Product Specification
Specification
Item
Large Roller Press Grinding Rolls
Material
Die steel, alloy steel, stainless steel, etc.
Application
Roller Press
Packing
Seaworthy plywood packaged on stell pallets or as customers` request
Delivery date
Depends on the amount and dimension of products
Company Introduction
Luoyang Hong Xin Heavy Co., LTD. is located in Luoyang Xin'an Industrial Park, Luoyang Hongxin Heavy Machinery Co., Ltd is an enterprise featured with industrial designing, processing and manufacturing, which is qualified for import-export trade. Covering an area of 15,000 square meters and holding an annual production value of 80 million RMB, the company of 20 million RMB registered capital has total 100 staff members, among which there are 20 engineering technicians owning senior and medium professional titles and 40 intermediate and senior technicians capable of product designing and developing.
Hongxin is dedicated to produce reducers, hoists, crushers, Ball Grinding Mills and the equipments of screening, coal washing, metallurgy and cement, and replacement parts. Meanwhile, we provide the perform maintenance service for various series of equipments. There are 52 large-scale equipments applied into the manufacturing process, such as T200 CNC floor boring and milling machine, YK 73125 CNC molding gear grinding machine, YK322B CNC molding gear grinding machine, Y3200 gear hobbing machine, Y1600 CNC gear sharper, 4m vertical lathe, 6.3m CNC vertical lathe, T110 CNC boring machine, and 52 middle-sized productive and assistive equipments, which integrate strong manufacturing and processing capability with complete managing system of production and technology, quality management system and comprehensive testing measures.
Certificates
contacts
Roller Press Roller Press,Roller Briquette Press,Double Roller Press,Electric Roller Press Luoyang Hongxin Heavy Machinery CO., TLD. , https://www.hxreducer.com
Beneficiation plant materials used, not only many varieties, weighing frequently, and very poor working conditions, far from being leveraged mechanical scales can adapt. At present, electronic scales have been widely used in domestic and international concentrating plants. It is characterized by simple structure, convenient use and installation, fast response, high sensitivity, and long-distance signal, which is suitable for automatic detection and control.
The electronic scale converts the weight of the so-called material into an electrical signal through a load cell (also called "indenter") and then delivers it to the display or control meter. Load sensors have the following categories:
(1) using a piezoelectric sensor is certain crystals such as quartz, barium titanium, piezoelectric effect, etc., the weight converted to a current signal. Due to the limited force of the crystal, some crystals are easily damp or affected by humidity, so they are used as less indenters.
(2) pressure after the use of the magnetic sensor is subjected to a mechanical force ferromagnetic material, different pressures directivity generated, causing redistribution of the magnetic field lines, the induced potential occurring in the secondary winding of the respective twin reflecting load. Due to the increase in the output of cold-rolled silicon steel sheets, the piezomagnetic sensor has developed extremely fast and the application has become more and more extensive.
(3) The displacement sensor converts the weight change into a displacement by means of an elastic element, and then converts the displacement into electric quantity by using a capacitor, an inductor or a differential transformer. The capacity of this type of sensor is not large, and it is not widely used in industry.
(4) The strain resistance sensor is characterized by the fact that the resistance value of the strain gauge is changed with the load, and the weight is converted into an electrical signal. This is the most widely used one due to advances in electronic technology and semiconductor materials.
By applying any of the above sensors to form an appropriate detection circuit, the weight change can be converted into electricity to a secondary instrument or controller to form an electronic scale. There are two types of display instruments for electronic scales: one is analog with a variety of dynamic or automatic balancing instruments for early detection; the other is digital, indicating intuitive, high precision, and is now widely used.
Electronic scales can be divided into: hopper scales, belt scales, driving scales, railway scales and weighbridges, etc., but the application methods and structures are different, and the basic principle is the same.
In the concentrating plant, electronic scales are widely used for automatic weighing of ore. In recent years, electronic scales have developed rapidly and have many types. This chapter only introduces the basic working principle of common belt electronic scales, driving electronic scales and fixed-value electronic scales. .
First, the belt electronic scale
1. Working principle
The belt electronic scale is used to detect the delivery volume of solid bulk material, and it is convenient to automatically weigh the charge or ingredients. Figure 1 and Figure 2 are schematic block diagrams of the belt electronic scale. In the appropriate part of the middle of the belt, there is a frame dedicated to automatic weighing, the length L of this section is called the effective weighing section. The weight of the material on the L segment at a certain instant t is ΔW, which is transmitted to the sensor (indenter) through the weighing frame to cause deformation. The signal voltage ΔU 0 of the strain detection bridge output is proportional to ΔW, and the indenter structure is as As shown in Figure 3, the unit length of the effective length L is q t
Qt= â–³W/L
Figure 1 Â Belt electronic scale principle block diagram [next]
Figure 2 Â Â Belt scale principle ( Ste Fouray company information)
1. Sensor (scale); 2. Weighing roller; 3. Weighing component; 4. Flow; 5. Accumulation
Weight; 6. integrator; 7. power supply, single phase, 110V/220V50Hz; 8. integrator box;
9. Speed ​​measuring wheel; 10. Gearbox; 11. Speed ​​measuring generator; 12. Displacement transmitting device
Assuming that the belt moves at a speed of Ï… t , the instantaneous delivery of the belt is W t
W t =q t V t (1)
Because q t load material by strain gauges reflects, i.e., the amount of change of strain resistance variation ΔR / R of the linearly simulated q t. If the transmission speed υ t of the belt is linearly simulated by the power supply voltage U 1 of the strain bridge, the sensor detects the voltage signal ΔU 0 outputted by the bridge to simulate the instantaneous transmission amount of the belt W t
Figure 3 Â Indenter
1. strain gauge on the machine; 2. mechanical parts; 3. pressure; 4. indenter; 5. strain gauge R 1 ;
6. Temperature compensated strain gauge; 7. Strain gauge R 2 ; 8. Current detector
Therefore, it is necessary to measure the conveying speed of the belt, and automatically adjust the power supply voltage of the detecting bridge according to the conveying speed. Generally, the speed converter is driven by the belt friction roller, and the rotation speed n of the roller (proportional to the belt conveying speed) is converted into a frequency signal. Then, it is converted into a current I by the speed measuring unit to supply the bridge. Thus, the change in the bridge power supply voltage reflects the change in the belt transport speed. The voltage signal ΔU 0 outputted by the bridge (ie, the indenter) can reflect the instantaneous feed amount W t , and the voltage signal ΔU 0 is amplified by the amplification unit and output DC current I t =0~10 mA, which is sent to the instantaneous display. The instantaneous delivery of the belt. At the same time, the total amount of material conveyed by the belt during a certain period of time is accumulated by the integrated unit.
In 0~t time, the total amount of material conveyed by the belt is:
(2)[next]
Where C, K - the proportional constant.
In the integrated unit, the current signal I t representing the instantaneous delivery amount is converted into a frequency signal Æ’ t , and its integral with time is the number N of pulses in 0 to t, that is,
(3)
Therefore, the number of pulses N represents the total amount of material conveyed by the belt in 0~t time, and is sent to the electromagnetic counter for display.
The composition of the belt electronic scale includes two parts: a pressure head device and a secondary instrument (dashed box). The pressure head device is installed at the site, and the secondary instrument is composed of a speed measuring unit, an amplifying unit, an integrated calculating unit and a display recording device. Control room. The following is a brief description of the speed measuring unit and the integrated unit.
2. Speed ​​measuring unit
The task of the speed measuring unit is to convert the frequency signal sent by the speed converter into a direct current to supply the sensor bridge current. The speed converter is rotated by the frictional force of the roller moving along the belt, and drives the rotating wheel with the teeth. When the convex portion of the tooth is aligned with the fixed permanent magnet, the magnetic flux of the magnetic circuit is the largest; the concave of the gear When the magnetic pole is aligned, the magnetic flux is minimal. This pulsating change of the magnetic flux induces a frequency signal Æ’ on the coil. Obviously, the frequency Æ’ is determined by the moving speed of the belt Ï… t , ie
Vt
Æ’=A----------,Hz
лD
(4)
Where A—the number of equal teeth of the rotating wheel (the instrument is designed to be 30 or 60 teeth)
D—The diameter of the friction roller (instrument design is 0.1 m).
When the belt speed is less than 0.5 m / s, directly drive the shaft of the speed converter, the output frequency is
n
ƒ ′=A-------, Hz
60
(5)
Where n is the speed of the speed converter shaft, r / min.
According to the above two formulas, the output frequency signal of the converter is 100~400 Hz at the maximum speed of the belt.
The principle circuit of the speed measuring unit is shown in Figure 4. The frequency signal sent by the speed converter is bidirectionally limited by D 1 and D 2 and then enters the BG 1 preamplifier, which is converted into a rectangular pulse by the BG 2 and BG 3 pulse shaping circuits. The differential circuit composed of R 13 and C 5 is converted into a positive and negative spike, and the negative pulse enters the BG 4 and BG 5 bistable triggers, so that BG 5 is turned on, and BG 4 and BG 6 are turned off. At this time, the DC regulated power supply (30 volts) charges the capacitors C 6~8 , and the charging current passes through R 26 . When the charging voltage of C 6~8 reaches the breakdown voltage of the Zener diodes DW 1 and DW 2 , the voltage charged on it is fed back to the base of the BG 4 , so that the bistable flip-flop is reversed and restored, that is, BG 4 and BG 6 is turned on and BG 5 is turned off. At this time, the charge on C 6~8 discharges BG 6 , and the discharge current does not pass through R 26 . Seen, when there is a frequency signal is input pre-amplifier, the R 26 have the pulsating DC voltage. The higher the frequency of the input, the more the number of discharges per unit time, the higher the pulsating DC voltage on R 26. The pulsating voltage is sent to the modulated DC amplifier composed of BG 7 and BG 8 through the double L-shaped filter, and the amplified signal is sent to the BG 9 , BG 10 and D 8 phase sensitive power amplifiers after being amplified by the output transformer T 1 . A DC current of about 42 mA is obtained, and the power supply from the strain sensing bridge is supplied from the terminal 7, and a DC voltage of about 10 volts is obtained on the sensor (when the total resistance of the bridge is 240 ohms). As seen from the above, the power supply voltage as the strain detecting bridge is varied with the belt moving speed, that is, it simulates the belt moving speed.
In the figure, the potentiometer W 1 is used to adjust the lower limit value of the bridge voltage; the potentiometer W m is used to adjust the upper limit value of the bridge voltage. When inputting different values ​​between the highest frequency between 100 and 400, the value of the speed regulating capacitor C 6~8 is required to satisfy the voltage drop of nearly 1 volt on R 25 , which can be checked by the jack L c . [next]
Figure 4 principle circuit of speed measuring unit
Figure 5 integrated unit principle circuit
3. Integral unit
Converting the 0~10 mA DC current I t of the amplifier output into a pulse signal Æ’ tl to be sent to the electromagnetic counter to count, and accumulating the number of pulses N, showing the total amount of material conveyed by the belt after a certain period of time, is the unit The work to be done. The principle of the integrated unit is shown in Figure 5. The DC current signal from the amplifier is applied to D 1 and R 2 to form a DC signal voltage. BG 1 is a current converter. As the DC signal voltage rises and falls, the converted micro-ampere current source charges capacitor C 2 when its charging voltage rises to make the base voltage of BG 2 be higher than its emitter. when the voltage is positive, since the AC 100T winding of the transformer T in a positive feedback, so that BG 2 immediately turned on, the rapid formation of oscillations in the secondary of the transformer T is a step to produce a negative pulse, the R 13 and C 3 After differentiation, a negative spike is formed. After D 7 to the base of BG 4 , the BG 3 and BG 4 monostable circuits are turned over, that is, BG 1 is turned off and BG 3 is turned on. At this time, the charge on C 2 passes through R 11 . BG 3 is discharged, and at the same time, BG 2 is also turned off to stop the oscillation. This state is unstable, to maintain the time determined in (R 17 + R 18) C 4 of the product, after which time the one-shot to be turned over, i.e., BG 3 off, BG 4 is turned on, this is the first a process. At this point capacitor C 2 starts charging again and begins the second process. By repeating this cycle, BG 1 obtains a pulse frequency signal converted from a DC current signal from the amplifier. Obviously, when the input current increases, the number of times of charging and discharging of the capacitor C 2 per unit time is large, and the pulse frequency obtained at the collector of the BG 4 is high, and the opposite is low, thereby completing the task of current/frequency conversion.
The pulse signal obtained by BG 4 must also be amplified in order to push the electromagnetic counter. After the pulse signal is limited by DW 4 , it is sent to BG 7 and BG 8 for power amplification, and the amplified current is led to the electromagnetic counter J s by the collector, and the pulse number is accumulated.
The amount of material conveyed by the belt is large or small. In order to register the cumulative speed of the counter, the different connections of R 5 ~ R 8 can be used, and the resistance value of W 2 is adjusted so that the output of the amplifier is 10 amps, which is just the belt. The instantaneous maximum delivery amount, as the lower limit of the delivery amount is pre-applied to the base loop of BG 1 by the voltage on W 1 , increases the initial dead zone of BG 1 to improve the linearity of the lower limit of the range.
In order to avoid the cumulative error caused by the belt running, when the output current of the amplifier is less than 1 mA, the voltage drop on R 1 is lower, compared with the voltage pre-applied on W 4 and D 4 to make BG 5 When the base potential is extremely positive compared to the emission, the oscillation circuit composed of BG 5 is in an oscillating state. On the one hand, the oscillating current is sent to BG 6 after D 10 detection, so that BG 6 is turned on, the weighing pulse signal from the BG 4 collector is short-circuited, and the counter J s can not get the counting pulse, so the counting is stopped and avoided. On the other hand, the eddy current is sent to the power amplifiers BG 9 and BG 10 after being detected by D 11 , so that the signal indicator Z 2 is lit. When there is material on the belt and the output current of the amplifier is greater than 1 At mA, if the voltage drop of R 1 is compared with the voltage at W 4 and D 9 , the base potential of BG 5 can be made close to zero or the emitter is extremely negative, then the self-excited oscillator BG 5 stops. Oscillation, BG 6 cutoff, the weighing pulse signal from BG 4 smoothly leads to the electromagnetic counter, accumulating the total amount of material conveyed by the belt. At this time, the signal indicator Z 2 is turned off.