Vertical heat treatment system

Abstract

A system and method for forming and heat treating metal castings is provided with a vertical heat treatment unit positioned adjacent and downstream from a pouring station at which a series of molds are filled with a molten metal to form the castings. The vertical heat treatment unit includes a vertically oriented furnace chamber in which the castings are received, and which has a reduced footprint to reduce the manufacturing floor space required for the vertical heat treatment unit, and to enable the vertical heat treatment unit to be positioned in close proximity to the pouring station.

1 . A system for forming and heat treating metal castings, the system comprising:
 a pouring station for pouring a molten metal into a mold to form the castings; and   a vertical heat treatment unit positioned downstream from said pouring station;
 wherein said vertical heat treatment unit comprises:
 a furnace oriented in a substantially vertically extending alignment so as to enable a reduction in area occupied by said vertical heat treatment unit, and defining an upstanding a furnace chamber in which the castings are received; and 
 a series of heat sources positioned along said furnace chamber for applying heated fluid flows into said furnace chamber for conveying the castings to said vertical heat treatment unit. 
 
   
   
   
       2 . The system of  claim 1  and further comprising a transport mechanism moveable between said pouring station to said vertical heat treatment unit for conveying the castings to said vertical heat treatment unit. 
   
   
       3 . The system of  claim 1  and wherein said vertical heat treatment unit further comprises a vertically moveable conveyor positioned within said furnace chamber for moving the castings along a vertically extending heat treatment path through said furnace. 
   
   
       4 . The system of  claim 1  and wherein said furnace chamber of said vertical heat treatment unit further comprises a series of compartments arranged in stacked series along said furnace chamber, and in which the castings are loaded for heat treatment, and wherein said heat sources are arranged along floor and ceiling portions of said compartments. 
   
   
       5 . The system of  claim 4  and further comprising a loader mounted within said furnace chamber and adapted to move the castings into and out of said compartments. 
   
   
       6 . The system of  claim 4  and wherein each compartment includes an outer door and wherein said vertical heat treatment unit further comprises an externally mounted loader for loading castings into and removing the castings from each of said compartments. 
   
   
       7 . The system of  claim 1  and further comprising a conveyor extending along a path of travel between said pouring station and said vertical heat treatment unit, and at least one heat source positioned along said path of travel for applying heat to the castings as they are transitioned from said pouring station to said vertical heat treatment unit. 
   
   
       8 . The system of  claim 1  and wherein said heat sources comprise conduction heaters, convection heaters, radiant heaters, infrared heaters, or fuel fired blowers. 
   
   
       9 . The system of  claim 1  and wherein said heat sources comprise a plurality of nozzles arranged about said furnace chamber for applying a heated fluid media to the castings for heat treatment of the castings. 
   
   
       10 . The system of  claim 9  and wherein said nozzles are located approximately 5-7 inches from a centerline of the castings passing through said furnace chamber. 
   
   
       11 . The system of  claim 9  and wherein at least one of said nozzles comprises a slotted nozzle having a slotted opening extending substantially along its length. 
   
   
       12 . The system of  claim 9  and wherein at least one of said nozzles comprises a plenum having series nozzle openings spaced therealong. 
   
   
       13 . A system for forming castings, comprising:
 at least one pouring station in which a molten metal material is introduced into a series of molds;   a plurality of heat treatment cells mounted downstream and in proximity to said at least one pouring station;   wherein said heat treatment cells each comprise a vertically oriented furnace having a reduced footprint to enable said heat treatment cells to be positioned proximate to said at least one pouring station, a plurality of heat sources applying high velocity heated fluid flows to the castings, and a means for retaining the castings within said furnace and in a position to optimize application of the high velocity heated fluid flows to the castings;   a transport system extending along a path adjacent said at least one pouring station and at least one of said heat treatment cells for moving the castings from the pouring station to at least one of said heat treatment cells during which the castings are permitted to solidify.   
   
   
       14 . The system of  claim 13  and wherein said heat sources comprise a series of nozzles applying high velocity fluid flows directed at the castings, wherein said nozzles are positioned at a distance from an approximate center-line of the castings of about 5-7 times a diameter or width of an opening of the nozzles. 
   
   
       15 . The system of  claim 13  and wherein at least one of said nozzles comprises a slotted nozzle having a slotted opening extending substantially along its length. 
   
   
       16 . The system of  claim 13  and wherein at least one of said nozzles comprises a plenum having series nozzle openings spaced therealong. 
   
   
       17 . The system of  claim 13  and wherein said vertical heat treatment unit further comprises a vertically moveable conveyor positioned within said furnace chamber for moving the castings along a vertically extending heat treatment path through said furnace. 
   
   
       18 . The system of  claim 13  and wherein each furnace of each of said heat treatment cells comprises a series of compartments in which at least one casting is received and retained for heat treatment, and wherein said heat sources comprise nozzles arranged along upper and lower portions of said compartments for applying the heated fluid flows to the castings along a desired portions thereof. 
   
   
       19 . The system of  claim 13  and wherein said heat sources comprise nozzles each having ports located a predetermined distance from a centerline of a casting to which said nozzles are applying the heated fluid, based upon a size of said nozzle ports, and applying the heated fluid at a flow velocity of approximately 4,000-40,000 feet per minute. 
   
   
       20 . A method of forming and treating castings, comprising:
 pouring a molten metal into a series of molds to form the castings;   removing and transferring the molds to a cell unit located proximate to the pouring station for heat treatment;   as the molds are transferred to the cell unit, allowing the molten metal to substantially solidify sufficiently to form the castings;   introducing the castings into the cell unit and subjecting the castings to a high temperature, high velocity fluid media flow;   wherein subjecting the castings to a high temperature, high velocity fluid media flow comprises locating a series of nozzles having one or more nozzle openings at a distance from an approximate center-line of the castings being treated by the series of nozzles of approximately 5-7 times the size of the nozzle openings; and   retaining the castings within the cell unit for a time sufficient to heat treat the castings to achieve desired physical properties of the castings.   
   
   
       21 . The method of  claim 20  and wherein subjecting the castings to a high temperature, high velocity fluid media flow further comprises applying a heated air flow from the nozzles at a velocity of approximately 4000-40,000 feet per minute. 
   
   
       22 . The method of  claim 20  and wherein introducing the castings to the cell unit comprises engaging the castings with a loader and loading the castings into selected compartments within the cell unit. 
   
   
       23 . The method of  claim 22  and wherein the nozzles are positioned along at least upper and lower portions of each of the compartments for applying the high temperature, high velocity fluid media flows to the castings as the castings are retained in their compartments. 
   
   
       24 . The method of  claim 22  and wherein the nozzles are mounted along the periphery of the cell unit, and introduce a high temperature, high velocity, turbulent air flow through a furnace chamber of the cell unit, and further comprising conveying the castings through the furnace chamber along a path of movement timed to minimize heat loss from the castings therein. 
   
   
       25 . The method of  claim 24  and wherein conveying the castings through the furnace chamber comprises loading the castings on a carousel and moving the carousel in a stepped motion in forward and reverse directions to provide a desired separation between incoming castings and castings nearing completion of a heat treatment cycle. 
   
   
       26 . The method of  claim 20  and further comprising maintaining the casting at or above a process control temperature for the metal thereof as the castings are transferred from the pouring station to the cell unit. 
   
   
       27 . The method of  claim 20  and further comprising oscillating the nozzles and/or the castings as the high temperature, high velocity fluid media flow is applied to the castings from the nozzles.