CN103512829B - A kind of method by muddy water density measure sediment concentration - Google Patents

Abstract

The present invention relates to a kind of method by muddy water density measure sediment concentration, it comprises the following steps: the 1) preparatory stage: 1. weigh the Sediment quality M as husky sample _s, and put into a container, measure clear water volume V _w, pour in described container, stir into muddy water; 2. the muddy water volume V that 1. obtains of measuring process, calculates silt volume V in muddy water _s=V-V _w; 3. silt density p is calculated _s=M _s/ V _s; 2) test phase: 1. weigh muddy water mass M to be measured, measures the volume V of muddy water to be measured; 2. muddy water density p=M/V and clear water density p is calculated _w=M _wv _w; 3. calculate and obtain silt volumetric concentration C _v=(ρ-ρ _w) (ρ _s-ρ _w).The present invention can be applied in the sediment concentrations such as muddy water river, power station, pump works and measure, pressure flow moves, sediment concentration in Open Channels in simulation test device is measured and the demarcation of various concentration measuring instrument, during the concentration of solid particles comprising all solid-liquid two-phase flows of solid particle is measured.

Description

A kind of method by muddy water density measure sediment concentration

Technical field

The present invention relates to a kind of sediment concentration measuring method, particularly about a kind of method by muddy water density measure sediment concentration.

Background technology

We daily life, in industrial and agricultural production and scientific research, often need understand or measure two or more different medium and mix rear ratio shared separately, typical concentrations is stated in a liquid.Such as, the muddy water containing sand grain, often needs to measure the concentration of these sand grains in water.Concentration has two kinds of main expression waies, i.e. volumetric concentration and mass concentration.With regard to sediment concentration, volumetric concentration C _vthe ratio of volume shared by silt and muddy water cumulative volume in muddy water, and mass concentration C _mit is then the ratio of Sediment quality and muddy water gross mass in muddy water.In engineering practice, engineering technical personnel's conventional unit volume muddy water of China containing sandy amount C' _m(C' _m=M _s/ V, wherein V is muddy water volume, M _ssediment quality in muddy water) state the concentration of sand grain in muddy water, be referred to as silt content, its conventional unit is kg/m ³.In sediment concentration is measured, general method is weight method: get the muddy water containing sand grain that volume is V, after adopting the methods such as filtration to filter most moisture content, then carry out drying, weighing, obtain sand grain mass M _s, namely can calculate silt content C' _m(C' _m=M _s/ V), in above-mentioned metering system, only measure silt content C' _m, do not measure silt density p _s, only general employing quartz sand density 2650kg/m ³carry out approximate treatment muddy water volumetric concentration C _v(C _v=C' _m/ ρ _s).

It is not enough to there are following three aspects in above-mentioned weight method: if the mineral types of the solid particles such as 1 silt is different, the ratio of various mineral matter is different, its density can be different, generally replace the density containing different minerals matter silt certainly will bring very large error because it is uncertain by quartz sand density; It is very careful, careful that the filtration of silt needs, careless slightly all may because of the bringing into of silt, take out of and increase test error.2, operating process is loaded down with trivial details, and labour intensity is large.3, due to silt filtration, dry very loaded down with trivial details, consuming time, often need a tediously long measuring process, namely measurement result can not be surveyed and get final product, and can only first sample, then C' is determined in the measurement that chooses the right moment _m, make test after all cannot obtain concentration or silt content value for a long time, wrong in test process also cannot Timeliness coverage.

Along with the progress of measuring technology, sediment concentration is measured and is adopted real time on-line monitoring to become development trend.For now, the multiple measurement of concetration modes such as ultrasonic attenuation method, photoelectric method (infra-red method) and gamma-rays method are had.In these metering systems, its measurement result mostly is volumetric concentration or mass concentration, be converted into the silt content C' that China is conventional _m, also need to use silt density p _scarry out converting (C' _m=C _vρ _s), be necessary accurately to measure ρ _s.Although the mineral density of composition sand grain be determine, can survey, have multiple different minerals matter particle with determine but unknown concrete ratio combination becomes silt time, its density is uncertain, therefore can not calculate acquisition, can only measure.But have gap between sand grain, this gap, therefore cannot Measurement accuracy silt density in an atmosphere also because particle diameter, grating are different different and different with compactness.

Summary of the invention

For the problems referred to above, the object of this invention is to provide a kind of simple to operate, measuring accuracy is high and namely test result is surveyed and the method by muddy water density measure sediment concentration that obtains.

For achieving the above object, the present invention takes following technical scheme: a kind of method by muddy water density measure sediment concentration, and it comprises the following steps: the 1) preparatory stage: obtain silt density p _s: 1. weigh the Sediment quality M as husky sample _s, and put into a container, measure clear water volume V _w, pour in described container, stir into muddy water; 2. the muddy water volume V that 1. obtains of measuring process, calculates silt volume V in muddy water _s=V-V _w; 3. silt density p is calculated _s=M _s/ V _s; 2) test phase: the various mineral types of survey calculation and mineral matter ratio and step 1) in silt volumetric concentration C in the step muddy water that 1. described husky sample is basically identical _v: 1. weigh muddy water mass M to be measured, measure the volume V of muddy water to be measured; 2. muddy water density p=M/V and clear water density is calculated 3. calculate and obtain silt volumetric concentration

Can by silt volumetric concentration C _vbe converted into silt content C' conventional in industry _m:

C' _M＝ρ _S·C _V。

Described step 2) in silt volumetric concentration derivation as follows:

Silt is shared volume V in muddy water _sfor:

V _S＝V-V _W(1)

And silt density p in muddy water _sfor:

ρ _s＝M _s/V _s(2)

In muddy water, between Sediment quality and clear water quality, there is following relation:

ρ·V＝ρ _S·V _S+ρ _w·V _w(3)

And silt volume can be expressed as:

V _S＝C _V·V(4)

Clear water volume can be expressed as:

V _W＝V-V _S(5)

Formula (4) and formula (5) are substituted into formula (3) respectively:

ρ·V＝ρ _S·C _V·V+ρ _W(V-C _V·V)(6)

Obtain after simplify processes is carried out to formula (6):

$C_V=\frac{\mathrm{\ρ}-{\mathrm{\ρ}}_W}{{\mathrm{\ρ}}_S-{\mathrm{\ρ}}_W}.---\left(7\right)$

Obtain Sediment quality M _sduring with muddy water mass M to be measured, standard weighing-appliance is adopted to weigh acquisition.

Obtain clear water volume V _wduring with muddy water volume V, the orthobaric volume cylinder bucket metering of metered volume is adopted to obtain.

The present invention is owing to taking following technical scheme, it has the following advantages: 1, the present invention converts the method survey calculation determination silt density of standard volume clear water owing to directly weighing with required silt, and this density does not substantially change with size grading for the solid particle of identical mineral matter, also very little by Water Temperature, can think ρ under water temperature change ratio that is little, the substantially identical or different mineral matter of mineral matter keeps basically identical condition _sremain unchanged, therefore do not need each concentration to measure ρ _s, thus each concentration can be avoided to filter and toast silt, both reduced labour intensity, significantly shortened the test duration again, test result can also be made namely to survey and get final product.2, the present invention is owing to accurately measuring silt density p _s, no matter be by C _vconversion C' _m, or by C' _mconversion C _v, all use quartz sand density 2650kg/m than in the past ³generally value is more accurate for this.

Embodiment

Below in conjunction with embodiment, the present invention is described in detail.

What the present invention adopted is a kind of indirect measure, does not directly measure sediment concentration in muddy water, but first by measuring dry husky mass M _s, clear water volume V _wand the method for the rear muddy water volume V of the two mixing, then calculate and determine silt density p _s, obtain silt density p _safterwards, then by actual measurement or demarcation, each point muddy water density p, clear water density p is measured _w, calculate and obtain corresponding silt volumetric concentration C _v.

The principle of the invention is as follows:

Silt is shared volume V in muddy water _sfor:

V _S＝V-V _W(1)

And silt density p in muddy water _scan calculate with following formula:

ρ _s＝M _s/V _s(2)

In muddy water, between Sediment quality and clear water quality, there is following relation:

ρ·V＝ρ _S·V _S+ρ _W·V _W(3)

And silt volume V _scan be expressed as:

V _S＝C _V·V(4)

Wherein, C _vfor silt volumetric concentration.

Clear water volume can be expressed as:

V _W＝V-V _S(5)

Formula (4) and formula (5) are substituted into formula (3) respectively:

ρ·V＝ρ _S·C _V·V+ρ _W(V-C _V·V)(6)

Silt volumetric concentration C is obtained after simplify processes is carried out to formula (6) _v:

$C_V=\frac{\mathrm{\ρ}-{\mathrm{\ρ}}_W}{{\mathrm{\ρ}}_S-{\mathrm{\ρ}}_W}---\left(7\right)$

Therefore, when measuring silt volumetric concentration, can by muddy water density p, clear water density p under variable concentrations condition _wwith silt density p in muddy water _smeasurement, adopt formula (7) to calculate silt volumetric concentration C _v.

If needed, formula (8) also can be adopted silt volumetric concentration C _vbe converted into silt content C' conventional in industry _m:

C' _M＝ρ _S·C _V(8)

In addition, consider that mineral density does not change because of particle size, temperature influence is also smaller, therefore can think (or have multiple different minerals matter at same mineral matter, but each mineral matter ratio is substantially constant) muddy water measurement of concetration in, this silt density p _sfor constant, need not again and again measure.

The inventive method comprises the following steps:

1) preparatory stage: survey calculation silt density p _s

1. mixed thoroughly by sand grain, the sand grain getting certain mass is on demand dried;

2. the rear Sediment quality M of required oven dry is weighed with balance or other high precision balance and weighing device _s;

3. silt scale being crossed quality all adds can in the orthobaric volume bucket of metered volume;

4. volume V will be measured _wclear water pour in regular barrel, stir, silt and clear water fully merged, until bubble-free around sand grain;

5. muddy water volume V is measured, by formula V _s=V-V _wcalculate solid particle shared volume V in muddy water of silt or identical mineral matter _s;

6. by formula ρ _s=M _s/ V _scalculate silt density p _s.

For improving measuring accuracy, muddy water volume V should be made close to volume bucket full scale as far as possible, and select measurement of concetration ρ high as far as possible _sbut must ensure that solid particle is fully blended in water, does not have bubble, muddy water can flow, automatically keep free, the horizontal water surface.

2) test phase: by measuring muddy water density p and clear water density p _w, calculate and determine silt volumetric concentration C _v

1. measure muddy water volume V and mass M, calculate muddy water density p;

2. the clear water density p identical with muddy water temperature is measured _w;

3. formula is utilized calculate silt volumetric concentration C _v; The silt content C' commonly used as needed _m, adopt formula C' _m=ρ _sc _vcalculate.

For different sediment concentrations, only need repeat three above-mentioned steps, and not need to return preparatory stage duplicate measurements silt density p _s.

Owing to adopting weight method to claim Sediment quality, muddy water quality and clear water quality, and when weighing, aerostatic buoyancy can affect measurement result, for ensureing measuring accuracy, should carry out aerostatic buoyancy correction when weighing.

The various embodiments described above are only for illustration of the present invention; the concrete implementation step that each stage and projects are measured and detailed rules and regulations all can change to some extent; on the basis of technical solution of the present invention; all improvement of carrying out indivedual implementation step and detailed rules and regulations according to the principle of the invention and equivalents, all should not get rid of outside protection scope of the present invention.

Claims (5)

1., by a method for muddy water density measure sediment concentration, it comprises the following steps:

1) preparatory stage: obtain silt density p _s

1. the Sediment quality M as husky sample is weighed _s, and put into a container, measure clear water volume V _w, pour in described container, stir into muddy water;

2. the muddy water volume V that 1. obtains of measuring process, calculates silt volume V in muddy water _s=V-V _w;

3. silt density p is calculated _s=M _s/ V _s;

2) test phase: the various mineral types of survey calculation and mineral matter ratio and step 1) in silt volumetric concentration C in the step muddy water that 1. described husky sample is consistent _v

1. weigh muddy water mass M to be measured, measure the volume V of muddy water to be measured;

2. muddy water density p=M/V and clear water density is calculated

3. calculate and obtain silt volumetric concentration

2. a kind of method by muddy water density measure sediment concentration as claimed in claim 1, is characterized in that: can by silt volumetric concentration C _vbe converted into silt content C' conventional in industry _m:

C' _M＝ρ _S·C _V。

3. a kind of method by muddy water density measure sediment concentration as claimed in claim 1 or 2, is characterized in that: described step 2) in silt volumetric concentration derivation as follows:

Silt is shared volume V in muddy water _sfor:

V _S＝V-V _W(1)

And silt density p in muddy water _sfor:

ρ _s＝M _s/V _s(2)

In muddy water, between Sediment quality and clear water quality, there is following relation:

ρ·V＝ρ _S·V _S+ρ _W·V _W(3)

And silt volume can be expressed as:

V _S＝C _V·V(4)

Clear water volume is expressed as:

V _W＝V-V _S(5)

Formula (4) and formula (5) are substituted into formula (3) respectively:

ρ·V＝ρ _S·C _V·V+ρ _W(V-C _V·V)(6)

Obtain after simplify processes is carried out to formula (6):

$C_V=\frac{\mathrm{\ρ}-{\mathrm{\ρ}}_W}{{\mathrm{\ρ}}_S-{\mathrm{\ρ}}_W}.\text{---}\left(7\right)$

4. a kind of method by muddy water density measure sediment concentration as claimed in claim 1 or 2, is characterized in that: obtain Sediment quality M _sduring with muddy water mass M to be measured, standard weighing-appliance is adopted to weigh acquisition.

5. a kind of method by muddy water density measure sediment concentration as claimed in claim 3, is characterized in that: obtain clear water volume V _wduring with muddy water volume V, the orthobaric volume cylinder bucket metering of metered volume is adopted to obtain.