Feeder parameter selection and calculation

Parameter Choice of Vibrating Feeder
Abstract: Replacing heavy duty apron feeders, vibrating feeders that can handle coarse ore are more and more popular in mine. The paper introduces the parameter choice using ZG1642 vibrating feeder.
Keywords: vibrating feeder, design parameter

Pick   To: The feeder can transport bulk materials gradually replaced heavy plate feeder, more and more widely. In this paper, ZG1642 feeder, for example, the feeder selection and calculation of parameters were introduced.
Keywords:   Feeder, parameter calculation 
Storage material in the size of> 500mm in the lower bin, usually installed heavy-duty apron feeder, as the beginning of a continuous and uniform feeding broken equipment. Heavy plate feeder is the traditional delivery system, an important ore equipment, especially for conveying large proportion of large size, wear resistance materials, and in the open air, moisture and other work reliably under adverse conditions, so in metallurgical and mining, cement, building materials widely used in other departments. The machine can be installed horizontally, can also be tilted installation, maximum installation angle of 25 º. It can withstand the ore bin in the materials it generated enormous pressure, and when the bulk material into the ore bin enormous impact. 
Heavy plate feeder Despite these advantages, but there are also purchase high cost, complex structure, such as lack of maintenance and overhaul workload. In particular, need to drive power consumption and more large and wearing parts, so its operating costs. In the energy and resources are becoming scarce today, with the vibration motor as vibration source of feeder used more and more. And heavy-duty apron feeder compared to saving energy, the structure more simple, smaller form factor.
Hebi Thermodynamic Instrumentation Factory, Novi developed ZG Series Vibrating Feeder as parameters and structure design, equipment reliability, the mine has been more widely used. In this paper, ZG1642 feeder, for example, the feeder selection and calculation of parameters for an introduction.
1. ZG1642 feeder structure
Shown in Figure 1, ZG1642 feeder by the vibration motor, vibration slots, support springs, chassis and other components.Source of the vibration motor is vibrating, it produces exciting force, is to produce vibration force vibration trough power components. The unit uses two vibrating motor as vibration source, the two reverse self-synchronous motor for rotation, the eccentric block to adjust the motor excitation force can be adjusted to achieve. Excitation frequency is the frequency feeder.Exciting force directly affects the size of the amplitude of equipment, equipment reliability depends largely on the excitation device.
Slot is the material of the bearing vibration components to withstand high-frequency alternating load, all of the body are the reference oscillator plasmid, it must have sufficient stiffness and strength. Vibration welded steel tank by the use of exposure in the form. Vibration 16mm bottom and 20mm from the bottom liner composition. Two vibration motor vibrating trough placed in the lower symmetry, for the simultaneous reverse operation, the exciting force produced by vibration of the motor axis perpendicular to the two lines formed by the plane, the tank produces a straight line along the direction of the vibration exciting force.
Bearing vibration spring is elastic support system slot. Conveyor according to the working state, choose the support spring.ZG1642 energy efficient feeder work in the ultra-resonance state, the spring should be selected and softer, so that the natural frequency away from the operating frequency. Metal springs and rubber springs in the machine are applied. Compared with metal springs, rubber springs can withstand compression and shear deformation; internal friction damping is much greater than metal springs, the working noise. 

Figure 1 ZG1642 energy efficient feeder structure
1 - frame; 2-- vibration slots; 3 - vibration motor; 4-- bearing spring 
2. ZG1642 feeder design ideas
2.1 Design Goals
(1) Feed size> 750mm;
(2) production capacity of 150-340m 3 / h;
(3) Reliability with comparable heavy-duty apron feeder, feeding a continuous, uniform;
(4) energy, less wearing parts, low operating costs. 
2.2 Technical difficulties
(1) equipment installed in the bottom of the ore hopper, conveyor tank tops bear the enormous pressure from the upper part of the ore. Equipment in this state by force, must also complete the short distance transport and continuous, even feeding.
(2) to overcome the precarious situation of vibration, to ensure equipment reliability, reduce noise and spread to the foundation of the dynamic load.
2.3 Key Design
(1) ultra-resonance frequency, vibration tank to ensure sufficient strength and stiffness.
(2) application of IF, in pieces large angle technology to ensure the equipment can be reliably transported 750mm of lump ores.
3 Design Sourcebook
(1) the nature of materials: ore after blasting, the maximum feed size 750mm;
(2) Capacity :150-340m 3 / h;
(3) work systems: continuous;
(4) Venue: open or underground mine;
(5) process requirements: a continuous and uniform feeding function.
4. The principle of selection of parameters 
ZG1642 energy efficient feeder of the basic parameters can be divided into kinematics (or operating parameters) and the kinetic parameters (or structural parameters) in two parts. Kinematic parameters, including mechanical index, throwing index, vibration frequency, amplitude, vibration direction angle, dip tank and the materials the average speed. Kinetic parameters of the exciting ways, including equipment, centrifugal force, vibration quality parameters, the system's natural frequency and spring stiffness. 
Feeder in the design, first consider how to select a reasonable amplitude, frequency and vibration direction of the angle to calculate transmission speed. Then throughput requirements, design a carrying device section. Then the required amplitude, frequency and vibration direction of the angle, the vibration screening to determine the structural parameters of the feeder.Structure and determine the choice of structural parameters, should consider ways to reduce power consumption, and equipment to work the basis of stability and power balance or vibration problems. 
Parameter selection principles:
(1) taking into account the mechanical strength of materials, design, mechanical index should be used generally K <6.
(2) throw index D determines the size of campaign materials or non-periodic cyclical throwing throwing motion. Currently most used periodically throwing motion, that is, D = 1 ~ 3.3, the face of the acceleration to meet: 

(3) to improve transport efficiency, the use of throwing sport, choose the larger the amplitude A and a lower frequency f.However, delivery of materials large size, easy to produce impact noise, the material down to lower tank with the relative impact velocity, to use a higher frequency f and a smaller amplitude A. 
5. Kinematics selection and calculation
5.1 mechanical index K 
Mechanical index, also known as the vibration strength is the material in the direction of the exciting force and the acceleration of gravity on the ratio of maximum acceleration, calculated as follows: 
 
Where K-mechanical index; 
f-frequency, s -1; 
A-amplitude, m; 
g-acceleration due to gravity, 9.81m / s 2; 
For the throwing motion of the material feeder to do, to make materials to achieve more good throwing motion and a larger delivery rate, as well as strengthening the feeder in the subdivision, but part strength and stiffness of the case, make the machine more long-lasting work, the choice of mechanical index is usually, K = 2 ~ 5. K value is too low, the material does not throw up, amplitude instability. K value is too high, the tank body stiffness and strength, the case will affect the work, and cause premature damage to the tank. For powder materials, wet materials, K should take large values. For the bulk material, K should take a small value. Designed to take the mechanical index K = 3.6.
Throw index D 5.2 
Throw index D is throwing motion characteristics of the material is the maximum value of vibration acceleration at the bottom of normal weight and normal acceleration of gravity at the bottom of the weight ratio: 
 
Where:  - Vibration direction angle; 
 - Dip tank 
D = 1, the throwing motion is the critical point; 
D <1, the sliding movement of materials to do; 
D> 1, the materials do throwing motion. 
Design, often taking 1 <D <3.3, the significance of the material is tossed tank flying time is less than the vibration cycle.The design take D = 3.2.
5.3 vibration frequency f and amplitude A 
Mechanical index K is determined, according to the nature of the material, in accordance with the following formula to determine the frequency and amplitude. 
 
Vibrating conveyor, commonly used in the amplitude of frequency, because the amplitude is too large, need to increase the quality of the exciter and eccentric block increases starting torque, high frequency will increase the bearing pressure and the dynamic mechanical stress and dynamic deformation. It usually take A = 0.5 ~ 5mm, f = 16 ~ 30Hz. 
Under normal circumstances, when the mechanical index are the same, large-amplitude low-frequency small-amplitude high-frequency than the higher transmission speeds, therefore, advantageous to reduce the frequency of delivery. To avoid the transmission slot to affect the elastic bending normal delivery and accelerated material damage to tank, you should pay attention to the elastic bending of the conveyor trough of the first order natural frequency is 1.4 times higher than the operating frequency or frequency range for two-stage natural frequency of the middle. Tilt in the transportation and bulk materials transportation, the amplitude should take a small value. 
The design take A = 3.5mm, the frequency f = 16Hz.
5.4 dip tank  
Dip tank for the tank bottom and the horizontal angle. This design uses a small vibration frequency and amplitude, in order to increase the transmission speed, increase transmission capacity, tank installation select downwards. But the angle is not too large, otherwise the friction material and the tank increased, the installation of the machine increases with height. The design selected dip tank  = 15 °.
5.5 Vibration direction angle  
Vibration direction of the angle of the direction of the exciting force and tank bottom plane angle. Reasonable choice of vibration direction angle can improve the transmission efficiency. Direction angle and mechanical vibration index K and the material characteristics. Affect  Value of the selected factors are material particle size, moisture, material thickness and noise requirements. The greater the material thickness,  Take large values. 
While in theory you can find a mechanical index K with the rate corresponding to maximum vibration direction angle, direction angle is the best vibration  . But in fact, the common point within the transmission speed of change is not obvious. It is generally the best vibration vibration conveyor direction angle  Can be selected within a certain range. 
When K = 3-5, the  = 28 ~ 38 °; 
When K = 5-7, the  = 20 ~ 30 °. 
In this design, taking into account the vibration frequency f and amplitude A to select a small value, and dip tank Increased, so select the vibration direction angle  = 60 °.
5.6 The average transport velocity v material 
The average material velocity v and the material transport properties, material thickness, the vibration frequency f, amplitude A, the vibration direction angle  And tank installation angle  On the following formula, 
 
Where v-transfer of materials, the average speed of m / s; 
f-frequency s -1; 
 - Dip tank  ; 
 - Direction angle  ; 
g-acceleration due to gravity m / s 2; 
 - Speed ​​correction factor for the large, dry material, 0.85 ~ 1.0 
 - Throw factor that material time and flight vibration period of the tank 
Ratio, usually take 0.77 to 0.84. 
6 Kinetic parameters calculation
6.1 Quality parameters calculated vibration 
 
Where  - Transport tank (including the exciter) quality, 1500kg; 
 - A combination of tank material quality, 
 , 
 Combination coefficient for the material, 0.1 to 0.2, 
 Quality materials for the tank.
6.2 system natural frequency 
 
Where w-system frequency 
Z-tuning value, taking 4 to 5.
6.3 supporting spring stiffness 

6.4 Centrifugal force 

6.5 Motor Power 
 
Where: N 1 vibration power consumption 
N 2 bearing friction power consumption 
 Transmission efficiency, taking 0.98 
 
Where G is the damping coefficient, take 0.3 
 
Where e is the bearing friction coefficient (taking into account tilt setting motor, motor bearings subject to axial force), taking 0.008; 
d motor shaft, taking 0.08m. 

Then 
7 Structural design and calculation of process parameters
7.1 Vibration slot structure 
In order to reduce the inertia force, to ensure the strength and stiffness under the premise should be to minimize the vibration of the quality of tank. In this design, the vibration trough bottom with 16mm thick steel plate welded together, then ribs strengthened. Vibration using 20mm thick steel tank lining. Vibration used in all killed steel tank material, able to work due to vibration generated by the process of alternating load, easy to weld cracking. 
Tank width should satisfy the condition  
Where k 1 - coefficient of not screening the material, usually take 2 to 3; 
dmax-largest particle size, 750mm. 
Designed to take the tank width B = 1600mm.
7.2 Vibration Motor Selection 
Based on the above calculation, select the two vibrating motors, electrical power is 5.5kW, motor speed 960r/min, the vibrating force by changing the angle of the eccentric block to adjust. Vibration Motor Model YZS-75-6B, the largest single motor excitation force is 75000N.
7.3 Flexible component design 
Rubber spring has the following characteristics: (1) rubber modulus is much smaller than the metal, the hardness changes in the larger context of change; (2) rubber spring can withstand compression and shear deformation; (3) internal friction damping is much greater than metal springs, the working noise. 
Based on the above characteristics, the elastic element in the design of the feeder, we have chosen four YB35-180-360 rubber spring. The pressure area AL = 471cm 2 area AF = 1131cm3 deformed shape factor S = 0.417, shape ratio = 1.54. 
Rubber spring parameters in Table 1

Production capacity of 7.4 calculated 
 
Where h is the thickness of the material, select 400mm. 
8 Technical performance
The main technical parameters of this device are as follows:
(1) Production capacity :150-340m 3 / h;
(2) Maximum exciting force: 2 x 75kN;
(3) Vibration frequency: 960 beats / min;
(4) Amplitude: 3.5mm;
(5) Vibration Motor power: 2 x 5.5 kW;
(6) vibration slot length: 4200mm;
(7) vibration width: 1600mm;
(8) vibration-slot angle: 15 °;
(9) vibration direction angle: 60 °;
(10) The maximum feed block degree: 750mm;
(11) screening size: 100mm;
(12) Dimensions (L x W x H): 4057 x 2100 x 1730mm;
(13) Weight: 3045kg
9 Conclusion
ZG Series Vibrating Feeder energy efficient structural parameters, kinematics and kinetic parameters designed, super-resonance in the work area to ensure equipment reliability. Adequate transport tank stiffness and strength, not open to ensure the frame body welding, no deformation. Equipment is reliable, simple structure, lower acquisition costs and operating costs, dramatically reducing the amount of infrastructure construction, to mine large size, high capacity, energy saving, easy operation and maintenance. Currently the series has been the second phase in Xinxin Mining Company, Xingtai, Hebei Lihua iron ore, Jinchuan's three mines, Western Mining and Luan River molybdenum mining industry and other application. The product can be widely used in China's metallurgical and mining, chemical industry, mining and building materials to replace the traditional heavy-duty apron feeder, has a very broad application prospects. 
References:

1. "Mechanized transport Design Manual", Machinery Industry Press, Zhang Zhi-yi, 1997.04;
2. "Vibration to the material screening unit development and industrial applications", metal mines, Daixing Guo et al, 1997 No. 1;
3. "Bottom feeder warehouse design research", Logistics Technology and Application, feeder design research positions at the end of 1999, Volume 4 No. 3;
4. "Feeder isolation system theory and design", China Mining Engineering, Wang, August 2004;
5. "Development and Prospects of mechanical vibration," Mining Letters, Fan Chaoyang, February 2004 No. 2;
6. "How to Design Efficient and Reliable Feeders for Bulk Solids", JENIKE & JOHANSON INCORPORATED, John W. Carson.

Parameter Choice of Vibrating Feeder
Abstract: Replacing heavy duty apron feeders, vibrating feeders that can handle coarse ore are more and more popular in mine. The paper introduces the parameter choice using ZG1642 vibrating feeder.
Keywords: vibrating feeder, design parameter