EP2910315B1

EP2910315B1 - Self-cleaning tank

Info

Publication number: EP2910315B1
Application number: EP15000249.1A
Authority: EP
Inventors: Josef Havelka
Original assignee: Isotherm sro
Current assignee: Isotherm sro
Priority date: 2014-02-03
Filing date: 2015-01-28
Publication date: 2018-07-18
Anticipated expiration: 2035-01-28
Also published as: CZ305337B6; HUE040004T2; PL2910315T3; CZ201477A3; EP2910315A1

Description

Field of the invention

The invention relates to a self-cleaning tank for the continuous storage of technical cooling water supplied from machine tools of technological facilities and containing waste as solid particles from the processing or machining of materials which have a density greater than the density of water, in particular glass, ceramics, and stone.

Background of the invention

Currently, tanks for storing technical cooling water for machine tools of technological facilities for processing glass, stone, ceramics, and other materials are known which have a plan view shape of a quadrangle, particularly a rectangle, for the effective utilization of the ratio of occupied floor area to tank volume. Technical water containing particles of material is supplied to the tank. From this tank, the water is pumped into a cleaning device and to a system for cooling machine tools.
The disadvantages of the existing designs are that the rectangular shape of the tank prevents sufficient movement of the entire volume of water in the tank and results in the gradual sedimentation of waste particles in the tank, resulting in shutdowns of working lines due to the necessity of cleaning the tank. This leads to a loss in capacity of the manufacturing time of the technological facility. If the tank is not cleaned regularly, this results in the sedimentation of waste particles and the subsequent clogging of the cooling piping that leads water to the machine tools, damaged machine tools, or in the poor processing of products.
The object of the invention is to create a self-cleaning tank in which waste is not deposited as sludge from the particles of solid material washed out into cooling technical water after the machining process, which could store the cooling technical water continuously, which would be structurally simple and effective, and which would have low acquisition and operating costs.

Summary of the invention

This objective is solved by creating a self-cleaning tank according to the appended claims. The self-cleaning tank for the continuous storage of cooling technical water containing particles of solid material consists of an impermeable bottom and circumferential wall. The self-cleaning tank is equipped with at least one fluid inlet and at least one fluid outlet connected to the technological equipment, and at least one fluid inlet and at least one fluid outlet connected to the cleaning device. Simultaneously, each of the outlets is equipped to at least one pump.
The essence of the invention consists in that the plan view of the bottom and circumferential wall have a round shape and the circumferential wall is provided with a tangential chamber. The tangential chamber is separated by a dividing partition which lies on the plan view of the circumferential wall and the tangential chamber is formed by tangential walls which extend tangentially to the plan view of the circumferential wall and are connected together at a vertex situated opposite the dividing partition. Between the circumferential wall and an one end of the dividing partition is created an output vertical interrupt of the circumferential wall and between an opposite end of the dividing partition and the circumferential wall is created an input vertical interruption of the circumferential wall for a water flow through the tangential chamber, wherein the inlet of cleaned liquid from the cleaning device and outlet of cooling liquid to the technological equipment are led into the central area of the self-cleaning tank, and the inlet of cooling liquid from the technological equipment and outlet of contaminated liquid to the cleaning device lead into the tangential chamber, while at the same time the self-cleaning tank is provided with at least one means for rotating the volume of stored cooling technical water in the self-cleaning tank.
It is preferred that in the rotating volume of stored cooling technical water, most of the particles of solid material are concentrated by centrifugal force in a circumferential stream which washes the circumferential wall of the tank, thus from the center of the self-cleaning tank there can be drawn relatively clean technical water and to the center area of the tank can be returned cleaned water fed from an external cleaning station. In the tangential chamber, through which the circumferential current passes across the vertical interruption of the circumferential wall, the contaminated water is removed for cleaning and simultaneously into the tangential chamber there returns the contaminated water from the technological equipment, without breaking the circumferential flow and without forming disruptive vortices which would reduce the effectiveness of the continuous drift of contained solid particles. The means for rotating the volume of stored cooling technical water is arranged in the area of the tangential chamber and is formed by a nozzle extending from a pump whose output is directed in parallel with the circumferential wall of the self-cleaning tank in the direction from the tangential chamber to the self-cleaning tank. The current of water coming from the nozzle continuously supplies the energy needed to create and maintain the circumferential water flow. This maintains a constant circumferential speed of the current. The orientation of the nozzle allows for the seamless fusion of the current of the nozzle with the circumferential current in the tank outside the tangential chamber, therefore not vortices are formed which would interfere with the rotation of the volume of cooling technical water.
In another further preferred embodiment of the self-cleaning tank according to the invention, the plan of the bottom and the circumferential wall is divided into individual arc sectors forming arc angles, wherein the sizes of the vertical sections and dividing barriers is determined by the angles. When determining the size of the width of the vertical interruption of the circumferential wall, the size of the diameter of the self-cleaning tank is irrelevant, since the arc rate is always the same.
In another further preferred embodiment of the self-cleaning tank according to the invention, the pump for pumping the cooling water to the system of cooling the technological equipment is located in the middle of the self-cleaning tanks. The pump for discharging the contaminated cooling water to the cleaning device is located in the tangential chamber. The pumps are arranged in the areas of the self-cleaning tank, where the stored water with the required parameters of contamination occurs and which the pumps should suction from the self-cleaning tank.
In another further preferred embodiment of the self-cleaning tank according to the invention, the top of the connection of the tangential walls of the tangential chamber is rounded and the size of the angles defining the size of the vertical interruptions of the circumferential walls of the tank is equal. The optimum for circumferential flow of stored cooling technical water vertical interruptions of the circumferential wall which are the same vertical size. The tank is then usable for both directions of rotation of the cooling water according to the layout of the technological equipment. However, it is also possible in varying requirements for the use of the self-cleaning tank to modify the hydrodynamic conditions in the volume of the stored cooling technical water by changing their size.
In another further preferred embodiment of the self-cleaning tank according to the invention, the output velocity of the liquid at the nozzle of the pump is such that the resulting rotational speed of the volume of the stored cooling technical water is in the desired range for achieving self-cleaning from 0.5 m/s to 2 m/s. The resulting rotational speed of the cooling water is adjusted according to the ratio of the density of the material to the density of the water in order to separate the particles washed out from the processing.
In another further preferred embodiment of the self-cleaning tank according to the invention, the size of the diameter of the bottom of the self-cleaning tank, which is governed by the intensity of the contamination of the cooling water, by the size of the technological equipment, and by the available space, is in the range from 1 m to 4 m.
In another further preferred embodiment of the self-cleaning tank according to the invention, it is provided with a safety cover. The safety cover prevents personal injury as well as objects being dropped into the tank, which could disrupt the smooth rotation of the volume of stored water.
In another further preferred embodiment of the self-cleaning tank according to the invention, the floor and walls of the self-cleaning tank are made of a material from the group including plastic, steel, stainless steel, and may also be provided with a surface treatment from lacquer, laminate, waterproofing, etc.
The advantages of the self-cleaning tank according to the invention include almost zero sedimentation of particles of solid materials contained in the technical water, the possibility of continuous operation of the technological devices, low acquisition costs, easy serviceability, low operating costs, a high quality of relatively clean water discharged to the technological equipment, and the safe operation of the self-cleaning tank.

Description of the drawings

The invention is illustrated in the following drawings, wherein Fig. 1 depicts a functional diagram of the self-cleaning tank and Fig. 2 depicts a plan view of the self-cleaning tank.

Examples of the preferred embodiments of the invention

Fig. 1 depicts a diagram of the self-cleaning tank 1 while Fig. 2 shows a plan view of the same self-cleaning tank 1, used for storing technical water intended for cooling tools of technological equipment that processes particularly stone and glass, therefore generally materials which have a density greater than the density of water.
The bottom 2 and the wall 3 of the self-cleaning tank 1 are made of stainless steel. The diameter of the self-cleaning tank 1 is 2000 mm and its depth is 250 mm. In the middle of the self-cleaning tank 1 is located a pump 8 that pumps its discharge to a clean water outlet 5 with a low content of solid particles; the outlet 5 is connected to various technological equipment (cutters, grinders, etc.) which need this water for smooth operation. In the center of the self-cleaning tank 1 there also leads an inlet 6 of cleaned water which returns to the self-cleaning tank 1 from the external cleaning device. The self-cleaning tank 1 is provided with a plastic cover.
The self-cleaning tank 1 is fitted on its circumference with a tangential chamber 13. The tangential chamber 13 is formed by tangential walls 14 which extend tangentially to the plan of the circumferential wall 3 . The tangential walls 14 intersect and form a vertex 15, which, for better hydrodynamic properties, is rounded inside the tangential chamber 13. The tangential chamber 13 is separated by a dividing partition 12, into which from the self-cleaning tank 1 through the output interruption 10 of the circumferential wall 3 there enters a current of rotating stored water. In the tangential chamber 13 there is positioned a pump 9 with an outlet 7 for contaminated water into an external cleaning device and an inlet 4 for the contaminated water from the technological equipment.
In the direction of circumferential flow, in the tangential chamber 13 at the input vertical interruption 11 of the circumferential wall 3, there is arranged a means 16 - a nozzle for rotating the volume of stored cooling water. The nozzle is supplied with water from part of the discharge of the pump 9 of contaminated water and is attached to the self-cleaning tank 1 so that its output current is directed parallel to the circumferential wall 3 of the self-cleaning tank 1 .
The volume of stored water rotates in the self-cleaning tank 1 at a circumferential speed of 1 m/s, so the particles of glass or stone with a density approximately 2.5 times higher than the density of water and which are contained in the water are collected by centrifugal force against the wall 3 of the self-cleaning tank 1 , where they are carried by the current until they are suctioned up with the water by the pump 9 into the outlet 7 for contaminated water.
In the central area of the self-cleaning tank 1 there occur a minimum of particles of solid material, so the cooling water stored in the central area of the self-cleaning tank 1 can be regarded as clean water, and this technical water is not objectionable for use in associated technological equipment.
The size of the vertical interruptions 10 and 11 of the circumferential wall 3 of the self-cleaning tank 1 and the dividing walls 12 may be appropriately determined according to the size of the angle α , β , γ of the individual arc sectors whose vertex lies in the center of the tank 1, since with the varying diameter of the tank 1 their size in units of length also vary. In the embodiment example, the size of the angles α and β is 26°, so the size of the vertical interruptions 10 and 11 is 449 mm.

Industrial applicability

The self-cleaning tank according to the invention can be used in operations where technical water is used for cooling processed materials. The water, during the processing of the material and prior to being discharged back to the storage tank, washes out the solid waste particles that do not deposit in the self-cleaning tank, so the self-cleaning tank can be continuously used. The operation of the technological equipment does not stop due to tank cleaning.

Overview of the indications used in the drawings

1: self-cleaning tank
2: impermeable bottom of the self-cleaning tank
3: circumferential wall of the self-cleaning tank
4: inlet of cooling liquid from the technological equipment
5: outlet of cooling liquid to the technological equipment
6: inlet of cleaned liquid from the cleaning device
7: outlet of contaminated liquid to the cleaning device
8: pump for outlet of cooling liquid to the technological equipment
9: pump for outlet of contaminated liquid to the cleaning device
10: output vertical interruption of circumferential wall
11: input vertical interrupt of circumferential wall
12: dividing partition between the self-cleaning tank and tangential chamber
13: tangential chamber
14: tangential wall
15: vertex of connection of tangential walls of the tangential chamber
16: means (nozzle) for rotating the volume of stored cooling water

α: angle of arc sector for determining the size of the output vertical interruption of the circumferential wall
β: angle of arc sector for determining the size of the input vertical interruption of the circumferential wall
γ: angle of the arc sector for determining the size of the dividing wall

Claims

A self-cleaning tank (1) for the continuous storage of cooling technical water containing particles of solid material, consisting of an impermeable bottom (2) and circumferential walls (3), fitted with at least one fluid inlet (4) and at least one fluid outlet (5) connected to technological equipment, at least one fluid inlet (6) and at least one fluid outlet (7) connected to a cleaning device, wherein each of the fluid outlets (5, 7) is fitted with at least one pump (8, 9), characterized in that the plan view of the bottom (2) and the circumferential wall (3) have a substantially round shape, and that the self-cleaning tank (1) is fitted on its circumference with a tangential chamber (13), which is formed by two tangential walls (14) which extend tangentially to the plan of the circumferential wall (3), and that tangential walls (14) intersect and form a vertex (15), which is, for better hydrodynamics properties, rounded inside the tangential chamber (13), concurrently are created in the circumferential wall (3) a vertical output interruption (10) for passing of a current of rotating stored water from the self-cleaning tank (1) into the tangential chamber (13) and a vertical input interruption (11) for passing of a current of rotating stored water from the tangential chamber (13) into the self-cleaning tank (1), and a section of the circumferential wall (3) between the output interruption (10) and the input interruption (11) forms a dividing partition (12), wherein the inlet (6) from the cleaning device and the outlet (5) to the technological equipment are introduced into the center of the self-cleaning tank (1), and the inlet (4) from the technological equipment and the outlet (7) to the cleaning device are introduced into the tangential chamber (13), while at the same time the self-cleaning tank (1) is provided with at least one mean (16) for rotating the volume of stored cooling technical water in the self-cleaning tank (1), and wherein the pump (9) is positioned in the tangential chamber and connected to the outlet (7) of the cleaning device.
A self-cleaning tank according to claim 1, characterized in that the mean (16) for rotating the volume of stored cooling technical water is arranged in the area of the tangential chamber (13) and is formed by a nozzle extending from the pump (9), the output of which is directed parallel to the circumferential wall (3) of the self-cleaning tank (1) in the direction from the tangential chamber (13) into the self-cleaning tank (1).
A self-cleaning tank according to claim 2, characterized in that that the floor plan of the bottom (2) and the circumferential wall (3) are divided into individual arc segments forming the angles (α, β, γ), wherein the size of the output interruption (10) of the circumferential wall (3) is determined by the arc angle (α), the size of the input interruption (11) of the circumferential wall (3) is determined by the arc angle (β) and the size of the dividing partition (12) is determined by the size of the angle (γ).
A self-cleaning tank according to at least one of claims 1 to 3, characterized in that the pump (8) of the outlet (5) is situated in the middle of the self-cleaning tank (1).
A self-cleaning tank according to at least one of claims 1 to 4, characterized in that the vertex (15) of the connection of the tangential walls (14) of the tangential chamber (13) is rounded, and the sizes of the angles (α, β) defining the size of the interruptions (10, 11) of the circumferential wall (3) are mutually equal.
A self-cleaning tank according to claim 2, characterized in that the output speed of the fluid on the nozzle of the pump (9) is such that the resulting speed of rotation of the volume of stored cooled technical water is in the range from 0.5 m/s to 2 m/s .
A self-cleaning tank according to at least one of claims 1 to 6, characterized in that in that the diameter size of the bottom (2) of the self-cleaning tank (1) is in the range from 1 m to 4 m.
A self-cleaning tank according to at least one of claims 1 to 7, characterized in that it is provided with a safety cover.
A self-cleaning tank according to at least one of claims 1 to 8, characterized in that the bottom (2) and the wall (3) of the self-cleaning tank (1) are made of a material from the group including plastic, steel, stainless steel, and may also be treated with a surface coat from the group including lacquer, laminate, and rubber coating.