Multi-stage continuous pyrolysis reactor using molten salt

Abstract

Disclosed is a multi-stage continuous pyrolysis reactor using molten salt, and more specifically to a multi-stage continuous pyrolysis reactor that thermally decomposes polymer waste, such as waste plastics, under anaerobic or oxygen-deficient conditions. The multi-stage continuous pyrolysis reactor using molten salt according to the present invention comprises: a reactor body (100), a multi-stage pyrolysis furnace (200), a drive sprocket (330), a driven sprocket (340), a chain (350), a plurality of transport members (360), and a molten salt circulation unit (400).

What is claimed is: 
     
         1 . A multi-stage continuous pyrolysis reactor using molten salt comprising:
 a reactor body ( 100 ) having an inlet ( 110 ) at one side of the upper part for introducing polymer waste and an outlet ( 120 ) on the lower part for discharging slag consisting of ash and undecomposed char;   a multi-stage pyrolysis furnace ( 200 ) disposed horizontally inside the reactor body ( 100 ), configured to pyrolyze polymer waste as it moves in a zigzag path;   a drive sprocket ( 330 ) coupled to a drive shaft ( 310 ) installed at one end of the molten salt circulation passages opposite the pyrolysis furnace ( 200 );   a driven sprocket ( 340 ) coupled to a driven shaft ( 320 ) installed at the other end of the molten salt circulation passages inside the pyrolysis furnace ( 200 );   a chain ( 350 ) connecting the drive sprocket ( 330 ) and the driven sprocket ( 340 ), moving in an endless loop;   a plurality of transport members ( 360 ) spaced at predetermined intervals along the chain ( 350 ), circulating together with the chain to transport polymer waste;   a molten salt circulation system ( 400 ) connected to the exterior of the reactor body ( 100 ) for circulating molten salt as a liquid-phase heat transfer medium;   wherein the pyrolysis furnace ( 200 ) comprises:   a drying section ( 210 ) located at the uppermost part, configured to remove moisture from the pores of the polymer waste within a temperature range of 80-150° C.;   a melting section ( 220 ) located below the drying section ( 210 ), configured to melt and liquefy the polymer waste within a temperature range of 100-300° C.;   a decomposition section ( 230 ) located below the melting section ( 220 ), configured to vaporize and decompose the molten polymer waste within a temperature range of 200-400° C.; and   a carbonization section ( 240 ) located below the decomposition section ( 230 ), where slag composed of ash and undecomposed char is generated within a temperature range of 300-450° C.;   wherein the pyrolysis furnace ( 200 ) is formed in a rectangular duct shape,   wherein the transport member ( 360 ) is formed in a rectangular plate shape,   wherein it is structured such that, through the continuous circulation of the transport members ( 360 ) together with the chain ( 350 ), the polymer waste is scraped and moved, then dropped to the next stage, and thereafter continues to move while performing pyrolysis,   wherein a series of baffle plates ( 500 ) are arranged in a zigzag pattern along the flow direction of the molten salt within the molten salt circulation passages ( 130 ) of the reactor body ( 100 ); and   wherein the baffle plates ( 500 ) are inclined at a predetermined angle relative to the flow direction of the molten salt, and a through passage ( 510 ) is formed between and at the ends of the baffle plates ( 500 ).   
     
     
         2 . The multi-stage continuous pyrolysis reactor using molten salt according to  claim 1 , wherein the transport members ( 360 ) are in the form of plates and are arranged in a zigzag pattern with one end positioned near the inner wall of the pyrolysis furnace ( 200 ). 
     
     
         3 . The multi-stage continuous pyrolysis reactor using molten salt according to  claim 1 , wherein multiple weight-reducing grooves ( 361 ) are formed on both sides and the center of the transport members ( 360 ) to reduce their weight. 
     
     
         4 . The multi-stage continuous pyrolysis reactor using molten salt according to  claim 1 , wherein the molten salt circulation system ( 400 ) comprises:
 a molten salt tank ( 410 ) for storing the molten salt;   a molten salt boiler ( 420 ) connected to the molten salt tank ( 410 ) for heating the molten salt;   molten salt supply lines ( 430 ) for supplying the high-temperature molten salt heated by the molten salt boiler ( 420 ) to the molten salt circulation passages ( 130 ) of the reactor body ( 100 );   a molten salt discharge line ( 440 ) for returning low-temperature molten salt from the molten salt circulation passages ( 130 ) of the reactor body ( 100 ) back to the molten salt tank ( 410 );   a plurality of valves ( 450 ) installed on the molten salt supply lines ( 430 ) for controlling the fluid flow in each line;   temperature sensors ( 460 ) installed in the pyrolysis furnace ( 200 ) for detecting the temperature of the molten salt; and   a control unit ( 470 ) for adjusting the flow rate of the molten salt through the valves ( 450 ) based on the temperature values measured by the temperature sensors ( 460 ), thereby controlling the temperature of the pyrolysis furnace ( 200 ).   
     
     
         5 . The multi-stage continuous pyrolysis reactor using molten salt according to  claim 1 , wherein the molten salt circulation system ( 400 ) comprises:
 a molten salt tank ( 410 ) for storing the molten salt;   a molten salt boiler ( 420 ) connected to the molten salt tank ( 410 ) for heating the molten salt;   molten salt supply lines ( 430 ) for supplying the high-temperature molten salt heated by the molten salt boiler ( 420 ) to the molten salt circulation passages ( 130 ) of the reactor body ( 100 );   a molten salt discharge line ( 440 ) for returning low-temperature molten salt from the molten salt circulation passages ( 130 ) of the reactor body ( 100 ) back to the molten salt tank ( 410 );   a plurality of valves ( 450 ) installed on the molten salt supply lines ( 430 ) for controlling the fluid flow in each line;   temperature sensors ( 460 ) installed in the pyrolysis furnace ( 200 ) for detecting the temperature of the molten salt;   a control unit ( 470 ) for adjusting the flow rate of the molten salt through the valves ( 450 ) based on the temperature values measured by the temperature sensors ( 460 ), thereby controlling the temperature of the pyrolysis furnace ( 200 );   a preheating heater ( 491 ) installed on one side of the molten salt tank ( 410 ) for preheating the molten salt;   a molten salt return line ( 492 ) for returning the molten salt heated by the molten salt boiler ( 420 ) to the molten salt tank ( 410 ); and   a molten salt drain line ( 493 ) connected between the molten salt tank ( 410 ) and the molten salt supply lines ( 430 ), with a drain valve ( 494 ) installed on one side.