Non-radiation-source non-contact type fluid on-line density measuring method

Abstract

The invention relates to a radiation-source-free non-contact fluid on-line density measurement method, which belongs to the technical field of fluid density measurement, and comprises the following operation steps of: 1, generating a small pressure difference through a pressure difference generator, so that a height difference is generated between liquid in a measurement tube and liquid in a to-be-measured liquid container; 2, recording a pressure value P1 in the measuring tube through a pressure sensor I; and the pressure value P0 in the liquid container to be measured is recorded through the pressure sensor II. And 3, measuring the height H1 from the liquid level in the measuring tube to the upper end face of the measuring tube by taking the upper end face of the measuring tube as a reference, and measuring the height H0 from the liquid level in the to-be-measured liquid container to the upper end face of the measuring tube. And 4, calculating the density of the liquid in the container according to the real-time pressure difference value and the real-time height difference value. The device has the advantages of simple structure, convenience in operation and application, high measurement stability and accurate measurement precision. And meanwhile, the problem of measuring the density of corrosive fluid or fluid which is not suitable for being in direct contact with a measuring component is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of fluid density measurement, and in particular to a radiation-free non-contact fluid online density measurement method. Background Art

[0002] Traditionally, liquid density is measured using a graduated cylinder and a balance. Liquid is removed from a container, added to a graduated cylinder, and its volume is measured. The mass is then weighed, and the density of the liquid is calculated or converted. Prior art liquid density measuring instruments have been developed that can be connected to a computer for network control and real-time monitoring of liquid density changes. For example, the "Intelligent Liquid Densitometer," disclosed in Chinese Invention Patent Application No. 200410036789.2, utilizes the principle that liquid density is proportional to pressure. This instrument includes a pressure transmitter, a safety barrier, and a control and display circuit. The pressure transmitter is electrically connected to the intrinsically safe side of the safety barrier.

[0003] The prior art, "Integrated Fluid Density Detection Instrument," application number CN200720188314.4, discloses a device comprising a high-pressure side flange, a low-pressure side flange, a high-pressure side capillary tube, a pressure sensor, and a processing unit. It is characterized by a support rod fastening the high-pressure side flange to the low-pressure side flange, maintaining a distance between the high-pressure side flange and the low-pressure side flange, and a pressure sensor and processing unit mounted on the support rod. Existing densitometers can only measure the density of solutions with relatively ideal properties. They are unable to detect widely used fluids, such as solid-liquid mixtures, viscous, easily hardened, corrosive organic and inorganic fluids, or provide inaccurate test data with significant errors.

[0004] Traditional pipeline fluid density measuring devices are generally divided into pipeline type, immersion type, volumetric type or radial type.

[0005] In-line density measurement systems connect a density meter in series with the liquid flow pipe. When the fluid flows through the density meter for density measurement, impurities in the fluid can easily become trapped inside the meter, preventing the fluid from flowing through the system. Furthermore, some in-line density measurement devices are not suitable for liquids containing solids or gases. Furthermore, the density meter frequently becomes clogged by impurities in the slurry. Each attempt to clear the clog requires unfastening the front and rear flanges of the density meter and flushing with water, a time-consuming and labor-intensive process. Furthermore, safety considerations require a work permit, often significantly impacting operators' ability to monitor the slurry density.

[0006] Immersed sensing elements are immersed in the measured solution and are easily disturbed by the liquid, which can lead to increased errors. They are not suitable for viscous, hardened, or solid-containing liquids. They also have high requirements for liquid volume and cannot accurately measure small amounts of solution. In addition, the sensing element is sensitive to vibration, which can easily lead to large errors.

[0007] Volumetric measurement methods mainly rely on the inherent volume and mass of the container. This type of method also has high requirements for the container volume and weighing sensor. It has great difficulties in continuous measurement and online measurement, and has high requirements for the precipitation and compaction of the solution.

[0008] Reflective density measurement can adapt to a wider range of application scenarios, but the calibration is complex, the radiation source control requirements are extremely high, and some liquids to be measured may be contaminated. It also has extremely high requirements for personnel and has a certain impact on the environment. Summary of the Invention

[0009] The present invention primarily addresses the deficiencies in the prior art by providing a sourceless, non-contact, online fluid density measurement method. This method utilizes air or an inert gas to transmit a pressure differential, maintaining a non-contact state between the pressure detection component and the liquid being measured. This ensures that the measured medium is not contaminated while protecting the measuring component, ensuring continuous density measurement of corrosive or abrasive fluids that are not suitable for direct contact. The method has the advantages of a simple structure, convenient operation, high measurement stability, and accurate measurement accuracy. It also addresses the density measurement issues of corrosive, highly disturbed, and easily hardened and precipitated solid-gas-liquid multiphase fluids, or fluids that are not suitable for direct contact with the measuring component.

[0010] The above technical problems of the present invention are mainly solved by the following technical solutions:

[0011] A source-free, contactless, online density measurement method for fluids. The online density measurement device includes a liquid container to be measured, a measuring tube provided on the liquid container with a gap reserved from the bottom of the liquid container to be measured, a pressure differential generator connected to the measuring tube provided at the upper end of the measuring tube, a pressure sensor I provided on the upper inner side of the measuring tube for monitoring the pressure in the measuring tube cavity, and a pressure sensor II provided on the upper outer side of the measuring tube for monitoring the pressure in the liquid container to be measured.

[0012] The measurement method includes the following steps:

[0013] Step 1: Generate a small pressure difference through the pressure differential generator, so that there is a height difference between the liquid in the measuring tube and the liquid in the liquid container to be measured.

[0014] Step 2: Record the pressure value P1 in the measuring tube through pressure sensor I; record the pressure value P0 in the liquid container to be measured through pressure sensor II.

[0015] Step 3: Using the upper end face of the measuring tube as a reference, measure the height from the liquid level in the measuring tube to the upper end face of the measuring tube as H1, and measure the height from the liquid level in the liquid container to be measured to the upper end face of the measuring tube as H0.

[0016] Step 4: Calculate the density of the liquid in the container through the real-time pressure difference value and the real-time height difference value.

[0017] As a preference, when the pressure difference generator is negative pressure or positive pressure, the calculation formula is: g is the acceleration due to gravity.

[0018] Preferably, the pressure difference is transmitted by air or inert gas so that the pressure sensors I and II are not in contact with the measured liquid, and the density of corrosive fluids or abrasive liquids that are not suitable for direct contact can be continuously measured.

[0019] The present invention can achieve the following effects:

[0020] The present invention provides a source-free, non-contact, online fluid density measurement method. Compared with existing technologies, it offers the advantages of simple structure, convenient operation, high measurement stability, and accurate measurement accuracy. It also addresses the problem of measuring the density of corrosive fluids or fluids that are not suitable for direct contact with the measuring components. By using air or an inert gas to transmit a pressure differential, the pressure detection component and the measured liquid are kept out of contact, ensuring that the measured medium is not contaminated while protecting the measuring components, enabling continuous density measurement of corrosive or abrasive fluids that are not suitable for direct contact. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural schematic diagram of the present invention under negative pressure state.

[0022] Figure 2 It is a structural schematic diagram of the present invention under positive pressure state.

[0023] In the figure: measuring tube 1, differential pressure generator 2, pressure sensor I 3, pressure sensor II 4, and container for liquid to be measured 5. DETAILED DESCRIPTION

[0024] The technical solution of the invention is further described in detail below through embodiments and in conjunction with the accompanying drawings.

[0025] Example: Figure 1 and Figure 2 As shown, a source-free, non-contact, online density measurement method for a fluid is provided. The online density measurement device includes a liquid container 5 to be measured, a measuring tube 1 provided on the liquid container 5 with a gap reserved from the bottom of the liquid container 5, a pressure differential generator 2 connected to the measuring tube 1 provided at the upper end of the measuring tube 1, a pressure sensor I 3 for monitoring the cavity pressure of the measuring tube 1 provided on the upper inner side of the measuring tube 1, and a pressure sensor II 4 for monitoring the cavity pressure of the liquid container 5 provided on the upper outer side of the measuring tube 1.

[0026] The measurement method includes the following steps:

[0027] Step 1: A small pressure difference is generated by the pressure differential generator 2, so that a height difference is generated between the liquid in the measuring tube 1 and the liquid in the liquid container 5 to be measured.

[0028] Step 2: Record the pressure value P1 in the measuring tube 1 through the pressure sensor I 3; record the pressure value P0 in the liquid container 5 to be measured through the pressure sensor II 4.

[0029] Step 3: With the upper end surface of the measuring tube 1 as a reference, measure the height from the liquid level in the measuring tube 1 to the upper end surface of the measuring tube 1 as H1, and measure the height from the liquid level in the liquid container 5 to the upper end surface of the measuring tube 1 as H0.

[0030] Step 4: Calculate the density of the liquid in the container through the real-time pressure difference value and the real-time height difference value.

[0031] When the differential pressure generator 2 is negative pressure or positive pressure, the calculation formula is: g is the acceleration due to gravity. By using air or an inert gas to transmit the pressure differential, pressure sensors I 3 and II 4 are kept out of contact with the liquid being measured. This allows for continuous density measurement of corrosive or abrasive fluids that are not suitable for direct contact.

[0032] In summary, this sourceless, non-contact, online fluid density measurement method offers the advantages of simple structure, convenient operation, high measurement stability, and accurate measurement accuracy. It also addresses the challenge of measuring the density of corrosive fluids or fluids that are not suitable for direct contact with the measuring components. By utilizing air or an inert gas to transmit the pressure differential, the pressure sensing component and the measured liquid are kept out of contact, ensuring that the measured medium is not contaminated while protecting the measuring components, enabling continuous density measurement of corrosive or abrasive fluids that are not suitable for direct contact.

[0033] The above description is only a specific embodiment of the present invention, but the structural features of the present invention are not limited thereto. Any changes or modifications made by any technician in this field within the scope of the present invention are included in the patent scope of the present invention.

Claims

1. A source-free, non-contact method for measuring the online density of a fluid, characterized by: The online density measuring device comprises a liquid container (5) to be measured, the liquid container (5) to be measured is provided with a measuring tube (1) with a gap reserved with the bottom of the liquid container (5) to be measured, the upper end of the measuring tube (1) is provided with a pressure difference generator (2) connected to the measuring tube (1), the upper inner portion of the measuring tube (1) is provided with a pressure sensor I (3) for monitoring the cavity pressure of the measuring tube (1), and the upper outer portion of the measuring tube (1) is provided with a pressure sensor II (4) for monitoring the cavity pressure of the liquid container (5) to be measured; The measurement method includes the following steps: Step 1: A small pressure difference is generated by a pressure differential generator (2) so that a height difference is generated between the liquid in the measuring tube (1) and the liquid in the liquid container (5) to be measured; Step 2: Record the pressure value P1 in the measuring tube (1) through the pressure sensor I (3); record the pressure value P0 in the liquid container (5) to be measured through the pressure sensor II (4); Step 3: Using the upper end surface of the measuring tube (1) as a reference, measure the height H1 from the liquid level in the measuring tube (1) to the upper end surface of the measuring tube (1), and measure the height H0 from the liquid level in the liquid container (5) to the upper end surface of the measuring tube (1); Step 4: Calculate the density of the liquid in the container through the real-time pressure difference value and the real-time height difference value.

2. The source-free, non-contact, on-line fluid density measurement method according to claim 1, wherein: When the pressure difference generator (2) is negative pressure or positive pressure, the calculation formula is: g is the acceleration due to gravity.

3. The source-free, contactless, on-line fluid density measurement method according to claim 1 or 2, characterized in that: By using air or inert gas to transmit pressure difference, the pressure sensor I (3) and the pressure sensor II (4) are placed in a non-contact state with the measured liquid, and the density of corrosive fluids or abrasive liquids that are not suitable for direct contact can be continuously measured.

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