctioning filter drier. Identify the causes and consequences of the failure, and propose solutions to prevent similar issues. This activity will enhance your problem-solving skills and deepen your understanding of the filter drier’s critical function.
Participate in a lab session where you will dissect a real filter drier. Examine its internal components, such as the solid core and screen, and discuss their roles in the filtration process. This hands-on experience will solidify your theoretical knowledge with practical insights.
Engage in a group discussion about the different types of filter driers and their applications in various HVAC systems. Prepare a presentation on your findings and share it with your peers. This collaborative activity will improve your communication skills and broaden your understanding of filter drier variations.
Complete a free eLesson on filter driers offered by Danfoss. This online resource will provide you with comprehensive insights into the design, function, and maintenance of filter driers, enhancing your knowledge and preparing you for real-world applications.
Sure! Here’s a sanitized version of the transcript:
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Hello everyone, Paul here from TheEngineeringMindset.com. In this video, we’re going to take a look inside a hermetic filter drier by Danfoss. We’ll discuss what they are used for, where we find them, and then we’ll cut one open to examine the components inside and their purposes.
If you’re still curious about filter driers by the end of this video, I recommend checking out Danfoss Learning for their collection of free eLessons. Danfoss is dedicated to sharing knowledge, and they’ve made hundreds of eLessons available for free on their website, including multiple courses on filter driers. You can find the link in the video description below.
So, where do we find these filter driers? This is a typical model, and they are usually installed in the liquid line of refrigeration systems, between the condenser and the expansion valve. We’ve previously covered how expansion valves, heat exchangers, and refrigerants work, so be sure to check those out as well. Links are in the video description.
On the side of the filter drier, there’s an arrow indicating the direction of refrigerant flow. Some models for heat pumps may be bidirectional, but in this case, we have a single-direction filter drier. The exterior features a powder-coated surface to prevent corrosion, and the black gloss finish gives it a premium appearance. The casing is made from steel to provide a strong structure, as it will be under high internal pressure once connected to the refrigeration system. Each end has solder connections, which can be either pure copper or copper-plated, depending on the model.
So, what is the purpose of a filter drier? These components are found in refrigeration systems, and as their name suggests, they filter and dry the refrigerant. They protect the system and its components by capturing and absorbing water particles, as well as harmful solid substances. This prevents these contaminants from circulating through the system and affecting the compressors, valves, sensors, and overall system performance.
Now, let’s cut it open and take a look inside. I’ll use a slit disc in the angle grinder to open it up, starting with a fresh disc for maximum cutting depth. I’ll secure the filter drier in the bench vise to keep it stable while cutting. As I mentioned, the casing is made of steel, so we’ll see some sparks, so it’s important to wear protective gear and move any flammable materials out of the way.
After making the cuts, we can remove the casing and see some key components inside. The largest component is the solid core, which we’ll examine shortly. At one end, there’s a large spring that helps keep the core in position inside the casing.
Next, we have the core, or molecular sieve. This model has a solid core composed of 80% molecular sieve and 20% activated alumina. The solid core acts as a filter to capture larger dirt particles and retains water, similar to a sponge. The aluminum oxide is included to capture and retain acids. Not all filter driers contain activated alumina; it depends on the application.
The refrigerant enters and surrounds the outside of the core. The system pressure forces the refrigerant through the porous material. Inside, there’s a groove where the refrigerant collects before continuing to the expansion valve. At the end of the solid core, there’s a screen that retains smaller dirt particles, capturing them down to 25 microns with minimal pressure drop. Following the screen is a perforated plate that keeps the internal parts in position while allowing refrigerant flow.
To summarize, the refrigerant enters through the inlet, passes across the spring, surrounds the solid core, and as it does, dirt, moisture, and acids are absorbed. It then collects in the groove, passes through the screen, and exits the unit, having been filtered and dried, before continuing to the expansion valve.
If you’re ready to learn more about filter driers, head over to the Danfoss Learning webpage and start your first course for free. Just follow the link in the video description below.
That’s it for this video! If you want to continue learning, click on one of the videos on screen now, and I’ll see you in the next lesson. Don’t forget to follow us on social media and visit TheEngineeringMindset.com.
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This version maintains the informative content while removing any informal language or unnecessary filler.
Filter – A device or process that removes impurities or unwanted elements from a fluid or gas. – Engineers designed a new filter to improve the air quality in the HVAC system by removing fine dust particles.
Drier – A component used to remove moisture from a system, particularly in refrigeration and air conditioning systems. – The drier in the refrigeration unit ensures that moisture does not freeze and block the flow of refrigerant.
Refrigerant – A substance used in a heat cycle to transfer heat from one area to another, commonly used in air conditioning and refrigeration systems. – The efficiency of the cooling system depends significantly on the type of refrigerant used.
Moisture – Water or other liquid diffused in a small quantity as vapor, within a solid, or condensed on a surface. – Excessive moisture in the air can lead to corrosion in metal components of the HVAC system.
Contaminants – Unwanted substances that may be present in a system, potentially causing harm or reducing efficiency. – The presence of contaminants in the hydraulic fluid can lead to system malfunctions and reduced performance.
Filtration – The process of removing particles from a fluid or gas by passing it through a filter medium. – Filtration is a critical step in ensuring the purity of the air circulated in cleanroom environments.
Pressure – The force exerted per unit area within a system, often measured in pascals or psi. – Maintaining the correct pressure in the pipeline is essential for the safe operation of the gas distribution system.
Core – The central or most important part of a system or component, often responsible for its primary function. – The core of the transformer is designed to efficiently transfer electrical energy between circuits.
Efficiency – The ratio of useful output to the total input in a system, often expressed as a percentage. – Improving the efficiency of the solar panels can significantly increase the energy output of the solar power system.
HVAC – Heating, Ventilation, and Air Conditioning; a system or technology used to provide thermal comfort and acceptable indoor air quality. – The new HVAC system installed in the building is designed to optimize energy use while maintaining a comfortable environment.
