Metal founding – With coating means – Associated with a continuous or semicontinuous casting means
Patent
1993-01-11
1994-05-17
Lin, Kuang Y.
Metal founding
With coating means
Associated with a continuous or semicontinuous casting means
164422, 222318, B22D 1110
Patent
active
053119215
DESCRIPTION:
BRIEF SUMMARY
The invention relates to a device of the type corresponding to the precharacterizing clause of claim 1.
The preferred field of application of the invention is the addition of continuous-casting flux powder onto the bath surface of a continuous-casting mold. These continuous-casting flux powders form a layer several centimeters thick on the bath surface. They fuse in their region in contact with the bath surface and form a slag, which is deposited between the mold wall and the solidifying billet. The upper portion of the flux powder layer, which is still loose, acts as thermal insulation and prevents too great a heat loss from the upper billet end.
Entrainment of the molten flux powder slag results in a continuous consumption of flux powder. This consumption is in the region of approx-imately 0.3 kg to 0.8 kg per tonne of steel. This quantity must thus be continuously resupplied, the maintenance of a uniform layer thickness being essential for the quality of the billet surface. Uniformity must be sought both in a vertical as well as in a horizontal direction. Uniformity in the vertical direction means maintaining a certain layer thickness during the entire duration of casting in order continuously to ensure the availability of a sufficient quantity of slag. Uniformity in the horizontal direction means the uniformity of this layer thickness over the billet cross section, in order to obtain a uniform insulating effect at each point.
The starting point of the development was the manual addition of the continuous-casting flux powder. The uniformity of this is not always ensured. This method also requires the presence and continuous attention of an operating person over the entire casting sequence lasting several hours.
It was attempted early on to automate the addition of casting auxiliaries during continuous casting. Two different procedures are known for this, namely devices operating in a pneumatic-mechanical manner or a purely mechanical manner using conveyors, on the one hand, and, on the other hand, devices which operate utilizing gravity.
In a known device of the first ground, a flat conveying channel disposed at the lower end of a supply tank extends from the side to above the continuous-casting mold. Below the supply tank is disposed a gas distribution chamber into which air can be blown, which fluidizes the flux powder situated in the channel and makes it transportable. When air is blown in, there is thus a conveying effect from the supply tank through the channel to the bath surface in the continuous-casting mold. When the air is shut off, the conveying also stops. The control is carried out via temperature-measuring sensors, which are disposed above the mold. If the flux powder layer on the bath surface becomes thinner and the insulating effect of the powder decreases, the temperature increases and the addition of the powder is initiated. This thus takes place not continuously but intermittently, in a similar manner to manual feed. With the automatic powder addition described, an improvement of the billet surface compared with manual powder addition cannot be expected. This has also been confirmed in practice. Pneumatic-mechanical metering devices have not proven themselves and they have not been accepted in practice.
The devices operating purely according to the principle of gravity were first conceived also for the use of pulverulent casting auxiliary. An inclined feed tube leads from a supply tank to above the bath surface. The quantity dispensed forms a conical pile on the bath surface which rises up to the lower end of the feed tube. No more powder then pours down. Only when the conical pile moves away again from the lower end of the tube by consumption does new powder trickle down. This type of automatic control is also called the "chicken feeding" principle because it is widespread in automatic feeding equipment. It has been found, however, that pulverulent casting auxiliaries cannot be reliably applied using this method, since, even with feed tubes disposed at a steep angle (angle >30.deg
Intocast GmbH Feuerfestprodukte und Giesshilfsmittel
Lin Kuang Y.
LandOfFree
Device for the continuous addition of casting auxiliaries onto t does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Device for the continuous addition of casting auxiliaries onto t, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Device for the continuous addition of casting auxiliaries onto t will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-870490