Technological upgrade for a greater sustainability in Tasek Corporation Behrad, Malaysia.
CTP Team support the growth and the specific needs of Ipoh Cement plant in comply with the new regulation for dust emission at the stack.
Filter Design Capacity
SWAP low pressure (cleaning system)
Capture dust emissions
Figure: The Fabric Filter in Ipoh plant of Tasek Corporation, Malaysia
Basic design data
|FILTER DESIGN CAPACITY||Am3/h||928.500|
|TOTAL FILTERING SURFACE AREA||m2||15.162|
|BAG SIZE||mm||ø152 x 12,000|
|COMPRESSED AIR CONSUMPTION (2,5 BAR)||Nm3/h||208|
|NUMBER OF BAGS PER ROW||No.||21|
|DUST CONCENTRATION AT INLET||G/nM3||60|
Scope: ESP convertion into fabric filter
FULL EP project: From Engineering to Construction and supervison activity during commissioning and start up.
Cleaning System: SWAP Technology
Start-up: Feb 2019
The request of the customer or Customer goal
We are at the beginning of 2017, when CTP Team entered the negotiations for a new challenging dedusting system for the kiln and the raw mill of Ipoh cement plant. As result of the growth in the clinker production (TPD) of Ipoh Cement plant and stricter national regulation on environment, our customer decides to implement a new technological dedusting system more efficient and that could guarantee to be compliant with the dust limit at the stack.
The customer awarded CTP team with an Engineering-Procurement (EP) contract for the new Fabric Filter. CTP Team has assisted the customer with Engineering, Procurement and has supported the customer during all the execution of the project on-site with a specialized team of site supervisor, taking care of the commissioning and training activity of the customer’s maintenance team.
The technological choice 3-in-1.
The original dedusting system has been revolutionized by an innovative Fabric Filter designed with bags 12m long, equipped with SWAP technology (Sonic Wave Acceleration Pulse) as cleaning system and with a completely-different manifold layout. The existing gas process of kiln #3 and raw mill was composed by two independent dedusting systems: three ESPs filters in parallel for the raw mill’s exhaust gas and one independent electrostatic precipitator dedicated to the dedusting of the hot gas coming from the preheater.
CTP Team has designed a new dedusting system which gather both the streams from raw mill and preheater in one upgraded single unit of bag filter. In addition the new single unit should be located on the existing support structure of the sole original electrostatic precipitator of the preheater.
The challenging design: merging structural limits with dedusting needs
In brief , we have studied and engineered a different gas distribution in the Fabric Filter and increased the length of bags up to 12m long.
The typical bag filter configuration with central manifold and bags 10m long was unfortunately not enough to guarantee the proper filtration of the gas volume of 900,000 Am3/h. The bigger design then needed four additional hoppers and many relevant support columns.
In the final solution we have replaced the central manifold with two different gas inlet ducts positioned along the two longitudinal sides of the Fabric Filter, then we have increased the length of the bags up to 12m, organized in 126 rows joined a total number of 2.646 bags.
In the figure 1 and 2 are shown the original drawing of the existing ESP filter and the comparison between the two Fabric Filter configurations with 10 or 12m bag length.
In-house engineering and design capacity and the challenge of the brown field
CTP Team engineering capacity has been expressed in the design of this innovative dedusting system which merge the dedusting need with the strict limits imposed by the customer in terms of existing structures and gas emissions at the stack.
The filter design is the result of the merge of different factors, for example: the gas volume together with the air-to-cloth ratio. The gas distribution plays an important role and it is performed in a way to reduce as far as possible the dust reaching the bags and, at the same time, to uniform the gas distribution along all the bags.
A Computational Fluid Dynamics (CFD) study of the gas flow has been carried out in order to reach a homogeneous gas distribution inside the filter.
We have completely kept and reused the existing ESP support structure and modified the gas inlet and outlet ducts according to the challenging configuration of the manifold of the new Fabric Filter. Furthermore, we have supplied all the key components of the filter, filtering sets and casing, the filter is equipped with our innovative bag cleaning system based on SWAP Technology and a penthouse on top for weather protection equipped with maintenance hoists. Then, there is a new dust discharge and conveying system. The filter is equipped with an electric board for the operation controls, the maintenance activity can be done online avoiding to switch off the filter. A fresh air dilution dampers protect the bags from peaks of temperature and a new I.D. fan deliver the clean gas stream to the existing stack.
Critical points to be faced
- Smart erection in existing structure
One of the major complexities of the project has been to fit the new fabric filter on the existing ESP supports keeping the existing footprint without any extension due to lack of space in this area. Thanks to CTP Team knowledge and experience we were able to fully integrate the new Fabric Filter in the existing plant without affecting production parameters.
- Efficient cleaning system for bags up to 12 m long
In order to cleaning efficiently the bags inside the filter, we have suggested and installed our efficient Sonic Wave Acceleration Pulse (SWAP) technology. This proven low pressure technology for cleaning bags key-components of Fabric Filters consists in a sonic wave which travels all along the length of the bag at a velocity approx Mach 1. This technology keeps the full efficiency with bags up to 12m length and up to 30 bags in one single row, working online without the necessity to install dampers and isolate the compartment during the cleaning cycle.
This technology is the winning alternative to the traditional high pressure cleaning system with Venturi.
PLUS of SWAP Technology:
- Best efficiency in cleaning of long bags
- Keep constant the pressure drops over time
- Reduced consumption of compressed air thanks to the quick opening of the piston valves
- Modular assembly
- Shorter erection time
Tasek project and results
The Fabric Filter designed with bags 12m long and equipped with the SWAP technology grant the efficient cleaning of all 2.646 bags, with one single shot the piston valve cleans 21 bags per row. With a total filtering surface of 15.162 m2 the Fabric Filter grant the treatment of 928.500 Am3/h gas volume at inlet. Other details of the Basic design data of the Fabric Filter are listed below in table 1.
The targets related to the performances of the Fabric Filter have been fully achieved and even lower than expected. The registered dust emission at the stack is lower than 5 mg/Nm3 and the total filter pressure drop is 10 mbar.
In short, the improvements provided with the new Fabric Filter have been:
- Top efficiency of bag cleaning system now performing the CTP SWAP technology by means of sonic piston valves applied with 12m long bags.
- Full control of the cleaning system including the opening time regulation of the cleaning valve at very low levels.
- Dedicated control board with full cleaning process control.
- Advanced calibration of technological parameters for optimal cleaning air working pressure, reduced pressure drop and minimized energy consumption
A continuous technological improvement allows CTP Team to match efficiency and maximum energy saving in an innovative emission control system. With our experience and deep knowledge of the site activity we have support our customer during the huge preassembling work before kiln stoppage, precise scheduling of all site activities, was the key to achieving this significant result.