Patent Application
20210332452
The disclosures made in U.S. Provisional Patent Application No. 63/014,922, filed on Apr. 24, 2020 are specifically incorporated by reference herein as if set forth in their entireties.
The present disclosure is generally related to systems and methods for processing of metallic materials, and in particular, systems and methods for heating metallic articles for annealing, carburizing, etc., of the metallic articles. Other aspects also are described.
Existing retort furnaces generally have inefficient drive systems that require large amounts of torque/power and loading systems which can experience considerable amounts of heat loss during operation. For example, exiting retort furnaces can have side loading mechanisms for loading articles into a retort of the retort furnace and direct drive systems that are directly connected to the retort for driving rotation of the retort. In addition, existing retort furnaces generally rely on substantially continuous full rotation of the retort leading to inefficient processing like annealing or carburizing of the article. Accordingly, it can be seen that a need exists to address the foregoing and other related and unrelated problems or issues in the art.
Briefly described, the present disclosure is directed to a system for processing metallic articles. The metallic articles can include coin blanks, such as blanks for nickels, dimes, quarters, 50 cent pieces, dollars, etc., or other small, metallic articles including, but not limited to, screws, nuts, bolts, washers, etc. The system includes a retort furnace that facilitates annealing, carburizing, etc. of metallic articles. The retort furnace includes a furnace housing or heated box with a furnace chamber or compartment at least partially defined by portions or sections of the furnace housing. The furnace chamber of the retort furnace contains a gas, such as nitrogen, hydrogen, or other gases, or combinations thereof. The retort furnace further has heaters that heat or maintain the furnace chamber of the retort furnace to/at a prescribed temperature.
The system further includes a retort that is rotatably mounted to the furnace housing and that extends within the furnace chamber. The retort is configured to receive metallic articles for annealing, carburizing, or other suitable heat processing of the metallic articles. The retort includes a retort body having a substantially elongated, cylindrical shape or configuration. In one embodiment, the retort body includes a cylindrical, circumferential sidewall at least partially defining a retort chamber or cavity of the retort body into which the metallic articles are received. The retort body further includes a charge inlet and a discharge outlet, each defined in the circumferential sidewall and in communication with the chamber of the retort body for charging and discharging of the metallic articles into/from the chamber of the retort body. In one embodiment, the inlet is formed at or substantially adjacent an upstream or charge end of the retort body, and the outlet is formed at or substantially adjacent a downstream or discharge end of the retort body.
The retort also includes internal helical flights or helical members positioned within the chamber of the retort body and extending along the retort body for moving metallic articles from the upstream end to the downstream end of the retort body. The helical flights can include a flight body, which can include a unitary structure or can be made up of a plurality of interconnected parts or sections, with a helical shape or construction, e.g., similar in shape to a helical screw or auger, that is fixed to the retort body. In this regard, the helical flights are configured to engage and move metallic articles received within the inlet at the upstream end of the retort body towards the outlet at the downstream end of the retort body, with oscillation or rotation of the retort, for carbonizing or annealing of the metallic articles. Other configurations of flights, including non-helical flights, also can be used.
In addition, the system includes a support system movably mounting the retort to the retort furnace. The support system can include a pair of opposing shafts or hollow tubes connected to the retort body. The shafts can include a first, upstream shaft that is connected to and extends from the upstream end of the retort body, and a second, downstream shaft that is connected to and extends from the downstream end of the retort body. The support system further can include bearing assemblies or other suitable mounting assemblies that movably support the shafts. The bearing assemblies can include bearings connected to the shafts, such that the shafts are rotatable with respect to the furnace housing the bearing assembles further can include and beams or supports connecting the bearings to the furnace housing. The shafts can be connected to the retort body at or along a first end portion or area of each shaft and can be connected to the bearings of the bearing assembles at a second, opposing end portion or area of the shafts. The shafts and bearings can be cooled, e.g., by one or more water or air gas cooling systems. In addition, in some embodiments, a gas system can be provided in communication with the shafts, the gas system will supply one or more gases, such as hydrogen, nitrogen, other gases, or combinations thereof, can be introduced into the retort through the shafts at one or both ends of the retort, e.g., via openings, passages, injectors, etc.
The support system also can include a support or mounting assembly connecting the shafts to the upstream and downstream ends of the retort body. In one embodiment, the support assembly can include one or more conical or frusto-conical structures connecting the shafts to the upstream and downstream ends of the retort body. The conical structures can be configured to help to reduce stresses or forces, such as, bending or torsion, experienced along the shafts, e.g., to reduce, inhibit, or prevent wear, damage, breakage, etc., of the shafts.
The system further includes one or more retort drive systems or mechanisms operatively connected to one or both of the opposing shafts to drive movement of the retort. The system also can include a control system with a controller in communication with drive system(s) and operable to transmit one or more control signals to the drive system(s) to control driving, e.g., activating, stopping reversing, etc., of the retort. In particular, the control system can control the drive system to rotate and/or oscillate the retort back and forth during heating of the metallic articles. In one embodiment, the drive system can oscillate the retort up to about 360° back and forth. In addition, or in the alternative, the drive system can oscillate the retort up to about 90° or up to about 180° back and forth. The control system further can be configured to rotate the retort body multiple revolutions at different and variable speeds without departing from the scope of the present disclosure.
The system also includes a discharge assembly that is in communication with the discharge outlet of retort body, and a quenching tank or container that receives metallic articles discharged from the discharge outlet. In one embodiment, the discharge assembly includes a discharge chute that extends from the furnace housing into the quenching tank. The discharge chute can be substantially sealed with the retort body to help to reduce dissipation of heat from the retort furnace.
In addition, the system includes an inlet assembly in communication with the charge inlet of the retort body for loading of metallic articles into the retort body. In one embodiment, the inlet assembly includes a fixed inlet or charging chute positioned along a top portion or section of the furnace body. The fixed inlet chute further can be configured to vertically discharge metallic articles into the chamber of the retort body. The fixed inlet chute can be substantially sealed against the retort body to help to reduce dissipation of heat from the retort furnace.
In one embodiment, the charge inlet includes an inlet slot or elongated aperture defined in the circumferential sidewall of the retort body. This inlet slot can be configured to be periodically brought into communication with the fixed inlet chute during oscillation or rotation of the retort for charging of metallic articles into the chamber of the retort body. In addition, the discharge outlet can include a discharge slot or elongated aperture defined in the circumferential sidewall of the retort body. This discharge slot also can be configured to be periodically brought into communication with the discharge chute extending from the furnace housing during oscillation or rotation of the retort for discharging metallic articles from the chamber of the retort body into the container. Periodic communication between the inlet slot and the fixed inlet chute and between the discharge slot and discharge chute can help to provide a substantially constant flow of metallic articles through the chamber of the retort body.
Furthermore, the retort can include an inlet section or area at or substantially adjacent the upstream end of the retort body. The inlet section or area can be configured to direct or funnel metallic articles received into the retort body through the charge inlet to an interior surface of the circumferential sidewall of the retort body in a cascading manner, such that metallic articles do not free fall from the charge inlet in the retort body to the opposing side of the retort body. In this regard, the inlet section or area can help to reduce, inhibit, or prevent damage to, e.g., scoring, nicking, scratching, etc., metallic articles received into the chamber of the retort body.
In one embodiment, the inlet section can include one or more support bars or engagement members positioned within the chamber of the retort body to engage and direct metallic articles received in the retort body from the inlet slot. In particular, the support bar(s) can be connect to and oscillate or rotate with the retort to cascade metallic articles to interior surface of the circumferential sidewall of the retort as the retort moves to prevent dropping of metallic articles directly into the retort body, i.e., dropping directly from the inlet slot to the opposing interior surface of the circumferential sidewall. The support bar(s) can be in at least partial alignment with the inlet slot to engage and direct metallic articles received into the chamber of the retort body through the inlet slot. The support bar(s) further can be sloped or angled in relation to the inlet slot to help to direct metallic articles to the interior surface of the circumferential sidewall, without jamming or other substantial disruptions of the flow of metallic articles through the inlet slot.
In alternative embodiments, the inlet section or area of the retort can include a plurality of support bars or engagement members configured to engage and direct metallic articles received into the retort body through the charge inlet in a cascading manner to help to reduce, prevent, or inhibit damage to the metallic articles as the metallic articles are received into the retort body. In this regard, the plurality of engagement members can define a path or passage through which the metallic articles move/are directed as the retort body is oscillated or rotated.
The system further can be configured to run a cleaning cycle for removal of lodged or stuck metallic articles or debris from the chamber of the retort body. During the cleaning cycle, cleaning materials, including but not limited to hard spherical cleaning objects, can be received in the retort body, e.g., through the inlet slot, and the retort can be rotated or oscillated for a predetermined time interval. The cleaning materials can be moved and directed by the helical flights from the upstream end of the retort body to the downstream end of the retort body and can engage lodged metallic articles or debris to clean the chamber of the retort body. The cleaning materials can be discharged from the discharge slot of the retort body.
Additionally, the present disclosure provides a method for processing metallic articles. According to the method, metallic articles can be loaded or otherwise received within an inlet chute of a retort furnace. One or more heaters can be activated (e.g., via control system) to heat a furnace chamber of the retort furnace to a prescribed temperature, e.g., between about 1000° F. and about 2000° F., such as 1600° F., and up to 2100° F. or more, for carburizing or annealing of metallic articles. A retort of the retort furnace can be oscillated back and forth, e.g., in opposite first and second directions of up to about 90 degrees, up to about 180 degrees, up to about 360 degrees, etc. in either or both directions, and each time the inlet chute is at least partially aligned with a charge inlet defined through a circumferential surface of the retort, with oscillation of the retort, metallic articles can be received from the inlet chute into a chamber of the retort. The metallic articles can be received into an inlet section of the retort including one or more support bars that engage and direct metallic articles in the chamber of the retort, e.g., in a cascading manner to an interior surface of the retort.
Furthermore, metallic articles received within the retort can be engaged by an internal helical flights positioned in the chamber of the retort (e.g., upon exiting of the inlet section) and moved toward a discharge end of the retort. In particular, due to oscillation of the retort, metallic articles can be engaged by various sections of the internal helical flights and moved along the retort to the discharge end of the retort. The oscillating motion and/or back and forth rotation of the retort will be controlled to control a dwell time of the metallic articles within the retort chamber to facilitate a substantially uniform heating thereof. Thus, the retort can have a reduced or more compact size and/or, configuration while enabling a desired treatment (e.g. annealing carburizing or other heat treatment).
When metallic articles reach the discharge end of the retort, metallic articles can be discharged from the retort through a discharge outlet defined through a circumferential surface of the retort. For example, metallic articles can be discharged from the discharge outlet each time the discharge outlet is at least partially aligned with a discharge chute, due to oscillation or rotation of the retort.
The metallic articles can be directed through the discharge chute to one or more quenching tanks. After quenching of metallic articles, metallic articles can be moved from the quenching tank to one or more additional processing stations for additional or post processing of annealed, carburized, etc. metallic articles, e.g., for cutting, stamping, etc. of metallic articles.
The method further can include cleaning cycle for the retort. For example, one or more cleaning materials, e.g., including spherical objects, can be added to the retort chamber and the retort can be oscillated or rotated, such that the cleaning materials move through the retort to dislodge any metallic articles or debris lodged or stuck in the chamber of the retort.
These and other advantages and aspects of the embodiments of the disclosure will become apparent and more readily appreciated from the following detailed description of the embodiments and the claims, taken in conjunction with the accompanying drawings. Moreover, it is to be understood that both the foregoing summary of the disclosure and the following detailed description are exemplary and intended to provide further explanation without limiting the scope of the disclosure as claimed.
The accompanying drawings, which are included to provide a further understanding of the embodiments of the present disclosure, are incorporated in and constitute a part of this specification, illustrate embodiments of the invention, and together with the detailed description, serve to explain the principles of the embodiments discussed herein. No attempt is made to show structural details of this disclosure in more detail than may be necessary for a fundamental understanding of the exemplary embodiments discussed herein and the various ways in which they may be practiced.
The following description is provided as an enabling teaching of embodiments of this disclosure. Those skilled in the relevant art will recognize that many changes can be made to the embodiments described, while still obtaining the beneficial results. It will also be apparent that some of the desired benefits of the embodiments described can be obtained by selecting some of the features of the embodiments without utilizing other features. Accordingly, those who work in the art will recognize that many modifications and adaptations to the embodiments described are possible and may even be desirable in certain circumstances. Thus, the following description is provided as illustrative of the principles of the embodiments of the present disclosure and not in limitation thereof.
As shown in
In addition, the system 10 can include one or more additional or post processing stations 16 for additional or subsequent processing of annealed, carburized, etc. metallic articles. The post processing stations 16 can include stamping stations, cutting stations, etc., or other suitable additional or post processing stations for metallic articles as will be understood by those skilled in the art.
As
As additionally shown in
According to embodiments of the present disclosure, the helical flights 42 each include a flight body 44 with a helical shape, similar to a helical screw or auger, that is fixed to the circumferential sidewall 34 of the retort body 32. Other configurations also can be used. In the illustrated embodiment, as generally shown in
As the retort 30 is oscillated or rotated, a metallic article can be engaged by various sections or areas 44A of the flight body 44 to direct and move the metallic article toward the discharge 40 of the retort body 32. In some embodiments, a metallic article may travel from the upstream end 32A to the downstream end 32B of the retort body 32 in a range between about 30 minutes to about 60 minutes or longer or less depending on the process required and size/weight of the article. The flight body 44 further can define openings or passages 46 through the center of each of the helical flights 42, and in some instances, metallic articles can spill or topple over the flight body 44 between different sections or areas 44A of the flight body 44 toward the discharge 40, though the quantity of metallic articles loaded into the retort 30 can be selected to reduce, inhibit, or prevent spill-over of metallic articles. In some embodiments, the flight body 44 or each helical flight has a thickness in a range of about 0.5 inches to about 0.75 inches, such as 0.6 inches; a width of in a range of about 8 inches to about 12 inches, such as about 9 inches; and a pitch length in a range of about 10 inches to about 14 inches, such as about 12 inches.
In some embodiments, the shafts 52, 54 can have a diameter in a range of about 12 inches to about 24 inches, such as about 16 inches to 20 inches; can extend from the retort body 32 a distance in a range from about 28 inches to about 45 inches, such as about 30 inches to about 42 inches; and can extend into the retort body 32 a distance in a range from about 12 inches to about 18 inches. The reduced diameter of the shafts 52 and 54 in comparison to the retort body 32 can help to reduce power and/or torque requirements, as well increase efficiency, for driving of the retort 30 in comparison to traditional retort furnaces that have direct drive mechanism, (e.g., that is directly connected to the body of the retort). The reduced size of the shafts also can help to reduce heat transfer or heat loss from the retort furnace 12, and also reduces the temperature, as well as thermal expansion, of the shafts (and the retort drive system) further increasing the efficiency of the retort furnace 12 in comparison to traditional retort furnaces (e.g., which may have support/drive systems requiring direct driving of the retort). The configuration of the shafts also can allow for improved sealing of the furnace (e.g., reducing circumferential sealing requirements), and less leakage of furnace atmosphere in comparison to traditional retort furnaces.
In some embodiments, the system 10 further can include a gas or atmospheric system configured to supply one or more gases, such as hydrogen, nitrogen, other gases, or combinations thereof, to the chamber 36 of the retort body 32. The gas system can be configured to provide one or more gases to the chamber of the retort body 32 through or along one or both of the shafts 52 and/or 54. In this regard, the shafts 52 and/or 54 can include passages, openings, etc., defined along, in, or through the shafts 52/54 for providing one or more gases to the chamber 26 of the retort body 32. The gas system further can include tubing, hoses, pumps, injectors, etc., e.g., in communication with the passages, openings, etc., of the shafts, and configured to facilitate delivery of the one or more gases to the chamber 26 of the retort body 32.
As also illustrated in
In addition, as generally shown in
The system 10 further includes one or more retort drive systems or mechanisms operatively connected to one or both of the opposing shafts 52/54 to drive movement of the retort 30. The system 10 also can include one or more control systems including at least one controller, CPU, processor, etc. in communication with retort drive system(s) and operable to transmit one or more control signals to the retort driving system(s) to control driving, e.g., activating, varying the speed, stopping reversing, etc., of the drive system.
According to embodiments of the present disclosure, the control system can control the drive system to oscillate the retort back and forth during heating of the metallic articles e.g., in opposite, first and second directions or in a side to side motion. In one embodiment, the drive system can oscillate the retort 30 up to about 360° back and forth. In another embodiment, the drive system can oscillate the retort 30 up to about 180° back and forth, and in yet another embodiment, the drive system can continuously oscillate the retort 30 up to about 90° back and forth. The drive system can be controlled to drive the retort at substantially constant speeds or at varying speeds. In some embodiments, the drive system can oscillate the retort at varying amounts, e.g., combinations or cycles of oscillations of up to 360°, up to 180°, up to, 90° in one or more directions. Oscillating of the retort can improve the processing (to achieve better temperature uniformity and longer dwell times with a shorter retort) of metallic articles in comparison to continuous full rotation of the retort; however, the control system further can be configured to rotate the retort body multiple revolutions without departing from the scope of the present disclosure.
In one embodiment, the discharge outlet 40 can include a plurality of discharge slots or elongated openings 84 defined through the circumferential sidewall 34 of the retort body 32, though a single discharge slot or opening can be employed without departing from the scope of the present disclosure. As the discharge slots 84 are periodically brought into at least partial alignment with the discharge chute 82 (e.g., an inlet or opening of the discharge chute), metallic articles pass through the aligned discharge slot 84 and into the discharge chute 84 to be directed to the quenching tank 14. Furthermore, the discharge chute 82 can be substantially sealed against the outer circumferential surface 34B of the retort body 32, e.g., via a sealing material or sealing members, to help to reduce dissipation of heat from the retort furnace 12 during operation.
In addition, as shown in
In one embodiment, as shown in
Furthermore, the fixed inlet chute 92 can be substantially sealed against the outer circumferential surface 34B of the retort body 32, e.g., by a sealing material or one or more sealing members, to help to reduce dissipation of heat from the retort furnace 12. The fixed inlet chute 92 also allows for preheating of the metallic articles in the inlet chute, e.g., due to exhaust 96 from the retort body when the inlet chute 92 and inlet slot 94 are at least partially aligned. In some embodiments, a refractory ring 98 optionally can be included to set up a preheat chamber.
In one embodiment, the inlet section 100 can include one or more support bars or engagement members 102 positioned within the chamber 36 of the retort body 32 to engage and direct metallic articles receive in the retort body 32 from the inlet slot 94. In particular, the support bar(s) 102 can be connect to and oscillate or rotate with the retort body 32 to cascade the metallic articles toward a circumferential side portion of the interior surface 34A of the circumferential sidewall 34 of the retort 30 as the retort 30 moves to prevent dropping of metallic articles directly into the retort 30, i.e., dropping directly from the inlet slot 94 and straight down onto the opposing interior surface 34A of the circumferential sidewall 34. The support bar(s) 102 can be in at least partial alignment with the inlet slot 94 to engage metallic articles received into the chamber 36 of the retort body 32 through the inlet slot 94. The support bar(s) 102 further can be sloped or angled in relation to the inlet slot 94 to help to direct metallic articles to the interior surface 34A of the circumferential sidewall 34, without jamming or other substantial disruptions of the flow of metallic articles through the inlet slot 94.
As shown in
In alternative embodiments, as shown in
According to one embodiment of the present disclosure, the system 10 further can be configured to run a cleaning cycle for removal of lodged or stuck metallic articles or debris from the chamber 36 of the retort body 32. During the cleaning cycle, cleaning materials, including but not limited to hard spherical cleaning objects, can be received in the retort body 32, e.g., through the inlet slot 94, and the retort 30 can be rotated or oscillated for a predetermined time interval. The cleaning materials can be moved and directed by the helical flights 42 from the upstream end 32A of the retort body 32 to the downstream end 32B of the retort body 32 and can engage lodged metallic articles or debris to clean the chamber 36 of the retort body 32. The cleaning materials can be discharged from the discharge slot 84 of the retort body 32.
According to a method or process for processing metallic articles, and during operation of the system 10, metallic articles can be loaded or otherwise received within an inlet chute 92 of a retort furnace 12. One or more heaters can be activated (e.g., via a control system) to heat a furnace chamber 22 of the retort furnace 12 to a prescribed temperature, e.g., to about 1000° F., to about 1600° F., to about 2100° F. or more, for carburizing or annealing or other heat treatment of the metallic articles.
A retort 30 of the retort furnace 12 further can be oscillated back and forth, e.g., up to about 90°, up to about 180°, up to about 360°, etc. back and forth, and periodically the inlet chute 92 is brought into at least partially alignment with a charge inlet slot 94 defined through a circumferential surface 34 of the retort 30, with oscillation of the retort 30, and metallic articles can be received from the inlet chute 92 into a chamber 36 of the retort 30.
The metallic articles can be received into an inlet section 100 of the retort 30 including one or more support bars 102 or 110 that are configured to engage and direct metallic articles into the chamber 36 of the retort 30 in a cascading manner to an interior surface 34A of the retort 30, e.g., to reduce, inhibit, or prevent damage to the metallic articles loaded into the retort 30.
Furthermore, metallic articles received within the retort 30 can be engaged by helical flights 42 positioned in the chamber 36 of the retort 30 (e.g., upon exiting of the inlet section 100) and moved toward a discharge end 32 of the retort 30. In particular, due to oscillation of the retort 30, metallic articles can be engaged by various sections, e.g., 44A, of the helical flights 42 and moved along the retort 30 to the discharge end 32B of the retort 30.
When metallic articles reach the discharge end 32B of the retort 30, metallic articles can be discharged from the retort 30 through a discharge outlet slot 84 defined through the circumferential surface 34 of the retort 30. For example, metallic articles can be discharged periodically from the discharge outlet slot 84 each time the discharge outlet slot 84 is at least partially aligned with a discharge chute 82, during oscillation (or rotation) of the retort 30.
The metallic articles can be directed through the discharge chute 82 to one or more quenching tanks 14 including a liquid or gas for cooling metallic articles. After quenching of metallic articles, metallic articles can be moved from the quenching tank 14 to one or more additional processing stations 16 for additional or post processing of annealed, carburized, etc. metallic articles, e.g., processing stations for cutting, stamping, etc. of metallic articles.
The method further can include a cleaning cycle for the retort. For example, one or more cleaning materials, e.g., spherical object, can be added to the retort chamber 36 and the retort 30 can be oscillated or rotated, e.g., at constant or variable speeds, such that the cleaning materials move through the retort 30 to dislodge any metallic articles or debris lodged or stuck in the chamber 36 of the retort 30.
The foregoing description generally illustrates and describes various embodiments of the present invention. It will, however, be understood by those skilled in the art that various changes and modifications can be made to the above-discussed construction of the present invention without departing from the spirit and scope of the invention as disclosed herein, and that it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as being illustrative, and not to be taken in a limiting sense. Furthermore, the scope of the present disclosure shall be construed to cover various modifications, combinations, additions, alterations, etc., above and to the above-described embodiments, which shall be considered to be within the scope of the present invention. Accordingly, various features and characteristics of the present invention as discussed herein may be selectively interchanged and applied to other illustrated and non-illustrated embodiments of the invention, and numerous variations, modifications, and additions further can be made thereto without departing from the spirit and scope of the present invention as set forth in the appended claims.
The present Patent application claims the benefit of pending U.S. Provisional Patent Application No. 63/014,922, filed on Apr. 24, 2020.
| Number | Date | Country | |
|---|---|---|---|
| 63014922 | Apr 2020 | US |
