Making an incinerator is not a simple and straight forward affair.  This may seem like a profound statement, but it is true.  Making an incinerator is quite complex because the design has to consider factors some of which are variable and not definitive, by making allowances, before arriving at a design that would do the job.

The following parameters have to be considered while designing an incinerator:

•                 Calorific value of waste

•                 Temperatures required

•                 Heat conductivity of refractory

•                 The choice of refractory

•                 Type of scrubbing

•                 Type of loading

•                 Type of de-ashing

•                 Heat mass balance

•                 Lifetime of refractory

•                 Lifetime of machine

•                 Emission requirements

•                 Maintainability of various components of the incinerator

•                 Plot plan

•                 Final configuration

Of the above, the critical parameters are the heat mass balance and design for maintainability. Heat mass balance is prepared, using customized software, provided the inputs are accurate.

Maintainability of various components/sub-assemblies of the incinerator has to be seriously considered from the point of view of accessibility and operation of the equipment.  For this purpose, 3D modeling is used and approved by the client before proceeding with the work.

The variable factors are of course, the waste itself and its configuration and hence calorific value, refractory and fuel characteristics, etc.

It is very important to achieve the emission requirements which, of course, are based on combustion efficiency and waste characteristics.

Due to the very exhaustive work and calculations involved, it makes it expensive for the incinerator manufacturer to prepare detailed design documents incorporating all the possible answers to the above questions before even taking up the work of preparing an offer.

For this reason, depending on the plant size, many overseas engineering companies charge a fee to their customer for preliminary incinerator pre-engineering work, leading to an offer.  The work involves many design calculations and software and is quite elaborate with many man hours spent, to come up with an acceptable solution.

Once the contract is finalized, incinerator PFD and P&ID and GA drawings are made and sent to the client for his approval before detailed engineering is taken up.

In India, however, pre-engineering fee is generally not accepted by majority of the users.  They expect the manufacturer to prepare a basic design at his own cost based on available data.  It does not matter, if the bidder does not get the contract.  In practice, overseas buyers shortlist either engineering companies who do the design or shortlist incinerator manufacturers who have design capabilities, after qualifying them.

In India, the incinerator manufacturer has to put in efforts, spend time and money to make an offer and if and when he wins the contract, he has to do detailed engineering. This means both basic engineering and detailed engineering costs are to be absorbed by him.

Nevertheless, in spite of the variable factors being considered for design, there are many `if`s and `but`s because the buyer expects the incinerator manufacturer to take responsibility considering the worst case scenario while designing the system without however over-designing it.

In spite of these predicaments,  the incinerator manufacturer with design capabilities takes up the job with a smile, because he treats the whole matter as a challenge, because depending on the quality of his design and the quality of his product,  it could become rewarding to him both in the short run and long run.  What is more gratifying is when all the painstaking efforts have produced a good performance from the incinerator, it makes everyone happy, particularly leading to CUSTOMER SATISFACTION.

More information on how to select an incinerator here – Selection of an Incinerator.