CN101446833A - Method for obtaining liquid medicine in fixed amount - Google Patents

Abstract

A method for obtaining liquid medicine in fixed amount belongs to the technical field of chemical engineering and medical treatment, and particularly relates to a method for obtaining liquid medicine in fixed amount. The method provided by the invention is characterized in that a control system provided with a control unit is adopted; by testing the experimental data released by a plurality of groups of liquid to be obtained in a storage container, a cubic curve of the valve opening and discharging time required by a random amount of liquid medicine at a certain liquid level is proposed; a binary function describing a random amount liquid medicine discharged from a random liquid level is derived therefrom; time required for the addition of a certain amount of liquid medicine at the current liquid level can be computed through the function; and the time determines when to open the valve, so that accurate acquisition of the liquid medicine can be fulfilled. The method provided by the invention greatly reduces the effect of the accuracy of a liquid level sensor on the results, is free of sophisticated hardware, and has the advantages of high accuracy, long service life and good economy when being embedded in a control system. The invention can be widely applied to liquid medicine filling, acquisition of a fixed amount of liquid medicine and accurate proportion of various liquid medicines, and particularly exhibits obvious advantages when dealing with highly corrosive liquid medicine.

Description

A kind of quantitative acquisition methods of soup

Technical field

The invention belongs to chemical industry, field of medical technology, particularly a kind of quantitative acquisition methods of soup.

Background technology

In chemical industry and medical field, usually relate to the can of soup, a certain amount of soup obtain and multiple soup carries out accurate proportioning.At present, the commonsense method of quantitatively obtaining of soup is to take out soup with certain method in the reservoir vessel of constant cross-section, and by liquid level in the liquid level sensor detection receptacle, the product that amasss according to the variation and the container section of liquid level obtains the volume of the soup that obtains again.The kind of liquid level sensor has contact and contactless two classes, and wherein contact has float-ball type, static pressure type etc., contactless ultrasonic liquid level sensor, the fibre optic liquid level sensor etc. of mainly containing.The existing precision of contact liquid level sensor is not high, and common precision has 1%, 2%, 5% etc. of range.The floorage that error is stored container especially in the commonsense method that present soup quantitatively obtains is amplified exponentially, in some comparatively accurate systems, obviously can not meet the demands, and that more high-precision liquid level sensor needs is customized specially, and price is very expensive.In addition, may there be vibrations in reservoir vessel, the fluctuation that this just causes liquid level, and the liquid level error that records like this is just bigger.It is good slightly that contactless liquid level sensor is compared contact liquid level sensor precision, but the soup of most high concentrations, severe corrosive top all easily produces " atomizing " phenomenon, for example the acid mist of the hydrochloric acid of high concentration, the formation of nitric acid top can produce it like this and disturb, so that measure inaccurate.If obtain high strength corrosivity soup with the high-precision measuring pump, though precision can reach 0.1%, even 0.05%, but the temperature of media fluid, viscosity, the particle situation is very big to the influence of high-precision measuring pump, and high-precision volume pump costs an arm and a leg, and the life-span is short.

Summary of the invention

The objective of the invention is at above-mentioned the deficiencies in the prior art, provide a kind of soup accurate acquisition methods, be embedded in the control system, reduce cost, improve precision, life-span and the reliability of system.

The object of the present invention is achieved like this: a kind of accurate acquisition methods of soup, be stored in the liquid in the certain container of specification, as long as starting altitude is identical, under the state of nature of action of gravity, release by position, the certain valve port of pore size, from identical original state, the time of emitting certain quantity of fluid is changeless principle.Through the many groups of test experimental data, carry out cubic polynomial with least square method (Ordinary Least Square) and simulate begin to release out the functional relation of amount of liquid medicine and the time of releasing from certain initial liquid level h0, derive from any liquid level the functional relation of the amount of liquid medicine of releasing and time again.Control the switching time of valve port according to this functional relation and obtain the purpose of soup to reach precision.Its concrete grammar is as follows:

The first step: by test the characteristic equation of releasing that match drug liquid is released in reservoir vessel

(1) measures and wait to obtain the liquid density p, constant cross-section reservoir vessel sectional area S;

(2) will soup be obtained pack in the reservoir vessel, liquid level reaches the limit liquid level of container, the output of the float-ball type liquid level sensor of LOAD CELLS, general precision is incorporated into control system, treat liquid level stabilizing after, in control system, read in the value h of common liquid level sensor ₀, and open the bleed outlet valve and soup is released place temporary container on the LOAD CELLS, the real-time weight m after per elapsed time interval of delta t will be removed the peel continuously ₁, m ₂..., m _nNote;

(3) with least square method n is organized data $(\frac{{\mathrm{<figure-callout\; id="1"\; label="m"\; filenames="A200810233092E00081.png"\; state="\{\{state\}\}">m</figure-callout>}}_1}{\mathrm{\&rho;S}},\mathrm{\&Delta;t}),(\frac{{\mathrm{<figure-callout\; id="2"\; label="m"\; filenames="A200810233092E00081.png"\; state="\{\{state\}\}">m</figure-callout>}}_2}{\mathrm{\&rho;S}},2\mathrm{\&Delta;t}),\&CenterDot;\&CenterDot;\&CenterDot;,(\frac{m_n}{\mathrm{\&rho;S}},\mathrm{n\&Delta;t})$ Carry out the cubic curve match, draw equation:

t(h)＝k ₃h ³+k ₂h ²+k ₁h+k ₀

In the formula: k ₀, k ₁, k ₂, k ₃-the multinomial coefficient that goes out with least square fitting

The liquid-column height of soup in reservoir vessel of h-be acquired, by $h=\frac{m}{\mathrm{\&rho;S}}$ Or $h=\frac{V}{S}$ Obtain

T-from liquid level h ₀Add the required time of soup of quality m

(4) release the soup that begins to obtain volume V from any liquid level H and need the soup of the duration of valve opening T characteristic equation of releasing:

$T(H,V)=t(h_0-(H-\frac{V}{S}))-t(h_0-H)$

In the formula: the cubic function relation that obtains in t-(3)

H-before quantitatively obtaining, the liquid level in the reservoir vessel

The medicine liquid volume of V-quantitatively obtain

The cross-sectional area of S-reservoir vessel

h ₀The liquid level value that liquid level sensor reads in-(2)

Second step: realize quantitatively obtaining of soup by the soup characteristic equation of releasing

The above-mentioned characteristic equation of releasing of this soup is implanted in the control system, read in the real-time liquid level H of liquid level sensor by control module, again according to the required medicine liquid volume V that obtains, obtain the opening time T of bleed outlet valve with the characteristic equation of releasing, accurately the opening time of by-pass valve control is that T can finish quantitatively obtaining of soup.

After the present invention adopts technique scheme, obtain a certain amount of soup indirectly by the control duration of valve opening, reduced of the influence of the precision of liquid level sensor significantly to the result, can be embedded in the control system, directly replace and test current liquid level H by liquid level sensor, and calculate target liquid level H-V/S according to amount of liquid medicine V and come the soup adding method of the open and close of control electromagnetic valve, existing other guide in the existing control system there is not influence, easy and simple to handle.Owing to utilized the clocking capability of control system itself, structurally do not increased any hardware, but significantly improved the precision that soup quantitatively obtains.The present invention can be widely used in various liquid medicine filling in chemical industry, the medical industry, quantitatively obtain and matching system in, more have a clear superiority at the severe corrosive soup.

Description of drawings

Fig. 1 is the device front view of invention;

Fig. 2 is the testing apparatus front view;

Fig. 3 is the liquid level position graph of a relation;

Among the figure: 1-preceding corrosivity soup to be added; 2-container cover; 3-bleeder vent; 4-resistant material shell floating head type general precision liquid level sensor; 5-raise the nose above water to breathe; 6-corrosion-resistant diaphragm solenoid valve; 7-band signal output Precision Electronics Balance; 8-weighing container; 9-catheter; The soup reservoir vessel to be added of 10-constant cross section.

Embodiment

Below in conjunction with drawings and Examples, further specify as follows to the quantitative acquisition methods of soup involved in the present invention:

The method enforcement of the present invention of embodiment 1 usefulness is to the quantitative interpolation of 800 milliliter 45% soda bath

As Fig. 1-shown in Figure 3, constant cross-section soup reservoir vessel inner bottom surface and fluid mouth of pipe vertical range are 25cm, fluid conduit mouth internal diameter Φ 15mm.Present embodiment utilizes the Siemens Programmable Logic Controller CPU313C, the liquid level sensor UTB 2235 that carry in the Chemical Engineering Process Control system (range 500mm precision ± 5mm), realize the quantitative interpolation of 800 milliliter 45% soda bath by the inventive method, its method step is as follows:

The first step: simulate the characteristic equation of releasing that 45% soda bath is released in specification reservoir vessel shown in Figure 1 by test

(1) measures and wait to obtain liquid density p=1.48g/cm ², constant cross-section soup reservoir vessel sectional area S=400cm ²

(2) will soup be obtained pack in the reservoir vessel 10, liquid level is near the limit liquid level of container, the output of LOAD CELLS is incorporated into Programmable Logic Controller, treat that liquid level is basicly stable after, programming is read in the value h of liquid level sensor 4 from corresponding analog quantity input end in Programmable Logic Controller ₀=48cm, and opens solenoid valve 6 continuously will soup be obtained be released and is placed container 8 on the LOAD CELLS 7, the real-time weight m after per elapsed time interval of delta t=5s will remove the peel ₁, m ₂..., m ₂₄Note and be followed successively by: 1.53Kg, 2.97Kg, 4.37Kg, 5.74Kg, 7.11Kg, 8.43Kg, 9.76Kg, 11.06Kg, 12.31Kg, 13.56Kg, 14.79Kg, 16.00Kg, 17.24Kg, 18.29Kg, 19.44Kg, 20.49Kg, 21.57Kg, 22.71Kg, 23.76Kg, 24.67Kg, 25.66Kg, 26.66Kg, 27.62Kg, 28.39Kg;

(3) with least square method to 24 groups of data: (2.59,5), (5.01,10), (7.38,15), (9.70,20), (12.01,25), (14.24,30), (16.49,35), (18.69,40), (20.80,45), (22.90,50), (24.98,55), (27.03,60), (29.13,65), (30.09,70), (32.84,75), (34.61,80), (36.43,85), (38.36,90), (40.14,95), (41.70,100), (43.35,105), (45.03,110), (46.65,115), (47.95,120) carry out the cubic curve match, by following formula:

$\left(\begin{array}{cccc}n& \mathrm{\&Sigma;}(m_i/\mathrm{\&rho;S})& \mathrm{\&Sigma;}{(m_i/\mathrm{\&rho;S})}^2& \mathrm{\&Sigma;}{(m_i/\mathrm{\&rho;S})}^3\\ \mathrm{\&Sigma;}(m_i/\mathrm{\&rho;S})& \mathrm{\&Sigma;}{(m_i/\mathrm{\&rho;S})}^2& \mathrm{\&Sigma;}{(m_i/\mathrm{\&rho;S})}^3& \mathrm{\&Sigma;}{(m_i/\mathrm{\&rho;S})}^4\\ \mathrm{\&Sigma;}{(m_i/\mathrm{\&rho;S})}^2& \mathrm{\&Sigma;}{(m_i/\mathrm{\&rho;S})}^3& \mathrm{\&Sigma;}{(m_i/\mathrm{\&rho;S})}^4& \mathrm{\&Sigma;}{(m_i/\mathrm{\&rho;S})}^5\\ \mathrm{\&Sigma;}{(m_i/\mathrm{\&rho;S})}^3& \mathrm{\&Sigma;}{(m_i/\mathrm{\&rho;S})}^4& \mathrm{\&Sigma;}{(m_i/\mathrm{\&rho;S})}^5& \mathrm{\&Sigma;}{(m_i/\mathrm{\&rho;S})}^6\end{array}\right)\left(\begin{array}{c}{k}_0\\ k_1\\ k_2\\ {\mathrm{<figure-callout\; id="3"\; label="k"\; filenames="A200810233092E00081.png"\; state="\{\{state\}\}">k</figure-callout>}}_3\end{array}\right)=\left(\begin{array}{c}\mathrm{\&Sigma;}{t}_i\\ \mathrm{\&Sigma;}(m_i/\mathrm{\&rho;S})t_i\\ \mathrm{\&Sigma;}{(m_i/\mathrm{\&rho;S})}^2{t}_i\\ \mathrm{\&Sigma;}{(m_i/\mathrm{\&rho;S})}^3{t}_i\end{array}\right)$ ..①

In the formula: n-data space size is 24 among this embodiment

m _i-by Precision Electronics Balance claim quality, i=1 wherein, 2 ..., 24

ρ-wait to obtain soup density is 1.48g/cm among this embodiment ²

S-soup reservoir vessel cross-sectional area is 400cm among this embodiment ²

k ₀, k ₁, k ₂, k ₃-the multinomial coefficient that goes out with least square fitting

t _i-with m _iCorresponding releases the soup time, and t is arranged _i=i Δ t, Δ t is that 5s solves (k among this embodiment ₀k ₁k ₂k ₃) ^T=(0.5599551 2.1020734 0.0008469 0.0001573) ^T, obtain equation:

t＝0.0001573h ³+0.0008469h ²+2.1020734h-0.5599551....................②

In the formula: the liquid-column height of soup in reservoir vessel of h-be acquired

T-from liquid level h ₀Add the required time of soup of quality m

(4) in conjunction with Fig. 3,2. releasing the soup that begins to obtain volume V from any liquid level H by equation needs the soup of the duration of valve opening T characteristic equation of releasing:

$T(H,V)=t(h_0-(H-\frac{V}{S}))-t(h_0-H)$

$=0.0001573\&times;{(48-H+\frac{V}{400})}^3+0.0008469\&times;{(48-H+\frac{V}{400})}^2+2.1020734\&times;(48-H+\frac{V}{400})$

$-[0.0001573\&times;{(48-H)}^3+0.0008469\&times;{(48-H)}^2+2.1020734\&times;(48-H)]$

In the formula: liquid level before H-interpolation soup should have H≤h ₀, h among this embodiment ₀=48cm

The medicine liquid volume of the interpolation of V-required should have V＜SH, S=400cm among this embodiment ²

T-from liquid level is H, and obtaining volume is the needed duration of valve opening of soup of V

Second step: realize that by the soup characteristic equation of releasing 800 milliliter 45% soda bath quantitatively obtains

The above-mentioned characteristic equation of releasing of this soup is implanted in the control system, read in liquid level sensor UTB 2235 real-time liquid level H by Siemens Programmable Logic Controller CPU313C, again according to the required medicine liquid volume V that obtains, obtain the opening time T of bleed outlet valve with the characteristic equation of releasing, accurately the opening time of by-pass valve control is that T can finish quantitatively obtaining of soup, in order to guarantee data stability, carried out three soda baths below and quantitatively obtained.

1. quantitatively obtain for the first time: reading in liquid level is 47.8cm, and error ± 0.5cm calculates duration of valve opening T=4.210s by required medicine liquid volume 800mL, the opening time of control solenoid valve 6 is 4.210s, take out the soup that obtains and measure with graduated cylinder, volume is 806mL, and error is 0.75%;

2. quantitatively obtain for the second time: reading in liquid level is 46.2cm, and error ± 0.5cm calculates duration of valve opening T=4.210s by required medicine liquid volume 800mL, the opening time of control solenoid valve 6 is 4.221s, take out the soup that obtains and measure with graduated cylinder, volume is 796mL, and error is 0.5%;

3. quantitatively obtain for the third time: reading in liquid level is 43.8cm, and error ± 0.5cm calculates duration of valve opening T=4.210s by required medicine liquid volume 800mL, the opening time of control solenoid valve 6 is 4.248s, take out the soup that obtains and measure with graduated cylinder, volume is 792mL, and error is 1%.

More than the error range quantitatively obtained for three times be: 0.5%～1%.

The existing commonsense method of embodiment 2 usefulness is quantitatively obtained 800 milliliter 45% soda bath

Present embodiment is quantitatively to obtain with the soda bath of existing commonsense method to 800 milliliter 45%, can be used as a Comparative Examples of the inventive method, still utilize device shown in Figure 1, different is that this method is directly to test current liquid level H by liquid level sensor, and come the soup adding method of the open and close of control electromagnetic valve to finish quantitatively according to amount of liquid medicine V calculating target liquid level H-V/S and obtain, also carried out three soda baths below and quantitatively obtained.

1. quantitatively obtain for the first time: reading in liquid level is 47.8cm, error ± 0.5cm, calculate target liquid level H-V/S=45.8cm by required medicine liquid volume 800mL, opens solenoid valve 6 also reads the value of liquid level sensor 4 in real time, when it closes solenoid valve 6 during for 45.8cm, take out the soup that obtains and measure with graduated cylinder, volume is 912mL, and error is 14%;

2. quantitatively obtain for the second time: reading in liquid level is 45.6cm, error ± 0.5cm, calculate target liquid level H-V/S=43.6cm by required medicine liquid volume 800mL, opens solenoid valve 6 also reads the value of liquid level sensor 4 in real time, when it closes solenoid valve 6 during for 43.6cm, take out the soup that obtains and measure with graduated cylinder, volume is 728mL, and error is 9%;

3. quantitatively obtain for the third time: reading in liquid level is 43.8cm, error ± 0.5cm, calculate target liquid level H-V/S=41.8cm by required medicine liquid volume 800mL, opens solenoid valve 6 also reads the value of liquid level sensor 4 in real time, when it closes solenoid valve 6 during for 41.8cm, take out the soup that obtains and measure with graduated cylinder, volume is 742mL, and error is 7.25%.

The existing commonsense method of above-mentioned three usefulness is 7.25%～14% to the error range that 800 milliliter 45% soda bath quantitatively obtains, and obviously its error is far longer than the error of the quantitative acquisition methods of soup of the present invention.

Claims (1)

1. the quantitative acquisition methods of a soup is characterized in that method step is as follows:

The first step: by test the characteristic equation of releasing that match drug liquid is released in reservoir vessel

(1) measures and wait to obtain the liquid density p, constant cross-section reservoir vessel sectional area S;

(2) will soup be obtained pack in the reservoir vessel, liquid level reaches the limit liquid level of container, the output of the float-ball type liquid level sensor of LOAD CELLS, general precision is incorporated into control system, after treating liquid level stabilizing, in control system, read in the value h0 of common liquid level sensor, and open the bleed outlet valve and soup is released place temporary container on the LOAD CELLS, the real-time weight m after per elapsed time interval of delta t will be removed the peel continuously ₁, m ₂..., m _nNote;

(3) with least square method n is organized data

Carry out the cubic curve match, draw equation:

t(h)＝k ₃h ³+k ₂h ²+k ₁h+k ₀

In the formula: k ₀, k ₁, k ₂, k ₃-the multinomial coefficient that goes out with least square fitting

The liquid-column height of soup in reservoir vessel of h-be acquired, by $h=\frac{m}{\mathrm{\&rho;S}}$ Or $h=\frac{V}{S}$ Obtain

T-from liquid level h ₀Add the required time of soup of quality m

(4) release the soup that begins to obtain volume V from any liquid level H and need the soup of the duration of valve opening T characteristic equation of releasing:

$T(H,V)=t(h_0-(H-\frac{V}{S}))-t(h_0-H)$

In the formula: the cubic function relation that obtains in t-(3)

H-before quantitatively obtaining, the liquid level in the reservoir vessel

The medicine liquid volume of V-quantitatively obtain

The cross-sectional area of S-reservoir vessel

h ₀The liquid level value that liquid level sensor reads in-(2)

Second step: realize quantitatively obtaining of soup by the soup characteristic equation of releasing

The above-mentioned characteristic equation of releasing of this soup is implanted in the control system, read in the real-time liquid level H of liquid level sensor by control module, again according to the required medicine liquid volume V that obtains, obtain the opening time T of bleed outlet valve with the characteristic equation of releasing, accurately the opening time of by-pass valve control is that T can finish quantitatively obtaining of soup.

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