FR2523474A1 - High speed rotary mixing mill for e.g. cement and clay flakes - made dust free by rotary valve inlet and screw conveyor discharge - Google Patents

Abstract

A machine for continuously milling and mixing dry or slightly damp powders, e.g. cement with flakes of clay. The machine is of the type comprising a milling and mixing chamber which is gravity fed with materials from a storage hopper via an inlet orifice. The chamber also has a discharge mechanism which delivers the mixt. via an outlet orifice. During the milling and mixing operation there is no open passage between the mixing chamber and the surrounding atmos. via either the inlet or the outlet orifice. The inlet orifice is sealed with a rotary valve between mixing chamber and hopper. The outlet orifice is accessible from the mixing chamber only via a tubular casing contg. a discharge conveyor screw. The milling and mixing mechanism pref. comprises two contra-rotating coaxial cages with overlapped, axially extending bars at different pitch circle dias. Materials require high speed rotation of milling and mixing rotors which tends to spread dust into the atmos. with rotary valve inlet and screw conveyor outlet, the process is dust-free.

Description

The present invention relates to a divider and mixer device for dry or slightly wet pulverulent materials, such as for example clay and cement.

The clay before being divided is in the form of small, compact, slightly damp lamellae.

When the clay is mixed with the cement, the cement dries the clay which facilitates the division of the clay lamellae and makes it possible to obtain an identical particle size of the two materials and therefore their intimate mixture.

If the mixing elements rotate at low speed, the clay lamellae are imperfectly divided and therefore cause poor mixing.

It is preferable to obtain a perfect division and therefore an intimate mixture to carry them out with a high speed of rotation of the dividing and mixing members.

However, this results in a drawback that of dust emanation due to the structure of the materials to be mixed which are powdery and dry or slightly damp.

The present invention aims to obviate this drawback by producing a dividing device for mixing dry or slightly damp powder products by the use of which no dust emanation occurs.

To this end, the present invention relates to a divider and mixer device for dry or slightly moist powder materials comprising a rotary mixer divider assembly in a chamber provided with a supply port and a discharge port, said device being remarkable in that the supply orifice is provided with closure means of the distributor type and that the evacuation orifice is provided with closing means and / or a means constituting a baffle for the progression of dust , said means being a rotary endless screw in a cylindrical casing at the end of which is formed the discharge orifice which is thus distant from the mixer divider assembly.

Other advantages will appear on reading the description and on seeing the appended figures, given by way of nonlimiting example in which: - Figure 1 is an overview of the device according to the invention.

- Figure 2 is a sectional view along AA of the device according
the invention.

As shown in fig. 1 and 2, the device comprises a mixing chamber 1 containing a divider and mixer-2 assembly and associated with at least one storage hopper 3 of dry or slightly wet powdery materials at least one feed opening 4 of the mixing chamber 1 and at least one ev2 ~ cuation 5 member bringing the divided and mixed materials to an evacuation orifice 6.

The mixing chamber 1 is always kept closed at the feed opening by shutter members arranged in the form of a distributor, and at the discharge orifice 6 by a closing element provided means allowing the actuation of said element and / or by a device constituting a baffle, this role being played by the evacuation member, so that there is no emanation of dust out of the device during its operation.

The shutter members are constituted by at least three pallets 7 fixed on a horizontal shaft 3 by one of their longitudinal edge and spaced apart from one another, by the same angle.

Preferably, as can be seen in FIG. 2, the pallets 7 are four in number and it follows that the angle separating them is logically 90g.

The pallets 7 are rotated by the shaft 8 on which they are fixed in a horizontal cylindrical space 9, open on the side of the hopper 3 and on the side of the feed opening 4 shaped by the walls of said hopper .

The rotation movement of said pallets 7 is provided by a motor 10 provided with a speed variator II of known type allowing the speed of rotation of the pallets 7 to be adjusted.

The rotational movement of the pallets 7 is transmitted to a speed reducer 12 by belt, the said reducer 12 directly transmitting the rotary movement to the shaft 8.

The space between two pallets 7 is filled with powdery dry or slightly moist materials when it is oriented towards the opening of cylindrical space 9 communicating with the hopper 3.

The rotation of the pallets brings the quantity of dry or slightly wet pulverulent materials towards the other opening - of the cylindrical space 9 Bt the quantity of the said materials - falls by gravity into the mixing chamber l passing through feed opening 4.

The walls defining the cylindrical space 3, retain during the rotation of the pallets the amount of dry or slightly wet pulverulent materials.

During the rotation, there is never a direct relationship between the hopper 3 and the feed opening 4 thanks to the pallets 7 which continuously prohibit all relationships.

The storage hopper 3 consists of two side walls 13 and 14 shown in Figure 1; inclined towards each other and downwards in the upper part of the hopper 3, then vertical, parallel in the lower part of this.

Said walls 13 and 14 laterally delimit the feed opening 4.

In addition, the wall 13 carries in its vertical part and outside the speed reducer 12.

The shaft 8 of the pallets 7 is mounted between the walls 13 and 14 of the hopper 3 perpendicular thereto.

The walls 13 and 14 constitute the bearings of said shaft 8.

The shaft 8 is blocked in translation on the side of the side wall 14 by any known means.

The front 15 and rear 16 walls of the hopper 3 have an identical inclination to the side walls 13 and 14 visible in FIG. 2, so that all of the walls allow the guiding of dry or slightly moist pulverulent materials towards the cylindrical space 9.

The front 15 and rear 16 walls are curved so as to form together the cylindrical space 9 in which the pallets 7 rotate.

According to one preferred embodiment, the front wall 15 after the cylindrical space 9 is inclined and delimits the lower part of the supply opening 4.

Preferably, the rear wall 16 near the cylindrical space 9 is horizontal and delimits the opening 4 in its upper part.

The walls delimiting the feed opening 4 are thus shaped in order to provide a guide of the materials towards the opening 4 supplying the mixing chamber 1.

According to a preferred embodiment, the hopper 3 is bordered laterally by two identical support and protection elements 17 and 17 ′, vertical.

Said elements 17 and 17 ′ are fixed perpendicularly to one of the walls of the mixing chamber 1 and to the top of the hopper on the walls 13 and 14 of the latter.

The closure element at the discharge orifice 6 is constituted by the combination of a closure element 15 of the orifice 6 and by a device prior to the orifice 6 acting as a baffle, the so-called device being the discharge member 5 or by one of the said elements and devices.

The evacuation orifice 6 is formed at the end of a horizontal cylindrical casing 19 in which is placed the evacuation organ 5 of divided and mixed materials.

Said discharge port 6 away from the mixing element is preferably rectangular in shape and is oriented downwards.

The discharge member 5 is an endless screw in rotation with preferably a small clearance in the casing 19, the turns of which form a dust stop baffle.

The casing 19 extends the fox from the mixing chamber.

The orifice 6 for evacuation is thus distant from the mixing chamber 1, which avoids the discharge of dust emanating from said chamber through said orifice.

The worm 5 is driven in a rotational movement by a geared motor 20 placed at the end opposite to the discharge orifice 6.

The worm 5 acts in the bottom of the mixing chamber 1 over a great length so that the quantity of divided and mixed materials, discharged is maximum.

The sealed mixing chamber I is formed by two side walls 21 and 22 vertical, parallel then inclined towards one another and downwards in order to form the rounded bottom of the chamber 1 and on which the worm rests 5.

On the wall 22 are fixed the hopper 3 and the supporting and protective elements 17 and 17 '.

The feed opening 4 is formed in said side wall 22.

The front 23 and rear 24 walls are inclined towards each other and upwards in the upper part of the mixing chamber 1.

The front wall 23 is then vertical to the bottom of the chamber 1 and supports in its lower part the geared motor 20 actuating the worm 5.

Said geared motor 20 is placed outside said wall 26 and its output shaft animating the screw 5 passes through a practical orifice in the wall 23. S
The front wall 24 is then vertical over a small height and then is inclined forward and downward.

On its lower end is fixed the casing 19 of the worm screw 5.

The mixing chamber 1 has such a lower part in order to offer the worm 5 a large working surface.

On the end of the upper edges of all of these walls is fixed a horizontal wall 25 closing the mixing chamber 1 and thus ensuring the sealing thereof.

The mixing chamber 1 contains a rotary divider and mixer 2 assembly shown in FIG. 2.

Said assembly 2 consists of two concentric rotatable cages in opposite directions with respect to each other and with respect to a horizontal axis.

One of the said cages has an opening 26 opposite the feed opening 4 of the mixing chamber 1 so that the quantity of dry or slightly wet pulverized materials poured into said chamber 1 undergoes the entire action reverse rotations allowing division and mixing.

The dry or slightly wet pulverulent materials are poured into the opening 26 of the divider and mixer assembly 2, their division and mixing are done in Greek with concentric cages whose rotations are opposite.

The reverse rotations are of the same speed, preferably the linear speed varies from 15 to 35 mbtres / second depending on the dimensions of the device.

The divided and mixed materials leave the divider and mixer assembly by gravity and / or under the action of the centrifugal force created by the rotations of said assembly 2.

The cages of the rotary divider and mixer 2 assembly are constituted by several circular, parallel, rotary rings, relative to their same horizontal central axis and between which are fixed perpendicular along at least one circumference of said rings, parallel straight elements 27 to the axis of rotation and for example cross section of dirty squares.

The opening 26 of the divider and rotary mixer assembly is formed by a circular crown 28 of large diameter and large width.

Said ring 28 is close to the side wall 15 of the mixing chamber 1 in which the feed opening 4 is formed and parallel to it.

On the inside facing side of the mixing chamber
1 are fixed perpendicularly straight elements 27 along two circumferences close to the edges of the crown 28.

On the free ends of the straight elements 27 fixed on the circumference of larger diameter is fixed a crown 29 of small width but of large diameter.

The straight elements 27 shorter than the previous ones, fixed on the circumference of small diameter carry on their free hopper a driving crown 30.

Behind the crown 30 is arranged a crown 31 of larger diameter.

The crown 31 and the crown 29 are arranged in the same vertical plane.

The crown 31 has an outside diameter slightly smaller than the inside diameter of the crown 29 so that the said crown 31 rotates freely in the crown 31.

On a circumference close to the edge of the crown 31 are fixed straight elements 27 oriented towards the inside of the mixing chamber 1, carrying at their free end a crown 32 of small width.

The straight elements 27 carried by the driving crown 31 and the crown 32 rotate in the space defined by the straight elements 27 placed on the two circumferences of the crown 2d and in the opposite direction thereof.

The driving rings 30 and 31 rotate in opposite directions and are fixed on two different coaxial shafts each driven in rotation by a belt acting on a pulley secured to the aforementioned trees.

One of the shafts is driven by the motor 10 while the other is driven by a motor 33.

The motors 10 and 33 are carried by a horizontal caster 34 completely surrounding the mixing chamber 1 and constituted by aes beams and crosspieces.

The mixer and divider device having shutter and introduction of the material animated by a permanent rotation and an evacuation organ in the divided and mixed manner animated also by a permanent rotation allows the continuous treatment of the said matter.

The device as described makes it possible to divide and mix dry or slightly wet pulverulent materials in a closed cup without emanating dust out of the device and at high speed.

It goes without saying that the present invention can receive all arrangements and all variants without departing from the scope of this patent.

Claims (1)

 R1 / Divider and mixer for powdery materials  dry or slightly wet with a melan chamber  ge (1), containing at least one divider and mixer assembly  rotary (2), and associated with at least one storage hopper  (3), at least one feed opening (4) in mate  dry or slightly damp powdery rials and at least  an evacuation member (5) bringing the divided materials and  mixed towards an evacuation orifice (6), the said disposi  tif being characterized in that the mixing chamber (1)  is always kept closed, at the opening  supply (4) by shutter members arranged  lon the form of a distributor and at the level of the evacuation  by a device constituting a dust stop baffle. R2 / Divider and mixer for powdery materials  dry or slightly wet according to claim 1, charac  terized in that the shutter members are constituted by  at least three pallets (7) fixed on a tree (8) horizon  tal by one of their longitudinal edges and spaced one by  relative to the other at the same angle. R3 / Mixing divider device according to claim i, ca  characterized in that the device constituting the stop baffle  is a rotary screw (5) for evacuation in a coach  cylindrical ter at the end of which the opening (6) is arranged  evacuation. R4 / Divider and mixer for powdery materials  dry or slightly wet depending on the RI and R2 characterized  in that the pallets (7) are rotated by  the shaft (8) on which they are fixed in a space  cylindrical (9) horizontal open from the opening side  on the hopper side, conformed by the  walls of the said hopper. R5 / Divider and mixer for powdery materials  dry or slightly wet depending on the IR characterized in that  that the rotary mixer divider (2) assembly is constructed  killed by two concentric rotating parts in reverse direction  itself with respect to each other and with respect to an axis ho  rizontal of which one of the said parts has an opening  (26) located opposite the feed opening  of the mixing chamber so that the amount of ma-  dry or slightly moist powdery materials spilled  in the said room undergoes in its entirety the action of  reverse rotations allowing division and mixing. R6 / Divider and mixer for powdery materials  dry or slightly wet depending on the RI and R6 character  laughed at in that the parts consisting of several necks  coaxial parallel circular columns between which  are fixed perpendicularly along at least one circumference  ference of said crowns, straight elements (27)  parallel to the axis of rotation.