RU35247U1 - Spiral classifier - Google Patents

Description

Spiral classifier

The utility model relates to devices intended for separating granular materials by size in ascending flows of water, namely, classifiers with gravity separation and forced unloading of sand, and can be used in mining, construction and other industries.

In addition to separation by size, mechanical classifiers can be used for washing clay sludges and dewatering materials.

The devices of this type include spiral classifiers, in which the device for transporting sand is made in the form of a spiral.

In the general case, the spiral classifier consists of an inclined semi-cylindrical trough, in which one or two rotating shafts with spirals mounted on them are placed, the number of which, along with other factors, determines the performance of the classifier. The classifier is also equipped with a mechanism for lifting spirals, has a drain threshold and devices for supplying the starting material and separation medium, as well as for unloading the products of enrichment (Reference for ore dressing. In 3 volumes, OS Bogdanov. T. 1. Preparatory processes. M., Pedra, 1972, S. 237-240).

Spiral classifiers have a number of technological and mechanical advantages over other mechanical classifiers. The mixing action of the spirals is more relaxed, as a result of which the swirl of the pulp is less than, for example, in a rack classifier. To ensure normal operation, the power of the classifiers is distributed evenly over its entire width. (Reference for

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IPC 7 to 03 to 5/52

ore dressing. In 3 volumes, O.S. Bogdanov. T. 1. Preparatory processes. M., Nedra, 1972, p. 254). For classifiers with two or more sirales, this is technically realized by feeding pulp (power) directly into the space between the spirals. So, in A.S. USSR No. 778803 (publ. 11/15/1980) describes a device for mineral processing, in which the material to be enriched is loaded through estrus into the space between the screws rotating in opposite directions. In a multi-spiral dehydrator according to as USSR No. 942796 (published July 15, 1982) in the lower part of the classifier above the chamber between the spirals there are two loading vertical wells with slurry receiving funnels into which the loaded pulp enters.

The closest in technical essence to the claimed classifier is a two-spiral classifier for separation by size of the products of grinding the aggregate mill-classifier (AS USSR No. 755307, publ. 08/15/1980). The classifier includes a trough with an drain threshold installed at an angle to the horizon, an unloading Sand window and a Sand gutter located under it (means for dumping sand), spirals located in the trough, rotated by the drive, and a mechanism for lifting the lower parts of the spirals, while half of the unloading sand window , farthest from the mill, drowned, and its corresponding spiral is equipped with strokes. In such a classifier, a device for feeding the pulp to the classifier and a device for draining the water-sludge mixture (drain threshold) are placed in the lower end part of the classifier trough, and the pulp is fed in a direction parallel to the axes of the spirals.

This invention provides for the separation of the pulp to be classified into two classes: solid particles having a particle size below the boundary unit, while in suspension, are discharged through the drain threshold (watery fraction), and solid particles having a particle size above the boundary unit (directly sand) precipitate in

the sediment at the bottom of the trough is captured by rotating spirals and does not move upward, where the sands moved by each of the spirals are combined and fed through a common discharge chute to the mill for grinding. The device provides an increase in the output of the sands of the classifier by increasing the angle of inclination of the sand trough, but it does not solve the problem of separating sand separated from the watery mixture by size into fractions on the classifier.

The objective of the utility model is to develop a spiral classifier that is simple in constructive implementation and uses, which separates sand by size into fractions on the classifier by arranging the flow of pulp in the direction perpendicular to the axes of the spirals.

The problem is solved by the proposed spiral classifier, including a trough installed at an angle to the horizon with two transporting spirals installed in it, mounted for rotation from the drive, a mechanism for lifting the lower parts of the spirals, a pulp feed device and a drainage device located in the lower part of the classifier watery mixture, as well as a means for dumping sand located in the upper part of the classifier, in which, unlike the known device, The pulp supply and drainage mixtures are located on opposite side walls of the trough, the pulp feeding device is installed above the discharge level, and the sand discharge means are separate gutters for discharge of sand fractions of different sizes from the corresponding spirals.

The essence of the utility model is illustrated by the drawing, where the figure shows the proposed double-spiral classifier (general view from above).

The device includes a trough 1 installed at an angle to the horizon with two transporting spirals 2, a device 3 for feeding pulp to the classifier and a device 4 for

discharge of the watery mixture, as well as troughs 5 and 6, for discharge, respectively, of coarse and fine fractions of sand.

The placement of the device for feeding the pulp above the discharge level in the attached figure is not reflected.

In the proposed device, devices for feeding the pulp and for draining the aqueous mixture can be made, in particular, in the form of pipes for feeding the pulp and for the removal of the aqueous mixture, respectively.

The device operates as follows. The pulp to be separated (a mixture of water and material) is fed through a pulp feed device 3 located in the side wall of the lower part of the trough 1 of the classifier. After turning on the classifier, spirals 2 using a drive (not shown in the drawing) are driven into rotation. Large particles of sand immediately fall to the bottom of the trough 1 and are picked up by the blades of the spiral 2, which are moving along the pulp of the first along the pulp stream, which move the larger sand fraction upward along the inclined trough 1 for dehydration and discharge from the classifier through the chute 5 to output the large fraction. The pulp with the remaining finer fraction of sand moves towards the drain hole - device 4 for draining the water-sludge mixture. In the zone of another spiral 2, farther from the pulp feeder 3, a fine sand fraction is deposited on the bottom of the trough 1, which is captured by the blades of this spiral and is directed upward along the inclined trough 1 for dehydration and discharge from the classifier through the trough 6 to withdraw the fine fraction .

The solid particles remaining in the pulp after precipitation of the bulk sand in the separation process in the classification zone, in suspension, are discharged through the device 4 for draining the water-water mixture.

to drain the water-sludge mixture in the proposed way, the pulp is fed into the classifier in the direction perpendicular to the axes of the spirals, which causes the sand to be scooped up by spirals into two fractions that differ in size: the larger fraction falls in the spiral zone, closer to the pulp feeder, and finer, the fraction falls in the zone more remote from the specified device spiral. This allows you to organize a separate output of products for each of the spirals and get at the exit from the classifier two fractions of sand, varying in size.

In addition, if necessary, from a drainage water with a silt fraction, a third finely divided fraction can be separated by known methods, for example, in a sump, using filters or in a hydrocyclone.

In accordance with the proposed utility model, a pilot industrial model of a spiral classifier was manufactured, tested to separate sand into fractions. As a result, sand with an average fractional particle size of 200-500 microns was obtained from a sand chute for a large fraction, and sand with an average fractional particle size of 90-300 microns was obtained from a sand chute for a small fraction.

The proposed device is simple in design and reliable in use.

Claims (1)

A spiral classifier, including a trough installed at an angle to the horizon with two transporting spirals placed in it, mounted for rotation from the drive, a mechanism for lifting the lower parts of the spirals, a device for feeding the pulp into the trough and a device for draining the water-water mixture placed at the bottom of the classifier, and also a means for discharging sand, located in the upper part of the classifier, characterized in that the devices for feeding pulp and for draining the aqueous mixture are located on from the opposite side walls of the trough, and the pulp feeder is installed above the drain level, and the sand discharging means is separate gutters for discharging sand fractions of different sizes from the corresponding spirals.