High-concentration micro-nano foam preparation device and preparation method thereof

Abstract

The invention discloses a high-concentration micro-nano foam preparation device and a preparation method thereof.The device comprises a liquid storage tank, a conveying pump, a micro-nano foam preparation unit and a micro-nano foam separation and recovery unit, a first bottom barrier plate is arranged in the liquid storage tank, and the micro-nano foam preparation unit is connected with the conveying pump and arranged on the side edge of the liquid storage tank; and the micro-nano foam separation and recovery unit is integrated at the upper part of the liquid storage tank and comprises a second barrier plate, a micro-nano foam collection tank, a foam overflow plate and a foam discharge liquid return pipe. The micro-nano foam separation and recovery unit is arranged, foaming liquid separated out through the foam overflow plate and the foam discharge liquid return pipe by means of the gravity liquid discharge effect is guided back to the liquid storage tank, gas-liquid separation is effectively achieved, and the dryness and concentration of discharged foam are remarkably improved. The device is compact in structure, low in energy consumption, large in dry density and suitable for industrial large-scale production, and the particle size of the prepared micro-nano foam is concentrated at 1-10 microns.

Description

Technical Field

[0001] This invention relates to the field of micro / nano foam preparation technology, and in particular to a high-concentration micro / nano foam preparation device and preparation method. Background Technology

[0002] Micro- and nano-foams typically refer to groups of fine foams with diameters ranging from 50 μm to 100 nm. They possess extremely large specific surface areas, high stability, and unique interfacial rheological properties, and are widely used in mineral flotation, wastewater treatment, oil extraction, and daily chemical cleaning. Existing micro- and nano-foam preparation technologies mainly face the following challenges: (1) High energy consumption in the preparation process: When using conventional high-pressure jet or ultrasonic cavitation equipment to prepare micro-nano foams, the energy demand is large and the preparation process requirements are high.

[0003] (2) It is difficult to balance concentration and dryness: Conventional methods often involve a large amount of liquid phase entrainment when preparing micro-sized foams, resulting in low foam dry density and affecting the use of micro-nano foams.

[0004] (3) Poor foam stability: Due to the Ostwald curing effect, small bubbles are prone to coalesce into large bubbles, causing foam collapse and widening of foam size distribution.

[0005] To address the aforementioned issues, there is an urgent need for a foam preparation device that can achieve efficient foam generation, increase foam dry density, and maintain micro-nano-scale dimensions. Summary of the Invention

[0006] To address the aforementioned technical shortcomings, the present invention aims to provide a high-concentration micro / nano foam preparation device and method, which has high preparation efficiency, low operating cost, and can generate high-dry-density, high-concentration micro / nano foam through a unique internal circulation separation structure.

[0007] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: This invention provides a device for preparing high-concentration micro / nano foams, comprising: Storage tank 1, used to contain foaming liquid; A delivery pump, the inlet of which is connected to the storage tank; The micro / nano foam preparation unit has its inlet connected to the outlet of the delivery pump, and is used to mix foaming liquid and gas to generate micro / nano foam, and spray the generated micro / nano foam back into the storage tank. A micro / nano foam separation and recycling unit is integrated at the top of the side wall of the storage tank to receive and process the foam overflowing from the storage tank. The micro / nano foam separation and recovery unit includes: A micro / nano foam collection tank, connected to the liquid storage tank, is used to receive overflow foam; A foam overflow plate is disposed at the bottom of the micro-nano foam collection tank and has an inclined angle to guide the liquid flow. The foam discharge liquid return pipe has one end connected to the lower end of the foam overflow plate and the other end connected to the interior of the storage tank, and is used to guide the liquid separated from the foam in the micro-nano foam collection tank back to the storage tank.

[0008] Preferably, a first baffle plate is provided at the bottom of the inside of the liquid storage tank. The first baffle plate is located between the liquid outlet of the liquid storage tank and the injection port of the micro-nano foam preparation unit, and is used to prevent bubbles from being sucked into the delivery pump.

[0009] The length of the first barrier plate extends beyond the nozzle of the micro / nano foam preparation unit to prevent the foam from directly entering the liquid inlet of the delivery pump.

[0010] Preferably, the micro / nano foam separation and recovery unit further includes a second barrier plate with a length ≥ cm. The second barrier plate is vertically disposed at the connection between the liquid storage tank and the micro / nano foam collection tank, and is used to sort the foam entering the micro / nano foam collection tank.

[0011] Preferably, the foam overflow plate is tilted at an angle of 3° to 7° relative to the horizontal plane, so as to use gravity to guide the foam discharge liquid back through the foam discharge liquid return pipe.

[0012] Preferably, the foam discharge liquid return pipe is a micro-diameter pipe with an inner diameter of 2mm to 5mm.

[0013] Preferably, the nozzle of the micro / nano foam preparation unit is set horizontally or vertically downward so as to spray the foam jet it generates into the storage tank.

[0014] Preferably, the capacity of the storage tank is 1000mL to 2000mL, and the capacity of the micro-nano foam collection tank is no more than 300mL.

[0015] Preferably, the device adopts a modular design, and the liquid storage tank, the micro / nano foam preparation unit and the micro / nano foam separation and recycling unit are detachably connected and can be flexibly assembled.

[0016] The present invention also provides a method for preparing high-concentration micro / nano foam using the aforementioned high-concentration micro / nano foam preparation device, comprising the following steps: a) Inject the foaming liquid into the storage tank; b) Start the delivery pump to deliver the foaming liquid to the micro / nano foam preparation unit, and introduce gas into it for mixing to generate a micro / nano foam jet that is sprayed into the storage tank. c) The micro-nano foam generated in the storage tank rises and overflows, and after being sorted by the second baffle plate, it enters the micro-nano foam collection tank of the micro-nano foam separation and recovery unit. d) The micro-nano foam entering the micro-nano foam collection tank is drained under the action of gravity. The separated liquid flows along the inclined foam overflow plate and flows back to the storage tank through the foam discharge liquid return pipe. At the same time, the high-concentration micro-nano foam after being concentrated by the discharge liquid is discharged from the outlet of the micro-nano foam collection tank.

[0017] Preferably, in step b), the liquid flow rate is controlled to be 1L / min to 3L / min, and the gas flow rate is controlled to be 0.1L / min to 0.5L / min.

[0018] Beneficial effects: 1. By setting up a foam overflow plate and micro-diameter pipe, and utilizing the gravity drainage effect, excess liquid phase carried by the foam is separated in real time and guided back to the storage tank, achieving highly efficient gas-liquid separation. Under an inlet air flow rate of 250 mL / min, the dry density of the prepared foam can reach 18.48 Kg / m³. This value is significantly lower than that of conventional devices, indicating that the discharged foam has extremely low liquid content and high concentration, which is beneficial for improving the efficiency of subsequent processes (such as mineral flotation and wastewater treatment).

[0019] 2. Through the synergistic effect of the micro / nano foam preparation unit and the unique separation and recovery structure, micro / nano-sized bubbles can be stably generated, and bubble coalescence can be effectively suppressed. The prepared foam particles are mainly concentrated in the range of 1–10 μm, with intact morphology and no obvious breakage. This fine and uniform particle size endows the foam with a large specific surface area and excellent interfacial activity.

[0020] 3. This solution abandons the traditional approach of requiring additional high-pressure equipment or energy-consuming components for gas-liquid separation, and fully utilizes gravity and capillary action (the drainage effect of the micro-diameter tube) to achieve liquid phase reflux self-circulation. As described in the background technology, the total power consumption of the device can be less than 200W, significantly reducing operating energy costs.

[0021] 4. By installing a first baffle plate at the bottom of the storage tank, a large number of bubbles generated at the injection nozzle are effectively prevented from being directly sucked into the delivery pump, ensuring the stability of the pumping system and the continuity of the foaming liquid circulation. The foam is allowed to settle and drain in the collection tank, and the separated liquid is automatically returned. The entire process requires no manual intervention, realizing continuous production. Furthermore, by setting a foam overflow plate at a specific angle (3°~7°) and a micro-diameter pipe with a specific inner diameter (2~5 mm), the return flow rate and foam accumulation rate are balanced, preventing pipeline blockage or airlock. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of a high-concentration micro / nano foam preparation device provided in an embodiment of the present invention; Figure 2 This is a graph showing the variation of the dry density of micro / nano foam under different air intake volumes in an embodiment of the present invention. Figure 3 This is a size distribution diagram of the micro / nano foams prepared in the embodiments of the present invention.

[0024] Reference numerals in the attached drawings: 1-Storage tank; 11-First baffle plate; 2-Liquid pipeline; 3-Transfer pump; 4-Micro-nano foam preparation unit; 5-Gas pipeline; 6-Gas flow meter; 7-Micro-nano foam separation and recovery unit; 71-Second baffle plate; 72-Micro-nano foam collection tank; 73-Foam overflow plate; 74-Foam discharge liquid return pipe. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] Example 1 like Figure 1 As shown, the present invention provides a high-concentration micro / nano foam preparation device, including a storage tank 1 with a capacity of 1000~2000mL, a delivery pump 3, a micro / nano foam preparation unit 4, and a micro / nano foam separation and recovery unit 7; the device adopts a modular design, and the storage tank 1, the micro / nano foam preparation unit 4, and the micro / nano foam separation and recovery unit 7 are detachably connected; The storage tank 1 is used to contain the foaming liquid; the delivery pump 3 is a diaphragm pump, and its inlet is connected to the storage tank 1 through the liquid pipeline 2. The inlet of the micro-nano foam preparation unit 4 is connected to the outlet of the delivery pump 3, and is used to mix the foaming liquid and gas to generate micro-nano foam, and spray the generated micro-nano foam back into the storage tank 1; The air inlet of the micro / nano foam preparation unit 4 is connected to a gas flow meter 6 via a gas pipeline 5; The micro / nano foam separation and recycling unit 7 is integrated at the top of the side wall of the liquid storage tank 1 and is used to receive and process the foam overflowing from the liquid storage tank 1. The micro-nano foam separation and recovery unit 7 includes a micro-nano foam collection tank 72, a foam overflow plate 73, and a foam discharge liquid return pipe 74. The micro-nano foam collection tank 72 is connected to the liquid storage tank 1 and is used to receive overflow foam; the capacity of the micro-nano foam collection tank 72 is no more than 300 mL. The foam overflow plate 73 is disposed at the bottom of the micro-nano foam collection tank 72 and has an inclined angle to guide the liquid flow. One end of the foam discharge liquid return pipe 74 is connected to the lower end of the foam overflow plate 73, and the other end is connected to the interior of the storage tank 1. It is used to guide the liquid separated from the foam in the micro-nano foam collection tank 72 back to the storage tank 1.

[0027] In addition, a first baffle plate 11 is provided at the bottom of the inside of the liquid storage tank 1. The first baffle plate 11 is located between the liquid outlet of the liquid storage tank 1 and the spray port of the micro-nano foam preparation unit 4, and is used to prevent bubbles from being sucked into the delivery pump 3.

[0028] The length of the first barrier plate 11 extends beyond the nozzle of the micro / nano foam preparation unit 4 to prevent the foam from directly entering the liquid inlet of the delivery pump.

[0029] The micro-nano foam separation and recovery unit 7 also includes a second barrier plate 71 with a length of 2cm. The second barrier plate 71 is vertically arranged at the connection between the liquid storage tank 1 and the micro-nano foam collection tank 72, and is used to sort the foam entering the micro-nano foam collection tank 72.

[0030] The foam overflow plate 73 is tilted at an angle of 5° relative to the horizontal plane so as to use gravity to guide the foam discharge liquid back through the foam discharge liquid return pipe 74.

[0031] The foam discharge liquid return pipe 74 is a micro-diameter pipe with an inner diameter of 3mm.

[0032] The nozzle of the micro / nano foam preparation unit 4 is set horizontally or vertically downward so that the foam jet it generates can be sprayed into the liquid storage tank 1.

[0033] Its working principle is as follows: the foaming liquid in the storage tank is pressurized by a delivery pump and fed into the micro / nano foam preparation unit to generate micro / nano foam, which is then returned to the storage tank for circulation. After the micro / nano foam accumulates, it floats to the surface and overflows into the micro / nano foam collection tank. During the process of entering the micro / nano collection tank, foam discharge liquid is generated. The discharge liquid is guided by the foam overflow plate and, under the action of pressure difference and gravity, flows back to the storage tank through the foam discharge liquid return pipe, which greatly increases the dry density and concentration of the prepared micro / nano foam.

[0034] Experimental test: 500 mL of foaming solution was added to the storage tank, and the diaphragm pump flow rate was adjusted to 1.7 L / min. The air inlet flow rate was adjusted to 100, 250, and 500 mL / min respectively, and samples were taken after running for 10 minutes until stabilization. Test results (see...) Figure 2 At an air intake rate of 250 mL / min, the dry density of the micro-nano foam is 18.48 Kg / m³.

[0035] Example 2 Based on Example 1, the liquid flow rate was maintained at 1.7 L / min and the gas flow rate at 100 mL / min. The morphology of the outlet foam was observed using a microscope (see Example 1). Figure 3 The foam morphology within the field of view is intact, with no obvious ruptures or mergers. Statistical analysis shows that the diameter of the micro- and nano-foams is mainly distributed in the range of 1 to 10 μm, which is typical of micro- and nano-foams.

[0036] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A device for preparing high-concentration micro / nano foam, characterized in that, include: Storage tank (1), used to contain foaming liquid; A delivery pump (3) has its inlet connected to the storage tank (1); The micro-nano foam preparation unit (4) has its inlet connected to the outlet of the delivery pump (3) for mixing foaming liquid and gas to generate micro-nano foam, and spraying the generated micro-nano foam back into the storage tank (1); The micro-nano foam separation and recycling unit (7) is integrated at the top of the side wall of the liquid storage tank (1) and is used to receive and process the foam overflowing from the liquid storage tank (1); The micro / nano foam separation and recovery unit (7) includes: The micro-nano foam collection tank (72) is connected to the liquid storage tank (1) and is used to receive overflow foam; A foam overflow plate (73) is disposed at the bottom of the micro-nano foam collection tank (72) and has an inclined angle to guide the liquid flow direction; The foam discharge liquid return pipe (74) is connected at one end to the lower end of the foam overflow plate (73) and at the other end to the interior of the storage tank (1), and is used to guide the liquid separated from the foam in the micro-nano foam collection tank (72) back to the storage tank (1).

2. The high-concentration micro / nano foam preparation device according to claim 1, characterized in that, The bottom of the liquid storage tank (1) is provided with a first barrier plate (11). The first barrier plate (11) is located between the liquid outlet of the liquid storage tank (1) and the spray port of the micro-nano foam preparation unit (4), and extends beyond the spray port of the micro-nano foam preparation unit (4) to prevent foam from directly entering the liquid inlet of the delivery pump.

3. The high-concentration micro / nano foam preparation device according to claim 1, characterized in that, The micro-nano foam separation and recovery unit (7) also includes a second barrier plate (71), which is vertically arranged at the connection between the liquid storage tank (1) and the micro-nano foam collection tank (72) for sorting the foam entering the micro-nano foam collection tank (72).

4. The high-concentration micro / nano foam preparation device according to claim 1, characterized in that, The foam overflow plate (73) is tilted at an angle of 3° to 7° relative to the horizontal plane so as to use gravity to guide the foam discharge liquid back through the foam discharge liquid return pipe (74).

5. The high-concentration micro / nano foam preparation device according to claim 1, characterized in that, The foam discharge liquid return pipe (74) is a micro-diameter pipe with an inner diameter of 2mm to 5mm.

6. The high-concentration micro / nano foam preparation device according to claim 1, characterized in that, The nozzle of the micro-nano foam preparation unit (4) is set vertically downward so that the foam jet it generates is sprayed into the liquid storage tank (1).

7. The high-concentration micro / nano foam preparation device according to claim 1, characterized in that, The capacity of the storage tank (1) is 1000mL to 2000mL, and the capacity of the micro-nano foam collection tank (72) is no more than 300mL.

8. The high-concentration micro / nano foam preparation device according to claim 1, characterized in that, The device adopts a modular design, and the liquid storage tank (1), the micro-nano foam preparation unit (4) and the micro-nano foam separation and recovery unit (7) are detachably connected.

9. A method for preparing high-concentration micro / nano foam using the high-concentration micro / nano foam preparation apparatus according to any one of claims 1 to 8, characterized in that, Includes the following steps: a) Inject the foaming liquid into the storage tank (1); b) Start the delivery pump (3) to deliver the foaming liquid to the micro-nano foam preparation unit (4) and introduce gas into it for mixing to generate micro-nano foam jets that are sprayed into the storage tank (1). c) The micro-nano foam generated in the storage tank (1) rises and overflows, and after being sorted by the second baffle plate (71), it enters the micro-nano foam collection tank (72) of the micro-nano foam separation and recovery unit (7); d) The micro-nano foam entering the micro-nano foam collection tank (72) is drained under the action of gravity. The separated liquid flows along the inclined foam overflow plate (73) and flows back to the storage tank (1) through the foam discharge liquid return pipe (74). At the same time, the high-concentration micro-nano foam after being drained and concentrated is discharged from the outlet of the micro-nano foam collection tank (72).

10. The method according to claim 9, characterized in that, In step b), the liquid flow rate is controlled to be 1L / min to 3L / min, and the gas flow rate is controlled to be 0.1L / min to 0.5L / min.

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