Dust Collection and Valves Blog

When to Use a Non-Powered Automatic Valve for Dust Discharge | Aerodyne

Posted by Tom Hobson on Jul 14, 2023 9:30:00 AM

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.

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Topics: rotary valves, airlocks valve, aerodyne vacu-valve

Top 5 Questions to Ask When Choosing a Material Handling Valve | Aerodyne

Posted by Tom Hobson on Mar 22, 2022 4:15:00 PM

Material handling valves come in all shapes, sizes, varieties, and with hundreds of available options. From rotary valves and knife gate valves to double dump valves and trickle valves the choices are nearly endless. With such a vast selection available, choosing the right material handling valve for a given application can be a difficult task and choosing the wrong valve can be costly.

While there may be more than one possible solution to a material handling need, there is often a best solution to be found if the proper considerations are given. Here are the top five questions any plant manager or plant engineer should ask when choosing a material handling valve.

  1. What is the nature of the material being handled?

The most important consideration for any material handling application is of course the material itself. The characteristics of the material being handled will determine what type of valve should be selected. Extremely fine material typically requires a valve with tight tolerances and seals to avoid material from dusting out to the atmosphere. Coarse or chunky materials often require a valve with larger clearances to avoid plugging or jamming of the valve mechanism.

  1. Will the valve meet your operational parameters?

Not all valves are created equally and the environments they are expected to operate in vary as well. In many cases material handling valves are put to use on systems with some degree of atmospheric pressure differential. Most material handling valves are intended to be airlocks as well; allowing solid material to pass through the system without allowing major pressure losses. Be sure to select a material handling valve that has a pressure rating within the range it will be expected to operate.

  1. How should the valve be powered?

All too often, plant maintenance personnel accept the “standard” valve control type listed by the manufacturer rather than choosing the best actuation method for the job. Pneumatic cylinders are the most widely used actuators for knife gate valves and many other process valves due to their continuous-duty rating and readily available shop air supplies. While pneumatic controls may appear to be an easy and convenient method to operate a knife gate valve, a manually operated unit may be more suitable and cost-effective for maintenance valves which are operated very infrequently.

  1. How easy is it to maintain?

Regular maintenance is a must for any material handling valve. As valve parts wear or material build-up occurs, the need for replacement, repair, and cleaning of the valve is inevitable. When choosing a material handling valve, close attention should be paid to how easily the valve will be to maintain. Quick-release access panels, change-in-place parts, and easily accessed wear parts all make the job of performing regular service on a valve much easier.

  1. How much will it cost?

While the initial investment for a material handling valve is important, it is only part of the equation. Frequent repairs or labor-intensive repairs to a valve can easily eat into any initial savings in cost. The cost of process downtime due to maintenance needs can become magnified if the valve cannot be repaired in place or replacement parts are not readily available.

Doing the proper due diligence also goes a long way in selecting the best material handling valve for a given application. Realistically, the success of a material handling valve comes down to the careful consideration of application parameters and how much time and effort is given to make sure the appropriate valve is selected.


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.

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Topics: material handling valves, double dump valve, airlocks valve

Air Leakage in Airlocks | Aerodyne

Posted by Tom Hobson on Dec 17, 2021 11:00:13 AM

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.


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.

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Topics: knife gate valve, vacu-valve, airlocks valve

Is Your Hygroscopic Dust Causing Issues in Your Dust Collectors?| Aerodyne

Posted by Tom Hobson on Mar 29, 2021 8:45:00 AM

Hygroscopic dust can really grow on your nerves! I know the marketing department might take away my writing duties after that line. But seriously, hygroscopic dust can cause major maintenance issues in your dust collectors. Hygroscopic dust captures water vapor and droplets. This causes the particles to grow in size and weight, thereby making them easier to capture and remove from the airstream. However, if you are using filters, that’s where the problems start.

Filters capture dust in between the filter fibers and on the filter cake. When the dust is hygroscopic this can lead to issues. Dust particles in the filter fibers can grow when exposed to water vapor. They can then not release when cleaned, blocking the air pathway, or if they do release during cleaning the filters could be left deformed, allowing particles through the filter.

When hygroscopic filter cake is exposed to water vapor, it can plug up the filter, preventing air from passing through. This prevents any dust collection from the needed areas because there is no airflow to pull the dust into the system. And during cleaning cycles, the filter cake is strongly adhering to the filter and won’t fall off.

To prevent this from being an issue you will need to identify where the water vapor is coming from.

Airlock

If humidity is leaking in from the airlock then a low leaking airlock would be needed. Rotary valves have a small space surrounding the rotor allowing it to rotate without locking up. This area constantly allows air to leak around. A double dump valve which uses two flaps in series to isolate the hopper or a rotary valve with wipers can cut down on air/humidity leakage into the hopper.

Housing holes

If there are holes in the housing, high humidity outside air can leak in. Replacing or patching the holes will prevent air leakage. If corrosion is an issue, changing materials of construction or coating the hopper might help prevent future issues.

High water content in the compressed air used for cleaning

Install water traps and filters to keep the compressed air used for filter cleaning with low humidity. Often times this can cause greater issues than leaking airlocks or hoppers because the high pressure air goes through the filter, expanding the filter to shake off the dust. This delivers the humidity to the dust collected in the filter, which could cause greater pluggage.

High humidity air coming in with the dust

Installing a pre-filter will remove the majority of the larger heavier particles before they can see the filters. This minimizes the amount of material the filters contact, extending their life. Pre-filters such as cyclones and dropout boxes can often provide additional help on issues above and even extend the life of filters caused by high dust loading.

So when you have hygroscopic dust and your filters are plugging up too fast, try to isolate the area where humidity is coming.


 

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.

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Topics: dust collector, vacu-valve, airlocks valve, GPC Cyclone, arirflow, hygroscopic dust

Why Are Airlocks Needed? | Aerodyne

Posted by Tom Hobson on Dec 16, 2020 10:00:00 AM

All dry dust collectors have a hopper which temporarily collects the dust while it is moved out of the system. The hopper usually has a flanged outlet on bottom which allows the dust to fall outside of the dust collector vessel. When you are deciding what to put under the hopper it is important to make sure that air doesn’t flow out of or into the opening while still allowing the dust to empty from the hopper. An airlock (discharge valve) is used to prevent this.

An airlock comes in a variety of designs. The most common is the rotary airlock while the simplest design is a trickle valve (Aerodyne Vacu-Valve). What these valves do is prevent the higher pressure air from going to the lower pressure air. Generally dust collectors are designed to be under vacuum. This prevents dust from escaping the vessel and helps protect the exhaust fan from being damaged by dust loading. However, some systems do have pressured dust collectors for operational reasons. Either way it is important that there be some kind of airlock under the hopper.

Dust Collector Under Pressure

A pressurized dust collector will blow air out of the hopper if no airlock is installed on the hopper. This will create a dust cloud around the dust collector. If indoors this will coat the surrounding equipment and become a nuisance to employees in the area. Plus it’s pretty unseemly having a dust collector spewing dust out in a facility.

Dust Collectors Under Vacuum

A system under vacuum, however, is much more impacted by not having an airlock. The airlock prevents outside air from entering the system. So if you don’t have an airlock the exhaust fan will begin pulling air into the system through the hopper. This does two main things. For one, it lowers the airflow at the pickup points that are collecting the dust. Air will flow the easiest path (much like water). So if you have an opening allowing air to enter through the hopper then air will take advantage of this. And since your exhaust fan doesn’t care where the air comes from it will pull much of the air through the hopper. This airflow means that there will be less air coming from the pickup points. This could cause insufficient dust pickup at those points and even dust buildup in the ductwork. The second issue is that any dust collected in the hopper could get re-entrained by the air entering through the hopper outlet and then leave the dust collector. This will decrease the system removal efficiency and could cause violations of permits, increased fan maintenance, etc.

So when you are operating a dust collection system, make sure that the dust discharge flange is installed with an airlock, that way you will have the system operating at its peak efficiency.


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.

Free Consultation

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Topics: vacu-valve, airlocks valve, GPC Cyclone, arirflow

5 Signs You Need A Checkup On Your Dust Collection System | Aerodyne

Posted by Tom Hobson on Jun 25, 2020 2:37:29 PM

Dust collectors are required in facilities for multiple reasons. After installation, they are often forgotten about until something isn’t working right.  In order to fix the problem, the system has to be almost re-engineered to figure out what the design originally was. The following things are signs your dust collector isn’t working how it was designed and you need to perform a checkup.

1. Area around the air inlets are dusty

The dust collector inlets/hoods capture the dust from your process. If you are noticing greater dust in those areas, then your dust collector isn’t operating correctly or something changed in the process. Either way, having an expert come in and look at the system is your 1st step to solving the issue.

2. High pressure drop through the dust collector

Baghouses and cartridge collectors use filters to capture the dust. They are cleaned regularly to prevent dust buildup, but they will plug over time. Once the dust builds up, less air will be pulled through system thereby allowing more dust to escape. You might not notice this change at the hoods, but the pressure gages across the filters will tell you when the pressure drop is high.

3. Material collected in the dust collector is less than before

As less air is being pulled into the system, more dust is escaping the system, which means less dust is being collected by the dust collector. One way of noticing this is when you’re not hauling away the dust from the hopper as much. An example would be normally you are replacing the 55 gallon drum once per week but now it’s once every two weeks.

4. Equipment in the area requires high maintenance

Dust can coat equipment and get into crevices. This can cause increased wear on rotating equipment, contaminate fluids, and plug air filters. All of these can cause an increase in equipment break downs. Equipment that is wearing down usually isn’t operating at its highest efficiency, thereby needing more energy. So if you are noticing an increase in equipment maintenance in a specific area, the dust collector might not be working as it should.

5. Workers are complaining about dusty areas or are calling off work more often

Dusty air can cause issues with the workers in the area. Dust can cause inflammations in the respiratory system which can cause people to be more susceptible to sickness. Workers might complain about the dusty air or just get sick more often.

Usually, combinations of these signs are happening at the same time. However, some might be more noticeable than others. So if you are seeing one of these signs, check for the others and then schedule a dust collector evaluation to get your system back into working order.


Bridging Dust?

Try the Aerodyne Mighty Whopper.

Aerodyne’s Mighty Whopper rotary valve has over-sized rectangular inlet and outlet. 

Download Brochure

 


5 Signs Your Dust Collection System Needs Maintenance

Is your dust collection system working at peak efficiency? A quick, do-it-yourself examination may identify symptoms that your system needs a check-up.

Watch Video


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

Read More

Topics: dust collector, airlocks valve, compact cyclones, Rectangular airlocks, Mighty Whopper

Why are Lower Cyclone Pressure Drops Not Always Better than Higher Pressure Drops? | Aerodyne

Posted by Tom Hobson on May 29, 2020 2:30:00 PM

When designing a dust collection system, the static pressure required of the system is extremely important.  The reason is because the exhaust fan must be able to pull the design airflow at the design static pressure in order to get the design performance.  Usually the higher the static pressure is the greater power is required by the fan at a constant airflow.  This means, dust collector system designers usually try to keep the total static pressure low, in order to go with a smaller fan that costs less to operate.

Cyclones Pressure Drop

However, when it comes to cyclones, this is not always the best policy.  A cyclones pressure drop is based on the amount of air going through it.  So a 24” diameter cyclone might have a 3” pressure drop at 1500 CFM and a 5.5” pressure drop at 2000 CFM.  So a smaller cyclone can handle a higher airflow at a higher pressure drop.  This would lower the fabrication cost of the cyclone, and allow it to fit in a more confine space, but have a higher operational cost (more HP required).

Higher Pressure Drop

But using a smaller cyclone also has another benefit, the higher your pressure drop, the more efficient the cyclone will be.  This increase in removal efficiency usually will not allow you to use a cyclone only for dust control, but it will help remove smaller particulate before your primary filter.  This will allow you to capture more material before contamination, lower the loading on your filters, and decrease utility usage (water or plant air).

So when you are designing a dust collection system, don’t look for the cyclone with the lowest pressure drop, but look at all the aspects that affect the system.  Will a smaller cyclone fit better?  Will higher removal efficiency in the cyclone be beneficial to the main dust collector?


How the Aerodyne SplitStream Cyclone Works

The SplitStream Cyclone Collector is designed for dust collection systems where tough dust like abrasive, sticky, fibrous, hygroscopic or granular persist. Configured horizontally or vertically, the cyclone’s low-profile design is perfect for mounting in space-restricted areas.

Watch Video


5 Signs Your Dust Collection System Needs Maintenance

Is your dust collection system working at peak efficiency? A quick, do-it-yourself examination may identify symptoms that your system needs a check-up.

Watch Video

 


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

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Topics: dust collector, airlocks valve, compact cyclones, Rectangular airlocks, Mighty Whopper

Dust Collection System: Confined Space Entry | Aerodyne

Posted by Tom Hobson on Dec 10, 2019 9:30:00 AM

 

Cyclone maintenance can often be difficult.  Traditional vertical cyclones are tall with long sloping hoppers making access for maintenance limited. Additionally, confined workspace can require special hardware to clean. Smaller versions can be disassembled but may require the unit to be disconnected from the airlock and duct work for cleaning procedures.

 

 

OSHA Special Procedures Requirement                                           

OSHA requires companies to have special procedures for “confined space entry”.  Equipment that is large enough for an employee to enter fully and is not designed for continuous occupancy and has limited or restricted means of entry or exit is considered confined space.  If a person has to go inside, they often require a “permit to enter”.  This could include having a dedicated person outside.  While if the worker only needs to reach inside, the requirements may not require as stringent precaution or possibly even a permit. 

Horizontal Cyclones – Removable Backplate

However, horizontal cyclones (as manufactured by Aerodyne Environmental) have a removable backplate.  This allows access to the cyclone internals without disassembly and disconnecting of the cyclone.  Small and medium size units also allow access without having to fully go inside the cyclone.  Many units are small enough that normal humans can’t even fully enter.  So full confined space entry procedure may not be required.  The company’s confined space entry policy should be review to see what is required.


GPC Dust Collector Spec Request

The GPC Dust Collector is an efficient way to handle your dust collecting needs.

 

Download Specification

 


Dust Collection Deathmatch: Baghouse vs. Cartridge

Trying to decide whether to use a cartridge collector or baghouse in your dust collection system? Find out the four factors that separate the baghouses and dust cartridges.

Watch Video


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

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Topics: dust collector, airlocks valve, horizontal cyclone, compact cyclones, confined space

Rectangular Airlocks: The Better Rotary Valves | Aerodyne

Posted by Tom Hobson on Nov 25, 2019 10:15:00 AM

Dust collectors can have issues with material bridging in the hopper. 

Round or Square Airlocks

A standard collector uses round or square flanged airlocks instead of a rectangular design better suited where bridging persists.These designs are great for standard dust that doesn’t bridge.  They are easy to fabricate, thereby keeping cost low.  However, the uniform dimensions of the flange allow the dust to be equally supported on all sides, creating a more stable environment for a dust bridge to form.  One way to counteract this is by over-sizing your airlock. An example would be using a 12” rotary valve instead of an 8” valves.  While oversizing the airlock lowers the chance of bridge forming.  A bridge can still form due to shape of the flange. 

Better Airlocks: Rectangular Rotary Valve

A better way would be to use a rectangular rotary valve.  Since the rotary valve has a rectangular flange, dust trying to bridge over the opening isn’t equally supported.  And any bridge trying to form across the long axis will be unstable and begin to bow down into the valve opening, where the rotors will grab them and destroy the bridge, allowing the free flow of dust out of the hopper.


Bridging Dust?

Try the Aerodyne Mighty Whopper.

Aerodyne’s Mighty Whopper rotary valve has over-sized rectangular inlet and outlet. 

Download Brochure

 


5 Signs Your Dust Collection System Needs Maintenance

Is your dust collection system working at peak efficiency? A quick, do-it-yourself examination may identify symptoms that your system needs a check-up.

Watch Video


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

Read More

Topics: dust collector, airlocks valve, compact cyclones, Rectangular airlocks, Mighty Whopper

Aerodyne Vacu-Valve ® vs. Traditional Rotary Valve | Aerodyne

Posted by Tom Hobson on Sep 30, 2019 2:15:00 PM

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.

Vacu-Valve is a Simpler Solution

 


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.

Free Consultation

Read More

Topics: dust collector, rotary valves, trickle valve, airlocks, airlocks valve, aerodyne vacu-valve

Aerodyne Environmental: Home of the Horizontal Cyclone and  Vacu-Valve® Airlock Valve

Inspired To Be Different.

At Aerodyne, we choose to take a different approach to collecting dust and handling materials. Our cyclones are unique in design to address common issues such as problematic dusts and space constraints. Our airlocks are chosen to fit your specific application instead of hastily installing traditional equipment options. We believe that when we see things differently, we can solve problems effectively. That's why so many people turn to us for help in solving their tough dust problems.

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