Heat recovery on steel slag

Abstract

An industrial installation for recovering waste radiative heat from steel slag includes: a pit in which molten steel slag is discharged and from which solidified steel slag is removed, using a slag conveying machine or vehicle; an evaporating device for producing hot water and steam and auxiliary equipment, the evaporating device including a heat exchanger having tube-cooled walls; a steel structure supporting the evaporating device; and a lifting system including jacks, such that the heat exchanger is movable vertically from an upper standby position to a lower working position and vice versa. The tube-cooled walls are made of a metal, allowing the heat exchanger to work in an environment presenting sharp temperature gradients and corrosion.

1 . An industrial installation for recovering waste radiative heat from steel slag, the industrial installation comprising-:
 a pit in which molten steel slag is discharged and from which solidified steel slag is removed, using a slag conveying machine or vehicle;   an evaporating device configured to produce hot water and steam and auxiliary equipment, the evaporating device comprising a heat exchanger comprising tube-cooled walls;   a steel structure supporting the evaporating device; and   a lifting system comprising jacks, such that the heat exchanger is movable vertically from an upper standby position to a lower working position and vice versa,   wherein the tube-cooled walls comprise a metal, allowing the heat exchanger to work in an environment presenting sharp temperature gradients and corrosion.   
     
     
         2 . The industrial installation of  claim 1 , wherein the metal of the tube-cooled walls comprises at least one of duplex stainless steels, Monel® alloys, Incoloy® alloys, and/or Inconel® alloys. 
     
     
         3 . The industrial installation of  claim 2 , wherein the metal of the tube-cooled walls comprises at least one of duplex stainless steel SA 789 S31803, superalloys Incoloy® S31277, N08028, N08367, N08825 and Inconel® N06696, N06625, N06617, N 06230, N 06022, and/or N 10276. 
     
     
         4 . The industrial installation of  claim 1 , wherein the steel structure comprises columns or pillars anchored in the ground, the columns or pillars being protected from heat by a concrete shield layer. 
     
     
         5 . The industrial installation of  claim 1 , wherein the heat exchanger is connected to a fixed part of the evaporating device by a plurality of flexible hoses, the fixed part comprising a steam drum and pumps, the plurality of flexible hoses being connected close to an inlet and an outlet of the evaporating device. 
     
     
         6 . The industrial installation of  claim 1 , wherein the heat exchanger is arranged with top panel and side panels only, comprising a cap or an upside down basket, inlet and outlet pipes of the heat exchanger being connected to a top of the cap or upside down basket. 
     
     
         7 . A method for recovering waste radiative heat from steel slag using the industrial installation of  claim 1 , the method comprising:
 operating the lifting system to adapt a distance between a bottom of the heat exchanger and the ground so as to allow a slag conveying machine to have access to the pit area, once the bottom of the heat exchanger is in the upper standby position, either for discharging molten slag into the pit or removing solidified slag from the pit, without any perturbation of recovering waste radiative heat from steel slag or collision risk with the steel structure.