• Ensuring uniform flow in the filter
• Reduction of filter operational pressure loss
• Less energy consumption
• Longer bag life
• Low equipment investment costs
• Low emission values
• To prevent dust accumulation and blockage formation in filters
• To prevent wear on the Filter Housing
• To prevent rapid wear on equipment such as fans, to extend the service life
• Modernization of equipment with minimum investment to meet the increase in production

Reducing the cost of Operation and Maintenance

The need for increased production and lower emission values creates the need to review, renew and strengthen existing dedusting systems. These modernization works can be done with technological solutions by providing significant savings with the cost-effective works we offer.

Non-uniform flow in the filter increases the filter operating pressure difference and increases the energy consumption of the filter fan after the filter. In addition, non-uniform flow patterns reduce the lifetime of expensive filter bags. By ensuring uniform flow distribution, less energy consumption and long bag life can be achieved.

Stages of Retrofit for Bag Filters

Filter Bag Failures

Burst Issue on the Bag at the top side

Problem

• Filter bags burst from the top side

Possible Cause of the Problem

• Centering problem of the Cleaning air nozzle
• There is dust in the cleaning side (top boxes)
• Abrasions on the cleaning pipe and nozzles

Possible Solutions

• Control the centering of the cleaning nozzles
• Replacement of cleaning pipe and nozzles

How does the problem occur

• Any single bag is burst
• Dust escapes from the burst bag into the cleaning pipes
• Nozzle holes and venturies are damages
• Shooting angle changes with dust abrasion
• Abrasive dust into cleaning pipe hits venturies
• After venturies damages many bags burst happen too fast

Solution

• Prevention of venturies damages with new easy-change nozzle
• Reducing bags bursting.
• Preventing the problem from occurring by using a burst bag detector
• Energy savings with reduced compressed air requirement

Burst Issue on the Bag at the bottom side & cylindrical side

Problem

• Filter bags burst from the bottom side & cylindrical side

Possible Causes of the Problem

• Poor filter design
• High can velocity
• High Approach Velocity
• High Transversal Velocity
• Poor flow distribution inside the filter
• Incorrect design of the filter inlet pipeline

Possible Solutions

• Cfd Analysis to find the cause of the bags burst

Retrofit Project Example on Bag Filter

Mill Process Bag Filter CFD Analyses &Flow Optimization

The aim of this study is to investigate the inlet region and inside of the filter flow.
Filter interior design should be done correctly.

Inlet and outlet pipeline design is as important as the filter interior design. Because poor inlet pipeline design changes the filter performance.

Problems of the Poor Inlet Pipeline Design

• Irregular air flow in filter and some of the bags not working properly
• High energy consumption with increased system resistance
• Corrosion occurs on filters casing and bags in irregular flow areas
• Filter gas flow : 1.100.000 m3/h actual
• Gas density : 0,850 kg/m3
• Solver : ANSYS CFX

Existing Filter Design Problems

• Irregular air flow inlet pipeline
• Big swirl in filter inlet
• Irregular flow distribution on manifolds
• Big swirl in filter outlet and filter fan performance losses

Existing Filter Design Problems

• Irregular flow velocity under surface of bags

Design Revisions

• Guide vanes are added to the inlet ducting
• Straightener baffles are added in outlet section

The aim of this study is to investigate the inlet line and inside of the converted bag filter flow.

Inlet and outlet design is as important as the filter interior design. Because poor inlet design changes the filter performance.

• Filter gas flow : 603 000 m3/h actual
• Gas density : 0,735 kg/m3
• Solver : ANSYS CFX

Fan performance loss is prevented by output pipeline correction ( Pleasesee AMCA 201-02 / System inlet effectclause)

Bag Filter structural analyses / Large deflection problem

Calsined Clay Jet Pulse Filter Flow Optimization

The post Bag Filter Renewal/Retrofitting Works first appeared on Alfer Mühendislik.

Why is Retrofit Work Performed on Fans?

• Achieving Energy Savings by Increasing Fan Efficiency
• Saving Energy with the Right Operating Point
• To Prevent Vibration, Increase Due to Powder Adhesion
• Reducing Stoppages Due to Dust Sticking
• To prevent rapid wear on the Impeller (Rotor) and Volute
• Eliminating Capacity Inadequacy
• Modernization and renewal of existing fans with low investment cost
• Extending product service life
• Reduction of noise level
• Ensuring increase in production volume
• Reduction of Operating and Maintenance costs
• Ensuring compliance with legal requirements

Stages of Fan Retrofit

Decision for a Complete Fan or Only Rotor Design

To decide whether a new rotor can be designed inside of existing casing

Existing casing evaluated considering new rotor design based on requested capacity values.

If casing condition is in compliance, only rotor gets designed. If not, complete fan offered

New Rotor & Fan Design Stage

Conceptual Design

With ALFER’s design correlations interactive fan design software

Aerodynamic Design / CFD / Capacity and Flow Control

Flow of the Inlet Box and fan casing

Flow of the blade passage and casing

Aerodynamic Design / CFD Analysis

Fan CFD Analyses / Velocitydistrubition

Mechanical Design / Stress & Deflection Control

Mechanical Design / Resonance Control

Retrofit Fan Design Example

Low Specific Speed (nq24) Kiln ID Fan

Definition of the Problem ?

• Vibration increase Due to Dust Accumulation
• Downtime every single month
• Loss of Production
• Decreasing lifetime of bearing housing and bearing units

What are the Precautions in the new design ?

• Total Flow Surface Optimization by designing a star type Back Plate
• Defining a New Operation Point and Flow Optimization
• Changing Impeller Radius and Blade Passage Flow Optimization
• Blade Leading Edge Optimization for Specific Speed
• Design and optimization of the flow velocity distribution in the casing and impeller
• Prevention of Flow separation in casing and airborne dust in casing
• Increasing casing efficiency with Trapozoid shape casings

Aerodynamic Design / CFD Analysis

Mechanical Design/ Stress & Resonance Control

Project-Manufacturing- Assembly

Result?

• Vibration level became extremely low
• Stoppage Time Due to Dust Accumulation is over
• 166 kWh %16 energy saving

Low specific speed/ Serbia Booster Fan Design

Possible Problem Occurrences?

• Low specific speed(Nq24)
• High Dust
• Long blades necessity

Result?

• No vibration due to dust adhesion.
• No dust related stoppage problems.

Raw Mill Filter Fan Rotor Design

Possible Problem Occurrences?

• Impeller for existing casing
• Capacity Increase

Results?

• Desired Capacity provided.
• Targeted efficieny achieved

Raw Mill Filter Fan Design

Possible Problem Occurences ?

• Work on the Beams in the Intermediate Floor
• Low Intermediate Floor Height
• High Efficiency and Small Area
• The Resonance Problem of the Chassis on the Spring

Results?

• Capacity achieved.
• High Efficiency achieved
• No Vibration Problems
• No Resonance Issues

Klinker Cooler Filter Fan Rotor Design

Possible Problem Occurences ?

• Impeller for existing casing
• Requested Efficiency Increase

Results?

• High Efficiency achieved
• No vibration problems.

Kiln ID Fan Rotor Design

Possible Problem Occurrences ?

• Lack of Capacity Increasee
• Lack of Requested Efficiency

Results?

• Inlet Box Revision
• Requested capacity point reached.
• No Vibration Issue
• No Resonance Issue

Cement Ø3380 Kiln ID Fan Rotor

Possible Problem Occurrences?

• Existing conical fan casing shape
• Lack of Required Capacity
• Required High Efficiency
• High Temperature (460 C) durability issues

Results?

• Requested capacity achieved.
• No Vibration issue
• No Resonance Issue
• No mechanical problem from high temperature

Low specific speed (nq30) Kiln ID Fan Design

Possible Problem Occurences ?

• Required High Efficiency
• Different operation Point
• Long blades necessity
• Low specific Speed(Nq30)
• Dust accumulation

Results?

• High Efficiency provided
• No Vibration issue
• No Resonance Issue
• No dust related stoppage problems

Kiln ID Fan Dust Abrasion Analysis

The post Fan Renovatıon/Retrofıt (Retrofıt) first appeared on Alfer Mühendislik.