阅读说明：本技术 一种用于测量粘稠液体分界面的液位浮标 (Liquid level buoy for measuring interface of viscous liquid ) 是由 田中山 杨昌群 牛道东 李育特 朱航宇 唐志峰 陈会明 于 2021-07-02 设计创作，主要内容包括：本发明公开了一种用于测量粘稠液体分界面的液位浮标。本发明的液位浮标整体关于中心对称,包括匀质腔体和环形磁铁；所述匀质腔体为三维欧几里得几何空间下或三维罗巴切夫斯基几何空间下或三维黎曼几何空间下的任一实体,匀质腔体的中心设置有中心孔洞,液位传感器的测杆穿过中心孔洞后使得液位浮标同轴套装在测杆上；匀质腔体内为匀质环形空腔,匀质环形空腔中嵌入式地安装有环形磁铁。本发明通过减小浮标中心孔洞的边缘厚度,使得浮标与测杆之间重合面积缩小,使浮标在高粘度液体中与测杆做相对运动时粘滞力减小,运动更加自由顺畅。浮标采用匀质空腔,可增大浮力。在中心孔洞处放置一环形磁铁,可为液位传感器提供稳定的磁场。(The invention discloses a liquid level buoy for measuring a viscous liquid interface. The whole liquid level buoy is symmetrical about the center and comprises a homogeneous cavity and an annular magnet; the homogeneous cavity is any entity under a three-dimensional Euclidean geometric space or a three-dimensional Robacco-Techsky geometric space or a three-dimensional Riemann geometric space, a central hole is formed in the center of the homogeneous cavity, and a measuring rod of the liquid level sensor penetrates through the central hole to enable the liquid level buoy to be coaxially sleeved on the measuring rod; the homogeneous cavity is internally provided with a homogeneous annular cavity, and an annular magnet is embedded in the homogeneous annular cavity. According to the invention, the edge thickness of the central hole of the buoy is reduced, so that the overlapping area between the buoy and the measuring rod is reduced, the viscous force of the buoy is reduced when the buoy and the measuring rod move relatively in high-viscosity liquid, and the movement is more free and smooth. The buoy adopts a homogeneous cavity, so that the buoyancy can be increased. A ring magnet is arranged at the central hole and can provide a stable magnetic field for the liquid level sensor.)

1. A level float for measuring the interface of viscous liquids, comprising: the whole liquid level buoy is symmetrical about the center and comprises a homogeneous cavity (1) and an annular magnet (3); the homogeneous cavity (1) is any entity under a three-dimensional Euclidean geometric space or a three-dimensional Roba Checksky geometric space or a three-dimensional Riemann geometric space, a central hole (4) is formed in the center of the homogeneous cavity (1), and a measuring rod of the liquid level sensor penetrates through the central hole (4) to enable the liquid level buoy to be coaxially sleeved on the measuring rod; the homogeneous cavity (1) is internally provided with a homogeneous annular cavity (2), and the homogeneous annular cavity (2) is internally provided with an annular magnet (3) in an embedded manner.

2. A level float for measuring the interface of viscous liquids as defined in claim 1, wherein: along the radius to the homogeneous cavity center direction, the axial thickness at the middle part of the homogeneous cavity (1) is gradually reduced, and the axial thickness at the central hole (4) of the homogeneous cavity (1) is the minimum.

3. A level float for measuring the interface of viscous liquids as defined in claim 1, wherein: the projection shape of the central hole (4) of the homogeneous cavity (1) on the horizontal plane is a figure formed by any closed circular curve under a two-dimensional Euclidean geometric space or a two-dimensional Ropakhovis geometric space or a two-dimensional Riemann geometric space.

4. A level float for measuring the interface of viscous liquids as defined in claim 1, wherein: the material of the homogeneous cavity (1) is metal or plastic.

5. The level float for measuring a viscous liquid interface of claim 1, further comprising:

the outer surface of the homogeneous cavity (1) is coated or sprayed or electroplated with at least one protective layer of zinc, chromium, nickel, gold, palladium, rhodium, raw lacquer, urushiol resin lacquer, phenolic resin lacquer, epoxy-phenolic lacquer, epoxy resin coating, perchloroethylene lacquer, asphalt lacquer, furan resin lacquer, polyurethane lacquer, inorganic zinc-rich lacquer, polyurethane lacquer, epoxy coal tar pitch, tripolyethylene, polytetrafluoroethylene PTFE, soluble polytetrafluoroethylene PFA, polyfluortetraethylene FEP, polychlorotrifluoroethylene PCTFE, polyvinylidene fluoride PVDF, modified polypropylene GXPP, modified polyolefin GXPO, polyvinyl chloride PVC, ultrahigh polyethylene molecular weight UHMWPE and glass fiber reinforced plastic phenolic FRP.

6. The level float for measuring a viscous liquid interface of claim 1, further comprising: the liquid level buoy is in a floating state in the viscous liquid, and the central axis of the liquid level buoy is vertical when the liquid level buoy is in a static balance state.

Technical Field

The invention belongs to a liquid level buoy in the technical field of petroleum and natural gas, and particularly relates to a liquid level buoy for measuring a viscous liquid interface.

Background

Viscosity is a physical-chemical property of a substance, defined as a pair of parallel plates, area A, separated by dr, between which a liquid is filled; a pushing force F is applied to the upper plate to generate a force required for a speed change. Due to the action of viscosity, the object is subjected to frictional resistance and pressure difference resistance when moving in the fluid, and mechanical energy is lost. Since the viscosity of the liquid transmits the force layer, the liquid in each layer moves accordingly, creating a velocity gradient du/dr, referred to as shear rate, denoted by r'. F/A is called shear stress and is denoted by τ. The shear rate and the shear stress have the following relationship:

(F/A)＝η(du/dr)

the proportionality coefficient η is defined as the shear viscosity of the liquid (in addition to the extensional viscosity, the shear viscosity is frequently used at ordinary times, and generally refers to the shear viscosity without distinction, the viscosity is abbreviated as "viscosity"), so η ═ F/a)/(du/dr ═ τ/r'. Substances with higher viscosity are less prone to flow; and substances with lower viscosity flow more easily.

When the liquid level sensor using the buoy or the floating ball measures the liquid level in viscous liquid, particularly in liquid such as tar, crude oil and the like, because the buoy or the floating ball is mostly a sphere or a cylinder, the measuring rod passes through the central axis of the buoy or the floating ball, and a long and narrow cylindrical overlapping area exists between the buoy or the floating ball and the measuring rod. The overlapping area is filled with viscous liquid, the relationship between the measuring rod and the float in the overlapping area can be regarded as two horizontal plates, and according to the formula, the force F is in direct proportion to the moving speed u and the area A of each plate and in inverse proportion to the distance between the two plates. In the existing design, in order to maintain balance, the measuring rod passes through the central axis of the buoy or the floating ball, the area a of the superposed region of the measuring rod and the buoy is the largest, the clearance between the buoy and the measuring rod is as small as possible for the accurate position of the buoy or the floating ball, and for the liquid level sensor, the buoy is as close to the measuring rod as possible, namely, the distance between the two plates tends to be the smallest. The prior floating ball design causes the force F to tend to be the largest in liquids of the same viscosity. The result of practical application is that the response sensitivity of the buoy is reduced, and the liquid level change cannot be reflected in time. More commonly, the floating ball is completely stuck on the measuring rod finally due to overlarge force F, the liquid level sensor is completely out of work, and the whole body can cause a lot of losses.

Disclosure of Invention

In order to solve the problems in the background and overcome the defects in the prior art, the invention designs a liquid level buoy for measuring the interface of viscous liquid.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

the whole liquid level buoy is symmetrical about the center and comprises a homogeneous cavity and an annular magnet; the homogeneous cavity is any entity under a three-dimensional Euclidean geometric space or a three-dimensional Robacco-Techsky geometric space or a three-dimensional Riemann geometric space, a central hole is formed in the center of the homogeneous cavity, and a measuring rod of the liquid level sensor penetrates through the central hole to enable the liquid level buoy to be coaxially sleeved on the measuring rod; the homogeneous cavity is internally provided with a homogeneous annular cavity, and an annular magnet is embedded in the homogeneous annular cavity.

Along the radius to homogeneous cavity central direction, the axial thickness at homogeneous cavity middle part reduces gradually, and the axial thickness of homogeneous cavity's central hole department is minimum.

The projection shape of the central hole of the homogeneous cavity on the horizontal plane is a figure formed by any closed circular curve under a two-dimensional Euclidean geometric space or a two-dimensional Robert-Chewski geometric space or a two-dimensional Riemann geometric space.

The homogeneous cavity is made of metal or plastic.

The outer surface of the homogeneous cavity is coated or sprayed or electroplated with at least one protective layer of zinc, chromium, nickel, gold, palladium, rhodium, raw lacquer, urushiol resin lacquer, phenolic resin lacquer, epoxy-phenolic aldehyde lacquer, epoxy resin coating, perchloroethylene lacquer, asphalt lacquer, furan resin lacquer, polyurethane lacquer, inorganic zinc-rich lacquer, polyurethane lacquer, epoxy coal tar, tripolyethylene, polytetrafluoroethylene PTFE, soluble polytetrafluoroethylene PFA, polyfluorinated ethylene propylene FEP, polychlorotrifluoroethylene PCTFE, polyvinylidene fluoride PVDF, modified polypropylene GXPP, modified polyolefin GXPO, polyvinyl chloride PVC, ultrahigh molecular weight polyethylene UHMWPE and glass steel phenolic FRP.

The liquid level buoy is in a floating state in the viscous liquid, and the central axis of the liquid level buoy is vertical when the liquid level buoy is in a static balance state.

The invention has the beneficial effects that:

the thickness of the buoy is reduced on the inner edge of the central hole, so that the overlapping area of the central hole of the buoy and the measuring rod is reduced, the buoy can move smoothly along with an interface in viscous liquid, the liquid level state is reflected in real time, the viscous force F is reduced, and the buoy and the measuring rod are prevented from being adhered together by the liquid. The annular hard magnetic material is arranged in the buoy cavity, so that the density of magnetic lines of force is increased, the magnetic field distribution is uniform, the magnetic induction intensity is high, a better induction effect is obtained, the induction range can be expanded, and the distance between the central hole and the measuring rod can still be normally induced under the condition of increasing. Finally, the invention starts from the coating, and the corrosion-proof non-stick coating is coated on the buoy made of metal or plastic, so that the friction force of the liquid to which the buoy is subjected is reduced.

Through the arrangement, the relative movement area A in the viscous force formula is reduced, and the friction coefficient of the surface of the buoy is reduced. The buoy can fluctuate along with the boundary of the liquid level sensitively and accurately, and cannot be stuck on the measuring rod.

Drawings

FIG. 1 is a level float for measuring a viscous liquid interface, according to an embodiment of the present invention.

FIG. 2 is a schematic axial view of a section of a level float for measuring viscous liquid interface, in accordance with an embodiment of the present invention.

FIG. 3 is a schematic cross-sectional side view of a level float for measuring viscous liquid interface, in accordance with an embodiment of the present invention.

FIG. 4: a magnetic field simulation diagram of the cross section of the ring magnet.

In the figure: 1. homogeneous cavity, 2, homogeneous annular cavity, 3, annular magnet, 4, central hole.

Detailed Description

In order to make the objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the invention without inventive step, such as for example embodiments relating to the basic concept only with a changed use and without changing the claims, belong to the protective scope of the invention.

The whole liquid level buoy is symmetrical about the center, as shown in figures 1-3, the invention comprises a homogeneous cavity 1 and a ring magnet 3; the homogeneous cavity 1 is any entity under a three-dimensional Euclidean geometric space or a three-dimensional Robert-Chewski geometric space or a three-dimensional Riemann geometric space, a central hole 4 is formed in the center of the homogeneous cavity 1, the axial thickness of the middle of the homogeneous cavity 1 is gradually reduced along the radius direction to the center of the homogeneous cavity, and the axial thickness of the central hole 4 of the homogeneous cavity 1 is the minimum. The projection shape of the central hole 4 of the homogeneous cavity 1 on the horizontal plane is a figure formed by any closed circular curve under a two-dimensional Euclidean geometric space or a two-dimensional Robert-Chewski geometric space or a two-dimensional Riemann geometric space. The homogeneous cavity 1 is internally provided with a homogeneous annular cavity 2, and the homogeneous annular cavity 2 is internally provided with an annular magnet 3 in an embedded manner.

The material of the homogeneous cavity 1 is metal or plastic. The outer surface of the homogeneous cavity 1 is coated or sprayed or electroplated with zinc, chromium, nickel, gold, palladium, rhodium, raw lacquer, urushiol lacquer, phenolic resin lacquer, epoxy-phenolic lacquer,Epoxy resin paint, perchloroethylene paint, asphalt paint, furan resin paint, polyurethane paint, inorganic zinc-rich paint, polyurethane paint, epoxy coal pitch, tripolyethylene, polytetrafluoroethylene PTFE, soluble polytetrafluoroethylene PFA, polyfluoroethylene propylene FEP, polychlorotrifluoroethylene PCTFE, polyvinylidene fluoride PVDF, modified polypropylene GXPP, modified polyolefin GXPO, polyvinyl chloride PVC, ultrahigh molecular weight polyethylene UHMWPE and glass fiber reinforced plastic phenolic FRP. In the specific implementation, the surface is coated or sprayed with three protective layers of polytetrafluoroethylene PTFE, fluorinated ethylene propylene FEP and glass fiber reinforced plastic phenolic FRP. In certain acidic, alkaline and corrosive liquids, the buoy is not resistant to corrosion of the liquid by the material of the buoy alone, and the surface of the buoy must be coated with traditional coatings such as raw lacquer, epoxy resin, phenolic resin and the like, so that the buoy can be well protected. With the vigorous development of fluorine chemical industry, new anticorrosive coatings such as polytetrafluoroethylene PTFE, soluble polytetrafluoroethylene PFA, fluorinated ethylene propylene FEP, polychlorotrifluoroethylene PCTFE and polyvinylidene fluoride PVDF are used, which not only have superior corrosion and oxidation resistance, but also have low friction coefficient and can be used as lubricant per se, and when a buoy coated with such a coating moves in a viscous liquid, the friction with the viscous liquid is smaller, and the viscosity F becomes smaller. Similarly, the diameter of the measuring rod of the sensor is reduced, and the protective layer is coated on the measuring rod, so that the effects of corrosion resistance, lubrication and reduction of viscous force F can be achieved. Average density of float is 0.9g/cm³In two liquids to be tested (water: 1.0 g/cm)³Crude oil: 0.81g/cm³) Density to ensure that the interface position can be correctly indicated when the buoy is statically balanced.

After the measuring rod of the liquid level sensor penetrates through the central hole 4, the liquid level buoy is coaxially sleeved on the measuring rod, so that the liquid level buoy is ensured to linearly move along the measuring rod direction of the sensor, and the position of the liquid level is tracked. . The liquid level buoy is in a floating state in the viscous liquid, and the central axis of the liquid level buoy is vertical when the liquid level buoy is in a static balance state. According to the Archimedes principle of buoyancy, a body immersed in a stationary fluid is subjected to a buoyancy force equal to the weight of the fluid displaced by the body, directed vertically upwards and through the centroid of the displaced fluid. In this state, only if the central hole is kept in a straight state, unnecessary direct friction between the buoy and the measuring rod can not be generated, and the buoy is guaranteed to normally fluctuate along with the liquid level.

Therefore, the invention effectively reduces the viscous force of the liquid level buoy moving in the high-viscosity liquid, prevents the liquid from adhering the buoy and the measuring rod together, enables the buoy to more smoothly fluctuate along with the liquid level in the viscous liquid and reflects the liquid level state in real time. In the embodiment of the present invention, an annular hard magnetic material is further disposed in the float cavity, so that the magnetic line of force is increased in density, the magnetic induction intensity is increased, and the magnetic field is symmetrically distributed, as shown in fig. 4, fig. 4 is an MATLAB magnetic field simulation of the used annular magnet, an arrow in the figure represents the magnetic field direction, and the right side is labeled as the magnetic induction intensity, unit: t (Tesla). A mathematical model is established by utilizing an ampere molecular current hypothesis and a loop integral theorem to obtain a cross section magnetic induction vector field distribution diagram of the used ring magnet, the magnetic induction intensity of the common hard magnetic material can reach about 0.1T, a better induction effect is obtained, and the precision of liquid level measurement is improved.