CN105595395A - Calculation method for dehydration amount of thin plate cut-tobacco drier - Google Patents

Abstract

A calculation method for the dehydration amount of a thin plate cut-tobacco drier is characterized in that the feeding amount in a roller in a current cycle is obtained by cyclically calculating the average stay time of cut tobacco in the roller and the difference value between cumulative weights of the cut tobacco at an inlet of the roller in the current cycle and a previous cycle, the discharge amount of the cut tobacco is cyclically calculated according to the stay time, and then the accumulation amount in the roller is obtained; meanwhile, the average moisture content of the accumulation amount in the roller is calculated; the theoretical dehydration amount required by the accumulation amount in the roller in the current cycle is obtained according to the principle of conservation of mass and weight of dry bases of the cut tobacco before and after drying. The calculation method has the advantages that real-time calculation of the accumulation amount in the roller and the average moisture content of the accumulation amount is realized, calculation of the theoretical dehydration amount is more accurate, and real-time performance and precision of control over moisture of the cut tobacco at an outlet of the thin plate cut-tobacco drier are improved.

Description

A kind of computational methods of thin-plate cut-tobacco drier dehydrating amount

Technical field

The present invention relates to cigarette process, tobacco shreds drying equipment automation control technology especially and in tobacco silk producing procedures.

Background technology

Constantly perfect along with cigarette process, has proposed requirements at the higher level to the accuracy of product process control, and thin-plate cut-tobacco drier is systemKey equipment on silk thread, the precision of its process control has determined the inherent quality of finished cut tobacco. Therefore, thin-plate cut-tobacco drier is gone outThe control optimization of mouth moisture in cut tobacco becomes inevitable development trend.

At present, to the control of thin-plate cut-tobacco drier outlet moisture in cut tobacco be gather flow of tobacco that the electronic belt scale before cylinder detects andThe dehydrating amount that needs in the direct theory of computation of moisture in cut tobacco that infrared moisture meter detects, with in this simple, approximate reaction cylinderPipe tobacco situation to be processed, and regulate the controllable factors such as thin plate temperature, hot blast temperature, hot blast air quantity according to dehydrating amount, realize thinThe control of plate tobacco-dryer exit moisture in cut tobacco;

The control of pipe tobacco moisture content of outlet belongs to process control, and this makes the regulated variables such as thin plate temperature, hot blast temperature, hot blast air quantityWhat change affected is not the material in the interior a single point of cylinder or certain cross section, and the change of regulated variable can act in cylinder allPipe tobacco, in the time that flow of tobacco, moisture etc. fluctuate, for timely disturbance suppression, need to be compensated controlled quentity controlled variable accurately, willAs far as possible accurately knowing the situation of all pipe tobaccos to be processed in cylinder, is mainly buildup amount and all buildups when pipe tobacco in front rollThe average moisture of amount, calculates when the required dehydrating amount of pipe tobacco in front roll in real time and accurately with this.

Summary of the invention

In view of above technical background, content of the present invention is: by pipe tobacco mean residence time, current week in computation of Period cylinderPhase and a upper cycle cylinder porch pipe tobacco cumulative weight difference, obtain the inlet amount in current period cylinder, and according to stop timeBetween computation of Period pipe tobacco load, obtain buildup amount in cylinder with this; Calculate buildup amount average moisture content in cylinder simultaneously; Root againAccording to before dry, dry after pipe tobacco butt quality weight conservation principle, obtain the required theoretical dehydrating amount of buildup amount in current period cylinder,Computational methods the contents are as follows:

(1) symbol logo explanation

In order to narrate more clearly content of the present invention, first to below the variable symbol of using being described:

N: current period number;

T (n): current period gathers the moment;

T (n-1): a upper cycle gathers the moment;

M_a(n): current period gathers moment cylinder porch pipe tobacco cumulative weight;

M_a(n-1): a upper cycle gathers moment cylinder porch pipe tobacco cumulative weight;

M_in(n): current period inlet amount;

τ: pipe tobacco mean residence time in cylinder;

λ: entrance pipe tobacco is to the current computing cycle time;

M_in: accumulative total inlet amount in cylinder;

M_out: accumulative total load;

X (n): current period charging moisture content;

P₁: buildup amount average moisture content in cylinder;

P₂: moisture content is set in pipe tobacco outlet;

F: buildup amount in cylinder;

W: the required theoretical dehydrating amount of buildup amount in cylinder;

(2) cycle

In the PLC of control system, write this control program, such as being the cycle interruption program of a second interval time in PLCIn carry out this calculating, be exactly one second the interval time of one-period;

(3) residence Time Calculation

Calculate pipe tobacco mean residence time τ in cylinder_，Method is shown in described in detailed description of the invention (1);

(4) material state judgement

The cylinder porch pipe tobacco cumulative weight that gathers moment t (n) with current period deducts rolling of upper cycle collection moment t (n-1)The difference of cylinder porch pipe tobacco cumulative weight is as the inlet amount of current period: M_in(n)＝M_a(n)-M_a(n-1); SimultaneouslyCurrent period is gathered to the moisture in cut tobacco of moment t (n) as the charging moisture content X (n) of current period; Then according to current periodInlet amount is carried out material state judgement:

1)M_in(n) > 0: cylinder entrance has material, n=n+1, λ=λ+1;

2)M_in(n)=0: cylinder entrance is without material, n=n-1, λ=λ-1;

Boundary condition:

1)n＞τ：n＝n-1；

2) n≤τ: n value remains unchanged;

3)0≤λ≤τ；

4)n≥1；

(5) accumulative total inlet amount is calculated

Current period is counted to the cumulative accumulative total inlet amount obtaining in cylinder of all cycle inlet amounies in n;

$M\_in=\underset{i=1}{\overset{n}{\Σ}}{M}_{in}\left(i\right);$

(6) accumulative total load calculates

The inlet amount in certain cycle is left cylinder after the time of staying, calculates accumulative total load; :

$M\_out=\underset{j=0}{\overset{n-\mathrm{\λ}}{\Σ}}{M}_{in}\left(j\right);$

(7) the buildup amount in cylinder is calculated

Deduct accumulative total load by the accumulative total inlet amount in cylinder and obtain the buildup amount in cylinder;

$F=M\_in-M\_out=\underset{i=1}{\overset{n}{\Σ}}{M}_{in}\left(i\right)-\underset{j=0}{\overset{n-\mathrm{\λ}}{\Σ}}{M}_{in}\left(j\right);$

(8) in cylinder, buildup amount average moisture content calculates

In cylinder, buildup amount average moisture content is: $P_1=\underset{k=1}{\overset{n-(n-\mathrm{\λ})}{\Σ}}X\left(k\right)/\mathrm{\λ}=\underset{k=1}{\overset{\mathrm{\λ}}{\Σ}}X\left(k\right)/\mathrm{\λ};$

(9) in cylinder, the required theoretical dehydrating amount of buildup amount calculates

Pipe tobacco is in dry run, and drying medium transfers heat to pipe tobacco, and pipe tobacco internal moisture passes to dry with gasification modeMedium, what pipe tobacco reduced in cylinder is internal moisture, the dry matter weight (pipe tobacco butt quality weight) of dry forward and backward pipe tobaccoEquate, with the theorize computational methods of dehydrating amount of this conserva-tion principle.

That is: the butt quality weight of the interior buildup amount of the butt quality weight of buildup amount=dry back roll in dry front roll, calculates

Formula is as follows:

F*(1-P₁)＝(F-W)*(1-P₂)

In formula, F: buildup amount in cylinder; W: the required theoretical dehydrating amount of buildup amount in cylinder; P₁: in cylinder, buildup amount is flatAll moisture content; P₂: moisture content is set in pipe tobacco outlet;

Solving above-mentioned equation obtains: W=F (P₁-P₂)/(1-P₂)

That is: $W=\frac{\[\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{M}_{in}\left(i\right)-\underset{j=0}{\overset{n-\mathrm{\λ}}{\mathrm{\Σ}}}{M}_{in}\left(j\right)\]*\[\underset{k=1}{\overset{\mathrm{\λ}}{\mathrm{\Σ}}}X\left(k\right)/\mathrm{\λ}-P_2\]}{1-P_2}.$

By foregoing invention content, realize the real-time calculating to the buildup amount in cylinder and buildup amount average moisture content, make reasonThe calculating of opinion dehydrating amount has more high accuracy, has improved real-time and accuracy to the control of thin-plate cut-tobacco drier outlet moisture in cut tobacco.

Brief description of the drawings

Fig. 1 is the required theoretical dehydrating amount calculation flow chart of buildup amount in cylinder of the present invention.

Detailed description of the invention

For better narration above-mentioned purpose of the present invention, feature, do further concrete enforcement below in conjunction with summary of the invention.

A lot of details have been described so that fully understand the present invention in detailed description of the invention below, but the present invention is all rightAdopt other to be different from other modes described here and implement, therefore, the present invention is not limited to following public specific embodiment partyThe restriction of formula.

Detailed description of the invention is as follows:

(1) in cylinder, pipe tobacco mean residence time calculates

Under thin-plate cut-tobacco drier steady operation process condition, investigate respectively thin plate temperature T_w, hot blast temperature T_g, hot blast air quantity G_fThisThree regulated variables and these two disturbing factors of flow of tobacco Q, moisture content of cut tobaccos X are when to pipe tobacco, in cylinder, actual average stopsBetween impact. (motion of pipe tobacco in cylinder is not motion of single particle, but pipe tobacco particle swarm motion process, the time of staying is cigaretteThe mean residence time of silk particle swarm in cylinder, thin plate temperature, hot blast temperature, these three adjustable variables of hot blast air quantity simultaneouslyVariation also can impact the time of staying, wherein barrel temperature, hot blast temperature are by changing the axial moisture content of pipe tobacco and pipe tobaccoMass flow affects the time of staying):

For example give thin plate temperature T_wApply 10 DEG C of positive step and change, until while being stabilized in this parameter level, stopping cylinder entrance and establishStandby charging, starts segmentation simultaneously and picks out the pipe tobacco (the segmentation cycle is more short more accurate) at drum outlet place, treats in cylinder pipe tobacco after rolling,The gravimetric value of the every section of pipe tobacco picking out and moisture value are surveyed, be converted into butt pipe tobacco weight, add up and obtain in cylinderButt pipe tobacco hold-up H; The flow of tobacco again electronic belt scale entering before cylinder being detected is converted into entrance pipe tobacco butt qualityFlow F_S, be calculated as follows and obtain pipe tobacco actual average time of staying in cylinder:

τ＝H/F_S

Wherein τ is pipe tobacco actual average time of staying in cylinder, and H is butt pipe tobacco hold-up in cylinder, F_SFor entrance pipe tobacco buttMass flow

All the other factors: hot blast temperature T_g, hot blast air quantity G_fFlow of tobacco Q, moisture content of cut tobaccos X are actual in cylinder to pipe tobaccoThe impact of mean residence time has been tested by similar above-mentioned method;

Thin plate temperature T in test process_w, hot blast temperature T_g, hot blast air quantity G_f, flow of tobacco Q, moisture content of cut tobaccos X realityTesting data acquisition adopts the softwares such as SIMATICStep7, VB to carry out; Drum length L, diameter of cylinder D, cylinder slope s,Other influence factor recording equipment sensor detected value or the measured datas such as drum rotation speed z;

Use the Empirical rules algorithm of material time of staying in cylinder, in its algorithm, introduce current device process adjustments requiredIts dependent variable, in conjunction with the experimental data of above-mentioned collection, use the analysis such as Matlab, PLCSIM and simulation software to become introducingAmount changes the actual average time of staying impact in cylinder on pipe tobacco and carries out data analysis and Function Fitting, and solves coefficient, toThere is the coefficient of variable verify and revise, draw the meter of pipe tobacco mean residence time in the cylinder that is applicable to certain model cut-tobacco drierCalculation method;

(2) the programme-control platform that the manner is implemented

In the cycle interruption program block of PLC, write design control algolithm of the present invention, this concrete employing SIMATIC that implementsStep7 software, cycle interruption is OB32 (time interval is the cycle interruption tissue block of a second) for program block: in foregoing inventionThe step of holding, combination principle schematic diagram is write control program, adopts PLCSIM software to carry out emulation testing.

The foregoing is only the specific embodiment of the present invention, can not limit scope of the present invention with this, according to patent of the present invention ShenEquivalent variations and the modification please protection domain done, all should be included in technology covering scope of the present invention.

Claims (1)

1. computational methods for thin-plate cut-tobacco drier dehydrating amount, is characterized in that, on average stop by pipe tobacco in computation of Period cylinderTime, current period and a upper cycle cylinder porch pipe tobacco cumulative weight difference, obtain the inlet amount in current period cylinder,And according to time of staying computation of Period pipe tobacco load, obtain buildup amount in cylinder with this; Calculate the interior buildup amount of cylinder average simultaneouslyMoisture content; Again according to before dry, dry after pipe tobacco butt quality weight conservation principle, obtain buildup amount institute in current period cylinderNeed theoretical dehydrating amount, computational methods the contents are as follows:

(1) symbol logo explanation:

N: current period number;

T (n): current period gathers the moment;

T (n-1): a upper cycle gathers the moment;

M_a(n): current period gathers moment cylinder porch pipe tobacco cumulative weight;

M_a(n-1): a upper cycle gathers moment cylinder porch pipe tobacco cumulative weight;

M_in(n): current period inlet amount;

τ: pipe tobacco mean residence time in cylinder;

λ: entrance pipe tobacco is to the current computing cycle time;

M_in: accumulative total inlet amount in cylinder;

M_out: accumulative total load;

X (n): current period charging moisture content;

P₁: buildup amount average moisture content in cylinder;

P₂: moisture content is set in pipe tobacco outlet;

F: buildup amount in cylinder;

W: the required theoretical dehydrating amount of buildup amount in cylinder;

(2) cycle

In the PLC of control system, write this control program, such as being the cycle interruption program of a second interval time in PLCIn carry out this calculating, be exactly one second the interval time of one-period;

(3) residence Time Calculation

Calculate pipe tobacco mean residence time τ in cylinder;

(4) material state judgement

The cylinder porch pipe tobacco cumulative weight that gathers moment t (n) with current period deducts rolling of upper cycle collection moment t (n-1)The difference of cylinder porch pipe tobacco cumulative weight is as the inlet amount of current period: M_in(n)＝M_a(n)-M_a(n-1); SimultaneouslyCurrent period is gathered to the moisture in cut tobacco of moment t (n) as the charging moisture content X (n) of current period; Then according to current periodInlet amount is carried out material state judgement:

1)M_in(n) > 0: cylinder entrance has material, n=n+1, λ=λ+1;

2)M_in(n)=0: cylinder entrance is without material, n=n-1, λ=λ-1;

Boundary condition:

1)n＞τ：n＝n-1；

2) n≤τ: n value remains unchanged;

3)0≤λ≤τ；

4)n≥1；

(5) accumulative total inlet amount is calculated

Current period is counted to the cumulative accumulative total inlet amount obtaining in cylinder of all cycle inlet amounies in n;

$M\_in=\underset{i=1}{\overset{n}{\Σ}}{M}_{in}\left(i\right);$

(6) accumulative total load calculates

The inlet amount in certain cycle is left cylinder after the time of staying, calculates accumulative total load; :

$M\_out=\underset{j=0}{\overset{n-\mathrm{\λ}}{\Σ}}{M}_{in}\left(j\right);$

(7) the buildup amount in cylinder is calculated

Deduct accumulative total load by the accumulative total inlet amount in cylinder and obtain the buildup amount in cylinder;

$F=M\_in-M\_out=\underset{i=1}{\overset{n}{\Σ}}{M}_{in}\left(i\right)-\underset{j=0}{\overset{n-\mathrm{\λ}}{\Σ}}{M}_{in}\left(j\right);$

(8) in cylinder, buildup amount average moisture content calculates

In cylinder, buildup amount average moisture content is: $P_1=\underset{k=1}{\overset{n-(n-\mathrm{\λ})}{\Σ}}X\left(k\right)/\mathrm{\λ}=\underset{k=1}{\overset{\mathrm{\λ}}{\Σ}}X\left(k\right)/\mathrm{\λ};$

(9) in cylinder, the required theoretical dehydrating amount of buildup amount calculates

Pipe tobacco is in dry run, and drying medium transfers heat to pipe tobacco, and pipe tobacco internal moisture passes to dry with gasification modeMedium, what pipe tobacco reduced in cylinder is internal moisture, the dry matter weight of dry forward and backward pipe tobacco equates, with this conservationThe theorize computational methods of dehydrating amount of principle;

That is: the butt quality weight of the interior buildup amount of the butt quality weight of buildup amount=dry back roll in dry front roll, calculatesFormula is as follows:

F*(1-P₁)＝(F-W)*(1-P₂)

In formula, F: buildup amount in cylinder; W: the required theoretical dehydrating amount of buildup amount in cylinder; P₁: in cylinder, buildup amount is flatAll moisture content; P₂: moisture content is set in pipe tobacco outlet;

Solving above-mentioned equation obtains: W=F (P₁-P₂)/(1-P₂)

That is: $W=\frac{{\[\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{M}_{in}\left(i\right)-\underset{j=0}{\overset{n-\mathrm{\λ}}{\mathrm{\Σ}}}{M}_{in}\left(j\right)\]}^{*}\[\underset{k=1}{\overset{\mathrm{\λ}}{\mathrm{\Σ}}}X\left(k\right)/\mathrm{\λ}-P_2\]}{1-P_2}.$