CN115157443A

CN115157443A - Device suitable for preparing water-based foam and mixing and stirring water-based foam and cement paste

Info

Publication number: CN115157443A
Application number: CN202210696955.XA
Authority: CN
Inventors: 丰土根; 厉治平; 张箭; 金嘉鑫; 陈子昂
Original assignee: Hohai University HHU
Current assignee: Hohai University HHU
Priority date: 2022-06-20
Filing date: 2022-06-20
Publication date: 2022-10-11
Anticipated expiration: 2042-06-20
Also published as: CN115157443B

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

Device suitable for preparing water-based foam and mixing and stirring water-based foam and cement paste

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 and stirring the water-based foam and cement paste.

Background

The foamed cement slurry has lower permeability and higher strength under the same water-cement ratio condition. The foamed cement slurry with different specific gravity can completely meet the requirements of different working performances such as compressive strength, permeability, fluidity and the like. Foamed cement slurries have been widely used as a new material. Meanwhile, in cement production, a large amount of gas polluting the environment, such as carbon dioxide gas, is generated due to fuel combustion and clinker calcination, and in order to reduce carbon emission in air and protect the environment, the gas is tried to be used for preparing water-based foam, so that light foam cement slurry is prepared, and then the method for preparing foam synchronous grouting slurry from the light foam cement slurry is used, and the effect is achieved. However, most of the water-based foams prepared by the existing foaming equipment do not have a uniform foam structure, the foaming times are high, the stability time is long, the prepared water-based foams cannot meet the quality requirements of engineering, meanwhile, most of the existing mixing equipment is added once during mixing and stirring, the water-based foams and the cement paste are mixed, the foams are easy to break during mixing, the foam breaking rate is high, the contact area of the water-based foams and the cement paste is small, various properties of the foam cement paste obtained by mixing and stirring cannot meet the engineering requirements, manual stirring is often needed for obtaining the foam cement paste with good quality during experiments, meanwhile, the prior art can hardly realize the step synchronization of foaming and mixing and stirring, namely, after foaming is completed, the foams are introduced into a mixer while the cement paste is added so as to ensure that the material loss is less, and the equipment is less worn.

Therefore, a foaming device capable of preparing fine, uniform and stable water-based foam and a mixing device which has a simple structure, less foam breakage during mixing and stirring and large contact area between the foam and cement paste are needed, and the two devices are required to be ensured to be consistent in working steps.

Disclosure of Invention

The technical problem to be solved by the invention is to provide a device suitable for preparing water-based foam and mixing and stirring the water-based foam and cement paste, wherein the device provides gas required by foam preparation through different gas cylinders; providing foaming liquid with constant temperature through a flask; preparing fine, stable and uniform water-based foam through a foaming device; mixing and stirring the prepared water-based foam and cement paste by a mixer to obtain foamed cement paste which is low in foam breaking rate, large in contact area of the foam and the cement paste and capable of meeting engineering requirements in various properties; the foaming and mixing are controlled in pace by the designed working steps. In addition, the device has simple structural design and low cost.

In order to solve the technical problems, the technical scheme adopted by the invention is as follows:

a device suitable for preparing water-based foam and mixing and stirring the water-based foam and cement paste 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 constant temperature heater is arranged on the flask, a plurality of layers of porous media with gradually-increased 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, a gas cylinder valve is arranged at the gas outlet of the gas cylinder, a flask valve is arranged at the outlet of the flask, a foam outlet pipe valve is arranged at the foam outlet pipe, the foam outlet pipe is communicated with the stirring cylinder, a cement paste inlet is arranged at the upper end of the stirring cylinder and a paste outlet is arranged at the lower end of the stirring cylinder.

Further, the churn is transversely placed, be equipped with the cavity hob of transversely placing in the churn, the churn with the cavity hob all links to each other with the rotation axis of bearing, the bearing passes through the motor power supply, the foam outlet pipe stretches into in the churn, the foam outlet pipe with the cavity hob communicates with each other, evenly set up out the bubble round hole on the cavity hob.

Preferably, the bearing comprises an inner rotating shaft and an outer rotating shaft which rotate reversely, the inner rotating shaft is connected with the hollow spiral rod, the outer rotating shaft is connected with the mixing drum, a plurality of inner shaft blades are arranged on the outer wall of the hollow spiral rod, and a plurality of outer shaft blades are arranged on the inner wall of the mixing drum.

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 plurality of layers of steel wire meshes, and the filler is steel wool and is uniformly filled between the steel wire meshes of the adjacent layers.

Further, the upper right portion of churn is equipped with density detector and PH detector, be equipped with the atmospheric pressure controller on the gas cylinder.

Further, be equipped with the rectangle hole on the churn, the outside of churn is close to the position on one side of the rectangle hole is articulated to be equipped with the rectangular plate, the PH gauge can be dismantled and set up the inboard of rectangular plate, the outside of churn 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.

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

Further, 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;

step C: filling inert gas in the gas cylinder, closing a valve of the gas cylinder, and adjusting a gas pressure controller to enable the gas pressure in the gas cylinder to be 0.2kpa;

step D: connecting a gas bottle with a gas inlet pipe, communicating the gas inlet pipe with a T-shaped three-way pipe, communicating the other two branches of the T-shaped three-way pipe 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 respectively, and closing a flask valve;

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

step F: simultaneously opening a gas cylinder valve and a flask valve, and closing a foam outlet pipe valve to prepare foam;

step G: under the push of the inert gas, the foam enters the foam chamber and gradually rises and passes through the porous medium and the filler;

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;

step J: based on the foam slurry ratio of 5:1 and water-glue ratio of 1:2.4, 15% of light magnesium oxide, 25% of fly ash and 60% of cement, and calculating and preparing the dosage 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 of the foam outlet pipe, and pouring the prepared cement slurry into the slurry inlet;

step M: the motor is turned on, the hollow screw rod rotates clockwise, the stirring cylinder rotates anticlockwise, and foam is discharged from the foam discharge circular hole and moves forward spirally together with cement slurry;

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

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

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

step Q: obtaining the required foamed cement slurry.

Preferably, 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 planned to be prepared in the experiment, Y is the foaming multiplying power of the foaming liquid, Z is the density of the foamed cement slurry measured in 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.

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

the technical problem to be solved by the invention is to provide a device suitable for preparing water-based foam and mixing and stirring the water-based foam and cement paste, wherein the device provides gas required by foam preparation through different gas cylinders; providing foaming liquid with constant temperature through a flask; fine, stable and uniform water-based foam is prepared by a foam maker; mixing and stirring the prepared water-based foam and cement paste by a mixer to obtain foamed cement paste which is low in foam breaking rate, large in contact area of the foam and the cement paste and capable of meeting engineering requirements in various properties; the foaming and mixing are controlled in pace by the designed working steps. In addition, the device has the advantages of simple structural design and low cost.

Drawings

FIG. 1 is a schematic view of an apparatus suitable for preparing water-based foam and mixing it with cement slurry according to the present invention;

FIG. 2 is a schematic view of the interior of a foam chamber of the present invention;

FIG. 3 shows the design and measurement principle of the homemade PH meter of the present invention.

The device comprises a 1-gas cylinder, a 2-gas pressure controller, a 3-gas cylinder valve, a 4-gas inlet pipe, a 5-T-shaped tee pipe, a 6-flask, a 7-constant temperature heater, an 8-flask valve, a 9-foaming liquid inlet pipe, a 10-foaming chamber, 11-porous medium, 12-filler, a 13-discharge pipe, a 14-foaming outlet pipe, a 15-foaming outlet pipe valve, a 16-bearing, a 17-pulp inlet, an 18-inner shaft blade, a 19-foaming circular hole, a 20-outer shaft blade, a 21-stirring cylinder, a 22-hollow screw rod, a 23-density detector, a 24-pulp outlet, a 25-PH detector and a 26-motor.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

The embodiment of the invention provides 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 provided with a gas pressure controller 2 and a gas cylinder valve 3; the device for providing foaming liquid is a flask 6, which is provided with a constant temperature heater 7, a movable bottom plate and a flask valve 8; the foaming equipment comprises a gas inlet pipe 4, a foaming liquid inlet pipe 9, a T-shaped three-way pipe 5, a foam chamber and a movable bottom plate 10 thereof, a porous medium 11, a filler 12, a discharge pipe 13, a foam outlet pipe 14 and a foam outlet pipe valve 15; the apparatus supplies a gas raw material for foaming through the gas cylinder 1, controls gas pressure during aeration based on a gas pressure controller 2, controls aeration speed based on a gas cylinder valve 3, introduces gas based on the gas inlet pipe 4, stores foaming liquid based on the flask 6, controls temperature of the foaming liquid based on the constant temperature heater 7, controls opening and closing of the flask 6 based on the movable bottom plate, controls introduction speed of liquid based on the flask valve 8, introduces foaming liquid based on a foaming liquid inlet pipe 9, connects the gas inlet pipe 4, the foaming liquid inlet pipe 9 and the foaming cylinder based on the T-shaped three-way pipe 5, stores prepared water-based foam based on the foam chamber and the movable bottom plate 10 thereof, finely, uniformly and stably prepares foam based on a porous medium 11 and a filler 12, performs the whole foaming process based on the foaming cylinder, discharges diluent which is not sufficiently foamed based on the discharge pipe 13, discharges incompletely foamed liquid based on the discharge pipe 13, introduces foam into a mixer based on the foam outlet pipe 14, and controls introduction time based on the foam outlet pipe valve 15.

As shown in fig. 2, the bottom of the foam chamber 10 is provided with a movable baffle, the foam outlet pipe 14 is provided with a valve, so that foam can be better stored in the foam chamber, the valve is opened after cement slurry is mixed, the foam and the cement slurry can be accurately controlled to be introduced into the mixer, and material loss and equipment abrasion are effectively reduced. The foam chamber 10 has various different volumes, and the foam chamber 10 is detachable, and the foam chamber 10 with different volumes can be accurately selected to be installed in the foam maker according to the amount of foam required by engineering. The left side of the foam chamber 10 is provided with a piston, and the surface of the foam chamber is provided with scales, so that the foam can be accurately pushed into a subsequent mixer by compressing the piston after the valve is opened.

Specifically, the air pressure controller 2 is arranged on the upper left side of the air bottle 1, the air bottle valve 3 is located at an outlet of the air bottle 1, the air bottle 1 is connected with the air inlet pipe 4, the right side of the air inlet pipe 4 is connected with a left end guide port of the T-shaped three-way pipe 5, and the air bottle 1 is filled with needed air based on the air inlet pipe 4. The thermostatic controller 7 is arranged at the outer side 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, the lower part of the foaming liquid inlet pipe 9 is connected with the upper guide port of the T-shaped three-way pipe 5, the right guide port of the T-shaped three-way pipe 5 is connected with the foaming cylinder, and the raw materials are introduced and foamed; the foaming cylinder is placed vertically (the gas-liquid movement direction is opposite to the gravity direction of a steel plate), a discharge pipe 13 is arranged at the lowest part, the filler 12 and the porous medium 11 are arranged inside the foaming cylinder, a foam chamber and a baffle plate 10 of the foaming cylinder are arranged at the top of the foaming cylinder, and the vertically placed gas-liquid flow direction is opposite to the gravity direction, namely, a bubbling effect is introduced, so that the generation of foam is facilitated. The T-shaped three-way pipe 5 is simple in structure, easy to machine and manufacture and low in cost, and can be used for simultaneously introducing gas and foaming liquid into the foaming device to control the quality of obtained foam.

Preferably, the flask 6 is inverted, scales are marked on the side wall of the flask, the introduction of the foaming liquid is easy and convenient, and the volume of the introduced foaming liquid can be accurately controlled.

Furthermore, 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 proportion of foaming liquid adopted in the flask 6 is 4g/L of tea saponin, the proportion of the selected foam stabilizer is 5g/L of dodecyl, the thickening agent is 2g/L of sodium polyacrylate, the temperature is constantly controlled at 25 ℃ by adjusting the constant temperature heater 7, the carbon dioxide gas is provided through the gas cylinder 1, the foaming liquid is provided through the flask 6, and the carbon dioxide gas, the foaming liquid and the foaming liquid are mixed for foaming. The foaming liquid is non-toxic and pollution-free.

Further, the filler 12 is steel wool, and the porous medium 11 is a steel wire mesh. The steel wire mesh is provided with three layers, and the aperture of the steel wire mesh is 0.1mm,0.5mm and 1.0mm from bottom to top respectively. Steel wool is filled between the steel wire meshes. Set up the wire net in the foam chamber 10, it has the steel wool to fill between the wire net, and the porosity crescent of wire net, wire net and steel wool simultaneous action can form the torrent vortex, and along with the crescent of porosity, foam aperture grow and even. The porous medium 11 is made of a steel wire mesh, the filler 12 is made of steel wool, and engineering effectiveness and economic applicability are considered comprehensively.

The mixing device comprises a bearing 16, a pulp inlet 17, an inner shaft blade 18, a bubble outlet circular hole 19, an outer shaft blade 20, a mixing drum 21, a hollow screw rod 22, a density detector 23, a pulp outlet 24, a PH detector 25 and a motor 26. The mixing device controls the mixing drum 21 and the hollow screw rod 22 to rotate through the bearing 16, cement slurry which is not mixed with foam is introduced through the slurry inlet 17, foam produced by the foam generator flows out through the foam outlet circular hole 19, cement slurry and the foam are mixed and stirred through the inner shaft blade 18 and the outer shaft blade 20, the mixing drum 21 and the hollow screw rod 22 rotate to drive the blades to rotate, prepared carbon dioxide foam cement slurry is discharged through the slurry outlet 24, power for driving the mixing drum and the hollow screw to rotate is provided through the motor 26, and the related performance of the foam is measured through the density detector 23 and the PH detector 25.

Specifically, the mixing drum 21 is placed horizontally, the left end of the mixing drum is connected with the foam outlet pipe 14 in the foaming device, the hollow screw rod 22 is located inside the mixing drum and connected with the right end of the foam outlet pipe 14, the foam outlet circular holes 19 are uniformly formed in the hollow screw rod 22, and the right end of the mixing drum 21 is provided with the motor 26. The slurry inlet 17 and the slurry outlet 24 are respectively positioned at the upper left part and the lower right part of the mixing drum. The density detector 23 and the PH detector 25 are respectively disposed inside the mixing drum at the upper part of the rightmost end of the mixing drum.

The inner shaft blade 18 is disposed outside the hollow screw 22, and the outer shaft blade 20 is disposed inside the agitating 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 agitating drum 21. Through motor 26 provides power, through bearing 16 control cavity hob 22 and churn 21 counter rotation drive interior axle blade 18 and outer axle blade 20 and rotate, jet into grout through advancing the mouth 17, make the foam precipitate through going out bubble round hole 19, rotate through interior axle blade 18 and outer axle blade 20 and mix the stirring to grout and foam, discharge gained carbon dioxide foam grout through a grout outlet 24, measure the correlation properties of foam grout prepared through density detector 23 and PH detector 25.

The internal and external bearings respectively control the rotation of the hollow screw rod 22 and the mixing drum 21, and the stability of the device is improved. The motor 26 is adopted to control the hollow screw rod 22 and the mixing drum 21 to rotate, so that the labor consumption is reduced. The center of the pitch of each circle of the helical blade is provided with a foam outlet round hole 19 as a foam outlet, so that the contact area between the foam and cement paste is increased, the foam is uniformly distributed, and the foam breaking rate is reduced. The hollow screw rod 22 and the stirring cylinder 21 rotate in opposite directions, so that the contact area of the foam and the cement paste is increased, and the uniform mixing degree of the foam and the cement paste is improved. The inner shaft blade is spiral, so that the stirring efficiency is obviously improved, the contact area is increased, and the bubble breaking rate is reduced. The blades of the inner shaft and the outer shaft are made of stainless steel materials, so that the possibility of rusting and strength reduction after long-time contact with foams is reduced.

Further, the diameter of the circular foam outlet hole 19 is 1.0mm, so that the foam prepared before can be separated out.

Further, interior axle blade 18 is the spiral, outer axle blade 20 is the rectangle, and the material of adoption is the stainless steel, can increase the stirring area, reduces broken bubble rate, improves stirring efficiency and prevents that the blade is rusted simultaneously, and intensity reduces.

Further, the rotation direction of the agitating drum 21 is counterclockwise, and the rotation direction of the hollow screw 22 is clockwise. The contact area of stirring is increased, and the mixing is more uniform and sufficient.

Further, the density detector 23 is a tuning fork densitometer of the type LDS-2100 tuning fork densitometer, and the density measurement range is 0 to 3g/cm3. And the pH meter adopts a pH test paper to measure the pH value of the foam cement slurry.

As shown in fig. 3, the PH meter 25 may be detachably placed in the agitation tank 21. Preferably, be equipped with the rectangle hole on the churn 21, the outside of churn 21 is close to the position on one side of the rectangle hole is articulated to be equipped with the rectangular plate, PH detector 25 can be dismantled and set up 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. The arrangement of the matching structure ensures the sealing and can be detached to prevent the PH tester 25.

Example 2

Generally, we prepared carbon dioxide water-based foam using a turbine-type foamer and manually mixed cement slurry and carbon dioxide water-based foam using a manual method. The foam prepared by the method is not uniform and stable enough and is easy to break, meanwhile, the cement paste and the foam are not sufficiently contacted during mixing and stirring, the strength of the prepared test block is low, and the foam in the cement paste breaks more. The invention improves the manufacturing foaming and mixing equipment for foaming and stirring, improves the quality of the prepared foam, but has no quantitative calculation formula because cement slurry is not synchronously introduced when the foam enters the mixer, thus causing the waste of a large amount of materials and the excessive abrasion of the equipment. Thereby further improving the device and obtaining a calculation formula to calculate the required raw materials. The improved whole working process is as follows:

step A, selecting a foaming agent tea saponin, wherein the amount of the tea saponin is 4g/L, a foam stabilizer is dodecyl, the amount of dodecyl is 5g/L, a thickening agent is sodium polyacrylate, the amount of the sodium polyacrylate is 2g/L, preparing a foaming solution, fixing the temperature of the foaming solution to be 25 ℃, introducing carbon dioxide gas to prepare a small amount of foam, and calculating the foaming ratio Y of the foaming solution according to the foaming ratio. The finished foam was prepared according to 5: mixing the foamed cement slurry with the cement slurry according to the foam slurry ratio of 1, stirring to obtain foamed cement slurry, and measuring to obtain the density Z of the foamed cement slurry.

And B, step B: determining the dosage X of the foamed cement slurry required by the experiment, and according to the density Z of the foamed cement slurry obtained in the experiment in the previous step A, the foam-slurry ratio is 5:1, calculating the amount of foam required by stirring, selecting a foaming agent, namely tea saponin, wherein the amount of the tea saponin is 4g/L, a foam stabilizer, namely dodecyl, the amount of dodecyl is 5g/L, a thickening agent is sodium polyacrylate, and the amount of the sodium polyacrylate is 2g/L. And D, obtaining the foaming multiplying power of the foaming liquid Y according to the step A, quantitatively preparing a foaming agent diluent according to the foaming multiplying power, opening a movable baffle at the bottom of the flask 6, introducing the movable baffle into the flask 6, closing the baffle, closing a valve, and opening a constant temperature heater to ensure that the temperature is constant at 25 ℃.

And C: the gas filled in the gas cylinder 1 should be inert, in order to explore various properties of the carbon dioxide foam cement slurry in the experiment, carbon dioxide is selected as the gas used in foaming, the corresponding gas cylinder is obtained, a gas pressure controller is adjusted, the gas pressure is controlled to be 0.2kpa, and a valve is closed.

Step D: the gas inlet pipe 4 is connected with the T-shaped three-way pipe 5, and the gas inlet pipe 4 is connected with the gas bottle; the foam chamber 10 is connected with a branch pipe of the T-shaped three-way pipe 5, and the other branch pipe of the T-shaped three-way pipe 5 is connected with the flask 6;

and E, step E: the volume of each foam chamber 10 is different, and the amount of foam required in this experiment is known from the previous step B, and accordingly, the foam chamber with the appropriate volume is selected and installed, and the piston on the left side of the foam chamber is pulled to the leftmost side.

Step F: simultaneously, the valves of the gas cylinder and the flask 6 are opened, the movable baffle at the bottom of the foam chamber is opened, the valve at the foam inlet pipe is closed, the flow rate of gas and liquid is controlled, and foaming is started.

G: the diluted foaming agent solution and certain gas with certain pressure enter the lower part of the foaming cylinder, and the foam gradually rises in the foaming cylinder under the action of the porous medium 11 and the filler 12, so that the baffle at the bottom of the foam chamber is opened.

Step H: with increasing porosity, the foam pore size becomes larger and uniform.

Step I: fine, stable, uniform water-based foam is obtained, and the baffle at the bottom of the foam chamber is closed, so that the foam is stored inside the foam chamber. At this point, the foaming process is over and we have the carbon dioxide water-based foam needed for the experiment and stored it inside the foam chamber, where the stirring of the cement slurry is performed and it is fed into the mixing chamber in synchronism with the foam.

Step J: the amount X of foamed cement slurry required for the experiment was determined in the previous step B by a foam-to-slurry ratio of 5:1 and water-to-glue ratio of 1:2.4 and the proportion of various cementing materials, namely 15 percent of light magnesium oxide, 25 percent of fly ash and 60 percent of cement, and calculating and preparing the dosage of water, cement, light magnesium oxide and fly ash required during mixing and stirring.

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

Step L: the valve at the foam inlet pipe is opened, the piston is pushed slowly according to the experimental requirements, so that the foam enters the mixer, simultaneously the prepared cement slurry is poured into the slurry inlet of the mixer, and the motor is turned on.

Step M: the motor enables the hollow screw rod to rotate clockwise, the stirring cylinder rotates anticlockwise, and foam is discharged from the foam outlet circular hole and moves forward along with cement slurry in a spiral mode; the helical inner shaft blade and the rectangular outer shaft blade are simultaneously stirred and mixed in opposite directions.

And step N: reading out the density of the foamed cement slurry according to the reading of a tuning fork densimeter

Step O: and turning over the side wall of the mixer at the PH detector, taking out the PH test paper fixed on the side wall, and reading out the PH value of the foamed cement slurry according to the color of the test paper.

Step P: discharging the prepared foamed cement slurry from the slurry outlet, and closing the motor.

And Q: obtaining the required foamed cement slurry.

The amounts of water, cement, fly ash, light magnesium oxide and foaming liquid required by the experiment are calculated by the following calculation formula:

C＝0.426X×Z

D＝0.1775X×Z

E＝0.1065X×Z

wherein X is the volume of the required foamed cement slurry determined before the experiment, Y is the foaming multiplying power of the foaming liquid, Z is the density of the foamed cement slurry read out by a densimeter in the previous 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 for stirring the 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.

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

After the material component proportions are preferably selected based on two most important performance indexes of compressive strength and density, the expansion mechanical properties of the carbon dioxide foam composite cement slurry are measured, wherein the expansion mechanical properties comprise calculus rate, water precipitation rate, setting time and fluidity, the applicability of the carbon dioxide foam cement slurry grouting is analyzed by comparing the performance standards of the foam cement slurry, the setting time is measured by adopting a typical Vicat instrument, the fluidity is measured by adopting a truncated cone circular mold method, and the test results are shown in the following table:

TABLE 1 foam composite cement slurry mechanical property testing table

As can be seen from the table, the compressive strength of the carbon dioxide foam cement concretion body modified by the external additive far exceeds the foam cement strength standard and is higher than that of the common cement concretion body, and the density, the concretion rate and the water precipitation rate all meet the requirements of foam cement slurry; the initial setting time of the foam cement is 146min, the final setting time is 413min, the requirement on the setting time is met, and the initial setting time is 45min and the final setting time is longer than the initial setting time and the final setting time of ordinary cement slurry, because a large amount of free water in the slurry is stored in a liquid film of a foam system, the free water is separated out after the foam is dissipated, the hydration process is prolonged, and meanwhile, the existence of the foam enables a sample to be more loose and porous, and the movement path of water is prolonged; the average value of the fluidity is 21cm, the fluidity requirement of the foam cement is met, the fluidity of the foam cement is increased by about 20 percent compared with the fluidity of the ordinary cement slurry of 16-18 cm, and the water-based foam is added to increase the fluidity of the slurry material.

The embodiment of the invention provides foaming and mixing stirring equipment, which is characterized in that carbon dioxide water-based foam is prepared through a foaming device, the carbon dioxide water-based foam and cement slurry are mixed and stirred through a mixer, and finally the obtained carbon dioxide foam cement slurry is used for site engineering, so that the emission of carbon dioxide is reduced, a light high-strength novel material is provided for site construction, the cost is low, and the environment is friendly.

Generally, this equipment that mixes has the foam and breaks less, simple structure, and the misce bene just can the continuous production large-traffic foam grout's characteristics, and this equipment makes foam and grout can get into the blender simultaneously and stir through the storage function of foam cavity simultaneously, has less the wearing and tearing of loss and the equipment of material.

In practical engineering, the effect of the generated foamed cement slurry is mainly determined by two core components, a foaming device and a mixer, the invention redesigns the pore type foaming device, and the design of the prior art is less in the aspect. A bidirectional stirring type mixer is designed, which is more suitable for practical engineering;

by the design of the foam maker and the mixer, the foam cement slurry which is uniform, fine and stable in carbon dioxide water-based foam, low in foam breaking rate, large in contact area and uniform in mixing can be prepared. Meanwhile, the equipment has the advantages of simple structure, low cost, easy processing and manufacturing and high reliability, and the generated foam cement slurry can meet the requirements of site construction.

Claims

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:

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 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 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.