STORAGE AND FEEDING OF HOG FUEL - A NEW APPROACH

摘要

A common problem with fibrous material is bridging in storage bins. An extensive research project was done on biomass materials, involving laboratory and pilot-scale work. Inappropriate bin geometry and poor discharge feeder design were identified as the two main causes of the flow problems.A surprising conclusion of the research was that a positive slope mass flow hopper with a reasonable outlet dimension can be used. Common practice is to use negative slope bins with large outlet dimensions.The discharge feeder was found to be the main cause of the flow problems. Most feeders tend to draw material mainly from the rear of the bin, and tend to pack material against the front wall - this is usually accompanied by excessive power requirements.The Non-Consolidating ('Moving Hole') Feeder which avoids the above problems, was developed.. The feeder essentially consists of one or more slots between deck sections which traverse back and forth without any friction between the stored material and the feeder deck. The feeder does not pack material in the bin, and permits reliable, first in first out flow even for very difficult flowing materials. Other advantages of the feeder system are low power requirements.Five hog fuel boilers are currently using this technology successfully - two of the installations involved retrofitting to solve severe 'hang-ups' . The largest installation of the mass flow bin for wood waste is an outdoor bin with a capacity of 17,000 ft~3.