Let me say this by way of introduction: these publications\nare for the engineer and supervisor who are responsible for small scale steam\nplant operations. His steam boiler fires pea coal and produces less than 30\ntons of saturated steam per hour at less than 20 bar pressure. These\nlimitations exist because of the boiler configuration \u2013 it is a chain grate\nfire tube boiler, consisting of one or two furnace flues.<\/p>\n\n\n\n
He probably has been relying on the perceptions,\nimpressions and coaching of his predecessors to make him fit for a very\nresponsible position. He may even have completed boiler operators and boiler\nmaintenance courses, but lately the boiler scene has changed dramatically in\nterms of cost saving demands on management, deteriorating coal qualities and\nmore stringent environmental legislation. His training and experience is\nincreasingly letting him down in understanding how to tackle these challenges\nfrom first principles. As a matter of fact, he may have an electrical\nbackground and inherited the boiler plant as part of a company restructure. <\/p>\n\n\n\n
Don\u2019t feel alone! If this was not quite your experience,\nit definitely was mine. I faced my first boiler in the dairy industry in 1983.\nMy mentor was the regional boiler supervisor and he ran each boiler house under\nhis supervision like a military operation. Operators were coached, not trained.\nThey became programmed robots, with only a vague idea why they were performing\nthe actions they were instructed to perform. <\/p>\n\n\n\n
After close to 40 years in the boiler and combustion industry I have learned and experienced sufficiently much to know that my original mentor had it wrong in many respects, primarily because little of what he believed was based on sound engineering principles. After all, coal was still plentiful, cheap and of good quality in those days with little focus on the efficiency of steam production.<\/p>\n\n\n\n
Even today it is not uncommon to find engineering and operating\nstaff partially or totally ignorant of the scientific principles behind\ncombustion, boiler efficiency and boiler control, not to mention\nthe characteristics of coal (solid fuels) and its impact on the\ncombustion process. And quite often the little bit they do know is based on\ngeneral opinion, hear-say and their own interpretation of their experiences in\nabsence of proper education and guidance. <\/p>\n\n\n\n
Thus the intention to publish a series of Boiler Bits was born. The name\nI selected for these publications already implies that they will be short\npieces dealing with all kinds of boiler related matters. No lengthy scientific dissertations,\nmathematical formulas and academic papers though; I will rather aim to explain\nscientific principles in a logical and easy to understand way so that everyone\ninvolved with steam plant operations will be able to grasp why their plant is\nand performs the way it does. <\/p>\n\n\n\n
In the South African context I believe there is need for practical\nguidelines on understanding and practicing the firing of pea coal in horizontal\npackaged fire tube boilers, although most of the principles discussed herein\nequally apply to water tube boilers and boilers firing liquid, gaseous, biomass\nor pulverized coal fuels. My attempts at finding specific information\nregarding firing pea coal on traveling grate boilers on the internet was rather\ndisappointing \u2013 there are lots of material dealing with fire tube boilers, and\nfiring of pulverized and atomized (gas and oil) fuels, but it seems that pea\ncoal firing boilers receive far less than its fair share of attention. Where\npea coal is mentioned, it refers to the properties of northern hemisphere coal.\nBasically nothing on small fire tube chain grate stokers firing local (South\nAfrican) bituminous coal.<\/p>\n\n\n\n
This also convinced me that there must be a need for elementary material which provides an understanding at grass roots level of all the elements and influences making up a combustion system, how these elements interact and influence one another, as well as the steam generation process as a whole; and finally how the understanding of basic principles crystallizes out in the practice of optimized steam production, i.e. how to apply scientific principles to arrive at producing steam at the lowest total cost* per kg or ton. I hope to succeed in painting the overall combustion picture in a way that will enable readers to grasp and internalize it, and to apply it towards conserving energy, reducing pollution and protecting steam plant assets. <\/p>\n\n\n\n
In my opinion many of the problems experienced in the boiler house\noriginate much higher up in the organization, at management level. I once came\nacross the following definitions pertaining to \u201cmanagement\u201d which I consider\nappropriate: <\/p>\n\n\n\n