These collectors control contamination at their source. Photos or sketches for the systems described would bemore convincig. The slurry from the Wet Scrubbers is left to sit in a large pond or basin, allowing the captured particles to over time slowly settle to the bottom of the pond; afterwards the clean water is discharged. Gas-liquid contact: This is the entire basis for the operation of this type of system. In general, the process outlet is dry. Ability of fan to accommodate small changes in total pressure while maintaining the necessary air volume Divert some of the recycle slurry to a thickener, settling pond, or waste disposal area and supply clean water as makeup. Certain types of fittings such as elbows, mitered elbows and square ducts, can cause a nonuniform airflow which in turn will again lower performance Slip Ring Motors by contrast are general purpose or continuous rated motors that are used in applications where there is a need for an adjustable speed in the motor. An example of an Air to Cloth Ratio is provided below courtesy of http://www.usairfiltration.com, (Bag diameter in inches x pi x bag length in inches) Collectors can be arranged to unload their collected matter either in a continuous mode or at a predetermined time interval. Shut down fan, drain the system, and remove temporary strainers. Commonly, a special fan is used that will shred the paper scraps into smaller pieces/dust and then send it on to the dust collector. These are called positive pressure systems. While these are an effective filtration system one should note that they tend to be ineffective against fine particles as these tend to be redirected off of the water surface by the high surface tension. Straight Radial Bladed Fans provide the best choice for heavy particle loads. For processes generating hot, moist gases, preheat Baghouse to prevent moisture condensation, even if Baghouse is insulated. Ensure that scrubber is installed vertically. Type of material to be handled through the fan (For example, a Radial Blade Fan should be used with fibrous material or heavy dust loads, and a nonsparking construction must be used with explosive or flammable materials.) This design features a series of blades that extend straight out from the center hub. If you have some drawings or a fully description I can probably help you more. 1. Once installed, one end of the cartridge is sealed off and the open end is used for the clean exhaust. Total cloth area = 2,436 sq. For example Gas temperatures above 180 F (82C) will destroy many types of filter media (Filter Bags) used in Fabric Collectors (Baghouses). 1. The pulse jets still fire against the flow of air in the unit, but this is overcome by using compressed air, usually at 70 80 PSI. Notify me of follow-up comments by email. As with dry Cyclone Collectors, this type of system has the benefit of few to no moving parts and it is efficient for particles up to 5um and above. Clean and dry pneumatic lines associated with monitoring instrumentation. Observe stack (visually or with opacity meter). Power supply needs such as voltage, single or three phase AC and frequency

When certain types of materials are fluidized into the air they become highly combustible. Pleated Dust Collector Filter Conversion: Cost-Benefit Analysis, Industrial Dust Collectors Dust Collection Systems.

Recycling Then it is forced up through the various layers of the filtering media, and after being sent through a Mist Eliminator is sent back into the system via the exit port at the top. Afterward the Gas stream exits the collector through the outlet port and returns back into the system. Thank you very match for your help. We include a brief overview of the pros and cons of each to help guide you in identifying the right option for your work environment.

Depending on the particular desired application is there are a number of different designs available to choose from with a capacity of 200 to 2,000 ft3/min. Centrifugal Collectors create a vortex in the airstream within an enclosure, similar to water going down a drain. These fans are highly sensitive to particulate buildup and are used for high airflow, low pressure applications.

Inlet and outlet valves are placed at the inlet and outlet of each dust collector. Check the direction of fan rotation; if rotation is wrong, reverse two of the tree leads on motor. Pressurized piping system for wet material (Slurry). Some of the feed is introduced to the granulator via Front-end loader straight after a curing belt, obviously the moisture content is match higher at this stage (not a stage per say, rather a different feed). Spot-check bag tension. With recycle flow on, set valves to determine operating conditions for desired flow rates. This type of system is widely used to collect fumes and particles generated by welding, grinding or burning operations. The differences in design, operation, efficiency, space requirement, construction, and maintenance needs, as well as the initial start up, operating, and maintenance costs differ greatly between various products and systems. 1. The water hitting the extremely high speed air causes it to instantly atomize. However, we do recommend you place a water trip and drain directly on the air header tank to enable any bit of moisture left to be drained out before being used in the baghouse. Leave inlet control damper closed for 2 min to allow fan to reach speed. Spot check for bag leaks. In a Reverse Air Baghouse, filter bags are connected to a cell plate on the bottom of the Baghouse and are suspended from an adjustable hanger frame on top. Backward Curved Bladed Fans contain blades that are positioned away from the fans rotation direction. Check ductwork for leakage and excessive flexing, Line or replace as necessary. Between the two, the Multiple Cyclone Collector will operate more efficiently because of being longer in length and smaller in dynamiter.

baghouse Electrostatic Precipitators use electrostatic forces to collect dust from the Gas stream. There are many reasons why having a proper Dust Collection System installed in your facility is needed, a few important reasons are: To protect employees and society from exposure to pollution, The same basic mechanics are present in all of them, the main difference being how filter bags are cleaned. The large amount of different Wet Scrubbers in use makes it impossible to comment on every single design in this article. Cyclone Collectors. Check insulation dampers and place scrubber in series with primary operation. This design is more efficient than simple propeller types and is often used in moving Gas streams filled with condensable fumes or pigments. Types of Dust Certain types of Collectors have a great deal of physical contact between the particles and the Collector itself. 5. Check packing glands. Required operational temperature (For example, sleeve bearings are suitable to 250 F; ball bearings to 550 F.)

Line high-efficiency cyclone with refractor or erosion-resistant material. However these fans are in most applications used only for clean air. Check screw conveyor for wear or abrasion. Verify proper operation of dampers and inspect for leakage. To the point, what are the possibilities for dry treatment for the so-called moist (sticky) dust, considering dry applications? Fabric Collectors (commonly known as a Baghouse) are among the most widely used dust collection systems. The cleaning cycle of the Pulse Jet collectors provides a more complete cleaning and reconditioning of the filter bags than in the Shaker, and Reverse Air designs. In these environments, a baghousewill handle and most efficiently filter your dust laden air. Check stack (if cyclone is only collector). Wet Scrubbers are further categorized by pressure drop (in inches water gauge) as follows: Low-energy scrubbers (0.5 to 2.5) Required fields are marked *. Total Cloth area = 144 x total number of bags

Send bag in for permeability test and review with manufacturer, Rebuild compressor or consult manufacturer, Check pilot valves, springs, and diaphragms, Run the system with hot air only before process gas flow is introduced, Keep fan running for 5 to 10 min after process is shut down, Lower dewpoint by keeping moisture out of system, Eliminate direct metal line through insulation, Repressurizing air causing condensation (PJ), Use process gas as source of repressurizing air, 1. All electrostatic Precipitators have four main components: A Power supply to provide the system with electricity The dirty water collects at the bottom of the tank and the clean air (mist) exits from the top of the collector. The now ionized particles travel pass the next set of electrodes (the collection section) that carry a positive charge.

Build up of debris in the inlets, blades, passages as well as obstructions should be checked and remedied

Inertial separators work by making use of one or more of the following forces centrifugal, gravitational, and inertial in order to separate dust from the airstream. They benefit from low initial cost, direct return of captured material to the main material flow, and very low space requirements. Further, for a high dust load system a great amount of dust storage is needed. I have being doing research and I havent seen any pulse jet baghouse with the fan upstream of the dust collector. Both Types can also be constructed in explosion and dust ignition proof models to protect against accidental ignition of dust particles. document.getElementById( "ak_js_1" ).setAttribute( "value", ( new Date() ).getTime() ); Get notifications when we post new content. 3. Before we dig into the differences between some of the baghouse styles, you need to consider your dust propertiesandair-to-cloth ratio. This collector has a relatively low efficiency compared to other kinds of Wet Scrubbers. Check gaskets, valves, and other openings for leakage. The packing media allows for a very wide distribution of the water, which in turn allows the Gas stream to have the maximum contact with the water during its passage though the collector. Centrifugal Collectors. Once a system has been installed in the field, inevitably certain differences between design and field installation will require a field test to be done to find the exact measurements of static pressure and volume. A few brief points are good to keep in mind during the installation process that can cause your real world values to change from the original design specifications: Elbows and bends near the fans discharge will increase the systems resistance thereby lowering your fans performance Corrosive and other chemicals can erode certain metals and other materials used in the construction of many Collectors. The specifics of the process are irrelevant, since the process does not allow for change in moisture content. Electrostatic Forces: An increased attraction can occur between the dust particles and the filter media when an electrostatic charge is found on the dust particles.

A standard 6 bag has a 5-7/8 diameter Check hoses and clamps. Totally Enclosed Motors have an exterior fan mounted unto the backside of the motor drive end. Electric Motors are usually grouped as either Induction, or Synchronous designs. The dust filled air then needs to be treated and the contaminates removed, before the air can be recirculated back into the facility or dispersed into the atmosphere. 2.

Copyright 2021 Baghouse.com | Website designed by. It is used to move large an amount of air against very low static pressure from the rest of the system. Also like a Settling Chamber its relatively simple design and low maintenance needs make it an excellent choice for the beginning of any large scale collection system. * S = Shaker Pressurized piping systems are needed when transporting the slurry made from using a Wet Scrubber design. The air is blown across the axis of the fan hence the name Axial Flow Fans. Inspect screw-conveyor bearings for lubrication. Yes, they can operate this way. This design is not suitable for application where particles that can damage the interior of a motor are found in the ambient atmosphere around the motor. Supposedly, to clean one of the collectors, its respective valves are completely closed to shut off the flow of air through the collector being cleaned. This timer signals a solenoid valve to start the cleaning cycle when it detects a certain amount of build up on the bag. Reverse Jet (Or Pulse Jet). The exact dangers and hazards of the contaminates to be captured, its potential as a public health risk or nuisance, site location, the allowable emission rate by the regulatory body for the given substance, characteristics of the dust, and any recyclable value.

One type of application where positive pressure systems might be used is paper recycling. shaker, reverse, and pulse-jet)that are commonly used in most industrial processing and manufacturing applications. 4. They usually employ either a Mechanical Shaker, or a Pulse Jet system for cleaning.

However its main advantage is it can handle very heavy dust loads without getting backed up. Record the valve positions as a future baseline. If this is the case, rotary air locks, or tipping valves need to be used in order to maintain a positive air seal and thus avoid massive pressure loss that would be detrimental to the normal operation of the system. I would recommend you look around on LinkedIn for a group that focused on ESP technology, and ask there. In a belt driven system one must check the motor sheave and fan sheave are properly aligned and that proper belt tension is present. PJ = Pulse Jet. The two main types are: Fabric Collectors Use fan current to indicate gas flow.

Inspect fans for corrosion and material buildup. The Tube Axial design is very similar to a normal propeller type fan, except that the propeller is enclosed in an open ended cylinder. The majority of Single State Precipitators in use today are of the plate variety. The diverging shape of the scroll also converts a portion of the velocity pressure into static pressure. A Multiple Cyclone Collector works in the same manner as the Single Cyclone variety albeit with several small dynamiter cyclones instead of just one. I need to know why it goes from moist to dry conditions. The surface of the filter bag is dusted so that the dust collector does not work properly. However, implementing the baghouse solution might yield extensive operational malfunctions.

These systems use a scrubbing liquid (usually water) to filter out finer dust particles. The particles are trapped in the liquid and are then by means of centrifugal force thrown off the spinning fan blades unto the sides of the collector where they eventually settle at the bottom enabling them to be collected. While they can be fitted with wear protection, this type of blade can still become backed up if the particle load gets to be too heavy. Assure that dust is being removed from system. Baghouses are ideally suited forlargevolumeapplications with airflow exceeding 1,000 CFM or when high temperature applications are above 375 degrees. All Disposal Systems have to accomplish these four objectives without further contaminating the environment, in order to be effective in their role in the Dust Collection System: Collected material from the hopper must be removed In the process, the larger particles fall to the bottom of the chamber and can be collected from there. This type of collector is best used in the collection of coarse of larger particles. Wet Scrubbers are ideal: For the collection of explosive material The two most common types used in Dust Collection Systems are: Squirrel Cage Motors are generally used where a constant speed is desired Have low capital costs and small space requirements, Have high operating and maintenance costs, Require corrosion-resistant materials if used with acidic gases, Are able to collect gases as well as particulates (especially sticky particulates), Require a precleaner for heavy dust loadings, Cause water pollution; require further water treatment, Are susceptible to erosion at high velocities. Cleaning is accomplished by vibrating the electrodes either continuously, or at a timed interval, causing the captured dust to fall off into a hopper below. Check gas saturation, liquid flows, liquid levels, fan pressure drop, duct pressure drops, and scrubber pressure drop. Install temporary strainers in pump suction line and begin liquid recycle. This Baghouse has a relatively low Air to Cloth Ratio requiring large amounts of space. Over time a layer of cake dust is built up on the surface of the filter bags. 2. A Direct Drive fan is run directly off of a drive shaft from the motor, this provides for lower space needs, but places the fan at a constant unchangeable speed. Check gaskets on doors. Have collection efficiencies in excess of 99% for all particulates, including sub-micron-sized particles, Do not respond well to process changes such as changes in gas temperature, gas pressure, gas flow rate, gaseous or chemical composition, dust loading, particulate size distribution, or electrical conductivity of the dust, Have lower pressure drop and therefore lower operating costs, Have a risk of explosion when gas stream contains combustibles, Can operate at high temperatures (up to 1200 F) and in colder climates, Can remove acids and tars (sticky dust) as well as corrosive materials, Require large space for high efficiency, and even larger space for dust with low or high resistivity characteristics, Allow increase in collection efficiency by increasing precipitator size, Require special precautions to protect personnel from exposure to high-voltage, Require highly skilled maintenance personnel, Forward curved impeller installed backwards, Change fan rotation by reversing two of the three leads on the motor, Impeller not centered with inlet collar(s), Make impeller and inlet collar(s) concentric, Increase fan speed by installing smaller diameter pulley, Elbows or other obstructions restricting airflow, Install straight length of ductwork, at least 4 to 6 duct diameters long, where possible, Increase fan speed to overcome this pressure loss, Remove obstruction or redesign ductwork near fan outlet, Projections, dampers, or other obstructions near fan outlet, Actual system more restrictive (more resistant to flow) than expected, Decrease systems resistance by redesigning ductwork, Open or adjust all dampers according to the design, Backward inclined impeller installed backwards (high horsepower), Install impeller as recommended by manufacturer, Redesign ductwork or add restrictions to increase resistance, System has less resistance to flow than expected, Reduce fan speed to obtain desired flow rate, Gas Density lower than anticipated (due to high temperature gases or high altitudes), Calculate gas flow rate at desired operating conditions by applying appropriate correction factors for high temperature or altitude conditions, Fan inlet and/or outlet conditions not same as tested, Backward inclined impeller installed backwards, Calculated horsepower requirements based on light gas (e.g., high temperature or high altitude) but actual gas is heavy (eg.,cold startup), Install outlet damper, which will open gradually until fan comes to its operating speed, Fan not operating at efficient point of rating, Motor too small and overload protector has broken circuit. Las Vegas, NV 89108 Record all system pressure drops under clean conditions. Check bearings, drive mechanisms, temperature rise, sprocket alignment, sprocket wear, chain tension, oil level, and clarifier rakes. = 5.34 : 1. | Dominick DalSanto is an Author & Environmental Technologies Expert, specializing in Dust Collection Systems. Great care must be taken by the operators of this system to ensure that no leakage occurs which would result in an environmental hazard caused by water pollution.



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