CN102590643A - Gas-solid phase pipe flow static measuring appliance and measuring method - Google Patents

Abstract

The invention discloses to a gas-solid phase pipe flow static measuring appliance and a gas-solid phase pipe flow static measuring method, and relates to a pipe flow static measuring device. The gas-solid pipe flow static measuring device is provided with an internal shielding metal layer, a first insulating layer, a metal layer, a second insulating layer and an external fielding metal layer in sequence from inside to outside. The internal shielding metal layer is provided with an electrode, and is grounded, the metal layer is provided with a measuring electrode, the measuring electrode is externally connected with a static measuring instrument, and the external shielding metal layer is grounded. A pipeline to be measured is inserted into the internal shielding metal layer, and the internal shielding metal layer is tightly attached to the outer wall of the pipeline to be measured. A computer and the static measuring instrument are started, a program window for controlling the static measuring instrument in the computer is started, and a data recording program of the static measuring instrument is started. When the gas-solid phase pipe flow static measuring appliance is started, particles move in the pipeline to be measured by pneumatic transmission, and static generated when the particles impact the wall surface of the pipeline is measured. After the measurement, the gas-solid phase pipe flow static measuring appliance is turned off, the pneumatic transmission is stopped, and a measurement controlling window of the computer is closed, and the static measuring instrument is turned off to accomplish the measuring process.

Description

Gas-solid two phase tube flow electrostatic measurement device and measuring method

Technical field

The present invention relates to a kind of pipe stream electrostatic measurement device, especially relate to a kind of gas-solid two phase tube flow electrostatic measurement device and measuring method.

Background technology

Electrostatic phenomenon extensively exists at nature and daily life.In actual industrial production, electrostatic phenomenon also exists in a large number, the directly normal work of influence, even bring danger and accident.For example in gas-solid two phase tube flow is carried, advantage such as that non-metal insulating material has is corrosion-resistant, life-span length, cleaning and be widely used in fields such as food, chemical industry, medicine, the energy.Because particle and pipe wall material is different, will produce static after particle and the tube wall collision.Because pipeline material is nonmetal, so in particle and the continuous collision of tube wall, electrostatic charge will possibly cause a large amount of particles to be adsorbed on tube wall and cause mobile variation in the accumulation of tube wall wall on the one hand; On the other hand, a large amount of electric charges possibly cause the pipeline shelf depreciation to produce electric spark and light damp/inflammability particle (the textile fibres)/gas-solid mixture in the hazardous area, blast, major accident such as fire.Therefore, research and the protection to static is the important topic that industry member faces always.

Gas-solid two phase tube flow relates to the working environment of more complicated in actual production, accurate measurement partial electrostatic is caused very big difficulty.Be because interior charged particle of pipeline and broken granule (or dust) make the interior current system of pipeline be full of static on the one hand; On the other hand, can accumulate electrostatic charge on the nonmetal pipeline tube wall.Because the singularity of electrostatic induction and the faint property (10e-7) of signal, above-mentioned factor causes very big difficulty to accurate measuring channel partial electrostatic.At present, the measuring method of static has a lot, but has often ignored around external environment and the tested position factor to the influence of electrostatic measurement precision.Because tested electrostatic signal is very low, measurement result is easy to disturbed.Therefore, a kind of simple and electrostatic methods high-acruracy survey gas-solid two phase tube flow of invention seems and is even more important.

Chinese patent CN 201662597U discloses a kind of fluid line electrostatic measurement device; Comprise coulombmeter, electrostatic field appearance, medium transport pipeline simulation system; Medium transport pipeline simulation system comprises five stop valves, pneumatic diaphragm pump, two medium jars, tested pipeline and media; Two stop valve one ends are connected in parallel on pneumatic diaphragm pump one end, and other two stop valves are connected in parallel on the other end of pneumatic diaphragm pump; The other end of two stop valves is connected in parallel on an end of the first medium jar, and the other end of two stop valves is connected in parallel on an end of tested pipeline in addition; The other end of tested pipeline links to each other with an end of the second medium jar, and its other end links to each other with the other end of the first medium jar, and the 5th stop valve is connected between two medium jars, and coulombmeter, electrostatic field appearance are that induced signal is connected with tested pipeline.

Chinese patent CN201796091U discloses a kind of Dual-Phrase Distribution of Gas olid electrostatic signal that is used for and collects the electrostatic inductor of measuring.Comprise probe, insulating element, shell, connecting rod, terminal box, external cable and electric wire; Probe, connecting rod are connected successively with external cable and are arranged in the cavity of shell and terminal box composition, and an end of probe stretches out shell; Probe, connecting rod, external cable insulate through insulating element and shell, terminal box; Terminal box is through electric wire ground connection.

Wang Fang etc. (Wang Fang, Wang Jingdai, sun are flourish forever. and dynamically the powder electrostatic Research on Measuring Technology is made progress. chemical process automation and instrument, 2008,35:1-6) reported relevant dynamically powder electrostatic Research on Measuring Technology progress.

Summary of the invention

The purpose of this invention is to provide a kind of non-destructive gas-solid two phase tube flow electrostatic measurement device and measuring method.

Said gas-solid two phase tube flow electrostatic measurement device is provided with inner screening metal level, the 1st insulation course, metal level, the 2nd insulation course and external shield metal level from the inside to the outside successively; Said inner screening metal level is provided with electrode, and said electrode is drawn and ground connection by lead; Said metal level is provided with potential electrode, the external electrostatic measurement appearance of said potential electrode; Said external shield metal level is connected with ground through lead; During measurement, said inner screening metal level is close to the outer wall of tested pipeline.

The bore of said inner screening metal level can be 0.005～4m.

Tested pipeline can be all kinds of metallic conduits and isolated pipe, and the length of said tested pipeline can be 0.05～1m.

Said gas-solid two phase tube flow electrostatic measurement method adopts said gas-solid two phase tube flow electrostatic measurement device, may further comprise the steps:

1) tested pipeline is inserted in the inner screening metal level of said gas-solid two phase tube flow electrostatic measurement device, said inner screening metal level is close to the outer wall of tested pipeline;

2) open computer and electrostatic measurement appearance, get into the program window of control electrostatic measurement appearance in the computer, start the data recording program of electrostatic measurement appearance;

3) open gas-solid two phase tube flow electrostatic measurement device, particle moves in tested pipeline under strength is carried, through the static of gas-solid two phase tube flow electrostatic measurement measurement device impact of particles pipeline wall generation;

4) electrostatic measurement finishes, and closes gas-solid two phase tube flow electrostatic measurement device, stops strength and carries, and closes the control window that computer is measured, and closes the electrostatic measurement appearance at last, accomplishes measuring process.

Compare with existing gas-solid two phase tube flow electrostatic measurement device and measuring method, the present invention fully reduces the influence of external environment to measuring, and ensures the accuracy of measuring; Secondly, metering system is simplified, and all indexs of static (induction current, induced voltage, induction electric weight) are measured through same instrument, reduces different measuring mode and instrument cubicle and disturbs errors caused each other.

Description of drawings

Fig. 1 is that the structure of gas-solid two phase tube flow electrostatic measurement device is formed synoptic diagram.

Fig. 2 is an electrostatic measurement induction current in the pipeline.In Fig. 2, horizontal ordinate is time T (s), and ordinate is induction current I (A).

Fig. 3 is an electrostatic measurement average current in the pipeline.In Fig. 3, horizontal ordinate is time T (s), and ordinate is average current Im (A).

Embodiment

Referring to Fig. 1, said gas-solid two phase tube flow electrostatic measurement device embodiment is provided with inner screening metal level the 2, the 1st insulation course 3, metal level the 4, the 2nd insulation course 5 and external shield metal level 6 from the inside to the outside successively; Said inner screening metal level 2 is provided with electrode, and said electrode is drawn and ground connection by lead; Said metal level 4 is provided with potential electrode, the external electrostatic measurement appearance of said potential electrode; Said external shield metal level 6 is connected with ground through lead; During measurement, said inner screening metal level 2 is close to the outer wall of tested pipeline 1.

The bore of said inner screening metal level 2 can be 0.005～4m.

Tested pipeline can be all kinds of metallic conduits and isolated pipe, and the length of said tested pipeline can be 0.05～1m.

In said gas-solid two phase tube flow electrostatic measurement device, inner screening metal level 2, metal level 4 and external shield metal level 6 are metal level; The 1st insulation course 3 and the 2nd insulation course 5 and tested pipeline 1 are insulation course.

As adopting measuring accuracy, higher (electric current, resistance and electric capacity all reach 10e ^-18) instrument, can not need amplifier just can obtain accurate signal like Japanese Advantest R8252.Surveying instrument links to each other with computer through special data cable, and computer has the corresponding data acquisition software systems, the operation of final computer ability apparatus for automatic control.

During use, at first need use particle and system to carry out discharge process (more than the 24h) to experiment; Secondly, before measurement of electrostatic, need to measure definite to temperature, humidity, pipe surface roughness, particle and the pipeline material etc. of measurement environment; In addition, for fear of the influence of humidity, in experimental system, adopt drying agent to guarantee that the aridity of polyphasic flow in the pipeline keeps constant to static.

During measurement, at first, tested pipeline is inserted in the inner screening metal level of said gas-solid two phase tube flow electrostatic measurement device, said inner screening metal level is close to the outer wall of tested pipeline; Secondly, open computer and electrostatic measurement appearance, get into the program window of control electrostatic measurement appearance in the computer, start the data recording program of electrostatic measurement appearance; The 3rd, open gas-solid two phase tube flow electrostatic measurement device, particle moves in tested pipeline under strength is carried, through the static of gas-solid two phase tube flow electrostatic measurement measurement device impact of particles pipeline wall generation; At last, electrostatic measurement finishes, and closes gas-solid two phase tube flow electrostatic measurement device, stops strength and carries, and closes the control window that computer is measured, and closes the electrostatic measurement appearance at last, accomplishes measuring process.

Said gas-solid two phase tube flow electrostatic measurement device can obtain the interior charged particle of closed conduct and duct wall attaches the induced signal that electric charge is produced.The situation (referring to Fig. 2) of positive negative variation appears in the direct measuring-signal of instrumentation in the measurement, in a period of time, carries out integration (seeing formula (1)) to measuring the gained signal, can obtain unipolar signal result (referring to Fig. 3).

$\stackrel{\‾}{I}=\frac{1}{T}{\∫}_0^{T}I\·\mathrm{dt}---\left(1\right)$

In the formula (1), I is the induction current that instrument measures, and T is integral time.

Claims (3)

1. gas-solid two phase tube flow electrostatic measurement device is characterized in that being provided with successively from the inside to the outside inner screening metal level, the 1st insulation course, metal level, the 2nd insulation course and external shield metal level; Said inner screening metal level is provided with electrode, and said electrode is drawn and ground connection by lead; Said metal level is provided with potential electrode, the external electrostatic measurement appearance of said potential electrode; Said external shield metal level is connected with ground through lead; During measurement, said inner screening metal level is close to the outer wall of tested pipeline.

2. gas-solid two phase tube flow electrostatic measurement device as claimed in claim 1, the bore that it is characterized in that said inner screening metal level is 0.005～4m.

3. gas-solid two phase tube flow electrostatic measurement method is characterized in that adopting gas-solid two phase tube flow electrostatic measurement device according to claim 1 or claim 2, and said measuring method may further comprise the steps:

1) tested pipeline is inserted in the inner screening metal level of said gas-solid two phase tube flow electrostatic measurement device, said inner screening metal level is close to the outer wall of tested pipeline;

2) open computer and electrostatic measurement appearance, get into the program window of control electrostatic measurement appearance in the computer, start the data recording program of electrostatic measurement appearance;

3) open gas-solid two phase tube flow electrostatic measurement device, particle moves in tested pipeline under strength is carried, through the static of gas-solid two phase tube flow electrostatic measurement measurement device impact of particles pipeline wall generation;

4) electrostatic measurement finishes, and closes gas-solid two phase tube flow electrostatic measurement device, stops strength and carries, and closes the control window that computer is measured, and closes the electrostatic measurement appearance at last, accomplishes measuring process.

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