BAG HOUSE AND ACCESSORIES

BAG HOUSE AND ACCESSORIES

PRODUCT INTRODUCTION

Bag-house filter systems are used to extract airborne metallic dust particles from steel melting furnace, thereby releasing clean air into the atmosphere. Dust laden air enters through the bag-house filters entry inlet. This incoming air strikes the filter bags, causing the heavier material to fall to a hopper bottom. The air with the lighter and smaller materials is filtered by the filter bags and clean air with standard emission rates of 10-100mg/Nm3 is exhausted to atmosphere through specially designed stack.

DUST COLLECTION PROCESS.

The Particulate laden gas is pulled through the baghouse inlet by centrifugal blowers. The blower is located on the downstream side of the baghouse, this pulling gas through the filter media, it is termed a negative pressure bag house.

On the Top of filter bags orifice, air is pulsed through high pressure jets into the interior of the filter bags. This action causes the bags to ripple, knocking off the “cake”/ dust from the outside of the filters. This material/dust is discharged to the residual collecting conveyor system through a rotary air lock fixed at the bottom the hopper system.

Inside the bag filter, cylindrical bags made of polyester / special material (as per required in the application) are intercepted in the flow path of air and the particles are collected onto these filters by mechanisms interception, inertial impaction and diffusion. The pulse jet collector is continuous automatic filter capable of filtering dust laden air through a felted non-woven filter media.

The hoppers are located below the filter bags. Collection hoppers are used to temporarily store the collected ash that is dislodged from the filter bags by the cleaning mechanism process. Many hopper’s are designed to include vibrating mechanisms to assist in dislodging the cake/ dust inside the hopper when discharging the particulate matters. The collected dust material in hopper is discharged from the bag-house filters through a rotary air lock to be collected in the residual collecting conveyor system.

BAG HOUSE :- TOP CHAMBER , DIRTY AIR CHAMBER & HOPPER

TOP CHAMBER

Top Chamber are also known as Clean air chamber. This chamber only contains the clean filtered air which is passed through the filter bags. The top chamber is fabricated with mild steel 5mm thick plate and sealed on all sides to prevent clean air leakage. This chamber contains a tube sheet to with-hold the filter bags which hangs down around 4mtrs below the top chamber.

DIRTY AIR CHAMBER

The dirty air chamber as the name suggests contains dirty air. This chamber is bolted and sealed below the top chamber which houses the filter bags. The DAC helps in accumulting the dirty air dust particles which are settles below the DAC in hopper. The DAC is fabricated with mild steel 5mm thick plate and sealed on all sides. The top face is bolted to top chamber and bottom face is bolted with the bag house hopper with sealing cloth to prevent any air lekage.

HOPPER

Hoppers are dust collection equipments usually installed below the DAC. Once the dust releases from around the filter bags it gets settled in the hopper which is then discharged from the hopper opening at the end using rotary valve.

Hoppers are constructed with a mild steel plate 5 mm thick having sealed edges and and angle welded to the top for bolting with DAC. The joints are properely sealed with asbestos cloth so to avoid the dust being escape in the sorrounding air.  

PULSING VALVES &  PULSING HEADERS

SOLENOID OPEREATED PULSING VALVES

Solenoid Opereated pulsing Valves (SOVP’s) are valves that use an electrical charge to open and close the valve, which allows for precise control of the airflow. This makes them ideal for air cleaning systems, as they can be set to pulse the air at specific intervals and provide the necessary amount of airflow for efficient air cleaning.

The advantage of SOPVs over other types of pulsing valves is that they are more reliable and have a longer lifespan. Since they are operated by a solenoid, they are less susceptible to damage and wear due to frequent use. Additionally, they are much less likely to become stuck open or closed, which can cause problems in air cleaning systems.

When selecting an SOPV for an air cleaning system, it is important to consider the airflow requirements of the system and the type of solenoid being used. The solenoid must be strong enough to open and close the valve, while also providing enough pressure to ensure the required airflow. Additionally, the valve must be designed to handle the type of pressure and flow of the air cleaning system.

PULSING HEADERS

Pulsing headers as the name suggest are headers having size _______ and _____ connections for pulsing vales. The inlet is connected to _____(capacity) compressor and outlet is connected to pulsing valves having the air flow of ___.  FEC designed and manufactured pulsing headers are robust and leak proof. The pipe couplings are serrated having a well connected orifice with rubber hoses to make headers and valves air tight and provide a good pressure range of _______ from pulsing valves.

FILTER BAGS , VENTURIES & WIRE CAGES

FILTER BAGS

Fair Engineering Company is a leading provider of engineering, procurement, and construction services for pollution control systems in steel plants. Our expertise extends to the design and implementation of effective filtration solutions, including the utilization of non-woven filter bags in bag house systems. In this article, we will explore the advantages and technical aspects of non-woven filter bags, which play a crucial role in filtering out harmful dust particles and ensuring cleaner air in steel plants.

Non-woven filter bags are a key part of bag house systems used in steel plants to filter smoke and fumes, preventing the release of harmful particles into the air. Non-woven filter bags are made of a variety of different materials depending on the application, and are designed to capture and contain particulates which would otherwise be released into the environment.

When it comes to steel plants, the most common material used is polypropylene, which has excellent mechanical strength and chemical resistance.

Non-woven filter bags are designed to provide an effective seal when inserted into the bag house system, allowing for a steady and consistent flow of air.

Advantages of Non-Woven Filter Bags: Non-woven filter bags offer several advantages over traditional filter media options. These advantages include:

a) High Filtration Efficiency: Non-woven filter bags exhibit excellent filtration efficiency, enabling them to effectively capture and retain even the finest dust particles. Their fine fiber structure provides a large surface area for dust collection, resulting in superior filtration performance.

b) Increased Dust Holding Capacity: The unique structure of non-woven filter bags allows for a higher dust holding capacity compared to other filter media. This extended capacity reduces the frequency of bag replacements, resulting in cost savings and reduced downtime.

c) Enhanced Air Permeability: Non-woven filter bags are designed with controlled porosity, enabling optimal air flow while maintaining high filtration efficiency. This balance ensures efficient dust collection without sacrificing system performance.

d) Resistance to Chemicals and Moisture: Non-woven filter bags can be engineered with chemical and moisture-resistant properties. This feature enhances their durability, making them suitable for challenging operating conditions commonly encountered in steel plants.

e) Easy Maintenance and Replacement: Non-woven filter bags are typically designed for easy installation, maintenance, and replacement. Their modular nature simplifies bag house operations and reduces downtime during maintenance procedures.

Technical Aspects of Non-Woven Filter Bags: To ensure optimal performance and longevity, certain technical aspects of non-woven filter bags should be considered:

a) Material Selection: The selection of appropriate filter media material depends on the specific operating conditions, temperature range, and dust characteristics in the steel plant. Common materials used in non-woven filter bags include polyester, polypropylene, acrylic, and aramid fibers.

b) Filter Bag Construction: The construction of non-woven filter bags should be carefully designed to meet the requirements of the bag house system. Factors such as bag size, shape, and seam type play a crucial role in maintaining structural integrity and preventing leakage.

c) Surface Treatments: Surface treatments, such as singeing or calendering, can be applied to non-woven filter bags to enhance their dust cake release properties, minimize pressure drop, and improve overall filtration efficiency.

d) Anti-Static Properties: In applications where combustible dust is present, anti-static properties can be incorporated into non-woven filter bags to reduce the risk of static electricity buildup and potential ignition sources.

e) Compatibility with Cleaning Methods: Non-woven filter bags should be compatible with the cleaning method employed in the bag house system, whether it be pulse-jet, reverse-air, or shaker cleaning. Proper compatibility ensures efficient and effective cleaning cycles to maintain filter performance.

Fair Engineering used the best non-woven filter bags with an average shelf life of 2 years under full operation. We have customised the filter bags designed by our vendors to be used especially for steel plants hot metallic fumes for temperatures resistance from 120°C. to 140°C.

VENTURIES

 The venturi are attached on top of wire cage to enhance the cleaning effect. The bag house has many advantages when using a venturi system. The venturi system is an efficient and cost-effective way to clean the dust cake formed on the outside of filter bags, while providing long lasting filter bag cleaning performance.

The venturi system utilizes air velocity and air pressure to produce a venturi effect which forces the air to pass through the filter bag at a high velocity. This high velocity creates a force on the filter bag which helps contain the pollutants and prevents them from escaping into the hopper. The higher the velocity of the air, the more effective the filter bag cleaning process.

The venturi system also makes the filter bag last longer as the filter bag is not constantly being exposed to the pollutants. The filter bag lasts longer as the venturi system is constantly cleaning and purifying the air passing through it. This helps to reduce the cost of filter bag replacement as the filter bag does not need to be replaced as often. Additionally, the venturi system is much more efficient than other filtration systems as it requires less energy to operate.

WIRE CAGES 

Wire cages are also called as “Bag Supporting Cages” which are designed especially for supporting non-woven fabric filter bags with internal support system that holds the filter bags. The wire cage inside the filter bags snap fit inside the baghouse top plate. Whenever the filter bags needs cleaning the pulsing valve opens momentarily for the programmed particulate collection cycle In Pulse Jet Bag Filters.  These wire cages comes in size of 4mm thick wire with ring dia of 150mm and cage total length of 4.5 mtr to 6mtr. 

We offer bag supporting cages in various configurations like MS, GI, SS304, SS316 & SS316L with 8, 10, 12, 16 & 20 vertical wires along with horizontal ring spacing made by 3 mm, 4 mm and 5 mm wire diameter to meet various requirements of the clients. This Cages are strong enough to withstand the pressure exerted during the cycle from filter bag.

ROTARY AIR LOCK VALVES

The rotary air lock valve with geared motor is a versatile industrial component used in a variety of applications. It is a type of valve that regulates the flow of material from industrial hoppers, while allowing the material inside the hopper to be dispensed. The rotary air lock valve is a critical component for many industries that transfer dust or powder in a regulated flow, such as in steel plant air pollution control systems agricultural, pharmaceutical, and mining operations.

The rotary air lock valve consists of a cylindrical housing that contains a rotating disk. The disk contains four blades, which rotate in order to regulate the air flow and pressure inside and out of hopper. The rotating disk is connected to an external geared motor, which is used to control the speed of the disk’s rotation. This allows for precise control over the amount of material dispensed from the hopper.

The rotary air lock valve with geared motor is an efficient and effective way to transfer dust or powder from one chamber to another. It minimizes dust loss and spillage, and its precise control over material flow helps to optimize dispensing methods. The rotary air lock valve can also be used to prevent air from entering a chamber, which is essential for certain industrial processes that require a dust-free environment.

It is durable and reliable component that can be used in many applications. It is easy to install and maintain, and it is also resistant to wear and tear. It is an essential component for many industries that need to transfer dust or powder in a controlled way thereby reducing spillage of materials.

ELECTROMECHANICAL COMPONENTS

MANOMETERS 

Manometers and DP switches are important components used in bag house systems for pollution control in steel plants. These instruments are critical in ensuring that the bag house system operates effectively and efficiently, by measuring and controlling the pressure differential across the filter bags.

Manometers are devices that measure the pressure of a fluid, which in this case is the air flowing through the bag house system. They are typically used to measure the pressure drop across the bag house filters, which is the difference in pressure between the dirty air side and the clean air side of the filters. By monitoring the pressure drop, engineers can determine when the filters need to be cleaned or replaced, to maintain optimal filtration efficiency.

DP SWITCH 

DP (differential pressure) switches are devices that are used to monitor the pressure differential across the filter bags. They are typically set up to trigger an alarm or initiate a cleaning cycle when the pressure drop exceeds a certain threshold. This ensures that the bag house system is always operating within the required pressure range, which helps to maximize the life of the filter bags and maintain efficient operation of the system.

In addition to their role in maintaining system efficiency, manometers and DP switches are also important for ensuring compliance with environmental regulations. Many regulatory agencies require that bag house systems be equipped with these instruments to ensure that they are operating within specified pressure ranges and effectively removing pollutants from the air.

At Fair Engineering Company, we understand the importance of reliable and accurate instrumentation in bag house systems. That’s why we offer a wide range of manometers and DP switches, designed to meet the specific needs of steel plant applications. Our experienced team of engineers can help you select the right instruments for your system, and provide installation, calibration, and maintenance services to ensure optimal performance and compliance with regulatory requirements.