DE102006039611A1 - Device for melting a material and for transferring the melt into a mold or into a distributing device, comprises a crucible for melting the material, a mammoth pump for sucking the melt, and a radiation heater attached over a casting spout - Google Patents

Abstract

The device for melting a material and for transferring the melt into a mold or into a distributing device, comprises a crucible (1) for melting the material, a mammoth pump (6) for sucking the melt from the crucible, and a radiation heater attached over a casting spout (9). The pump comprises an uptake pipe (7) and a gas supply pipe (8). The gas supply pipe passes through the uptake pipe, at which the casting spout with a discharge joins an overflow chamber (14). The casting spout is tiltable around a transverse axis. The crucible has two fusion chambers connected by a connecting tube. The device for melting a material and for transferring the melt into a mold or into a distributing device, comprises a crucible (1) for melting the material, a mammoth pump (6) for sucking the melt from the crucible, and a radiation heater attached over a casting spout (9). The pump comprises an uptake pipe (7) and a gas supply pipe (8). The gas supply pipe passes through the uptake pipe, at which the casting spout with a discharge joins to an overflow chamber (14). The casting spout is tiltable around a transverse axis. The crucible has two fusion chambers connected by a connecting tube. A casting end turned to the uptake pipe of the casting spout, protrudes in the crucible or in an intermediate chamber connected with the crucible. The mold is arranged directly in the overflow chamber. The casting end of the casting spout is formed over the mold. The overflow chamber has bottom drainage or a lateral overflow. Vacuum pumps (5, 11) are assigned to the crucible and the casting spout. The second vacuum pump for the casting spout is adjusted so that the pressure over the casting spout is larger than the pressure over the melt in the crucible. The overflow chamber is provided with a third vacuum pump. The pressure is adjusted in the overflow chamber in such a way that it corresponds to the pressure over the melt. The fusion chamber is provided with a charging device and the other chamber has the mammoth pump. The crucible has a conically running bottom and the uptake tube in the lowest part of the bottom. The overflow chamber is flow-connected with the crucible and a filter, which is arranged in the flow connection.

Description

The The invention relates to a device for melting a Materials and to transfer the melt in a mold or in a distribution device, the device comprising a crucible for melting the material and a pump for sucking the melt from the crucible.

such Devices are known. The crucible will melt with the Stocked material, that afterwards is melted down. Thereafter, the melt z. B. in a mold or poured a distributor trough, including the crucible about a transverse axis is tilted so that the melt over a pout at the edge of the pot flow away can.

• (1) Es ist kein kontinuierlicher Prozess möglich. Zumindest zum Abgießen der Schmelze muss das Einschmelzen unterbrochen werden.
• (2) Schlacke, die sich auf dem Schmelzenspiegel gebildet hat, muss vor dem Abgießen entfernt oder beim Abgießen zurückgehalten werden.
• (3) Bei großen Tiegeln ist der bauliche Aufwand zur Realisierung der Kippbewegung beträchtlich.

This procedure has several disadvantages:

• (1) No continuous process is possible. At least for pouring the melt melting must be interrupted.
• (2) Slag that has formed on the melt level must be removed before casting or retained during casting.
• (3) For large crucibles, the structural complexity for realizing the tilting movement is considerable.

For the reasons mentioned in the EP 0 626 892 B1 proposed a pump in gas piston-piston design for pumping the melt from the crucible. A pump chamber of the pump has an inlet and outlet valve. In addition, a pressure and a vacuum tank is provided. When the inlet valve is open, the pump chamber is connected to the suction tank, so that the melt is sucked through the inlet valve into the pump chamber. Subsequently, the pump chamber is connected to the pressure tank, so that the melt is forced out of the pump chamber via the now open outlet valve for further processing. This process is repeated continuously. However, such pumps could not prevail so far, since they are prone to failure due to their design. In particular, the valves are easily damaged by the hot melt. In the narrow valve cross-sections, it can also easily lead to freezing of the melt when the melt cools locally and thus becomes viscous.

The Invention is thus based on the problem, a device for melting of a material and to transfer the melt in a mold or in a distribution device to that works continuously and with little disruption.

to solution of the problem the invention a device according to the preamble of the claim 1 before with the other features that the pump is a riser and a gas supply pipe exhibiting mammoth pump is.

A Mammoth pump is based on the system of communicating tubes. So long the specific gravity in both tubes is the same, is also the liquid level the same height. dilute but the liquid in the one tube z. B with a gas, the specific gravity decreases the liquid / gas mixture in this tube, so that the mirror rises there accordingly. This system can be used to draw liquid from a basin a higher one to pump located pool. For this, the two basins are going through connected to a riser, in the lower end of a gas admitted becomes.

In Connection with a hot one Melt this has the advantage that a mammoth pump no moving Parts, such as butterfly valves or pistons, which could be damaged if heated too much. Preferably consists of the riser and the gas supply pipe from one with the Melt compatible Material, eg. B. of a ceramic or a quartz glass. Because the pump absolutely simple, can without big ones financial expense easily multiple pumps made of different materials held with the respective melt material harmonize. Through the feeder gas will be added as well the melt is kept liquid, so that freezing is not to be feared.

Around to arrive at a compact design, it is envisaged that the Gas supply pipe through the riser runs. in principle can the gas supply pipe also guided parallel to the riser become. This would have the advantage that the rising in the riser gas not to a Cooling off the Melt in the riser contributes, as it was before when flowing through of the gas supply pipe heated by the melt in the crucible has been.

A Development of the invention provides that to the riser a runner with an outflow to an overflow chamber followed. In the trough can degas the melt again.

In order to prevent the melt from freezing in the pipeline, especially when starting up the system, the channel can be preheated with radiant heating. Further, should the melt cool down in the riser too much, radiant heating can be applied over the gutter to even out the heat loss. Another way to prevent freezing of the melt, especially at low flow rates in the channel, is to provide the channel with a return to the crucible, the melt there to a slightly higher Temperaturni veau to heat, as this is needed for a liquid casting, and return the excess melt back into the crucible. That is, the melt is removed as a product as a product and on the other hand it serves to heat the gutter.

The launder can also be used as a valve. For this, the trough is to a transverse axis mounted tiltably, wherein the riser facing Springs of the trough in the crucible or in an intermediate chamber connected to the crucible protrudes. Thus, if the channel is tilted to the crucible, it flows out Although the mammoth pump exiting melt in the trough, but is returned from there right back into the pot. If by contrast the trough tilted in the opposite direction, the melt flows through the channel to the other end and there z. B. in an overflow chamber.

there a mold may be arranged directly in the overflow chamber, so that the spout facing away from the pouring spout over the mold is located and the melt from the trough directly into the mold flows.

It But it can also be provided that the melt is initially in the overflow chamber flows and there for. B. further degassed. From there it can be via a floor drain or a lateral overflow drain into a mold or the like.

Of the Melting takes place in many cases under vacuum to impurities To prevent the melt or the melt by degassing to clean up of impurities. This vacuum should as possible be maintained in a mold until casting. The invention beats Therefore, before that the crucible and the trough provided with vacuum pumps are, the vacuum pump for the trough is adjusted so that the pressure above the runner is greater than the pressure above the melt in the crucible. The higher one Pressure over the trough arises solely because that pumped into the riser Gas comes out of the melt again.

Also the overflow chamber can be provided with a vacuum pump, the pressure in the overflow chamber is adjusted so that it is the pressure above the melt in the crucible equivalent.

One continuous operation can be particularly well realized when the crucible two melting chambers that has over a communicating connection tube are connected to each other, wherein the one chamber is provided with a charging device and the other has the mammoth pump.

The Mammoth pump can also be used to clean the crucible for cleaning purposes Completely to empty. So that no residues of the melt remain in the crucible, it is envisaged that the crucible will have a tapered bottom to keep the remaining pump sump small, and that the riser ends at the lowest point of the floor. The remaining Residual melt of about one third of the head is using the compressed gas technology emptied through the riser.

The described arrangement can also be used for filtering the melt become. This is the overflow chamber in fluid communication with the crucible, being in the flow connection a filter is arranged. The mammoth pump thus promotes the melt only in the circulation, at the same time a filtration takes place.

in the The following is based on an embodiment the invention closer explained become. To show:

1 a schematic representation of a device according to the invention,

2 a schematic representation of a device according to the invention with a double crucible,

3 the representation of a tiltable trough,

4 a cross section through a trough with a radiant heater,

5 a cross section through a reduced sump volume crucible having a mammoth pump and

6 a crucible with a filtering device for the melt.

It will be initially on the 1 Reference: With 1 is a closed pot called, in which a melt 2 located. The crucible has a heater 3 , a charging facility 4 for supplying material and a first vacuum pump 5 to maintain a vacuum above the melt 2 from Z. B. 10 ^-3 mbar.

To the crucible 1 also includes a mammoth pump 6 coming from a standpipe 7 and a gas supply pipe 8th consists. The riser 7 leads vertically through the crucible lid to the bottom of the crucible 1 , where the lower mouth of the riser 7 just above the ground ends. The gas supply pipe 8th either leads - as shown - through the riser 7 or parallel to the lower mouth of the riser 7 , By means of a pump, not shown, a gas through the Gaszufüh extension tube 8th in the riser 7 blown or pressed, which has the consequence that the melt level in the riser 7 is lifted, so that the melt into a horizontally running trough 9 occurs, in this embodiment, the shape of a cross tube 10 having. In the gutter the gas of the mammoth pump enters 6 from the melt and can be sucked off. The trough 9 is with a second vacuum pump 11 connected above the runner 9 a vacuum of z. B. generated about 10 mbar.

At the other end of the cross tube 10 there is a drain 12 , above the filler neck 13 a heated overflow chamber 14 , which is also executed closed and with a third vacuum pump 15 is provided, the negative pressure of z. B. generated about 10 ^-3 mbar. The overflow chamber 14 is with an overflow 16 provided, under which a mold 17 inside the overflow chamber 14 can be made. But the overflow chamber can also be provided with a floor drain.

The 2 , shows an embodiment in which instead of a crucible 1 two closed jars 1a and 1b are present, which have a connecting pipe 19 communicating with each other. The one crucible 1a is with the charging facility 4 and the other with the mammoth pump 6 Mistake. Both crucibles 1a . 1b are each with a first vacuum pump 5a . 5b Mistake.

According to the 3 is the trough 9 around a transverse axis 18 tiltable in a transition chamber 20 arranged. The mammoth pump 6 facing end protrudes into the crucible 1 The other end has a drain 12 , If, as in the 3 shown, the channel is tilted to the drain, the melt flows from one end to the drain 12 on the other end. If, on the other hand, it is tilted to the other side - which is shown by dot-dash lines - the melt flows back into the crucible. The tiltable trough thus acts as a closing valve.

4 shows those in the transition chamber 20 arranged trough 9 in cross section. Above the trough 9 is located over the entire length of a radiant heater 21 ,

5 shows a pot 1 with a wedge-shaped bottom 22 , where the riser 7 at the lowest point of the soil 22 ends.

According to 6 the device serves to filter the melt. The overflow chamber 14 is inside the crucible 1 and has the shape of a pot 23 with a permeable wall. The from the riser 7 emerging melt enters the pot 23 and flows over it with filters 24 provided walls in the crucible back. The mammoth pump 6 Thus, the melt is merely pumped, thereby passing through the filter 24 passes through and is thereby cleaned.

On the lid of the crucible 1 is the charging facility 4 that with a heater 25 can be provided for preheating and by means of a replacement of the filter 24 can be made.

Instead of a mold are also continuous casting devices, powder plants, etc. conceivable. Also the promotion in an over the crucible arranged chamber, which also for the purpose of enlarging the pumping height can be provided with a second pump is conceivable.

1

crucible

2

melt

 3

heater

 4

charging device

 5

vacuum pump

6

lift pump

 7

riser

 8th

Gas supply pipe

 9

launder

 10

cross tube

11

vacuum pump

 12

outflow

13

filler pipe

14

Overflow chamber

15

vacuum pump

16

overflow

17

mold

 18

transverse axis

19

connecting pipe

 20

Transition chamber

21

radiant heater

 22

ground

 23

pot

 24

filter

 25

heater

Claims (12)

Device for melting a material and transferring the melt into a mold or into a distributor device, the device comprising a crucible ( 1 ) for melting the material and a pump for sucking the melt from the crucible, characterized in that the pump is a riser ( 7 ) and a gas supply pipe ( 8th ) having mammoth pump ( 6 ). Apparatus according to claim 1, characterized in that the gas supply pipe ( 8th ) through the riser ( 7 ) runs. Apparatus according to claim 1 or 2, characterized in that the riser ( 7 ) a runner ( 9 ) with a drain ( 12 ) to an overflow chamber ( 14 ). Device according to one of the preceding claims, characterized in that above the runner ( 9 ) a radiant heater ( 21 ) is attached. Device according to one of the preceding claims, characterized in that the runner ( 9 ) about a transverse axis ( 18 ) is tiltable and that the riser ( 7 ) facing inlets of the trough ( 9 ) in the crucible ( 1 ) or in one with the crucible ( 1 ) connected intermediate chamber protrudes. Device according to one of the preceding claims, characterized in that a mold ( 17 ) directly in the overflow chamber ( 14 ) is arranged and that the riser ( 7 ) facing away from the pouring spout ( 9 ) above the mold ( 17 ) is located. Device according to one of the preceding claims, characterized in that the overflow chamber ( 14 ) a floor drain or a side overflow ( 16 ) having. Device according to one of the preceding claims, characterized in that the crucible ( 1 ) and the trough ( 9 ) Vacuum pumps ( 5 . 11 ), wherein the second vacuum pump ( 11 ) for the runner ( 9 ) is set so that the pressure above the trough ( 9 ) is greater than the pressure above the melt ( 2 ) in the crucible ( 1 ). Apparatus according to claim 8, characterized in that the overflow chamber ( 14 ) with a third vacuum pump ( 15 ), wherein the pressure in the overflow chamber ( 14 ) is adjusted to the pressure above the melt ( 2 ) in the crucible ( 1 ) corresponds. Device according to one of the preceding claims, characterized in that the crucible ( 1 ) two melting chambers ( 1a . 1b ), which via a communicating connecting pipe ( 19 ), wherein the one melting chamber ( 1a ) with a charging device ( 4 ) and the other the mammoth pump ( 6 ) having. Device according to one of the preceding claims, characterized in that the crucible ( 1 ) a tapered bottom ( 22 ) and the riser ( 7 ) at the lowest point of the soil ( 22 ) ends. Apparatus according to claim 1, characterized in that the overflow chamber ( 14 ) with the crucible ( 1 ) is in flow communication and that in the flow connection a filter ( 24 ) is arranged.