SU1361114A1 - Unit for utilization of rolling mill scale - Google Patents

Abstract

The invention relates to a technique for the treatment of sewage sludge from rolling mills of ferrous and nonferrous metallurgy enterprises, and can be used in machine building and other industries. The purpose of the invention is to increase the efficiency of the capture of small scale, as well as an increase in the duration of the working cycle and an increase in the productivity of the installation. The installation contains a primary storage compartment 1 with a grab 2 and a hopper 3 with a drainage system made in the form of longitudinal trays 17 located along the entire length of the hopper 3 and equipped with a grill in the upper part. Downstream of the grate along the walls of the tray 17, the flushing lines 19 are placed. The thickener 13 is installed after the secondary bis sump using the pipe 14 with the pump 15 is technologically connected to the sprayer 16. The sprayer 16 is mounted on the grab 2. The grab moves over the entire surface of the hopper 3. fine scale on the surface of large. The implementation of the drainage system of the proposed construction ensures the prevention of clogging of the trays 17 of dross, i.e. reliability of work and, therefore, duration of an operating cycle increases. 4 il. i (L with O5 4

Description

. one

The invention relates to a technique for the treatment of sewage sludge from rolling mills and can be used in black and color plants.

metallurgy, in machine building and other industries.

The purpose of the invention is to increase the efficiency of the capture of small scale, as well as increase the duration of the operating cycle and increase plant productivity.

FIG. 1 shows the proposed installation, a general scheme; in fig. 2 - the location of the drainage channel at the exit from the bunker; in fig. 3 is a section A-A in FIG. 1 (location of channels in the dross bin); in fig. 4 — node I in FIG. 3 ..

The installation consists of a primary clarifier 1 with a grab 2 and a hopper 3 for descaling the scale. The primary settling tank 1 is connected to the secondary settling tank 6 by means of process piping 4 and pump 5 Another group of technological piping 7 and pump 8 - connect the ethereal settling tank 6 with the cooling unit 9, from which the pipe 10 is connected to the rolling mill units, which are connected with primary clarifier 1 through channel 11.

Secondary sump 6 pipelines 12 is connected to a thickener 13, which pipe 14 C - pump 15 is connected to the sprayer 16 installed on the grapple 2,

The drainage system of the bunker 3 in the proposed installation is made in the form of, for example, longitudinal trays 17 located along the entire length of the bunker and in the upper part equipped with a grate 18. Underneath the grate 18 along the walls of the tray 17 are placed perforated washing pipes 19. The grate 18 is placed on the sides of the trays 17.

Between the grate 18 and the flush pipelines 19 along the walls of the trays 17 there are peaks 20, for example made of metal or similar dense material, designed to eliminate scale removal from the hopper to the pipe 19. At the outlet side of the tray 17 from the hopper 3, the peak 20 covers the entire width channel.

The installation works as follows.

Water contaminated by scale on rolling mill units, kana142

11 enters the primary clarifier 1, where it is freed from coarse particles 0.25–40 mm in size and the second secondary clarifier 6 is transported through technological pipelines 4 by pumps 5. In the latter, the water is cleaned from small particles of scale 0.05–0.25 mm and the pump 8 through the process piping 7 is supplied to the cooling unit 9, and from there to the rolling mill units through the pipeline 10.

A coarse scale retained in the primary clarifier 1, the grapple 2 is discharged into the bunker 3, where it is dehydrated. The fine scale retained in the secondary clarifier 6 is transported via conduit 12 to the thickener 13. The degree of thickening of the pulp in the thickener 13 is regulated depending on the amount of coarse scale in the bunker. When it is more fully filled, the pulp in the thickener is subjected to less thickening. When unloading coarse scale from the bunker, the degree of thickening of the slurry pulp from the secondary settling tanks increases. This adjustment of the degree of condensation is carried out in order to maintain high productivity and at the same time prevent the removal of scale from the bunker to the primary clarifier 1. Then the sludge slurry by pump 15 through line 14 is pumped to the sprayer 16 mounted on the grapple 2. The atomizer 16 allows to distribute small scale uniformly over the surface large due to the fact that it moves over the entire surface of the bunker 3. At the same time, a single section of the silo is seeded to mud and, as a result, decreases The rate of filtration of water or a sharp increase due to backwater in certain places, and hence an increase in the small scale carried out of the bunker in these places.

A coarse scale absorbs not only fine scale on its surface but also a significant amount of oil contained in the sludge. However, due to the fact that the ratio of coarse scale, located in the bunker.3, containing a small amount of oils (0.1-0.3%), and small oily scale, supplied after concentration from the secondary structures to the bunker, em (10-1) - (15-1), content

oils in a mixture of coarse and fine scale is 0.8-1.3%,

Excess moisture, passage through the scale in the bunker, gets into the sub-drainage chute 17, and then into the primary settling tank 1. In this case, the filter element is the scale found in the bunker 3, and that scale that passes through the grid 18 and it settles in tray 17. The main part of the fine scale is retained in the upper layers by loading the hopper. Only individual particles penetrate below. It is not possible to make a full discharge of scale from the bunker, since in this case, small scale gets into the sub-bunker drainage trays and quickly clogs them. But in this case too, the scale in the trays is a filter element,

In order to flush the drainage system, clarified water is supplied from a pipeline to supply water to the rolling mill through a pressure pipeline. To facilitate flushing along the drainage channel, perforated pipes 19 are laid. They are located on both sides of each tray in the upper corners under the removable grill. The tray, when it leaves the bunker 3, is covered with solid canopies 20 to prevent the removal of fine scale when the bunker is completely empty. The grilles and visors are removable to allow manual cleaning of trays in the event of the formation of dense deposits in the trays.

From the bunker, the mixture of coarse and fine scale is removed by means of a grab and transported to the charge-preparation plants of metallurgical units. During emptying, the bunker is replenished with large scale from the primary settling tank, on the surface of which thickened sediment from the fine scale of secondary settling tanks is distributed.

The advantage of the installation is that fine scale from the secondary settling tank after the thickener is fed through a pipeline, which is connected with a flexible hose to a spray gun installed on the grab. The grapple is moved throughout the entire bunker area. This makes it possible to release fine scale from the primary settling tank to any point on the surface of the large scale

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20

25

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in the bunker. Such a release allows eliminating the slimeing of individual areas in the bunker on the surface of coarse scale and thereby increasing the filtration rate, as well as eliminating the possible dramatic increase in the filtration rate due to backwater in certain places. The latter can lead to the removal of fine scale into the primary settling tank.

The advantage of the installation is also the presence of a thickener in its scheme. The thickener, located between the secondary sedimentation tanks and the bunker, is used as an apparatus with which the plant capacity is adjusted by providing different degrees of thickening of the slurry pulp. Such regulation is carried out by increasing or decreasing the degree of thickening of the pulp with, respectively, a smaller or larger layer of large scale in the bunker. In this case, regardless of the coarse scale layer, high quality of the mixture of scale, as well as the filtrate discharged to the primary settling tank of the water supply system, is achieved. Thus, the plant productivity is increased, since its dependence on the technological need for periodic scale removal from the bunker is eliminated. i 5 Installation advantage is

improved drainage system. Drainage trays are located below the level of the bottom of the bunker and at the level of the bottom of the bunker are closed with a grid that performs a supporting function.

The hopper is loaded with a large scale, taken out by a grab from the primary / final clarifier. A portion of the scale passes through the grate into the sub-canal channels, sludge slurry is deposited from the secondary sedimentation tank, discharged onto the surface of the large scale, filtered, and the filtrate loids 50 into the sub-drainage trays and discharged into the primary settling tank. In the case of complete discharge of scale from the filtering bin, the load for small scale is that scale that was deposited in the bunker trays, ° To prevent clogging of all scale that was deposited in the channels, or the removal of small scale in the primary clarifier part of the channel when exiting

40

the bunker is closed not by a grate, but by solid metal shields.

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The advantage of the installation is also

availability in drainage trays

perforated washing pipelines. To prevent the perforation of the percolation of the scum piping lines coming from the hopper, they are covered on top with solid metal canopies. Wash water is supplied from a pressure line, a sub-boat that supplies water to the mill. The dross that has settled in the tray is washed with water. At the same time, small scale is squeezed in and together with the washing water it enters the primary settling tank for cleaning,

The use of the invention allows to simplify the installation and operation of the installation, significantly reduce the cost of operating the dewatering equipment.

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Claims (1)

Invention Formula Plant for utilization of mill mill scale containing a primary settling tank with a grab and a bunker with a drainage system, a sprayer, a secondary settling tank, a cooling unit, process piping and pumps, in order to increase the efficiency of small scale formation, as well as increase the working time Cycle and 11th installation performance, the spreader is placed on the grab, and the drainage system of the bunker is made in the form of trays located along the entire length of the bunker, with the top of the lattice and flushing conduits arranged along the tray wall, the installation is provided with a thickener established after the secondary clarifier and process pipelines connected to the spray gun. ///////// Fig2 Aa :.: - / GR EZGwZGTEZ Fig.Z FSM Editor A.Shishkin Compiled by L. Sukhanova Tehred MD SchykKorrektor V. But ha Order 6191/26 Circulation 851 VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Production-printing enterprise, Uzhgorod, Projecto st., 4 Subscription