A VRH-CO2 method intelligent hardening sodium silicate sand testing device

Abstract

The present application belongs to the technical field of casting, and particularly relates to a VRH-CO2 method intelligent hardening sodium silicate sand test device. The present application comprises a CO2 gas source with a pressure reducing valve group, a heater, a vacuum pump, a vacuum chamber and a CO2 recovery buffer tank; the CO2 gas source with the pressure reducing valve group is connected with the vacuum chamber through a pressure reducer, a manual air inlet valve, the heater, a CO2 inlet electromagnetic valve and a CO2 flow meter; the vacuum chamber is connected with the vacuum pump, a CO2 recovery electromagnetic valve and the CO2 recovery buffer tank; the CO2 recovery buffer tank is connected with the vacuum chamber through a CO2 inlet electromagnetic valve, a check valve and a CO2 flow meter; a MCGS device is connected with the signals of the devices of the second, third and fourth parts, and can control the flow meter, the pressure reducer and the recovery electromagnetic valve to adjust the inlet CO2, so that the CO2 is fully reacted with sodium silicate and the reaction efficiency is improved; the used CO2 is recycled and utilized, and the whole reaction process can be intelligently and real-timely monitored; the present application has a simple structure, reliable operation and low damage, can improve the CO2 and sodium silicate reaction rate, and reduce the sodium silicate addition amount and carbon emission.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of casting, and particularly relates to a VRH-CO2 method intelligent hardening sodium silicate sand test device. BACKGROUND

[0002] The key of the CO2 sodium silicate sand hardening process lies in the hardening behavior of CO2 gas on the sodium silicate binder. Years of practice show that the CO2 sodium silicate sand has low strength, poor storage property and is easy to overblow, mainly because the CO2 gas is not effectively controlled. Therefore, the vacuum replacing hardening method (VRH), pulse blowing method, microwave hardening and hot air blowing method are developed. The VRH-CO2 method has the advantages of high compactness of the mold and good surface quality of the mold, and the mold produced by the method has high surface quality and good mechanical properties.

[0003] The VRH hardening method can effectively control the CO2 blowing hardening process. However, in actual production, there are problems such as unstable production, difficult process control and difficult mold stripping.

[0004] Therefore, it is necessary to prepare a test simulation device to study the influence law of process parameters on the molding strength. SUMMARY

[0005] The application aims to provide a VRH-CO2 method intelligent hardening sodium silicate sand test device, solve the problem of CO2 waste in the VRH experiment, reduce the use amount of sodium silicate, improve the CO2 and sodium silicate reaction rate, and ensure the uniformity of the sand mold hardening.

[0006] To achieve the above technical purposes and effects, the application is implemented by the following technical scheme:

[0007] The application provides a VRH-CO2 method intelligent hardening sodium silicate sand test device, which comprises:

[0008] The first part comprises a CO2 gas source and a first pressure reducer, and the first pressure reducer can preliminarily reduce the CO2 in the CO2 gas source;

[0009] The second part comprises a manual air inlet valve, a second pressure reducer, a 1Mpa pressure sensor A, a throttle valve, a CO2 inlet electromagnetic valve A, a CO2 flowmeter, a gas heater and an MCGS device, the manual air inlet valve, the second pressure reducer, the 1Mpa pressure sensor A, the throttle valve, the CO2 inlet electromagnetic valve A, the CO2 flowmeter and the gas heater are sequentially connected, and the second pressure reducer, the CO2 inlet electromagnetic valve A, the CO2 flowmeter and the gas heater are respectively signal-connected with the MCGS device;

[0010] The third part includes a VRH vacuum working chamber, an upper cover, a 0-100℃ temperature transmitter, a 0-100Kpa pressure sensor, a 0-100% CO2 gas sensor, a third pressure reducer, a manual vent valve, a vent solenoid valve and a vacuum pump, wherein the VRH vacuum working chamber, the third pressure reducer, the manual vent valve, the vent solenoid valve and the vacuum pump are sequentially connected, the 0-100% CO2 gas sensor is installed on the outer barrel wall of the VRH vacuum working chamber, and the 0-100℃ temperature transmitter and the 0-100Kpa pressure sensor are installed on the upper cover, and instrument data can be observed at any time during the experiment.

[0011] The fourth part includes a vent solenoid valve, a CO2 recovery solenoid valve, a flowmeter, a 1Mpa pressure sensor B, a CO2 recovery buffer tank and a CO2 inlet solenoid valve B, wherein the vent solenoid valve is installed above the CO2 recovery solenoid valve, and the CO2 recovery solenoid valve, the flowmeter, the 1Mpa pressure sensor B, the CO2 recovery buffer tank and the CO2 inlet solenoid valve B are sequentially connected.

[0012] Further, in the VRH-CO2 method intelligent hardening sodium silicate sand test device, the MCGS device is connected with the 0-100℃ temperature transmitter, the 0-100Kpa pressure sensor and the 0-100% CO2 gas sensor.

[0013] Further, in the VRH-CO2 method intelligent hardening sodium silicate sand test device, the upper cover is placed above the VRH vacuum working chamber during the experiment, and the sand mold is taken out by removing the upper cover after the experiment.

[0014] Further, in the VRH-CO2 method intelligent hardening sodium silicate sand test device, the MCGS device is connected with the CO2 recovery solenoid valve, the flowmeter, the 1Mpa pressure sensor B and the CO2 inlet solenoid valve B.

[0015] Further, in the VRH-CO2 method intelligent hardening sodium silicate sand test device, the first pressure reducer of the first part is connected with the manual inlet valve of the second part, the manual inlet valve of the second part is connected with the VRH vacuum working chamber of the third part, the recovered CO2 can be introduced into the VRH vacuum working chamber of the third part for recycling during the experiment, the vacuum pump of the third part is connected with the CO2 recovery solenoid valve of the fourth part, and the CO2 inlet solenoid valve B of the fourth part is connected with the CO2 flowmeter of the second part.

[0016] Further, in the VRH-CO2 method intelligent hardening sodium silicate sand test device, the MCGS device can set the introduced CO2 through the second pressure reducer, the 1Mpa pressure sensor A and the CO2 flowmeter.

[0017] Further, in the above-mentioned VRH-CO2 method intelligent hardening sodium silicate sand test device, the MCGS device can monitor the reaction process of CO2 and sodium silicate in the VRH vacuum working chamber in real time through a 0-100℃ temperature transmitter, a 0-100Kpa pressure sensor and a 0-100% CO2 gas sensor.

[0018] Further, in the above-mentioned VRH-CO2 method intelligent hardening sodium silicate sand test device, the MCGS device can monitor the CO2 concentration through a flowmeter and a 1Mpa pressure sensor B, judge whether it needs to be recovered, and if it needs to be recovered, control the CO2 recovery electromagnetic valve to open, and if it does not need to be recovered, control the venting electromagnetic valve to open; when the CO2 recovery buffer tank is full, control the CO2 inlet electromagnetic valve B to open, so that the recovered CO2 can be reused.

[0019] The application also provides a CO2 blowing hardening and CO2 recovery process for sodium silicate sand molds, which is realized based on the above-mentioned VRH-CO2 method intelligent hardening sodium silicate sand test device and includes the following steps.

[0020] S1, put sodium silicate and raw sand into a mixer to mix thoroughly; after mixing, press the sand into a mold to make it compact, and obtain a sand mold sample after processing; and place the sand mold sample and the mold in a VRH vacuum working chamber, and place an upper cover on the vacuum tank.

[0021] S2, set the pressure in the VRH vacuum working chamber, the CO2 pressure, the concentration value, the temperature, the aeration time, the reaction time and the specified recovery CO2 pressure value and concentration value on the MCGS device screen, and click start.

[0022] S3, the vacuum pump first extracts air in the vacuum tank to reach the set pressure, the CO2 tank and the pressure reducing valve group first reduce the pressure of the input CO2 through a pressure reducer, then reduce the flow through a flowmeter, and finally change the temperature through a heater to deliver the CO2 to the VRH vacuum working chamber; after the aeration time is reached, the CO2 aeration valve is closed, and the CO2 and the sodium silicate sand mold are placed for reaction; after the reaction time is reached, the vacuum pump extracts the CO2 in the VRH vacuum working chamber.

[0023] S4, the reacted CO2 passes through the flowmeter and the 1Mpa pressure sensor; when the CO2 concentration reaches the recovery standard, the MCGS device controls the CO2 recovery electromagnetic valve to open, and the CO2 enters the CO2 recovery buffer tank; if the concentration does not reach the specified concentration, the MCGS device controls the venting electromagnetic valve to open, and the CO2 enters the air; at this time, the manual venting valve can be opened to destroy the vacuum state; after the pressure in the VRH vacuum working chamber on the MCGS device screen returns to 0, the upper cover is opened, the mold is taken out, and the sodium silicate sand mold is obtained.

[0024] Further, in step S1, the modulus of the water glass solution is 2-5, the water glass solution is added in an amount of 2.5-5% of the mass of the raw sand, and the mixing time of the water glass and the raw sand is 1-2 min.

[0025] In step S2, the MCGS device sets the vacuum extraction range to be-80-0 Kpa, the aeration time to be 10 s-2 min, the hardening reaction time to be 10 s-2 min, and the heating temperature to be 20-80 DEG C.

[0026] The present application has the following advantages:

[0027] 1. The present application provides an intelligent VRH-CO2 method intelligent hardening water glass sand device system, which controls the CO2 entering through the MCGS control pressure reducer, gas heater and flowmeter, so that it can reach the most suitable value before entering the vacuum chamber, and the MCGS and the 0-100% CO2 gas sensor, 0-100 DEG C temperature transmitter and 0-100 Kpa pressure sensor of the vacuum chamber can monitor the reaction process of CO2 and water glass in real time, the whole experiment process can be observed in real time on the MCGS device screen, and the experimental values can also be saved, which is convenient for recording and saving. Prevent CO2 from blowing too much, and the quality of the sand mold is affected. Reduce the amount of water glass added, and make it easier to reuse old sand.

[0028] 2. The present application provides an intelligent VRH-CO2 method intelligent hardening water glass sand device system, which is connected with the CO2 recovery electromagnetic valve, flowmeter, 1Mpa pressure sensor and emptying electromagnetic valve before the CO2 recovery tank, when the CO2 from the vacuum chamber meets a certain concentration, it will enter the CO2 recovery tank, if it does not meet the specified concentration, it will directly enter the air through the emptying electromagnetic valve; and the CO2 inlet electromagnetic valve after the CO2 recovery tank is connected, when the recovery tank is full, the inlet electromagnetic valve will be opened to make the recovered CO2 reusable, and the aeration amount of the CO2 cylinder is intelligently reduced according to the concentration of the CO2 entering. The used CO2 is recycled and reused, and a large amount of CO2 generated during the production process of the manufacturer can also be collected and used in the manufacture of VRH-CO2 method water glass sand, which is economical and efficient, and effectively controls environmental pollution.

[0029] Of course, any product implementing the present application does not necessarily need to achieve all the above advantages at the same time. BRIEF DESCRIPTION OF DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiment description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creating laborious work.

[0031] Figure 1 Figure 1 is a schematic diagram of the composition of a VRH-CO2 method intelligent hardening sodium silicate sand test device;

[0032] Figure 2 Figure 2 is a CO2 sodium silicate sand curing diagram. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0034] The present application provides a VRH-CO2 method intelligent hardening sodium silicate sand test device, comprising:

[0035] The first part comprises a CO2 gas source 1-1 and a first pressure reducer 1-2, the first pressure reducer 1-2 can preliminarily reduce the CO2 in the CO2 gas source 1-1, and the CO2 gas source 1-1 and the first pressure reducer 1-2 jointly constitute a CO2 gas source with a pressure reducing valve group.

[0036] The second part comprises a manual air inlet valve 2-1, a second pressure reducer 2-2, a 1Mpa pressure sensor A2-3, a throttle valve 2-4, a CO2 inlet electromagnetic valve A2-5, a CO2 flowmeter 2-6, a gas heater 2-7 and a MCGS device 2-8, the manual air inlet valve 2-1, the second pressure reducer 2-2, the 1Mpa pressure sensor A2-3, the throttle valve 2-4, the CO2 inlet electromagnetic valve A2-5, the CO2 flowmeter 2-6 and the gas heater 2-7 are connected in sequence, and the second pressure reducer 2-2, the CO2 inlet electromagnetic valve A2-5, the CO2 flowmeter 2-6 and the gas heater 2-7 are respectively signal-connected with the MCGS device 2-8.

[0037] The third part comprises a VRH vacuum working chamber 3-1, an upper cover 3-2, a 0-100℃ temperature transmitter 3-3, a 0-100Kpa pressure sensor 3-4, a 0-100% CO2 gas sensor 3-5, a third pressure reducer 3-6, a manual vent valve 3-7, a vent electromagnetic valve 3-8 and a vacuum pump 3-9, the VRH vacuum working chamber 3-1, the third pressure reducer 3-6, the manual vent valve 3-7, the vent electromagnetic valve 3-8 and the vacuum pump 3-9 are connected in sequence, the 0-100% CO2 gas sensor 3-5 is installed on the outer barrel wall of the VRH vacuum working chamber 3-1, the 0-100℃ temperature transmitter 3-3 and the 0-100Kpa pressure sensor 3-4 are installed on the upper cover 3-2, and the instrument data in the reaction process can be monitored in real time.

[0038] The fourth part comprises a vent electromagnetic valve 4-1, a CO2 recovery electromagnetic valve 4-2, a flowmeter 4-3, a 1Mpa pressure sensor B4-4, a CO2 recovery buffer tank 4-5 and a CO2 inlet electromagnetic valve B4-6, the vent electromagnetic valve 4-1 is installed above the CO2 recovery electromagnetic valve 4-2, and the CO2 recovery electromagnetic valve 4-2, the flowmeter 4-3, the 1Mpa pressure sensor B4-4, the CO2 recovery buffer tank 4-5 and the CO2 inlet electromagnetic valve B4-6 are sequentially connected.

[0039] In the application, the MCGS device 2-8 is connected with a 0-100 DEG C temperature transmitter 3-3, a 0-100 Kpa pressure sensor 3-4 and a 0-100 % CO2 gas sensor 3-5.

[0040] In the application, the upper cover 3-2 is placed above the VRH vacuum working chamber 3-1 during the experiment, and the sand mold is taken out by removing the upper cover 3-2 after the experiment.

[0041] In the application, the MCGS device 2-8 is connected with the CO2 recovery electromagnetic valve 4-2, the flowmeter 4-3, the 1Mpa pressure sensor B4-4 and the CO2 inlet electromagnetic valve B4-6.

[0042] In the application, the first pressure reducer 1-2 of the first part is connected with the manual inlet valve 2-1 of the second part, the manual inlet valve 2-1 of the second part is connected with the VRH vacuum working chamber 3-1 of the third part, the recovered CO2 can be introduced into the VRH vacuum working chamber 3-1 of the third part for recycling during the experiment, the vacuum pump 3-9 of the third part is connected with the CO2 recovery electromagnetic valve 4-2 of the fourth part, and the CO2 inlet electromagnetic valve B4-6 of the fourth part is connected with the CO2 flowmeter 2-6 of the second part.

[0043] In the application, the MCGS device 2-8 can set the introduced CO2 through the second pressure reducer 2-2, the 1Mpa pressure sensor A2-3 and the CO2 flowmeter 2-6.

[0044] In the application, the MCGS device 2-8 can monitor the reaction process of CO2 and water glass in the VRH vacuum working chamber in real time through the 0-100 DEG C temperature transmitter 3-3, the 0-100 Kpa pressure sensor 3-4 and the 0-100 % CO2 gas sensor 3-5.

[0045] In this invention, the MCGS device 2-8 can monitor the CO2 concentration through the flow meter 4-3 and the 1MPa pressure sensor B4-4 to determine whether it needs to be recovered. If it needs to be recovered, it controls the CO2 recovery solenoid valve 4-2 to open; if it does not need to be recovered, it opens the venting solenoid valve 4-1. When the CO2 recovery buffer tank 4-5 is full, it controls the CO2 intake solenoid valve B4-6 to open, so that the recovered CO2 can be reused.

[0046] This invention also provides a CO2 blowing hardening and CO2 recovery process for water glass sand molds, comprising the following steps:

[0047] S1. Put water glass and raw sand into a mixer and mix them thoroughly. After mixing, put the sand into a mold and press it firmly. After processing, a sand mold sample is obtained. Place the sand mold sample and the mold together in the VRH vacuum chamber and place the top cover on the vacuum chamber.

[0048] S2. On the MCGS equipment screen, set the VRH vacuum chamber pressure, CO2 pressure, concentration, temperature, ventilation time, reaction time, and specified recovered CO2 pressure and concentration values, then click Start;

[0049] S3. The vacuum pump first extracts air from the vacuum chamber to reach the set pressure. The CO2 introduced by the CO2 tank and pressure reducing valve group first reduces the pressure of the pressure reducer, then reduces the flow rate of the flow meter, and finally changes the temperature of the heater before being delivered to the VRH vacuum working chamber. After the introduction time is reached, the CO2 vent valve is closed, and the CO2 reacts with the water glass sand mold. After the reaction time is reached, the vacuum pump extracts CO2 from the VRH vacuum working chamber.

[0050] S4. After the reaction, the CO2 will pass through a flow meter and a 1 MPa pressure sensor. If the CO2 concentration reaches the recovery standard, the MCGS equipment will control the CO2 recovery solenoid valve to open, and the CO2 will enter the CO2 recovery buffer tank. If the specified concentration is not reached, the MCGS equipment will control the venting solenoid valve to open, and the CO2 will enter the air. At this time, the manual venting valve can be opened to break the vacuum state. After the pressure in the VRH vacuum working chamber on the MCGS equipment screen returns to 0, open the top cover, take out the mold, and obtain the water glass sand mold.

[0051] In step S1, the modulus of the water glass solution is 2 to 5, the amount of water glass solution added is 2.5 to 5% of the mass of the original sand, and the mixing time of water glass and original sand is 1 to 2 minutes.

[0052] In step S2, the MCGS equipment is set to a vacuum range of -80 to 0 kPa, a ventilation time of 10 s to 2 min, a hardening reaction time of 10 s to 2 min, and a heating temperature of 20 to 80 °C.

[0053] The related embodiments of the application are as follows:

[0054] Embodiment 1

[0055] The embodiment provides a VRH-CO2 method intelligent hardening sodium silicate sand test device, and test operation specifically includes the following steps:

[0056] 1) First, connect the first part of the CO2 gas source with a pressure reducing valve group to the second part through a manual air inlet valve, and set the CO2 entering through an MCGS device, with a CO2 flow rate of 0.66 m3 / h and a ventilation time of 30 s;

[0057] 2) Put sodium silicate and raw sand into a mixer for mixing, with the sodium silicate added in an amount of 2.5%, 3%, 4% and 5% of the mass of the raw sand, and after mixing, the sand is packed into a mold and pressed tightly to obtain a sand mold sample;

[0058] 3) Put in the sample and close the upper cover; vacuumize, and air will be discharged from the one-way valve, the CO2 flow meter, the vacuum pump through the venting electromagnetic valve; after vacuumization, fill in CO2, and the CO2 is filled in through the manual air inlet valve, the CO2 air inlet electromagnetic valve and the one-way valve; after the CO2 is filled in enough, close the CO2 tank, and after a period of time, let the CO2 fully react with the sample; extract the CO2, and the CO2 enters the CO2 recovery tank through the one-way valve, the vacuum pump and the CO2 recovery electromagnetic valve; after the CO2 is extracted, open the venting electromagnetic valve to destroy the vacuum state; open the upper cover, take out the mold, and obtain the sand mold;

[0059] 4) Test the strength of the obtained sample, and the corresponding strength of the 2.5% sodium silicate sand with a peak load of 0.196 kN, 0.143 kN and 0.18 kN is 1 Mpa, 0.73 Mpa and 0.92 Mpa respectively; the corresponding strength of the 3% sodium silicate sand with a peak load of 0.219 kN, 0.119 kN and 0.199 kN is 1.12 Mpa, 0.61 Mpa and 1.01 Mpa respectively; the corresponding strength of the 4% sodium silicate sand with a peak load of 0.278 kN, 0.408 kN and 0.423 kN is 1.42 Mpa, 2.08 Mpa and 2.16 Mpa respectively; and the corresponding strength of the 5% sodium silicate sand with a peak load of 0.414 kN, 0.511 kN and 0.533 kN is 2.11 Mpa, 2.6 Mpa and 2.72 Mpa respectively; it can be known that when the CO2 flow rate is 0.66 m3 / h and the ventilation time is 30 s, the more the sodium silicate added, the greater the strength of the sand mold.

[0060] Embodiment 2

[0061] The embodiment provides a VRH-CO2 method intelligent hardening sodium silicate sand test device, and test operation specifically includes the following steps:

[0062] 1) The second part is connected with the third part through the VRH vacuum chamber, the CO2 gas source of the first part with a pressure reducing valve group is connected with the VRH vacuum chamber and the vacuum pump of the third part through the manual air inlet valve of the second part, and the inlet CO2 is set by the MCGS device, the CO2 flow is set to 0.66m3 / h, and the ventilation time is 40s;

[0063] 2) Put the water glass and the original sand into the mixer for mixing, the water glass is added in an amount of 2.5%, 3%, 4% and 5% of the mass of the original sand, and after mixing, the sand is packed into the mold and pressed tightly to obtain a sand mold sample;

[0064] 3) Put the sample into the mold, close the upper cover, and then vacuumize, during which the air is discharged from the one-way valve, the CO2 flow meter and the vacuum pump through the venting electromagnetic valve; after vacuumizing, CO2 is filled in through the manual air inlet valve, the CO2 inlet electromagnetic valve and the one-way valve; after the CO2 is filled in enough, the CO2 tank is closed, and the reaction process of CO2 and water glass in the vacuum chamber is monitored in real time by the MCGS device through the 0-100℃ temperature transmitter, the 0-100Kpa pressure sensor and the 0-100% CO2 gas sensor, and a period of time is waited for the CO2 to fully react with the sample; CO2 is extracted, and the CO2 is extracted into the CO2 recovery tank through the one-way valve, the vacuum pump and the CO2 recovery electromagnetic valve; after the CO2 is extracted, the manual venting valve is operated to break the vacuum state; open the upper cover, take out the mold, and obtain the sand mold;

[0065] 4) Test the strength of the obtained sample, the peak load of 2.5% water glass sand is 0.119kN, 0.145kN and 0.232kN, and the corresponding strength is 0.61Mpa, 0.74Mpa and 1.18Mpa; the peak load of 3% water glass sand is 0.295kN, 0.266kN and 0.214kN, and the corresponding strength is 1.5Mpa, 1.36Mpa and 1.09Mpa; the peak load of 4% water glass sand is 0.303kN, 0.397kN and 0.266kN, and the corresponding strength is 1.54Mpa, 2.02Mpa and 1.36Mpa, and the peak load of 5% water glass sand is 0.306kN, 0.389kN and 0.308kN, and the corresponding strength is 1.56Mpa, 1.98Mpa and 1.57Mpa; it can be seen that when the CO2 flow is 0.66m3 / h and the ventilation time is 40s, the more the water glass is added, the greater the strength of the sand mold.

[0066] Example 3

[0067] The embodiment provides a VRH-CO2 method intelligent hardening water glass sand test device, and the test operation specifically includes the following steps:

[0068] 1) The fourth part is connected with the second part through the CO2 flow meter, and the second part is connected with the third part through the manual air inlet valve. The recycled CO2 can be introduced into the VRH vacuum chamber of the third part for recycling. The MCGS device is connected with the venting electromagnetic valve, the CO2 recovery electromagnetic valve, the flow meter, the 1Mpa pressure sensor and the CO2 inlet electromagnetic valve signal, and the introduced CO2 is set through the MCGS device. The CO2 flow is set to 0.66m3 / h, and the aeration time is 30s.

[0069] 2) The water glass, raw sand and silica ash are put into the mixer for mixing. The water glass is added in an amount of 3%, 4% and 5% of the mass of the raw sand respectively, and the silica ash is added in an amount of 4g. After mixing, the sand is packed into the mold and pressed tightly to obtain a sand mold sample.

[0070] 3) The sample is put in and the upper cover is closed. Vacuum is drawn, and air is discharged through the one-way valve, the CO2 flow meter, the vacuum pump and the venting electromagnetic valve. After vacuum is reached, CO2 is filled in through the manual air inlet valve, the CO2 inlet electromagnetic valve and the one-way valve. After sufficient CO2 is filled in, the CO2 filling tank is closed, and a period of time is waited for the CO2 to fully react with the sample. The CO2 concentration is monitored by the MCGS device through the flow meter and the 1Mpa pressure sensor, and the CO2 recovery electromagnetic valve is controlled to be opened for CO2 recovery. CO2 is drawn in through the one-way valve, the vacuum pump and the CO2 recovery electromagnetic valve into the CO2 recovery tank. When the CO2 recovery buffer tank is full, the CO2 inlet electromagnetic valve is controlled to be opened, so that the recovered CO2 can be reused. When the CO2 extraction is completed, the venting electromagnetic valve is opened to destroy the vacuum state. The upper cover is opened, the mold is taken out, and the sand mold is obtained.

[0071] 4) The strength of the obtained sample is tested. The peak load of the 3% water glass sand is 0.39kN, 0.327kN and 0.362kN, and the corresponding strength is 1.99Mpa, 1.67Mpa and 1.84Mpa. The peak load of the 4% water glass sand is 0.574kN, 0.494kN and 0.542kN, and the corresponding strength is 2.92Mpa, 2.52Mpa and 2.76Mpa. The peak load of the 5% water glass sand is 0.74kN, 0.67kN and 0.69kN, and the corresponding strength is 3.77Mpa, 3.41Mpa and 3.52Mpa. It can be seen that when the CO2 flow is 0.66m3 / h, the aeration time is 30s, and the silica ash addition amount is 4g, the more the water glass addition amount, the greater the strength of the sand mold.

[0072] Example 4

[0073] The present embodiment provides a VRH-CO2 method intelligent hardening water glass sand test device. The test operation specifically includes the following steps:

[0074] 1) The first part of the pressure reducer can be used to preliminarily reduce the pressure of CO2 in the CO2 gas source, and the second part is the control part, which sequentially connects the manual air inlet valve, the pressure reducer, the 1Mpa pressure sensor, the throttle valve, the CO2 inlet electromagnetic valve, the CO2 flowmeter and the gas heater, so that the pressure reducer, the CO2 inlet electromagnetic valve, the CO2 flowmeter and the gas heater are connected with the MCGS signal, and the MCGS device is used to set the CO2 flow to 0.66m3 / h and the ventilation time to 40s;

[0075] 2) The water glass, the raw sand and the silica fume are mixed in the blender, the water glass is added in an amount of 3%, 4% and 5% of the mass of the raw sand respectively, and the silica fume is added in an amount of 4g, then the sand is packed into the mold after mixing, and the sand mold sample is obtained;

[0076] 3) After the sample is placed, the upper cover is closed, the vacuum is extracted, the air is discharged from the one-way valve, the CO2 flowmeter, the vacuum pump through the vent electromagnetic valve, the CO2 is filled after the vacuum is reached, the CO2 is filled through the manual air inlet valve, the CO2 inlet electromagnetic valve and the one-way valve, the CO2 tank is closed after the CO2 is filled enough, and the CO2 and the sample are fully reacted after a period of time; the CO2 is extracted, the CO2 is extracted through the one-way valve, the vacuum pump and the CO2 recovery electromagnetic valve, and the CO2 is recovered into the CO2 recovery tank; when the CO2 is extracted, the vent electromagnetic valve or the manual vent valve is opened to destroy the vacuum state; the upper cover is opened, the mold is taken out, and the sand mold is obtained.

[0077] 4) The strength of the obtained sample is tested, the corresponding strength of the 3% water glass sand with the peak load of 0.46kN, 0.47kN and 0.472kN is 2.34Mpa, 2.39Mpa and 2.40Mpa, the corresponding strength of the 4% water glass sand with the peak load of 0.646kN, 0.794kN and 0.705kN is 3.29Mpa, 4.05Mpa and 3.59Mpa, and the corresponding strength of the 5% water glass sand with the peak load of 0.533kN, 0.521kN and 0.719kN is 2.72Mpa, 2.65Mpa and 3.66Mpa, it can be seen that when the CO2 flow is 0.66m3 / h, the ventilation time is 40s, and the silica fume addition amount is 4g, the strength of the sand mold with the water glass addition amount of 4% is the largest.

[0078] Example 5

[0079] The embodiment provides a VRH-CO2 method intelligent hardening water glass sand test device, and the test operation specifically includes the following steps:

[0080] 1) The third part of the VRH vacuum chamber, pressure reducer, manual vent valve, vent solenoid valve and vacuum pump are connected in sequence; 0-100% CO2 gas sensor is installed on the outer barrel wall of the VRH vacuum chamber, 0-100℃ temperature transmitter and 0-100Kpa pressure sensor are installed on the upper cover, and the upper cover is placed above the vacuum chamber to observe the instrument data at any time; MCGS device is connected with 0-100℃ temperature transmitter, 0-100Kpa pressure sensor and 0-100% CO2 gas sensor signal, and the inlet CO2 is set through MCGS device, and the CO2 flow is set to 0.56m3 / h, 0.66m3 / h, 0.76m3 / h, 0.86m3 / h and 0.96m3 / h respectively, and the ventilation time is 40s;

[0081] 2) Put water glass, raw sand and silica ash into the mixer and mix, the amount of water glass added is 4% of the mass of raw sand, and the amount of silica ash added is 4g, after mixing, the sand is packed into the mold and pressed tightly to obtain a sand mold sample;

[0082] 3) After the sample is put in, close the upper cover; vacuumize, air will be discharged from the one-way valve, CO2 flow meter, vacuum pump through the vent solenoid valve; after reaching vacuum, fill in CO2, CO2 is filled in through the manual air inlet valve, CO2 air inlet solenoid valve and one-way valve; after the amount of CO2 is filled enough, close the CO2 tank, wait for a period of time to let CO2 fully react with the sample; extract CO2, CO2 enters the CO2 recovery tank through the one-way valve, vacuum pump and CO2 recovery solenoid valve; after CO2 is extracted, operate the manual vent valve to break the vacuum state; remove the upper cover, take out the mold, and get the sand mold.

[0083] 4) The strength of the obtained sample is tested, the peak load of the sand mold is 0.892 kN, 1.179 kN, and 0.82 kN, and the corresponding strength is 4.55 Mpa, 6 Mpa, and 4.18 Mpa when the CO2 flow rate is 0.56 m3 / h, the peak load of the sand mold is 0.983 kN, 0.805 kN, and 0.765 kN when the CO2 flow rate is 0.66 m3 / h, the peak load of the sand mold is 0.67 kN, 0.663 kN, and 0.652 kN when the CO2 flow rate is 0.76 m3 / h, the peak load of the sand mold is 0.472 kN, 0.651 kN, and 0.626 kN when the CO2 flow rate is 0.86 m3 / h, and the peak load of the sand mold is 0.415 kN, 0.561 kN, and 0.55 kN when the CO2 flow rate is 0.96 m3 / h, the corresponding strength is 2.4 Mpa, 3.32 Mpa, and 3.19 Mpa, respectively. It can be seen that when the CO2 ventilation time is 40 s, the silica fume addition amount is 4 g, and the water glass addition amount is 4%, the sand mold strength is the largest when the CO2 flow rate is 0.56 m3 / h and 0.66 m3 / h.

[0084] Example 6

[0085] The present embodiment provides a VRH-CO2 method intelligent hardening water glass sand test device, and the test operation specifically includes the following steps:

[0086] 1) The CO2 recovery solenoid valve, flow meter, 1Mpa pressure sensor, CO2 recovery buffer tank and CO2 inlet solenoid valve of the fourth part are sequentially connected, the venting solenoid valve is installed above the CO2 recovery solenoid valve, the MCGS device is connected with the CO2 recovery solenoid valve, flow meter, 1Mpa pressure sensor and CO2 inlet solenoid valve, and the MCGS device is used to set the CO2 flow rate, which is set to 0.56 m3 / h, 0.66 m3 / h, 0.76 m3 / h, 0.86 m3 / h and 0.96 m3 / h, and the ventilation time is 40 s;

[0087] 2) The water glass, raw sand and bentonite are put into the mixer and mixed, the water glass addition amount is 4% of the mass of the raw sand, the bentonite addition amount is 4 g, the sand is packed into the mold after mixing, and the sand mold sample is obtained;

[0088] 3) Put the sample, close the upper cover; vacuumize, the air will be discharged from the one-way valve, CO2 flow meter, vacuum pump through the venting electromagnetic valve; after reaching the vacuum, fill in CO2, CO2 is filled in through the manual air inlet valve, CO2 air inlet electromagnetic valve, one-way valve; after the CO2 amount is filled enough, close the CO2 gas tank, wait for a period of time to let the CO2 fully react with the sample; extract CO2, CO2 enters the CO2 recovery tank through the one-way valve, vacuum pump, CO2 recovery electromagnetic valve; when the CO2 is extracted, open the venting electromagnetic valve or operate the manual venting valve to break the vacuum state; open the upper cover, take out the mold, and get the sand mold;

[0089] 4) Test the strength of the obtained sample, when the CO2 flow is 0.56 m3 / h, the peak load of the sand mold is 0.504 kN, 0.36 kN, and 0.248 kN, and the corresponding strength is 2.57 Mpa, 1.83 Mpa, and 1.26 Mpa; when the CO2 flow is 0.66 m3 / h, the peak load of the sand mold is 0.267 kN, 0.53 kN, and 0.408 kN, and the corresponding strength is 1.36 Mpa, 2.7 Mpa, and 2.08 Mpa; when the CO2 flow is 0.76 m3 / h, the peak load of the sand mold is 0.223 kN, 0.193 kN, and 0.38 kN, and the corresponding strength is 1.14 Mpa, 0.98 Mpa, and 1.94 Mpa; when the CO2 flow is 0.86 m3 / h, the peak load of the sand mold is 0.178 kN, 0.213 kN, and 0.2 kN, and the corresponding strength is 0.91 Mpa, 1.09 Mpa, and 1.02 Mpa; when the CO2 flow is 0.96 m3 / h, the peak load of the sand mold is 0.259 kN, 0.227 kN, and 0.168 kN, and the corresponding strength is 1.32 Mpa, 1.16 Mpa, and 0.86 Mpa; it can be seen that when the CO2 ventilation time is 40 s, the bentonite addition amount is 4 g, and the water glass addition amount is 4%, the strength of the sand mold with the CO2 flow of 0.66 m3 / h is the largest, the strength of the sand mold with the CO2 flow of 0.56 m3 / h is the second, but the difference between the two is not large.

[0090] The preferred embodiments disclosed above are only used to help explain the present application. The preferred embodiments do not describe all the details and do not limit the present application to the specific embodiments. Obviously, many modifications and changes can be made according to the content of the present application. The present application is selected and described in detail to better explain the principles and practical applications of the present application, so that those skilled in the art can well understand and utilize the present application. The present application is limited by the claims and their entire scope and equivalents.

Claims

1. A VRH-CO2 method intelligent hardening water glass sand testing device, characterized in that, include: The first part includes a CO2 gas source (1-1) and a first pressure reducer (1-2), which can perform preliminary pressure reduction on the CO2 in the CO2 gas source (1-1); The second part includes a manual intake valve (2-1), a second pressure regulator (2-2), a 1MPa pressure sensor A (2-3), a throttle valve (2-4), a CO2 intake solenoid valve A (2-5), a CO2 flow meter (2-6), a gas heater (2-7), and an MCGS device (2-8). The manual intake valve (2-1), the second pressure regulator (2-2), the 1MPa pressure sensor A (2-3), the throttle valve (2-4), the CO2 intake solenoid valve A (2-5), the CO2 flow meter (2-6), and the gas heater (2-7) are connected in sequence. The second pressure regulator (2-2), the CO2 intake solenoid valve A (2-5), the CO2 flow meter (2-6), and the gas heater (2-7) are respectively connected to the MCGS device (2-8) for signal transmission. The third part includes a VRH vacuum chamber (3-1), a top cover (3-2), a 0-100℃ temperature transmitter (3-3), a 0-100Kpa pressure sensor (3-4), a 0-100%CO2 gas sensor (3-5), a third pressure reducer (3-6), a manual vent valve (3-7), a vent solenoid valve (3-8), and a vacuum pump (3-9). The VRH vacuum chamber (3-1), the third pressure reducer (3-6), the manual vent valve (3-7), the vent solenoid valve (3-8), and the vacuum pump (3-9) are connected in sequence. The 0-100%CO2 gas sensor (3-5) is installed on the outer wall of the VRH vacuum chamber (3-1), and the 0-100℃ temperature transmitter (3-3) and the 0-100Kpa pressure sensor (3-4) are installed on the top cover (3-2). The instrument data can be observed at any time during the experiment. The fourth part includes an venting solenoid valve (4-1), a CO2 recovery solenoid valve (4-2), a flow meter (4-3), a 1 MPa pressure sensor B (4-4), a CO2 recovery buffer tank (4-5), and a CO2 inlet solenoid valve B (4-6). The venting solenoid valve (4-1) is installed above the CO2 recovery solenoid valve (4-2). The CO2 recovery solenoid valve (4-2), the flow meter (4-3), the 1 MPa pressure sensor B (4-4), the CO2 recovery buffer tank (4-5), and the CO2 inlet solenoid valve B (4-6) are connected in sequence. The first pressure reducer (1-2) of the first part is connected to the manual air inlet valve (2-1) of the second part; the manual air inlet valve (2-1) of the second part is connected to the VRH vacuum chamber (3-1) of the third part. During the experiment, the recovered CO2 can be introduced into the VRH vacuum chamber (3-1) of the third part for recycling and reuse; the vacuum pump (3-9) of the third part is connected to the CO2 recovery solenoid valve (4-2) of the fourth part; the CO2 inlet solenoid valve B (4-6) of the fourth part is connected to the CO2 flow meter (2-6) of the second part. The MCGS device (2-8) can monitor the CO2 concentration through a flow meter (4-3) and a 1MPa pressure sensor B (4-4) to determine whether it needs to be recovered. If it needs to be recovered, it controls the CO2 recovery solenoid valve (4-2) to open; if it does not need to be recovered, it opens the venting solenoid valve (4-1). When the CO2 recovery buffer tank (4-5) is full, it controls the CO2 intake solenoid valve B (4-6) to open, so that the recovered CO2 can be reused.

2. The VRH-CO2 method intelligent hardening water glass sand testing device according to claim 1, characterized in that, The MCGS equipment (2-8) is connected to the signals of the 0-100℃ temperature transmitter (3-3), the 0-100Kpa pressure sensor (3-4), and the 0-100%CO2 gas sensor (3-5), respectively.

3. The VRH-CO2 method intelligent hardening water glass sand testing device according to claim 1, characterized in that, The top cover (3-2) is placed above the VRH vacuum chamber (3-1) during the experiment. After the experiment, the sand mold is removed by taking off the top cover (3-2).

4. The VRH-CO2 method intelligent hardening water glass sand testing device according to claim 1, characterized in that, The MCGS device (2-8) is connected to the CO2 recovery solenoid valve (4-2), the flow meter (4-3), the 1MPa pressure sensor B (4-4), and the CO2 intake solenoid valve B (4-6) respectively.

5. The VRH-CO2 method intelligent hardening water glass sand testing device according to claim 1, characterized in that, The MCGS device (2-8) can set the incoming CO2 through the second pressure reducer (2-2), 1Mpa pressure sensor A (2-3), and CO2 flow meter (2-6).

6. The VRH-CO2 method intelligent hardening water glass sand testing device according to claim 1, characterized in that, The MCGS equipment (2-8) can monitor the reaction process of CO2 and water glass in the VRH vacuum chamber in real time through a 0-100℃ temperature transmitter (3-3), a 0-100Kpa pressure sensor (3-4), and a 0-100%CO2 gas sensor (3-5).

7. A CO2 blowing hardening and CO2 recovery process for water glass sand, implemented based on the VRH-CO2 method intelligent hardening water glass sand test device according to any one of claims 1-6, characterized in that, Includes the following steps: S1. Put water glass and raw sand into a mixer and mix them thoroughly. After mixing, put the sand into a mold and press it firmly. After processing, a sand mold sample is obtained. Place the sand mold sample and the mold together in the VRH vacuum chamber and place the top cover on the vacuum chamber. S2. On the MCGS equipment screen, set the VRH vacuum chamber pressure, CO2 pressure, concentration, temperature, ventilation time, reaction time, and specified recovered CO2 pressure and concentration values, then click Start; S3. The vacuum pump first extracts air from the vacuum chamber to reach the set pressure. The CO2 introduced by the CO2 tank and pressure reducing valve group first reduces the pressure of the pressure reducer, then reduces the flow rate of the flow meter, and finally changes the temperature of the heater before being delivered to the VRH vacuum working chamber. After the introduction time is reached, the CO2 vent valve is closed, and the CO2 reacts with the water glass sand mold. After the reaction time is reached, the vacuum pump extracts CO2 from the VRH vacuum working chamber. S4. After the reaction, the CO2 will pass through a flow meter and a 1 MPa pressure sensor. If the CO2 concentration reaches the recovery standard, the MCGS equipment will control the CO2 recovery solenoid valve to open, and the CO2 will enter the CO2 recovery buffer tank. If the specified concentration is not reached, the MCGS equipment will control the venting solenoid valve to open, and the CO2 will enter the air. At this time, the manual venting valve can be opened to break the vacuum state. After the pressure in the VRH vacuum working chamber on the MCGS equipment screen returns to 0, open the top cover, take out the mold, and obtain the water glass sand mold.

8. The CO2 blowing hardening and CO2 recovery process for water glass sand molds according to claim 7, characterized in that, In step S1, the modulus of the water glass solution is 2 to 5, the amount of water glass solution added is 2.5 to 5% of the mass of the original sand, and the mixing time of water glass and original sand is 1 to 2 minutes. In step S2, the MCGS equipment is set to a vacuum range of -80 to 0 kPa, a ventilation time of 10 s to 2 min, a hardening reaction time of 10 s to 2 min, and a heating temperature of 20 to 80 °C.

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