RU2221084C2 - Method of cleaning greasy scale and device for realization of this method - Google Patents

Abstract

FIELD: environment control. SUBSTANCE: proposed method includes preliminary dehydration of scale, loading of washing reservoir, hydrodynamic washing with heated washing solution, discharge of coarse-dispersed scale and removal of oil- containing emulsion and contaminated washing solution followed by phase separation of runoffs at separation of oil, cleaned washing solution and sludge containing finely-dispersed scale; cleaned washing solution is directed for preheated use in process. In the course of preliminary dehydration washing layer is formed from polydispersed scale. Prior to loading oil-containing scale, hydrodynamic mode is set in washing reservoir which corresponds to terminal velocity of particles in height of conical portion of washing reservoir depending on their size; this mode is maintained by continuous circulation of part of washing solution in washing reservoir at addition of clean washing solution. Phase separation of runoffs is performed in phase separation apparatus made in form of multi-section separator. Coarse-dispersed scale cleaned in washing reservoir and sludge removed from multi-section separator are dried with heated air. EFFECT: enhanced ecological safety; waste-free cleaning process; reduced losses of iron; reduced power requirements. 17 cl, 1 dwg

Description

 The invention relates to environmental protection, in particular to the cleaning of oily scale, which is a waste of metallurgical production, and can be used in all industries where it becomes necessary to clean the polydisperse material from hydrocarbon pollution.

 In the metallurgical industry, production wastes account for 1/3 of the total output. The bulk of them is oily scale formed during the rolling of sheets, pipes, wire drawing, hardware production, etc.

 With the existing methods for cleaning oil-containing scale, a large amount of oil-and-oil-containing wastewater is formed, including the precipitation of finely dispersed scale, the amount of which on modern rolling mills is 20-40% of the total generated. Oiled and dehydrated iron-containing sludge loses its flowability, is capable of caking, and adheres to gutters, hoppers, and metering devices. It is almost impossible to dispose of such sludge without preliminary treatment. Half of the fine scale is dumped into the dump and sludge collectors, although they are valuable metallurgical raw materials.

 According to the Nizhny Tagil Metallurgical Plant (NTMK), 1.3 million tons of oily scale accumulated in its dumps, 1 million tons at the Pervouralsk Novotrubny Plant, more than 2.5 million tons at Severstal OJSC, etc.

 It is possible to obtain various types of products from sludge waste and oily scale for subsequent reuse in blast furnaces and steelmaking units, as well as mining and processing plants.

 Oiled scale contains more than 80% of iron, so its utilization will reduce the cost of production of the metallurgical industry by about 30%.

 There is a method of disposing of oily scale and pickling solutions, which are waste products of metallurgical production, and processing them into red iron oxide pigment used in paint and varnish and other industries.

 The technological process of utilization of scale with obtaining iron oxide pigment consists of the following stages: preparation and restoration of scale; dissolution of iron with sulfuric acid; pigment synthesis; obtaining a return of sulfuric acid.

Oily and wet scale after separation of mechanical impurities is fed for drying into a rotary tube furnace. The mixture in the oven is dried by the combustion products of natural gas at a temperature of 150-200 ^o C.

Dry scale enters the inertial cone crusher. Coke dust is supplied there, which is used for the subsequent reduction of iron. The milled mixture of scale and coke dust is fed by an elevator to a rotary tube furnace. The mixture in the furnace is heated by the combustion products of natural gas to a temperature of 900 ^o C, heating is carried out through the wall with gas torches, while the iron is reduced by carbon carbon with the formation of sponge iron. Impurities of chromium, vanadium and manganese remain in the form of oxides. Gases containing carbon monoxide CO leaving the furnace are fed to the afterburner to the torch or to the burners of the furnace. The reduced sponge iron enters the refrigerator and, after cooling, the conveyor belt and elevator is fed to the iron dissolution reactor. Promvu is loaded into the reactor, then the calculated amount of sulfuric acid is loaded with a dosing pump. After mixing the mass, the reduced iron is loaded and mixed until it is completely dissolved, the solution is fed to a filter press to clean from insoluble suspensions. The purified solution is accumulated in the collection. Drying a solution of iron sulfate is carried out in a granulator dryer type RKSG. The granules of ferrous sulfate monohydrate are removed from the apparatus and transferred to a fluidized bed calcination furnace separated from the dryer by a sector lock. The fluidized bed in the furnace creates the products of natural gas combustion, the temperature of the product reaches 750 ^o C. The calcined granules are transferred to the lower part of the fluidized bed, from where they are discharged into the refrigeration drum, and then into the repulpator. Granules of iron oxide are repulped in promv. The coarse fraction from the hydrocyclone for re-grinding also comes here. A suspension containing granules disintegrated in water is pumped to a ball mill for grinding. The fine milled fraction is collected for subsequent processing, and the coarse milled is sent back to the milling. The pigment suspension is diluted, filtered and washed in an automatic press. The washed pigment paste is fed to a dryer with a suspended layer of an inert carrier for drying.

 Gases from the dryer and other apparatuses are dedusted in cyclones and fed to the general dust and gas cleaning system. Next, dust from all devices is collected, dissolved, dried.

 Wastewater generated during the disposal process is treated, and sulphurous gases are used to produce sulfuric acid (A. Bubnov, High technology waste scale processing with the production of red iron oxide pigment. GRNTI 83-015-2001).

 The disadvantages of this method of disposal should be noted that oil or other hydrocarbons (oil, oil products) are not separated from iron, but burned, while part of the iron is lost as a result of burning.

 The proposed technology for the utilization of oily scale in order to obtain iron oxide pigment has a very complex hardware design, and as a result of its implementation, we have to repeatedly solve the problem of treating effluents and exhaust gases, metal impurities of various metals.

 In addition, an insignificant part of the disposal problem is solved, because the demand for red iron oxide pigment is limited and the amount of processed dross will be 15,000 tons.

A known method of disposal of sheet-rolling production (a mixture of oily scale and water), providing for their heat treatment at temperatures above 80 ^o With more than 24 hours, separation of the sludge and its subsequent processing. Before heat treatment, the mixture settles for 50-150 hours, the primary sludge is removed, and the secondary (obtained after heat treatment at 80-98 ^o C for 24-50 hours) is mixed with calcium oxide in powder form at a ratio of calcium oxide to sludge mass of 1 :( 1.3-1.6), then the primary sludge is added to the mixture in an amount of 10-50% and its agglomeration is carried out. (RF patent 2078441, C 22 V 1/16. Publ. 12/27/97).

 The disadvantage of this method is the duration of the recycling process and the irretrievable loss of valuable organic raw materials.

A known method of purification of dispersed material, which can be attributed to scale, mainly from pollution by oil products, including heating the contaminated material, treating it with steam, removing water and oil products, the treatment being carried out in a medium of water vapor at a temperature of 250-600 ^o With a mass ratio : "water vapor: oil product" not less than 1/15.

 Then, the discharged mixture of water vapor and oil products is cooled to a temperature higher than the condensation temperature, while most of the condensed oil products are collected in a collection tank, and a part of the non-condensable hydrocarbon mixture is returned to the reaction zone of the steam processing unit, and the rest is sent to the furnace for combustion. (RF patent 2173223, Z. 99117474, B 09 C 1/06, Project 10.08.99, BI 21, 25-01).

 The advantage of the method is a high degree of purification, but the efficiency of such purification is doubtful, because due to the lack of chemical treatment, energy costs sharply increase, including the burning of part of valuable hydrocarbon feedstocks. The presence of exhaust gases from the furnace for burning hydrocarbons requires additional control of the composition of the gases.

A known method of processing fine scale, which is carried out in a jet of inert gas. In a steam jet, particles consisting of oil and scale pass sequentially through the stage of heating to the temperature at which the oil begins to boil, the stage of boiling until a solid skeleton is formed, and the stage of drying to the desired oil concentration. The maximum gas temperature is 400-420 ^o C, which corresponds to the beginning of thermal cracking of oils. (Sinitsyn et al. Calculation of heat transfer in a spray chamber of a separation unit for scale-oil-containing sludge from rolling mill. Iron and steel industry, 12-2000).

 Oiled scale, as a rule, has a polydisperse composition, i.e. particles of various sizes. Fine scale is formed in the water treatment system of pre-cleaned scale in the form of sludge, and for the implementation of this method, the original scale needs to be crushed on a grinder.

 The disadvantage of this method is the introduction of the grinding operation, which leads to some loss of iron, as well as the high temperature of the processing of oil-containing scale, which leads to additional energy costs.

 The closest technical solution to the proposed method is a method for cleaning oily scale, which can be used to clean oil from sand, soil, bottom sediments of oil barns and tanks (Zakharenko A. A. "Purification of the soil" index: 7099000174, base "Intellect").

 The proposed method for the complete separation of petroleum products from oil-containing scale, soil with the disposal of secondary products. In the general case, the initial sludge (a mixture of soil and oil products or oil-containing scale is crushed, loaded into a tank equipment and subjected to hydrodynamic treatment in the volume of a low concentrated heated aqueous solution of a highly effective special composition with simultaneous stirring, for example, by sparging with air and further grinding during washing at ambient temperature In the course of processing the soil or scale which is almost completely cleared of oil products It is removed from the tank and dehydrated. The average time of the cleaning and phase separation process is 5-10 minutes. The aqueous solution of the composition does not mix with liquid hydrocarbons and does not form an emulsion. After gravity sedimentation, the phases are separated: aqueous solution of TMS - liquid hydrocarbon (oil, oil, etc.). .p.) - finely dispersed scale (in the form of sludge) or clean soil - an aqueous solution of TMS - liquid hydrogen (in case of soil washing). The method allows after washing to have a clean surface, to send the scale for further processing, and clean primer prirodooborot returned in liquid hydrocarbon used for other purposes, and the solution is used repeatedly. Refined mineral materials have practically the same physical properties of the starting pure materials: appearance, natural natural color of the mineral, flowability, angle of repose. The content of residual petroleum products in mineral and plant materials after purification is not more than 0.1%.

 The disadvantages of this method include the fact that the oil-containing scale is crushed to achieve uniformity of particle size, but part of the iron is lost. When removing the washing solution and liquid hydrocarbons after phase separation, which is carried out by pumps, losses will increase, because part of the fine scale will be present in them.

 In addition, it is problematic to achieve a qualitative complete phase separation of the solid and liquid phases by gravitational sludge for 15 minutes, so the reliability of the cleaning results is doubtful.

 The technical task of the invention is the development of technology that eliminates the disadvantages of the prototype, i.e. to exclude preliminary and subsequent grinding of scale, thereby reducing iron loss, and also increase the degree of extraction of liquid hydrocarbons (oils, oil) due to the use of more efficient equipment for phase separation of wastewater after washing oil-containing scale.

 The technical result is achieved due to the fact that in the known method, including preparatory operations (unloading of oil and sludge-containing sludge from the storage place, preliminary dehydration), loading of oily scale in a washing tank, hydrodynamic washing with a heated washing solution while supplying air to the washing tank, removing the resulting oil-containing emulsions and contaminated washing solution followed by phase separation of effluents in a phase separation apparatus, oil separation, purification of detergent solution and sludge containing fine scale, their removal from the sump, followed by the use of purified washing solution in the washing cycle, and the extracted oil for its intended purpose, as well as the unloading of coarse scale from the washing tank, changes have been made.

Distinctive features of the proposed method for cleaning oily scale are the following:
- in the process of preliminary dehydration form a washout layer of polydisperse scale;
- before loading the oil-containing scale in the washing tank create a hydrodynamic regime corresponding to the speeds of the soaring of polydisperse particles along the height of the conical part of the tank, depending on their size;
- this mode is maintained by constant circulation of part of the washing solution in the washing tank with the addition of clean washing solution into it;
- phase separation of effluents into fractions is carried out in a multi-section separator;
- the scale cleaned in the washing tank and contained in the sludge discharged from the separator is dried with heated air at a temperature above the boiling point of the washing solution.

Moreover:
- as a washing solution using a 0.5-4% solution of technical detergent containing a nonionic surfactant and an active component, at a temperature of 40-55 ^o With the following ratio of components, weight. %: nonionic surfactant 2-4; active component the rest is up to 100;
- as the active component of a technical detergent, use soda ash or a composition with its partial replacement with sodium salts of phosphoric acid;
- the temperature of the washing solution in the washing tank is maintained due to the temperature of the air supplied to it during the washing of the scale, by heating it to 55-60 ^o C and intensive circulation of the washing solution;
- the washing solution for washing is supplied from the bottom up, and the heated air is higher than the conical part of the washing tank to prevent the entrainment of small particles of scale;
- when drying the scale in the washing tank itself, it is preliminarily fed with sludge discharged from the separator containing finely divided scale, at the same time the washing solution is removed and sent to the multi-section separator for cleaning;
- if not, the sludge discharged from the separator containing fine scale is filtered before drying, and the filtrate formed is sent to the inlet of the multi-section separator for re-cleaning;
- the concentration of the washing solution within the specified limits is maintained by periodically adding its components to the purified washing solution.

 In the process of preliminary dehydration of the oily scale, a filtering (wash-up) layer of polydisperse scale is formed on the grid, mainly passing only liquid. This reduces the amount of scale returned to the storage location.

 The oily scale loaded into the washing tank is not uniform in fractional composition. The size of the particles can vary from 0.3 to several millimeters, therefore it is difficult to create a regime for high-quality washing, given the fact that for each particle size the optimal regime is different, the larger the particles, the higher the washing intensity should be. One of the ways that have found widespread use (and this was noted above) is the crushing of oily scale to a finely divided homogeneous fraction. However, this leads to excessive costs and losses of iron.

 To achieve high-quality washing of polydisperse oily scale in the proposed technical solution, the optimality of the hydrodynamic regime depending on the particle size is achieved by creating a circulation circuit of the washing solution, in which approximately 60% of its volume in the washing tank is involved and the design solution is to make the lower part of the washing tank in the form of a cone . As a result of this, regardless of the size, a hydrodynamic regime is created in which the fluid velocity corresponds to the particle velocity, and the particles themselves are located along the height of the conical part in accordance with their size, i.e. there is a classification of particles by size - at the bottom the largest, and at the border of the conical and cylindrical parts - the smallest.

 The optimal hydrodynamic regime is created in the washing tank before loading oily scale into it, because creating it while loading and supplying a washing solution is very difficult, and after loading it is almost impossible.

 After loading the oily scale into the washing tank, the optimal hydrodynamic regime is maintained due to the volume of the circulating washing solution by adding the corresponding amount to the tank.

The supply of the washing solution in countercurrent with the feed material ensures intensification of washing in the area where the largest scale is located, and the supply of air heated to a temperature of 55-60 ^o С slightly higher than the conical part of the washing tank allows maintaining the optimal temperature of the washing solution - 40-55 ^o С, t. to. in the presence of a circulation circuit and the absence of heating of the washing solution, its temperature would be below the permissible level.

 In addition, given the fact that washing even the smallest scale occurs in the conical part or at the boundary of its transition into the cylindrical one, the air supplied to this zone sparges and prevents small particles of purified scale from entering the accumulation zone of the oil-containing emulsion, and therefore, its probability decreases falling into a multi-section separator.

 The implementation of phase separation of wastewater in a multi-section separator significantly reduces the time of separation of the fractions "light hydrocarbons (oil, oil) - purified washing solution - sludge" in comparison with gravity sludge and reduces the amount of equipment needed to implement the proposed method for cleaning oily scale.

 The use of a 2-4% TMS solution as a washing solution, which includes a nonionic surfactant and soda ash or a composition with a partial replacement of soda with sodium salts of phosphoric acid, eliminates the use of a special demulsifier or organic solvents and, correspondingly, stages associated with with his branch. The specific composition of the detergent used depends on the type of contamination, as When drawing or in metal production, in addition to oil, various organic solvents or hydrochloric acid salts are used, which complicates the cleaning of scale. Technical detergent (TMS), including a different combination of these components, is known under the trademark "OBIS" or "OBIS-M" and has been widely used for washing various parts, tanks, storages, etc. from hydrocarbon pollution.

 The practice of using this TMS has confirmed that, regardless of the complexity of the contamination or the shelf life of the contaminated material, the maximum concentration of the washing solution does not exceed 4 wt.%, Even a 0.5% O-BIS solution is sufficient when disposing of fresh scale with a simple contamination composition.

 When applying a concentration of less than 0.5%, there is a danger of poor-quality descaling from contaminants, and a concentration of more than 4% will significantly increase the cost of the process.

The practice of using the specified TMS with a temperature of 40-55 ^o With confirmed the correct choice of the specified range for cleaning from any oil products and other liquid hydrocarbons.

 After washing, the cleaned scale must be dried before final dehydration, so it is dried. The proposed technology offers two options for drying the cleaned scale: in the washing tank itself or outside it. The choice depends on the specific production conditions and the amount of oily scale.

 In the case of drying in the washing tank itself, the washing solution is drained from it, which is sent to a multi-section separator, and hot air is supplied from below for drying. When this option is implemented, after removing the washing solution or at the same time with it, sludge discharged from the multi-section separator and containing fine scale is loaded into the washing tank by means of a pump. Sludge is fed through an additional upper flushing tank nozzle.

 To speed up the drying process, the air supplied into the tank is heated to a temperature slightly higher than the boiling point of the washing solution, which depends on the composition of the TMS and the concentration of the washing solution. When the temperature of the coolant is lower than the boiling point, the drying time increases, and at the higher, the heat consumption increases.

 Then the dried scale is discharged onto the conveyor and fed to the packaging or directly to the smelter.

 If the cleaned scale is not dried in the washing tank, after draining the washing solution, the bottom cover of the washing tank is opened and the cleaned scale is discharged onto the conveyor and then into the storage tank. In this case, the dried scale is dried as a sufficient amount of it is accumulated. Sludge discharged from a multi-section sump can also be pumped into a storage tank, but if it is located at a sufficiently large distance from the washing tank, it is more advisable to dry the fine scale separately. It should be noted that this is also a matter of economics, as fine scale can be used not only in metallurgical, but also in other industries, for example, in the production of pigment, whitewash and as a binder; therefore, an additional classification of dehydrated scale is not necessary.

 The proposed method also provides such an option for drying fine scale. The slurry containing fine scale is discharged from the multi-section separator into a funnel-shaped container in which a pan with a filter screen is installed, the released liquid is removed, and hot air with a temperature is supplied to the pan, as in the first embodiment. After drying, finely divided scale is unloaded from the pallet and fed for further processing.

 Due to the fact that with repeated circulation of the washing solution, its concentration decreases slightly and / or its amount decreases, as a rule, after a certain number of cycles, the washing solution is adjusted by adding certain amounts of fresh water and dry TMS. In addition, sometimes it becomes necessary to change the component composition of the washing solution. This allows you to always maintain a sufficiently high efficiency of purification and yield of petroleum products.

 When developing a device that implements the proposed method for cleaning oily scale, we used information about known devices of a similar purpose, both in general and partially solving only certain stages of the cleaning process, not only identified in the analysis of scientific and technical sources related to metallurgy, but also to related industries.

A device for cleaning sandy soil from oil products (RF patent 2027825, Publ. January 27, 1995), which can be used to clean oily scale. The device includes a hopper located in the first tank, and the second tank, which are filled with hot water with a temperature of 70-90 ^o C. In the hopper there is a mixer. Contaminated soil, sand or oily scale is loaded into the hopper and washed with hot jets of water while stirring. The device is equipped with a container for separating the washing solution and liquid hydrocarbons (oil, oils, etc.). Petroleum products are collected in a collection tank, and the solution enters a second flush. Sand, soil, settled on the bottom, is unloaded and sent to the original place from where they were taken, and the scale - for further processing.

 A disadvantage of the known device is the presence of a gravity sump, because the separation time of the oily solution is quite long. Qualitative separation of phases in the sump is impossible to achieve. Only a small amount of contaminated material can be cleaned in this device.

 A device for cleaning soil and soil contaminated with petroleum products (RF patent 2108179, Publ. 04/10/1998). The device is made in a single housing, consisting of two paired parts. A separator for separating a coarse fraction in the form of an oblique spiral grid, a classifier for fractioning contaminated material in the form of a column, a washer with clean water and a particle trap for washing, located between the loading means and the washer are placed in the housing. The device is equipped with a pulse line with pulse chambers attached to the washer and the lower part of the housing, providing a hydrodynamic regime of mixing the soil, as well as batchers of contaminated soil and recycled water. The device has containers for collecting large fractions and pulp soil. After cleaning, the fine fraction is discharged through the device, and the intermediate fraction is removed from the lower part of the body and sent for repeated treatment with water.

 The disadvantages of this device include the duration of washing, because almost the larger the fraction of the material contaminated with hydrocarbons, the more washing cycles it goes through. The device does not have a separation unit for an oil or oil-containing emulsion that should have formed after washing contaminated sand, scale or soil, as well as collecting purified liquid hydrocarbons and water with their subsequent use. Based on this, we can conclude that the device cannot provide non-waste technology and is not environmentally friendly.

 A device is known (author's certificate. 802199, C 02 F 1/52, BI 5-81) containing a cylindrical hopper with nozzles for supplying the medium and air located in its upper part, and water and sediment discharge pipes in the lower part, conical part of the hopper is made of coaxial conical chambers that enter into each other, and the device is equipped with a drainage column connected to the hopper with water discharge pipes.

 The known device implements only part of the proposed method of disposal, namely the preparatory stage and loading into the washing tank.

 A device is known for purifying dispersed material from hydrocarbon contaminants (application 99117474, BI 21 (1), 2001), including working bodies for collecting, supplying contaminated and unloading purified material mounted on a common basis, a steam treatment unit for contaminated material in the reaction zone, a container for of collecting liquid petroleum products and a furnace for burning the collected liquid hydrocarbon products, equipped with a condenser cooler located between the steam processing unit and a container for collecting liquid petroleum products, moreover, Steam treatment has an additional outer heating zone connected to the outlet of the furnace, wherein the upper zone gas container is connected to the furnace reaction zone and the vapor processing node.

 A significant disadvantage of the known device is the presence of a steam treatment unit, the separation of oil after steam treatment in a sump, and then by condensation of the gas phase, but the bulk of the valuable product, which are liquid hydrocarbons, is lost during combustion.

 In addition, the device does not have a wastewater treatment unit containing oil products, which should have been formed during washing, sludge and steam treatment.

 The closest technical solution to the proposed device is a mobile unit for cleaning various materials from hydrocarbon pollution, made on the basis of a universal mobile washing station (UMPS), protected by a certificate for utility model 13333, publ. 04/10/2000

The installation is placed on the chassis of a car or other vehicle, on the frame of which means for collecting contaminated material, preliminary sorting and loading it are mounted. After preparation, the contaminated material is loaded into a washing tank, into which a washing solution with a temperature of 50-65 ^° C is supplied under pressure. The tank is equipped with nozzles for introducing a washing solution and withdrawing an oil-oil emulsion, as well as a lower hatch for unloading the solid phase after washing. Oil-and-oil-containing effluents are treated by sludge or separation into the light (oil, oil) and heavy phase (purified solution) in a tank equipped with nozzles for draining the cleaned washing solution, oil products and sludge. The purified solution is returned to the washing cycle of the contaminated material using a pressure pump, and the purified oil is decanted and transported to a collection tank or storage facility for further use. Sludge is discharged from the lower nozzles. The installation is equipped with pumps, pipelines, valves and other necessary fittings.

 The disadvantage of UMPS is that it cannot fully implement the proposed method for cleaning oily scale.

In order to implement the proposed method for cleaning oily scale in a known device, including means for unloading oily scale from a storage location, a unit for loading oily scale in a washing tank equipped with a loading funnel, nozzles for introducing a clean washing solution and outlet for an oil-containing emulsion, as well as a device for unloading washed dross, a unit for supplying air to the washing tank, an apparatus for phase separation of effluents, equipped with nozzles for introducing an oil-containing emulsion and output and he oil purified washing solution and slurry okalinosoderzhaschego connected respective conduits fitted with the locking apparatus and the respective pumps for pumping the oil and the purified washing solution, a heat exchanger for heating the cleaning solution, some changes and additions, namely:
- a tank equipped with a filter screen for preliminary dehydration of oily scale has been introduced;
- the washing tank is structurally made "pipe in pipe", and the lower part of the main pipe is made in the form of a cone to ensure a given washing mode .;
- the pipe itself is equipped with an additional nozzle connected by a pipeline to an additional circulation pump, the outlet of which is connected by a pipe to the nozzle of the input of the washing solution;
- the apparatus for phase separation of effluents is made in the form of a multi-section separator;
- a heater, an air filter and a heated air distributor are installed in series on the air supply line to supply it to the drying of cleaned scale;
- a multi-section separator is made in the form of separate sections, sequentially forming a quenching chamber of the input stream, a separation chamber made in the form of communicating two sections, with a block of coalescing plates and a chamber of purified washing solution installed in each section, and a chamber for collecting the separated oil is placed between the sections of the separation chamber ;
- in the first section of the separation chamber, in the oil separation zone, movable disks are installed on the oil separator drum equipped with a drive mounted on the lid of the multi-section separator;
- the block of coalescing plates is made of vertically arranged parallel plates;
- loading unit oily scale in the washing tank is made in the form of an endless conveyor or piston type pusher;
- the washing tank is equipped with an additional collet mounted on its lower nozzle and having an internal filter nozzle, its inlet connected by a pipe to the outlet of the heated air distributor, and the outlet to the pipeline to remove the oil-containing emulsion from the washing tank, and the lid for unloading the scale is fixed on the lower end Tsars
- the upper pipe of the washing tank is equipped with an additional nozzle connected by a pipe to an additional pump installed on the line for the discharge of sludge from a multi-section separator;
- and / or a funnel-shaped container in which a sump for sludge discharged from a multi-section separator is installed, containing fine scale, equipped with a filter screen and connected to a heated air distributor, and the outlet of this container is connected via an additional pump to the oil-containing emulsion inlet into the multi-section separator or chamber of a clean washing solution.

 The implementation of the proposed method and device for its implementation should not cause difficulties, because The main technological operations and units of the device have been tested in industrial conditions and have confirmed their operability.

 The design of the device is shown in the drawing.

 The device contains means (bucket) 1 for unloading the oily scale from the sump or sludge collector of the raw oily scale 2, a preparation tank 3 equipped with a filter net 4 and a drain 5, a loading unit 6 (conveyor or piston pusher), a loading funnel 7, which is the upper part of the washing containers 8, with pockets 9 for contaminated washing solution, a pipe 10 for introducing a washing solution, a pipe 11 for outputting an oil-containing emulsion, a pipe 12, a circulation pump 13, an input 14 of a circulating washing solution, an air heater 15, an air filter 16, valves 17 and 18 on the air supply lines, an air distributor 19, a multi-section separator 20, a flow rate damping chamber 21, a first separator chamber 22, an NLZ drive 23, NLZ 24 movable disks, an overflow partition 25, a chute 26, an oil collecting chamber 27, a protective visor 28, a purified washing solution chamber 29, a pump 30, a heat exchanger 31, a washing solution supply line 32, a valve 33, a fresh TMS supply line 34, a fresh water supply valve 35, and a drain inlet 36 to the separator , oil removal pipe 37, pipe 38 to the outlet of the clean washing solution, nozzles 39 for removing sludge from the separator, the sludge collector 40, the diaphragm pump 41, the centrifugal pump 42, the suction cup 43, the filter sleeve 44, the outlet for the outlet of the washing solution, a cover 46 for unloading scale, a funnel-shaped tank 47, a pallet 48 with a filter screen 49, a supply line 50 of washing solution to the funnel of the upper pipe, a centrifugal pump 51, a conveyor 52, a stop valve 53.

 The device is equipped with instrumentation, in particular level gauges and thermometers, which are not specifically numbered.

 Consider in more detail the implementation of the proposed method for the disposal of oily scale on the example of the device.

 Oiled scale 2, the size of which is in the range of 0.1 - 3 mm, from the place of its burial, in our case, from a sludge settler, was scooped with a bucket 1 and then unloaded into a tank 3 equipped with a filter net 4. Liquid and part of the scale along the drain 5 returns to the sump. As the formation of an alluvial layer on the grid, the amount of scale returned to the sump decreases, because the pores of the grid 3 are clogged with particles of scale 2, therefore, larger particles accumulate on the grid 3. The loading of oily scale 2 for washing was carried out with an estimated flow rate of 700 kg / h using conveyor 6 (possibly a piston type pusher). The loading of the scale in the washing tank 8 is carried out in the funnel-shaped upper pipe 7. The upper pipe has a diameter slightly smaller than the lower (main) pipe, where the washing process takes place, therefore, above its inlet form an overflow pocket 9 for the contaminated washing solution, and the end face the upper pipe is made in the form of cloves breaking the fluid flow.

Before loading the oily scale, simultaneously with the washing up of the filter layer on the screen and accumulation of scale on it, the washing solution “O-BIS” or “O-BISM” was supplied through the pipe 10 through the pipe 10 through the pipe 10, so that the volume of liquid in the washing tank was within 2.5 m ³ , the level is controlled by a level gauge. The solution was supplied from the chamber 29, having a outlet pipe 38 of the cleaned washing solution using a pump 41. In the heat exchanger 31, the washing solution was heated to 40-55 ^° C. In this example, its temperature was 48 ^° C and was controlled by a thermometer. Before loading the oily scale in the washing tank create a hydrodynamic mode, which should correspond to the speed of movement in the size range of the loaded particles. Previously, the soaring speed was determined by the nomogram given in the reference book "Thermotechnical experiment" L., "Energy", 1980, p.401, and was calculated to determine the washing speed. The maximum flow rate of the solution in the washing zone was 0.3 m / s (minimum 0.09 m / s), while the lower diameter of the cone is 0.34 m, and the cylindrical part is 1 m, the height of the cone is 1.65 m. This hydrodynamic The mode was created by creating a circulation circuit, including a pipeline with shut-off valves and connected to the nozzle 12 and the circulation pump 13. The circulating washing liquid is introduced into the washing tank through the nozzle 14. After reaching the maximum specified flow rate, a grease was charged second scale in a washing tank. The loaded oily scale is distributed along the height of the cone according to the size of the particles in accordance with the speed of their soiling that large particles of scale are floating at the top of the cone, where the speed corresponds to the minimum, are the smallest particles. This hydrodynamic mode was maintained by the volume of the circulating solution, and the flow rate of the solution added to the washing tank was regulated by a valve on the supply line of the clean washing solution.

Heated air was supplied to the boundary zone of the cylindrical and conical parts of the washing tank, which was heated to a temperature of 55 ^° C in heater 15, the heating temperature was measured with a contact thermometer, which, when the set temperature is reached, turns off the heating device. The air is dried in the filter 16 and through the valve 18 and the pipeline enters the washing tank. The valve 17 at this time is in the closed position. The air supply inside the washing tank pursues several goals: to promote the intensification of the allocation of a lighter fraction in the upper part of the tank and at the same time prevent the finely dispersed scale from getting into this layer; maintaining the temperature of the washing solution in a predetermined range of 40-55 ^o C.

 In this example, the washing of the scale is carried out with a 1.0% detergent solution of a technical tool, consisting of the following components - 3.0 wt. % nonionic surfactant (nonionic surfactant), representing an ethoxylated polyoxypropylene glycol derivative of ethyldiamine (Alcatronic EDP) and 97 wt.% soda ash. The washing time is 5-8 minutes.

 During the washing process, the top layer, rich in oil, forms an emulsion and, together with the contaminated washing solution that has got into the overflow pocket 9 through the pipe 12, enters through a pipeline equipped with shut-off valves, enters a multi-section separator 20, where the oil-containing emulsion is phase separated into oil, purified washing solution and sludge containing fine scale.

 It happens as follows. The oil-containing emulsion from below through the nozzle 36 enters the quench chamber 21. In this chamber, the flow rate is quenched, and it enters the first chamber of the two-section separator 22, in which a thin-layer module is installed, made of separate vertical parallel-located coalescing plates that form gap channels between them . The upper edges of the plates protruding above the partition wall of the section form a comb, playing the role of a uniform flow distributor over individual slotted channels. As a result of the fact that the flow enters the upper part of the first section of the separator 22 and exits in the opposite diagonal angle, in this section, as in the quenching chamber, a condensation zone is formed in which sludge accumulates. When the oil-containing stream passes through the slotted channels, the natural process of coalescence occurs, i.e., oil droplets become larger and due to the difference in density of the washing solution and oil, they accumulate in its upper part, and the main stream of contaminated washing solution enters the second section of the separator 22, in which a thin-layer module similar to that installed in the first section is also installed.

 Coalescing plates capture small droplets of oil, while the droplets adhering to the surface of the plates merge and coarsen, forming a continuous film, which rises up to the same zone under the action of the Poiseuille effect. Since the outer wall of the first section is made somewhat lower than the walls of the separator body, an unloading threshold 25 is formed as a result of which the oil flows into the accumulator 27. However, the main part of the oil enters the chamber 27 using an oil separator (NLF) installed in the first section of the separator 22. The NLV is equipped with a drive 23 mounted on the housing cover of the multi-section separator, and its movable disks 24, mounted on the drum, were immersed in the oil accumulation zone . The rotation of the drum is carried out from the drive 23 due to the connection of its shaft with the shaft of the oil separator by a belt or chain transmission. The drum rotates in such a direction that the oncoming film of oil is attacked by the descending half of the movable disks 24. Under these conditions, the bulk of the oil is pressed against the movable disks, wetting their surface, and forms a well-held film on it. This film is removed from their surface by scrapers and by gravity flows through the trough 26 into the chamber 27 of the accumulation of oil products.

 The washing solution, freed mainly from oil, exits the bottom of the inlet of the second section from the outlet of the first separator section. In the slotted channels of the block of coalescing plates installed in this section, more dense solid particles are separated from the washing solution. This is because, due to the parabolic distribution of velocities in the slotted channels, the upward flow forces the denser particles toward the plates forming the walls of the slotted channels (Poiseuille effect). Forcing solid particles to the surfaces of the coalescing plates, the flow carries them out due to the diagonal direction of motion into the stagnant zone. The location of stagnant zones where sludge accumulation can be judged by the location of the nozzles 39, through which the sludge is removed from the separator 20. The clarified water through the second discharge threshold with a visor 28, configured to change its height relative to the common partition of the second separator section and the chamber 29 where the purified detergent solution accumulates and, as necessary, is supplied, as already described above, into the washing tank. To maintain the temperature of the washing solution in the chamber 29, part of the solution heated in the heat exchanger 31 is directed into it, opening the valve 33.

 The oil collected in the chamber 27 through the pipe 37 through the diaphragm pump 41 was sent for recycling.

 Sludge containing fine scale from the multi-section separator 20 was sent to the collector 40 and then pump 42 into the washing tank 8.

The phase separation time in a multi-section separator takes several minutes, therefore, in parallel with it, after washing, the washing solution was removed from the washing tank. To do this, a valve and a solution were opened on the drain line of the washing solution, through a collet 43, inside which a ceramic filter 44 was inserted, and the nozzle 45 was sent to a multi-section separator. At the same time, the valve 18 was closed, and the air supply to the washing chamber from above was stopped. After draining the washing solution, valve 17 was opened and the air heated in the heater 15 to a temperature of 105 ^° C (the boiling point of the washing solution 98 ^° C) passed through the dispenser 19 to the washing tank 8 from below, passing a ceramic filter 44. This filter prevents fine particles from entering into the scales in the removed washing solution, which makes it possible to pour it directly into the chamber 29 to replenish the total volume of the washing solution, and also performs fine cleaning of the air entering the dryer. Drying time 3 min. After drying, open the lid 46, located at the end of the drawer 43, and completely dehydrated scale is unloaded onto the conveyor 52 and then for specific use.

 On this, the operation of the device is completed, and then the next cycle of cleaning the next portion of the oily scale occurs in the same sequence.

 In the process of further work, after a given number of cycles of use of the washing solution, or in the case of an increase in its concentration, or changes in the composition, the washing solution is corrected by adding fresh water (opening valve 35) and / or dry technical detergent (line 34). Correction is carried out directly in the tank 29.

 The proposed technology provides for various options for drying the cleaned scale and sludge containing fine scale. One of the possible options is described in the above example. It is possible to dry the scale outside the washing tank by unloading it into the storage tank, and then through the distributor 19 to send hot air to this tank.

 Sometimes, for industrial or other reasons, it is more expedient to wash the washed scale and sludge containing finely divided scale separately. The design of the device provides for the implementation of such an opportunity. In this case, the valve on the sludge supply line to the washing tank is closed, and the sludge from the collector 40 is discharged into a pan 48 installed in a funnel-shaped tank 47, and the pan is equipped with a filter net 49. The filtrate formed is pumped 51 to the inlet of the multi-section separator 20 by means of a pipeline with on it with shutoff valves. Hot air is supplied to the pallet 48 from the distributor 19, and the fine scale is dried.

The advantages of the proposed method for cleaning oily scale and device implements it are:
- Creation of environmentally friendly and non-waste cleaning technology;
- elimination of the stage of crushing of scale, thereby reducing iron loss;
- achieving optimal washing conditions regardless of the size of the particles of the scale;
- saving energy and detergents;
- the versatility of the device, because it can be used to clean not only scale, but also soil, soil, sand, without making significant changes to the design.

 Currently, several devices have been designed that implement the proposed technology for a number of interested organizations, and they are undergoing pilot-industrial operation, and during 2002 a wide industrial application of the technology is expected.

Claims (17)

1. A method of cleaning oily scale, including unloading it from the storage location, pre-dewatering, loading the oily scale in a washing tank, hydrodynamic washing with a heated washing solution while supplying air to the washing tank, unloading coarse scale and removing the resulting oil-containing emulsion and contaminated washing solution washing tank with subsequent phase separation of wastewater in a phase separation apparatus with the release of oil from them, purified washing solution and sludge containing fine scale, removing them from the phase separation apparatus with the subsequent use of the purified washing solution in the washing cycle, and the oil as intended, characterized in that during the preliminary dehydration, an wash layer of polydisperse scale is formed, and before loading the oil-containing scale in the washing tank create a hydrodynamic regime corresponding to the speeds of the soaring of polydisperse particles along the height of the conical part of the washing tank, depending on their size, and under keep this mode by constantly circulating part of the washing solution in the washing tank with the addition of clean washing solution into it, the phase separation of the effluents is carried out in a phase separation apparatus made in the form of a multi-section separator, and coarse fine scale cleaned in the washing tank and the sludge removed from the multi-section separator containing fine scale, subjected to drying with heated air. 2. The method according to claim 1, characterized in that a 0.5-4.0% solution of a technical detergent containing a nonionic surfactant and an active component is used as a washing solution at a temperature of 40-55 ° C, in the following ratio components, wt.%: nonionic surfactant 2-4, active component - the rest is up to 100. 3. The method according to claim 2, characterized in that as the active component of the technical detergent use soda ash or a composition with a partial replacement of it with sodium salts of phosphoric acid. 4. The method according to any one of claims 1 to 3, characterized in that the temperature of the washing solution in the washing tank is maintained due to the temperature of the air supplied to it during the washing of the scale by heating it to 55-60 ° C and intensive circulation of the washing solution. 5. The method according to any one of claims 1 to 4, characterized in that the washing solution for washing is supplied from the bottom up, and the air is higher than the conical part of the lower pipe of the washing vessel to prevent entrainment of small particles of scale. 6. The method according to any one of claims 1 to 5, characterized in that the drying of coarse scale, cleaned in a washing tank, and sludge containing fine scale, is carried out with air having a temperature above the boiling point of the washing solution. 7. The method according to any one of claims 1 to 6, characterized in that the coarse scale is dried in the washing tank itself, while sludge containing fine scale, unloaded from the multi-section separator, is fed into it, the washing solution is removed from it and sent to cleaning in a multi-section separator. 8. The method according to any one of claims 1 to 6, characterized in that the sludge containing fine scale discharged from the multi-section separator is dehydrated by filtration before drying, and the dehydrated fine scale is dried, and the filtrate is sent for re-treatment. 9. The method according to any one of claims 1 to 8, characterized in that the concentration of the washing solution within the specified limits is maintained by periodically adding its components to the purified washing solution. 10. A device for cleaning oily scale, containing means for unloading the oily scale from the storage location, a unit for loading oily scale in a washing tank having a loading funnel, nozzles for introducing a clean washing solution and the outlet of drains of an oil-containing emulsion and contaminated washing solution, as well as a device for unloading washed coarse scale, a unit for supplying air to the washing tank, a device for phase separation of effluents with nozzles for introducing an oil-containing emulsion and contaminated m cleaning solution and the output of oil, purified washing solution and scale-containing sludge, connected by appropriate pipelines with shutoff valves installed on them and corresponding pumps for pumping oil and purified washing solution, as well as a heat exchanger for heating the washing solution, characterized in that it is equipped with an additional a tank containing a filter screen for preliminary dehydration of oily scale, the washing tank is structurally made "pipe in pipe" and consists of a top pipes and the main pipe, and the lower part of the main pipe is made in the form of a cone, and the pipe itself is equipped with an additional pipe connected by a pipe to the circulation pump, the outlet of which is connected by a pipe to the pipe for the input of the washing solution, the apparatus for phase separation of wastewater is made in the form of a multi-section separator, and a heater, an air filter and a heated air distributor are installed in series on the air supply line to supply it to the drying of cleaned scale. 11. The device according to claim 10, characterized in that the multi-section separator is made in the form of separate sections, sequentially forming a quenching chamber of the input stream, a separation chamber made in the form of two communicating sections with a block of coalescing plates installed in each section, and a chamber of a purified washing solution and between the sections of the separation chamber there is a collection chamber for the extracted oil. 12. The device according to claim 11, characterized in that the first section of the separation chamber has an oil separation zone equipped with an oil separator drum with movable disks mounted on it, equipped with a drive mounted on the lid of the multi-section separator. 13. The device according to claim 11 or 12, characterized in that the block of coalescing plates is made of vertically arranged parallel plates. 14. The device according to any one of paragraphs.10-13, characterized in that the site for loading oily scale in the washing tank is made in the form of an endless conveyor or piston type pusher. 15. The device according to any one of paragraphs.10-14, characterized in that the washing tank is equipped with a collet mounted on its lower nozzle and having an internal filter nozzle, and its inlet is connected by a pipe to the outlet of the heated air distributor, and the outlet is connected to the oil-containing removal nozzle emulsions from the washing tank, and at the end of the drawer there is a lid for unloading the scale. 16. The device according to any one of paragraphs.10-15, characterized in that the upper pipe of the washing tank has an additional nozzle connected by a pipeline to a pump installed on the line for discharging sludge from a multi-section separator. 17. The device according to any one of paragraphs.10-15, characterized in that it is equipped with a funnel-shaped tank in which a sump for collecting sludge containing fine scale, discharged from a multi-section separator, equipped with a filter screen and connected to a heated air distributor is installed, and the outlet the specified capacity is connected by means of an additional pump to the pipeline for introducing an oil-containing emulsion into a multi-section separator or by a chamber of a purified washing solution.