CN102087259B - Foam performance testing method and testing device - Google Patents

Abstract

The invention relates to a foam performance testing method, which comprises a foam resistance testing method and a defoaming performance testing method, wherein the two testing methods comprise the following steps: firstly, 800ml to 1200ml of liquid to be detected is added in advance into a transparent test tube with the inner diameter of 20mm to 100mm and the volume of 2200ml to 3500 ml; injecting the liquid to be detected vertically and downwards at the position which is 30-80 cm away from the liquid level in the step I at the flow rate of 2-12L/min to generate foam, and simultaneously, allowing the liquid to be detected to flow out from the bottom of the test tube at the same speed; then, the amount and time of the generated foam, and the subsequent foam elimination time are used as corresponding parameters. Also relates to a foam performance testing device. The invention can avoid many errors caused by manual operation; the method is not only suitable for evaluating the defoaming effect of the defoaming agent for the processing liquid at various temperatures, but also can be used for evaluating the anti-foaming effect of various systems without adding the defoaming agent and the defoaming performance of other water-based products (cleaning agents and the like).

Description

Foam performance test method and test device

technical field

The invention relates to the technical field of foam testing, in particular to a foam performance testing method and a corresponding testing device.

Background technique

Foam and foam are common phenomena in people's daily life and chemical production, but few people know about foam and foam, and a mature, complete and unified theoretical system of foam has not yet been formed. In the industry, people pay more and more attention to how to better utilize and eliminate foam, which is particularly urgent in the metalworking fluid industry, especially in water-based metalworking fluids, because the existence of foam can affect the cooling, rust prevention, lubrication, etc. of the working fluid. The performance will cause damage, and it will also bring pressure to the machine tool environment, such as machine tool blockage, foam overflow tank, etc., in addition, it will also cause ineffective loss of defoamers and cutting fluids. Therefore, foam performance is an important monitoring indicator for metalworking fluids, and the foaming effect of metalworking fluids must be strictly controlled.

The foam control of water-based processing fluid is reflected in two aspects: one is defoaming, which is to eliminate the foam that has been generated; the other is anti-foam or anti-foam, that is, to prevent or suppress the generation of bubbles during the use of the processing fluid. For the metalworking fluid industry, these two aspects are very important, they are two important aspects for evaluating the foam effect, and they are also important indicators for defoamer screening. At present, the evaluation method for the foam effect of water-based metalworking fluid is relatively simple. For example, the national standard test method GB/T6144-85, one of the manual power methods, is also known as the foam elimination method, that is, after the water-based processing fluid is diluted with 5%, it is placed in a measuring cylinder and shaken violently to generate a large amount of foam, and then The defoaming performance is determined by the time required for the foam volume to decrease to a certain amount. The shorter the required time, the stronger the defoaming performance; or the defoaming performance is determined by the foam volume after a certain period of time. The smaller the foam volume, the better The stronger the defoaming ability. However, this method has the following disadvantages: (1) Due to the deviation of human operation, it will inevitably introduce systematic errors; (2) This test method has the disadvantage of poor repeatability; (3) It cannot simulate the actual operation of the factory. Dynamic process; (4) can only display the foam data of the final state, but cannot display the dynamic data of the foam; (5) cannot reflect the relationship between defoaming performance and temperature; (6) cannot test the anti-foaming effect; (7) measure The standard is single, and the corresponding standard cannot be effectively determined according to different working conditions; (8) The accuracy is poor, and effective comparison tests cannot be carried out for several processing fluids with similar foam effects. It is precisely because this method is not easy to standardize and unify the operation, and it is very easy to introduce errors, resulting in large errors in the measurement results. Therefore, this method can no longer meet the needs of the current development of metalworking fluids.

Contents of the invention

The present invention aims at the deficiencies of the above-mentioned prior art, and provides a foam performance test method, which includes an anti-foam performance test method and a defoamer performance test method, which can accurately measure the foam effect under dynamic conditions and has good repeatability.

In order to solve the above-mentioned technical problems, the present invention adopts the following technical solutions: a method for testing anti-foam performance, comprising the following steps:

①. In a transparent test tube with an inner diameter of 20mm~100mm and a volume of 2200ml~3500ml, add 800ml~1200ml of the solution to be tested in advance;

②. At a height of 30cm to 80cm from the liquid level in step ①, inject the liquid to be tested vertically downward at a flow rate of 2L/min to 12L/min to generate foam, and at the same time, the liquid to be tested flows out from the bottom of the test tube at the same speed;

When 1000ml of foam is produced, record the elapsed time; or

When the elapsed time is 150min and the amount of foam generated is less than 1000ml, record the amount of foam generated and the elapsed time.

Preferably, the time taken for every 100ml of foam generated is recorded.

Preferably, the position for injecting the liquid to be tested in step ② is at the center of the liquid surface.

A kind of defoaming performance testing method, comprises the following steps:

(1) Add 800ml to 1200ml of the solution to be tested in advance into a transparent straight tube with an inner diameter of 20mm to 100mm and a volume of 2200ml to 3500ml;

(2) At a height of 30cm to 80cm from the liquid level in step (1), inject the liquid to be tested vertically downward at a flow rate of 2L/min to 12L/min to generate foam, and at the same time, the liquid to be tested is poured from the bottom of the test tube by the same pressure. speed out;

(3), the process of step (2) is maintained for 80 minutes to 100 minutes, and at the same time stop injecting the test solution into the test tube and flowing out the test solution from the test tube;

When the foam disappears to a volume of 40ml, record the time elapsed; or

When the foam volume is less than 40ml, record the elapsed time until the foam volume disappears to 0ml.

Preferably, the position where the liquid to be tested is injected in step (2) is at the center of the liquid level.

Preferably, record the time it takes for every 100ml of foam to disappear.

Compared with the prior art, the present invention vertically drops the liquid to be tested from a certain height at a certain flow rate to the liquid surface of the same solution pre-loaded in the transparent straight tube, and at the same time the solution below flows out from the bottom at the same speed, during which process Foam: The anti-foaming effect is determined according to the volume of foam produced (the total volume of foam and liquid in the transparent straight tube minus the volume of the pre-filled solution) and the experimental time. The longer the time and the smaller the foam volume, it indicates the anti-foaming property the better.

Also, the liquid to be tested is circulated in the transparent straight tube, so that the liquid to be tested falls vertically from a certain height to the surface of the same solution at a certain flow rate, and after a certain period of circulation, the pump is stopped to test the defoaming. The time to determine its defoaming effect, the shorter the time, the better the defoaming effect.

When the flow rate of the liquid to be tested is fixed and the same instrument is used, the foam volume and foaming time can be used as the measure of the anti-foaming effect; because the foam volume and the foaming time are at a certain liquid flow rate and a certain position difference, the foam generation and The result of destroying the joint effect, so this amount includes two properties of foaming and defoaming (that is, anti-foaming performance); and at a certain temperature, flow rate and potential difference, the defoaming time after the test liquid circulates for a certain amount of time Reflects the defoaming properties.

The present invention fully considers the causes of foam generation in the water-based processing fluid, the influence of various factors such as liquid flow rate, injection pressure and temperature, simulates the working mode of the dynamic cycle of the actual working condition, and expresses the test results by measuring the foaming time and volume. The longer the time and the smaller the foam volume, the better the antifoaming effect; in the same defoaming test, the shorter the defoaming time, the better the defoaming effect.

The invention is easy to operate and use, and can avoid many errors caused by manual operation; it can set corresponding test standards and quantify test results according to actual processing conditions; it is not only suitable for defoaming of defoamers for processing fluids at various temperatures Effect evaluation, and can be used to evaluate the anti-foaming effect of various systems without adding defoamers; simulate the actual working conditions of the circulating flow in the factory, so as to have a feasible guiding role in the application of processing fluids in actual working conditions. In short, this method can be used to eliminate after-sales service factors caused by foam generation, improve product reliability and brand image, and then improve customer satisfaction; at the same time, it can also be used for the establishment of foam performance testing standards in the domestic water-based processing fluid industry It provides a feasible direction and can also be extended to evaluate the foam performance of water-based products in other industries.

The present invention also provides a test device for measuring foam properties, the device comprises a pump, a valve and a vertically arranged transparent straight pipe connected in sequence by a circulation pipeline, the transparent straight pipe has an inner diameter of 20 mm to 100 mm and a volume of 2200ml～3500ml, and add 800ml～1200ml of the liquid to be tested in advance; the height of the pipeline outlet connected to the upper end of the transparent straight tube from the liquid level in the transparent straight tube is 30cm～80cm; the flow rate of the liquid to be tested in the valve control pipeline is 2L/ min～12L/min.

Preferably, the pipe outlet connected to the upper end of the transparent straight pipe is located directly above the center of the liquid surface in the transparent straight pipe.

Preferably, the device further includes a constant temperature water bath device, the transparent straight pipe is provided with a jacket, and the constant temperature water bath device communicates with the jacket.

Preferably, the device further includes a flow meter, and the flow meter is arranged in the pipeline between the valve and the transparent straight pipe.

The test device of the present invention has the following beneficial effects: reasonable structure, convenient operation, use and maintenance, low operating cost, etc., can avoid many errors caused by manual operation, good test repeatability, test records can obtain foam certain dynamic data; and considering the influence of various factors such as flow velocity, injection pressure and temperature in actual working conditions, the actual working conditions of dynamic cycle are simulated, and the performance of water-based processing fluids under different temperature and flow velocities can be objectively evaluated. The dynamic defoaming effect plays a certain guiding role in the actual working conditions; in a word, the invention is suitable for the evaluation of the foam effect of water-based processing fluids at various temperatures, and has practical significance for the actual application of processing fluids and the improvement of processing fluid products , the method has a good promotion prospect in the water-based metalworking fluid industry.

Description of drawings

FIG. 1 is a schematic structural view of the foam effect dynamic cycle test device of the present invention.

Fig. 2 is the anti-foam curve figure of different defoamer additions;

Fig. 3 is the anti-foaming curve that different ionic water hardness new methods measure;

Fig. 4 is the defoaming curve measured by the new method of different ionic water hardness.

Detailed ways

The present invention will be described in detail below in conjunction with specific embodiments and drawings. The description in this part is only exemplary and explanatory, and should not have any limiting effect on the protection scope of the present invention.

The foam effect dynamic circulation testing device as shown in Figure 1, it is made of constant temperature jacket (organic) glass tube 1, circulation booster pump 2, throttle valve 3, super constant temperature water bath 4, stainless steel rotameter 5 and appropriate amount Silicon tube composition.

的L型导管，其外管上有刻度。若要控制温度时，从恒温夹套(有机)玻璃管1下方的进水口进水，上方的出水口出水，形成水浴循环，达到保温效果。通过启动循环增压泵2及根据不锈钢转子流量计5来调整节流阀3，从而使得待测液以一定流速循环流动，以模拟加工液的实际工作状态。Thermostatic jacketed (organic) glass tube 1 has an inner diameter of 20mm to 100mm, a volume of 2200ml to 3500ml, and an outer diameter of 30mm to 110mm.

The L-shaped catheter has a scale on its outer tube. When the temperature is to be controlled, water is taken in from the water inlet below the thermostatic jacket (organic) glass tube 1, and water is discharged from the water outlet above to form a water bath cycle to achieve the heat preservation effect. By starting the circulation booster pump 2 and adjusting the throttle valve 3 according to the stainless steel rotameter 5, the fluid to be tested circulates at a certain flow rate to simulate the actual working state of the machining fluid.

The working process of adopting above-mentioned testing device to measure the performance parameter of foam is as follows:

1) Prepare at least 1500ml of the test solution as the test object.

2) First assemble the device as shown in Figure 1 and check for leaks; then use 1500ml of deionized water to circulate and clean the device for 3 to 5 times each time; after cleaning, rinse the device with 300ml of the liquid to be tested for 3 to 5 minutes; Inject the liquid to be tested to the scale of 800ml ~ 1200ml, and at the same time adjust the nozzle to be in the center and vertical to the liquid surface and the height from the liquid surface is 30cm ~ 80cm;

3) Turn on the super constant temperature water bath 4 to rise to a suitable temperature, and start the electric pump to form a water bath cycle, so that the temperature in the constant temperature jacket (organic) glass tube 1 rises to the specified temperature (if the temperature requirements are not strict, then step can be ignored).

4) Start the circulating booster pump and adjust to a specific flow rate (generally 2-12L/min).

5) If the anti-foaming property is measured, start the pump when there is no foam on the liquid surface and press the stopwatch to conduct the experiment; record the time every time 100ml of foam is generated (foam volume = total liquid volume - volume of pre-filled liquid to be tested) until the foam When the volume is 1000ml, record the total time at this moment (T ₁ /s) and record the foam volume as 1000ml, or when the total time is 150min, record the foam volume (V/ml) and time (T ₂ = 150min) as the evaluation index of anti-foaming property (that is, the comprehensive performance of foam generation and destruction) (the longer the time and the smaller the foam volume, the better the anti-foaming property); stop the circulating pump immediately at this moment, and restart the foaming with a stopwatch at the same time Start to record the time, and record the time every time 100ml of foam is eliminated, until the foam is 40ml, record the total time (T ₃ /s) at this time as the evaluation index of the defoaming performance of the system under this condition.

6) If you want to evaluate the defoaming performance, start the pump when the liquid surface is free of foam and press the stopwatch to conduct the experiment. First, after the cycle time of the test object is 80min to 100min (generally 90min), immediately stop the circulating pump and return the stopwatch to Zero, and restart the stopwatch immediately, record the time every time 100ml of foam is eliminated, until the foam is 40ml, record the total time (T ₄ /s) at this time as the evaluation index of defoaming (the shorter the time, the The better its defoaming performance).

7) In the test, the arithmetic mean of three parallel tests is generally taken as the analysis result.

8) Immediately after the test is completed, the liquid to be tested is discharged, and at the same time, the device is circularly cleaned with 1500ml of deionized water for 3 to 5 times each time, for the next test.

Comparative experiment example

1. The same emulsification system with different defoamer additions

In the same emulsified system, the same defoamer (siloxane type) was added, but the addition amount was different, and the defoaming property was tested by the hand-operated dynamic method and the method of the present invention mentioned above.

1.1. The defoaming property was tested by the manual dynamic method, and the results are shown in Table 1 below.

Table 1 The results of the manual dynamic method test of the defoaming properties (5%) of different additions of defoamers

It can be seen from the results in Table 1 that when the amount of the additive exceeds 0.3%, the error of testing its defoaming property by this method is relatively large, and the degree of defoaming cannot be well distinguished.

1.2, adopt the above-mentioned method of the present invention to test its anti-foaming property (being anti-foaming property), test result is shown in Table 2 and Fig. 2.

The antifoaming test result of new method when table 2 defoamer addition is different

Draw the measured data in the table into a curve, as shown in Figure 2.

As can be seen from Table 2 and Figure 2 above, the more the defoamer is added, the better the apparent anti-foaming property of the system (that is, its anti-foaming property is also better), and it is also used in metal processing. more favorable. Since their foaming systems are the same, that is to say, their anti-foaming (anti-foaming) essence should be the same, and the difference in apparent anti-foaming properties is caused by the difference in defoaming effect, that is, the measurement The result also reflects its defoaming effect indirectly in essence.

The above measurement results show that: when a small amount of defoamer is added to the defoaming system, the more the defoamer is added, the better the apparent antifoaming property is, that is, the better the defoaming effect is reflected from the side . In addition, it can be seen from Figure 1 that when the amount of foam is less, it takes more time to generate the same unit amount of foam, that is, the better the foam resistance (essentially, the better the defoaming effect); There are three reasons for this phenomenon: First, because the defoamer is dispersed in the system, it is in a metastable state in the system, and the increase in the amount of foam will have a greater impact on the metastable state, and it will also It affects the defoaming effect; the second is that the distribution of the silicon-containing defoamer in the foam decreases with the increase of the foam thickness, so the defoaming effect will also decrease; the third is that as the amount of foam increases, The content of gas in the system will also increase accordingly, which will also cause a rapid decline in the anti-foaming performance of the system.

Within a certain range, although the defoaming effect increases rapidly with the increase in the amount of defoamer added, it is necessary to consider the stability of the defoamer in the system and the factors of defoaming persistence to choose a reasonable amount. .

2. Influence of the hardness of dilution water on the effect of foam suppression and defoaming

For water-based metalworking fluids, generally, the higher the hardness of the water used for diluting, the more favorable the anti-foaming and defoaming effect of the cutting fluid during work. In order to verify this conclusion, by artificially adding 0.4% (mass fraction) CaCl ₂ or 1.0% (mass fraction) MgSO ₄ .10H ₂ O in a system X to simulate the antifoaming effect of different ions on the system under almost the same water hardness The effect of defoaming. Tested by hand power method and the new test method in this paper.

2.1. The test results of the hand-cranking dynamic method are shown in Table 3.

Table 3 The test results of the manual dynamic method on the influence of different ionized water hardness on the defoaming effect

system x X+0.4% _CaCl2 X+1.0%MgSO ₄ .10H ₂ O Complete defoaming time (s) twenty two 11 15

2.2, adopt the method of the present invention to test its anti-foaming property and the defoaming property in the same cycle time (both 9000s), the anti-foaming property test result is shown in Table 4 and Fig. 3, and the defoaming property test result is shown in Table 5 and Fig. 4 Show.

Table 4 Anti-foaming test results of different ion water hardness new methods

Plot the data in Table 4 into a curve, as shown in Figure 3.

Table 5 The defoaming test results of the new method with different ionized water hardness after the cycle for the same time (9000s)

Plot the data in Table 5 into a curve, as shown in Figure 4.

It can be seen from Table 5 and Figure 4 that the addition of compounds containing magnesium ions and calcium ions is equivalent to diluting with hard water with a certain hardness value during work, which is beneficial to the anti-foaming and defoaming of the working fluid; This is because the addition of electrolytes makes the electric repulsion weaken the stability of the foam, which is not conducive to the formation of foams. At the same time, the addition of electrolytes can weaken the repulsion of the electric double layer, which is conducive to the agglomeration of small bubbles into large bubbles. To achieve the purpose of accelerating defoaming; the above experimental measurement results also confirmed this conclusion. At the same time, it can also be seen from the above results that although the hardness of dilution water simulated by adding 0.4% CaCl ₂ and 1.0% MgSO ₄ .10H ₂ O is basically the same, the anti-foaming and defoaming effects of adding 0.4% CaCl ₂ are obviously better 1.0% MgSO ₄ .10H ₂ O, therefore, only from the point of view of anti-foaming and defoaming, it is a better choice to add 0.4% CaCl ₂ , but we also need to consider the addition of electrolytes (that is, similar to water water hardness) on the rust resistance of the working fluid and the corrosion resistance of some metals (such as the addition of 0.4% CaCl ₂ to the corrosion resistance of aluminum is far worse than the addition of 1.0% MgSO ₄ .10H ₂ O), only Taking into account the consideration of various performances of the working fluid and the requirements of the customer's actual process, we can determine a better addition scheme.

Through the analysis of the principles, experimental procedures and experimental cases of the above two methods, it can be seen that the new method of anti-foaming and defoaming test (ie dynamic anti-foaming and defoaming test method) has the following advantages:

(1) As can be seen from the device diagram of the present invention and the experimental procedure, this new test method is relative to the national standard method, and its screen removes the unavoidable human factor deviation;

(2) because the inventive method does not introduce uncontrollable man-made deviation factor, therefore can reduce error by taking average value through repeated experiments;

(3) the test process of the test method of the present invention has simulated the actual working conditions of circulating flow in the factory, thereby its result has instructive effect to actual working conditions;

(4) data is recorded once per 100ml of foam volume in the method test process of the present invention, and this has also just obtained the dynamic data of foam in a period of time to a certain extent, thereby can obtain more vivid concrete foam formation situation therefrom;

(5) As long as a constant temperature component (such as an appropriate container placed in a super constant temperature water bath, etc.) is added to the device, constant temperature or high and low temperature test experiments can be carried out;

(6) The testing method of the present invention can set the threshold value (i.e. the qualified standard value) of the quantitative index according to different processing conditions, different equipment requirements, etc., that is, the qualified standard depends on the actual working conditions, and this mode is more In line with the actual use of cutting fluid;

(7) the record of three physical property data in the method of the present invention promptly can reflect defoaming property well, also can show its foaming property, that is to say this method can simultaneously carry out the defoaming property and foaming property of test solution test;

(8) Foaming time, foam volume and defoaming time have been accurately recorded in the test method of the present invention, and these data can accurately reflect the degree of foaming and defoaming of test solution, thereby can be in degree Make precise comparisons.

In a word, by using the dynamic anti-foaming and defoaming test method of the present invention, the anti-foaming and defoaming properties of water-based processing fluids can be evaluated more closely to actual working conditions and more accurately according to actual working conditions; In terms of processing fluid foam evaluation, the method of the present invention is a relatively accurate method, so it is meaningful to popularize it in the industry.

The above is only a preferred embodiment of the present invention, it should be pointed out that, for those of ordinary skill in the art, without departing from the principle of the present invention, some improvements and modifications can also be made, and these improvements and modifications can also be made. It should be regarded as the protection scope of the present invention.

Claims (6)

1. an antifoam property method of testing, comprises the following steps:

1., at internal diameter 20mm～100mm, in the cuvette that volume is 2200ml～3500ml, add in advance liquid 800ml～1200ml to be measured;

2., apart from step 1. in liquid level be 30cm～80cm place, by 2L/min～12L/min flow velocity, inject straight down liquid to be measured, produce foam, liquid to be measured flows out by identical speed from test tube bottom simultaneously;

2. step injects the centre of the position of liquid to be measured in liquid level;

When foam generates 1000ml, record spent time; Or

When spent time is the not enough 1000ml of 150min and foam generated, foam volume and spent time that record generates.

2. antifoam property method of testing as claimed in claim 1, is characterized in that: spent time while recording the every generation of foam 100ml.

3. an antifoam performance method of testing, comprises the following steps:

, at internal diameter 20mm～100mm, in the transparent straight pipe that volume is 2200ml～3500ml, add in advance liquid 800ml～1200ml to be measured;

, apart from step (1) in liquid level be 30cm～80cm place, by 2L/min～12L/min flow velocity, inject straight down liquid to be measured, produce foam, liquid to be measured flows out by identical speed from test tube bottom simultaneously;

(2) step injects the centre of the position of liquid to be measured in liquid level;

, step process (2) maintains 80min～100min, stop to test tube, injecting liquid to be measured and flowing out liquid to be measured from test tube, spent time while recording the every cancellation 100ml of foam simultaneously;

When foam cancellation to volume is 40ml, record spent time; Or

When foam generated volume is less than 40ml, until foam volume cancellation is to 0ml, record spent time.

4. a foam performance test device, it is characterized in that: this device comprises pump, the valve being connected successively by circulating line and the transparent straight pipe vertically arranging, described transparent straight pipe internal diameter is 20mm～100mm, and volume is 2200ml～3500ml, and adds in advance liquid 800ml～1200ml to be measured; The pipe outlet that described transparent straight pipe upper end connects is 30cm～80cm apart from liquid level in transparent straight pipe; The flow velocity that described valve is controlled liquid to be measured in pipeline is 2L/min～12L/min;

The pipe outlet that described transparent straight pipe upper end connects be positioned at transparent straight pipe liquid level centre directly over.

5. foam performance test device as claimed in claim 4, is characterized in that: this device also comprises constant temperature water bath apparatus, and described transparent straight pipe is provided with chuck, and described constant temperature water bath apparatus is communicated with chuck.

6. foam performance test device as claimed in claim 4, is characterized in that: this device also includes flowmeter, and described flowmeter is located in the pipeline between valve and transparent straight pipe.

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