RU80775U1 - DEVICE FOR IMPREGNATION OF SHEET MATERIAL WITH SUSPENSION WITH NANODISPERSED PHASE - Google Patents

Abstract

The utility model relates to devices for applying liquid mono and modified media on the surface of materials using spraying means, in particular, to devices for applying a low-viscosity aqueous suspension containing nanodispersed metal powder and can be used for impregnation and coating of thin-sheet nonwoven polymeric materials. The proposed device for impregnating sheet material with a suspension with a nanodispersed phase contains a housing, means for supplying a suspension containing supply pipelines, means for supplying compressed air and a spray unit containing nozzles, the housing being made in the form of a box inside which a unit for accommodating sheet material is mounted, consisting of from the installation site and the replaceable cartridge, the spray unit is mounted on the box on the rails with the possibility of its movement in the longitudinal direction above the top By the fact of the sheet material placed on the removable cartridge, the device further comprises a discharge pipe to ensure constant circulation of the suspension in a closed loop. The device allows to impregnate a low-viscosity aqueous suspension containing nanosized metal powder of a sheet material, mainly non-woven polymer, ensuring the introduction and uniform distribution of the suspension phase throughout the sheet material. 8 pfp .; 4 ill.

Description

The utility model relates to devices for applying liquid mono and modified media on the surface of materials using spraying means, in particular, to devices for applying a low-viscosity aqueous suspension containing nanodispersed metal powder and can be used for impregnation and coating of thin-sheet nonwoven polymeric materials.

A device for coating [RU 2325957 C2, 2008], containing at least one coating unit with a coating material, which contains at least one metering head, which has at least one bubble-jet and / or a jet or piezoelectric jet nozzle that can be controlled in response to a computer generated control signal, and a device for moving a substrate having a surface to be coated along this surface relative to the metering head, and / or metering movement a head relative to the surface of the base to be coated; and a device for hardening the cover surface of the base by stitching the liquid coating material.

The device does not allow coating on large surfaces and does not allow coating with liquid substances with a viscosity of less than 1 Pa and provide a high degree of uniformity in such a coating by the mass of the substance over large areas (> 1 m ² ).

A device for preparing a sorbent is known [RU 14531 U1, 2000], in which nozzles are mounted on the perimeter for applying an impregnating substance (for example, an aqueous solution of latex), while the nozzles are fixed at a certain angle to the longitudinal axis of the body. The body of the device is made in the form of a segment of a pipe of rectangular cross-section with inlet and outlet hatches for moving the sorbent carrier (for example, in the form of a tape) with an optimal speed and has a positive inclination to the horizontal axis - (5 ÷ 30) °. The pressure at the outlet of the nozzles of the upper row is (10 ÷ 70)% lower than average. Previously, the sorbent carrier tape is refilled into the housing through the access hatch with

dimensions slightly exceeding the dimensions of the cross section of the carrier strip. The modes of pressure of the working mixture of impregnation and the performance of the supply of the gas mixture, for example air, drying, are adjusted. After turning on the device, the processed carrier tape under the action of the jets of the lower and side nozzles is maintained in suspension, due to the formation of an air cushion, the presence of a wall above the exit hatch plays a significant role. The jets from the upper nozzles provide, along with the horizontal component of gravity, the longitudinal movement of the tape.

The optimum speed of movement of the processed tape to a large extent depends on the angles of inclination of the body, nozzles, the pressure of the jets of the impregnating substance and the performance of the substance. The carrier moves with optimal speed towards the exit hatch under the action of gravity, as well as jets of impregnation and drying substances.

The disadvantages of this device, selected as a prototype, are the following:

1. The device allows you to process thick (bulk) tape with a "noticeable" weight of its short length (for example, 10 ... 20 cm), since when feeding the tape in the device uses the horizontal component of its weight. In the case of thin materials (carriers of sorbents, for example, non-woven materials - Petryanov’s fabric, non-woven fabric, etc.), the weight of their short segments is very small and cannot be used in the device as a component of the tape feed force.

2. The device cannot be used for feeding thin and wide strips with a thickness of (0.1 ... 0.4) mm and a width of about 1000 mm. Difficulties are associated with the flow of gas jets from the side nozzles. Under the influence of the pressure of such jets, the shape of the tape is not stable in the flow, crumpled.

3. The device cannot be used for processing tapes, especially thin and wide, with aqueous suspensions, when the material is further subjected to heat treatment in order to conduct a chemical reaction, for example hydrolysis. In the device, due to significant blowing of the strip with gases (up to 20 · 10 ³ m ³ / h), the material is dehydrated and as a result unfavorable conditions are created for a complete qualitative hydrolysis reaction.

4. The device cannot be used for the manufacture of multilayer dimensional canvases of sorption materials with horizontal dimensions of more than 1 m, when thin canvases (carriers) are pre-treated with suspensions, packaged, and then subjected to heat treatment in order to conduct chemical reactions in the time range from units to tens of minutes. AT

device, in gas flows, there is a change in the balance of the reagents and their distribution on the canvas. As a result, it is impossible to organize a high quality process at the stage of heat treatment of a multilayer blank sorbent blanks.

The objective of this utility model is to develop a device that allows impregnation with a low-viscosity aqueous suspension containing nanodispersed metal powder of a sheet material, mainly non-woven polymer, on one side and without its deformation.

EFFECT: embedded and evenly dispersed phases of a suspension.

This object is achieved in that, like the known, the proposed device for impregnating sheet material with a suspension with a nanodispersed phase contains a housing, means for supplying a suspension containing supply pipelines, means for supplying compressed air and a spray unit containing nozzles, characterized in that the body is made in the form box, inside which is mounted a node for placing sheet material, consisting of a mounting pad and a replaceable cartridge, the spray unit is mounted on the box on the guide them with the possibility of moving longitudinally on the replaceable cartridge disposed above the surface of the sheet material, the apparatus further comprising a discharge line to provide continuous circulation of the slurry in a closed circuit.

In addition, the spray block is a carriage mounted on the guide rails of the box in the transverse direction, on which nozzles are staggered, as well as supply and discharge pipelines of the suspension and pipelines for supplying compressed air.

In addition, nozzles of the pneumatic system are used in the spraying unit, in which compressed air is used to spray the liquid, with a circular torch in the cross section orthogonal to the axis of spraying.

In addition, the nozzles are mounted on the carriage at an angle of not more than 87 ° to the surface of the sheet material, in the direction opposite to the forward stroke of the carriage.

In addition, the replaceable cartridge is a frame with a metal mesh on which sheet material is placed.

In addition, the means for supplying the suspension contain a container for the suspension and pipelines leading to the nozzles, while a pump, a check valve, a filter, a valve for

opening channels for supplying a suspension, a pressure gauge, and a discharge pipe is connected to a container for the suspension.

In addition, the device includes a compressor for supplying compressed air to the spray unit, as well as means for controlling the pressure and flow rate of the suspension and means for controlling the speed of movement of the carriage.

In addition, it further comprises a roller fixed in the transverse direction along the carriage for partial extraction of the impregnated sheet material.

The proposed impregnation device allows you to implement a set of methods to solve the problem of uniform impregnation by spraying the overall sheet material with an aqueous suspension of nanopowder based on aluminum. The device was tested in the production technology of a composite sheet sorbent, in which a non-woven polymeric material with horizontal dimensions of 950 × 1500 mm obtained by the method of electroforming (Petryanov’s fabric) is used as the base, and the active phase of the sorbent distributed in the bulk of the base consists of oxide-hydroxide phases of aluminum. The production technology includes two main stages: suspension processing of sheet non-woven polymeric material and its subsequent heat treatment.

To solve this problem allows the use of a number of nozzles, which are installed in the carriage and fixed relative to each other in a checkerboard pattern. It is advisable to use nozzles of a pneumatic system in which compressed air is used to spray the liquid, with a circular torch in the cross section orthogonal to the spray axis and an outlet diameter of 1.2 mm. In figure 3. shows the configuration of the mutual arrangement of the nozzles in a horizontal section.

It was found that the axis of the nozzles should be located to the plane of the canvas at an angle of no more than 87 °. The angle of inclination is formed in the direction opposite to the direct movement of the carriage with nozzles. In the case of the orthogonal arrangement of the axis of the nozzles, there is a strong effect of the air-drop mixture of the flow on the sheet material. The phenomena of raising the sheet material, the formation of air cavities, crumpling, etc. are recorded. When the nozzles are inclined to the plane of the sheet material, the unwanted phenomena described above are reduced and the web is tensioned on the surface of the pallet. At angles less than 87 °, manifestations of uneven distribution of the active phases of the sorbent over the volume of sheet material begin. The staggered arrangement of nozzles, with other parameters unchanged, also contributes to uniform impregnation of the sheet material with a suspension. The optimum mixing of the axis of the nozzles along the direction of movement of the nozzles is 23-27 mm, preferably 25 mm. In options that differ from the value

of this displacement, the results are obtained on the uniformity of the distribution of the active phase of the sorbent in the web volume worse than the average obtained at a displacement of ≈25 mm. It was determined that, with other constant significant device parameters, the optimal distance from the nozzle exit to the surface of the impregnated sheet material is 165-175 mm, preferably 170 mm. figure 2. At distances <165 mm, sharp contact boundaries of nozzle flares are fixed, large concentrations of the active phase of the sorbent in these places and the heterogeneity of their content throughout the volume are dense. In the case of distances to the sheet material> 175 mm, there are large airborne droplets over the web, displacement of the mixture flow to the periphery of the web, its crushing and uneven distribution of the sorbent in the web over its volume, and the optimal distances between the nozzles are: 90-94 mm, preferably 92 mm.

Difficulties in impregnation of a suspension containing a nanodispersed phase are associated with a noticeable sedimentation of the powder and the need to ensure uniform distribution of the nanopowder over the volume of sheet material having significant horizontal dimensions (950 × 1500 mm). Technically, it is necessary to organize a system in which the powder is constantly maintained in suspension and fed into the nozzle system. For this purpose, the device is additionally equipped with means that allow it to be constantly mixed (for example, an electromechanical mixer) before feeding the suspension into the nozzle system. The system also includes a pump for supplying the suspension to the nozzles in a closed circuit under excessive pressure. When the nozzle system is turned off for a short time (the electromechanical valve is turned off), the pump does not turn off, and the suspension circulates along the short circuit formed: mixer — check valve — mixer.

Thus, uniform impregnation of the web is achieved both by the geometry of the nozzles relative to each other and the surface of the sheet material, and by the formation of a pneumohydraulic system of the device with constant circulation of the suspension.

A pump and compressor are used to control the pressure of the slurry and compressed air.

The electric carriage allows you to control the speed of its movement.

In addition, the device further comprises a roller fixed in the transverse direction along the carriage for partial extraction of the impregnated sheet material.

The invention is illustrated in graphic materials.

Figure 1 presents a General view of the device.

Figure 2 is a schematic illustration of the structure of the device on the side.

Figure 3 shows the configuration of the mutual arrangement of the nozzles in a horizontal section (figure 2).

In figure 4. The pneumohydraulic diagram of the device is presented.

The proposed device consists of a housing made in the form of a box 1 (Fig. 1, 2, 4), containing a mounting pad 2 (Fig. 2) for placement on it of a replaceable cartridge 3 (Fig. 1, 2) with impregnated sheet material 4 (Fig. 2) and a spray unit (carriage) 5 (Fig. 1) mounted on guides 6 (Fig. 1) having an electric drive 7 that moves the spray unit in the longitudinal direction along the duct 1 above the surface of the impregnated material 4. The spray unit 5 contains a number of nozzles 8 (figure 1, 2), a channel for supplying a suspension (pipeline) 9 (figure 1, 2) , a channel (pipeline) for supplying compressed air 10 (Fig.1, 2) and a roller 11 (Fig.1,2) for partial extraction of sheet material 4.

Additionally, the device also includes: an electromechanical mixer with a capacity of 12 (Fig. 4), a pump for pumping the suspension 13, a check valve 14, a filter 15 installed in the pipeline for supplying the suspension to the nozzles 8, a compressor 16, electrically controlled valves for opening channels (pipelines ) supply of the suspension and compressed air 17, 17 ', pressure gauges 18, 18', a container for collecting excess suspension 19 and a filter 20.

The device operates as follows.

The previously prepared aqueous suspension of aluminum nanopowder is poured into a container 12 with a mixer (not shown) (Fig. 4) and the drive of the mixer is turned on. The compressor 16 is turned on and ready to be connected to the spraying unit system through the valve 17 '(the suspension is supplied to the nozzles under an overpressure of (1.5-1.8) MPa.

The processed sheet material - Petryanov’s fabric (FPA - 15-2.0) of 950 × 1500 mm in size is laid on the metal mesh of the replaceable cartridge 3 (Fig. 2), which in turn is installed on the installation pad 2 in the box 1. The valve 17` opens (Fig.4) - compressed air is supplied to the system of the spraying unit 5. The valve 17 is turned on, after a pause necessary to start the operation of the nozzles 8, the electric drive 7 of the carriage of the spraying unit 5 is turned on and it moves along the sheet material at a speed of 5 cm / sec. At high speeds, undesirable dynamic loads occur at the start and stop stages of the carriage. At the edge of the sheet material, the carriage electric drive turns off simultaneously with the valve 17` turned off and, after a pause, by the valve 17.

The carriage return stroke (spray unit) 5 is turned on to return to its original state. With this movement of the carriage (spray unit) 5 lowers

the roller 11 (Fig.1, 2) for partial extraction of the canvas. After the carriage returns (spray unit) 5, a new layer of sheet material 4 is laid and the whole sequence of operations is repeated. The device was tested in the technology of obtaining 8-layer composite sheet sorbents. After impregnation, the material is placed in a thermal furnace and aged in it until the completion of the hydrolysis reaction of the nanodispersed phase.

The quality of the obtained material was determined by the method based on weighing the residues during the burning of images (pieces of cloth) taken from different places by area. The residue, when burned, is alumina. According to its quantitative distribution over the area of the material, a conclusion is drawn on the quality of the technological process of its impregnation. Test procedure: its content, initial conditions and content of the processes were based on the results of preliminary work on the development of the material and the technical methods of its manufacture. In the volume of material, it is possible to obtain a reliably retained phase of aluminum hydroxide in an amount of ≈22%, mass. Test data on the content of hydrate of aluminum oxide - Al ₂ O ₃ ,%, mass. in sheet material in different areas along the surface are shown in the Table.

Table. Technical parameters of the device: air pressure in the pneumatic system-2 MPa; the distance from the nozzle of the nozzle to the surface of the canvas - 170 mm; carriage speed - 5 cm / sec; nozzle displacement in a checkerboard pattern (in the direction of carriage movement) - 25 mm. Place of sampling on the material web. The distance between the nozzles, mm. 92 110 150 Pressure in the suspension supply system, MPa. 1,5 1,5 1,5 Upper left edge. 21.8 20.5 19.1 Upper right edge. 23.5 25,2 26.2 Middle left. 22.7 19.3 18.7 Middle, center. 22.0 21.9 22.8 Middle right. 24.2 26.7 27.0 Lower left edge. 21.6 18.7 18.5 Bottom right 20.5 25.9 17.0 The average content of alumina,% mass. ≈22.4 ≈22.6 ≈21.3 Maksim. Relative error (scatter) in the content of alumina,%. 15.3 thirty 37

The table shows that a more uniform distribution of surface density and content is achieved by using the optimal geometric values of the configuration of the pneumohydraulic system.

Claims (8)

1. A device for impregnating a sheet material with a suspension with a nanodispersed phase, comprising a housing, means for supplying a suspension containing supply pipelines, means for supplying compressed air and a spray unit containing nozzles, characterized in that the housing is made in the form of a box inside which the assembly for mounting is mounted sheet material, consisting of a mounting pad and a replaceable cartridge, the spray unit is mounted on the box on the rails with the possibility of its movement in the longitudinal direction above erhnostyu sheet material disposed on the replaceable cartridge, the apparatus further comprising a discharge line to provide continuous circulation of the slurry in a closed circuit. 2. The device according to claim 1, characterized in that the spray unit is a carriage mounted on the guide rails of the box in the transverse direction, on which nozzles are staggered, as well as supply and discharge pipelines of the suspension and pipelines for supplying compressed air. 3. The device according to claim 1 or 2, characterized in that the spray unit uses nozzles of a pneumatic system in which compressed air is used to spray the liquid, with a circular torch shape in cross section orthogonal to the axis of spraying. 4. The device according to claim 1 or 2, characterized in that the nozzles are mounted on the carriage at an angle of not more than 87 ° to the surface of the sheet material in the direction opposite to the forward stroke of the carriage. 5. The device according to claim 1, characterized in that the replaceable cartridge is a frame with a metal mesh on which sheet material is placed. 6. The device according to claim 1, characterized in that the means of supplying the suspension contain a container for the suspension and pipelines leading to the nozzles, while in the supply part of the flow system, a pump, a check valve, a filter, a valve for opening the suspension supply channels, a pressure gauge are successively installed wherein the outlet of the outlet pipe is in communication with the capacity for the suspension. 7. The device according to claim 1, characterized in that it contains a compressor for supplying compressed air and suspension to the spray unit, and also contains means for controlling pressure and flow and means for controlling the speed of the carriage. 8. The device according to claim 1, characterized in that it further comprises a roller fixed in the transverse direction along the carriage for partial extraction of the impregnated sheet material.