WASTE FIRED STEAM BOILERS

Transcription

1 Steam Boilers WASTE FIRED STEAM BOILERS Adviesbureau de Koster v.o.f Page 1

2 Preface This book contains information of a general nature as well as a description of a random installation. The first chapter is specifically intended for those who are not familiar with waste processing and waste incineration and is of an introductory nature. The other chapters all start with an introductory part followed by information on the actual installation itself, where possible. Some chapters also contain lots of (model) calculations. For enthusiasts we have also included some very comprehensive model calculations. There is also a section on thermodynamics, which includes the incineration diagram by Professor A.J. Terlinde together with a practical application. As some statutory rules have changed and we have received various comments from readers since the book was first published, we felt it was time to publish a revised edition. The author is open to constructive criticism that can help improve the usefulness of this book. Ing. A.J. de Koster Hoofdplaat, June Waste Fired Steam Boilers Adviesbureau de Koster v.o.f. Dorpsstraat AL Hoofdplaat The Netherlands Tel (0) ISBN info@martechopleidingen.nl First edition June 2010 Original title: Afvalgestookte Stoomketels. Original Dutch language edition published by Adviesbureau de Koster. Copyright 2010, 2009, 2004 by Adviesbureau de Koster Translated by: Intertext Service Adviesbureau de Koster, Dorpsstraat 5, 4513 AL Hoofdplaat. All rights reserved. No part of this publication may be reproduced, stored in a database or retrieval system, or published, in any form or by any means, electronically, mechanically, by print, photoprint, recording or otherwise without prior written permission from the publisher. This also applies to the full or partial adaptation of this publication. Although this book has been compiled with the greatest care, we cannot accept any liability for damage arising as a result of possible errors and / or omissions in this book. Page

3 Contents 1.0 Introduction Difference between fossil fuels and waste General waste incineration Extreme situations Consequences of incineration Recap of incineration The Boiler, general Construction of the boiler The design of the boiler The steam pressure and steam temperature Chlorine is bad for energetic efficiency Quality of residues Lower efficiency Developments in the incineration process The steam boiler, general remarks The steam boiler with four tubes The furnace The reverse acting grate Roller grate incinerators Waste incinerator with reverse acting grate The resistance of the waste and the grate The stoking diagram or furnace diagram Flue gas re-circulation The natural circulation in the boiler Introduction The origin of natural circulation Some general remarks Spontaneous evaporation Evaporation prevention or evaporation delay Some general considerations regarding circulation The flow of circulation from stoking the boiler to operating pressure Example of circulation calculation The Deaerator How the deaerator works, in general The Stork feed water deaerator Details of a random deaerator Statutory regulations applicable to the deaerator Theoretic view of the deaerator Model calculation Deaerator The air quantities required Upper calorific value and lower calorific value Upper calorific value The Lower Calorific Value Page 3

4 7.0 Corrosion Low temperature corrosion and limiting the feed water entry temperature at the economizer High Temperature Corrosion, HTC Corrosion of the super-heater pipes Corrosion of 1 st shaft pipes Measures against high temperature corrosion Evaporator bundles Super-heaters Adding components to the fuel Results of the additives Protective layers in high temperature areas Corrosion preventive effects of the protective layers Caustic corrosion Chlorine corrosion Some general remarks The Boiler efficiency History Improving the efficiency The steam boiler Improvement of the efficiency Theoretical consideration of boiler efficiency Introduction to heat transfer Conduction Conduction through a thick walled pipe Flow (Convection) Derivation of the convection formula The heat exchanger Heat transfer calculations Radiation Nitrogen oxides Flame temperature reduction Carbon monoxide Refractory The combustion diagram by Prof. A.J. Terlinde Changing the load with a constant air factor Increasing the air factor at 70% load Increasing the air factor at full load Demineralization Introduction Cation CO 2 extraction tower Anion exchanger Regeneration 147 Page

5 14.0 Boiler water treatment The quality of the boiler water and the significance of this for the steam installation Deposits on the water side Preventing boiler scale Corrosion on the water and steam side Oxygen corrosion Acid corrosion Alkaline corrosion Metal brittleness Influence of ph on corrosion The concept of carry-over Condensate system Top-up water Water treatment Top-up water Condensate Boiler water Inspection of the water quality Top-up water inspection Inspection of condensate Boiler water inspection Measures to be taken in the event of abnormalities Inconel General Use and properties Frequently used terms and definitions Formula sheet Quantities and units Page 5