Steam fluid bed drying device and steam fluid bed drying method

Abstract

The invention relates o a steam fluid bed drying device and a steam fluid bed drying method. Crushed coal is fluidized at the bottom of a dryer (6) under the action of blown in steam and is subjected to heat exchange with a heat exchange pipe inside the dryer (6); water steam from drying of the coal is separated into two ways: the water steam in one way enters an ejector (11) via an adjusting air valve (10), and is recycled to a drying tube in the dryer (6) to supply heat energy for drying after being subjected to temperature and pressure rising under an injection action of medium pressure steam; the water steam in the other way is pressurized by a fan (12), recycled to the bottom of the dryer (6) and blown into raw coal to supply fluidizing power. The steam fluid bed drying device and the steam fluid bed drying method are applicable to drying of low-rank coal like brown coal and have the advantages of energy conservation, environment friendliness and the like.

Description

technical field [0001] The invention relates to a steam fluidized bed drying device and a drying method. The device and method are especially suitable for drying low-rank coal such as lignite. Background technique [0002] Low-rank coal refers to coal with a low degree of metamorphism, including lignite, long-flame coal, non-caking coal, and weakly caking coal, among which lignite accounts for a large proportion. The geological reserves of lignite in the world are about 4 According to statistics at the end of the last century, my country has proven lignite reserves of 130 billion tons, accounting for about 13% of the country's total coal reserves. Lignite is the initial product of peat deposits that are dehydrated and compacted into organic biorocks. It is named for its brown or dark brown appearance. Lignite has the characteristics of high volatile matter, high moisture, high ash content, low calorific value, and low ash melting point, which have a great adverse effect on i...

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Problems solved by technology

This kind of process has low energy consumption due to the recovery of the moisture dried from the coal, but it is difficult to manufacture the heat pump used for steam recovery, and there is no application at home and abroad.

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