DE1943431U - BELL FURNACE FOR HEAT TREATMENT OF PLATES IN COIL SHAPE OD. DGL. - Google Patents

Description

RA.227GG8-30.if.66

Patent attorneys

Dn ~! Ng. Eichenberg

Dip !, - Ing.Sausdand

DDSSELOORF

Cecllienalteo 76 «Call 432732

SOCIETE AUOHYME HEURTEY, Paris (France), 30-32 rue Guersant,

Bell furnace for the heat treatment of sheet metal in coil form or the like.

Priority: France, May 6, 1965 and August 27, 1965

The heat treatment of sheet metal in coil form under the controlled atmosphere of bell furnaces is carried out in generally slowed down by the long duration of the cooling process for the coils.

It has already been suggested that the filling gas be filled with fans during this cooling process to be taken, to send it through one or more coolers, and to put it back under the protective cover after it has been cooled. Except for the special fans for circulation in the

Each base supporting the coils is still included in the heat exchangers a fan is provided, which sets the filling gas under the cover itself in circulation, especially during the heating season.

The aim of the innovation is, in particular, to simplify apparatuses of this type in that the in each base provided fan is used to circulate part of the filling gas in at least one cooler.

For this purpose, the connections are new

and their position is such that the connection at the entrance of the exchanger lies in a zone of the base in which in the Filling gas, there is an overpressure, while the return opening at the outlet of the exchanger is at one point on the base which the filling gas has a lower pressure.

In a particular embodiment, the

Connection at the inlet of the exchanger combined with a retractable closure member in such a way that ventilation during the Heating process is not disturbed. This closing link lies over a profiled sleeve, which improves the closure, when the closure member is raised. The return opening for the cooled gas is formed by an elongated nozzle which is provided with deflectors.

Since such a base is generally circular, it is convenient to maintain the symmetry of the flows by keeping the connections and the exchangers in pairs diametrically opposite in the corresponding number of Pairs are arranged.

This gives a simplified but effective apparatus which only has a single fan and one

requires a single motor, which can be used for two purposes.

Furthermore, it is according to a further characteristic The innovation is expedient, on the outlet line of the exchanger, which is the return to the base of the furnace causes a shut-off valve to be arranged in the immediate vicinity of this base.

During the warming up of an insert,

which is generally formed by sheet metal coming from a rolling train in the form of a coil, namely produces the mixture of water and soluble oil, which is used for the rolling process and retained on the sheet metal by surface tension becomes, through its evaporation, vapors, which can be deposited at the deepest point of an exchanger, itself if this is switched off by switching off the coolant circulation, and even if the one surrounding the exchanger, the coolant Containing container is emptied.

When starting up the exchanger

for the accelerated cooling of the insert this is condensed Water evaporates again in the exchanger and then in the form of steam through the filling gas during reintroduction the same taken. It can then change the use, e.g. in the case of a ferrous metal, it forms a blue oxide layer, what to avoid.

According to a further characteristic of the innovation, a valve of this type is immediately upstream a pipe socket for the continuous cleaning of the exchanger is provided, which in this counter-current a dose of filling

gas blows into the exchanger during heating of the mission circulates. This circulation is desired by the allows poor tightness of the closure member.

These facilities enable effective Avoidance of the formation of the oxide.

The inflation is explained below with reference to the drawing by way of example.

Pig. 1 is a partial view of a base

a furnace for the heat treatment of sheet metal in coil form with breaking away of parts, which with a single fan and facilities are provided by means of which as required a branched circulation of the filling gas can be established in the exchangers for accelerated cooling.

Pig. 2 shows in the same way a plan view corresponding to the figure.

Fig. 3 shows a side view of the input. connection and the outlet opening of an exchanger,

! Pig. 4 shows, on a larger scale, the sealing of the actuating rod of a closure element for the input connection .

Fig. 5 shows on a larger scale a device for determining the presence of water in an exchanger.

Fig. 6 is a partial view taken from below

Breakaway of parts shows a section of part of the base of a furnace for heat treatment at the location of the cleaning pipe socket and in particular shows its singing opening located between the blades of a diffuser.

7 shows a section in the same way

this base, which is also the location of the cleaning pipe socket and shows the arrangement of the shut-off valve.

As can be seen from FIG. 1, the illustrated Embodiment a base 1 made of a refractory material on, which is attached to a base 2 of metal beams, which in turn is supported by pillars 3. on this refractory base can be placed on a heating bell, not shown, in which by a sand seal 4 the Joint between the base and the lower frustoconical Part | 5 of a protective cover is sealed. A plate 6 carrying the insert is arranged within this cover section 5, on which the actual insert 7 rests, which through

a stack of metal sheets in coil shape is formed, which at

generally / have adjacent turns, but can also have open turns, in any case the coils have an inner channel 8.

The plate 6 rests on the blades 9 of a

Diffuser, which delimits the central section in which the wheel 10 of a centrifugal fan rotates, which is supported by a shaft 11 in a sealed bearing 12. On the outside, this shaft is provided with pulleys 13 for driving by drive belts 14, which in turn are from the output pulleys 15 of an electric motor 16 are driven.

The blades 9 rest on a plate 17 which reinforces the upper part of the refractory base 1.

The enclosure of this plate 17 has a curved upwardly frustoconical section 18, which an annular gap 19 for conveying the filling gas enclosed under the cover 5 can exist, which gas is released from the fan

sucked into the channel 8 and between the blades 9 in the direction is promoted to the annular space 19.

This mode of operation is the usual method of circulating the controlled atmosphere around the use and both during the heating season and during the periods

the temperature
the maintenance / and the cooling.

Between two blades 9 is in the base

1, a lined opening 20 is formed which is connected to a line 21 which is correspondingly cranked is and leads to a pipe coil 22, which is immersed in the water of a cooling container 23, which with nozzle 24 and 25 is provided for supply and discharge of the water. The exit of the pipe coil leads via an ascending pipe 26 directly to another opening 27 of the base and goes beyond this through a flattened nozzle 28, which along the edge 18 and within the enclosure 5 to can be extended to the height of the upper edge of this edge 18.

In the lining of the opening 20 can a

sliding cylindrical closure body 29, which with a window 30 and a flat cap 31 and inside with a Deflector 32 is provided, which is opposite the window 30, which faces the center of the blading. The cylindrical one Body 29 is connected by struts 33 to an actuating rod 34 which passes through the bent knee of the tube 21 in a packing 35 occurs in order to reach the rod 36 a hydraulic working cylinder 37 attached to the corresponding pillar 3.

Likewise, the enlarged neck 28 is in the center with a pair of symmetrical deflectors 38 (Fig. 3) provided to distribute the gas circulation in the space between the periphery of the insert 7 and the inner wall of the protective cover 5.

As can be seen from Fig. 4, the bar occurs

34 by an attached sleeve 39 which has a guide provided with grooves 40 41 has, which generates the pressure drop, which to protect an underlying plastic a stuffing box forming pack 42 of graphitized asbestos is required, which is screwed onto the sleeve by a Plug 43 is compressed through which the rod passes. To achieve additional protection, a connecting piece 44 opens to pressurize between the pack 42 and the guide 41.

For security reasons it is at the deepest

Place of the last turn of the pipe coil 22 an outlet 45 is provided, which through an elastic seal screwed-on plug 46 is closed ", This outlet is connected to a correspondingly curved immersion tube 47, which passes through the opposite wall of the coil and for safety reasons to an alarm bimetallic strip heating burner leads. Other corresponding outlets without an alarm device are at the lowest points of the other turns intended.

The above device preferably has

diametrically opposed pairs of cooling devices, this uniform arrangement following the course of the general Circulation of the filling gas within the cover 5 under the action of the single fan 1o is not impaired.

During the periods of heating of the insert 7, the flat caps 31 are flush against the Plate 17 placed while the closure body 29 in the base have moved in. The circulation of the purging gas is then normal, and the cooling coils 22 are disconnected and inoperative.

During the cooling period, the corresponding closure bodies 29 are closed by the action of the working cylinders 37 raised. The blowing of the fan 10 in conjunction with the arrangement of the lined opening 20 in an overpressure zone and the position of the pipe socket 28 at a point at which a lower Pressure prevails in the general circulation of the filling gas under the lid 5 causes an active circulation of part of the Purging gas in the corresponding exchanger coil 22.

This has an accelerated cooling of the purging gas and thus of the insert 7 without any further effort than that Circulation of water in the containers 23 result.

If water forms in the cooling circuit through condensation, it collects at the lowest point of the Coiled pipe 22 and closes the line 47, the burner goes out. The bimetal strip can then be an alarm contact or close any other safety device.

As can be seen in particular from FIG

the outlet port 26 of an exchanger for cooling in the immediate vicinity Provided near the refractory base 1 with a tightly closing shut-off valve 50. Upstream of this valve a pipe 52 ″ is inserted through a tap 51 into the connection piece 26, which tube supplies a flow of filling gas into the connection piece 26 can. The corresponding cranked tap 51 passes through the refractory base 1 and the plate 17 and ends between the

Blades 9 at a point at which a higher gas pressure can prevail than outside the diffuser 18. This nozzle is always open.

The above device works as follows:

While the insert is heating 7

The fan 10 sucks in the filling gas through the central channel 8 of the insert and conveys it under the cover 5 through the annular gap 19. The closure body 29 is closed, but this closure is not completely tight introduced through the nozzle 52 into the line 26. This gas flow prevents the filler gas from stagnating in the cooler which is not in operation, which could cause the precipitation of the water vapors and the soluble oil contained therein. The valve 50 is closed the exchanger, in spite of the inadequate tightness of the closing body 29, does not work as a condenser in its closed position, since its wall heated in this way cannot serve as a cold source or condensate trap.

During the forced cooling period

of the insert, the valve 50 is open and the closure body 29 is also open. The exchanger is switched on. the Fan 10 supplies filling gas into this exchanger, but this does not encounter any liquid condensation in the exchanger, see above that the circulating filler gas cannot take with it any harmful excess dose of water vapor, thereby oxidizing the insert which would otherwise occur during the accelerated cooling period.

The circulation of the filling gas in the exchanger

during this period of accelerated cooling is in no way caused by the countercurrent of the small amount flowing Cleaning gas disturbed, which continues to escape through the nozzle 52.

The invention can of course be modified

will. Thus, the exchangers can be formed by other parts than the above pipe coils. You can use multiple tubes with single or double flow. They can also have water pipes. These single exchangers can also have a perpendicular position. Instead of being individually connected to two ports, they can also be connected to groups of Inlet and outlet ports connected. A cooling jacket can seal the packing of the actuator rod of the closure body protection. Apparatus for measuring the flow rates and temperatures can be provided on each flow circuit will.

Finally, it should be noted that, although it is advisable to use a high percentage of the total circulating gas to pass into the cooler or coolers, but solid gas withdrawals were a very significant reduction in Result in flow rate during heating.

The above apparatus permits, through use

the then retracted movable connections to avoid obstacles to the circulation during heating.

The above apparatus thus allows for that

Cooler or coolers any percentage of the circulating Discharge filling gas, if necessary. Through the cooler or coolers practically the entirety of the delivery rate of the single centrifugal fan of the base can be directed.

Claims (16)

., ι - .. «. 227668 * 30.4.6g Protection claims 1 «.) Device for cooling the under the Effect of the circulation fan between the base and the protective cover a heating bell furnace for the heat treatment of sheet metal in coil form circulating JP filler gas, characterized by at least a heat exchanger (22), the input of which corresponds to at least one connection (30) which is located under the cover (5) on a Place is at which there is an overpressure, while at least an outlet (28) of the exchanger is also arranged under the cover at a point at which a relative negative pressure prevails in such a way that the circulation in the heat exchanger is produced by the single fan (10), at least the input port (30) includes a body (29) retractable into the base (1). 2.) Device according to claim 1, characterized in that the input connection (30) is combined with a closure member (31) for separating the exchanger (22), wherein the closure member (31) with the retractable body (29) is combined. 3.) Device according to claim 2, characterized in that the closure member (31) is a flow enhancing deflector (32). 4.) Device according to claim 1 to 3, characterized in that the closure member (31) by a Working cylinder (37) is actuated. 5.) Device according to claim 1, characterized that the outlet opening (28) of the heat exchanger (22) forms a flattened pipe socket. 6.) Device according to claim 5, characterized in that that the flattened pipe socket (28) is combined with a symmetrical deflector (38). 7.) Device according to claim 1 to 6, characterized in that the inlet opening (20) between the Blades (9) is located at the outlet of the diffuser of the fan (10), while the exit opening (28) between the frustoconical Edging of the diffuser and the wall (5) of the protective cover is located. 8,) Device according to claim 1 to 7, characterized in that each pair of inlet openings (20) and outlet openings (28) correspond to an exchanger (22), wherein the different pairs are arranged diametrically opposite on the periphery of the base (1) of the furnace. 9 *) Device according to claim 1 to 8, characterized in that the exchanger (22) one in one Has container (23) with water circulation immersed pipe coil. 10,) Device according to claim 9 »characterized in that that the lowest point of the pipe coil (22) has a detector (47) for detecting condensation water. 11.) Device according to claim 1 to 4, characterized in that the actuating rod (34) of the closure body passes through the wall (21) of the inlet pipe of the exchanger (22) in a packing which has a Stuffing box (42), a device (41) for protecting the stuffing box and an intermediate opening (44) for pressurization. 12.) Device according to claim 1, characterized characterized in that on the outlet line (26) of a heat exchanger a tightly closing shut-off valve (50) is arranged for forced cooling. 13 ·) Device according to claim 12, characterized characterized in that the shut-off valve (50) is arranged under the base (1) of the furnace as close as possible to the same. 14.) Device according to claim 12, characterized characterized in that upstream of the shut-off valve (50) a pipe socket (52) is arranged, which is constantly in the exchanger (22) introduces a cleaning flow of filling gas in countercurrent. 15 ·) Device according to claim 14, characterized characterized in that the cleaning flow is taken within the furnace at a point at which there is an overpressure 16.) Device according to claim 15, characterized characterized in that the extraction parts of the cleaning flow lies between the blades (9) of the diffuser.