SE523037C2 - Methods and apparatus for crushing plant - Google Patents

Abstract

A crushing plant (1) has a crusher (9) and a drive unit (2) which drives the crusher (9). The drive unit (2) is arranged to drive a coupling (5), which transmits power to the crusher (9) via an output shaft (6) from the coupling (5). The crushing plant (1) also has a measuring device (12, 14, 16) which is arranged to deternine the torque which the output shaft (6) transmits to the crusher (9). The operation of the crushing plant (1) is monitored by the determination of this torque, with the help of the measuring device (12, 14, 16).

Description

o o oooo o oo o oc; oo oooo oo o oo o o ono o n ooo ooo ooo ooo 10 15 20 25 30 35 s2z etc: ß $ æß¿:; .. ¿«:; i fl 2 do not obtain the necessary information to be able to control the crusher.

US 5,803,376 describes a method of controlling a mobile crusher. The crusher is driven by a hydraulic motor whose hydraulic fluid pressure and flow are measured. The measured values can then give a measure of the power that the hydraulic motor develops. It is also proposed to measure the speed of a shaft emanating from the hydraulic motor. This method has the disadvantage that measurement of load on the crusher is not possible if the engine is of a type other than hydraulic or if the hydraulic motor also drives another component in addition to the crusher.

US 5,833,150 describes a method of controlling a mobile crusher driven by a hydraulic pump. The hydraulic pump pumps hydraulic fluid to a number of hydraulic motors, one of which drives the crusher, one drives an input system, one drives an output system, and so on. A speedometer measures the speed of the crusher and sends a signal to a control system. However, the speed of the crusher provides unreliable information about the load on the crusher. The speed of the crusher will thus vary at the start and stop of the crusher and at oscillations in the function of the hydraulic motor driving the crusher without this being due to varying loads on the crusher.

SUMMARY OF THE INVENTION The object of the present invention is therefore to provide a crushing plant in which a drive source of any kind can be used and which has a device for reliable measurement of the load on a crusher regardless of the type of drive source used.

This object is achieved by means of a crushing plant, which comprises a crushing drive and a crushing drive drive source and is characterized in that the drive source is arranged to drive a coupling, which transmits power to the crusher via a shaft extending from the coupling, and that the crushing plant has a measuring device, which is arranged to determine the torque which the output shaft transmits to the crusher. By determining the torque after the clutch, it is possible to arrange an optional drive source before the clutch and still determine a reliable value of the torque. This means that the crushing plant can easily be adapted to changing conditions in terms of, for example, access to different fuels. The drive source can also drive additional devices via a gearbox located between the drive source and the clutch, whereby it is still possible to determine the force transmitted to the crusher itself.

Preferably, the drive source has been selected from a group consisting of explosion motors and hydraulic motors. Explosion motors have the advantage that they are independent of an electrical network. It is thus possible to use the crushing plant in places where there is no access to electric current. Particularly preferred is that the propellant is a propellant diesel engine. Diesel engines have several advantages; is relatively cheap and easy to handle and the engines are robust and give a high torque even at relatively low, constant speeds.

The coupling is preferably a hydraulic slip coupling. A major advantage of hydraulic slip couplings is that they slip if the crusher gets stuck, ie that the shaft included in the coupling can rotate even though the crusher and the output shaft are stationary. In this way, it is avoided that transmissions and drive sources are exposed to high stresses and damage. Even when starting and stopping the crusher, it is an advantage that the slip clutch can slip. The hydraulic fluid flow to the coupling can, for example, be temporarily switched off, whereby the drive source can be rotated up to full speed before the crusher is allowed to wind up at a leisurely pace. Even during normal operation, the slip clutch has great advantages in that transmission shocks and vibrations in the drive source are not transmitted to the crusher. In the same way, vibrations will not be transmitted from the crusher to the gearbox and drive source.

According to a preferred embodiment, the measuring device is arranged to measure a first 10 by means of a first measuring unit; on nn oa nu n 0 I u ou -n n. n u. nu un n ... n .u a. .n n. .- nua »- -.- .uu 1 ~ - .. u. uv u ... 1 n n »n ..- ~ n n ~. . . g nu -0 u - ~. u. 4 speeds, which is representative of an axis included in the coupling, and to measure by means of a second measuring unit a second speed, which is representative of the output shaft. In the case of slip clutches, the shaft entering the clutch and the shaft leaving the slip clutch will rotate at slightly different speeds. The difference in speed depends, under otherwise constant conditions, on the load that at the relevant time affects the crusher. The greater the difference in speed, the more power is transferred to the crusher. Measurement units for speed measurement are inexpensive and provide very reliable measurement data.

According to a preferred embodiment, the slip clutch has a first vane and a second vane, which vanes are separated from each other by means of a gap, the first measuring unit being arranged to measure the speed of the first vane and the second measuring unit being arranged to measure the second blade speed. Slip couplings usually include at least two blades, which are also called impellers, wheels, rotors etc. During operation, the housing of the slip clutch and also the gap between the blades contain hydraulic fluid. The viscosity of the hydraulic fluid and the gap means that the first paddle, which is driven by the drive source, tends to pull the second paddle with it. By directly measuring the respective speeds of the blades, you can easily calculate a ratio between the speeds without having to take into account downs and gears in transmissions.

The crushing plant suitably has a calculation device, which is arranged on the basis of the measured speeds and a calibration curve for the clutch to determine the torque which the output shaft transmits to the crusher. With the help of the calibration curve, the calculation device can calculate a value of the torque based on the speeds. The calibration curve is specific to a certain coupling with a certain hydraulic fluid and makes it possible to obtain a very reliable value at the current torque. The calculation device can also measure very rapid changes in load 15 15 25 25 25 35 f523 037 5 which means that errors can be corrected quickly and damage can be avoided.

According to a preferred embodiment, a display device is arranged to display at least one value which is included in a group of values consisting of the determined torque, a power calculated from the determined torque, a measured first speed and a measured second speed.

Display of the above values gives an operator information about the conditions in the crusher. The operator can then set the crusher so that the largest possible production of crushed material is obtained within the limits set for the above-mentioned values. The operator can also detect faults in the crushing plant and the parts that feed material, and he also gets an indication when the fed material changes character in terms of, for example, hardness and size.

The crusher can be a gyratory crusher, a jaw crusher, a roller crusher or a percussion crusher. All these types of crushers are driven by a drive source and are exposed to different loads depending on the hardness, quantity, size etc. of the fed material. By determining the load, the operation of the crusher can be improved in terms of the size of crushed material and the amount of material crushed per unit time, and damage can be avoided.

Preferably, the crushing plant has a control system, which is intended to control the operation of the crusher in dependence on the determined torque. With the help of a reliable value of the torque, the control system makes it possible to obtain the largest possible production of crushed material with as even a size distribution as possible without manual monitoring. The control can, for example, include the following parameters: The feed speed of the material, size of feed material from a previous crushing, the speed of the crusher, the setting of the crusher etc. The control system can also be given alarm and emergency stop functions to avoid damage to personnel and equipment. 10 15 20 25 30 35 5 2 3 0 3 7 Éïï * - z 6 According to a preferred embodiment, the crusher is a gyratory crusher, the control system being arranged to, depending on the determined torque and signals from pressure and position sensors, which are arranged on the gyratory crusher, control the crossover width of the gyratory crusher. The crush gap width is a critical parameter in the operation of gyratory crushers. If the crushing gap width is too large, the size of the crushed material increases and if the crushing gap width is too small, the production of crushed material decreases at the same time as the crusher becomes heavier and risks getting stuck.

The position sensor measures the position of the crusher shaft of the crusher and thus indirectly the width of the crusher, and the pressure gauge measures which pressure in the vertical direction affects the crusher shaft of the crusher, to prevent the crusher shaft from getting the wrong position in relation to the crusher's fixed outer shell. With the help of the determined torque, the control system can adjust the crushing gap width so that the crusher provides the greatest possible production of crushed material, whereby the crushing gap width is controlled within certain specified limits.

According to a preferred embodiment, the crushing plant is a mobile crushing plant. In the case of mobile crushing plants, it is sometimes interesting to connect an external drive source to the coupling which is of an arbitrary type and which is located at the place where the crushing plant was transported. It is common for mobile crushing plants to be equipped with diesel engines due to a lack of access to electric power at the workplace in question. These diesel engines often also drive other power consumers via a gearbox arranged before the clutch. The object of the present invention is also to provide a method for monitoring the operation of a crushing plant, which method is applicable to any type of drive source and provides a reliable measurement of the load on the crusher regardless of the type of drive source used. This object is achieved by means of a method of monitoring the operation of a crushing plant, which comprises a crushing and a crushing driving source, which method is characterized in that a coupling is driven by the driving source, that the crushing is driven by a shaft extending from the coupling and that the torque which the output shaft transmits to the crusher is determined by means of a measuring device. As mentioned above, there are several advantages to choosing an arbitrary power source.

Preferably, the clutch is a hydraulic slip clutch and the drive source is a diesel engine, a first speed, which is representative of an axis input to the clutch, and a second speed, which is representative of the output shaft, being measured. Crusher systems that have hydraulic slip couplings driven by diesel engines are robust by several bowls. On the one hand, diesel engines are reliable and not dependent on electric current, but use a relatively easy-to-handle fuel, and on the other hand, hydraulic slip couplings facilitate start-up and stop procedures and reduce the risk of damage to the engine, transmission, personnel, etc. Speed measurement can be done with high precision and reliability.

The torque transmitted from the output shaft to the crusher is suitably determined by means of a calculation device based on the measured speeds and a calibration curve for the clutch. The fixing can be performed with high precision and in real time and allows the operation of the crusher to be optimized to a very high amount of crushed material per unit of time within the limits of the size of the crushed material.

According to a particularly preferred embodiment, the crusher is a gyratory crusher, wherein a control system is used to control the crushing gap width of the gyratory crusher arranged with the aid of the determined torque and signals from pressure and position sensors arranged on the crusher. As mentioned above, control of the crushing gap width makes it possible to optimize the operation of a gyratory crusher. Brief description of the drawings The invention will in the following be described in more detail with the aid of an exemplary embodiment and with reference to the accompanying drawings. .

Fig. 1 schematically shows a crushing plant according to the invention.

Fig. 2 shows a gyratory crusher included in the crushing plant.

Fig. 3 schematically shows a hydraulic slip clutch included in the crushing plant.

Fig. 4 shows a measuring device mounted on the slip coupling in Fig. 3.

Fig. 5 shows a calibration curve for the slip clutch.

Description of preferred embodiments Fig. 1 shows a crushing plant 1. The crushing plant 1 has a drive source 2 in the form of a diesel engine. The diesel engine 2 drives via a drive shaft 3, which extends through a gearbox 4, a hydraulic slip clutch 5. The gearbox 4 is arranged to distribute power from the drive shaft 3 to a number of components (not shown) at the crushing plant 1.

The drive shaft 3 constitutes the input shaft of the slip clutch 5. The slip clutch 5 also has an output shaft 6, which via a transmission 7 and a shaft 8 drives a gyratory crusher 9. The crusher 9 is fed with material from a feeding device 10, which feeds material to a crusher pocket 11 located on top of the crusher 9. .

A first speed V1, which is representative of the shaft 3 included in the slip clutch 5, is measured by an inductive first sensor 12. In the embodiment shown in Fig. 1, the first sensor 12 is arranged to measure the speed of a the slip clutch 5 included first paddle 13. Second speeds, which are representative of the input shaft 3, can also be measured. As shown in Fig. 1, a sensor can alternatively be placed in one of a plurality of different positions 12 '.

A second speed V2, which is representative of the shaft 6 emanating from the slip clutch 5, is measured by an inductive second sensor 14. In the embodiment shown in Fig. 1, the second sensor is 14 arranged to measure the speed of a second vane 15 included in the slip clutch 5.

Other speeds, which are representative of the output shaft 6, can also be measured. As shown in Fig. 1, a sensor can alternatively be placed in one of a plurality of different positions 14 '.

The signals from the first sensor 12 and the second sensor 14 are received by a calculation device 16. The calculation device 16 uses a calibration curve K which applies to the slip clutch 5 with the current hydraulic oil. With the aid of the speeds V1 and V2 and the curve K, the calculation device 16 can calculate the torque M which is currently transmitted to the crusher 9 by the slip clutch 5.

The gyratory crusher 9 has a pressure sensor 17 and a position sensor 18, which are shown schematically in Fig. 2. Signals 17 ', 18' from the sensors 17, 18 are processed in a collecting device 19.

The feed rate of the feed device 10 is controlled by a feed control system 20. The crush pocket 11 is provided with a high level sensor 21 and a low level sensor 22. Depending on these level sensors 21, 22, the feed control system 20 controls the amount of material fed by the feed device 10.

A control system 23 receives signals partly from the computing device 16 and partly from the collection device 19.

The control system 23 converts the determined torque M to an effect E which is shown on a display or a display device 23 '. The control system 23 also sends a control signal to a control means 24. The control means 24 adjusts the crushing gap width S (Fig. 2) selected by the control system 23 with regard to the determined torque M, the position of the crushing shaft 25 of the crusher 9 and its pressure.

Fig. 2 shows a gyratory crusher 9 according to known technology. The crusher shaft 25, which is eccentrically mounted at its lower end 26, is provided with an inner jacket 27, which at the simultaneous rotational and oscillating movement of the crusher shaft 25 crushes material which has been fed in at the crusher 910 l5 20 25 30 35 525 037 Upper part 28, against an outer jacket 29. Between the inner jacket 27 and the outer jacket 29 a crushing gap 30 is formed. As the crushing shaft 25 of the control member 24 is moved in vertical direction, the crushing gap width S of the crushing gap 30 will change, whereby the ratio between the amount of material of the crusher 9 and the size of the material can be set. If the moment M calculated by the calculating device 16 for some reason increases above a preselected value, for example due to unusually hard material entering the crusher, the control system 23 via the control device 24 temporarily increases the crushing gap width S of the crusher 9 by 25 is moved down. Thus, more material, and also any unbreakable objects, can pass through the crusher 9, which causes the moment M to drop.

Fig. 3 shows in cross section the hydraulic slip coupling 5. The drive shaft 3 is fixedly connected to a flange 31, which in turn is fixedly connected to the first vane 13, and can thus rotate the first vane 13. Hydraulic fluid is passed under operation continuously into the slip clutch 5 via an inlet I. The hydraulic fluid is then led between the first vane 13 and the second vane 15, which is substantially enclosed by the first vane 13, and passes out through narrow gaps 32 between the vanes 13, 15 and drainage holes 32 'in these. The vanes 13, 15 thus have no contact with each other, but the force is transferred from the first vane 13 to the second vane 15 by means of the viscosity of the hydraulic fluid. The coupling 5 has a housing 33, which collects the hydraulic fluid and carries it to a tank 33 'located at the bottom of the housing 33. From the tank 33 'the hydraulic fluid is then drained from the coupling 5 through a drain line U. The hydraulic fluid is then pumped by a pump 34, driven by the diesel engine 2, to a cooling circuit (not shown) to be subjected to a temperature controlled cooling before being returned to the coupling 5 inlet I.

When no power transmission is desired in the coupling 5, a valve (not shown) is operated to a shut-off position, whereby the pump 34 pumps the hydraulic fluid directly to the tank 33 'without the hydraulic fluid passing between the blades 13, 15.

Fig. 4 shows a detail of the slip coupling 5. Four bolts 35 and are substantially evenly distributed around its periphery. (of which only one is shown) are attached to the flange 31. The inductive first sensor 12 is mounted on a flange 36 projecting from the housing 33. The bolts 35 are adjusted so that they will be at a small distance from the sensor 12. A signal occurs in the connection line 37 of the sensor 12 each time a bolt 35 during the rotation of the flange 31 passes the sensor 12. The connection line 37 directs the signal from the sensor 12 to the calculation device 16.

The second sensor 14 is mounted in connection with the output shaft 6 according to the same principle as shown in Fig. 4.

Figure 5 shows the calibration curve K for the slip clutch 5. The measured speed V1, which is representative of the input shaft 3, is entered on the x-axis. The percentage difference P between the speed V1 and the second measured speed V2, which is representative of the output axis 6, is calculated and determines which curve to use. For example, at an input speed V1 of 2000 rpm and an output speed V2 of 1900 rpm, the percentage difference P in speed is thus (2000-1900) / 2000 = the curve corresponding to 5% speed difference can be y- 5%. When reading at V1 = 2000 rpm on the shaft, it is read that the torque M transmitted to the crusher 9 is 1680 Nm, counting device 16, the calibration curve K is converted as shown in Fig. 5. Using a method known to those skilled in the art to a mathematical relationship which gives very accurate values of moment M in real time.

It will be appreciated that a variety of modifications of the above-mentioned embodiment are possible within the scope of the invention.

For example, the inductive sensors 12, 14, which are a type of pulse sensor, can be replaced by another type of sensor for speed measurement, such as, for example, capacitive sensors, stroboscopes (pulsed light), limit position sensors or mechanical measuring devices with rollers. Often, for example, 10 is 15 20 25 30 35. .a .a - n. n- ~. n "_ _ _,... .- -. ... .- u. a. ._ _ _ ,,. .... a. nu a - -: I _ _ __, _ nn. ~ _ s: 2: _ _ _,,. a - a - .. a .... a - a .a .. .n a .. 12 diesel engines equipped with an internal speedometer.

This can then be used to measure the speed V1. As mentioned above, there are a plurality of positions 12 'where a first sensor can alternatively be placed and a plurality of positions 14' where a second sensor can alternatively be placed. The choice of location is governed by factors such as accessibility, easy installation, protected environment, etc.

The invention is suitable for several types of crushers.

In addition to gyratory crushers 9, the method and device can also be used in, for example, jaw crushers, impact crushers and roller crushers.

The control system 23 can be of several types known to those skilled in the art. An example of a useful control system is AsR PlusTM, which: illgiveralls by Svedala-Arbrå, sE.

The hydraulic slip clutch 5 can either be of the type which is continuously fed with hydraulic fluid and which thus completely stops transmitting power when the supply of hydraulic oil is stopped or of the type which always contains hydraulic oil and can therefore always transmit power.

The drive sources 2 that are primarily interesting are diesel engines, hydraulic engines and electric motors. In special cases, however, petrol engines and different types of turbines may also be relevant.

Torque M can also be measured in other ways than by speed measurement. For example, the output shaft 6 can be provided with a wire strain gauge which is placed at a certain angle and which measures the torsion in the shaft 6. However, this arrangement is relatively complicated.

The output shaft 6 can be very short and connect the second paddle 15 to a transmission 7 which in turn drives the crusher 9. Alternatively, the output shaft 6 can drive the crusher 9 directly. The transmission 7 can also have a wheel which is mounted directly on the paddle 15, the output shaft 6 being constituted by the paddle and the wheel mounted thereon.

In applications where an automatic control of the crusher 9 is not necessary, the calculation device 16 10 15 20 ... . u o: fl _ _ __ ,,. . . . - I I 0 I I I I U. ,. I um 223 (13 '"“' - ---: ~: ~ W - ~. W. - g ~ n - _ .. ~~ n... L3 is connected to a pointer instrument which shows the current moment M. The calculated torque M is often converted, as mentioned above, to an output in kW which can then be displayed on the display device 23. This conversion can be entered as a function in the calculation device 16 or the control system 23 or performed in another manner known to those skilled in the art. In an even simpler embodiment, only the measured speeds V1 and V2 are shown. In all cases, the signals can be connected to an alarm function. The alarm function can alarm both at high torque, which can indicate too much or too hard material in the crusher, and at low torque, which may, for example, indicate problems in the feeding device or in the part of the crusher where the material is fed.

In the case of jaw crushers, impact crushers and gyratory crushers, for example, the above-mentioned effect display often provides the information that the operator needs to see that the largest possible amount of material is fed into the crusher. He also gets indications of errors. For example, if a large object covers the intake to the crusher, the effect drops sharply.

Claims (12)

Pans 0003998-2 10 15 20 25 30 35 52 3 Û 3 7 l4 PATENTKRAV Crusher system, which comprises a crusher (9) (2), is arranged to and a drive source driven by the crusher (9) - characterized in that the drive source (2) (5) transmits power to drive a hydraulic slip clutch which via a shaft (6) extending from the coupling (5), the crusher (9), and that the crushing plant has a measuring (12, 14, 16), (12) representative of a second speed to the coupling (5) (3), which is arranged to measure by means of a (V1) device measuring unit a first speed which is input shaft (14) (V2), which is representative of the output (16) is arranged to be based on the measured speeds (V1, V2) and ( 5) determining as the output shaft (6) (23, monitoring and / or controlling the crusher (9) the determined torque (M), and measuring a single shaft (6) by means of a second measuring unit, a calculating device a calibration curve (K) the moment (M) of the coupling transmits to the crusher (9), wherein means 23 ') are arranged for depending on Crushing plant according to Claim 1, in which the drive source (2) has been selected from a group consisting of explosion engines and hydraulic motors. Crushing plant according to one of the preceding claims, in which the drive source (2) is a diesel engine. Crushing plant according to one of Claims 1 to 3, in which a first vane (13) (13, 15) is separated, the first being the slip clutch (5) and (15), from each other by means of a gap (12) speed and the other measuring unit (15) Crushing plant according to one of the preceding claims, which vanes (32) are arranged to measure the speed of the first vane (14). a second vane measuring unit (13) for measuring the second vane is arranged at which a display device (23 ') is arranged to display at least one value which is included in a group of values (M), which consists of the determined moment one of the 15 20 25 30 35 523 os? ». > a. .o 15 (M) calculated power (E), (Vl) and a measured second speed determined the torque a measured (V2). Crushing plant according to one of the preceding claims, first speed at which the crusher (9) is a gyratory crusher, a jaw crusher, a roller crusher or a percussion crusher. Crusher system according to one of the preceding claims, (23), operation in dependence on the determined torque which has a control system which is intended to control the crusher (9) (M). Crusher plant according to claim 7, in which the crusher (23) is arranged to, depending on the determined torque (M) (17) (18), be arranged on the gyratory crusher (9), control it (S). A crushing plant according to any one of the preceding claims, (9) is a gyratory crusher, the control system and signals from pressure and position sensors as the crushing gap width of the gyratory crusher (9) which is a mobile crushing plant. A method of monitoring the operation of a crushing plant, which comprises a crushing drive source (2), a hydraulic slip clutch (5) and a crusher (9) characterized in that an (2) output shaft is driven by the drive source that the crusher (9) (6) and that the torque is driven by one from the coupling (5) (M) which the output shaft (6) transmits to the crusher (9) is determined by means of a measuring (12, 14, 16 ) of the crushing plant (1) number (V1), (5) input shaft device for use in monitoring operation, a first revolution which is representative of one of the coupling (3), (V2), and a second speed which is »Representative of the output shaft (6), is measured and that said torque (M) is then determined by means of a calculation (16) (V1, V2) and a calibration curve (K) for the clutch (5). 11. ll. A method according to claim 10, wherein the crusher (9) (M). A method according to claim 10 or 11, in which a crushing device based on the measured speeds operation is controlled depending on the determined torque (9) is a gyratory crusher, wherein a control system (23) is used to use the determined torque ou nno nn nn ncøv In 1v0 ~ 4 I nn - nnnon nn nn nnn u. - u. ~ n. o c n n n n o n a n n n ~ n n n nu. nn; n n u n n. n n n n n. n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n (n) and signals from the crusher arranged on the crusher (17) and position sensors (18) control the crusher gap width (S) of the gyratory crusher (9).