EA037175B1 - Skimmer for a lamellar thickener - Google Patents

Abstract

The claimed invention is intended for removal of foam forming during various flotation processes, and can be used, in particular, for clarification of a suspension when producing potassic fertilizers. The claimed invention is intended for work jointly with thickeners, in particular, with thickeners equipped with sets of inclined lamels. The proposed skimmer for a lamellar thickener comprises a rectangular frame (1) of the skimmer fixed on the top of thickener lamels set frame, one of transverse sides of said rectangular frame carrying a drive (2) with a drive shaft (3), and a number of traction elements (4) located in parallel in longitudinal direction at a set pitch; each of them is linked to the drive shaft (3) via a corresponding drive support (5) installed on said shaft, and equipped with a tensioning device (6) mounted on the transverse side of the frame (1) of the skimmer, opposite to the drive (2). Each traction element (4) is endless and closed on the corresponding drive support (5) of the drive shaft (3) and the support (7) of the corresponding tensioning device (6), and equipped with a number of working scrapers (8) distributed at a set pitch along the whole length of said traction element (4). The frame (1) is equipped at least with one cleaning scraper (11) made and located with a capability of cleaning the working scrapers (8).

Description

(54) FOAM EXTRACTOR FOR PLATE THICKENER (43) 2020.08.31 (96) 2019 / ЕА / 0017 (BY) 2019.02.28 (71) (73) Applicant and patentee:

IGNATOVICH ARTEM

MIKHAILOVICH (BY) (72) Inventor:

Ignatovich Mikhail Ivanovich,

Ignatovich Artyom Mikhailovich (BY) (74) Representative:

Belyaeva E.N., Belyaev S.B., Sapega

L.L. (BY)

RU-U1-139641

SU-A-342672

RU-U1-176210

CN-Y-201245483

037175 B1

037175 Bl (57) The invention is intended to remove foam formed in various flotation processes, and can be used, in particular, in the process of clarifying the suspension in the production of potash fertilizers. The claimed invention is intended to work in conjunction with thickeners, in particular with thickeners equipped with packs of inclined plates. A foam remover for a plate thickener is proposed, containing a rectangular frame (1) of a foam remover fixed on top of the frame of a package of thickener plates, on one of the transverse sides of which a drive (2) with a drive shaft (3) is installed, and a set of traction elements located in parallel in the longitudinal direction with a given pitch (4), each of which is connected to the drive shaft (3) by means of a corresponding drive support (5) mounted on the specified shaft and equipped with a tensioning means (6) mounted on the transverse side of the skimmer frame (1) opposite to the drive (2). Each traction element (4) is made infinite and is closed on the corresponding drive support (5) of the drive shaft (3) and the support (7) of the corresponding tensioning means (6) and is equipped with a plurality of working scrapers (8) distributed with a predetermined step along the entire length of the specified traction body (4). At least one cleaning scraper (11) is installed on the frame (1), made and located with the possibility of cleaning the working scrapers (8).

The claimed invention is intended to remove foam formed in various flotation processes, and can be used, in particular, in the process of clarifying the suspension in the production of potash fertilizers. The claimed invention is intended to work in conjunction with thickeners, in particular with thickeners equipped with packs of inclined plates.

Thickeners are used in various technological processes of the mining, in particular potash, and chemical industries, as well as in water treatment systems. Thickeners of various designs have found wide application in the potash industry for thickening sludge and salt products to obtain a clarified mother liquor. For thickeners operating on flotation slurries, various systems are provided for removing foam with foam removers into a foam receiver with its subsequent withdrawal from the process. At the same time, despite the importance of foam control, the prior art rarely discloses in detail the designs of foam removers and / or defoamers. For example, it is known that in the Supaflo thickener, foam is removed using foam bumpers, swivel spars and a collection box. The foam is collected in a box and removed from the thickener [1].

One of the types of thickeners used, in particular, in the potash industry for thickening sludge production wastes, are plate thickeners, among which one can mention Metso's highly efficient thickeners, which are manufactured using the Lamella technology [2]. Metso thickeners, based on Lamella (plate deposition) technology, provide high efficiency in classifying material or components, reducing reagent consumption and significantly reducing the size of the apparatus compared to standard thickeners. Constructions of this type of thickener are known to those skilled in the art, but at the same time, the issues of collecting the foam formed in the upper layer and removing it from the technological process for this type of thickener are not covered in detail in the prior art.

In general, as part of various flotation devices, often designed for water purification with removal from its surface, formed in the process of cleaning foam, skimmers are known, in the design of which there are scrapers / blades moving along a certain trajectory. Thus, a device is known for removing the foam product from the chambers of a flotation machine [4], in which the blades move along a circular path around the shaft axis. This design of the foam removal device is not very effective, because the removal of foam is carried out locally, and not over the entire surface area.

There is also known a foam remover as part of a flotation machine, installed in the upper part of the bath [5]. However, its design has not been considered in detail - only a graphically depicted shaft mounted on bearing supports and equipped with blades, the width of which corresponds to the width of the bath, and there is only an indication that the foam remover ensures smooth removal of the foam product from the entire surface of the bath mirror.

Also known is a foam scraper as part of a flotation water purification system, which contains a scraper, which, by means of a drive mechanism, moves along the surface in the flotation tank. The scraper extends across the flotation tank, preferably from side wall to side wall with little or no clearance [6]. The drive mechanism can be chain driven, worm gear, or any other suitable mechanism. The material from which the scraper is made and other design features of the scraper are not disclosed.

Most of the skimmers mentioned above are known for use in flotation devices for water treatment. The possibility of their use in flotation devices, in particular thickeners, from the composition of technological equipment in technological processes of mining, in particular potash, and chemical industries is not mentioned.

According to the results of the analysis of the prior art, the prototype for the inventive foam remover for the plate thickener was not selected by the applicant.

Thus, the object of the invention is to develop a design of a foam skimmer for a plate thickener, which can be used in technological processes, primarily in the mining, in particular potash, industry. The skimmer should be simple in design, allowing easy installation on the thickener and easy maintenance. The foam remover should also have a lower weight and metal content compared to known designs.

The problem is solved by the inventive foam remover for a plate thickener, containing a rectangular foam remover frame fixed on top of the frame of the plate pack of the thickener, on one of the transverse sides of which a drive with a drive shaft is installed, and a set of traction elements located in parallel in the longitudinal direction with a given pitch, each of which is connected to by a drive shaft by means of a corresponding drive support installed on the specified shaft and equipped with a tensioning means installed on the transverse side of the foam remover frame opposite to the drive. In this case, each traction element is made infinite and is closed on the corresponding drive support of the drive shaft and the support of the corresponding tensioning means and is equipped with a plurality of working scrapers distributed with a predetermined step along the entire length of the specified traction

- 1 037175 organ. In addition, at least one cleaning scraper is installed on the frame, made and located with the possibility of cleaning the working scrapers.

In principle, as already mentioned above, in the prior art, foam removers are known in the form of a scraper, which is moved over the surface of the contents of the thickener by means of drive mechanisms with a pulling member in the form of, in particular, a chain. However, the design of the inventive foam remover provides a plurality of parallel traction elements connected to a common drive shaft, each of which provides a plurality of working scrapers distributed with a predetermined pitch along the entire length of the traction element. This design ensures that the entire surface area is covered, i. E. simultaneous collection of foam practically over the entire surface. This reduces the load on the individual scrapers and increases the foam removal efficiency. The presence of many identical pulling elements with scrapers does not complicate the design of the foam scraper as a whole and provides a high degree of unification.

In preferred forms of implementation of the inventive foam remover, at least one traction element contains a plurality of intermediate supports located in the longitudinal direction with a predetermined pitch, each of which is mounted on an axis associated with the longitudinal sides of the rectangular frame, and the corresponding intermediate supports of all traction elements are installed on the same axis ... This design of the foam remover practically eliminates the sagging of the traction elements and maintains the linear movement of all scrapers of all traction elements above the surface.

In various forms of implementation of the inventive foam remover, the traction element can also have various forms of execution, but the preferred forms of implementation are in which the traction element is formed by hinged links, each of which is made of a polymer material, preferably thermoplastic polyurethane. Thermoplastic polyurethane is a polymer material that combines the hardness of tough plastic and the elasticity of natural rubber. In this case, one of the features of the material is the ability at the initial stage of obtaining a substance to set and adjust the necessary parameters in accordance with the target area of use. So in the case when the basis of thermoplastic polyurethane is polyesters, it additionally increases the tensile strength, wear resistance and it becomes possible to quickly restore its original shape. Specialists in this field of technology know, in particular, the use of thermoplastic polyurethane for the production of conveyor belts [7] and even for the production of snow chains [8]. Thus, the properties of the currently available polymeric materials make it possible to use them for the production of traction elements, in particular, traction elements of the chain type, consisting of separate hinged links, in various conveyor-type systems.

Within the framework of the further description, the traction body, which is a set of separate articulated links, will be referred to as a chain-type working body for the sake of shortening the description.

Taking into account the low weight, as well as the elasticity of the traction elements, no additional requirements are imposed on the supports for them. So preferred from this point of view are the simplest forms of implementation, in which the drive support is made in the form of a drive sprocket with a bearing, the support of the tensioning means is made in the form of a tension sprocket with a bearing, and the intermediate support is made in the form of a roller.

In also preferred forms of implementation of the inventive foam remover, the working scraper and the cleaning scraper are made of a polymer material, preferably polyurethane. The execution of the main working bodies (traction bodies, working and cleaning scraper), which are in constant contact with a chemically aggressive medium (foam), from polymeric materials will exclude their damage due to corrosion, which increases their durability. At the same time, the insignificant loads that the working bodies perceive (including due to the distribution of many working scrapers over the entire area, i.e., in fact, reducing the load on one scraper), do not lead to the need for their frequent replacement due to their damage, for example, attrition of workers scrapers or rupture of a chain-type working body.

Preferred are also the forms of implementation of the inventive foam remover, in which the drive shaft is made up of a plurality of separate shafts, sequentially interconnected by drive couplings, and the number of these shafts corresponds to the number of traction elements. In such forms of implementation, in fact, a modular structure of the working bodies is provided, in which the foam remover, depending on the width of the frame of the foam remover (frame of the plate pack), can be completed with the corresponding number of separate modules of the working bodies.

The aforementioned and other advantages and advantages of the inventive foam remover for a plate thickener will be discussed further on the example of one of the possible preferred, but not limiting forms of implementation with reference to the positions of the figures of the drawings, which schematically show:

fig. 1 is a general view of the inventive foam remover for a plate thickener;

fig. 2 - side view of the foam remover;

fig. 3 - top view of the foam remover;

- 2 037175 fig. 4 - view of the foam remover from the side of the drive shaft.

FIG. 1-4 in various forms, schematically, for example, one of the possible preferred forms of implementation of the inventive foam remover for a plate thickener is presented.

The foam remover contains a rectangular frame 1 of the foam remover, fixed on top of the frame of the package of thickener plates (not shown in the drawings), on one of the transverse sides of which a drive 2 with a drive shaft 3 is installed. with a predetermined pitch of the traction elements 4. Each of the traction elements 4 is formed by pivotally connected links, each of which is made of a polymer material, in particular thermoplastic polyurethane, and is connected to the drive shaft 3 by means of a corresponding drive support 5 installed on the specified shaft 3, in the presented form of implementation made in the form of a drive sprocket with a bearing. Each traction body 4 is equipped with a tensioning means 6 installed on the opposite drive 2 of the transverse side of the frame 1 of the foam remover. The traction element 4 is made endless and is closed on the corresponding drive support 5 of the drive shaft 3 and the support 7 of the corresponding tensioning means 6, in the presented form of implementation made in the form of a tensioning sprocket with a bearing. Each traction element 4 is equipped with a plurality of working scrapers 8, distributed with a predetermined pitch along the entire length of the specified traction element 4. The defoamer in the presented form of implementation for each working element 4 contains a plurality of intermediate supports 9 located in the longitudinal direction with a predetermined pitch. Each intermediate support 9 is mounted on an axis 10 associated with the longitudinal sides of the rectangular frame 1. The corresponding intermediate supports 9 of all parallel traction elements 4 are mounted on the same axis 10. In the presented embodiment, the intermediate supports 9 are made in the form of a roller.

On the frame 1 of the foam remover, a plurality (in the presented form of implementation - three, according to the number of traction elements) of cleaning scrapers 11, made and located with the possibility of cleaning working scrapers 8. Cleaning scrapers 11, as well as working scrapers 8, are made of polymer material, is installed, preferably polyurethane.

In the embodiment shown in FIG. 1-4, the drive shaft 3 is made up of a plurality of separate shafts 12, sequentially interconnected by drive couplings 13, and the number of individual shafts 12 corresponds to the number of traction elements 4 - in the presented implementation form, three.

The claimed foam remover for the plate thickener works as follows.

The dimensions (length and width) of the rectangular frame 1 of the foam remover are selected in accordance with the dimensions of the frame of the thickener plate package. On one of the transverse sides of the frame 1 of the foam remover, a drive shaft 3 with a drive 2 is installed, and on the opposite transverse side - tensioning means 6 with supports 7 of tensioning means made in the form of tensioning sprockets with bearings. On the drive shaft 3 (including one consisting of separate shafts 12, interconnected by drive couplings 13), drive supports 5 are placed, which are drive sprockets with bearings. In the longitudinal direction between the longitudinal sides of the frame 1 of the foam remover with a predetermined pitch, axes 10 are installed, on which intermediate supports 9 are located in the form of rollers. The number of intermediate supports 9 and the pitch of their installation on the axis 10 corresponds to the number of traction elements 4 and the pitch of their installation on the frame 1 of the foam remover. Thus, the corresponding intermediate supports 9 of all traction elements 4 are installed on the same axis 10. Each traction element 4, made in the form of an endless working element of the chain type made of heat-resistant polyurethane, is closed on the corresponding drive support 5 of the drive shaft 3 and the support 7 of the corresponding tensioning means 6 and equipped with a plurality of working scrapers 8 made of polyurethane, distributed with a predetermined pitch along the entire length of an endless working body such as a chain. On the frame 1 of the foam remover from the side of the drive shaft 3, cleaning scrapers 11 made of polyurethane are installed.

The skimmer (frame 1) is mounted directly on the top of the frame of the inclined plate pack. By means of the tensioning means 6, the working bodies 4 (working bodies of the type of a chain made of thermoplastic polyurethane) are tensioned until their sagging is eliminated. They include drive 2, which drives drive shaft 3 (or separate shafts 12 connected by drive couplings 13) and drive supports 5 installed on it. Since the foam remover provides a common drive 2 and a common drive shaft 3 (or separate shafts 12 connected by couplings 13 drive), the rotation of all drive sprockets of all drive supports 5 is synchronized. The rotation of the drive sprockets of the drive supports 5 moves in the longitudinal direction the traction elements 4 of the chain type with the working scrapers 8 installed on them. The working scrapers 8, in the process of moving the working traction elements of the 4 type of the chain, capture the foam formed on the surface of the liquid on the corresponding section of the surface area and transport foam into a chute intended for this (not shown in the drawings) for subsequent removal outside the thickener vat (not shown in the drawings). Due to the presence of axles 10 with intermediate supports 9 installed on them in the form of rollers, regardless of the length of the frame 1 of the foam remover, it is possible to avoid sagging of the pulling elements of the 4 type of chain and thereby maintain their constant linear position above the liquid surface, which increases the efficiency of foam removal. Due to the presence of a plurality of working scrapers 8, distributed over the area of the scraper, and, consequently, over the surface area of the liquid, the collection of foam at each moment of time is carried out practically over the entire area, which also increases the efficiency of the process and at the same time reduces the load on each working scraper 8.

When the working scrapers 8 pass the installation zone of the cleaning / s scraper / s 11, the working scrapers 8 are automatically cleaned from foam residues, etc. adhesion, which also increases the efficiency of the process, by eliminating the braking of the traction elements of the 4 type of chain when moving in the return branch of the contaminated working scrapers 8, and also by eliminating the need for technological stops to clean the working scrapers 8.

The design of the claimed foam remover is quite simple and at the same time versatile and can be used for plate thickeners of any manufacturer. Taking into account the above-mentioned modularity, a constructively simple increase in the width of the skimmer is possible. It is also possible to manufacture a device for removing foam with two and three lines of foam removal (each of which is made in the form of the inventive foam remover) for each individual package of plates. It is also possible to manufacture the foam remover of the declared design of various lengths without the risk of sagging of the traction element.

Sources of information:

1. Thickening in a thin layer. Electronic resource "Studopedia" - [Electronic resource] - January 14, 2019 - Access mode: https: //studopedia.ru/3_6543 9_sgushcheniev-tonkom-sloe.html

2. Metso plate thickeners are the fastest way to reduce operating costs in the thickening stage. A.V. Fechtman, magazine "Mining Industry", No. 2 for 2009, - [Electronic resource] - January 14, 2019 - Access mode: https://mining-media.ru/ru/article/anonsy/668-plastinchatye-sgustitelimetso- kratchajshij-put-k-sokrashcheniyu-ekspluatatsionnykh-zatrat-na-stadii-sgushcheniya

3. 5.2.1. Flotation with the release of air from the solution. Basics of wastewater treatment and solid waste processing. L.O. Stripping, F.P. Turenko. Textbook Omsk: Publishing house of OmSTU, 2005. - [Electronic resource] - February 7, 2019 - Access mode: http://ekolog.org/books/23/2_5_2.htm

4.A.S. USSR No. 337150, publ. 06/07/1972.

5.A.S. USSR No. 810289, publ. 04/09/1981.

6. Application US No. 20130112626 A1, publ. 05/09/2013.

7. Polyurethane tape. Rusconbelt LLC website. - [Electronic resource]

- January 14, 2019 - Access mode: https: //www.ammeraal-rus.ru/produktsiya/konveyernye-lenty/sinteticheskie-konveiemie-lenti/

8. BASF has developed a plastic for snow chains. Internet resource colesa.ru. [Electronic resource] - January 14, 2019 - Access mode: http://colesa.ru/news/49609.

Claims (6)

1. Foam remover for a plate thickener, containing a rectangular frame (1) of the foam remover fixed on top of the frame of the plate pack of the thickener, on one of the transverse sides of which there is a drive (2) with a drive shaft (3), and a plurality of traction bodies (4), each of which is connected to the drive shaft (3) by means of a corresponding drive support (5) installed on the specified shaft and equipped with a tension means (6) installed on the opposite drive (2) transverse side of the frame (1) of the foam remover, and each traction element (4) is made infinite and is closed on the corresponding drive support (5) of the drive shaft (3) and the support (7) of the corresponding tensioning means (6) and is equipped with a plurality of working scrapers (8) distributed with a predetermined step along the entire length of the specified of the traction body (4), while at least one cleaning scraper (11) is installed on the frame (1), made and located with the possibility of cleaning the barrel scrapers (8). 2. Foam remover according to claim 1, characterized in that for at least one traction element (4) contains a plurality of intermediate supports (9) located in the longitudinal direction with a predetermined pitch, each of which is mounted on an axis (10) associated with longitudinal sides of the rectangular frame (1), and the corresponding intermediate supports (9) of all traction elements (4) are installed on the same axis (10). 3. Foam remover according to claim 1, characterized in that the traction element (4) is formed by pivotally connected links, each of which is made of a polymer material, preferably a thermoplastic polyurethane. 4. Foam remover according to claim 3, characterized in that the drive support (5) is made in the form of a drive sprocket with a bearing, the support (7) of the tensioning means (6) is made in the form of a tensioning sprocket with a bearing, and the intermediate support (9) is made in the form of a video. - 4 037175 5. Foam remover according to any one of claims 1 to 4, characterized in that the working scraper (8) and the cleaning scraper (11) are made of a polymer material, preferably polyurethane. 6. Foam remover according to claim 1, characterized in that the drive shaft (3) is made up of a plurality of separate shafts (12), sequentially interconnected by drive couplings (13), and the number of said shafts (12) corresponds to the number of traction elements (4 ).