Solid material comminution or disintegration – Apparatus – Including means applying fluid to material
Patent
1983-06-21
1985-10-15
Goldberg, Howard N.
Solid material comminution or disintegration
Apparatus
Including means applying fluid to material
241 48, 241 52, 241 80, 241 97, 241152R, B02C 1906, B02C 2312
Patent
active
045469261
DESCRIPTION:
BRIEF SUMMARY
FIELD AND SUMMARY OF THE INVENTION
The present invention is concerned with a pressure-chamber grinder in which the material to be ground, such as talc, bolus, titanium oxide, or soot, is ground to ultra-fine-grain particles by means of grinding gas. The grinding comprises a grinder chamber of substantially circular section, and the chamber is provided with a feed opening for the material to be ground, fed as a gas-tight plug, as well as with tangentially directed nozzles for the grinding gas, fitted as uniformly spaced on the mantle face or at least on a part of same. At the opposite end of the grinder, there is an outlet opening for the ground material, a classifier being connected to the said opening, from which classifier the coarse fraction can be returned into the grinder. As the grinding gas, compressed air or water vapour, is used, favourably superheated water vapour.
In an attempt to improve the energy economy of jet grinders, the first operation has been to replace the ejector feeder of a conventional grinder by a so-called plug feeder, whereby energy economies of up to 10 to 15 percent have been achieved.
In practice, it has, however, been noticed that a grinder constructed in view of the ejector feeder does not operate fully satisfactorily when a plug feeder is used. This is why, for example, a jet grinder has been developed whose grinder chamber has the shape of an oblong box, through which the material to be ground passes, the grinding-gas nozzles being arranged along two opposite walls of the grinder chamber and directed so that the grinding-gas jet coming from each nozzle acts upon the material to be ground in a way for both grinding and changing the direction of flow. The efficiency of the apparatus is relatively good, because the material is subjected to the grinding effect at each nozzle. However, there is the drawback that part of the material to be ground can flow past the nozzle without being at all subjected to the grinding effect.
The object of the present invention is also to eliminate this drawback by developing an apparatus in which the entire material flow is forced to pass through several grinding zones without being able to by-pass them. The pressure-chamber grinder in accordance with the invention is characterized in that the grinder chamber is, by means of a partition wall, divided into a pre-grinding chamber and a grinding chamber proper, the chambers being interconnected by means of at least two Laval nozzles passing through the partition wall and, in a way in itself known, forming an angle with each other, so that the material-gas jets rushing through the nozzles at a supersonic speed collide against each other in the grinding zone formed at the outlet side of the Laval nozzles and that the coarse fraction coming from the classifier is arranged for coming back straight into this grinding zone.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described below in more detail with reference to the attached drawing, wherein
FIG. 1 shows an example of an apparatus in accordance with the invention as a side view, and
FIG. 2 shows a section along line A--A in FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The pressure-chamber grinder in accordance with the present invention comprises a grinder chamber 1 of substantially circular section, which is provided with a feed opening 3 for the material to be ground, fed as a gas-tight plug, and whose opposite end is provided with an outlet opening 5 for the material which has been ground. Tangentially directed grinding-gas nozzles 7 are arranged to be uniformly spaced around the entire circumference of the mantle face over at least a part of the mantle face 6 of the grinder chamber 1. The oblong grinder chamber 1 is, divided into a main pre-grinding chamber 9 and a grinding chamber 10 proper by a substantially transverse partition wall 8. These chambers are interconnected by means of at least two Laval (or laval) nozzles 11 forming an angle with each other. The material-gas jets rushing through the nozzles at a supersonic sp
REFERENCES:
patent: 2846151 (1958-08-01), Wehn et al.
patent: 3186648 (1965-06-01), Mandle et al.
patent: 3643875 (1972-02-01), Dille et al.
patent: 3675858 (1972-07-01), Stephanoff
patent: 4056233 (1977-11-01), Fay
patent: 4304360 (1981-12-01), Luhr et al.
Eley Timothy V.
Goldberg Howard N.
LandOfFree
Pressure-chamber grinder does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Pressure-chamber grinder, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Pressure-chamber grinder will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2431152