Selecting the appropriate airlock for your dust collection system is crucial for ensuring optimal performance and efficiency. While the rotary valve is a common choice, exploring alternative airlock options can lead to better results tailored to your specific application needs. In this article, we'll delve deeper into the various airlock alternatives available, highlighting their features, benefits, and suitability for different scenarios.

Rotary Valve

The rotary valve is a staple in many dust collection systems, particularly when handling combustible dust. Its robust construction and reliable operation make it well-suited for a wide range of applications. However, the downside of constant air leakage across the valve can impact system efficiency and contribute to maintenance challenges over time.

Double Dump Valve

For applications where minimizing air leakage is paramount, the double dump valve emerges as a viable solution. This airlock excels in handling large, bulky materials and offers enhanced performance in scenarios where material wrapping around the rotary valve rotor is a concern. By reducing air leakage, it ensures more efficient dust collection and helps maintain air quality standards.

Trickle Valve

Cost-effective and easy to maintain, the trickle valve is an attractive option for operations seeking simplicity and affordability. Operating with a vacuum and suitable for fine, free-flowing particles, it provides efficient material discharge while requiring minimal upkeep. Its low cost of ownership and straightforward operation make it a popular choice for many applications.

Knife Gates

Designed for periodic emptying of dust collector hoppers, knife gates offer versatility in design and functionality. Available in various configurations, including knife gate, slide gate, and orifice type, they provide flexibility to accommodate different application requirements. However, it's essential to consider their sealing capabilities and potential airlock loss when open to ensure compatibility with specific operational needs.

Direct Coupling to a Hopper

Simple and straightforward, direct coupling to a hopper is suitable for low dust loading situations. While it offers ease of operation, it may require the dust collector to be turned off during hopper changes, impacting overall system uptime. Additionally, precautions must be taken in combustible dust applications to address safety concerns associated with the lower hopper.

Expanding your understanding of airlock options beyond the rotary valve can lead to significant improvements in dust collection system performance. By considering factors such as material characteristics, air leakage concerns, and maintenance requirements, you can select the most suitable airlock for your specific application. This informed decision-making process not only enhances operational efficiency but also contributes to cost-effectiveness and long-term sustainability.

For expert guidance in selecting the right airlock for your dust collection needs, don't hesitate to contact Aerodyne at 440-543-7400 or dc@dustcollectorhq.com. Their team is dedicated to helping you address your dust collection challenges effectively and efficiently.

To improve efficiency and safety, there is no substitute for an on-site inspection by an experienced expert. Click below to start with a free 20-minute phone consultation by clicking the button.

Look under almost any dust collector and you will see a rotary airlock valve spinning its rotor and emptying the collected contents from the hopper. These valves have long been used to maintain a seal in vacuum dust collection systems while simultaneously providing an escape route for the dust. 

The advantages of a rotary airlock for dust collectors include automatic hopper emptying, minimal vacuum pressure loss, and the many options available to meet specific application needs. Rotary valves can be custom fit to handle high temperatures, harsh chemical environments, and abrasive materials. Rotary valves do, however, have a few major drawbacks.

Rotary Airlocks Drawbacks

Because rotary airlocks are sealed tight to the atmosphere they can be very difficult to clean. Cleaning a rotary valve often involves removing the drive assembly, end plate, and finally the rotor. This process can take hours to perform. Rotary valves are also expensive to operate. Typically, these valves are left running continuously, even when there is no dust present in the hopper. This not only wastes electricity but puts undue wear on the valve. Repair and replacement parts for rotary airlock valves can be quite costly as well. Even with these shortcomings, the rotary airlock remains the industry standard for most dust discharge applications.

Non-Powered Automatic Dust Discharge Valve

One alternative which has been gaining popularity is a non-powered automatic dust discharge valve. These valves, like the Armadillo and Platypus Vacu-Valves from Aerodyne, rely on the negative pressure (max -18″ W.C.) of a dust collector to hold a rubber sleeve closed to maintain an airlock. As the weight of the dust in the hopper builds up, the sleeve is forced open and dust is discharged from the valve. Leaf springs inserted into the valves sleeve also help to counterbalance the vacuum. 

The valves are available with a variety of sleeve materials for different applications. While these valves cannot be used in every dust collection system they are a very economical alternative to expensive rotary valves.

The Vacu-Valves from Aerodyne are priced at a fraction of the cost of standard rotary airlock valves and require no electricity to operate. These valves have no controls and require no lubrication. They easily handle abrasive materials that would jam or wear out a rotary valve.

To improve efficiency and safety, there is no substitute for an on-site inspection by an experienced expert. Click below to start with a free 20-minute phone consultation by clicking the button.

Do the rotary valves under your dust collectors cause maintenance headaches?  Are they clogging?  Are you having to drop everything and assign extra labor to fix them?

The disadvantages of Rotary Valve

Most dust collectors are equipped with a motor-driven rotary airlock valve that empties contents from the hoppers. Rotary valves have been used for many years and are probably the most widely used airlock design. However, maintaining rotary valves is difficult and time consuming. These valves run continuously, regardless if dust is present, which leads to wasted electricity. In addition, the valves can wear out rapidly, resulting in costly repairs and replacements.

Best Alternative: Aerodyne Vacu-Valve ^®

A highly cost-effective alternative is Aerodyne’s Vacu-Valve ^®  Trickle Valve System. The Vacu-Valve relies on the negative pressure of the material handling system to hold the duckbill sleeve closed. As the dust or material builds up, the sleeve is forced open, allowing the contents to discharge. Once emptied, the negative pressure then immediately closes the duckbill again. This trickle valve system requires no lubrication, power, or controls. Materials that would normally jam or wear out a rotary airlock valve, the Vacu-Valve handles with ease. There is a variety of duckbill sleeve options designed for specific applications; and the Aerodyne Vacu-Valve ^® is available in an open or closed design, to further accommodate the particular application.

Aerodyne’s Vacu-Valve ^® is the solution! Have a look at this infographic and to learn how the Vacu-valve solves these issues and improves the discharge efficiency of your baghouse, filters and cyclones.

How Do Vacu-Valve Dust Valves Work?

To learn more about which dust collector, please contact our experts at 440-543-7400 or visit our website: www.dustcollectorhq.com.

To improve efficiency and safety, there is no substitute for an on-site inspection by an experienced expert. Click below to start with a free 20-minute phone consultation by clicking the button.

Look under almost any dust collector and you will see a rotary airlock valve spinning its rotor and emptying the collected contents from the hopper. These valves have long been used to maintain a seal in vacuum dust collection systems while simultaneously providing an escape route for the dust. The advantages of a rotary airlock for dust collectors include, automatic hopper emptying, minimal vacuum pressure loss, and the many options available to meet specific application needs. Rotary valves can be custom fit to handle high temperatures, harsh chemical environments, and abrasive materials. Rotary valves do however, have a few major drawbacks.

Because rotary airlocks are sealed tight to the atmosphere they can be very difficult to clean. Cleaning a rotary valve often involves removing the drive assembly, end plate, and finally the rotor. This process can take hours to perform. Rotary valves are also expensive to operate. Typically, these valves are left running continuously, even when there is no dust present in the hopper. This not only wastes electricity but puts undo wear on the valve. Repair and replacement parts for rotary airlock valves can be quite costly as well. Even with these shortcomings, the rotary airlock remains the industry standard for most dust discharge applications.

One alternative which has been gaining popularity is a non-powered automatic dust discharge valve. These valves, like the Armadillo and Platypus Vacu-Valves from Aerodyne, rely on the negative pressure (max -18" W.C.) of a dust collector to hold a rubber sleeve closed to maintain an airlock. As the weight of the dust in the hopper builds up, the sleeve is forced open and dust is discharged from the valve. Leaf springs inserted into the valves sleeve also help to counterbalance the vacuum. A video demonstration of how this works is available here. The valves are available with a variety of sleeve materials for different applications. While these valves can not be used in every dust collection system they are a very economical alternative to expensive rotary valves.

The Vacu-Valves from Aerodyne are priced at a fraction of the cost of standard rotary airlock valves and require no electricity to operate. These valves have no controls and require no lubrication. They easily handle abrasive materials that would jam or wear out a rotary valve.

To learn more about which dust collector valve is right for you, please contact our experts at 440-543-7400 or click on the button below to get our infographic, Vacu-Valve is a Simpler Solution.

When you are specifying your dust collector, don’t just settle on a rotary valve.  There are other airlocks that might be better suited for your application.  Other airlocks include the double dump (flap) valve, trickle valve, and knife gate.  Not to mention just bypassing an airlock totally and connecting a hopper directly to the bottom of the dust collector.

The following will help you figure out which is the best solution:

1. Rotary valve – Use this if you have combustible dust. However, you will have constant air leakage across the valve.
2. Double dump valve – Use this if you want to minimize air leakage. The Double Dump works great with big, chunky material or if you’re worried the material may wrap around a rotary valve rotor.
3. Trickle valve – Use to save money and time. Requires a vacuum and usually a fine, free-flowing particle to work effectively.  It’s low cost and easy maintenance makes it very attractive when suitable.
4. Knife Gates – Used for periodic emptying of the dust collector hopper into another container. Knife gates come in a variety of design (knife gate, slide gate, orifice type, etc.).  Depending on the design, they can provide an airtight seal or not.  However when open, the airlock is lost.
5. Direct couple to a hopper – Used with low dust loading and could require the dust collector to be turned off during changing of the hopper. Also be-careful to take into account the lower hopper when used on a combustible dust application.

When you are looking for an airlock, don’t just automatically use a rotary valve.  Doing so may cause operational and maintenance issues in the future.  It could also cost you more money.  If you would like help in picking the best airlock, don’t hesitate to contact Aerodyne at 440-543-7400 or dc@dustcollectorhq.com. He is available to help you to solve your dust collection issues.

When you have a combustible dust, not only does your dust collector require to be protected against a deflagration, but the airlock must contain the event.  NFPA-69 allows the use of a rotary valve as long as the following:

1. Deflagration isolation by flame quenching (close-clearance valves) or
2. Deflagration isolation by material blocking (product layer above the valve)

Most rotary valves use flame quenching to achieve compliance with the spec.  Basically this requires the valve to have a clearance to the housing no greater than 0.2 mm and have at least six vanes, so that two vanes are isolating the event at all times.

Many rotary valves manufacturers comply with these specifications.  When you are looking at a rotary valve for you combustible dust application, remember to confirm that the valve complies with NFPA-69. 

If you are having operational issues on your dust collection system, contact Aerodyne at 440-543-7400 or dc@dustcollectorhq.com.  He is available to help you problem solve your dust collection issues.