RU2212925C2 - Method and plant for recovery of solid sediment from fluid substance by evaporation - Google Patents

Abstract

FIELD: dehydration of various substances, particularly, liquid manure. SUBSTANCE: method includes application of treated substance in form of thin layer to smooth and hot side 10 of heat exchange wall 1 made for motion over closed cyclic trajectory. Substance layer is flattened on this side for layer leveling and spreading, and at the end of cycle, solid and dry sediment is removed. In so doing, directly before application, treated substance is subjected to considerable volume expansion for giving foam consistency to it and applied to hot side 10 in form of thin layer. EFFECT: higher efficiency of claimed method and plant. 26 cl, 23 dwg

Description

 The invention relates to a method and apparatus for recovering by evaporation of a solid precipitate contained in the form of a suspension and / or solution in a fluid substance containing volatile substances, in particular in an aqueous substance.

 It was previously proposed to apply a thin layer of the substance to be processed on the smooth and hot side of the heat-exchange wall, which is heated to the temperature necessary for the rapid evaporation of water and / or other volatile substances contained in this substance, while the hot wall is made to move along a closed cyclic path , then flatten the layer of the substance on the hot side of the wall to level it and ensure its grinding and spreading, and, finally, to collect by scraping at the end of the cycle a solid docking formed on said hot side wall.

 A similar method is described in WO 93/16005, which is incorporated herein by reference.

 The installation described in this publication contains a series of horizontal coaxial and parallel disks mounted on one rotating shaft, with each of the disks forming a movable wall, and its upper side forming the hot side on which the substance is processed.

 In this known solution, the application of the substance to the rotating disk is carried out using an oscillating rocker, on which is installed a pipe for supplying the substance connected to the upper side of the disk. The breaking of the material layer is carried out in the described implementation method by means of a series of drum flattening means.

 The binding at the end of the cycle is carried out using a scraper connected to a small brush, which is preferably mounted on an oscillating beam, which ensures the application of the substance; a scraper and a brush are used to remove outward dry sediment.

 In the method and installation described in document WO 93/16005, the disks and the shaft supporting them are hollow, their internal spaces communicating with each other, forming a chamber called condensation, and a set of disks is installed inside a chamber called evaporative, and the installation is equipped with system for removing steam generated in the evaporation chamber, for mechanical compression of this steam and for supplying compressed steam to the condensation chamber, while non-condensable components are removed from the steam before re-compression by physic nomic processing.

 Thanks to this design, the amount of heat that is released during the condensation of steam inside the disks is transferred to the substance through the heat exchange wall on the upper side of the disk and contributes to the evaporation of the equivalent volume of liquid in the layer of the processed substance deposited on this upper side.

 Thus, the heat released during condensation is removed for evaporation, ensuring operation at a low energy consumption, approximately corresponding to the consumption of mechanical energy necessary for vapor compression.

This method and installation for implementing the method are adapted, in particular, for the treatment of slurry, in particular slurry obtained from a pig farm; however, the installation operates at a pressure of about 0.1 MPa and at a temperature of about 100 ^° C in an evaporation chamber and at a pressure of about 0.14 MPa and at a temperature of about 110 ^° C in a condensation chamber.

 Although the present invention is intended for use in an installation that uses the heat generated by condensation on one side of a heat exchange wall to provide evaporation on the other side of this wall, its scope is not limited to this.

 Indeed, it can be applied on heated evaporation surfaces where the principle of mechanical compression of steam is not used; in this case, it requires much more material costs for such a method than for a method in which repeated mechanical compression of steam is used; in addition, it can be used to treat certain substances and / or in other cases where energy consumption does not pose insoluble problems.

 Regardless of whether the treatment is carried out using a normally heated dehydration surface (for example, using the Joule effect) or according to the principle of vapor re-compression, it is very important that the dehydrated substance be applied in the form of a very thin and very uniform layer on a smooth and clean surface.

 However, the experiments conducted by the applicant showed that the solution to this problem, at first glance very simple, is extremely difficult to achieve when processing certain substances, such as animal feces, dirt from sewage treatment plants and many wastes of agricultural enterprises.

 Such wastes have much in common. They contain a lot of water (about 85-98%), are relatively fluid, heterogeneous in composition and sediment. The chemical composition of their steam is very complex. They act very aggressively on materials in general, and also create big problems associated with clogging and clogging of pipelines, valves and pumps of the installation.

 In an optimal embodiment, the thickness of the layer of the substance deposited on the heating surface should not exceed 1 mm and preferably should be about 0.5 mm.

 However, the physical nature of the dehydrated substances makes it impossible to use conventional devices such as nozzles, perforated ramps, distribution slots or capillary application. It is almost impossible to apply the substance in the form of a liquid layer of such an insignificant thickness.

 An object of the present invention is to solve this problem.

 To this end, the method in accordance with the invention includes the previously mentioned steps and is characterized in that immediately before applying the substance to the hot side of the heat exchange wall, the substance is significantly expanded in volume, giving it a foam consistency with the possibility of applying this foam to the hot side in the form of a thin layer. In a preferred embodiment, the applied layer has a thickness of less than 1 mm and preferably of the order of 0.5 mm.

 Such volumetric expansion is preferably carried out at a degree of expansion from 20 to 100.

 In accordance with a further possible distinguishing feature, which is preferred, unwanted particles remaining on the hot side after the scrubbing operation are removed to prevent them from entering the foam application zone.

 Indeed, the presence of sediment in the foam formation zone can lead to clogging of the expansion device and interfere with foaming.

 This method can be used for the treatment of slurry, in particular slurry from pigs.

 The extraction apparatus according to the present invention is a conventional apparatus and is characterized in that the means for supplying and applying the substance are capable of providing a significant volume expansion of this substance to give it a foam consistency and to apply this foam to the hot side in the form of a thin layer.

In addition, in accordance with a number of additional distinctive features of the installation, not limiting it:
- the hot side is made flat and horizontal, and the means of volume expansion of the substance contain a casing mounted above this hot surface, open from below and from the side, in the direction of movement of the movable wall, as well as means for supplying the processed substance to the casing, while the casing limits the expansion chamber of the substance, the bottom of which is formed by a hot moving surface;
- the substance is fed into the housing using a volumetric pump through an auger formed by a brush mounted rotatably in the supply pipe;
- the housing contains a bottom with a bottom made flat, horizontal and parallel to the hot side, while the bottom is movable in the vertical direction with the possibility of lowering and pressing (periodic) to the hot side to clean it;
- the installation contains means for instantly stopping the pump and lowering the bottom of the housing for cyclic pressing it to the hot side, while the lifting of this bottom after this occurs automatically using elastic return means;
- the housing in vertical projection has an expanding profile, the open side of which is directed towards the movement of the movable wall, while the supply of matter is carried out at the entrance of the housing in its narrow zone;
- the flattening means comprise at least one flexible sheet pressed against the substance by means of elastic means, such as a leaf spring;
- the flexible sheet performs a reciprocating oscillatory motion with a weak amplitude;
- such a sheet is made of polytetrafluoroethylene;
- the scraper means comprise a set of scrapers working in cascade and cycling in an essentially elliptical trajectory;
- the heat exchange wall is made in the form of a rotating disk with a vertical axis of rotation, the upper side of which forms a hot surface, and the scrapers are made with the possibility of gradual movement of sediment outside the disk and its removal in a vertical collector;
- the installation contains an additional scraper, made with the possibility of scraping the edges of the disk;
- it contains a fixed shield in the form of an arc of a circle mounted on the edge of the disk directly behind the means of applying the substance to the disk and preventing the foam from escaping outward;
- it contains means for mechanically removing particles remaining on the hot side, while these means are located behind the scrubbing and removal means and in front of the application means;
- means for removing particles contain a metal sheet for collection connected to at least one outlet screw;
- means for removing particles made with the possibility of removing the latter from the disk outward;
- the installation contains many identical horizontal disks mounted coaxially at a certain distance from each other, rotating in the form of a block around a vertical axis, while the installation further comprises a heated annular collection track, made at the base of the installation in line with the edge of the disks;
- it contains many scrapers, rotating synchronously with many disks inside the collection track and made with the possibility of moving the particles located on it to the outlet hole located at the base of the collector;
- it contains scrapers made with the possibility of scraping off the sediment adhering to the lower side of the discs and dropping it onto the upper side of the adjacent adjacent disc and / or onto the collection track;
- the disks are hollow and mounted on a tubular shaft, the inner space of which communicates with the inner space of each disk, while these spaces form a chamber called condensation, and many disks are installed inside the chamber, called the evaporative one, and the installation contains a system for removing steam, obtained in the evaporation chamber for mechanical compression of this vapor and for supplying compressed steam to the condensation chamber;
- the installation comprises a device for the extraction and compaction of sediment, made in the form of a pair of heating belt conveyors;
- the installation contains means for flushing with hot water on the hot side.

 Other features and advantages of the present invention will be more apparent upon consideration of the following description and the accompanying drawings, in which non-limiting embodiment is shown.

 The device is illustrated by the following drawings.

 FIG. 1 is a simplified diagram of an embodiment of a method in accordance with the invention.

 Figa - element in Fig.1, which shows the bottom of the foaming casing in the lower position for cleaning the hot side.

 Figure 2 is a schematic front view of the lower part of the installation for extraction, containing many hollow disks.

 Figure 3 is a schematic illustration of a disk, a top view.

 Figure 4 - image of the power supply pump installation.

 FIG. 4A is an image of a camshaft element for controlling a pump.

 FIG. 5 is a schematic representation of a foaming casing for expanding a substance, top view.

 FIG. 6 is a cross-sectional view along a vertical plane indicated by VI-VI in FIG. 5.

 FIG. 7 is a schematic partial image of a disk showing flattening means made in the form of a flexible sheet.

 Fig. 8 is a side view of the same means.

 FIG. 9 is a partial image of the disk, a top view showing the design of the means of scaling and their effect.

 FIG. 10 is a partial schematic illustration of an elliptical motion control system for scrapers.

 11 and 12 are a schematic illustration of a scraper, respectively, a top view and a front view.

 FIG. 13 is a schematic cross-sectional view of a possible embodiment of mechanical particle removal means.

 FIG. 14 is a partial image of a disk, a top view showing at the same time means for scrapping, means for removing small residual particles and means for supplying a substance and foaming.

 Fig. 15 is a schematic sectional view of the lower portion of the installation at the base of the collector and at the inlet of the device for extracting and compacting sediment.

 FIG. 15A is an image, side view, of one of the scrapers moving along the collection track directly at the entrance of the outlet.

 Fig is a General top view of the lower disk and the removal system.

 FIG. 17 is a sectional view of a device for extracting and compacting sludge.

 Fig. 18 is a fragment of Fig. 17 depicting a driving drum of a conveyor belt.

 FIG. 19 is a partial view, top view, of a removal and sealing device.

 Fig - image, top view of the flap on the edge of the disk.

 FIG. 21 is a cross-sectional view along the vertical plane XXI-XXI shown in FIG.

 With reference to FIG. 1, a general principle for implementing the method in accordance with the present invention is presented.

 The processed substance is, for example, slurry from pigs.

 The dehydration of the substance is carried out on the heat exchange wall 1, which is heated to the temperature necessary for the rapid evaporation of water and / or other volatile components contained in the processed substance.

 The upper side 10 of this wall is smooth and flat.

 Wall 1 is movable. She moves from left to right in figure 1, and the direction of its movement is indicated by the arrow R.

 Preferably, this movement should occur at a constant speed.

 As will be shown below, if the surface 10 is the upper side of the disk, then the movement R is rotational at a constant and slow speed.

 Therefore, we are talking about cyclical movement, while applying the substance to the hot side 10 is carried out at the beginning of the cycle, and the removal of various types of sediment is carried out at the end of the cycle, while side 10 comes to the place of application of the processed substance is already completely cleaned.

 As will be shown below, this place 2 is made in the form of a casing, the bottom of which is designated 20. The casing is open simultaneously from below and from the side, in this case, toward the direction of movement R.

 The substance is fed into this casing by means of means that comprise a screw 21 mounted rotatably in the pipe. The cross section of the pipe for supplying the substance is made smaller with respect to the volume of the inner space of the casing 2. As a result, partial evaporation and rapid expansion of the substance occurs, which is converted into an emulsion and takes on the consistency of the foam.

 Depending on the nature of the substance, the foam may be more or less dense. The shape and dimensions of the casing provide a degree of expansion from 20 to 100. This means that the volume of the foamy substance formed in the casing is 20-100 times larger than the volume of the substance when it is fed using the screw 21.

 Due to the gradual evaporation of this emulsion, shown by arrows E in FIG. 1, an increasingly dry and thinner layer is obtained.

 This layer reaches the flattening means 3 intended for grinding and spreading the substance layer on the hot side, thereby obtaining a uniform layer by leveling the small irregularities formed in it, as a result of which the quality of heat exchange between the hot side and the substance is significantly improved.

 Flattening means will be described below with reference to FIGS. 7 and 8.

 At the end of dehydration, the layer consists of a dry or substantially dry precipitate. At this stage, scraper means 4 come into action, which scrape off sediment r and remove it from surface 10 into the collector.

 Means of bracing will be described below with reference to figures 9 and 10.

 Despite this operation, small particles of p still remain on the hot side 10.

 Indeed, some types of sediment are not susceptible to scraping agents, in particular due to its adhesion to the hot side. Other particles p were scraped off by means of scraping, but were separated from them during movement.

 It is necessary to remove these unwanted particles p so that they do not get into the foaming casing, as this will quickly lead to its clogging and interfere with the expansion process.

 To do this, between means of bracing 4 and the casing 2 is made means 5 for removing particles p from the hot side 1.

 These means are described below with reference to FIGS. 13 and 14.

 As shown in FIG. 1, it is possible to periodically clean side 10 by lowering the bottom of the casing 20 and pressing it under a certain force to side 10. With this action, the structure of the resulting agglomerate consisting of heavy sludge or partially dried substance adhering to side 10 is destroyed.

 In FIG. 2 schematically and partially shows a rotary disc dehydration unit similar to that described in WO 93/16005.

 This installation contains a tank 6 with isothermal walls 60 of a cylindrical shape with a vertical axis ZZ ', mounted on a support 61, mounted on the ground.

 Inside the tank 6, a series of hollow disks 1 are made, which are located and mounted on the same tubular shaft 100 with the axis ZZ '.

 This structure is held in rotation by a guide device 101 mounted on the bottom of the tank 62.

 The internal space of the tubular shaft 100 and the hollow discs form a condensation chamber, and the space external to the discs inside the reservoir forms an evaporation chamber.

 The steam obtained in the evaporation chamber is subjected to mechanical compression by means not shown in the figure, and fed into the condensation chamber, as shown in the figure by arrow a.

 The resulting condensate enters the drive 63, made in the base of the tubular shaft 100, and is periodically removed from it, as shown by arrow b.

 For information, the design can contain from 20 to 30 disks with a diameter of about 2 m.

 The hollow shaft 100 is continuously rotated by appropriate means (not shown in the figure) with a constant uniform and relatively low speed, for example, about 0.33 revolutions per minute.

 In FIG. 2 also shows an annular track 7 fixed to the bottom 62 inside the tank. This track is made in the form of an annular U-shaped channel, the open side of which is directed upwards and is at the level of the edge of a row of disks.

 It is understood that substances removed outside the discs fall under the influence of gravity into track 7.

 A lot of scrapers 71 are made inside the track 7. They are located at a certain angular distance from each other and are mounted on an additional disk 72, which also rotates around the axis ZZ '.

 In a preferred embodiment, this lower disk 72 is integral with the tubular shaft and rotates simultaneously with the disks.

 On the left in FIG. 2 shows an electric gear motor 48 with an end shaft 47.

 As will be shown below, this rotating shaft provides a reciprocating oscillatory movement of a pair of rockers 44, 44 ', on which the means of bracing are made.

 A general top view of FIG. 3 allows you to consider the location of various points on each disk 1, the rotation direction of which is shown by arrow R.

 This figure shows a pump 213 for feeding the substance to the screw 21, a foaming casing 2, flattening means 3, scraper means 4 and residual unwanted particles removing means 5. The figure also shows an annular track 7 along which a plurality of scrapers 71 move, as well as a small brush 710 designed to clean the bottom of each of these scrapers.

 Figure 3 also shows the vertical collector 8 and the shield 12, the functions of which will be discussed below.

Figure 4 shows a device for feeding the processed substance having a temperature close to the dehydration temperature, for slurry this temperature is approximately 100 ^o C.

 In a preferred embodiment, the slurry is preheated with the distillate obtained during evaporation while passing through a heat exchanger in which the slurry and distillate move in opposite directions.

 A heat exchanger for such preheating is described in patent application 99 00655 of January 14, 1999, which is incorporated herein by reference.

 The substance is supplied using a volumetric pump 213, the characteristics of which, in particular the flow rate, are selected depending on the area of drainage and the nature of the substance; if we are talking about slurry, you can use a centrifugal pump with a flow rate of about 25 to 50 l / h.

 The screw 21 is designed to supply substance to the casing 2 and contains a pipe 218, inside of which a helicoidal brush 217 rotates, forming the screw itself; this design is used to avoid clogging and clogging of the pipe.

 The pump 213 is powered by a substance supply line 210 through a three-channel shutter 212. The device further comprises a hot water supply 211, and by manipulating the shutter 212, either the substance to be processed or hot water can be supplied to the pump (for the cleaning step).

 The pump 213 is driven in rotation from the gear 216, which in turn is rotated through the clutch by a motor not shown in the figure. The clutch comprises a drive cam assembly, on which a helicoidal compression spring 215 acts.

 The pump can be disconnected from the drive gear 216 when the cam shaft 200 is rotated, and shutdown occurs when the cam shaft cam 201 pushes the rod 217 integral with the drive cam assembly. This allows for a cyclic cessation of the supply of the substance into the casing 2.

 As shown in FIG. 4A, the shaft 200 comprises several cams 201 displaced relative to each other in the angular direction and uniformly distributed along the longitudinal direction of the shaft. Each disk is connected to a separate pump, which is switched off using one of the cams. The angular displacement allows you to separate in time the cleaning cycles from one disk to another, to ensure uniformity of the overall process of dehydration in the installation.

 The screw 21 enters the casing 2, which is shown in detail in FIGS. 5 and 6.

 The casing 2 contains a frame 22, which in vertical projection has an expanding shape. It is made in the form of a vertical partition in contact with the hot side 10 through the gasket 23.

 The casing contains a horizontal plate 20, called the "bottom" (since the casing is upside down, its opening is directed downward) and located at a certain distance from side 10, while the entire assembly is made of insulating material.

 The lower side 2000 of the bottom is made flat and smooth and parallel to side 10.

 This bottom 20 is held in the upper position by means of springs made of elastic wire or elastic plates 25, which pull it up and press it against the stops 24; the latter are made in the form of semicircular plates uniformly distributed and fixed on the upper part of the frame 22.

 A flexible membrane 26, one of the edges of which is fixed on the upper part of the frame 22, and the other on the adjacent lower edge of the side of the bottom 2, provides tightness at this level.

 In the image above, the frame 22 has a symmetrical shape of an approximately V-shaped form with branches diverging in the direction of movement R. The branches of V are slightly rounded, with their convex side facing the inside of the casing.

 The feed screw 21 is connected to a narrow zone 29 corresponding to the top V.

 A relatively dense substance injected by the screw 21 into the area 29 of the casing falls into the beginning of the expanding space bounded above by the bottom 20, on the sides diverging partitions 22 and below by the movable hot side 10, on the other hand, this space is open in the direction of movement R.

 As shown in FIG. 3, the mouth of this V-shaped casing is located substantially radially over the entire surface of the disk from the central shaft 100 and to the edge of the disk.

 As a result of partial flash evaporation under the action of heat from the hot side 10, an increase in volume and a decrease in pressure, the substance M turns into an emulsion with the formation of bubbles and takes on the consistency of a foam.

 This foam is spread over the entire radius of the moving disk.

 On the upper part of the plate forming the bottom 20, a pair of pads 28 is fixed.

 These pads act as opposite stops, with which on each revolution the cams 280 come into contact, fixed on the lower side of the adjacent adjacent disc, which abut against the pads 28 and force the bottom 20 to move downward (arrow P), pressing it to the surface 10.

 After passing the cam 280, the elastic plates 25 cause the plate 20 to automatically rise up and push against the blocks 24, and at the same time take its normal position.

 Turning off the pump by cams 201 is synchronized with the lowering of the bottom of the casing 20 with the possibility of stopping the flow of the substance for a certain period of time, during which the plate 20 rubs on the surface 10.

 Thus, the disk is cleaned at each revolution, that is, every three minutes, while the cleaning takes several seconds.

 In addition to such often repeated cleaning, it is possible to provide additional cleaning with hot water, for example, every 3-6 hours, replacing the substance to be dried with hot water, or selectively disk by disk using a three-channel shutter 212, or all disks simultaneously. Such additional purification with hot water is preferably carried out in 1-2 revolutions, that is, over a period of 3 to 6 minutes.

 Separate cleaning of each disk slightly affects the normal overall installation process.

 Such cleaning is performed additionally at each start-up and shutdown of the installation.

 Cleaning with hot water is necessary to remove contaminants that inevitably occur during the passage of substances that are particularly difficult to process and form after several hours of operation a deposition in the form of a film, which is very thin, but nevertheless sufficient to significantly reduce the dehydration efficiency.

 At the exit of the casing 2, the foamy substance should not fall on the edges of the disk.

 For this, a shield is made directly at the exit from the casing 2.

 In FIG. 20 and 21, it is shown that the shield 13 consists of a pair of arched strips concentric with the disk and compressing the flexible tape 12. The latter is pressed against the edge of the disk and acts as a sealing apron that prevents the substance from flowing outside the disk. The shield is mounted on a finger 140, mounted on one end of the elastic plate 14, the other end of which is fixed on a fixed part. The elastic plate 14 presses the gasket 12 against the upper side of the disk with a certain force. The apron 12 is made of flexible synthetic material that is resistant to aggressive substances.

 The shield is located on a limited sector of the circle, since after applying the substance and the beginning of its dehydration, the need for it disappears.

 With reference to Figs. 7 and 8, a description will now be made of a preferred embodiment of the flattening means 3.

 These means comprise a V-shaped profile 30 fixed at one end of the elastic plate 34 having a relatively high degree of rigidity; the plate 34 is located approximately in the middle of the radius of the disk and is oriented in the general direction of movement of the disk in this area. It can bend horizontally. The other end of the plate 34 is fixed to the bracket 33, made integral with the fixed part 400. The latter serves as a guide, with the possibility of free travel with angular deviation, for the translational movement of the rocker arm 40, which is part of the means of bracing 4, which will be described below. Rocker 40, shown in FIG. 7 by a dashed line, oscillates with a small amplitude d and is centered at part 400.

 The V-shaped profile 30, the apex of which is directed upward, contains one vertical wing, and its other wing is inclined downward to the exit (in the direction of movement of the R disk).

 Under the sloping wing, a strip 31 of an elastic sheet made of stainless steel is fixed, partially overlapping a wide sheet 32 of PTFE (polytetrafluoroethylene).

 This sheet is pressed against the upper side of the disc under effort.

 The steel strip 31 and the sheet 32 are in the shape of a rectangle, the larger side of which corresponds to the length of the profile 30 on which they are fixed.

 This large side 32 forms an acute angle α with respect to the radial direction. This angle is the entry angle with respect to the central zone of the disk, which causes the substance to move to the center of the disk, and not to its periphery, otherwise a part of the substance could leak out of the disk.

 At the end of the profile 30, directed inside the disk, a cam 35 is fixed, in normal position in contact with the oscillating beam 40.

 Oscillation is transmitted through this cam 35 to the flexible sheet 32, which also performs a reciprocating motion. The amplitude of this movement is about 10-30 mm. The return of the sheet 32 is due to the elasticity of the plate 34.

 During movement, a wide sheet of PTFE flattenes funnel-shaped depressions and other irregularities of the substance, makes them flatter and provides a thin and uniform layer across the entire width of the disk, which contributes to good heat transfer and efficient drying.

 With reference to FIGS. 9-12, a description will now be made of the design and operation of the bracing means.

 These tools contain many scrapers, in this example in the amount of four, designated 41a, 41b, 41c, 41d. The scrapers are separated from each other by uniform intervals and are located along a line close to the radial direction, with the first scraper 41a located in the central zone (near the hub 100), and the last scraper 41d located in the peripheral zone of the disk.

 Each scraper is made at the end of the leaf spring 43 mounted on the beam 40.

 The beam is made in the form of a horizontal angular lever, the free end of which extends beyond the central part of the disk and is guided with translational movement with the possibility of slight angular deviation using part 400.

 The shoulder of the opposite end 44 is extended by a connecting rod 45, which is driven by an eccentric gear 46b.

 The eccentric gear is engaged with a drive gear 46a mounted on the drive shaft 47.

 The latter is driven with constant and uniform speed by the engine 48, mentioned above with reference to figure 2.

 Each scraper is pressed against the upper side 10 of the disk with its leaf spring 43.

 The force of the leaf spring is transmitted to the scraper through the ball 430, welded to the bottom of the spring.

 In the above example (Fig. 11, 12), the scraper 41 is provided with two side scraper plates 42.

 Preferably, these plates are made of very hard metal with a good coefficient of friction, for example, tungsten carbide.

 The position of the scraper with respect to the leaf spring 43 can be adjusted using the connecting pin 431, for example with a thread (only its axis is shown in Fig. 12).

 Due to this design, in which the ball 430 acts as a ball joint, the scraper plates can be optimally pressed against the surface of the disc, even if there are plane defects on it.

 As shown in FIG. 9, various scrapers are located on a line forming an angle with respect to the strictly radial direction of the disc.

 The outer scraper 41d is closer to the periphery of the disc than the previous scraper 41c, and so on to the inner scraper 41a.

 Due to the movement created by the crank-crank system 41b / 45, each scraper moves along a closed oval path, approximately elliptical, shown in FIG. 9 by a thin line. The various trajectories ta, tb, tc, td overlap each other in a scale-like manner, so that the scrapers work in a cascade.

 Thus, the sediment scraped off by the first scraper 41a along its entire trajectory moves to the next scraper 41b; the latter moves to the next scraper 41c the scraped off sediment and the sediment moved by the first scraper, and so on until the last scraper 41d.

 The latter pushes the sediment outside the disk into a vertical semi-cylindrical collector 8, made on the edge of the disk opposite the scraper 41d.

 Each disk is connected to such a set of scrapers, the last of which are located opposite the collector 8.

 All sediment taken from various disks is discharged into the collector 8 and falls to its bottom under gravity.

 As shown in FIG. 10, the same gear 46b drives two rocker arms, namely the rocker arm 44, and the rocker arm 44 ′ of the disk located above.

 Two connecting rods corresponding to the rocker arms 44 and 44 'are pivotally connected at diametrically opposite points on the drive gear 46b with the possibility of proper balancing of forces at the level of the hubs of gears 46a, 46b.

 The same design is made for the entire set of disks, that is, one drive mechanism is connected to a pair of bracket units.

 Figure 9 shows that on the beam 40, 44 installed elements 441, also in the amount of four.

 They are made upward directed scrapers, which may have the same configuration as the scrapers already described.

 They are located a little closer to the center than the scrapers 41.

 They are designed to scrape the lower part of the disks located above them, on which a deposition of the substance also forms due to the significant amount of foam leaving the casing at the beginning of the cycle, while the copious foam may come into contact with the lower part of the disks.

 The sediment scraped off by these scrapers 441 falls onto the disk and combines with the sediment discharged by the scrapers 41 into the collector 8.

 It should be noted that at the inlet of the manifold 8 a scraper plate 80 is made, pressed against a cylindrical rib or edge of the disk.

 This sediment is removed by the plate 80 and falls under gravity into the underlying track 7.

 It should be noted that the deposits formed on the lower part and on the edges of the disks have a chemical composition different from the sediment of the base substance; the bubbles leading to the formation of these deposits do not contain sludge; on the contrary, they contain soluble substances, in particular chloride compounds of sodium and potassium.

 As deposits accumulate, their drying becomes impossible; they remain under the discs and on their ribs in a wet state, which can lead to rapid corrosion damage of stainless steel.

 Secondary cleaning using scrapers 441 and 80 allows you to keep the layers of chloride compounds in a dry form with a very small thickness, therefore, harmless in terms of corrosion.

 At the exit of the means of scrubbing 4, not all of the sediment is completely removed. Small particles of sediment remain on the disk, having a more or less high degree of adhesion, some of them falling from the scrapers. These particles must be removed and discarded in the collection track 7.

 Otherwise, the back of the foaming casing will be completely dirty after a few hours of operation.

 To solve this problem, the machine is equipped with means for removing these particles, shown in Fig.13 and 14.

 These means 5 comprise a thin, hard, and resilient metal sheet 50.

 It is an elongated metal sheet, transversely bent approximately in the form of U, the open part of which is directed towards the beginning of movement and which is located essentially parallel to the line of scrapers 41 immediately after this line.

 The lower branch 500 of the U-shaped sheet is tightly pressed to the side 10 and acts as a knife collecting particles as they appear.

 The sheet 50 also acts as a casing in which a screw 51 is mounted, driven by an end gear 53 engaged with a corresponding pinion gear, not shown in the figure. The ends of the screw are installed in the guide parts that form the thrust bearings, made integral with the casing 2 (adjacent).

 The screw is made of stainless steel and has very smooth screw walls; the direction of its rotation allows you to move particles outside the discs, clipped with a knife 500 and held in the casing 50.

 In a preferred embodiment, two screws 51 and 51 ′ are used that fit into each other, as shown in FIG. 13.

 Particles moved by this device are removed outside the disk and also fall under the action of gravity into the annular track 7.

 As shown in Fig. 15, the collector 8 is connected at its base to a circular hole 81 made in the bottom wall of this track.

 Under this opening 81, a device 9 is installed for extracting and compacting all the sediment removed from the discs using the various means described above.

 In FIG. 15A is a side view of one of the scrapers 71 constantly rotating in track 7.

 It is made in the form of an elastic plate, for example, of spring steel, the upper part of which is made integral with the mounting part 710, mounted under the drive disk 72.

 The plate 71 is inclined downward and toward the beginning of movement, and its free lower end is bent at right angles with the possibility of scraping various particles p located on the track and moving them to the hole 81 through which they enter the input of the extraction device 9.

 Due to the fact that the scrapers 71 periodically pass through the collector 8, they are contaminated by the sediment falling into this collector, which results in the presence of a small cleaning brush 710, described above with reference to FIG.

 The extraction and sealing device 9 comprises a pair of belt conveyors 90, 91.

 They are horizontal conveyor belts. The lower belt conveyor 90 is longer than the belt conveyor 91, and part of its branch, not blocked by the conveyor 91, passes under the hole 81.

 Belt conveyors 90, 91 are made in the form of metal belts, driven at the output by driving drums, respectively 900, 910; driven drums are installed at the entrance and are designated 901, 911, respectively, the direction of their rotation is respectively indicated by arrows m and n.

 These tapes rub on intermediate heating plates 95 and 96, respectively, capable of withstanding high pressure loads, with the possibility of compaction and extraction of the collected precipitate and its additional drying.

 Traction forces applied to each belt may exceed 1000 daN. Therefore, metal tapes contain links, and the drums 900 and 910 on the periphery are equipped with teeth 913, made with the possibility of engagement with these links.

 On the driving drums 910, 900, end gears 931 are installed (see Figs. 18 and 19), which mesh with each other to ensure synchronization and the same speed of movement of both belt conveyors; conveyors are driven by a geared motor 94, on the output shaft 93 of which a drive gear is mounted, connected to the driving drums using a transmission chain 930.

 Both belt conveyors can be parallel to each other, as shown in the figures, or slightly converge to seal the sediment at the outlet.

 After compaction, the precipitate comes out in the form of a pie through an adjustable die 950, called a knife die.

 The conveyor device is installed in the container 97; the tightness of the knife die in relation to the container is provided by gaskets 951.

 The tightness of the dehydration tank with respect to the evaporation chamber is ensured by the dried sludge itself, since it is sufficiently compacted in the die to provide this necessary tightness.

 It should be noted that the diameter of the drums 910, 900, 911, 901, the distance between two belt conveyors, their angle of inclination, their width and speed depend on the nature and flow rate of the processed substance.

The extraction device is designed to move the precipitate falling through the hole 81, to seal it and remove it outside the installation, while ensuring vapor impermeability, since the evaporation chamber, inside which the temperature reaches about 102 ^o C, is under increased pressure relative to atmospheric pressure ; for information, the value of this increased pressure may range from 50 to 100 Pa.

 The method and installation described above can be used for the treatment of slurry, in particular obtained from pig farms.

 In addition, they can be adapted for other applications, for the treatment of various substances, for example, the mud of treatment plants and the waste of agricultural enterprises.

Claims (26)

 1. The method of extraction by evaporation of a solid precipitate contained in the form of a suspension and / or solution in a fluid containing volatile components, and in particular in an aqueous substance, comprising the following steps: a) the substance to be treated (M) is applied in a thin layer on the smooth and hot side (10) of the heat exchange wall (1), heated to the temperature necessary for the rapid evaporation of water and / or other volatile components contained in the substance, while the hot wall (1) is made with the possibility of movement in a closed cycle personal trajectory, b) the substance layer (M) is flattened on the hot side (10) to level it and ensure its grinding and spreading, c) at the end of the cycle, solid and dry sediment (2) formed on the hot side is removed by scraping, characterized in that immediately before applying the substance it is subjected to significant volume expansion to give it a foam consistency and then this foam is applied in the form of a thin layer on the hot side.  2. The method according to p. 1, characterized in that the volume expansion is performed to a degree of from 20 to 100.  3. The method according to p. 1 or 2, characterized in that the particles (p) remaining on the hot side after the scraping operation are removed to prevent them from entering the foam application zone.  4. The method according to one of paragraphs. 1-3, characterized in that the processed substance (M) is slurry, in particular slurry from pigs.  5. Installation for the extraction of solid sediment contained in the form of a suspension and / or solution in a fluid substance containing volatile components, and in particular in an aqueous substance containing a) a heat exchange wall (1) with a smooth and hot side (10), heated to the temperature necessary for the rapid evaporation of water and / or other volatile components contained in the substance, the wall being able to move along a closed cyclic path, b) means (21, 2) for supplying and applying the processed substance to the hot nku in the form of a thin layer, c) means of flattening (3), made with the possibility of crushing and spreading the layer of substance on the hot wall (10), d) means (4) of scaling and removal of solid precipitate formed at the end of the cycle (r), characterized the fact that the means of supply and application (21.2) are intended to provide a significant volume expansion of the substance (M) and to give it the consistency of the foam immediately before its application and for applying this foam to the hot side (10) in the form of a thin layer.  6. Installation according to claim 5, characterized in that the hot side (10) is flat and horizontal, and the installation includes means for volumetric expansion of the substance, comprising a casing (2) mounted above the hot wall, open simultaneously from below and from the side in the direction of movement movable wall, and means (21) for supplying the processed substance to the casing, while the casing limits the expansion chamber of the substance, the bottom of which is formed by the hot moving side (10).  7. Installation according to claim 6, characterized in that the substance (M) is fed into the casing (2) by means of a volume pump (213) through a screw made in the form of a brush (217) mounted for rotation in the supply pipe (218) .  8. Installation according to claim 6 or 7, characterized in that the casing (2) contains a bottom (20), the lower side (2000) of which is made flat and horizontal and is parallel to the hot side (10), while this bottom made vertically movable with the possibility of lowering and pressing against the hot side (10) to clean it.  9. Installation according to paragraphs. 7 and 8, characterized in that it contains means (200, 201, 216, 214, 215; 28, 280) for simultaneously stopping the pump (213) and lowering the bottom (20) of the casing to press it against the hot side in a cyclic manner, in this case, the raising of the bottom (20) is then carried out automatically using elastic return means (25).  10. Installation according to one of paragraphs. 6-9, characterized in that the casing (2) has a vertical projection of an expanding profile, the open side (O) of which is directed towards the movement (R) of the movable wall (1), and the substance is supplied at the entrance of the casing into its narrow zone (29 )  11. Installation according to one of paragraphs. 5-10, characterized in that the means of flattening (3) contain at least one flexible sheet (32) pressed against the substance (M) by means of elastic means, such as a leaf spring (3).  12. Installation according to claim 11, characterized in that the flexible sheet (32) performs an oscillatory reciprocating motion (d) of low amplitude.  13. Installation according to claim 11 or 12, characterized in that the flexible sheet (32) is made of polytetrafluoroethylene. 14. Installation according to one of paragraphs. 5-13, characterized in that the means of bracing (4) contain a set of scrapers (41a, 41b, 41c, 41d) that work in cascade and make a cyclic movement of an essentially elliptical trajectory (t _a , t _b , t _c , t _d ).  15. Installation according to one of paragraphs. 5-14, characterized in that the heat exchange wall (1) is a rotating disk with a vertical axis (ZZ '), the upper side (10) of which forms the hot side, and the scrapers (41) are made with the possibility of gradual movement of the sediment (r) outside disk and dropping them into a vertical collector (8).  16. Installation according to p. 15, characterized in that it contains an additional scraper (80) made with the possibility of scraping the ribs (11) of the disk.  17. Installation according to claim 15, characterized in that it contains a fixed shield (12) of an arcuate shape located on the edge of the disk (1) immediately behind the means (2) for applying the substance (M) to the disk (1) and preventing the foam from escaping outward.  18. Installation according to claim 5 or 6, characterized in that it contains means (5) for mechanical removal of particles remaining on the hot side (10), while these means are located behind the means (4) of scrubbing and removal and in front of the means (2) application.  19. Installation according to p. 18, characterized in that the means (5) for removing particles contain a metal sheet (50) for collection, connected to at least one outlet screw (51).  20. Installation according to p. 15 or 18, characterized in that the means (5) for removing particles are made with the possibility of their removal outside the disk (1).  21. Installation according to p. 15, characterized in that it contains many identical horizontal disks (1) located coaxially and at a certain distance from each other, rotating in a block around a vertical axis (XX '), and an annular heated collection track (7 ) performed at the base of the installation in line with the edge of the discs (1).  22. Installation according to claim 21, characterized in that it comprises a plurality of scrapers (71) rotating synchronously with a plurality of disks inside the collection track (7) and configured to move the particles contained therein to the outlet hole (81) made at the base of the collector (8).  23. Installation according to p. 21 or 22, characterized in that it contains scrapers (440, 441), made with the possibility of scraping deposits adhering to the inner side (1 ') of the disks, and dropping them on the upper side (10) of the next lower disk (1) and / or to the collection track (7).  24. Installation according to one of paragraphs. 21-23, characterized in that all the disks (1) are hollow and mounted on a tubular shaft (100), the inner space of which communicates with the internal space of each disk (1), while these spaces form a condensation chamber, many disks are installed inside the evaporative chamber (6), moreover, the installation comprises a system for the removal of steam produced in the evaporation chamber, for mechanical compression of this steam and for supplying compressed steam to the condensation chamber (6).  25. Installation according to one of paragraphs. 5-24, characterized in that it contains a device (9) for extracting and compacting the entire sediment, made in the form of a pair of heating belt conveyors (90, 91).  26. Installation according to one of paragraphs. 5-25, characterized in that it contains means (211, 212, 213) for cleaning with hot water on the hot side (10).

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