Non-Destructive Dust Removal

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Verity Dixon
5 years ago
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1 Non-Destructive Dust Removal

ACOUSTIC CLEANING SYSTEMS...BLACK MAGIC, OR DO THEY REALLY WORK? Horn Body Driver Diaphragm The principle behind acoustic cleaning is very simple: sound is a vibration through air that can be heard.

If a vibration is imparted to a dust-coated surface with enough intensity, dust will be dislodged from that surface, whether the vibration is caused by sound waves or a mechanical impact.

2 ACOUSTIC CLEANING SYSTEMS...BLACK MAGIC, OR DO THEY REALLY WORK? Horn Body Driver Diaphragm The principle behind acoustic cleaning is very simple: sound is a vibration through air that can be heard. Vibrations are effective at dislodging dust from surfaces, and the source of the vibration doesn t matter. If a vibration is imparted to a dust-coated surface with enough intensity, dust will be dislodged from that surface, whether the vibration is caused by sound waves or a mechanical impact. Nothing magical about acoustic energy...it s just a source of vibratory energy. Air pressure The frequency and intensity of the vibration are critical factors in acoustic cleaning. To be effective, the frequency should be low, but not too low, and the intensity of the sound (decibel level) must be great enough to remove the collected particulate. Compressed air is introduced to the driver assembly of an acoustic horn. The pressure builds up rapidly, causing the diaphragm plate to flex. BHA s Powerwave acoustic horns are scientifically designed to produce powerful pulses of sound energy that will resonate and dislodge dust from fabric filters, boiler tubes and heat exchangers, precipitator collecting plates and high voltage discharge electrodes, hoppers and dust lines, even SCR catalyst. Acoustic energy has been used successfully for more than 20 years to improve the efficiency of air pollution control equipment in many applications, and has even enabled some plant operators to use acoustic horns as their sole cleaning devices! THE ROLE OF FREQUENCY AND INTENSITY Air escapes past the flexed titanium diaphragm plate into the horn, reducing the air pressure in the driver. The pressure reduction allows the diaphragm to snap back quickly, creating a strong pulse in the horn body. Typically, the lower the frequency, the more effective a horn will be at dislodging dust or particulate. However, extremely low-frequency sound waves (produced by infrasonic devices) can be dangerously close to the resonate frequency of the structure or vessel and can cause damage to the structure or loosen or crack welded or bolted connections. Powerwave acoustic horns operate at 75 hertz or above, well above the frequency of the structure, and cannot damage structural components. Low frequency, high decibel sound is proven to be the most effective at removing particulate, without damaging the equipment. The pulses travel through the horn, where they are amplified by the bell shape, and become powerful bursts of acoustic energy capable of blasting dust away from surfaces. The length of the horn s bell is one factor that determines the main, or fundamental, frequency of the horn. The longer the bell, the lower the frequency. The horn pictured has a long, curved bell, and is often used to dislodge slag from boiler tubes. Acoustic cleaning is accomplished through particle displacement, changes in pressure that break the bond of the particles from themselves and the structure. Lower frequencies produce greater displacement (or changes in air pressure) and will clean a larger cross sectional area. BHA s family of acoustic products are engineered and tested to produce the cleaning power you need, with moderate cost, low maintenance, and high efficiency. We publish the frequency and intensity ratings of our horns, so you know what you re getting. (See inside)

PROVEN APPLICATIONS FOR BHA POWERWAVE ACOUSTIC CLEANING SYSTEMS BOILER TUBES/HEAT EXCHANGERS Powerwave horns can be used to supplement or replace steam sootblowers in industrial or utility boilers.

The horns can be operated more frequently than sootblowers, and keep the tubes cleaner without parasitic steam use.

Powerwave acoustic horns are also extremely effective for removing particulate from rotary or tubular heat exchanger surfaces.

flexing of the fibers. Acoustic energy is gentle to the fabric, but effectively resonates and dislodges dust accumulations from the filters.

(Pulse-jet baghouses usually require some traditional pulsing, unless BHA-TEX membrane filters are used.

3 PROVEN APPLICATIONS FOR BHA POWERWAVE ACOUSTIC CLEANING SYSTEMS BOILER TUBES/HEAT EXCHANGERS Powerwave horns can be used to supplement or replace steam sootblowers in industrial or utility boilers. Many boiler operators have found that they can reduce or eliminate opacity spikes associated with sootblower use by using Powerwave horns to keep the tubes clean. The horns can be operated more frequently than sootblowers, and keep the tubes cleaner without parasitic steam use. Annual maintenance expenses are much lower than for retractable sootblowers, as Powerwave horns have just one moving part, a tough titanium diaphragm plate. Powerwave acoustic horns are also extremely effective for removing particulate from rotary or tubular heat exchanger surfaces. BAGHOUSE FABRIC FILTERS/ELEMENTS Traditional fabric filter cleaning methods (shaking, air flow reversal, or pulsing) create motion in the filters that can shorten filter life by causing abrasion and flexing of the fibers. Acoustic energy is gentle to the fabric, but effectively resonates and dislodges dust accumulations from the filters. Acoustic energy can allow reduced frequency of traditional cleaning cycles, and in some cases can eliminate the need to use any other method of cleaning. (Pulse-jet baghouses usually require some traditional pulsing, unless BHA-TEX membrane filters are used.) PRECIPITATOR COMPONENTS Precipitator internals are cleaned using either externally-mounted rappers, or internally-mounted rotating hammers. Both types of conventional cleaning systems literally hammer the dust free from the surfaces, allowing it to fall into the hoppers. Cleaning cycles often result in some re-entrainment of the dust, and the effect of the mechanical impacts used tend to cause cracks, distortion, and fatigue of the collecting surfaces, along with failures of the discharge electrodes. Powerwave horns clean these surfaces without imparting mechanical stress and fatigue, and sometimes prove to be so effective that the conventional rapping systems are no longer necessary. SELECTIVE CATALYTIC REDUCTION (SCR) EQUIPMENT Historically, SCR cleaning was done using steam sootblowers, although the parasitic steam usage could cost many thousands of dollars per year, and sootblower maintenance costs were often high. Because sootblowers are operated infrequently, the amount of ash dislodged is excessive, and can result in re-entrainment and "puffing" at the stack, as well as reduced catalytic reaction between sootblowing cycles. Moreover, the action of steam sootblowers tends to erode and shorten the life of SCR catalyst. Acoustic energy is a viable, effective, and comparatively inexpensive method for cleaning SCR catalyst. Advantages: lower cost and operating expense, low maintenance cost, and very small size compared with steam sootblowers. MATERIAL HANDLING (HOPPERS, FANS, SILOS, DUCTWORK) Powerwave horns are designed in many different configurations that allow them to be used in hoppers, I. D. fans, bins, and ductwork. The more compact models can be used to fluidize dust in pneumatic conveyor lines and hopper emptying valves, while specialized models are used to keep fan blades clean, balanced, and vibration-free. Acoustic horns can eliminate the need for sledgehammering, rodding out hopper poke holes, or dangerous work unclogging ash vessels.

ACOUSTIC HORN SPECIFICATIONS ESP-75 Fundamental Frequency (Hertz)...75 Hz Output Power Level (Decibels)...147 db Material....Cast Malleable Iron Weight...174 lbs. (78.43 kg) Length...92.

..62 lbs. (28.12 kg) Length......27.30 (69.3 cm) D-75 Fundamental Frequency (Hertz)...75 Hz Output Power Level (Decibels)...147 db Material.

..147 db Material...Cast iron/carbon steel (Stainless steel fabricated cone) Weight...130 lbs. (58.97 kg) Length...58.8 (149.35 cm) Height...52.7 (133.86 cm) Air Consumption.

3 cm) D-Fluidizer Fundamental Frequency (Hertz):...220 Hz Output Power Level:...150 db Material:...Cast Stainless Steel Weight:...32 lbs. (14.5 kg) Length...15.2 (38.

4 ACOUSTIC HORN SPECIFICATIONS ESP-75 Fundamental Frequency (Hertz)...75 Hz Output Power Level (Decibels) db Material....Cast Malleable Iron Weight lbs. (78.43 kg) Length ( cm) D-230 Fundamental Frequency (Hertz) Hz Output Power Level (Decibels) db Material...Cast Iron Weight (one piece bell)...64 lbs. (29.03 kg) Weight (two piece bell)...62 lbs. (28.12 kg) Length (69.3 cm) D-75 Fundamental Frequency (Hertz)...75 Hz Output Power Level (Decibels) db Material...Cast Malleable Iron (Stainless steel fabricated cone) Weight lbs. (51.71 kg) Length ( cm) DC-75 Fundamental Frequency (Hertz)...75 Hz Output Power Level (Decibels) db Material...Cast iron/carbon steel (Stainless steel fabricated cone) Weight lbs. (58.97 kg) Length ( cm) Height ( cm) Air Consumption PSI D-360 Fundamental Frequency (Hertz) Hz Output Power Level (Decibels) db Material...Cast Stainless Steel Weight...37 lbs. (16.78 kg) Length (41.3 cm) D-Fluidizer Fundamental Frequency (Hertz): Hz Output Power Level: db Material:...Cast Stainless Steel Weight:...32 lbs. (14.5 kg) Length (38.61 cm) Flange and Tube Installation Options BHA supplies all the flanges and penetrations needed to install horns through the sides of hoppers, bins, or any vessel requiring cleaning. Custom throat flange kits from BHA make positioning horns easy in nearly any location.

ACOUSTIC HORN SPECIFICATIONS Installation Options AH-25A Fundamental Frequency (Hertz):...125 Hz Avg. Power Weighted Mean Frequency:...164 Hz Avg. Power Level <300 Hz (decibels):...145 db Material:.

2 bar) Powerwave Horns are easier to install than you might think. Most horns are designed to fit inside existing openings, like access doors, inspection ports, or poke holes.

5 ACOUSTIC HORN SPECIFICATIONS Installation Options AH-25A Fundamental Frequency (Hertz): Hz Avg. Power Weighted Mean Frequency: Hz Avg. Power Level <300 Hz (decibels): db Material:...Carbon Steel **(Stainless steel available) Maximum Operating Temperature: F (343 C) Weight: lbs. (50kg) Air Consumption: PSI ( bar) Powerwave Horns are easier to install than you might think. Most horns are designed to fit inside existing openings, like access doors, inspection ports, or poke holes. Standard plant air can be used to drive the horns; instrument quality air is not required. Horn Driver AH-15 Fundamental Frequency (Hertz): Hz Avg. Power Level <300 Hz (decibels): db Material:...Carbon Steel **(Stainless steel available) Maximum Operating Temperature: F (343 C) Weight:...70 lbs. (32 kg) Air Consumption: PSI ( bar) Stainless Steel Flex Hose Air supply requirements are fairly simple, and are customized for each installation. Controls can be as sophisticated as rapper controls, or as simple as solenoids and timers. Regulator Solenoid Valve Locking Ball Valve Air Filter Horns can be chain-hung inside baghouses or vessels, although most operators prefer to have easier on-line access to the drivers. AH-10 Fundamental Frequency (Hertz): Hz Avg. Power Level <300 Hz (decibels): db Material:...Carbon Steel **(Stainless steel available; Food Grade available on request) Maximum Operating Temperature: F (343 C) Weight:...40 lbs. (18 kg) Air Consumption: PSI ( bar) The D-Series horns utilize tube mountings to facilitate ease of installation on vessel walls and other enclosures. tube horn wall Note: For higher temperatures or corrosion resistance, horns can be manufactured from various alloys. Mouth-flange mountings are used for roofs of baghouses or silos. Mouth-flange mountings are also used on precipitator roof installations. The D-fluidizer horn is installed on a tube to facilitate hopper mounting at the correct angle in order to direct the sound energy to the problem area.

POWERWAVE ACOUSTIC CLEANING SYSTEMS ARE USED IN MANY APPLICATIONS.

well, the plant stopped using the conventional tumbling hammers.

Supplements or replaces rappers or tumbling hammers.

Reduces mechanical fatigue of collecting and discharge electrodes.

Powerwave acoustic horns provide excellent cleaning of rotary or tubular heat exchangers.

BAGHOUSES Supplement (or eliminate) sootblowers with acoustic energy!

Powerwave acoustic horns can be chain-hung inside baghouses to provide effective cleaning of filters,

Reduces differential pressure. Reduces filter wear (especially in shaker or reverse air baghouses).

6 POWERWAVE ACOUSTIC CLEANING SYSTEMS ARE USED IN MANY APPLICATIONS... ELECTROSTATIC PRECIPITATORS Powerwave horns cleaned the internal components of this precipitator so well, the plant stopped using the conventional tumbling hammers. Viewing the roof of a precipitator that is cleaned using only Powerwave acoustic horns. Supplements or replaces rappers or tumbling hammers. Eliminates hopper bridging, ratholing, and sidewall buildup. Reduces re-entrainment. Reduces mechanical fatigue of collecting and discharge electrodes. Increases electrical field strength and collection efficiency. Powerwave acoustic horns provide excellent cleaning of rotary or tubular heat exchangers. Powerwave acoustic horns offer reduced SCR maintenance costs, as compared to cleaning with sootblowers. BAGHOUSES Supplement (or eliminate) sootblowers with acoustic energy! Horns are supplied in a variety of materials for operation in high temperatures. Powerwave acoustic horns can be chain-hung inside baghouses to provide effective cleaning of filters, without the abrasion and flexing. Enhances dust removal from filter elements or bags. Reduces differential pressure. Reduces filter wear (especially in shaker or reverse air baghouses). Helps eliminate blinding. Increases filter life expectancy. Flange Mounting Powerwave acoustic horns eliminate common material buildup problems in bins, hoppers, silos, and pneumatic conveying lines. Easily installed through poke holes or access doors, Powerwave horns provide intense acoustic energy to break up and remove blockages and stubborn deposits, without the mechanical fatigue caused by vibrators, shakers, or sledgehammers.

ACCESSORIES Powerwave horns can be positioned in existing sootblower openings.

Keeps heat transfer surfaces clean for maximum heat rate efficiency.

Increases air heater efficiency. Extends boiler duty cycles.

the process gas temperature inside the bell from dropping below the dew point.

Wrap could provide benefits to the operation of the acoustic cleaning system.

Increases catalyst exposure to flue gases. Reduces catalyst erosion.

where external noise levels are a concern.

issue, the Powerwave Insulator can eliminate danger to personnel and protect the acoustic cleaner from condensation and

Stops bridging, arching, or ratholing in hoppers, bins. Eliminates fatigue and cracks caused by vibrators.

7 ACCESSORIES Powerwave horns can be positioned in existing sootblower openings. BOILER TUBES AND AIR HEATERS Compact, curved Powerwave horns can easily be retrofit in existing boiler access doors. Keeps heat transfer surfaces clean for maximum heat rate efficiency. Reduces or eliminates sootblower use, steam consumption. Dramatically reduces maintenance requirements. Increases air heater efficiency. Extends boiler duty cycles. The Powerwave Thermal Wrap is designed to easily install around the exposed bell sections of the acoustic cleaner, keeping the process gas temperature inside the bell from dropping below the dew point. The high temperature conditions found in SCRs, baghouses, boilers, and precipitators are areas where the Powerwave Thermal Wrap could provide benefits to the operation of the acoustic cleaning system. Powerwave horns can be positioned across catalyst beds to remove flyash without the need for sootblowers. Increases catalyst exposure to flue gases. Reduces or eliminates sootblower use, steam consumption. Dramatically reduces maintenance requirements. Reduces catalyst erosion. SCR EQUIPMENT The Powerwave Insulator is an effective way to minimize external noise created by acoustic cleaners in areas where external noise levels are a concern. Also, on high temperature applications where the temperature of the external parts on the acoustic cleaner are a safety issue, the Powerwave Insulator can eliminate danger to personnel and protect the acoustic cleaner from condensation and corrosion. Powerwave AH-25 horns keep this baghouse operating at low differential pressure and high collection efficiency. Stops bridging, arching, or ratholing in hoppers, bins. Eliminates fatigue and cracks caused by vibrators. Eliminates sledgehammering of stubborn clogs. Eliminates hazardous rodding or cleaning jobs. HOPPERS, MATERIAL HANDLING The PVS (Powerwave Verification System) is designed to detect a failure of acoustic cleaners in a multihorn system. This detection can provide an immediate warning to plant personnel of a potential malfunction. The PVS system is capable of being used in high temperature and dusty environments, such as SCRs, baghouses, boilers, and precipitators.

BHA KNOWS ACOUSTIC CLEANING SYSTEMS...WITH OVER 20 YEARS EXPERIENCE IN THE FIELD Acoustic Cleaning Systems Help To: Increase production by maximizing equipment performance.

Reduce excessive material buildup which leads to unscheduled maintenance expenses and downtime. Reduce material flow problems.

Horns are constructed with superior quality steel bells and drivers. Stainless steel is also available for high temperature, corrosive, and food grade applications.

Low cost, compared with other cleaning systems. Variety of horn control options available, including existing timers or rapper control systems.

8 BHA KNOWS ACOUSTIC CLEANING SYSTEMS...WITH OVER 20 YEARS EXPERIENCE IN THE FIELD Acoustic Cleaning Systems Help To: Increase production by maximizing equipment performance. Decrease energy costs resulting from high differential pressure in baghouses. Improve performance of precipitators with poor electrical field strength. Reduce excessive material buildup which leads to unscheduled maintenance expenses and downtime. Reduce material flow problems. POWERWAVE ACOUSTIC HORN ADVANTAGES Low fundamental frequencies and high decibel output produces more energy for superior cleaning. Increased power means each horn cleans more surface area. Horns are constructed with superior quality steel bells and drivers. Stainless steel is also available for high temperature, corrosive, and food grade applications. Ease of installation through existing openings and access doors. Simple, inexpensive maintenance (only one moving part). No exotic air supply or special plumbing required. Low cost, compared with other cleaning systems. Variety of horn control options available, including existing timers or rapper control systems. WIDE RANGE OF PROVEN APPLICATIONS Boiler tubes and air heater thermal transfer surfaces Electrostatic precipitators Fabric filter dust collectors (baghouses) Hoppers, bins, silos, pneumatic conveyors, ductwork Selective Catalytic Reduction (SCR) equipment Material handling equipment ENGINEERING MAINTENANCE REBUILDS TECHNOLOGY For additional information, call your BHA account representative at our toll free number, GERMANY SPAIN SWITZERLAND MEXICO PHILIPPINES CHINA UNITED KINGDOM INDIA BRAZIL CANADA ITALY Other BHA Manufacturing Facilities: Slater, Missouri USA Newport News, Virginia USA, and Folkston, Georgia USA. BHA has service and technical engineers in the United States, Mexico, Canada, Australia, and Japan 8800 East 63rd Street Kansas City, Missouri USA Fax P6MK200 Rev. C Lit. No /11/03

BHA Powerwave Acoustic Cleaning Systems Powerful cleaning to help increase performance

BHA Powerwave Acoustic Cleaning Systems Powerful cleaning to help increase performance BHA Powerwave acoustic cleaning systems can significantly improve the cleaning process for air pollution control equipment