US20120024284A1

US20120024284A1 - Device for preheating objects, particularly aluminum strands, rods, or pins, as well as a system having such a device

Info

Publication number: US20120024284A1
Application number: US13/199,189
Authority: US
Inventors: Uwe Guenter; Joachim Sokoll
Original assignee: extrutec GmbH
Current assignee: extrutec GmbH
Priority date: 2009-02-23
Filing date: 2011-08-22
Publication date: 2012-02-02
Also published as: CN102325609A; EP2398603A1; WO2010095032A1

Abstract

In the case of a device (1) for preheating objects (S), particularly aluminum strands, rods, or pins, which device precedes a furnace (2) for the actual heating of the objects (S), and in which device preheating takes place using waste gases of the furnace (2) for actual heating of the objects (S), it is provided that the device has a housing (5) that is configured in the manner of a magazine, to accommodate and preheat multiple objects (S) simultaneously, as a supply, which objects can be passed to the housing (5) by way of a closable inlet opening element (7) and can be removed from it again analogously, preheated, by way of a closable outlet opening element (9), whereby the waste gases of the furnace (2) for actual heating of the objects (S) get into the housing (5) by way of at least one feed channel (3), to preheat the objects. The device (1) is furthermore integrated into a system (A) for processing the objects (S).

Description

CROSS REFERENCE TO RELATED APPLICATIONS

Applicants claim priority under 35 U.S.C. §119 of German Application No. 10 2009 003 527.3 filed Feb. 23, 2009. Applicants also claim priority and this application is a continuation under 35 U.S.C. §120 of International Application No. PCT/IB2010/000357 filed Feb. 23, 2010, which claims priority under 35 U.S.C. §119 of German Application No. 10 2009 003 527.3 filed Feb. 23, 2009. The International Application under PCT article 21(2) was not published in English. The disclosures of the aforesaid International Application and German Application are incorporated herein by reference.

BACKGROUND OF THE INVENTION

The invention relates to a device for preheating objects, particularly aluminum strands, rods, or pins, which device precedes a furnace for the actual heating of the objects, and in which device preheating takes place using waste gases of the furnace for actual heating of the objects.
The invention furthermore relates to a system for processing objects, particularly aluminum strands, rods, or pins, which system comprises at least one device for initial heating or preheating of the objects, a furnace for heating the objects that follows the device for preheating the objects, as well as a processing unit that follows the furnace, as well as at least one unit for transport of the objects in the region of the device for preheating, the furnace, and the processing unit, whereby the initial heating takes place in the device for preheating, using waste gases of the furnace.

STATE OF THE ART

For extrusion of aluminum profiles, it is necessary to heat the profiles, which are configured as aluminum strands, rods, or pins, to a defined process temperature. In order to allow preprocessing, it is generally provided to heat the objects accordingly. Gas-heated furnaces, among other things, are used for heating the objects.
These furnaces serve to heat the object to a specific temperature, so that the object demonstrates a suitable ductility, in order either to be heated further or to be able to already pass the object on to a processing process, for example a process with regard to sawing or shearing.
In the case of materials that consist of aluminum, in particular, it is provided to heat these to a temperature up to 500° C. This is done in gas-operated furnaces, before the actual further processing process, for example pressing, directly follows the last heating process that was carried out.
Combustion gases that contain a certain residual heat occur in the gas-heated furnaces. This residual heat is carried away by way of a waste gas pipe, for example by way of a chimney, whereby the waste gas temperature has a temperature between 200° C. and 500° C.
Devices are already known from the state of the art, with which heating of the objects takes place. In this connection, the objects are passed to a device for preheating by way of a conveyor belt, for example, and thereby pass through a heating zone. In this connection, the dwell time can vary, so that the corresponding preheating temperatures are reached depending on the process velocity.
In this connection, a furnace arrangement for heating slabs to a rolling temperature is known from DE 27 06 345, which arrangement comprises at least two individual furnaces, one of which serves as a pre-furnace for preheating the slabs and is heated using waste gases of the other furnace, which is responsible for actual heating of the slabs. In the case of this furnace arrangement, the individual slabs are continuously transported on roller conveyors. The use of waste gases from a downstream gas furnace for the actual heating of rolled blocks, to preheat rolled blocks made of steel is also described in JP 60 08 2244 A.
Furthermore, a method and a device for heat treatment of objects such as cast strands, ingots, as well as rods, for example made of an aluminum alloy, is known from U.S. Pat. No. 4,373,706. In this connection, a so-called preheating furnace having gas heating, and a so-called holding furnace that follows it are provided, whereby the flames of the gas heating act on the objects directly and at a significantly higher temperature than the holding temperature. The transport devices provided for this purpose work intermittently in the preheating furnace, whereas those in the holding furnace are designed for continuous operation.
Finally, devices for heating metallic objects are known from U.S. Pat. No. 4,289,944 and U.S. Pat. No. 4,619,717, in which devices the transport of the objects takes place, in part, by way of inclined roller conveyors.
A significant disadvantage of these previously known devices for preheating is the circumstance that these devices exclusively work continuously. This means that the objects are transported in the direction of a furnace by way of a feed device, particularly in the configuration of a conveyor belt, and are heated during the continuous transport. In this connection, depending on the dimensions of the aluminum strands, rods, or pins, only a few such objects can be heated at a time.

SUMMARY OF THE INVENTION

It is the task of the invention to propose a device and system for preheating objects such as aluminum strands, rods, or pins, by means of which energy can be saved as compared with the state of the art as indicated.
According to the invention, a device for preheating the corresponding objects is therefore proposed, which device possesses a housing that is configured in the manner of a magazine, to accommodate and preheat multiple objects simultaneously, as a supply, which objects can be passed to the housing by way of a closable inlet opening element and can be removed from it again analogously, preheated, by way of a closable outlet opening element, whereby the waste gases of the furnace for actual heating of the objects that are used for this purpose get into the housing by way of at least one feed channel, to preheat the objects. This is a device for preheating that is configured as a preheating magazine that either directly precedes the heating process or another preheating process, in order to heat the aluminum strands, rods, or pins, which are situated in a magazine or storage unit, from their starting temperature of approximately 4° C. to 20° C. (corresponding to the ambient temperature) to a maximally possible preheating temperature of up to approximately 100° C. Integrating such a device for preheating the said objects into a system for processing these objects also represents a solution according to the invention.

ADVANTAGES OF THE INVENTION

One of the significant advantages of the invention is to preheat a large number of objects to an adequate preheating temperature of up to approximately 100° C., in very simple manner, whereby advantageously, no additional energy is expended for the preheating, but rather, the energy that occurs as waste gas of the furnace provided for the further heating process, in each instance, is used.
Preferably, the device for preheating consists of a housing that has a magazine-like configuration, in which multiple objects can be introduced or removed again after the preheating process, preferably sequentially. Preferably, objects such as those that are configured in rod shape and can be stored parallel to their longitudinal expanse are accommodated.
For this purpose, the device for preheating has closure elements, in each instance, that are configured as inlet and outlet opening elements.
An advantageous further development of the closure elements provides that the inlet and outlet opening elements simultaneously contain elements that make it possible to take the object out of the magazine guide and thus to create the possibility of transferring the object to another device, using a further feed device, for example a manipulator.
Another further development that is advantageously structured provides that the transport of the objects within the device for preheating, which objects lie sequentially one behind the other, for example, is regulated by way of gravity. This is achieved in that the housing of the device is mounted in such a manner that the housing is configured to drop from the inlet opening element to the outlet opening element. This means that when an object is removed from the outlet opening element, the individual objects roll along by one position, so that a new object can be introduced into the inlet opening.
The inlet opening also has elements that make it possible to lay the object onto the closure element, whereby the object gets into the interior of the housing when the closure element is closed.
The device for preheating itself has at least one feed channel that is coupled with the waste gas exit of the furnace, for example a chimney of a system. In this way, it is possible to introduce the waste gas heat, which has a corresponding temperature, into the housing. In this way, the waste gas temperature is used in very simple manner, which is very efficient, to already bring the object to an acceptable temperature in a preheating phase, so that the further energy to be applied is lower.
Other advantageous embodiments are evident from the following description, the drawings, as well as the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

These show:

FIG. 1 a schematic representation of a first exemplary embodiment of a system for processing objects, particularly aluminum strands, rods, or pins;

FIG. 2 an enlarged representation of the preheating system in the configuration of a preheating magazine according to FIG. 1;

FIG. 3 a schematic representation of a second exemplary embodiment of a system for processing objects, particularly aluminum strands, rods, or pins;

FIG. 4 a schematic representation of a third exemplary embodiment of a system for processing objects, particularly aluminum strands, rods, or pins;

FIG. 5 a schematically enlarged representation of the device for preheating according to FIG. 4, in a perspective view;

FIG. 6 a schematically enlarged representation of the device for preheating according to FIG. 4, partly in section;

FIG. 7 a side view of the device for preheating according to FIG. 6.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Different exemplary embodiments are described in FIGS. 1 to 7; they will be explained below.

First Exemplary Embodiment

FIG. 1 shows a first exemplary embodiment of a device 1 for preheating according to the invention, which is disposed directly ahead of a furnace 2 that is needed for heating objects S. The objects S to be heated, such as those shown in FIG. 1 as aluminum rods, are kept on hand in transport and storage devices 4 and are passed to the device 1 for preheating according to the invention by way of a feed device, for example a gripper unit 6 in the configuration of a manipulator. The waste gas heat given off by the furnace 2 gets into a feed channel 3 shown schematically in the drawing, and is passed into the interior of the housing of the device 1 for preheating, which housing is designated as 5. Because of the physical fact that heat rises, the heat gets into the upper region of the device 1 and therefore simultaneously flows around all the aluminum rods S kept on hand in this device.
The device 1 for preheating essentially consists of a housing 5 that is heat-insulated, so that the heat that is supplied and gets into the interior of the housing by way of the feed channel 3 can be utilized as completely as possible within the device 1. In this connection, the device 1 for preheating is structured in such a manner that at least one object S, which is mounted transverse to its longitudinal axis, has flow from a nozzle 12 directed at it within the device 1. Further objects lie directly next to one another or one on top of the other, and are also impacted by the waste gas stream.
The gripper unit 6 now takes an aluminum rod S out of the transport and storage device 4 and passes it to the device 1 for preheating, as shown in FIG. 2.
The device 1 for preheating possesses a closure element in the region of its housing 5, which element is an inlet opening element 7 here, which is configured in the manner of a slide (alternatively so as to pivot), and only opens when an aluminum rod S is being passed in using the gripper unit 6.
Because of a slanted arrangement of the inlet opening element 7, the object S rolls into the housing 5. Subsequently, the inlet opening element 7 is closed and feed of the corresponding waste gas by way of the feed channel 3 takes place directly in the region of the nozzle 12, into the housing 5, so that the waste gas has the possibility of flowing around the aluminum rods S within the housing 5, transverse to the rods, on their top and their bottom, and thus of initially heating all the aluminum rods S uniformly.
At least one pushing cylinder 8 is provided to continue to transport an aluminum rod S that has been introduced in the arrow direction P.
If an aluminum rod S that is situated in the device 1 for preheating is called for, an outlet opening 9 is provided for this purpose, which opens, and the preheated aluminum rod S can be picked up by a feed device 11.
In order to prevent the individual aluminum rods S from moving during an open position, a holding element 10 is provided, which holds the corresponding aluminum rods S within the housing 5 like an engagement element.
Preferably, the feed to the furnace 2 is also encapsulated. For this purpose, an encapsulation element is provided, which completely heat-insulates the path by way of the feed device 11. In this way, cooling of the already preheated aluminum rods S is prevented.

Second Exemplary Embodiment

FIG. 3 shows a second exemplary embodiment of a device 1 for preheating. This device is disposed next to another feed device. This device for preheating 1 again consists of a housing 5, in which multiple objects S are disposed sequentially, parallel to the longitudinal expanse of the objects S, in each instance. Aside from the space for accommodating the objects S, the housing 5 again has closure elements in the configuration of an inlet opening element 7 as well as an outlet opening element 9. In the exemplary embodiment shown here, the inlet opening element 7 and thus the inlet opening is disposed higher than the outlet opening element 9 or the outlet opening, so that a slant in the form of a slanted plane is formed, on which the objects S automatically can move in an arrow direction P, in the direction toward the outlet opening.
The objects S can be transported from the magazine 4 into the region of the inlet opening element 7 of the device for preheating 1 with a gripper unit 6, once again. The inlet opening element 7 used here is configured in such a manner that it can be folded out for receiving the objects, in the manner of a lid, and possesses a receiving element 13. The receiving element 13 is configured in L shape in cross-section, and has not only a receiving arm 13 a but also another holding arm 13 b, which prevents an object S from leaving the outlet opening 7 unintentionally once it has been laid onto the folded-out outlet opening 7. During the closing process, which is preferably activated hydraulically, the inlet opening element 7 folds over in the arrow direction P2 and thereby closes the housing 5 of the device for preheating 1. The object S, in each instance, now lies within the housing 5 of the device for preheating 1. In order to remove an object S that has already been preheated within the housing 5 of the device 1, the outlet opening element 9 is folded out in the arrow direction P3. In this connection, an entrainment element 14 that consists of an entrainment hook 14 a and an entrainment bearing element 14 b is provided within the outlet opening element 9. The entrainment element 14 is preferably disposed over the entire longitudinal expanse of the outlet opening 9, on the inside, which is configured in the manner of a lid. Alternatively, it can also be configured only at certain points.
Preferably as a result of the pivoting movements in the arrow direction P3, the object S lying closest to the outlet opening element 9 is entrained by the entrainment hooks 14 a, and the object S comes to lie against the arm-like configuration of the entrainment bearing element 14 b. From there, this object S can be passed on to the feed device 11, by means of the gripper unit 6.
In order to prevent the objects from automatically rolling forward in the direction of the outlet opening element 9, as a result of the slanted arrangement of the objects within the housing 5, again a holding element 10 is provided, which can preferably be operated pneumatically, hydraulically, or electrically. This prevents the objects S, in each instance, from rolling further in the direction of the outlet opening 9. Only once the object S that lies closest to the outlet opening element 9 has been removed does the holding element 10 open and allow another object S to pass.

Third Exemplary Embodiment

In FIGS. 4 to 7, a third exemplary embodiment of a device 1 for preheating, according to the invention, is shown. The device 1 provided here is integrated into a system A, according to FIG. 4, whereby the system A essentially consists of the storage unit 4 for the objects S as well as the furnace 2 and a gripper unit 6. Furthermore, again a feed device 11 is provided, which passes the heated objects S to the furnace 2.
Here, the device 1 for preheating again consists of a housing 5 in which multiple objects S are disposed sequentially, parallel to the longitudinal expanse of the objects S, in each instance. The housing 5 of this device 1 has not only the space for accommodating the objects S but also, again, an inlet opening element 7 as well as an outlet opening element 9. In the exemplary embodiment shown here, the inlet opening of the inlet opening element 7 is disposed higher than the outlet opening of the outlet opening 9, so that a slant is formed, in which the objects S automatically move in the arrow direction P, in the direction toward the outlet opening.
A gripper unit 6 also provided here transports the object S from the storage device 4 into the region of the inlet opening 7 of the device for preheating 1. The inlet opening 7 is again configured in such a manner that it can be folded out, in the manner of a lid, for receiving an object, and comprises a receiving element 13. The receiving element 13 is configured to be L-shaped in cross-section, and has not only a receiving arm 13 a but an additional holding arm 13 b that prevents the object S from leaving it unintentionally when the object S is laid onto the folded-out inlet opening 7.
During the closing process, which preferably is activated hydraulically, the inlet opening 7 folds in the arrow direction P2 and thereby closes the housing 5 of the device 1. The object S now lies within the housing 5 of the device 1. To remove an object S that has already been preheated within the housing 5, the outlet opening element 9 is folded out in the arrow direction P2. Here again, an entrainment element 14 that consists of an entrainment hook 14 a and of an entrainment leaving element 14 b is provided within the outlet opening element 9. The entrainment element 14 is preferably disposed on the inside, which is configured in the manner of a lid, over the entire longitudinal expanse of the outlet opening element 9. Alternatively, it can also be configured only at certain points.
Preferably, the object S that lies closest to the outlet opening element 9 is entrained by the entrainment hook 14 a by means of the pivoting movements in the arrow direction P2, and the object S comes to lie against the arm-like configuration of the entrainment leaving element 14 b. From there, this object S can be transferred to the feed device 11 by means of the gripper unit 6.
In order to prevent the objects from automatically rolling forward in the direction of the outlet opening element 9, as a result of the slanted arrangement of the objects S within the housing 5, again a holding element 10 is provided, which can preferably be operated pneumatically, hydraulically, or electrically. This holding element 10 prevents the objects S, in each instance, from rolling further in the direction of the outlet opening 9. Only once the object S that lies closest to the outlet opening element 9 has been removed does the holding element 10 open and allow another object S to pass.

Common Features

All of the exemplary embodiments demonstrate the commonality that the preheating of the objects S is operated by means of the waste gas heat generated by the furnace 2 for the actual heating process.
In the case of the third exemplary embodiment, in particular, it is provided to place the device 1 for preheating in the immediate vicinity of the furnace 2. As a result, the waste gases have very short paths and can thus be introduced into the feed channel 3 of the device 1 without overly great losses.
In FIGS. 5 to 7, the device 1 for preheating, according to the invention, according to the third exemplary embodiment, is shown in detail. The device 1 presented here consists of a housing 5 that is suitable for accommodating multiple objects S. The objects S shown here are configured in rod-like manner and are disposed next to one another, parallel to their longitudinal expanse.
The invention makes use of the advantage of having a preheating process precede the actual heating process of the materials to be heated, whereby the waste gases of the actual heating process are predominantly—preferably exclusively—used for preheating itself.
By means of the arrangement of the device for preheating, i.e. its placement ahead of the actual preheating process, energy is saved in very efficient manner, since the materials or objects S are already preheated while being stored in the magazine-like housing 5 and are introduced into the preheating process in this way, so that significantly less energy is therefore required to reach the corresponding temperatures.

REFERENCE SYMBOL LIST

1. preheating device
2. furnace
3. feed channel
4. transport and storage devices
5. housing
6. gripper unit
7. inlet opening element
8. pushing cylinder
9. outlet opening element
10. holding element
11. feed device
12. nozzle
13. receiving arm
13 a bearing arm
13 b holding arm
14 entrainment element
14 a entrainment hook
14 b entrainment bearing element
S aluminum rods—object
P arrow direction
P2 arrow direction
P3 arrow direction
A system

Claims

1. Device (1) for preheating objects (S), particularly aluminum strands, rods, or pins, which device precedes a furnace (2) for the actual heating of the objects (S), and in which device preheating takes place using waste gases of the furnace (2) for actual heating of the objects (S), wherein the device has a housing (5) that is configured in the manner of a magazine, to accommodate and preheat multiple objects (S) simultaneously, as a supply, which objects can be passed to the housing (5) by way of a closable inlet opening element (7) and can be removed from it again analogously, preheated, by way of a closable outlet opening element (9), whereby the waste gases of the furnace (2) for actual heating of the objects (S) get into the housing (5) by way of at least one feed channel (3), to preheat the objects.

2. Device according to claim 1, wherein the housing (5) is configured in the manner of a magazine, in such a manner that the objects (S) are disposed sequentially in it and their transport takes place by means of a pushing cylinder (8).

3. Device according to claim 1, wherein the housing (5) is configured in the manner of a magazine, in such a manner that the objects (S) are disposed sequentially in it, on a slanted plane, in which the inlet opening element (7) is disposed higher relative to the outlet opening element (9), so that transport of the objects (S) takes place by means of gravity.

4. Device according to claim 2, wherein when an inlet opening element (7) and/or outlet opening element (9) is open, at least one grid-like holding element (10) is provided for holding the sequentially disposed objects (S) in place, in each instance.

5. System (A) for processing objects (S), particularly aluminum strands, rods, or pins, which system comprises at least one device (1) for initial heating of the objects (S), a furnace (2) for actually heating the objects that follows this device (1) for initial heating of the objects (S), as well as a processing unit that follows this furnace (2), and at least one transport unit (6) for the objects (S) in the region of the device (1) for preheating, the furnace (2), and the processing unit, in each instance, whereby the initial heating of the objects (S) takes place in the device (1) provided for this purpose, using waste gases of the furnace (2), wherein the device for initial heating (1) is configured according to claim 1.