Multi-level solid fuel drying system

Abstract

The invention relates to a multi-level solid fuel drying system. The multi-level solid fuel drying system comprises a horizontal fluidized bed, a filter and a heating box, wherein the horizontal fluidized bed, the filter and the heating box are connected with one another; the horizontal fluidized bed is divided into fluidizing chambers of different sections by baffles; a heat exchanger is arranged in each fluidizing chamber; the horizontal fluidized bed takes overheat steam as fluidized gas and is used for carrying moisture, and takes multi-level saturated or nearly saturated steam with 105-300 DEG C as heating steam; moisture-containing fuel flows through the fluidizing chambers in sequence under a fluidizing state and is heated by the heat exchangers immersed in bed particles for layered drying or temperature adjustment, and meanwhile, the heating steam passing through the heat exchangers of different sections and the overheat steam passing through the fluidized bed are enabled to pass through the heating box for heat integration; and the step utilization of heat energy in a drying process is realized while the integrated heat is recovered and the overheat steam is recycled. Compared with the prior art, the multi-level solid fuel drying system provided by the invention has the advantages of returning and mixing of smaller fluidized bed drying particles and step utilization of drying heat source and the like.

Description

technical field [0001] The invention relates to a multi-stage solid fuel drying system, specifically a horizontal fluidized bed with a multi-stage heat exchanger to carry out segmental drying of fuels such as coal and biomass with high water content, and can realize A device for cascaded utilization of thermal energy. Background technique [0002] China is rich in coal and poor in oil and gas, and the utilization of coal has always been in the main position in my country's primary energy consumption. In my country, a considerable part of coal is lignite with high water content. In 2009, the proven reserves reached 130 billion tons, accounting for 13% of the country's total coal reserves. With the continuous increase of my country's demand for energy and the excessive exploitation of high-rank coal such as bituminous coal, the development and utilization of lignite will become more and more important. The high water content of lignite not only reduces the calorific value an...

AI Technical Summary

Problems solved by technology

But the disadvantage is that the particles in the fluidized bed are seriously back-mixed, and the product has the problem of uneven water content.

Another limitation of the steam fluidized bed is that because the lignite is heated by a single heat source in the fluidized bed, the heat utilization rate is low, and the low-grade heat source cannot be directly utilized

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