SU946673A1 - Classifier - Google Patents

Description

(54) CLASSIFIER

one

The invention relates to devices intended primarily for the separation into fractions of the size of raw ground cement sludge and can be used in other areas of the building materials industry, as well as in the beneficiation, silicate and chemical.

A device is known for enriching a bulk material made in the form of a cylindrical-body with a screw mounted coaxially inside, connected to a rotational drive and branch pipes tangentially mounted to the body for introducing separation media, enrichment material and removal of SR enrichment products.

The known device cannot be used for classifying the cement raw material sludge, when the fine dispersed product is ready.

Also known is a classifier of building sand and gravel, a connecting body with loading and unloading pipes, a cylindrical sieve and an Aint guide C2 coaxially installed.

Efficiently working to clean building gravel and sand from harmful impurities, the classifier is completely unsuitable for the classification of cement raw material sludge into fractions by size, when the fine dispersed product is ready.

In the well-known classifier, the supply of pulp occurs below the perforated cylinder, and then sand and pebbles, completely filling the sub-chamber, are forced to move upwards with an auger. At the same time, the circumferential speed of movement of the material inside the keiier is insignificant and drops sharply when the screw moves upwards.

Under such conditions of supply and movement of cement raw material sludge, its classification is impossible. Taking into account that slit-shaped knee sieves with a slit width between the grates of 0.3-0.8 mm are used to classify sludge, in a well-known classifier immediately after filling the supra cavity of the slit the sieves are clogged and the classification process does not occur.

In order to effectively classify the cement raw material sludge, the movement of its flow along the inner surface of a cylindrical or conical sieve should occur from top to bottom and by inertia. At the same time, the thickness of the layer of the moving ishamal flow must always be less than the distance between the inner generator of the sieve and the central wall of the helix, i.e. the subcameral chamber between the turns can be filled only for 2/3 of the channel cross section and not more. At the slightest creation of a head (pressure) in the sub-cavity, the classification of the sludge stops immediately. Such movement of the sludge can only be carried out by inertia and with a fixed helix. The aim of the invention is to increase the efficiency of the classification of cement-raw sludge and increase the productivity of the classifier according to: CRITICAL PRODUCT. . This goal is achieved due to the fact that the loading nozzle is installed in the upper part of the classifier, and the screw direction of the cylinder, which is rigidly connected to the housing, has a step between its sides, increasing from top to bottom, and the outer diameter of the guide to its inner diameter The diameter is 2.0-2.5. In addition, to increase the service life of the sieve, the casing is provided with a receiving cup with a lining ring inside, the height of which is 1.5–2 times greater than the initial pitch of the helical guide. The achievement of this goal is also facilitated by the fact that pulp flow guides are installed between the turns of the lower part of the screw guide. In FIG. 1 shows a classifier longitudinal section; in fig. 2 is a section A-A in FIG. The classifier includes a housing 1 on which a receiving cup 2 with a lining ring 3 inside is mounted on top, directly supported on a cylindrical sieve 4, which has the same internal diameter with it and is made in the form of vertically arranged grates 5 forming gaps between them. On top, the receiving cup is closed by a lid 6, and on the side is a loading nozzle 7, which has a shutter 8 for controlling the amount of ishama entering the classifier. Inside the cylindrical screen, a screw guide 9 is installed coaxially with it, the outer diameter of which is 2.0-2.5 to its inner diameter. The screw guide is rigidly fastened to the body, which has two discharge ports 10 and 11, respectively, for removal of the fine and coarse fractions. The pitch between the turn of the guide 9 is made upwards from 4WBaKfimiviCH from top to bottom, and its turns mck downward in the direction from the center of the guide to the periphery. Between the turns of the lower part of the screw guide 9, the guides 12 of the pulp flow are installed. Between the housing 1 and the cylindrical screen 5 there is formed an annular cavity 13. The classifier works as follows. Cement raw material sludge (or any other pulp) to be divided into two fractions by the pressure and with a certain speed is fed through the inlet 7 to the inner surface of the lining ring 3. Under the action of the developed centrifugal forces, the sludge moves along the helical surface guide 9 presses against the sieve 4 and begins to be classified. The fine fraction passes through the slots of the cylindrical sieve 4 into the cavity 13 between the sieve | 4 and the body 1 and through the pipe 10 is removed from the classifier. The slurry, as it moves along the helical surface 9, becomes coarser due to the removal of the fine fraction from it and, of course, less mobile. The speed of its movement tends to decrease, but it remains optimal due to the step between the turns of the screw guide 9 gradually increasing downwards. Since the turns of the screw guide 9 are inclined in the direction from the center of the guide 9 to the periphery, this increases the degree pressing the sludge flow against the surface of the sieve 5. The guides 12 between the turns 9 of the guide 9 facilitate the movement of the sludge flow towards the inner surface of the sieve. In the invention, the reduction in the initial speed and supply pressure of the original sludge is achieved by optimally selecting the diameter of the cylindrical sieve and the number of turns of the guide 9. It is known that the centrifugal force pressing the sludge flow to the sieve is calculated by the formula D where m is the sludge flow mass on the considered section of the cylindrical sieve; V is the velocity of the slurry flow; R is the radius of the cylindrical sieve. Therefore, in order to maintain the required value of the centrifugal force, it is possible to reduce the speed of the sludge flow and the radius of the cylindrical sieve in a corresponding manner. The necessary way of passing the shaft is provided by selecting the appropriate number of turns of the helical guide.

Claims (3)

Claim 1. A classifier for dividing 20 pulps into fractions, including a housing with loading and unloading nozzles, inside which a cylindrical sieve and a screw guide are coaxially mounted, distinguishing it in that, in order to increase the efficiency of classification of cement-raw material sludge and increase the performance of the classifier according to the feed product, the loading nozzle is installed in the upper part of the classifier, and the screw guide, rigidly connected with the body, has a step between its turns, increasing from top to bottom, with this ratio of the outer diameter of the screw guide to its inner diameter is 2.0-2.5. 2. The classifier according to claim 1, characterized in that, in order to increase the life of the sieve, it is equipped with a receiving cup with a lining ring inside, the height of which is 1.5-2 times greater than the initial step of the screw guide. 3. The classifier according to paragraphs. 1 and 2, characterized in that, between the turns of the lower part of the screw guide mounted pulp flow guides.