On-line density detection device and detection method for viscous medium

Abstract

The invention discloses an online density detection device and detection method for viscous media, belonging to the field of density detection technology. The device includes a detection cabinet, a control module, a sampling tube, a sampling valve, a fixed volume container, a full volume judgment container, a vacuum valve, a vacuum pump, a first solenoid valve, a second solenoid valve, a first weighing sensor and a second weighing sensor, the sampling tube is connected to the bottom of the fixed volume container, the top of the fixed volume container is connected to the bottom of the full volume judgment container through a connecting hose, the top of the full volume judgment container is connected to the vacuum pump through a vacuum tube with a vacuum valve and its upper part or top is connected to the outlet of the second three-way pipe through a hose, the two inlets of the second three-way pipe are respectively connected to the compressed gas supply structure through the pipeline with the first solenoid valve and connected to the cleaning liquid supply structure through the pipeline with the second solenoid valve, and the fixed volume container and the full volume judgment container are respectively suspended on the detection cabinet through the first weighing sensor and the second weighing sensor.

Description

Technical Field

[0001] The present invention belongs to the field of density detection technology, and particularly relates to an online density detection device and detection method for viscous media, especially for online detection of liquids in the process of wet phosphoric acid preparation, including phosphate slurry (density 1.6-1.7g / cm 3 ), concentrated sulfuric acid (density 1.8-1.9g / cm 3 ), wet phosphoric acid (density less than 1.3g / cm 3 ) and lotion (density less than 1.1g / cm 3 ), etc., are all viscous, especially wet-process phosphoric acid and concentrated sulfuric acid. Background Art

[0002] Wet process production is to use inorganic acid to decompose phosphate rock powder, separate crude phosphoric acid, and then purify it to obtain phosphoric acid products. Wet process phosphoric acid is 20%-30% cheaper than thermal process phosphoric acid. After proper purification, the product purity is comparable to thermal process phosphoric acid. Wet process phosphoric acid technology is in a dominant position in phosphoric acid production.

[0003] The production process of wet phosphoric acid is as follows: phosphate rock and phosphogypsum return water are ball-milled, the slurry after ball milling is thickened to obtain phosphate rock slurry of suitable concentration, the phosphate rock slurry is then reacted with concentrated sulfuric acid and back acid (dilute phosphoric acid produced by filtration), and after the reaction is completed, phosphoric acid is filtered to obtain phosphoric acid, which is then concentrated and purified (optional) to obtain phosphoric acid of suitable concentration.

[0004] In the above process, the density of phosphate slurry and phosphoric acid needs to be tested, the density of concentrated sulfuric acid can be tested or not, and the density of washing liquid in the tail gas treatment process (defluorination) in the phosphoric acid preparation process can be tested or not. In the prior art, density testing (weight divided by volume) is usually performed by a density meter (including a test cabinet, a sensor, and a control module, etc.) or by a laboratory; for the density meter testing method, it needs to be recalibrated or directly replaced after a period of time; for the laboratory testing method, it is time-consuming and labor-intensive. Summary of the invention

[0005] In order to solve the above problems, the embodiment of the present invention provides an online density detection device and detection method for viscous medium, which can automatically realize the density measurement of viscous liquid without manual participation, saving time and labor; at the same time, the device measures accurately with an accuracy of up to 0.01g / cm 3 ; The detection time is fast, and the detection and cleaning time can be within 2 minutes; it takes a long time to use (such as two months) before it needs to be proofread. The technical solution is as follows:

[0006] On the one hand, an embodiment of the present invention discloses an online density detection device for viscous media, the device comprising a detection cabinet, a control module in the detection cabinet, a sampling tube 1, a sampling valve on the sampling tube 1, a fixed volume container 2 in the detection cabinet, a full volume judgment container 3, a vacuum valve 4, a vacuum pump 5, a first solenoid valve 8, a second solenoid valve 9, a first weighing sensor 10 and a second weighing sensor 11, the end of the sampling tube 1 is connected to the bottom of the fixed volume container 2, the top of the fixed volume container 2 is connected to the bottom of the full volume judgment container 3 through a connecting hose 6, and the top of the full volume judgment container 3 is connected to the bottom of the full volume judgment container 3 through a vacuum valve 4. The vacuum tube 19 is connected to the vacuum pump 5 and its upper part or top is connected to the outlet of the second three-way pipe 7 through a hose, the two inlets of the second three-way pipe 7 are respectively connected to the compressed gas supply structure through a pipeline with a first solenoid valve 8 and connected to the cleaning liquid supply structure through a pipeline with a second solenoid valve 9, the fixed volume container 2 and the full volume judgment container 3 are respectively suspended on the detection cabinet through the first weighing sensor 10 and the second weighing sensor 11, and the control module is electrically connected to the sampling valve, the first solenoid valve 8, the second solenoid valve 9, the vacuum valve 4, the vacuum pump 5, the first weighing sensor 10 and the second weighing sensor 11.

[0007] Among them, the detection cabinet in the embodiment of the present invention includes a cabinet body 12, a cabinet door on the front side of the cabinet body 12 that can be swung open, and a fixed plate 13 inside the cabinet body 12 and located behind the cabinet door. The fixed plate 13 divides the cabinet body 12 into two cavities arranged side by side in front and back, and its left or right side is rotatably arranged on the corresponding side of the cabinet body 12. Two hollow holes 14 are provided on the fixed plate 13 in the vertical direction. The fixed volume container 2 and the full volume judgment container 3 are both located in front of the fixed plate 13 and are respectively located at the two hollow holes 14. The first weighing sensor 10 and the second weighing sensor 11 are both fixed on the rear side of the fixed plate 13 and pass through the corresponding hollow holes 14.

[0008] Specifically, the first solenoid valve 8 , the second solenoid valve 9 , the vacuum valve 4 and the vacuum pump 5 in the embodiment of the present invention are all arranged on the front side of the fixing plate 13 .

[0009] Furthermore, the control module in the embodiment of the present invention includes a control unit, a touch display screen 15 and a transmitter, wherein the transmitter is arranged on the rear side of the fixed plate 13 and is electrically connected to the first weighing sensor 10 and the second weighing sensor 11, the control unit is arranged on the rear side of the cabinet 12 and is electrically connected to the sampling valve, the first solenoid valve 8, the second solenoid valve 9, the vacuum valve 4, the vacuum pump 5, the touch display screen 15 and the transmitter, and the touch display screen 15 is arranged on the front side of the fixed plate 13.

[0010] Among them, the sampling valve in the embodiment of the present invention includes a third solenoid valve 16 and a pneumatic clamp 17 clamped on the sampling tube 1, the sampling tube 1 is a hose, and a first three-way pipe 18 is provided on the air outlet of the compressed gas supply structure. The two outlets of the first three-way pipe 18 are respectively connected to the pneumatic clamp 17 through a pipeline with the third solenoid valve 16 and connected to the second three-way pipe 7 through a pipeline with the first solenoid valve 8, and the third solenoid valve 16 is electrically connected to the control module.

[0011] Specifically, the fixed volume container 2 and the full volume judgment container 3 in the embodiment of the present invention are both vertically arranged cylindrical glass containers and both of their upper and lower ends are arc-shaped structures. The volume of the fixed volume container 2 is greater than or equal to 50 mL and its upper end is higher than the lower end of the full volume judgment container 3. The connecting hose 6 is first bent downward and then bent upward in an S shape along the liquid delivery direction.

[0012] Among them, the vacuum pump 5 in the embodiment of the present invention is a peristaltic pump, the sampling tube 1, the connecting hose 6 and the vacuum tube 19 are all silicone hoses, the vacuum valve 4 is arranged near the upper end of the full volume judgment container 3, and the vacuum tube 19 is bent downward to form an inverted U shape.

[0013] Specifically, the left side of the fixed plate 13 in the embodiment of the present invention is rotatably arranged on the left side of the cabinet 12, the touch screen 15 is arranged on the upper left side of the fixed plate 13, the third solenoid valve 16 is arranged on the left side of the cabinet 12 and is located in front of the fixed plate 13, the fixed volume container 2 is located below the touch screen 15, the first solenoid valve 8 and the second solenoid valve 9 are both located on the left side of the fixed volume container 2 and are both located below the touch screen 15, the second three-way pipe 7 and the first three-way pipe 18 are both located in front of the fixed plate 13, the full volume judgment container 3 is located on the right side of the fixed volume container 2 and its A third three-way pipe is provided on the top, connecting the upper end of the fixed volume container 2 to the middle part of the full volume judgment container 3, the middle part of the connecting hose 6 is fixed on the fixed plate 13 and connects the fixed volume container 2 and the full volume judgment container 3 in an S shape, the vacuum valve 4 and the vacuum pump 5 are both located on the right side of the full volume judgment container 3, the vacuum pump 5 is located below the vacuum valve 4, and the vacuum valve 4 is located above the full volume judgment container 3; one outlet of the third three-way pipe is connected to the vacuum pipe 19, and the other outlet is connected to the cleaning pipe; the cleaning pipe bypasses the rear side of the fixed plate 13 and is connected to the inlet of the second three-way pipe 7.

[0014] On the other hand, an embodiment of the present invention further provides an online density detection method for viscous liquid, the method comprising:

[0015] (1) Use clean water and / or the liquid to be tested to initially calibrate the online density detection device;

[0016] (2) The first solenoid valve 8, the second solenoid valve 9 and the third solenoid valve 16 are closed, and the vacuum valve 4 and the vacuum pump 5 are opened to suck the liquid to be detected into the constant volume container 2. After the constant volume container 2 is full, the liquid to be detected continues to enter the full volume judgment container 3. When the weight detected by the second weighing sensor 11 reaches the set value, the vacuum valve 4 and the vacuum pump 5 are closed, and the third solenoid valve 16 is opened;

[0017] (3) After a predetermined time, the control module calculates the density of the liquid to be detected based on the detection data of the first weighing sensor 10;

[0018] (4) After the detection is completed, the first solenoid valve 8 or the second solenoid valve 9 is opened to allow compressed air or cleaning liquid to be delivered to the liquid to be detected in the fixed volume container 2 and the full volume judgment container 3;

[0019] (5) opening and closing the first solenoid valve 8, the second solenoid valve 9 and / or the third solenoid valve 16 according to a predetermined cleaning strategy to clean the online density detection device;

[0020] The cleaning liquid is selected from normal temperature water, hot water, normal temperature water with a cleaning agent, hot water with a cleaning agent or high temperature steam, and the pressure of the compressed air is greater than 0.2 MPa.

[0021] Among them, step (5) specifically includes two solutions:

[0022] Scheme 1: After the detection is completed, the second solenoid valve 9 is opened to pass the cleaning liquid. After a period of time, the first solenoid valve 8 is opened and the second solenoid valve 9 is closed to pass the compressed air. The above process is repeated at least twice. Except for the first time of passing the cleaning liquid, the third solenoid valve 16 is opened each time the cleaning liquid is passed, and the third solenoid valve 16 is closed after a period of time. The time for passing the cleaning liquid is gradually reduced, and the time for passing the compressed air is gradually increased.

[0023] Option 2, after the detection is completed, open the second solenoid valve 9 to pass the cleaning liquid, and after a period of time, close the second solenoid valve 9; then open the second solenoid valve 9 and the third solenoid valve 16, and after a period of time, close the second solenoid valve 9 and the third solenoid valve 16, and repeat the above process at least twice; finally, open the first solenoid valve 8 and close the second solenoid valve 9 to pass compressed air.

[0024] The technical solution provided by the embodiment of the present invention has the following beneficial effects: the embodiment of the present invention provides an online density detection device and detection method for viscous medium, which can automatically realize the density measurement of viscous liquid without manual participation, saving time and labor; at the same time, the device measures accurately with an accuracy of up to 0.01g / cm 3; The detection time is fast, and the detection and cleaning time can be within 2 minutes; it takes a long time to use (such as two months) before calibration. The device is also convenient for online detection and easy to clean automatically. In addition, this patent also has the advantage of wide adaptability. The control module can be programmed to adjust the detection process and cleaning process, and the sampling frequency can also be adjusted. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a principle block diagram of an online density detection device for viscous media in an embodiment of the present invention;

[0026] Figure 2 is a circuit connection diagram of a control module in an embodiment of the present invention;

[0027] Figure 3 It is a partial structural schematic diagram of an online density detection device for viscous media in an embodiment of the present invention.

[0028] In the figure: 1 sampling tube, 2 fixed volume container, 3 full volume judgment container, 4 vacuum valve, 5 vacuum pump, 6 connecting hose, 7 second three-way pipe, 8 first solenoid valve, 9 second solenoid valve, 10 first weighing sensor, 11 second weighing sensor, 12 cabinet, 13 fixing plate, 14 hollow hole, 15 touch display screen, 16 third solenoid valve, 17 pneumatic clamp, 18 first three-way pipe, 19 vacuum tube. DETAILED DESCRIPTION

[0029] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention will be further described in detail below with reference to the accompanying drawings.

[0030] Example 1

[0031] See also Figure 1-3, Embodiment 1 discloses an online density detection device for viscous media, which includes a detection cabinet (which can be set up on site or in a monitoring room), a sampling tube 1 (the beginning of which is connected to the storage container or delivery pipeline of the liquid to be detected, and a three-way tube can be set on it (optionally, the liquid after detection returns to the liquid system to be detected, and the washing liquid is output to the waste water bucket). If not set, it returns to the liquid system to be detected), a sampling valve on the sampling tube 1 and a control module in the detection cabinet, a fixed volume container 2 (with a fixed volume), a full volume judgment container 3 (used to judge whether the fixed volume container 2 is full), a vacuum valve 4, a vacuum pump 5 (used to make the liquid to be detected flow), a first solenoid valve 8, a second solenoid valve 9, a first weighing sensor 10 and a second weighing sensor 11, etc. Among them, the end of the sampling tube 1 is connected to the bottom of the fixed volume container 2, and the top of the fixed volume container 2 is connected to the bottom of the full volume judgment container 3 through a connecting hose 6; only when the fixed volume container 2 is full, the liquid to be detected can enter the full volume judgment container 3. The top of the full volume judgment container 3 is connected to the vacuum pump 5 through a vacuum tube 19 with a vacuum valve 4, and its upper part or top is connected to the outlet of the second three-way pipe 7 through a hose to allow the clear liquid and compressed air to enter. The two inlets of the second three-way pipe 7 are respectively connected to the compressed gas supply structure (used to provide compressed air, which can be an air compressor or a gas storage tank) through a pipeline with a first electromagnetic valve 8 and connected to the cleaning liquid supply structure (used to provide cleaning liquid, preferably with a certain pressure, which can be a storage tank or a tap water pipe) through a pipeline with a second electromagnetic valve 9. The fixed volume container 2 and the full volume judgment container 3 are respectively suspended on the detection cabinet through the first weighing sensor 10 and the second weighing sensor 11 to realize weight detection. The control module is electrically connected to the sampling valve, the first electromagnetic valve 8, the second electromagnetic valve 9, the vacuum valve 4, the vacuum pump 5, the first weighing sensor 10 and the second weighing sensor 11 to realize automatic control of the device.

[0032] Among them, see Figure 3 The detection cabinet in the embodiment of the present invention includes a cabinet body 12 (specifically, it can be a rectangle), a cabinet door on the front side of the cabinet body 12 that can be swung open, and a fixed plate 13 (specifically, it can be a rectangular plate that matches the cabinet body 12) inside the cabinet body 12 and located behind the cabinet door. The fixed plate 13 divides the cabinet body 12 into two cavities (a front cavity and a rear cavity) arranged side by side in front and back, and it can be rotated on the left or right side (specifically, it can be hinged) and arranged on the corresponding side of the cabinet body 12. Two hollow holes 14 (specifically, they can be vertically arranged rectangular holes) are provided on the fixed plate 13 in the vertical direction. The fixed volume container 2 and the full volume judgment container 3 are both located in front of the fixed plate 13 and are respectively located at the two hollow holes 14. The first weighing sensor 10 and the second weighing sensor 11 are both fixed on the rear side of the fixed plate 13 (specifically, fixed on the left or right side of the corresponding hollow hole 14) and are fixedly connected to the fixed volume container 2 and the full volume judgment container 3 through the corresponding hollow holes 14.

[0033] Specifically, see Figure 3 In the embodiment of the present invention, the first solenoid valve 8 , the second solenoid valve 9 , the vacuum valve 4 and the vacuum pump 5 are all arranged on the front side of the fixed plate 13 .

[0034] Further, see Figure 2 and 3 The control module in the embodiment of the present invention includes a control unit (specifically including a PLC and its associated circuits), a touch screen 15 and a transmitter (equipped with a first weighing sensor 10 and a second weighing sensor 11 for data processing of weighing data), etc. The transmitter is arranged at the rear side of the fixed plate 13 and is electrically connected to the first weighing sensor 10 and the second weighing sensor 11. The control unit is arranged at the rear side of the cabinet 12 and is electrically connected to the sampling valve, the first solenoid valve 8, the second solenoid valve 9, the vacuum valve 4, the vacuum pump 5, the touch screen 15 and the transmitter. The touch screen 15 is arranged at the front side of the fixed plate 13. Specifically, the control unit includes a Siemens SMART control module, the touch screen 15 is a touch screen produced by MCGS, the transmitter is a DY510 transmitter, and the first weighing sensor 10 and the second weighing sensor 11 are loadcell8610 (upper limit is 300g, accuracy is 0.01g).

[0035] Among them, see Figure 1-3 The sampling valve in the embodiment of the present invention includes a third solenoid valve 16 and a pneumatic clamp 17 clamped on the sampling tube 1 (when it is opened, the sampling tube 1 is clamped to prevent the liquid from flowing). The sampling tube 1 is a hose. The outlet of the compressed gas supply structure is provided with a first three-way pipe 18. The two outlets of the first three-way pipe 18 are respectively connected to the pneumatic clamp 17 through a pipeline with the third solenoid valve 16 and connected to an inlet of the second three-way pipe 7 through a pipeline with the first solenoid valve 8. The third solenoid valve 16 is electrically connected to the control module. In this patent, the pneumatic clamp 17 is used to control the sampling tube 1, which can ensure that the liquid does not flow during the detection to ensure the accuracy of the detection.

[0036] Specifically, see Figure 3 The fixed volume container 2 and the full volume judgment container 3 in the embodiment of the present invention are both vertically arranged columnar glass containers and both of their upper and lower ends are arc-shaped structures. The volume of the fixed volume container 2 (specifically, it can be 250mL) is greater than or equal to 50mL and its upper end is higher than the lower end of the full volume judgment container 3. The connecting hose 6 is first bent downward and then bent upward in an S shape along the liquid delivery direction. The fixed volume container 2 and the full volume judgment container 3 can also be made of other materials, which are required to be corrosion-resistant, and also need to avoid the liquid to be detected from hanging on the wall, and also need to be easy to clean. Common glass containers are usually used.

[0037] Among them, the vacuum pump 5 in the embodiment of the present invention is a peristaltic pump, the sampling tube 1, the connecting hose 6 and the vacuum tube 19 are all silicone hoses (can also be other materials, requiring corrosion resistance and long service life), the vacuum valve 4 is arranged near the upper end of the full volume judgment container 3, and the vacuum tube 19 is bent downward to form an inverted U shape.

[0038] Specifically, see Figure 3 The left side of the fixed plate 13 in the embodiment of the present invention is rotatably arranged on the left side of the cabinet 12, the touch screen 15 is arranged on the upper left side of the fixed plate 13, the third solenoid valve 16 is arranged on the left side of the cabinet 12 and in front of the fixed plate 13, and the pneumatic clamp 17 is arranged on the lower side of the cabinet 12. The fixed volume container 2 is located below the touch screen 15, the first solenoid valve 8 and the second solenoid valve 9 (the first solenoid valve 8 and the second solenoid valve 9 can be arranged side by side) are both located on the left side of the fixed volume container 2 and below the touch screen 15, and the second three-way pipe 7 and the first three-way pipe 18 are both located in front of the fixed plate 13. The full volume judgment container 3 is located on the right side of the fixed volume container 2 and a third three-way pipe is arranged on the top of the fixed volume container 2, from the upper end of the fixed volume container 2 to the middle of the full volume judgment container 3. The middle part of the connecting hose 6 is fixed on the fixed plate 13 and it connects the fixed volume container 2 and the full volume judgment container 3 in an S shape. The vacuum valve 4 and the vacuum pump 5 are both located on the right side of the full volume judgment container 3, the vacuum pump 5 is located below the vacuum valve 4, and the vacuum valve 4 is located above the full volume judgment container 3. One outlet of the third three-way pipe is connected to the vacuum pipe 19, and the other outlet (located at the rear side) is connected to the cleaning pipe. The cleaning pipe bypasses the rear side of the fixed plate 13 (on which a through hole for the cleaning pipe to pass through) and is connected to the inlet of the second three-way pipe 7.

[0039] Example 2

[0040] Embodiment 2 provides an online density detection method for viscous liquids, which adopts the online density detection device for viscous media disclosed in Embodiment 1. The method comprises:

[0041] (1) Use clean water and / or the liquid to be tested to initially calibrate the online density detection device. Specifically, the device can be calibrated three times with clean water and / or the liquid to be tested, and then the average value is taken; when water is used for calibration, the density of water is 1.00 g / cm 3 When the liquid to be tested is used for calibration, the density of the liquid to be tested is measured in the laboratory (volume is measured by a volumetric flask and mass is measured by an analytical balance).

[0042] (2) Close the first electromagnetic valve 8, the second electromagnetic valve 9 and the third electromagnetic valve 16, open the vacuum valve 4 and the vacuum pump 5, and suck the liquid to be detected into the constant volume container 2. After the constant volume container 2 is full, the liquid to be detected continues to enter the full volume judgment container 3. When the weight detected by the second weighing sensor 11 reaches the set value, close the vacuum valve 4 and the vacuum pump 5, and open the third electromagnetic valve 16. In this step, the liquid level of the full volume judgment container 3 reaches the middle (which can be set as needed) and the liquid level therein is preferably higher than the top of the constant volume container 2.

[0043] (3) After a predetermined time (e.g., 30 seconds after the third solenoid valve 16 is closed), the control module calculates the density of the liquid to be tested based on the detection data of the first weighing sensor 10 (by dividing the weight by the volume of the fixed volume container 2 and calibrating it according to the result of step (1)). In this step, multiple weight data obtained by the first weighing sensor 10 within 5 seconds can be selected and the average value can be taken.

[0044] (4) After the detection is completed, the first solenoid valve 8 or the second solenoid valve 9 is opened to allow compressed air or cleaning liquid to be introduced to send the liquid to be detected in the fixed volume container 2 and the full volume judgment container 3 out (to the liquid system to be detected or the waste water bucket). This step is also equivalent to a cleaning step.

[0045] (5) Opening and closing the first solenoid valve 8, the second solenoid valve 9 and / or the third solenoid valve 16 according to a predetermined cleaning strategy to clean the online density detection device.

[0046] The cleaning liquid is selected from normal temperature water, hot water, normal temperature water with cleaning agent, hot water with cleaning agent or high temperature steam (selected according to the liquid to be detected), the pressure of compressed air is greater than 0.2 MPa, and the pressure of the cleaning liquid is preferably greater than 0.5 MPa. After the online density detection device for viscous media has been used for a period of time, it can be calibrated by the method of step (1), usually after about 2 months of use.

[0047] Among them, step (5) specifically includes two solutions:

[0048] Solution 1: After the detection is completed, the second solenoid valve 9 is opened to pass the cleaning liquid. After a period of time, the first solenoid valve 8 is opened and the second solenoid valve 9 is closed to pass the compressed air. The above process is repeated at least twice. Except for the first time of passing the cleaning liquid, the third solenoid valve 16 is opened each time the cleaning liquid is passed, and the third solenoid valve 16 is closed after a period of time. The time for passing the cleaning liquid is gradually reduced, and the time for passing the compressed air is gradually increased. Specifically, the total time for passing the cleaning liquid and compressed air each time is less than 30 seconds.

[0049] Option 2, after the detection is completed, open the second solenoid valve 9 to pass the cleaning liquid, and after a period of time, close the second solenoid valve 9; then open the second solenoid valve 9 and the third solenoid valve 16, and after a period of time, close the second solenoid valve 9 and the third solenoid valve 16, and repeat the above process at least twice; finally, open the first solenoid valve 8 and close the second solenoid valve 9 to pass compressed air.

[0050] The effect of the online density detection device disclosed in this patent is verified as follows:

[0051] Table 1 shows the density of the slurry (tested every ten minutes, the result of the laboratory test is 1.642-1.646 g / cm 3 ), Table 2 shows the density of concentrated sulfuric acid (tested every five minutes, the result of laboratory test is 1.831-1.834 g / cm 3 ), Table 3 shows the density of the finished phosphoric acid (tested every five minutes, the result of the laboratory test is 1.112-1.116 g / cm 3 ), Table 4 shows the density test of intermediate phosphoric acid (unpurified and unblended phosphoric acid) (tested every five minutes, the result of laboratory test is 1.271-1.275 g / cm 3 ).

[0052] Table 1

[0053]

[0054] Table 2

[0055]

[0056] Table 3

[0057]

[0058] Table 4

[0059]

[0060] It can be seen from Tables 1-4 that the measurement results of phosphate slurry, sulfuric acid and phosphoric acid by this device are very stable and similar to the results of laboratory tests.

[0061] Table 5 shows the density measurement of the slurry at regular intervals (5 days or 6 days), using this device, the test method and the density meter (ZY-02) for measurement. On April 5, 2021, a new density meter was used and this device had just been debugged.

[0062] Table 5

[0063]

[0064] As can be seen from Table 5, the test results of the patent within 60 days are very accurate and are not much different from the test results of the experimental method (usually within 0.003g / cm 3 After proofreading, the test results are not much different from those of the experimental method.

[0065] In summary, the device has the advantages of accurate detection results and maintaining accurate measurements for a long time.

[0066] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An online density detection device for viscous media, comprising a detection cabinet and a control module therein; characterized in that: The invention also comprises a sampling tube (1), a sampling valve on the sampling tube (1), a fixed volume container (2) in a detection cabinet, a full volume judgment container (3), a vacuum valve (4), a vacuum pump (5), a first electromagnetic valve (8), a second electromagnetic valve (9), a first weighing sensor (10) and a second weighing sensor (11); the end of the sampling tube (1) is connected to the bottom of the fixed volume container (2); the top of the fixed volume container (2) is connected to the bottom of the full volume judgment container (3) through a connecting hose (6); the top of the full volume judgment container (3) is connected to the vacuum pump (5) through a vacuum tube (19) with a vacuum valve (4), and the upper part or the lower part of the full volume judgment container (3) is connected to the vacuum pump (5). The top is connected to the outlet of the second three-way pipe (7) through a hose, and the two inlets of the second three-way pipe (7) are respectively connected to the compressed gas supply structure through a pipeline with a first electromagnetic valve (8) and connected to the cleaning liquid supply structure through a pipeline with a second electromagnetic valve (9), the fixed volume container (2) and the full volume judgment container (3) are respectively suspended on the detection cabinet through a first weighing sensor (10) and a second weighing sensor (11), and the control module is electrically connected to the sampling valve, the first electromagnetic valve (8), the second electromagnetic valve (9), the vacuum valve (4), the vacuum pump (5), the first weighing sensor (10) and the second weighing sensor (11); The fixed volume container (2) and the full volume judgment container (3) are both vertically arranged cylindrical glass containers and both of their upper and lower ends are arc-shaped structures. The volume of the fixed volume container (2) is greater than or equal to 50 mL and its upper end is higher than the lower end of the full volume judgment container (3). The connecting hose (6) is first bent downward and then bent upward in an S-shape along the liquid conveying direction. The vacuum pump (5) is a peristaltic pump, the sampling tube (1), the connecting hose (6) and the vacuum tube (19) are all silicone hoses, the vacuum valve (4) is arranged near the upper end of the full volume judgment container (3), and the vacuum tube (19) is bent downward to form an inverted U shape.

2. The online density detection device for viscous media according to claim 1, characterized in that: The detection cabinet comprises a cabinet body (12), a cabinet door on the front side of the cabinet body (12) that can be rotated, and a fixed plate (13) located inside the cabinet body (12) and behind the cabinet door; the fixed plate (13) divides the cabinet body (12) into two cavities arranged side by side in front and back, and the left side or right side of the fixed plate (13) is rotatably arranged on the corresponding side of the cabinet body (12); two hollow holes (14) are arranged on the fixed plate (13) in the vertical direction; the fixed volume container (2) and the full volume judgment container (3) are both located in front of the fixed plate (13) and are respectively located at the two hollow holes (14); the first weighing sensor (10) and the second weighing sensor (11) are both fixed on the rear side of the fixed plate (13) and pass through the corresponding hollow holes (14).

3. The online density detection device for viscous media according to claim 2, characterized in that: The first solenoid valve (8), the second solenoid valve (9), the vacuum valve (4) and the vacuum pump (5) are all arranged on the front side of the fixed plate (13).

4. The online density detection device for viscous media according to claim 3, characterized in that: The control module comprises a control unit, a touch display screen (15) and a transmitter, wherein the transmitter is arranged at the rear side of the fixed plate (13) and is electrically connected to the first weighing sensor (10) and the second weighing sensor (11), the control unit is arranged at the rear side of the cabinet (12) and is electrically connected to the sampling valve, the first solenoid valve (8), the second solenoid valve (9), the vacuum valve (4), the vacuum pump (5), the touch display screen (15) and the transmitter, and the touch display screen (15) is arranged at the front side of the fixed plate (13).

5. The on-line density detection device for viscous medium according to claim 4, characterized in that: The sampling valve comprises a third solenoid valve (16) and a pneumatic clamp (17) clamped on a sampling tube (1); the sampling tube (1) is a hose; a first three-way pipe (18) is provided on the gas outlet of the compressed gas supply structure; two outlets of the first three-way pipe (18) are respectively connected to the pneumatic clamp (17) through a pipeline with the third solenoid valve (16) and to the second three-way pipe (7) through a pipeline with the first solenoid valve (8); the third solenoid valve (16) is electrically connected to a control module.

6. The on-line density detection device for viscous media according to claim 5, characterized in that: The left side of the fixed plate (13) is rotatably arranged on the left side of the cabinet (12); the touch screen (15) is arranged on the upper left side of the fixed plate (13); the third solenoid valve (16) is arranged on the left side of the cabinet (12) and is located in front of the fixed plate (13); the fixed volume container (2) is located below the touch screen (15); the first solenoid valve (8) and the second solenoid valve (9) are both located on the left side of the fixed volume container (2) and are both located below the touch screen (15); the second three-way pipe (7) and the first three-way pipe (18) are both located in front of the fixed plate (13); the full volume judgment container (3) is located on the right side of the fixed volume container (2) and is provided with a A third three-way pipe is provided, which connects the upper end of the fixed volume container (2) to the middle of the full volume judgment container (3); the middle of the connecting hose (6) is fixed on the fixed plate (13) and connects the fixed volume container (2) and the full volume judgment container (3) in an S shape; the vacuum valve (4) and the vacuum pump (5) are both located on the right side of the full volume judgment container (3); the vacuum pump (5) is located below the vacuum valve (4); and the vacuum valve (4) is located above the full volume judgment container (3); one outlet of the third three-way pipe is connected to the vacuum pipe (19), and the other outlet thereof is connected to the cleaning pipe; the cleaning pipe bypasses the rear side of the fixed plate (13) and is connected to the inlet of the second three-way pipe (7).

7. A density detection method using the online density detection device for viscous media as claimed in claim 5, characterized in that: The method comprises: (1) Use clean water and / or the liquid to be tested to initially calibrate the online density detection device; (2) the first electromagnetic valve (8), the second electromagnetic valve (9) and the third electromagnetic valve (16) are closed, the vacuum valve (4) and the vacuum pump (5) are opened, and the liquid to be detected is sucked into the constant volume container (2). After the constant volume container (2) is filled, the liquid to be detected continues to enter the full volume judgment container (3). When the weight detected by the second weighing sensor (11) reaches a set value, the vacuum valve (4) and the vacuum pump (5) are closed, and the third electromagnetic valve (16) is opened; (3) After a predetermined time, the control module calculates the density of the liquid to be detected based on the detection data of the first weighing sensor (10); (4) After the detection is completed, the first solenoid valve (8) or the second solenoid valve (9) is opened to allow compressed air or cleaning liquid to be introduced to send out the liquid to be detected in the fixed volume container (2) and the full volume judgment container (3); (5) opening and closing the first solenoid valve (8), the second solenoid valve (9) and / or the third solenoid valve (16) according to a predetermined cleaning strategy to clean the online density detection device; The cleaning liquid is selected from normal temperature water, hot water, normal temperature water with a cleaning agent, hot water with a cleaning agent or high temperature steam, and the pressure of the compressed air is greater than 0.2 MPa.

8. The density detection method according to claim 7, characterized in that: Step (5) specifically includes two solutions: Solution 1: After the detection is completed, the second solenoid valve (9) is opened to allow the cleaning liquid to pass through. After a period of time, the first solenoid valve (8) is opened and the second solenoid valve (9) is closed to allow the compressed air to pass through. Repeat the above process at least twice, except for the first time when the cleaning liquid is introduced, the third solenoid valve (16) is opened each time the cleaning liquid is introduced, and the third solenoid valve (16) is closed after a period of time; the time for introducing the cleaning liquid is gradually reduced, and the time for introducing the compressed air is gradually increased; Solution 2: After the detection is completed, the second solenoid valve (9) is opened to allow the cleaning liquid to pass through. After a period of time, the second solenoid valve (9) is closed; the second solenoid valve (9) and the third solenoid valve (16) are opened again. After a period of time, the second solenoid valve (9) and the third solenoid valve (16) are closed, and the above process is repeated at least twice; finally, the first solenoid valve (8) is opened and the second solenoid valve (9) is closed to allow the compressed air to pass through.

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