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Show The coal store capacity is about 200,000 tons of coal or one year operation. The store has walls to avoid disturbing sights from the neighbourhood. The ground is covered with mud and has its drainage to be able to control the leakage water. To transport the coal from the harbour to the store, we use lorries. From the store to the boiler house the coal is transported by a coal conveyor through normal cleaning equipment to the four coal hoppers that each can store appr. 600 tons of coal (about 50 h operation). The transport from the store to the hoppers is supervised by TV cameras from a central control room. The total capacity of the conveyor is 600 tons/hour, and the total firing capacity is about 24 tons of coal on each boiler. The total cost for the coal conversion is about 16 million dollars, 5 on firing equipment, 4 on electrostatic precipitator, 5 on coal conveyor and 1 on coal store. Increased personnel demand is about 20 people after the coal conversion, 12 on operations, 3 on coal store, 3 maintenance and 2 engineers. In the summer 1981 the boiler was commissioned without any big problems, and in September - October 1981 a delivery test was run. The measured results are presented in Picture No. 5. During the test three different types of coal were tested, and the results were very positive on both firing rate and precipitator efficiency. It was proved that the boilers could produce 240 tons of steam on pure coal firing instead of the guaranteed 120 tons/hour. The precipitator had as high efficiency as 99.99% for all the coals and stable coal flames could be maintained at low 0? concentrations. The boiler efficiency was as expected high due to the new economizer that made it possible to maintain the stack-gas temperature at 110 C. See Picture No. 6. Even the NO values were low for all three coals, even if the Russian coal x contains as much N as over 2%. Experiences From 1981 Conversion During the winter period 1981/82 we have consumed about 200,000 tons of coal. The boiler availability has been about 92%. We have been firing mainly four different coal types: Russian, Polish, Scottish and American coal with softening temperatures from 1140 C to 1500 C without any slagging problems at all. It seems that the installed sootblowers have worked 5-9 |