SU980765A1 - Thickner - Google Patents

Description

The invention relates to a thickener lm and can be used in apparatus for chemical industry, non-ferrous and ferrous metallurgy. Known sump, comprising a cylindrical body with a conical bottom. Inside the casing, a rowing device is mounted on the vertical H.OM shaft, rigidly connected to the shaft 11. The disadvantage of this design is the rigid fastening of the rower device to the shaft. Since sludge from alumina production is prone to self-consolidation, the bed of sludge under the paddles of the rowing device grows during the operation of the thickener, the friction of the thickeners of the thickener on the bed FROM the sludge increases dramatically, the load on the rotational drive increases sharply. In. avoidance of drive-rotation breakdowns include lifting mechanisms and raise the rowing device by 50-75 mm. So at the same time, a thickener with rakes fixed on the shaft requires a lifting mechanism, a rotational drive is required with a large torque, and, consequently, a greater weight and size. The closest in technical essence and the achieved result to the proposed is a thickener, including a housing with a central shaft, equipped with levers rigidly connected with it, tines with scrapers, a coupling system of tines with levers and a rotation drive va-f2. The disadvantage of this design is the impossibility of its use in alumina production for thickeners with peripheral discharge of a condensed product, since the tines of this thickener are pivotally fixed in the center of the thickener, as the bed is formed from the sludge, they will create a reverse cone of the sludge inside the bed, which is significant complicates the transport of sludge from the center of the thickener to the periphery, as well as its selection. In the alumina industry, there has been a tendency to build thickeners with a large diameter (40 m and more) with peripheral discharge of a thickened product due to the low cost and complexity of flat foundations. However, these thickener designs with peripheral discharge of the thickened product have a number of disadvantages listed.

The purpose of the invention is to provide peripheral discharge of the condensed product.

The goal is achieved by the fact that in a thickener, including a housing with a central shaft, fitted with levers, rigid treads with scrapers, a coupling system of tines with levers and a shaft rotation drive, the coupling system of the tines with levers is made in the form of several vertical cables and at least four pairwise paired inclined cables located in planes perpendicular to the planes of the scrapers.

FIG. 1 shows a thickener, a cross section; in fig. 2 - lever with hanging tine, top view; in fig. 3 - scraper, side view.

The thickener consists of a cylindrical body 1. Bottom 2, as a rule, is flat in the peripheral thickener. The alumina production thickener is closed by the roof 3, since the temperature of the pulp is about 100 ° C. Above the cover there is a drive for rotating 4 the shaft 5 of the paddle device. The paddle device includes radial levers 6 rigidly connected to the shaft, on which the tines are suspended. Each tine consists of a rod 7 and scrapers 8 fixed on it. Tines nof are hung on the levers with vertical cables 9. Slanted cables 10 connecting the tine with the lever are pairwise parallel and located in planes perpendicular to the planes of the scrapers. The number of oblique troso not less than 4.

The thickener is equipped with a pipe for feeding the pulp 11, a receiving cup 12, fittings 13 for selecting the clarified product and fittings 14 for selecting the condensed product.

The device works as follows.

The original pulp is fed through pipe 11 into the receiving cup 12 and spreads along the thickener in radial directions. Under the action of gravity, the pulp is separated into a clarified product — an aluminate solution, which is withdrawn through nozzles 13, and a thickened slurry product, which is transported by tines to nozzles 14. Drive 4 through shaft 5 and rigidly connected rachags 6 rotates tines. Torque from the drive is transmitted to the tines through a system of cables.

I When the drive is not connected, the tine arms hangs on the arms b, supported by vertical cables 9. Scraper tines are parallel to the bottom, since inclined cables 10 interfere with tilting the tine in one direction or the other.

With the drive running, in the pulp-filled thickener, the scrapers 8 transport the sludge falling on the bottom 2, on-periphery to the fittings 14. In this case, the resistance forces of the cuttings, as well as the rubbing of the scrapers on the bed, gradually forming on the bottom, force the tine back and to the center thickener. The resultants of these forces lie in the planes perpendicular to the planes of the scrapers

When the tine is deflected, the vertical cables 9 will loosen, and the inclined cables will tighten, the tines' scrapers will still be parallel to the bottom. The more the tine will deviate, for example, with an increase in the density of the condensed product, the more torque will be transmitted to the tine, i.e. The delivered system automatically adjusts the torque developed by the drive.

If large pieces of sludge fall under the tine, it will bend and crush them. Such a thickener does not need a lifting mechanism. Since the levers are raised above the bottom, they overgrow more slowly. The tines that are found in the crs eHHOM product are compact, their bars have a small diameter, since they are a beam that has several support points along its length.

Claims (2)

1. Kasatkin A.G. Processes and apparatuses of chemical technology, M., Himi, 1971, fig. 1-4, p. 190-192. 2. US patent 3295835, cl. 259-108, 1968 (prototype).