RU2031976C1 - Apparatus for pieces pickling - Google Patents

Abstract

FIELD: metal pieces pickling. SUBSTANCE: apparatus has flap bottom cylinder, made of shaped metal sheet and reinforced with belts, and lifting and transporting mechanism. Apparatus is provided with mounted inside the cylinder discharging tool, made as perforated spiral chute, outer diameter of which is equal to inner diameter of cylinder, and with rod, that passes through center of discharging tool. In the case inner edge of chute embraces the rod. EFFECT: apparatus increases productivity and quality of pickling, decreases metal losses. 1 dwg 1 tbl

Description

 The invention relates to devices for chemical surface treatment of metals, in particular to baskets for etching small, heterogeneous in structure metal products and industrial wastes (revolutions).

 In the manufacturing process of small-sized parts, revolutions are formed in the form of press residues, shavings, non-dimensional blanks, blanks rejected by mechanical properties, samples after mechanical tests, etc.

 These revolutions have technological contaminants on the surface, which are removed by etching their surface, for example, in a nitric acid solution at room temperature. To do this, in production, revolutions are most often loaded into baskets made of a perforated sheet, and then, using a hoist, they are placed in an etching bath. Etched turns are washed in water, dried, and then used in the mixture for smelting ingots in smelting furnaces.

 A device for washing parts [1] is known, comprising a washing chamber, a spiral guide and a vibration drive, the washing chamber being made in the form of a vertically arranged cylindrical hopper through which an unbalanced shaft passes.

 This device is notable for its complexity of design and significant energy consumption during operation. The effectiveness of chemical cleaning of parts in this device is ensured by moving them along a spiral guide with simultaneous stirring.

Known vibration bin for chemical treatment of the surfaces of small parts [2], which houses three chambers for various purposes for chemical treatment (and drying) with one spiral vibrator, the angle of inclination of -3 ^about .

 Such a vibratory hopper is notable for its complexity of design and significant energy consumption. The horizontal arrangement of the chambers of the vibro-bunker reduces the efficiency of use of production facilities in comparison with vertical devices. The effectiveness of chemical cleaning of parts in a vibratory hopper is achieved in the same way as in the above device.

 A device for washing, drying and preserving parts [3] is also known, including a housing with supports mounted one above the other to accommodate workpieces, devices for loading and reloading parts from one support to another, and collectors for spraying a working agent onto parts, moreover supports for accommodating the workpieces are made in the form of drive perforated disks equipped with a rim around the periphery.

 This device is also difficult in design and energy-intensive in operation. The effectiveness of chemical cleaning of parts is achieved through their blasting and moving from support to support.

 A device [4] is known for storing products in bulk during their chemical or electrochemical processing by immersion in one or more baths, containing a drum for storing these products, which can rotate on a frame that serves as its basis. The device is characterized in that the drum axis is vertically or at some angle, and its side wall is formed by at least one lower fixed shell and at least one rotating shell located above, while the base is formed by a movable element, connected to controls that allow the extraction of products from below and loading - from above. In addition, the device has a mechanism for mixing products.

 The complexity of the design, the presence of many moving units and parts reduce the reliability of this device. The effectiveness of chemical cleaning of products provides their mixing and the use of electrochemical processing.

 Closest to the proposed is a device for etching products [5], mainly revolutions, comprising a housing made of a perforated sheet in the form of a vertical cylinder with stiffeners and with eyes for lifting and transporting devices, and a hinged bottom.

 This device allows you to process simultaneously up to 600 kg of products or revolutions. It is distinguished by its simplicity of design, reliability and significantly lower energy costs associated only with the transportation of revolutions, for example, a hoist, to the etching bath and vice versa.

 However, this device does not provide high-quality etching of small, heterogeneous in the structure of revolutions. Tight packaging in a basket of small revolutions with a highly developed surface leads to the fact that the revolutions located in the center of the basket are not etched, and high-quality cleaning of the revolutions surface from technological pollution does not occur due to the fact that the etching solution is not accessible to them. Turnovers have to be sorted and re-etched to achieve the required surface quality, which leads to reduced productivity, increased labor costs, increased metal losses due to the need for re-etching.

 The present invention is aimed at improving the productivity and quality of etching of small, heterogeneous in the structure of revolutions by providing access to the etching solution to any surface of the revolutions loaded into the device.

The specified task is solved as follows:
In contrast to the known device for etching products, mainly revolutions, comprising a housing made of a perforated sheet in the form of a vertical cylinder with stiffeners and with eyes for a lifting and transport device, and a hinged bottom, the proposed device is equipped with a trigger made in the form of a perforated spiral tray placed inside the cylinder and a rod for fixing the bottom passing through the center of the descent, while the outer diameter of the descent is equal to the inner diameter of the cylinder, and the inner The lower edge of the descent covers the shaft.

 It is known the use of helical descent [6] for the handling of bulk and piece materials in the chemical industry at processing plants, etc.

 However, the use of a fixed helical descent made of perforated material in etching devices has not been identified.

 The proposed device combined the advantages of a mesh basket-shelf, which allows, as a result of layer-by-layer placement of the processed product, to supply an etching solution to each of its particles in sufficient quantities and to qualitatively clean it of technological impurities, and the advantages of the prototype, which allow easy unloading when opening the bottom (and when the bottom is closed) - easy to load)

 The drawing schematically shows a device for etching.

 The device consists of a cylinder 1 made of a perforated sheet reinforced with belts 2, a hinged bottom 3, eyes 4 for transporting the device, for example, with a hoist. Inside the cylinder, a spiral descent 5 is mounted in the form of a spiral tray made of a perforated sheet (or mesh), the outer diameter of which is equal to the inner diameter of the cylinder 1, and the inner edge covers the rod 6 passing through the center of the descent. Before operation, the device is inspected and its bottom 3 is closed. In the device small, non-uniform in structure revolutions are poured from above with dosed portions, which, under the influence of their own weight, slide down the spiral channel of the spiral descent 5 down the device and evenly fill it all bemsya. In this case, the revolutions are evenly laid on a spiral tray. After that, the device with turns by hooks of transport cables (not shown) is hooked to the eyes 4 and lifted up, transported to the pickling bath and lowered into it. The pickling solution through the holes in the cylinder 1 and in the spiral tray enters the surfaces of revolutions, thereby achieving high-quality dissolution of technological contaminants. After the end of the etching cycle, the device with revolutions is removed from the etching bath and sequentially placed in a bath with cold and hot water to remove etching sludge from the surface of revolutions, and then placed on the platform for drying revolutions. After drying, the device with revolutions is placed over the container, the bottom of the device 3 is opened, and the revolutions, under the influence of their own weight, slide along the spiral tray and pour out into the container.

 Effective cleaning of revolutions (production waste) in the proposed device occurs with the usual immersion of the device loaded with revolutions in the bath without using additional energy sources, due to the uniform distribution of revolutions of 5-105 mm in size on the spiral groove tray.

 To obtain the comparative characteristics of the devices according to the prototype and the proposed technical solution, the following work is carried out.

 In the device according to the prototype (without screw descent) with a cylinder diameter of 420 mm and a height of 700 mm, 600 kg of revolutions of 5-105 mm in size are loaded from steel 10 coated with zinc melt. Then the device with turns is placed in the pickling bath and etched in a nitric acid solution with an acid concentration of 200 g / l at room temperature for 3 hours. After that, the device with turns is placed sequentially in baths with hot and cold water and the turns are dried in device in the air. Then the revolutions are unloaded from the device after opening the hinged bottom in the crates. Etched revolutions are sorted, unpickered revolutions are sent for re-etching, and revolutions cleaned from technological impurities are sent to prepare the mixture for smelting ingots.

 In parallel with this, etching of the revolutions is carried out in the proposed device, the perforated cylindrical body of which has the same geometric dimensions as the prototype. A helical descent is welded inside the cylinder in the form of a spiral tray made of perforated steel sheet with a thickness of 2 mm with a pitch of 180 mm. The spiral covers the central rod (50 mm in diameter), on which the hinged bottom is mounted. The diameter of the perforations in the cylinder and spiral tray is 2-3 mm.

 This device is loaded with 600 kg of revolutions of 5-150 mm in size, which by gravity fill the entire working volume of the device by a spiral tray. Then the device with revolutions is installed in the etching bath and the revs are processed using standard technology. After drying, the revolutions are unloaded from this device by opening the hinged bottom. Turnovers, by gravity moving along a spiral tray, fill the crate. During this work, the performance of the device is recorded. The quality of etching is evaluated by selecting chips from their surface and then analyzing it for zinc content. Loss of metal during etching is determined due to the difference in weight of special samples without coating before and after etching.

 The results of the study are shown in the table.

 Analysis of the data in the table shows that the proposed device, in contrast to the prototype, when etching small, heterogeneous in terms of structure of revolutions, has higher productivity (200 kg / h instead of 160 kg / h according to the prototype due to eliminating the need for repeated etching of revolutions), higher quality etching of revolutions (the zinc content on the surface of etching revolutions corresponds to their content in the conditioned metal — less than 0.003 wt.%), lower metal losses during etching (3.3 g / kg of revolutions instead of 4.1 g / kg revolutions of the prototype).

 The device has been tested under industrial conditions for processing revolutions contaminated with zinc, with a positive result.

Claims (1)

 DEVICE FOR ETCHING PRODUCTS, mainly revolutions, comprising a housing made of a perforated sheet in the form of a vertical cylinder with stiffeners and eyes for a lifting and transport device, and a hinged bottom, characterized in that it is provided with a trigger made in the form of a perforated spiral tray, placed inside the cylinder, and a rod for fixing the bottom passing through the center of the descent, while the outer diameter of the descent is equal to the inner diameter of the cylinder, and the inner edge of the descent the rod.

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