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 and material handling needs, don’t hesitate to contact our engineering team at 440-543-7400 x 235 or by email at dc@dustcollectorhq.com. For all other inquiries, click here. 

Airlocks are required in order for dust collectors to operate correctly. When a dust collector is under positive pressure, the airlock prevents air and collected material from blowing out of the dust discharge flange. A lack of airlock will cause dust to be thrown into surrounding areas and pile up on the floor and other surfaces.

When a dust collector is under vacuum, an airlock prevents air from entering the dust collector from the dust discharge flange. If no airlock is installed, air will leak in through the dust discharge, re-entraining material from the hopper while lowering the airflow at the pickup points.

Which Type of Airlock You might Use

Every airlock will leak a certain amount of air into or out of the hopper depending on the conditions the hopper is under. Depending on your application, the amount of acceptable leakage might determine the type of airlock you use.

A knife gate has the greatest amount of leakage, because when the knife gate is open, there is no airlock, only when you close the knife gate will you achieve an airlock.

A rotary valve provides a good, steady airlock but in order for the rotor to turn, there must be a gap between the rotor and the housing. This gap allows air to constantly leak past the rotor. The rotary valve also will allow air pass if the pockets in the rotor are not fully filled with material.

The double dump valve provides one of the lowest leakage rates of an airlock. The double dump valve is similar to having two (2) knife gates in series. This creates a chamber between the two flap plates. At all times one of the flap plates is closed, so the total leakage in the double dump valve is the volume of the chamber minus the volume of the material in the chamber.

Aerodyne’s Vacu-Valve

Aerodyne also produces a Vacu-Valve, which provides low leakage. The Vacu-Valve can only be used on applications with a slight vacuum and must have material that is fine and free-flowing (doesn’t easily bridge). The Vacu-Valve has an opening that a rubber sleeve is attached to. This sleeve is pulled together by the vacuum in the hopper.

Material then begins to build up above the sleeve. As the material builds up, gravity and the weight of the material slowly trickles the material down through the sleeve and out of the system. This trickle action is dependent on many conditions, including the weight of the material, the amount of vacuum in the system, and the ease of the particles to flow through the sleeve (particle size, stickiness, etc.)

So when selecting an airlock for you dust collector, don’t forget to factor in the air leakage each airlock will allow.

For the full library of dust collection and material handling resources, including informational videos, case studies, test results, infographics, and more, visit the library tab on our website at www.dustcollectorhq.com.

To improve efficiency and safety, there is no substitute for an on-site inspection by an experienced expert. Click here to start the conversation about better dust collection and material handling practices. 

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.

Aerodyne now offers its pneumatic knife gate in a washdown design for flow control.  All parts are stainless steel or aluminum to prevent corrosion after washdown cleaning.  The washdown design has a cast aluminum body and stainless steel knife, support bracket, cover, pneumatic cylinder shaft and hardware, preventing corrosion after washdown cleaning. All these factors mean the StopTight Knife Gate can better handle streams of tough materials and solve more complex problems.

The design has proven effective and economical for companies already. For example, a US company that specializes in producing dough in the food industry needed a valve that would allow them to have control of the flow of ingredients into the tank. The valve needed to be made up of stainless steel and aluminum due to the difficult conditions of the tank. Looking for suggestions, the company contacted Aerodyne.

Aerodyne suggested the facility use the StopTight Knife Gate Valve in a washdown design as a flow control valve. The StopTight Knife Gate Valve can be used either in the line of flow or at the point of discharge. Using a linear motion, a blade advances until the passage is closed or it withdraws until the passage is open. In the closed position, the knife gate valve is designed to seal tightly. Aerodyne’s washdown pneumatic knife gate design effectively regulated the introduction of contents into the mixing tanks while adhering to food-grade specifications, helping the company to create dough and earn more dough.

Dan, understanding that the company had used a manual StopTight Knife Gate Valve in the past and was happy with the results, looked at the needs of the company and suggested that they use a 12” pneumatic Knife Gate valve with a position switch. The Knife Gate is an ideal solution to the company’s problems due to the fact that this product provides an effective way to control the flow of a variety of materials in differing operating conditions, either at the line of flow or the point of discharge. Furthermore, the Knife Gate sits tightly on a material handling system, which prevents loss of positive or negative pressure in the system, making it an ideal way to control discharge.

Furthermore, the Knife Gate Valve seals tightly on material handling systems, preventing the loss of positive or negative pressure within the dust collection system. This makes it an ideal solution for controlling material discharge while maintaining efficient dust control.

Aerodyne offers a wide selection of Knife Gate Valves designed to handle a variety of materials and operating conditions. From manual Knife Gate Valves to pneumatic Knife Gate Valves for dust control applications, Aerodyne has a solution for nearly every application. A variety of sizes are available, including industrial Knife Gate Valves for open hopper discharge or in-line use, with some models capable of closing through a static column of material.

A US company that specializes in producing dough in the food industry recently contact Aerodyne for a custom order. The company mixes all of its ingredients in a massive tank. They were looking for a valve that would allow them to have control of the flow of ingredients into the tank, but the valve needed to made up of food grade materials. Looking for suggestions, the company contacted Aerodyne.

Aerodyne suggested the facility use the StopTight Knife Gate Valve. This material handling valve is used as a flow control valve. It can be used either in the line of flow or at the point of discharge. Using a linear motion, a blade advances until the passage is closed or it withdraws until the passage is open. In the closed position, the knife gate valve is designed to seal tightly and prevent the loss of positive or negative pressure of the system. Aerodyne has a large selection of knife gate valves which can be used to handle a variety of materials and operating conditions.

There are very strict rules and regulations in the food industry that companies must follow. All of the equipment used in processing or handling the dough must be made of good grade materials. Aerodyne was able to fabricate a knife gate valve made of aluminum, stainless steel, and nylon to effectively control the introduction of contents into the mixing tanks as well as stay with in the regulations.

A bakery in IL was in need of material handling valves that would allow control of its baking materials. Specifically, the company needed something that would permit the addition of solids in to the baking process with ease and precision. After seeing a press release for Aerodyne’s StopTight Knife Gate Valve, the company reached out to Aerodyne for more information.

A knife gate valve is used as a flow control valve in a bulk-material handling system, either in the line of flow or at the point of discharge. Using a linear motion, a blade advances until the passage is closed, or it withdraws until the passage is open. In the closed position, the knife gate valve is designed to seat tightly and prevent the loss of positive or negative pressure of the system. Aerodyne has a large selection of Knife Gate Valves which can be used to handle a variety of materials and operating conditions. From manual valves to pneumatic valves for dust control, Aerodyne has a knife gate for almost any application.

Aerodyne suggested the company use three 12” pneumatic knife gate valves that have aluminum housing and a stainless steel blade for its operation.

To find out more about how the knife gate can help introduce control to your material handling process, click the photo below.

A knife gate valve is used to control flow in a bulk-material handling system, either in the line of flow or at the point of discharge. Using a linear motion, a blade advances until the passage is closed, or it withdraws until the passage is open. In the closed position, the knife gate valve is designed to seat tightly and prevent the loss of positive or negative pressure of the system. Aerodyne has a large selection of Knife Gate Valves which can be used to handle a variety of materials and operating conditions. From manual valves to pneumatic valves for dust control, Aerodyne has a knife gate for almost any application.

Since using Aerodyne’s StopTight Knife Gate Valve as part of its bagging process, the company has seen dramatic improvements in the operation. With the ability to control the flow of the fertilizer from the hopper, they have less of a mess to clean up and no longer have a loss of product. The company’s operation is now more efficient and easier for plant workers.

For more information on Aerodyne’s StopTight Knife Gate Valve click the in stock photo above. Or for immediate detailed brochures or a quote click the buttons below.