CN115157443A - A device suitable for preparing water-based foam and mixing it with cement slurry - Google Patents

Abstract

The invention discloses a device suitable for preparing water-based foam and mixing and stirring the water-based foam and cement slurry, which comprises a gas cylinder, a flask, a foam chamber and a stirring cylinder, wherein inert gas is filled in the gas cylinder, a gas outlet of the gas cylinder is sequentially communicated with a gas inlet pipe and a T-shaped three-way pipe, the other two ends of the T-shaped three-way pipe are respectively communicated with a foaming liquid inlet pipe at the opening of the flask and an opening pipeline at the left lower end of the foam chamber, foaming liquid is filled in the flask, a plurality of layers of porous media with gradually increasing porosity are arranged in the foam chamber, fillers are arranged between the adjacent layers of porous media, a discharge pipe is arranged at the bottom of the foam chamber, a foam outlet pipe is arranged at the middle upper end of the foam chamber, the foam outlet pipe is communicated with the stirring cylinder, a slurry inlet is arranged at the upper end of the stirring cylinder and is used for inputting the cement slurry, and a slurry outlet is arranged at the lower end of the stirring cylinder. The device can prepare uniform, fine and stable carbon dioxide water-based foam and foam cement slurry with low foam breaking rate, large contact area and uniform mixing.

Description

A device suitable for preparing water-based foam and mixing it with cement slurry

technical field

The invention belongs to the field of foaming equipment and stirring equipment, and particularly relates to a device suitable for preparing water-based foam and mixing it with cement slurry.

Background technique

Under the same water-cement ratio, the foamed cement slurry has lower permeability and higher strength. Foamed cement slurry with different specific gravity can fully meet the requirements of different working performances such as compressive strength, permeability and fluidity. Foamed cement slurry has been widely used as a new material. At the same time, due to fuel combustion and clinker calcination in cement production, a large amount of gases that pollute the environment, such as carbon dioxide gas, will be produced. In order to reduce carbon emissions in the air and protect the environment, we try to use these gases to make water-based foams to prepare light The method of preparing foam synchronous grouting slurry from lightweight foamed cement slurry and achieved results. However, most of the water-based foams prepared by the existing foaming equipment do not have a uniform foam structure, high foaming multiples and a certain stabilization time, and the prepared water-based foams cannot meet the quality requirements required by the project. When mixing and stirring, the equipment is mostly added at one time. When the two are mixed, the foam is easily broken during mixing, and the foam breaking rate is high. The contact area between the water-based foam and the cement slurry is small, and the properties of the foamed cement slurry obtained by mixing and stirring cannot To meet the engineering requirements, manual stirring is often required in order to obtain better quality foamed cement slurry for experiments. At the same time, the current technology can hardly achieve the same pace of foaming and mixing and stirring, that is, after the foaming is completed, the foam is added while the cement slurry is added. Pass into the mixer to ensure less material loss and less equipment wear.

Therefore, there is a need for a foaming device that can prepare fine, uniform and stable water-based foam and a mixing device with a simple structure, less foam rupture during mixing and stirring, and a large contact area between the foam and the cement slurry. In step.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to provide a device suitable for preparing water-based foam and mixing it with cement slurry. The device provides the gas required for preparing the foam through different gas cylinders; Foaming liquid; fine, stable and uniform water-based foam is prepared by a foamer; the prepared water-based foam is mixed with cement slurry by a mixer to obtain a low foam breaking rate, a large contact area between the foam and the cement slurry, and various properties. Foamed cement slurry that can meet engineering needs; control the pace of foaming and mixing through designed work steps. In addition, the device has a simple structure design and low cost.

In order to solve the above-mentioned technical problems, the technical scheme adopted in the present invention is:

A device suitable for preparing water-based foam and mixing it with cement slurry, comprising a gas cylinder, a flask, a foam chamber and a stirring drum, the gas cylinder is filled with inert gas, and the gas cylinder outlet is connected to the The gas inlet pipe is communicated with the T-shaped tee pipe, and the other two ends of the T-shaped tee pipe are respectively communicated with the foaming liquid inlet pipe at the opening of the flask and the open pipe at the lower left end of the foam chamber. Foaming liquid, the flask is provided with a constant temperature heater, the foam chamber is provided with multiple layers of porous media with gradually increasing porosity, and fillers are provided between adjacent layers of porous media, and the foam chamber is The bottom is provided with a discharge pipe, the middle and upper ends of the foam chamber are provided with a foam outlet pipe, the air outlet of the gas cylinder is provided with a gas cylinder valve, the outlet of the flask is provided with a flask valve, and the foam outlet pipe is provided with a gas cylinder valve. There is a foam outlet pipe valve at the place, the foam outlet pipe is communicated with the mixing drum, the upper end of the mixing drum is provided with a slurry inlet for inputting cement slurry, and the lower end of the mixing drum is provided with a slurry outlet.

Further, the mixing drum is placed horizontally, and a horizontally placed hollow screw rod is arranged in the mixing drum. Both the mixing drum and the hollow screw rod are connected to the rotating shaft of the bearing, and the bearing is powered by a motor, so The foam outlet pipe extends into the mixing drum, the foam outlet pipe is communicated with the hollow screw rod, and the hollow screw rod is evenly provided with bubble holes.

Preferably, the bearing includes an inner rotating shaft and an outer rotating shaft that rotate in opposite directions, the inner rotating shaft is connected with the hollow screw rod, the outer rotating shaft is connected with the mixing drum, and the hollow screw rod is connected to the mixing drum. The outer wall is provided with a plurality of inner shaft blades, and the inner wall of the mixing drum is provided with a plurality of outer shaft blades.

Preferably, the inner shaft blade is a spiral stainless steel blade, and the outer shaft blade is a rectangular stainless steel blade.

Preferably, the porous medium is a multi-layer steel mesh, and the filler is steel wool, which is uniformly filled between adjacent layers of the steel mesh.

Further, the upper right part of the mixing drum is provided with a density detector and a PH detector, and the gas cylinder is provided with an air pressure controller.

Further, the mixing drum is provided with a rectangular hole, the outer side of the mixing drum is hingedly provided with a rectangular plate at a position close to one side of the rectangular hole, and the pH detector is detachably arranged on the inner side of the rectangular plate, so the The outer side of the mixing drum is fixed with a convex block at the position close to the other three sides of the rectangular hole, the convex block is provided with a groove, and the inner side of the rectangular plate is provided with a 3/4-circle convex ring, and the convex ring is arranged with the convex ring. The grooves are matched with each other, a locking hole is provided on the convex ring, and a locking catch is provided on the convex block, and the locking hole is matched with the locking catch.

Preferably, the reading of the air pressure controller is 0.2kpa, and the foaming liquid used in the flask includes 4g/L foaming agent tea saponin, 5g/L foam stabilizer dodecyl, 2g/L foaming agent The thickening agent sodium polyacrylate, the temperature of the constant temperature heater is set to 25 degrees Celsius.

Further, the method for preparing foamed cement slurry is:

Step A: Pour inert gas into the foaming liquid to prepare foam, calculate the foaming ratio Y of the foaming liquid, and mix and stir the prepared foam with the cement slurry according to the foam-to-slurry ratio of 5:1 to obtain the foamed cement slurry for the test. , and measure the density Z of the foamed cement slurry;

Step B: prepare the consumption X of the foamed cement slurry and the density Z of the foamed cement slurry based on the plan of the laboratory, calculate the amount of foam required for the experiment, and the amount of foam is 0.83X, and make foaming liquid accordingly;

Step C: Fill the gas cylinder with inert gas, close the valve of the gas cylinder, and adjust the air pressure controller so that the air pressure in the gas cylinder is 0.2kpa;

Step D: connect the gas cylinder with the gas inlet pipe, then connect the gas inlet pipe with the T-shaped tee pipe, and then connect the other two branches of the T-shaped tee with the foaming liquid inlet pipe and foam at the opening of the flask respectively. The open pipe at the lower left end of the chamber is connected, and the flask valve is closed;

Step E: Based on the amount of foam required in the experiment of Step B, select a foam chamber with a suitable volume to communicate with the T-shaped three-way pipe;

Step F: open the valve of the gas cylinder and the valve of the flask at the same time, close the valve of the foam outlet pipe, and prepare the foam;

Step G: The inert gas is pushed by the air pressure, and the foam enters the foam chamber and gradually rises, passing through the porous medium and the filler;

Step H: As the porosity gradually increases, the pore size of the foam becomes larger and uniform;

Step 1: obtain a fine, stable, uniform water-based foam, which is stored in the interior of the foam chamber;

Step J: Calculate the water, cement, and light magnesium oxide required for mixing based on the ratio of foam to slurry 5:1 and water-to-binder ratio of 1:2.4, light magnesia 15%, fly ash 25%, and cement 60% and the amount of fly ash and have it ready;

Step K: mixing and stirring water, cement, light magnesia and fly ash, and configuring to obtain cement slurry;

Step L: Open the valve of the foam outlet pipe, and pour the prepared cement slurry into the slurry inlet;

Step M: Turn on the motor, the hollow screw rod rotates clockwise, the mixing drum rotates counterclockwise, the foam is discharged from the foaming circular hole, and spirally moves forward together with the cement slurry;

Step N: read the density of the foamed cement slurry according to the reading of the density detector;

Step 0: read the pH value of the foamed cement slurry according to the pH detector;

Step P: the prepared foamed cement slurry is discharged from the slurry outlet, and the motor is turned off;

Step Q: Obtain the desired foamed cement slurry.

Preferably, the calculation formula in the process of preparing foamed cement slurry is:

C=0.426X×Z

D=0.1775X×Z

E=0.1065X×Z

Among them, X is the volume of the foamed cement slurry planned to be prepared in the experiment, Y is the foaming ratio of the foaming liquid, Z is the density of the foamed cement slurry measured by the test, K is the density of the foaming liquid, and A is the experimental requirement. The volume of foaming liquid, B is the mass of water required for mixing cement, C is the mass of cement required, D is the mass of required fly ash, and E is the mass of light magnesium oxide required.

Compared with the prior art, the present invention has the following beneficial effects:

The technical problem to be solved by the present invention is to provide a device suitable for preparing water-based foam and mixing it with cement slurry. The device provides the gas required for preparing the foam through different gas cylinders; Foaming liquid; fine, stable and uniform water-based foam is prepared by a foamer; the prepared water-based foam is mixed with cement slurry by a mixer to obtain a low foam breaking rate, a large contact area between the foam and the cement slurry, and various properties. Foamed cement slurry that can meet engineering needs; control the pace of foaming and mixing through designed work steps. In addition, the device has a simple structure design and low cost.

Description of drawings

1 is a schematic diagram of a device of the present invention that is suitable for preparing water-based foam and mixing it with cement slurry;

Figure 2 is a schematic diagram of the interior of the foam chamber of the present invention;

Fig. 3 is the self-made pH meter style and measuring principle of the present invention.

1-gas cylinder, 2-air pressure controller, 3-gas cylinder valve, 4-gas inlet pipe, 5-T-type tee pipe, 6-flask, 7-thermostatic heater, 8-flask valve, 9-foaming Liquid inlet pipe, 10-foam chamber, 11-porous medium, 12-filler, 13-discharge pipe, 14-foam outlet pipe, 15-foam outlet pipe valve, 16-bearing, 17-slurry inlet, 18- Inner shaft blade, 19-bubble round hole, 20-outer shaft blade, 21-mixing drum, 22-hollow screw rod, 23-density detector, 24-pulp outlet, 25-PH detector, 26-motor.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

Example 1

The embodiment of the present invention provides a foaming and mixing equipment, as shown in FIG. 1 , wherein the equipment for providing gas is a gas cylinder 1, and the gas cylinder 1 is equipped with a gas pressure controller 2 and a gas cylinder valve 3; the equipment for providing foaming liquid For the flask 6, a constant temperature heater 7, a movable bottom plate and a flask valve 8 are placed; Porous medium 11, filler 12, discharge pipe 13, foam outlet pipe 14 and foam outlet pipe valve 15; the device provides gas raw material for foaming through the gas cylinder 1, and the air pressure during ventilation is controlled based on the air pressure controller 2, Control the ventilation speed based on the gas cylinder valve 3, feed gas based on the gas inlet pipe 4, store the foaming liquid based on the flask 6, control the foaming liquid temperature based on the constant temperature heater 7, control the flask based on the movable bottom plate 6 switches, control the speed of feeding liquid based on the flask valve 8, feed the foaming liquid based on the foaming liquid inlet pipe 9, and connect the gas inlet pipe 4, the foaming liquid inlet pipe 9 based on the T-shaped tee pipe 5 , the foaming cylinder is connected, based on the foam chamber and its movable bottom plate 10 to store the prepared water-based foam, based on the porous medium 11 and the filler 12 to make the prepared foam fine, uniform and stable, based on the foaming cylinder Carry out the whole process of foaming, the discharge pipe 13 can discharge the diluent that is not fully foamed, the liquid that is not fully foamed is discharged based on the discharge pipe 13, the foam is passed into the mixer based on the foam outlet pipe 14, and the foam is fed into the mixer based on the foam outlet pipe 14. The foam outlet pipe valve 15 controls the inflow time.

As shown in Figure 2, the bottom of the foam chamber 10 is provided with a movable baffle plate, and the foam outlet pipe 14 is provided with a valve, which can better store the foam in the foam chamber. After the cement slurry is mixed, the valve is opened, which can accurately control the The foam and the cement slurry are fed into the mixer at the same time, which effectively reduces the loss of materials and the wear of equipment. The foam chambers 10 have various volumes, and the foam chambers 10 are detachable, and the foam chambers 10 of different volumes can be precisely selected and installed in the foamer according to the amount of foam required by the project. A piston is provided on the left side of the foam chamber 10, and a scale is provided on the surface. After the valve is opened, the foam can be precisely pushed into the subsequent mixer by compressing the piston.

Specifically, the air pressure controller 2 is arranged on the upper left side of the gas cylinder 1, the gas cylinder valve 3 is located at the outlet of the gas cylinder 1, the gas cylinder 1 is connected with the gas inlet pipe 4, and the gas The right side of the inlet pipe 4 is connected with the left end guide of the T-shaped tee pipe 5 , and the gas cylinder 1 is supplied with the required gas based on the gas inlet pipe 4 . The thermostatic controller 7 is arranged on the outside of the flask 6, the flask valve 8 is arranged at the outlet of the flask 6, the flask 6 is connected with the foaming liquid inlet pipe 9, and the foaming liquid inlet pipe 9. The lower part is connected with the upper guide port of the T-type three-way pipe 5, and the right side guide port of the T-type three-way pipe 5 is connected with the foaming cylinder to complete the introduction and foaming of raw materials; the The foaming cylinder is placed vertically (the direction of gas-liquid movement is opposite to the direction of gravity of the steel plate), the bottom is the discharge pipe 13, the interior is the filler 12 and the porous medium 11, and the top is the foam chamber and its baffle 10 , the vertical gas-liquid flow direction is opposite to the gravity direction, which is equivalent to the introduction of bubbling effect, which is conducive to the generation of foam. The arrangement of the T-shaped tee pipe 5 has the advantages of simple structure, easy fabrication and low cost, and can simultaneously introduce gas and foaming liquid into the foamer to control the quality of the obtained foam.

Preferably, the flask 6 is upside down, and the side wall of the flask is marked with a scale, so that it is relatively easy and convenient to introduce the foaming liquid, and the volume of the foaming liquid to be introduced can be precisely controlled.

Further, the gas filled in the gas cylinder 1 is carbon dioxide, the reading of the air pressure controller 2 is adjusted to be 0.2kpa, the foaming liquid ratio adopted in the flask 6 is tea saponin 4g/L, and the selected foam stabilizer ratio is ten. Dialkyl 5g/L, thickener is sodium polyacrylate 2g/L, adjust constant temperature heater 7 to control the temperature to be constant at 25 degrees Celsius, provide carbon dioxide gas through gas bottle 1, and provide the foamed liquid through flask 6, the two Mix to foam. The foaming liquid is non-toxic and non-polluting.

Further, the filler 12 is steel wool, and the porous medium 11 is steel mesh. The steel mesh is provided with three layers, and the apertures of the steel mesh are respectively 0.1 mm, 0.5 mm and 1.0 mm from bottom to top. Steel wool is filled between the steel meshes. A steel mesh is arranged in the foam chamber 10, and steel wool is filled between the steel meshes. The porosity of the steel mesh gradually increases. The simultaneous action of the steel mesh and the steel wool can form a turbulent vortex, and as the porosity gradually increases, The pore size of the foam becomes larger and uniform. The porous medium 11 is made of steel mesh, and the filler 12 is made of steel wool, considering the practicality and economical applicability of the project.

The mixing device of the present invention includes a bearing 16, a slurry inlet 17, an inner shaft blade 18, a bubble outlet hole 19, an outer shaft blade 20, a mixing drum 21, a hollow screw rod 22, a density detector 23, a slurry outlet 24, PH Detector 25 and motor 26 . The mixing device controls the rotation of the mixing drum 21 and the hollow screw rod 22 through the bearing 16 , introduces the cement slurry that is not mixed with the foam through the slurry inlet 17 , and makes the foamer through the bubble outlet 19 . The prepared foam flows out, and the cement slurry and the foam are mixed and stirred through the inner shaft blade 18 and the outer shaft blade 20 , the blades are rotated through the rotation of the mixing drum 21 and the hollow screw rod 22 , and discharged through the slurry outlet 24 The prepared carbon dioxide foamed cement slurry is provided with the power to drive the mixing drum and the hollow spiral to rotate through the motor 26 , and the related properties of the foam are measured by the density detector 23 and the pH detector 25 .

Specifically, the mixing drum 21 is placed horizontally as a whole, and the left end is connected to the foam outlet pipe 14 in the foaming device. The hollow screw rod 22 is located inside and connected to the right end of the foam outlet pipe 14. 19 are evenly arranged on the hollow screw rod 22, and a motor 26 is arranged at the right end of the mixing drum 21. The slurry inlet 17 and the slurry outlet 24 are located at the upper left and lower right of the mixing drum, respectively. The density detector 23 and the pH detector 25 are respectively arranged inside the mixing drum, at the upper part of the rightmost end of the mixing drum.

The inner shaft blade 18 is arranged outside the hollow screw rod 22 , and the outer shaft blade 20 is arranged inside the mixing drum 21 .

The bearing 16 is divided into an inner bearing and an outer bearing, wherein the inner bearing controls the rotation of the hollow screw rod 22 , and the outer bearing controls the rotation of the mixing drum 21 . The motor 26 provides power, the bearing 16 controls the hollow screw rod 22 and the mixing drum 21 to rotate in opposite directions, drives the inner shaft blade 18 and the outer shaft blade 20 to rotate, and injects the cement slurry through the slurry inlet 17, The foam is precipitated through the foaming circular hole 19, the cement slurry and the foam are mixed and stirred by the rotation of the inner shaft blade 18 and the outer shaft blade 20, the carbon dioxide foamed cement slurry is discharged through the slurry outlet 24, and is detected by the density detector 23 and PH. The meter 25 measures the relative properties of the prepared foamed grout.

The inner and outer bearings respectively control the rotation of the hollow screw rod 22 and the mixing drum 21 to improve the stability of the device. The use of the motor 26 to control the rotation of the hollow screw rod 22 and the mixing drum 21 reduces labor consumption. There is a bubble hole 19 in the center of the pitch of each spiral blade as the foam outlet, which increases the contact area between the foam and the cement slurry, makes the foam evenly distributed, and reduces the foam breaking rate. The hollow screw 22 and the mixing drum 21 rotate in opposite directions, which also increases the contact area between the foam and the cement slurry, and improves the mixing uniformity of the foam and the slurry. The inner shaft blade adopts a spiral shape, which significantly improves the stirring efficiency, increases the contact area, and reduces the foam breaking rate. The inner and outer shaft blades are made of stainless steel, which reduces the possibility of rusting and strength reduction after long-term contact with foam.

Further, the diameter of the foaming circular hole 19 is 1.0 mm, so that the previously prepared foam can be precipitated.

Further, the inner shaft blade 18 is spiral, the outer shaft blade 20 is rectangular, and the materials used are all stainless steel, which can increase the stirring area, reduce the foam breaking rate, improve the stirring efficiency, and prevent the blades from rusting and reduce the strength. .

Further, the rotation direction of the mixing drum 21 is counterclockwise, and the rotation direction of the hollow screw rod 22 is clockwise. It also increases the stirring contact area, and the mixing is more uniform and sufficient.

Further, the density detector 23 is a tuning fork densitometer, the model of the tuning fork densitometer is LDS-2100 type tuning fork densitometer, and the density measurement range is 0-3 g/cm 3 . The pH meter uses pH test paper to measure the pH value of the foamed cement slurry.

As shown in FIG. 3 , the pH tester 25 can be detachably placed in the mixing tank 21 . Preferably, the mixing drum 21 is provided with a rectangular hole, the outer side of the mixing drum 21 is hingedly provided with a rectangular plate at a position close to one side of the rectangular hole, and the pH detector 25 is detachably arranged on the side of the rectangular plate. On the inner side, the outer side of the mixing drum 21 is fixedly provided with a convex block at the position close to the other three sides of the rectangular hole, the convex block is provided with a groove, and the inner side of the rectangular plate is provided with a 3/4 circle convex ring, so The convex ring is matched with the groove, a locking hole is provided on the convex ring, and a locking catch is provided on the convex block, and the locking hole is matched with the locking catch. The setting of the supporting structure ensures the airtightness and at the same time, the PH test meter 25 can be disassembled to prevent it.

Example 2

Usually, we use a turbo foamer to prepare carbon dioxide water-based foam, and manually mix the cement slurry and carbon dioxide water-based foam by manual methods. The foam prepared by this method is not uniform and stable, and is easily broken. At the same time, the contact between the cement slurry and the foam is not sufficient during mixing and stirring. The invention improves the foaming and mixing equipment for foaming and stirring, and the quality of the prepared foam is improved. However, since the cement slurry cannot be fed into the mixer synchronously when the foam enters the mixer, there is no formula for quantitative calculation, which leads to a large amount of material. waste and excessive wear and tear of equipment. Therefore, the device is further improved, and the raw materials required for the calculation formula are obtained. The whole process of the improved work is as follows:

Step A: select foaming agent tea saponin, the amount of tea saponin is 4g/L, foam stabilizer lauryl, the amount of lauryl is 5g/L, thickener is sodium polyacrylate, polyacrylic acid The amount of sodium is 2g/L to prepare the foaming liquid, the temperature of the fixed foaming liquid is 25 degrees Celsius, and carbon dioxide gas is introduced to prepare a small amount of foam, and the foaming ratio Y of the foaming liquid is calculated accordingly. The prepared foam is mixed and stirred with cement slurry according to the foam-to-slurry ratio of 5:1 to obtain foamed cement slurry, and its density Z is obtained by measurement.

Step B: Determine the amount X of the foamed cement slurry required for the experiment, calculate the amount of foam required for stirring according to the density Z of the foamed cement slurry obtained in the experiment in the previous step A, and the foaming slurry ratio is 5:1, and select the foaming agent tea soap The amount of tea saponin is 4g/L, the amount of foam stabilizer dodecyl and dodecyl is 5g/L, the thickener is sodium polyacrylate, and the amount of sodium polyacrylate is 2g/L. The foaming ratio of the foaming liquid obtained according to step A is Y, according to which the foaming agent diluent is made quantitatively, the movable baffle at the bottom of the flask 6 is opened, and it is passed into the flask 6, the baffle is closed, the valve is closed, and the constant temperature heating is turned on. to keep the temperature constant at 25 degrees Celsius.

Step C: The gas filled in the gas cylinder 1 should be inert. In this experiment, in order to explore the various properties of carbon dioxide foamed cement slurry, carbon dioxide is selected as the gas used for foaming, the corresponding gas cylinder is obtained, and the air pressure controller is adjusted. , the control air pressure is 0.2kpa, and the valve is closed.

Step D: the gas inlet pipe 4 is connected with the T-shaped tee pipe 5, the gas inlet pipe 4 is connected with the gas cylinder; the foam chamber 10 is connected with the branch pipe of the T-shaped tee pipe 5, and the other one of the T-shaped tee pipe 5 is connected The branch pipe is connected with the flask 6;

Step E: The volume of each foam chamber 10 is different. According to the previous step B, the amount of foam required for this experiment can be known. According to this, a foam chamber with a suitable volume is selected for installation, and the piston on the left side of the foam chamber is pulled to the far left. side.

Step F: Open the valves of the gas cylinder and the flask 6 at the same time, open the movable baffle at the bottom of the foam chamber, close the valve at the foam inlet pipe, control the flow rate of the gas and liquid, and start foaming.

Step G: The diluted foaming agent solution and a certain gas at a certain pressure enter the lower part of the foaming cylinder, and the foam gradually rises in the foaming cylinder due to the action of the porous medium 11 and the filler 12, and the baffle at the bottom of the foam chamber is opened.

Step H: As the porosity gradually increases, the pore size of the foam becomes larger and uniform.

Step I: To obtain a fine, stable, uniform water-based foam, close the baffle at the bottom of the foam chamber so that the foam is stored inside the foam chamber. At this point, the foaming process is over, we get the carbon dioxide water-based foam required for the experiment and store it inside the foam chamber, and the cement slurry is stirred below, and it is mixed into it synchronously with the foam.

Step J: The amount X of the foamed cement slurry required for the experiment was determined in the previous step B, through the foaming slurry ratio of 5:1 and the water-to-cement ratio of 1:2.4 and the proportion of various cementitious materials - light magnesium oxide 15% , 25% fly ash, 60% cement, calculate the amount of water, cement, light magnesia and fly ash required for mixing and prepare them.

Step K: mixing water, cement and other materials to obtain cement slurry.

Step L: Open the valve at the foam inlet pipe, slowly push the piston according to the experimental requirements, so that the foam enters the mixer, at the same time pour the previously prepared cement slurry into the slurry inlet of the mixer, and turn on the motor.

Step M: The motor rotates the hollow screw clockwise, so that the mixing drum rotates counterclockwise, and the foam is discharged from the foaming hole and moves forward together with the cement slurry; the helical inner shaft blade and the rectangular outer shaft blade are simultaneously stirred and mixed in opposite directions. .

Step N: Read the density of the foamed grout according to the reading of the tuning fork density meter

Step 0: Turn on the side wall of the mixer at the pH detector, take out the pH test paper fixed on the side wall, and read the pH value of the foamed cement slurry according to the color of the test paper.

Step P: The prepared foamed cement slurry is discharged from the slurry outlet, and the motor is turned off.

Step Q: Obtain the desired foamed cement slurry.

Calculate the amount of water, cement, fly ash, light magnesium oxide and foaming liquid required for this experiment by the following formula:

C=0.426X×Z

D=0.1775X×Z

E=0.1065X×Z

Among them, X is the volume of the foamed cement slurry required before the experiment, Y is the foaming ratio of the foaming liquid, Z is the density of the foamed cement slurry read out according to the density meter in the previous experiment, and K is the density of the foaming liquid , A is the volume of foaming liquid required for the experiment, B is the mass of water required for mixing cement, C is the required quality of cement, D is the required mass of fly ash, and E is the required quality of light magnesia.

The water-based foam prepared by the invention has a uniform foam structure, a higher foaming multiple and a certain stabilization time.

Based on the two most important performance indicators of compressive strength and density, after optimizing the proportion of each material component, the mechanical properties of carbon dioxide foam composite cement slurry were measured, including stone rate, water separation rate, setting time and fluidity, and the performance of foamed cement slurry was compared. Standard analysis of carbon dioxide foam cement slurry grouting applicability, setting time is measured by a typical Vicat instrument, and fluidity is measured by a truncated cone die method. The test results are shown in the following table:

Table 1 Determination table of mechanical properties of foam composite cement slurry

It can be seen from the table that the compressive strength of carbon dioxide foamed cement stone body modified by external admixtures far exceeds the strength standard of foamed cement and is higher than that of ordinary cement stone body, and the density, stone rate and water separation rate all meet the requirements of foamed cement slurry ; The initial setting time of foamed cement is 146min and the final setting time is 413min, which meets the setting time requirements, which is longer than the initial setting time of ordinary cement slurry of 45min and the final setting time of 390min. The reason is that a large amount of free water in the slurry is stored in the liquid film of the foam system. , the free water will separate out after the foam dissipates, which prolongs the hydration process. At the same time, the existence of the foam makes the sample more loose and porous and prolongs the movement path of the water; The fluidity increased by about 20% from 16 to 18 cm, indicating that the incorporation of water-based foam increased the fluidity of the slurry material.

The embodiment of the present invention provides a foaming and mixing equipment, which prepares carbon dioxide water-based foam through a foamer, and mixes and stirs the carbon dioxide water-based foam and cement slurry through the mixer, and finally obtains carbon dioxide foamed cement slurry for use in On-site engineering, reducing carbon dioxide emissions and providing new lightweight and high-strength materials for on-site construction, low cost and environmentally friendly.

In general, the mixing equipment has the characteristics of less foam rupture, simple structure, uniform mixing and continuous production of large-flow foamed cement slurry. At the same time, the equipment enables the foam and cement slurry to enter the mixer at the same time through the storage function of the foam chamber for mixing. , less material loss and equipment wear.

In actual engineering, the quality of the foamed cement slurry produced mainly depends on two core components, the foamer and the mixer. The present invention redesigns the porous foamer, which is less designed in the prior art. A two-way stirring mixer is designed, which is more suitable for practical projects;

Through the design of the foamer and the mixer, the application can prepare uniform, fine and stable carbon dioxide water-based foam and foam cement slurry with low foam breaking rate, large contact area and uniform mixing. At the same time, the equipment is simple in structure, low in cost, easy to manufacture and has high reliability, and the foamed cement slurry produced can meet the requirements of on-site construction.

Claims (10)

1. The apparatus for preparing water-based foam and mixing it with cement slurry as claimed in claim 1, wherein:

comprises a gas cylinder (1), a flask (6), a foam chamber (10) and a mixing drum (21), inert gas is filled in the gas bottle (1), the gas outlet of the gas bottle (1) is communicated with a gas inlet pipe (4) and a T-shaped three-way pipe (5) in sequence, the other two ends of the T-shaped three-way pipe (5) are respectively communicated with a foaming liquid inlet pipe (9) at the opening of the flask (6) and an opening pipeline at the left lower end of the foam chamber (10), foaming liquid is filled in the flask (6), a constant temperature heater (7) is arranged on the flask (6), a plurality of layers of porous media (11) with gradually increasing porosity are arranged in the foam chamber (10), fillers (12) are arranged between the adjacent layers of porous media (11), the bottom of the foam chamber (10) is provided with a discharge pipe (13), the middle upper end of the foam chamber (10) is provided with a foam outlet pipe (14), a gas cylinder valve (3) is arranged at the gas outlet of the gas cylinder (1), a flask valve (8) is arranged at the outlet of the flask (6), a foam outlet pipe valve (15) is arranged at the foam outlet pipe (14), the foam outlet pipe (14) is communicated with the mixing drum (21), the upper end of the mixing drum (21) is provided with a grout inlet (17) for inputting cement grout, the lower end of the mixing drum (21) is provided with a slurry outlet (24).

2. The apparatus for preparing water-based foam and mixing it with cement slurry as claimed in claim 1, wherein:

the churn (21) is transversely placed, be equipped with the cavity hob (22) of transversely placing in churn (21), churn (21) with cavity hob (22) all link to each other with the rotation axis of bearing (16), bearing (16) are through motor (26) power supply, foam outlet pipe (14) stretch into in churn (21), foam outlet pipe (14) with cavity hob (22) communicate with each other, evenly set up out bubble round hole (19) on cavity hob (22).

3. An apparatus for preparing water-based foam and mixing it with cement slurry according to claim 2, wherein:

the bearing (16) comprises an inner rotating shaft and an outer rotating shaft which rotate reversely, the inner rotating shaft is connected with the hollow screw rod (22), the outer rotating shaft is connected with the mixing drum (21), a plurality of inner shaft blades (18) are arranged on the outer wall of the hollow screw rod (22), and a plurality of outer shaft blades (20) are arranged on the inner wall of the mixing drum (21).

4. A device for preparing water-based foam and mixing it with cement slurry according to claim 3, characterized in that:

the inner shaft blades (18) are spiral stainless steel blades, and the outer shaft blades (20) are rectangular stainless steel blades.

5. A device suitable for preparing water-based foam and mixing it with cement slurry, according to claim 3, characterized in that:

the porous medium (11) is a plurality of layers of steel wire meshes, and the filler (12) is steel wool and is uniformly filled between the steel wire meshes of adjacent layers.

6. An apparatus for preparing water-based foam and mixing it with cement slurry according to claim 4, wherein: the upper right portion of churn (21) is equipped with density detection meter (23) and PH detection meter (25), be equipped with air pressure controller (2) on gas cylinder (1).

7. An apparatus for preparing water-based foam and mixing it with cement slurry according to claim 6, wherein:

be equipped with the rectangle hole on churn (21), the outside of churn (21) is close to the position on one side of rectangle hole articulates and is equipped with the rectangular plate, PH detects meter (25) and can dismantle the setting and be in the inboard of rectangular plate, the outside of churn (21) is close to the other trilateral rigidity of rectangular hole is equipped with the lug, the lug is equipped with the recess, the inboard of rectangular plate is equipped with the protruding circle of 3/4 circle, protruding circle with recess looks adaptation, be equipped with the lockhole on the protruding circle, be equipped with the hasp on the lug, the lockhole with hasp looks adaptation.

8. An apparatus for preparing water-based foam and mixing it with cement slurry according to claim 6, wherein:

the reading of the air pressure controller (2) is 0.2kpa, the foaming liquid adopted in the flask (6) comprises 4g/L foaming agent tea saponin, 5g/L foaming stabilizer dodecyl and 2g/L thickening agent sodium polyacrylate, and the temperature of the constant temperature heater (7) is set to be 25 ℃.

9. An apparatus for preparing water-based foam and mixing it with cement slurry according to claim 8, wherein:

the method for preparing the foamed cement slurry comprises the following steps:

step A: introducing inert gas into the foaming liquid to prepare foam, calculating the foaming ratio Y of the foaming liquid, and mixing the prepared foam according to the ratio of 5: mixing and stirring the foamed cement slurry with the foamed cement slurry ratio of 1 to obtain foamed cement slurry for the test, and measuring to obtain the density Z of the foamed cement slurry;

and B: calculating the amount of foam required by the experiment based on the amount X of foam cement paste prepared by the planned experiment and the density Z of the foam cement paste, wherein the foam amount is 0.83X, and preparing foaming liquid according to the amount;

and C: filling inert gas in the gas cylinder (1), closing the gas cylinder valve (3), and adjusting the gas pressure controller (2) to enable the gas pressure in the gas cylinder (1) to be 0.2kpa;

step D: connecting a gas bottle (1) with a gas inlet pipe (4), communicating the gas inlet pipe (4) with a T-shaped three-way pipe (5), communicating the other two branches of the T-shaped three-way pipe (5) with a foaming liquid inlet pipe (9) at the opening of a flask (6) and an opening pipeline at the left lower end of a foam chamber (10) respectively, and closing a flask valve (8);

and E, step E: based on the amount of foam required by the experiment in the step B, selecting a foam chamber (10) with a proper volume to be communicated with the T-shaped three-way pipe (5);

step F: simultaneously opening a gas cylinder valve (3) and a flask valve (8), and closing a foam outlet pipe valve (15) to prepare foam;

step G: under the push of the inert gas pressure, the foam enters the foam chamber (10) and gradually rises, and passes through the porous medium (11) and the filler (12);

step H: with the gradual increase of the porosity, the pore diameter of the foam is larger and uniform;

step I: fine, stable and uniform water-based foam is obtained and stored in the foam chamber (10);

step J: based on the foam slurry ratio of 5:1 and water-to-glue ratio of 1:2.4, 15% of light magnesium oxide, 25% of fly ash and 60% of cement, and calculating and preparing the use amounts of water, cement, light magnesium oxide and fly ash required during mixing and stirring;

step K: mixing and stirring water, cement, light magnesium oxide and fly ash to prepare cement paste;

step L: opening a valve (15) of the foam outlet pipe, and pouring the prepared cement slurry into a slurry inlet (17);

step M: the motor (26) is started, the hollow screw rod (22) rotates clockwise, the mixing drum (21) rotates anticlockwise, and foam is discharged from the foam outlet circular hole (19) and moves forwards in a spiral mode together with cement slurry;

and step N: reading out the density of the foamed cement slurry according to the reading of the density detector (23);

step O: reading the PH value of the foam cement slurry according to a PH detector (25);

step P: discharging the prepared foamed cement slurry from the slurry outlet (24), and closing the motor (26);

and Q: obtaining the required foamed cement slurry.

10. An apparatus for preparing water-based foam and mixing it with cement slurry according to claim 9, wherein:

the calculation formula in the process of preparing the foamed cement slurry is as follows:

C＝0.426X×Z

D＝0.1775X×Z

E＝0.1065X×Z

wherein X is the volume of the foamed cement slurry prepared according to the plan of the experiment, Y is the foaming multiplying power of the foaming liquid, Z is the density of the foamed cement slurry measured by the experiment, K is the density of the foaming liquid, A is the volume of the foaming liquid required by the experiment, B is the mass of water required by stirring cement, C is the mass of the required cement, D is the mass of the required fly ash, and E is the mass of the required light magnesium oxide.

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