CN106055735A - Model for stable feeding of powder agent filling in long and thin metal tube - Google Patents

Abstract

The invention provides a model for stable feeding of powder agent filling in a long and thin metal tube and belongs to the technical field of powders. Aiming at the problem that the metal tube will be plugged if an excessive amount of powder agent is fed each time during the filling of the powder agent into the long and thin metal tube, the invention establishes the feeding amount control model based on a vibrating screen. The model is established by a step A of infinitesimal body mechanical analysis of an agent arc, a step B of infinitesimal body kinematics analysis of the agent arc and a step C of establishment of the stable feeding model based on the vibrating screen. According to the model established in the model and in combination with actual feeding amount demands, parameter optimization can be conducted to a vibration frequency and amplitude of the vibrating screen. Experimental verification results show that the model provided by the invention can effectively implement the stable feeding of the powder agent filling in the long and thin metal tube.

Description

A kind of stably feeding model of slender type metal tube powder body medicament filling

Technical field

The invention belongs to powder technology field, relate to the stably feeding mould of a kind of slender type metal tube powder body medicament filling Type.

Background technology

In primacord produces, need powder body medicament to be encased in slender type metal tube.Granularity due to pharmacy particle The least, particle mean size is less than 18 μm, and therefore the mobility of pharmacy particle itself is very poor；The internal diameter of metal tube is little simultaneously, Er Qiechang Degree is long, therefore the pharmacy particle of certain mass is encased in slender type metal tube, and to meet the index requests such as line density be to lead One difficult point of quick-fried rope production process.Simultaneously as the adhesiveness of powder body material is relatively strong, if once put in poison during filling Amount then can block tremie pipe too much.Therefore it is required that feeding coal should be stablized controlled during filling.

Under outside effect of vibration, the mobile performance of powder body can be improved.But, owing to variable grain substance system exists Under the effect of different factors, its kinetic characteristic differs greatly.It is necessary to combine concrete actual application problem, the flowing to powder body Study with Packing Problems.

Realize stably feeding based on vibrosieve, mainly by horizontal vibration by the powder body medicament of certain mass in screen cloth with One more slowly dispensing speed put in loading hopper, to guarantee that what medicament loaded smoothly completes.In whole blanking process, medicine Agent is presented in screen cloth in the way of scattered heap.Under static state, due to the agglomerating force between the granule of composition medicament and granule Between internal friction so that the medicament in screen cloth shows certain aggregating characteristic, can make the medicament being at sieve screen apertures Burl encircles, and is in the pharmacy particle at sieve screen apertures and also will not spill from screen cloth because of the action of gravity of medicament self.By giving sieve Net applies the effect of vibration in a horizontal direction, overcomes the agglomerating force between pharmacy particle, between destroying by pharmacy particle The aggregating characteristic that agglomerating force and internal friction are formed, allows a small amount of medicament separate from medicament aggregation, thus at gravity In the way of free settling, loading hopper is entered, the most repeatedly, it is achieved whole Vibrated baiting process under the effect of acceleration.

Summary of the invention

In view of this, it is an object of the invention to propose the stably feeding mould of a kind of slender type metal tube powder body medicament filling Type, the method is for when loading slender metal pipe by powder body medicament, and one-time feeding can cause metal tube to block this problem too much, The model set up by the present invention, in conjunction with actual discharge quantity demand, the parameter carrying out shaker vibration frequency and amplitude is excellent Change, by horizontal vibration, the powder body medicament of certain mass in screen cloth put in loading hopper with a more slow dispensing speed, To guarantee that what medicament loaded smoothly completes.

For reaching above-mentioned purpose, the present invention provides following technical scheme:

The stably feeding model of a kind of slender type metal tube powder body medicament filling, comprises the following steps:

Step A: the micro unit mechanical analysis of medicament arch

Consider the micro unit that medicament as shown in Figure 1 encircles, take the micro unit containing the scope of freedom

Step A-1: solve the gravity of micro unit

Gravity (the W of micro unit_arch) can be approximately:

W_arch=π (r₀sinθ)²δ_cρ_sg

Wherein r₀For sieve aperture cross section inner circle radius；θ is inclination angle, sieve aperture cross section；δ_cFor micro unit height；ρ_sPile up close for medicament Degree；G is acceleration of gravity.

Step A-2: analyze applied external force F being applied to vibrosieve_w

Wanting to destroy arch, make pharmacy particle fall, applied external force should be greater than open yield stress f_c, it may be assumed that

F_w＞ f_c

Step A-3: analyze frictional force F of micro unit and chamber wall_m

Micro unit should be less than micro unit gravity with the frictional force of chamber wall, it may be assumed that

F_m=μ F_w＜ W_arch

Wherein μ is the coefficient of friction of medicament and chamber wall

Step B: micro unit kinematics analysis

If the frequency of vibrosieve horizontal vibration is f, amplitude is L, and the quality of horizontal vibration device is m, and vibration uses cylinder The mode of vibration, is had by static at cylinder during motion:

$\frac{1}{2}{\mathrm{at}}^2=L$

Wherein a is the cylinder acceleration by static divertical motion, and t is the time required for cylinder moving distance L

Step B-1: solve acceleration of motion a of cylinder

Due to

T=1/2f

Acceleration of motion a that can try to achieve cylinder is:

A=8f²L

Step B-2: solve the maximal rate of cylinder moving

v₀=4fL

Step B-3: solve applied external force F being applied to vibrosieve_w

According to theorem of impulse: mv=Ft, the power in horizontal direction suffered by screen cloth Chinese medicine can be obtained:

F_w=mv₀/ 2t=4mf²L

Step C: set up stably feeding model based on vibrosieve:

Step C-1: consider to be administered shown in Fig. 2 mouth structure, analyze mass flow, medicament when cylinder bottom opening flows out, Set mass flow empirical equation as:

$q_m={\mathrm{C\ρ}}_s\sqrt{g}{(D_0-{\mathrm{kd}}_p)}^{2.5}$

In formula, C and k is constant, relevant with internal friction angle, and its value can be through measuring；d_pParticle diameter for pharmacy particle.

Step C-2: comprehensive the most various, can obtain lower dose Q and frequency of vibration f, the relation of amplitude L, then can set up Stably feeding model based on vibrosieve:

$\left\{\begin{array}{c}Q={\mathrm{C\ρ}}_s\sqrt{g}{\left(D_0-{\mathrm{kd}}_p\right)}^{2.5}{\mathrm{ft}}_z\\ \mathrm{\π}{\left(r_0\sin \mathrm{\θ}\right)}^2{\mathrm{\δ}}_c{\mathrm{\ρ}}_{s}g>4{\mathrm{mf}}^{2}L>f_c\end{array}\right.$

The beneficial effects of the present invention is:

The model set up according to the present invention, combines the discharge quantity demand of reality, carries out shaker vibration frequency and amplitude Parameter optimization, it is possible to achieve the stably feeding in the filling of slender type metal tube powder body medicament, and achieve and preferably load effect.

Accompanying drawing explanation

In order to make the purpose of the present invention, technical scheme and beneficial effect clearer, the present invention provides drawings described below to carry out Illustrate:

The micro unit schematic diagram of Fig. 1 medicament arch

Fig. 2 is administered mouth structure schematic diagram

Fig. 3 puts in poison the relation simulation curve of speed and frequency of vibration

Fig. 4 puts in poison the relation simulation curve of speed and amplitude

Detailed description of the invention

Below in conjunction with accompanying drawing and subordinate list, the preferred embodiments of the present invention are described in detail.

The stably feeding model of slender type metal tube powder body medicament of the present invention filling, comprises the following steps: step The micro unit mechanical analysis of A: medicament arch；Step B: the micro unit kinematics analysis of medicament arch；Step C: set up based on vibrosieve Stably feeding model.

Step A: the micro unit mechanical analysis of medicament arch

Step A-1: in this step, the micro unit encircleed medicament with reference to Fig. 1 carries out gravimetric analysis.Consider medicine as shown in Figure 1 The micro unit of agent arch, takes the micro unit containing the scope of freedom, from Mohr Coulomb law, and More's stress of any point in powder body Circle is when the lower section of effective yield focus, and powder body will remain static；In powder body, the Mohr's stress circle of certain point is with the most in the wrong When taking trajectory tangential, powder body is in critical flow or flow regime.Owing to the principal stress on Free Surface and shear stress are zero, This minimum principal stress being equivalent on Mohr's circle is zero, and shear stress is zero, and maximum principal stress is equal to open yield stress State.

Gravity (the W of micro unit_arc ^h) W can be approximately:_arch=π (r₀sinθ)²δ_cρ_sg

Step A-2: in whole blanking process, pharmacy particle is placed on screen cloth in the way of scattered heap.In resting state Under, when mesh opening size is in certain limit, due to the work of the internal friction between the agglomerating force between pharmacy particle and granule With, the pharmacy particle knot arch being at sieve screen apertures can be made so that granule will not spill from screen cloth because of the action of gravity of self.

Wanting to destroy arch, make pharmacy particle fall, applied external force should meet F_w＞ f_c

Step A-3: micro unit should be less than micro unit gravity with the frictional force of chamber wall, it may be assumed that F_m=μ F_w＜ W_arch

Step B: micro unit kinematics analysis

This step is administered with reference to shown in Fig. 2 mouth structure, when screen cloth being applied the effect of vibration in a horizontal direction, Direct stress is more than open yield stress, and granule arch is destroyed.At this moment, part pharmacy particle under the effect of acceleration of gravity with from Loading hopper is entered by the mode settled.Fig. 2 show administration mouth structure schematic diagram, different from fluid, mass flow q of granule_m Unrelated with height H and diameter D；With opening size D₀, bulk density ρ of medicament_s, gravity acceleration g relevant.

Power according in horizontal direction suffered by known parameters and data calculating screen cloth Chinese medicine:

F_w=mv₀/ 2t=4mf²L

Step C: according to known parameters, solves unknown parameter, sets up stably feeding model based on vibrosieve

$\left\{\begin{array}{c}Q={\mathrm{C\ρ}}_s\sqrt{g}{\left(D_0-{\mathrm{kd}}_p\right)}^{2.5}{\mathrm{ft}}_z\\ \mathrm{\π}{\left(r_0\sin \mathrm{\θ}\right)}^2{\mathrm{\δ}}_c{\mathrm{\ρ}}_{s}g>4{\mathrm{mf}}^{2}L>f_c\end{array}\right.$

Embodiment

In the present embodiment, by emulation and test data, model validation is carried out checking to analyze.

1. combine actual application settings parameter

In the embodiment of the present invention, selected powder body pharmacy particle dissipates bulk density ρ_sFor 0.362g/ml, it is administered nozzle aperture diameter D₀For 4.2mm, radius r₀Long 10mm, opening inclination angle theta is 5 °, hole depth δ_cFor 1.4mm, it is likely to occur blocking for critical with hopper outlet Condition, be calculated guarantee hopper outlet nonclogging in the case of maximum blanking speed be: 0.035g/s.Suppose medicine simultaneously Agent granule is smooth spheroidal particle, makes C=0.64, k=1.5.Model is solved.

2. incorporating parametric is to model solution simulation optimization

According to parameter model solved and emulate, obtain putting in poison speed and frequency of vibration, relation such as Fig. 3 of amplitude, Shown in Fig. 4.It can be seen in figure 3 that along with the increase of frequency of vibration, prescribe medicine speed can be gradually increased, but be as frequency Increasing, there is saturated phenomenon, when frequency is about 3Hz, and it is the least on the impact of lower dose in prescribe medicine speed.Can from Fig. 4 To see, the increase of amplitude, it is also beneficial to improve prescribe medicine speed, but is as the increase of amplitude, prescribe medicine speed occurs saturated existing As, after amplitude is 20mm, the change of prescribe medicine speed is the least.

3., based on the relevant parameters optimization solved, contrived experiment checking is analyzed.

Being thered is provided vibration power source by cylinder, cylinder operation air pressure is 0.8Mpa.Material dissipates and is deposited in feed bin, dissipates bulk density It is 0.362g/ml.Material pipe is connected with feed bin.For the ease of observing blanking phenomenon, replace silver pipe with the glass tubing of same dimensions.

Test 1: lower dose is tested.Medicine storehouse chemical feeding quantity is 8 grams, carries out lower dose test, often group under different vibration conditions Under the conditions of the condition powder charge such as be repeated 5 times, calculate prescribe medicine, its experimental data is as shown in table 1.

1 time dose test of table

As it can be seen from table 1 condition 1 time, oscillation intensity is inadequate, and lower dose is few, changes over inconspicuous.Condition 4 times, Prescribe medicine speed is fast, lower dose skewness.Condition 2,3 times, prescribe medicine situation is good, but the lower dose concordance of condition 2 is preferable.

Test 2: lower dose Control experiment.Quality of material 15g, frequency is 3Hz, and amplitude is 20mm, and each time of vibration is 27 seconds, experiment was done 5 times, and result of the test is as shown in table 2.

2 times dose Control experiment tests of table

Analytical table 2 understands: when frequency of vibration is 3Hz, and amplitude is 20mm, and the average of lower dose is in target, and side Difference is less, controls effect preferable.Carrying out discharge quantity according to this parameter and control test, lower dose error is about 7%, and floating medicine Few.

By analyzing experimental result, can draw, before loading vibration, when medicament dissipates feed bin, have fragmentary material to fall, it Rear stopping；After loading vibration, medicament starts to fall.When frequency of vibration is 3Hz, and amplitude is 20mm, speed of putting in poison, control effect Fruit preferably, calculates with model and simulation result is identical.

Therefore, the model set up according to the present invention, based on the relevant parameters optimization solved, by change vibrosieve amplitude and Frequency, can effectively realize the stably feeding of slender type metal tube powder body medicament filling, and achieve and preferably load effect.

Finally illustrate, preferred embodiment above only in order to technical scheme to be described and unrestricted, although logical Cross above preferred embodiment the present invention to be described in detail, it is to be understood by those skilled in the art that can be In form and it is made various change, without departing from claims of the present invention limited range in details.

Claims (1)

1. the stably feeding model of a slender type metal tube powder body medicament filling, it is characterised in that: this model is described as follows:

$\left\{\begin{array}{c}Q={\mathrm{C\ρ}}_s\sqrt{g}{(D_0-{\mathrm{kd}}_p)}^{2.5}{\mathrm{ft}}_z\\ \mathrm{\π}{\left(r_{0}sin\mathrm{\θ}\right)}^2{\mathrm{\δ}}_c{\mathrm{\ρ}}_{s}g>4{\mathrm{mf}}^{2}L>f_c\end{array}\right.$

Wherein Q is lower dose；C and k is constant, relevant with internal friction angle, and its value can be through measuring；ρ_sPile up close for medicament Degree；G is acceleration of gravity；D₀For being administered mouth opening size；d_pParticle diameter for pharmacy particle；t_zRequired for cylinder moving distance L Time；F is the frequency of vibrosieve horizontal vibration；L is the amplitude of vibrosieve horizontal vibration；r₀For sieve aperture cross section inner circle radius；θ For inclination angle, sieve aperture cross section；δ_cFor micro unit height；M is the quality of horizontal vibration device；f_cFor open yield stress.

Further, this model is set up process and is had the following steps:

Step A: the micro unit mechanical analysis of medicament arch

Consider the micro unit that medicament as shown in Figure 1 encircles, take the micro unit containing the scope of freedom

Step A-1: solve the gravity of micro unit

Gravity (the W of micro unit_arch) can be approximately:

W_arch=π (r₀sinθ)²δ_cρ_sg

Step A-2: analyze applied external force F_w

Destroying arch, make pharmacy particle fall, the applied external force being applied to vibrosieve should be greater than open yield stress f_c, it may be assumed that

F_w＞ f_c

Step A-3: analyze frictional force F of micro unit and chamber wall_m

Micro unit should be less than micro unit gravity with the frictional force of chamber wall, it may be assumed that

F_m=μ F_w＜ W_arch

Wherein μ is the coefficient of friction of medicament and chamber wall

Step B: micro unit kinematics analysis

Step B-1: solve cylinder by the acceleration a of static divertical motion

A=8f²L

Step B-2: solve the maximal rate of cylinder moving

v₀=4fL

Step B-3: solve applied external force F being applied to vibrosieve_w

F_w=mv₀/ 2t=4mf²L

Step C: set up stably feeding model based on vibrosieve

Step C-1: medicament when cylinder bottom opening flows out, set mass flow empirical equation as:

$q_m={\mathrm{C\ρ}}_s\sqrt{g}{(D_0-{\mathrm{kd}}_p)}^{2.5}$

Step C-2: set up stably feeding model based on vibrosieve

$\left\{\begin{array}{c}Q={\mathrm{C\ρ}}_s\sqrt{g}{(D_0-{\mathrm{kd}}_p)}^{2.5}{\mathrm{ft}}_z\\ \mathrm{\π}{\left(r_{0}sin\mathrm{\θ}\right)}^2{\mathrm{\δ}}_c{\mathrm{\ρ}}_{s}g>4{\mathrm{mf}}^{2}L>f_c\end{array}\right.$