CN1122824C - Self-calibrating capacitor-type liquid level gauge - Google Patents

Abstract

The present invention relates to a self-calibrating capacitance level meter which comprises a measurement sensor and a calibrating sensor which is arranged at the lower part of the measurement sensor, wherein the measurement sensor is composed of internal tubes and external tubes sheathed on the internal tubes; each internal tube is formed by the butt joint of a plurality of short internal tubes, and each external tube is formed by the butt joint of short external tubes. Both ends of each of the internal tubes are respectively provided with the bottom end joints of the internal tubes and the top end joints of the internal tubes. Both ends of each of the external tubes are respectively provided with the bottom end joints of the external tubes and the top end joints of the external tubes. The calibrating sensor comprises the middle tubes of the internal tubes and the external tubes which are sheathed together and top covers and bottom covers which are arranged at both ends of each of the middle tubes of the internal tubes. The present invention can automatically compensate the influences of temperature pressure, environment, etc., and has the advantages of high liquid level precision and high stability.

Description

Self-calibrating capacitor-type liquid level gauge

(1) technical field

The invention belongs to a kind of measurement mechanism of liquid level

(2) background technology

At present artificial method is still adopted in the measurement of liquid level in domestic many wet tanks, and this is not only very inconvenient, has very big danger, and measures untimelyly, can not realize that remote clustered measures and control the requirement of incompatibility modern management automatically.For the storage tank of High Temperature High Pressure, the artificial especially institute of poisonous and harmful medium is irrealizable.

The automatic side amount liquid level gauge of supplying on the market is of a great variety now, and the product of multiple principles such as float-ball type, pressure transducer formula, laser type, ultrasonic type is arranged.The mechanical part that has frequent activities that has, what have is stable very poor, changed by physical parameters such as measured medium temperature, density and the influence of environmental change, makes accuracy of measurement and long-time stability very undesirable.

(3) summary of the invention

The technical problem to be solved in the present invention provides and a kind ofly can compensate the self-calibrating capacitor-type liquid level gauge of measurement accuracy height, good stability automatically to the influence that temperature, pressure, Media density, specific inductive capacity, environmental baseline, component aging, power source change etc. are produced.Be applicable to the level gauging of non-electrically conductive liquid medium.

The technical scheme that adopts is:

Self-calibrating capacitor-type liquid level gauge, by the coaxial-type capacitive transducer that calibrating sensors and survey sensor are formed, interior pipe, outer tube are respectively as two electrodes of electric capacity.Calibrating sensors is arranged on a side of survey sensor bottom, and is fixed together.

Survey sensor comprises outer tube, interior pipe, outer tube bottom joint, outer tube top joint, interior pipe bottom joint, interior pipe top joint.Outer tube is made of the short outer tube butt joint of more piece, is made of the short interior pipe butt joint of more piece pipe.In the upper end of pipe bottom joint insert in the infratubal port, and closely cooperate and be fixed together.In the lower end of pipe top joint insert in the pipe upper port, closely cooperate and be fixed together.The upper end of outer tube bottom joint is sleeved on the outer tube lower end, closely cooperates and is fixed together.The lower end of outer tube top joint is sleeved on the upper end of outer tube, closely cooperates and is fixed together, and the coaxial heart of interior pipe of pipe bottom joint and top joint is installed in the outer tube in being provided with.Outer wall of inner tube is identical with distance between the outer tube wall.After loading onto dead ring respectively in interior pipe lower end and upper end, tight with the back of the body cap back of the body respectively.

Calibrating sensors, the parallel multipole capacitance type sensor of forming by a plurality of stainless-steel tube coaxial packages.Cover in the pipe in the upper and lower end of pipe of being included is equiped with respectively, cover is fixedlyed connected with interior pipe by screw in the interior pipe.Upper and lower end at coaxial package a plurality of stainless-steel tubes together is fixed with top cover and bottom respectively.

For above-mentioned survey sensor, can a sheathed clamp at the joint of the short outer tubes of per two joints, clamp two ends joint links together with the clamp screw retention, and the joint of per two short outer tubes also can be by flange connection or thread connection.

Interior pipe connector sleeves of interior Guan Like installing of the joint of pipe in per two weak points, interior pipe connector sleeves and interior pipe are by screw retention together.

For make whole in the distance of inwall of outer wall and whole outer tube of pipe keep equidistant constant, in each, install a stop means on the pipe connector sleeves.This stop means can be a plurality of stop screws.In the corresponding with it bolt hole in the front end of a plurality of stop screws screws in respectively on the pipe connector sleeves, the rear end of a plurality of stop screws is replaced respectively on the inwall of outer tube.This stop means can also adopt spacing ring, and on the pipe connector sleeves, the outer face of spacing ring contacted with outer tube wall and closely cooperates in spacing ring was sleeved on.On spacing ring, be provided with a plurality of holes, or on the outer face of spacing ring or inner face, a plurality of grooves arranged.

In order to hang conveniently, on the joint of outer tube top, be equiped with fixedly hanger, fixedly hanger is connected with outer tube top joint by bolt.

Above-mentioned calibrating sensors can be made up of a plurality of coaxial packages stainless-steel tube together.Put in interior pipe and can install stop means, this stop means can be a plurality of stop screws.In the corresponding with it bolt hole that puts in the pipe in the front end of a plurality of stop screws screws in respectively, the rear end of a plurality of stop screws is replaced respectively on middle inside pipe wall.Stop means also can be spacing ring.Put in the pipe in spacing ring is sleeved on, the outer face of spacing ring contacts with the inwall of middle pipe, and closely cooperates.A plurality of holes are arranged on spacing ring, or on the outer face of spacing ring or inner face, a plurality of grooves are arranged.

The present invention cooperates with signal converter and display, can accurately measure the liquid level of the liquid of institute's splendid attire in the container, and its principle of work is as follows:

Calibrating sensors is dipped in the real work in the measured medium entirely, is in the full scale duty all the time.Its relative geometrical length amount (H _O) be a constant.The principle of work of liquid level gauge is as follows:

If survey sensor, calibrating sensors Displaying Meter under idle condition is respectively N to the numerical value of its measurement _COAnd N _JO, measured value is respectively N again in the real work _C1And N _J1, then actual measurement highly is: $h=\frac{N_{C1}-N_{\mathrm{CO}}}{N_{J2}-N_{\mathrm{JO}}}\×H_O+\mathrm{\ΔH}---\left(1\right)$

Δ H is the poor of liquid level gauge zero point and storage tank metering basic point in the formula.

Automatic compensation principle

If because a certain amount of influence changes in the liquid level gauge work, caused measuring error, this moment, Displaying Meter had an increment Delta N respectively to the measured value of survey sensor and calibrating sensors under the above-mentioned sustained height liquid level _C1With Δ N _J1Simultaneously liquid level gauge two zero points also respective change Δ N _COWith Δ N _JOBecause two sensors are in same working environment, and carry out the A/D conversion by a signal converter, therefore the rate of change of above-mentioned variable quantity should equate that establishing rate of change is K, then:

ΔN _C1＝KN _C1 ΔN _CO＝KN _CO

ΔN _J1＝KN _J1 ΔN _JO＝KN _JO

Substitution (1) Shi Kede: $h=\frac{(N_{C1}+{\mathrm{\ΔN}}_{C1})-(N_{\mathrm{CO}}+{\mathrm{\ΔN}}_{\mathrm{CO}})}{(N_{J1}+{\mathrm{\ΔN}}_{J1})-(N_{\mathrm{JO}}+{\mathrm{\ΔN}}_{\mathrm{JO}})}{\×H}_O+\mathrm{\ΔH}$ $=\frac{(N_{C1}-N_{\mathrm{CO}})(1+K)}{(N_{J1}-N_{\mathrm{JO}})(1+K)}\×H_O+\mathrm{\ΔH}$ $=\frac{N_{C1}-N_{\mathrm{CO}}}{N_{J1}-N_{\mathrm{CO}}}\×H_O+\mathrm{\ΔH}=\left(1\right)$ Formula

Following formula as can be seen, the error that causes of influential quantitative changeization to sensor zero point drift and measurement result, all obtained compensating accurately.

The present invention can carry out comprehensively compensation automatically to the influence of the influential quantitative changeizations of institute such as temperature, pressure, Media density, specific inductive capacity, environmental baseline, component aging, power source change, has the accuracy of measurement height, long-time stability are good, advantages such as applied range easy to install.

(4) description of drawings

Fig. 1 is the surface structure synoptic diagram of a kind of embodiment of the present invention, and Fig. 2 is the survey sensor structural representation, and Fig. 3 is the calibrating sensors structural representation.

(5) embodiment

Self-calibrating capacitor-type liquid level gauge, the coaxial electrical capacity sensor of forming by calibrating sensors and survey sensor.Survey sensor comprises outer tube, interior pipe, outer tube bottom joint 1, outer tube top joint 2, interior pipe bottom joint 3, interior pipe top joint 4.

Outer tube is made up of short outer tube 5 butt joints of more piece, is arranged with clamp 6 at the joint of per two short outer tubes 5, and it is fixedly connected that the two ends joint of clamp 6 passes through clamp screw 7, and joint is tightened.The upper end of outer tube bottom joint 1 is sleeved on the lower end of outer tube, and is connected with the outer tube solid welding.The lower end of outer tube top joint 2 is sleeved on the upper end of outer tube, and is connected with the outer tube solid welding.

Interior pipe is connected and composed by the short interior pipe 8 of more piece, manages 8 joint in per two weak points, and interior pipe connector sleeves 9 of installing in the pipes in two weak points, interior pipe connector sleeves 9 pass through to manage in screw 10 and two weak points 8 fixedlys connected.Have the lower end of 11, four stop screws 12 of four screw holes to insert respectively in four screw holes 11 in each on the pipe connector sleeves, with thread connection, the other end of four stop screws 12 is low respectively to withstand on the inwall of outer tube.Insert in the interior pipe upper end of interior pipe bottom joint 3, and fixedly connected with interior pipe, and insert in the upper port of interior pipe the lower end of interior pipe top joint 4, and be connected with interior pipe solid welding.After being set with dead ring 13 on interior pipe bottom joint 3 and the interior pipe top joint 4, tight with back of the body cap 14 back ofs the body respectively, on outer tube top joint 2, be equiped with hanger 15, hanger 15 is connected with outer tube top joint 2 by bolt 16.

Calibrating sensors, by outer tube 17, middle pipe 18, interior pipe 19, in two in the pipe cover 20, top cover 21 and bottom 22 form.Interior pipe 19, middle pipe 18, outer tube 17 concentrics are sleeved on together.Cover 20 in the pipe in be equipped with respectively the top and bottom of interior pipe 19 overlaps 20 in the interior pipe and fixedlys connected with interior pipe 19 by screw.In each in the pipe on the cover 23 and with interior pipe in cover 20 four screw holes 11 are arranged on the pipes in corresponding, in four screw holes 11, screw in stop screw 24 respectively, the upper end of stop screw 24 is replaced respectively on the inwall of middle pipe 18.Top cover 21, bottom 22 are fixedly arranged on the two ends of the interior pipe 19 that is sleeved on together, middle pipe 18, outer tube 17 respectively.

Calibrating sensors 25 is set up in parallel in the bottom of survey sensor 23, and is fixed together by clamp 6.

Above-mentioned stop screw 12 and 24 can replace with spacing ring, and spacing ring is sleeved on interior pipe connector sleeves 9 or the interior pipe 19.Can offer a plurality of holes on the spacing ring, or groove, so that liquid passes through.

Serve as reasons pottery, rubber or plastics of cover 23 are made in above-mentioned stop screw 12,24 of the present invention and dead ring, the interior pipe, and other part is made by stainless steel or titanium steel.

Above-mentioned clamp 6 of the present invention can also be with screw thread or flange connection.

Claims (3)

1, self-calibrating capacitor-type liquid level gauge comprises calibrating sensors (25), survey sensor (23), and calibrating sensors (25) is arranged on the bottom of survey sensor (23), and is fixed together, and it is characterized in that:

A, survey sensor (23) comprise outer tube, interior pipe, outer tube bottom joint (1), outer tube top joint (2), interior pipe bottom joint (3), interior pipe top joint (4), hanger (15); Outer tube is made up of the short outer tube of more piece (5) butt joint; Interior pipe is arranged in the outer tube, and concentric; The upper end of outer tube bottom joint (1) is sleeved on the lower end of outer tube, and is connected with the outer tube solid welding; The lower end of outer tube top joint (2) is sleeved on the upper end of outer tube, and is connected with the outer tube solid welding; Interior pipe is formed by managing (8) butt joint in the more piece weak point, and insert in the lower port of interior pipe the upper end of interior pipe bottom joint (3), and fixedly connected with interior pipe, and insert in the lower port of interior pipe the lower end of interior pipe top joint (4), and fixedly connected with interior pipe; On interior pipe bottom joint (3) and interior pipe top joint (4), be respectively installed with dead ring (13), and tight with back of the body cap (14) back of the body respectively, on outer tube top joint (2), be installed with hanger (15);

B, calibrating sensors (25) comprise in the outer tube (17), middle pipe (18), interior pipe (19), two cover (20), top cover (21) and bottom (22) in the pipe; Interior pipe (19), middle pipe (18), outer tube (17) are sleeved on together, and concentric, and cover (20) in the pipe in be equipped with respectively the top and bottom of interior pipe (19) overlaps (20) and fixedlys connected with interior pipe (19) by screw in the interior pipe; Top cover (21) and bottom (22) are fixedly arranged on the two ends of the interior pipe (19) that is sleeved on together, middle pipe (18), outer tube (17) respectively.

2, self-calibrating capacitor-type liquid level gauge according to claim 1, it is characterized in that being arranged with clamp (6) at the joint of described per two short outer tubes (5), the two ends of clamp (6) link together by the clamp screw, the joint of pipe (8) manages that device has interior pipe connector sleeves (9) in (8) in short in described per two weak points, interior pipe connector sleeves (9) is fixedlyed connected with pipe (8) in two weak points by screw (10), interior pipe connector sleeves (9) is provided with stop means, stop means is a plurality of stop screws (12), the lower end of a plurality of stop screws screws in respectively in the screw hole (11) of the correspondence with it on the interior pipe connector sleeves (9), and its upper end is replaced respectively on outer tube wall; Pipe (19) is provided with stop means in described, this stop means is a plurality of stop screws (24), the lower end of a plurality of stop screws (24) screws in respectively in the screw hole that overlaps in interior pipe (19) and the interior pipe on (20), and its upper end is replaced respectively on the inwall of middle pipe (18).

3, self-calibrating capacitor-type liquid level gauge according to claim 1 is characterized in that the described stop means that upward is provided with at interior pipe (19) also can be spacing ring, and spacing ring is sleeved on the interior pipe (19), and a plurality of holes or a plurality of groove can be arranged on the spacing ring.

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