Coating processes – With post-treatment of coating or coating material – Coating material recirculation or regeneration
Patent
1990-04-19
1992-04-14
Beck, Shrive
Coating processes
With post-treatment of coating or coating material
Coating material recirculation or regeneration
427426, 427427, 118302, 118304, 118707, 118708, 118681, 264 30, B05B 716, B05D 102, B05D 134, B05C 1100
Patent
active
051046962
DESCRIPTION:
BRIEF SUMMARY
The invention relates to a process for intermittently spraying a setting pasty composition mixed with a tempering liquid, in particular for building up refractory linings of metallurgical vessels, the composition being conveyed from a preparing station at which it is prepared, to a delivery nozzle. Furthermore, the invention relates to a device for carrying out the process.
In a process of the above kind which is used e.g. in the field of building construction for the application of roughcast or when repairing refractory linings, there is always the problem that whenever delivery of the composition is interrupted, it must at least be removed from the conveyor, any reservoir arranged therebefore, the ducts and the delivery nozzle, and said parts must be cleaned by rinsing with water in order to prevent the composition from hardening or thickening, as otherwise the hardened or thickened composition would block the delivery nozzle when spraying is started again. Furthermore, when restarting spraying of the composition there is the problem that more tempering liquid than is actually desirable for processing must mostly be added when remixing the composition. As a result of the above, a strongly diluted slurry of the composition ensues which is not usable and has to be disposed of at some expense and, additionally, there are considerable losses of material.
These problems arise especially when repairing refractory linings of metallurgical vessels, e.g. distributing chutes in continuous casting installations, by applying a refractory composition. As said refractory linings are subject to continuous wear, they must be repaired frequently within short periods. Between these successive spraying repairs, there are interruptions for up to about 3 to 5 hours. Because of the frequent turning off and starting up of the spraying apparatus, the amount of thinly diluted slurry which has to be disposed of and the losses of refractory material are extremely high.
It is the object of the invention to arrange a process of the aforementioned kind in such a manner that the prepared pasty composition remains usable during spraying interruptions which may last for several hours.
This object is achieved according to the invention in that the composition is conveyed during the interruptions in a circuit that includes the delivery nozzle.
This measure prevents the composition from hardening or thickening in the ducts or the delivery nozzle and it ensures furthermore that the spraying of the composition may be taken up at any time, the composition having an applicable consistence. The loss of material is thus considerably reduced, especially when for repairs on the refractory lining of metallurgical vessels the spraying of material has to be interrupted frequently.
According to a further feature of the invention, the circular conveyance of the composition during the interruptions may take place intermittently, preferably the amount of tempering liquid in the pasty composition being slightly increased.
This is especially recommended for compositions with a longer setting period in order to minimize wear of the apparatuses which prepare and deliver the composition. When adding some tempering liquid there is the advantage that a lower pressure may be used and the consistence of the composition still remains usable.
A further object of the invention refers to a device for carrying out the process according to the invention.
With regard to a device comprising a mixer for mixing the dry composition with a tempering liquid and comprising a conveyor placed after the mixer in the conveying direction of the composition and serving to lead the prepared composition to the delivery nozzle, it is hereby proposed that in the conveying direction of the composition an opening is arranged in the conveying path, said opening being located before the inlet of the conveyor, and the delivery nozzle being insertable into said opening.
This measure enables the process according to the invention to be carried out in a simple manner and ensures that the compos
REFERENCES:
patent: 3141793 (1964-07-01), Oliphant
patent: 3413385 (1968-11-01), Komac et al.
patent: 3644138 (1972-02-01), Stiefken
patent: 4127626 (1978-11-01), Kubo
patent: 4708745 (1987-11-01), Schonhausen
Beck Shrive
Burke Margaret
Veitscher Magnesitwerkeactien-Gesellschaft
LandOfFree
Process and device for intermittenly spraying a pasty compositio does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Process and device for intermittenly spraying a pasty compositio, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process and device for intermittenly spraying a pasty compositio will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2348084