Airpreheaters Baskets

Air Preheater Baskets are a compact arrangement of profiled metal sheets placed in the Air Preheater rotor in two or more layers and plays the most important role in the process of heat recovery. The bottom layer, or the cold end layer, is where the air enters and the flue gases are discharged, and is therefore, subjected to severe corrosion due to acid dew point. The Material of Construction and the Profile design of the Heating Elements depends on the operating conditions, quality and type of fuel, etc.

Today IMECO Limited is the largest manufacturer of Air Preheater Baskets in India and has successfully executed orders for various organizations including NTPC Limited, various state Electricity Boards, Captive Power Plants of various industries including Steel, Fertilizers, Smelters, Refineries etc. In 2000, Imeco commenced its export activities for Air Preheater Baskets and has been successful in its endeavor.

Today IMECO is a leading name in the market for Regenerative Air Preheater Heating Element Baskets. The Company offers its services for all types of Air Preheaters in the market across the world. The elements are generally manufactured in Corten Steel for Cold End Baskets and in Carbon Steel for Hot/Hot Intermediate End Baskets. The thickness of the Elements ranges from 0.45mm to 1.6mm and depth up to 1500mm. The company is equipped to supply the standard element profiles like Double Undulated (DU), Corrugated Undulated (CU), Corrugated Flat (CF), Notched Flat (NF) etc of varying sizes. If any special profiles are required by individual buyers, IMECO is ready to customize them. The standard profile of the Heating Elements are shown in the Diagram alongside.

If required, the elements can also be supplied in smaller bundles for ease of handling. While designing/manufacturing of the custom built Heating elements, the following facts are taken into consideration.

  • Higher Thermal Efficiency
  • Lower pressure Loss
  • Solid Construction
  • Easy Assembly and Dismantling
  • Higher Resistance against corrosion
  • Easy Access for cleaning
  • High stability for washing under Pressure
  • Reliability

Heating Elements are of various types and are designed to perform under varied stringent operating conditions. Thus, the Raw Materials are properly selected keeping this in view. Normally the Heating Elements are made from the following material:

  • Carbon Steel
  • Corten Steel (Cold Rolled Low Alloy Steel)
  • Stainless Steel
  • Enamel Coated Steel
  • Water Dew Point resistant Steel

To meet the multiple requirements of the valued customers, IMECO provides services for standard as well as special containment designs. Generally the containers are available in Mild Steel or Corten Steel with stiffening Bars for extra rigidity.

Air Preheater Baskets are manufactured at the Kharagpur Works of Imeco on automatic Rolling Lines with capacity of 1500mm width. The following facilities are available in the factory: -

  • Four Cold Forming Rolling lines for manufacture of Heating Elements
  • Slitting machine for slitting of steel coils to required element width
  • Material handling equipments for movement of heavy coils and the Air Preheater Baskets
  • Enameling line for enamel coating on Heating Elements
  • Hydraulic Packing systems for Air Preheater Baskets

The above is only indicative and not exhaustive. The entire manufacturing process is targeted towards providing for quality to our clients for which Imeco follows a strict quality control system shown in the "Production and Inspection Flowchart" below.

The Air Preheater Baskets are properly treated with Anti Corrosive Oils for better shelf life. All Baskets are plastic wrapped and palletized prior to loading.

Quality Assurance is the key concern of IMECO and its Quality assurance plays a dominant role throughout manufacture. Raw Materials are sourced from reputed and established manufacturers and Material Test Certificates are invariably furnished along with the supplies. Test check of the Materials are carried out in-house as well as with independent Test Laboratories. During manufacture continuous inspection is carried out to ensure that the Elements are made with required tolerances. After completion of manufacture detailed inspection is carried on by a team of engineers, if required, along with the engineers of the customers.

IMECO also offers third party inspection to the customers who may appoint various inspection agencies like Lloyds, SGS, etc.

On receipt of an order, IMECO immediately furnishes the Quality Assurance Plan to the Customer for approval before start of manufacture. A typical copy of the Quality Plan is shown here for ready reference.

IMECO follows a strict quality control system

Quality Assurance Plan for (Item Details)
Customer Puchase Order No: Drawing Number :
Sl no. Components & Operation Characteristics Class Type of Check Quantum of Check Reference Documents Acceptance Standard Format of Record Agency Remarks
 1. Raw Material Chemical Analysis Major Chemical Analysis 1 Test Piece As per Standard As per Standard Test Certificate Approved Lab. Approved Laboratory  
Physical Analysis Physical Analysis
 2. In Process Visual & Dimensional Major Dimensional Check 5% As per Drawing As per Drawing Inspection Report Customer representative or authorized inspection agency of customer’s choice.  
 3. Final Inspection Visual & Dimensional Major Dimensional Check 5% As Per Drawing As per Drawing Inspection Report Customer representative or authorized inspection agency of customer’s choice.  

Imeco has a prominent share of the one million MW strong Indian Power Sector. It has also made its impact in the International market. Quality, delivery and price are hallmarks of Imeco.

Imeco has a strong belief that even the best can be bettered. Therefore, IMECO always looks forward for receiving feedback from its customers on the products and services rendered to them, for further improving the services. Some of the satisfied customers have issued certificates in respect of products supplied and services rendered.

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