Posted by Control Concepts USA on | Comments Off on What Causes Material Bridging in Hoppers and How AirSweep Can Help
Material bridging in a hopper can slow down production and reduce bulk storage space. The stagnant material can spoil or become contaminated, and workers have to clear the vessel and throw out compromised batches.
What is material bridging?
Bridging is the material block that forms above the discharge outlet of a hopper, silo, or any bulk material handling equipment.
The bridge is caused by friction on the vessel walls which slows down the flow of material. Eventually, the material particles start to bind and interlock, until it partially or completely blocks the discharge outlet.
The bridge is so strong that it can support the weight of material above it. New material can condense the trapped material further and strengthen the bonds.
Types of material bridging
Mechanical bridging. Particles mechanically interlock, like jigsaw puzzles. This usually happens for particles that are larger than 3mm.
Cohesive bridging. Particles compress until they bind together. This usually happens for smaller particles, especially those that attract moisture.
What causes material bridging in the hopper?
Material bridging can be caused by the hopper design, the material’s flow properties, and the conditions in the plant.
Hopper Design
Ideally, the hopper design should reduce friction and encourage flow. However, there is no one-size-fits-all solution. Solids and liquids behave differently, and materials have unique properties that can also vary in different conditions. These factors have to be considered while choosing the hopper’s angle, and the outlet’s shape and diameter.
Material Properties
Some materials are simply more prone to bridging and arching. This includes:
Moist and sticky materials
Materials that tend to settle during storage
Materials with a high cohesive strength
Hygroscopic powders that attract moisture
Pellets that soften and form soft clumps
Fibers that can entangle
Irregular particles that can interlock
Heavy materials that can push down on stagnant material and cause it to compress
Plant Conditions
Fluctuating temperatures can affect the stress on the hopper walls and the material flow properties. Moisture in the air can cause materials to expand and compress. Gas in the air can also permeate through powders and fill empty spaces.
The best solution for material bridging in the hopper
Flow aids solve bridging and other material blocks by breaking up the cohesive bonds in the material. However, not all flow aids can do this safely or effectively.
Manual cleaning—where workers hammer the vessel or enter the hopper to clear the build-up with axes and shovels—is slow and dangerous. Some materials release flammable or toxic gases during storage. Workers are also at risk for falls, sprains, health problems from direct exposure to the material, or being hit by falling material.
Vibrators can damage the vessel and can cause some materials to become more compact. Fluidizers can only activate light powders; air cannons are expensive and still leave material residue on walls.
AirSweep is the most cost-effective solution for material bridging in hoppers. It releases powerful air pulses that break up bridging and sweep stagnant material back into the flow stream.
AirSweep engineers customize the system so the units are installed at key areas on the hopper to stimulate first-in/first-out flow. They select the right model for the material and the vessel size. The AirSweep USDA-accepted model is also specially designed for sanitary applications like food, beverage, and pharmaceuticals.
The AirSweep system is energy-efficient. It uses less air than air cannons, and the units pulse in sequence instead of running continuously like vibrators and fluidizers. The units also have a large area of activation and move more material with every pulse.
Posted by Control Concepts USA on | Comments Off on Solve Common Problems When Handling Bulk Materials
Every industry uses dry bulk materials—whether it be chemical powders, pellets, flakes, mined minerals, raw materials, food, additives, stabilizers, or preservatives.
Each of these materials has its own properties that can affect how they behave while being stored, transported, or processed. And when you’re dealing with tons of materials, the stakes become higher. Any problems will incur huge delays and costs.
Bulk material handling (BMH) equipment can help prevent dry bulk materials handling issues, and improve production efficiency. The right equipment can even help lower costs, and increase plant safety.
Control Concepts, Inc.: Your Partner in Bulk Material Handling
Since 1951, we have helped companies resolve dry bulk materials handling issues. The patented technologies are used in every industry: mining, cement, food, pharmaceuticals, chemicals, mined minerals, and more.
We offer three products for bulk material handling: AirSweep pneumatic flow aids, DAZIC zero speed switches, and AcoustiClean sonic horns. Each of them addresses particular dry bulk materials handling issues to prevent delays, unnecessary costs, and safety risks.
AirSweep for on-demand material flow
Poor material flow is one of the most common dry bulk materials handling issues—and the most problematic. Sluggish flow (or even no flow) can:
Slow down production
Compromise batch consistency
Cause contamination and spoilage
Lower vessel capacity
Increase material waste
Create flammable environments
AirSweep uses powerful air pulses that break up material blocks and sweep stagnant material back into the flow stream. Unlike other flow aids like vibrators and air cannons (or the old-fashioned method of hitting the vessel with a hammer), it does not cause metal fatigue.
AirSweep has been proven effective for all types of dry bulk materials, including damp powders, plastic flakes, fibers like tobacco, pellets, and irregular particles like mined materials. It also has lower energy and maintenance costs than other flow aids, and can easily be removed from the vessel for cleaning with simple tools.
DAZIC zero speed switch to prevent material pileup
If a conveyor belt or bucket elevator fails, tons of material can spill over and pile up. Workers will need days to clean it up, and companies will need to face production losses and additional manpower costs.
Spilled material can also create safety risks, especially if it is heavy, flammable, or classified as a toxic chemical. That is why OSHA and other safety organizations require plants to take precautionary measures for machine failure and spills.
DAZIC zero speed switches are very affordable but can prevent very expensive and dangerous material pileups. They are attached to equipment to detect any abnormal change in rotation speed. If the equipment speeds up, slows down, or stops completely, DAZIC sends a signal to the operator to shut it down.
DAZIC can be attached to any bulk material handling equipment with a rotating shaft, such as
Rotary valves
Bucket elevators
Belt, drag, and screw conveyors
Fans
Blowers
Saw blades
Drive motors
Mixers
Crushers
Agitators
Rolling mills
AcoustiClean Sonic Horns to clear light material buildup
Light powders can accumulate on surfaces and hard-to-reach areas. This can cause contamination issues, affect the efficiency of the vessel, or create potentially flammable environments.
AcoustiClean Sonic Horns produce high-energy, low-frequency sound vibrations that disperse dry material. Compressed air is applied to a sound generator, which vibrates a titanium diaphragm. The sound waves clear the material, to clean your material handling equipment.
AcoustiClean can be integrated into the system to automatically clean the surface between production runs. It reduces plant shutdowns, prevents cross-contamination during production, replaces dangerous and expensive manual cleaning, and improves energy/heat transfer efficiency and lifespan of machines.
Bulk Material Handling Solutions
AirSweep, DAZIC, and AcoustiClean can prevent many dry bulk materials handling issues. For more information, or to get a customized quote contact us.
Posted by Control Concepts USA on | Comments Off on AirSweep Solves Biggest Bulk Material Processing Challenges
Reliable material flow is critical for efficient bulk material processing. Material blocks slow down production and waste time and money. Stagnant material can also be contaminated or affect batch consistency.
So, the biggest challenge of bulk material processing is to achieve on-demand, first-in/first-out material flow. Unfortunately, that is easier said than done.
Why is it hard to achieve reliable material flow?
There is no single, simple formula for achieving good material flow. You have to consider many factors, some of which cannot be controlled or changed.
Some materials have problematic flow patterns, because of their chemical or molecular structure, weight, and how they react to moisture.
Cohesive and adhesive force, which cause particles to stick together and block the discharge
Cohesive strength and internal friction affect how strong the material block is
Bulk density, which affects how easily it flows because of gravity
Particle size and shape
Tendency to absorb moisture
Angle of repose, which is directly related to the flow rate
Flow patterns are difficult to predict. Product formulas will include a variety of materials, which all have their own particle characteristics and densities. If a company decides to change its formula it can encounter a material flow problem.
Some vessels are not designed for efficient material flow. The slope or angle of the vessel and the size and shape of the discharge outlet can affect the rate of flow. Unfortunately, not all equipment is customized for the flow properties of the materials.
Plant humidity and moisture can affect materials. This is especially true for countries with high humidity or materials that are hygroscopic or have a tendency to attract moisture.
Material flow problems can occur at any stage of bulk material processing. Some materials can settle and become compact during storage, while others will flow well until it is mixed with other materials.
What are the most common material flow problems?
The most common bulk material processing problems are bridging, ratholing, and segregation.
Bridging occurs when material forms a large arch above the vessel discharge and stops the material flow. It can be caused by large particles interlocking, or smaller particles bonding together because of the moisture, temperature, particle shape, or concentration of fines.
Ratholing occurs when stagnant material builds up on the vessel walls and thus restricting the passage of materials. Aside from slowing down the flow, it also causes material waste and possible contamination.
Segregation is the uneven distribution of components of bulk material because of differences in their physical or chemical properties. This can lead to inconsistent formulas, which can affect product quality and safety.
What can improve material for bulk material processing?
AirSweep eliminates bridging, ratholing, material segregation, and other flow problems. It guarantees on-demand, first in/first out flow, and has lower energy and maintenance costs than other flow aids.
Posted by Control Concepts USA on | Comments Off on Benefits of AcoustiClean Sonic Horns
AcoustiClean Sonic Horns provide several material flow benefits that plant managers need. AcoustiClean Sonic Horns produce high-energy, low-frequency sound vibrations that disperse dry material. It can help clean vessels and equipment like silos, hoppers, heaters, and fans to minimize downtime and material build-up.
Sonic horns are often used in industries like cement, petrochemical, and power generation. However, it can benefit any process where material build-up can occur.
AcoustiClean reaches blind spots
Manual cleaning can be tedious, time-consuming, or even impossible in inaccessible areas. AcoustiClean’s powerful sound vibrations can clear out material in seconds, even in equipment that is hard to clean (i.e, pipes or baghouses) or are in hard-to-reach locations. It can also reach blind spots that mechanical soot blowers and rapping systems often miss.
No equipment damage
Unlike other cleaning systems that use pressurized air, sound vibrations don’t damage sensitive equipment like tubes.
Customizable for different environments
AcoustiClean can be made of either stainless steel or cast iron. Stainless steel can be sanitized easily and is suitable for food and sanitary applications. Cast iron can withstand temperatures up to 2000ºF.
A manufacturer of building materials sends waste materials like wood flakes and wet bark to a boiler furnace. However, the soot build-up affected the boiler’s heat transfer efficiency and clogged the equipment.
They tried installing soot blowers, but these melted in the furnace’s high temperatures. The pressurized air also damaged the tubes, further adding to their equipment costs.
The manufacturer replaced soot blowers with AcoustiClean Sonic Horns and saw instant results. With the soot removed, the furnace temperatures remained steady and allowed optimum production time.
AcoustiClean is Versatile
AcoustiClean Sonic Horns can be mounted and hung on practically any kind of equipment.
Silos
Hoppers
Boilers
Cyclones
Baghouse Filters
Super Heaters
Air Heaters
Economizers
ID Fans
ESPs
Ducting
SCRs
Low Maintenance
The AcoustiClean system is designed to be efficient and very easy to maintain. The only parts that need to be replaced are the sound generators (every few years) and the titanium diaphragm (the only moving part, which is replaced yearly).
Contact us for more information about AcoustiClean Sonic horns, and how they can benefit your plant operations.
Posted by Control Concepts USA on | Comments Off on The Top 5 Bulk Material Flow Aids Ebook
If you already have a material flow aid, are you happy with it? Our ebook, The Top 5 Bulk Material Flow Aids: Pros, Cons, and Calculating ROI, is a must-read if you are struggling with your current flow aid and need to find a solution that works for you.
This ebook covers:
Pros and cons of different flow aids
Hidden costs of energy consumption, maintenance, and manpower hours
How companies have saved thousands of dollars after using AirSweep
And more
You can download the ebook here. If you have any questions about AirSweep and other material flow aids, please contact us.
Posted by Control Concepts USA on | Comments Off on Why is AirSweep Better than a Fluidizer?
Fluidizers are one of the most common material flow aids. They are cheap, easy to find, and often come pre-installed in vessels. But are they really effective? Turns out they are not. In this article, we cover why AirSweep is better than a fluidizer.
Fluidizers activate material with a combination of gentle aeration and vibration. The rubber discs are installed inside the hopper, bolted into place, and attached to air piping. The air causes the discs to flap and vibrate, causing air to radiate out. However, fluidizers aren’t the best flow aid to use for a variety of reasons.
Fluidizers don’t work for most powders and solids
Fluidizers work for very light powders like flour. However, they will not work on powders that are hygroscopic (or have a tendency to attract moisture) or powders with high fat or moisture content.
For example, R.M. Palmer—a candy manufacturer in Reading, Pennsylvania—had issues with cocoa powder packing and bridging in the hoppers. Cocoa powder has a 12% oil content.
Despite installing fluidizers, bin aerators, and vibrators, the company’s workers still had to scrape material off the vessel walls every three or four days. It was costing them time and money.
After trying so many different flow aids, the plant manager had grown skeptical. “A lot of manufacturers say their product will work but they don’t back it up,” Wieland said.
Fluidizers are expensive to use
While the initial cost of fluidizers may be low, the operating costs and losses from downtime are very high.
Since it has a small effective radius, you need to continuously operate several units to activate the material. This can lead to high energy consumption, which is very significant for countries where electricity is expensive.
Fluidizers are difficult to clean and maintain
The rubber discs, which are installed inside the vessels, can also trap material. They are difficult to clean, and can’t be exposed to some kinds of cleaning chemicals. This can create hygiene and sanitation issues—a big problem for industries like food and beverage, pharmaceuticals, cosmetics, and personal care.
How AirSweep is better than a fluidizer
That doesn’t mean that pneumatic flow aids can’t activate material. You just have to choose the right one.
AirSweep uses powerful air pulses that break up material blocks. It is effective for all materials—even moist powders, sticky compounds, or heavy bulk solids.
In fact, it was the only flow aid that solved R. M. Palmer’s material flow problem. After installing two AirSweep VA-06 units on the hoppers, the company has had “no breakdowns, replacements, or any problems whatsoever.” They were even able to add two production shifts per month, increasing output.
Wieland saw for himself how AirSweep was different from all other flow aids he had tried.
“AirSweep has a stronger air pulse than the bin aerators or fluidizers we previously installed. The air moves the powder down in a very large column so the powder doesn’t stick to the walls,” said Wieland.
Get the most powerful and cost-effective flow aid
AirSweep activates more material while using less energy. It is also easy to maintain and comes with the longest warranty in the business.
Contact us to find out more about how AirSweep can help improve your plant’s productivity while lowering your costs.
Posted by Control Concepts USA on | Comments Off on AirSweep Straight Shooter FAQs
AirSweep is one of the most powerful pneumatic flow aids in the industry. It can solve tough flow problems that even fluidizers, vibrators, and air cannons cannot.
The secret of AirSweep lies in its nozzle. It directs high-pressure, high volume, bursts of compressed air or inert gas along the inside walls of process equipment or vessels. The air pulses break the friction between the wall and the material to lift and sweep stalled material back into the flow stream.
The standard AirSweep releases air pulses at 360 degrees. This is typically used on hoppers, silos, mixers, and other process equipment with wide surface areas. However, there are applications that require air pulses to flow in a vertical column. For that, you can use the AirSweep Straight Shooter.
What is the AirSweep Straight Shooter?
The Straight Shooter model releases the pulse in a straight column. The technology and the performance quality are exactly the same. The nozzle has just been modified to concentrate the air pulses in one direction. Watch the demo:
How can the AirSweep Straight Shooter be used?
The “fire hose” effect of the air pulse makes these mini-blasters perfect for larger-sized pieces of material or for areas where the standard AirSweep cannot be mounted, such as inaccessible walls.
It can also be installed on chutes and ducts to push heavy material like cement or crushed ceramic tiles, or to flush vessels completely clean between batch runs. Some clients have used it to blow metallic brake dust off of mixer paddles (inside the mixer), and blow off flour and crumbs in a bakery application. Because they instantly reseal, these units can even be mounted inside the vessel to blast away areas of buildup.
Units can be easily mounted to blast in any direction using standard pipe elbows or fittings.
What is the AirSweep Straight Shooter’s activation range?
All AirSweep models and sizes are available as a Straight Shooter. The AirSweep team can select the right model for your application.
Like other AirSweep models, it is ATEX-certified as safe for hazardous environments. There are also USDA-accepted Straight Shooter models for sanitary applications.
Should I get a standard AirSweep or a Straight Shooter?
Paul the AirSweep guy demonstrates the difference between the standard AirSweep and the Straight Shooter, and how to adjust the position/location and angle of the Straight Shooter to achieve the desired material flow.
You can also contact us and tell us more about your process. We’ll customize a system and recommend the type of AirSweep that will give you the best results.
Posted by Control Concepts USA on | Comments Off on USDA-Accepted AirSweep: The “Cleaner” Flow Aid
Several industries need to use sanitary processes to comply with safety standards. This includes food and beverage, biotech and pharmaceutical, personal care, and cosmetics.
Cleanable and hygienically compatible with other plant systems
Made of materials compatible with cleaning solutions
Accessible for maintenance, cleaning, and inspection
Free of recesses, corrosion, or areas that could collect product or liquid
Able to facilitate validation and other sanitary protocols
Best flow aid for sanitary processes
The USDA- Accepted AirSweep is a powerful material flow aid especially designed for sanitary applications. It releases powerful air pulses that break material blocks, bridging, and ratholing. The unique sweeping action can even result in the vessel being flushed completely clean. Watch how it works:
Prevents spoilage and cross-contamination
Since AirSweep prevents stagnant material, plants avoid two of the biggest problems of sanitary manufacturing: spoilage and cross-contamination.
In fact, one of the world’s largest infant formula manufacturers uses the AirSweep USDA 135 and Straight Shooter models to break material blocks during production, and then clean the vessels between batch runs of regular and lactose-free formulas.
Works on all materials
The powerful air pulses can work on any material, including the sticky liquids or hygroscopic powders that are often used to make food, beverages, medicines, and cosmetics.
Many AirSweep customers used other flow aids like vibrators, fluidizers, and bin aerators, but still had to hammer the vessel to clear out material blocks. A US chocolate manufacturer said workers who scraped the vessel often bathed in big spills of cocoa powder. “They looked like giant cocoa puffs.”
AirSweep solved the problem. “It has a stronger air pulse than the bin aerators or fluidizers we previously installed. The air moves the powder down in a very large column so powder doesn’t stick to the walls,” said the coatings manager, Bob Wieland.
Airtight, minimal contact design
Only the nozzle tip has direct contact with the material. For each pulse, it opens for just 1/8” for ¼ seconds before snapping shut—for zero material feedback. The airtight design also guards against material retention and bacterial growth.
Easy to remove and clean
The AirSweep USDA-accepted models have flanged connections for quick installation or removal from mounting. It can be removed and disassembled with simple hand tools.
Can be used with corrosive cleaning materials
The stainless steel finish does not corrode or rust and can be safely cleaned with even the most potent disinfectants and chemicals.
Solve material blocks and meet safety standards. Contact us to find out more about AirSweep USDA-accepted models.
Posted by Control Concepts USA on | Comments Off on AirSweep Material Activation: More Powerful Than a Dozen Fluidizers – and Here’s Why
An aviation company that deices planes and runways uses pellets that are made of salt, binder, and other additives. Unfortunately, these materials are hygroscopic and have a tendency to clump and harden. The maintenance supervisor considered many different flow aids, but once he saw its description of “gentle vibration” he knew it wouldn’t work. “We needed something more…violent,” he said. He needed AirSweep.
When he saw an AirSweep video, he knew it was the solution they were looking for. The powerful air pulses could cut through moist and sticky materials like liquid cheese, heavy solids like gravel, and hygroscopic powders like cornstarch and titanium dioxide.
AirSweep Material Activation – More material moved per pulse
One AirSweep unit can activate more material than a dozen fluidizers. You can see this for yourself in this video that compares the two flow aids’ activation radius:
The smallest AirSweep, or model VA-06, activates a 1 to 2 foot radius, or about 300 to 600 millimeters. The AirSweep VA-12 activates a radius of about 3 to 4 feet, about 0.9 to 1.2 meters. The AirSweep VA-51 puts out a little more volume, so it activates a radius of up to 4 feet, or 1.2 meters, often even with denser products.
The role of pressure and volume
AirSweep harnesses air pressure and volume so each pulse can break material blocks and sweep them back into the flow stream. That’s why the system needs to have large pipes, headers, and receivers to run effectively.
Paul the AirSweep guy explains how this works, using the analogy of a garden hose and a fire hose.
AirSweeep is Powerful but energy efficient
Though AirSweep pulses require more plant CFM, it actually uses less energy and plant air than other flow aids.
AirSweep units are pulsed and run in a sequence, so even if you have 10 units on a vessel, they only pulse one at a time. It is more efficient than vibrators or fluidizers, which run continuously.
The AirSweep also uses less energy than air cannons and actually activates more material. One of the world’s largest cement companies had issues with clinker sticking to vessels and chutes. They tried using two AIRCHOC air cannons, but workers still had to use a bar to break the material.
AirSweep was an effective, fast, and simple solution. They were able to install it themselves in less than a day, and they never had to worry about clinker again. They even ordered 13 additional units for their various factories. “AirSweep works perfectly.”
Contact us to find out more about the AirSweep system, and how to set up one in your plant.
Posted by Control Concepts USA on | Comments Off on 3 Safety Hazards Caused by Bridging, Ratholing, and Poor Material Flow
Poor material flow doesn’t just affect productivity. It may lead to injury and hazardous plant environments, and compromise product safety.
Using an efficient flow aid, like AirSweep, can help protect the safety of your workers and your customers, and ensures that your company complies with industry regulations.
Fire hazards
A cheese company uses whey protein concentrate (WPC), which contains high moisture and fat and is prone to bridging over the discharge outlets. They had fluidizers and vibrators, but these still left a lot of caked material in the vessel.
Then one day, the caked material sparked a fire in one of their baghouses. Whey protein is classified as a combustible powder, and high concentrations can create a flammable environment.
While the fire was contained, bridging had become an urgent safety concern. They installed AirSweep, which cut through the sticky material and swept vessels completely clean. It now uses AirSweep in all its factories in the United States—to improve productivity and plant safety.
Many materials used in the food industry are classified as combustible: egg whites, powdered milk, cornstarch, sugar, flour, grain, potato, rice, etc. According to the Canadian Centre for Occupational Health and Safety, “The build-up of even a very small amount of dust can cause serious damage.”
The AirSweep USDA-accepted model can prevent material build-up and meets the sanitary requirements of the food industry.
Worker injury
Many plants resort to manual cleaning to clear stubborn material blocks. Workers have to hammer the vessel walls or climb into them to break up the blocks.
This process is tedious and exposes workers to several possible risks. Many powders and bulk solids can cause skin irritations or respiratory problems if they are directly handled or inhaled. Hammering and climbing into vessels can lead to falls and shoulder and back injuries.
Worker safety laws require companies to prevent worker injury and avoid giving tasks that the worker has not specifically been trained to do. The Occupational Safety and Health Administration (OSHA) standards include:
Prevent exposure to harmful levels of substances
Prevent exposure to loud noises that can damage hearing
Ensure the safety of workers climbing into enclosures such as bins
OSHA fines can reach up to $14,502 per violation. So, manual cleaning is neither an easy nor a cheap solution for material blocks.
Product spoilage and contamination
Ideally, materials in a vessel will have a first in/first out flow. This prevents spoilage and protects batch uniformity—and in some industries, like food and pharmaceuticals, this is critical for the consumer’s safety. Even cement can be unstable if the batch deviates from the correct proportions of materials.
Use AirSweep to solve poor material flow
AirSweep is used in those industries to achieve on-demand, first in/first out flow:
AirSweep can correct poor material flow to improve productivity and safety. Contact us to find out more about how AirSweep works, or ask for a customized proposal.
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