Apparatus for drying coal using reheat steam

Abstract

The present comprises: a first coal dryer; a second coal dryer; and a third dryer, by removing moisture remaining inside and outside of coal, which is used for fueling thermal power plants, in the multiple coal dryers using reheat steam at a high temperature, incomplete combustion of coal can be prevented, thereby enhancing heat capacity of the coal, minimizing release of pollutants, preventing corrosion and enhancing the durability of a system, reducing the rate of spontaneous combustion due to reduced moisture, improving crushing efficiency of a coal pulverizer and heat distribution of a power boiler when coal is combusted, resolving the issue of clogging of a moving pathway when coal is transported, and improving coal supply stability by increasing utilization of low-quality coal for which demand is low. Furthermore, the following advantages can be provided: use of low heat capacity coal which is more affordable than high heat capacity coal; savings in fuel cost and manufacturing cost by reduced coal importation; reduction of waste, pollutants, and carbon dioxide generated from exhaust gas by relative reduction of coal consumption, and the advantages of replacement of foreign technology and exportation of equipment to foreign markets could be anticipated.

1 . An apparatus for drying coal using preheat steam, the apparatus comprising:
 a first coal dryer in which a pair of first drive sprockets and a pair of first driven sprockets are spaced apart from each other at a constant distance and are fastened to each other by first chains, a plurality of first transport plates is hinged between the first chains, a pair of first guide rails that horizontally supports the first transport plates is installed below an upper second chain connected between the first drive sprockets and the first driven sprockets, a pair of second guide rails that horizontally supports the first transport plates is installed below a lower first chain connected between the first drive sprockets and the first driven sprockets, a first steam chamber that injects a reheat steam supplied from a reheater is installed below the upper first chain, a second steam chamber that injects the reheat steam supplied from the reheater is installed below the lower first chain, a first exhaust chamber that collects an exhaust gas is installed above the upper first chain, and a second exhaust chamber that collects the exhaust gas is installed above the lower first chain;   a second coal dryer in which a pair of second drive sprockets and a pair of second driven sprockets are spaced apart from each other at a constant distance and are fastened to each other by second chains, a plurality of second transport plates are hinged between the second chains, a pair of third guide rails that horizontally supports the second transport plates is installed below an upper second chain connected between the second drive sprockets and the second driven sprockets, a pair of fourth guide rails that horizontally supports the second transport plates is installed below a lower second chain connected between the second drive sprockets and the second driven sprockets, a third steam chamber that injects a reheat steam supplied from a reheater is installed below the upper second chain, a fourth steam chamber that injects the reheat steam supplied from the reheater is installed below the lower second chain, a third exhaust chamber that collects an exhaust gas is installed above the upper second chain, and a fourth exhaust chamber that collects the exhaust gas is installed above the lower chain; and   a third coal dryer which is installed below the second coal dryer to naturally dry the coal at room temperature, while transporting the coal dried by the reheat steam,   wherein the coal primarily dried in the first coal dryer is charged to the second coal dryer to be secondarily dried.   
     
     
         2 . The apparatus of  claim 1 , wherein a steam supply pipe that supplies the reheat steam from the reheater is connected to each of the first steam chamber through the fourth steam chamber, and a gas discharge pipe that discharges the exhaust gas is connected to each of the first exhaust gas chamber through the fourth exhaust gas chamber. 
     
     
         3 . The apparatus of  claim 1 , wherein the first steam chamber through the fourth steam chamber and the first exhaust gas chamber through the fourth gas chamber are partitioned into plural numbers. 
     
     
         4 . The apparatus of  claim 1 , wherein the first transport plate is hinged to the first chain by being deflected, the second transport plate is hinged to the second chain by being deflected, a plurality of through-holes are formed in each of the first transport plate and the second transport plate, and a punching ratio of each through-hole compared to an total area of the first transport plate and the second transport plate is 10 to 15%. 
     
     
         5 . The apparatus of  claim 1 , wherein a guide bar is installed below each of the first driven sprocket and the second driven sprocket. 
     
     
         6 . The apparatus of  claim 1 , wherein each of the first drive sprocket and second drive sprocket is connected so that rotational power generated from the drive motor is transmitted through a reduction gear.