Abstrict A method and apparatus are disclosed for monitoring the amount
of erosion in the wearing parts of a crusher, in which method the
wearing of the crusher is provided with a wear sensor that issues
a signal to the crusher's automatic control system as erosion in
the wearing part reaches a predetermined depth. Upon receiving the
signal, the control system initiates predetermined actions, such
as an alarm, stopping the crusher and/or ordering of a spare part.
Information on the amount of erosion in a wearing part is transmitted
wirelessly to the automatic control system.
Claims 1. A method for monitoring the amount of erosion in the wearing
parts of a crusher, in which method the erosion of the wearing parts
of a crusher is monitored by the crusher's automatic control system
and, as erosion in the wearing parts reaches a predetermined depth,
the control system initiates predetermined actions, which actions
comprise issuing an alarm, characterized in that information on
the amount of erosion in a wearing part of the crusher is transmitted
wirelessly to the automatic control system of the crusher and that
the predetermined actions further comprise at least one of the following
actions: stopping the crusher or stopping material infeed to the
crusher or ordering a wearing part for the crusher.
2. The method of claim 1 characterized in that the predetermined
depth of erosion of the wearing parts is such that the crusher operation
can be continued using the old wearing part during the delivery
time of the new wearing part.
3. The method of claim 1 characterized in that a plurality of
separate wear sensors connected to the crusher control system is
utilized so that different kind of actions are initiated depending
on the sensor of the system issuing an alarm.
4. An apparatus for monitoring the amount of erosion in the wearing
parts of a crusher, the apparatus comprising an automatic control
system of the crusher, and at least one wear sensor mounted on the
wearing part of the crusher, characterized in that said wear sensor
is equipped with means for transmitting the measurement signal wirelessly
to the automatic control system of the crusher and with a self-contained
energy source.
5. The apparatus of claim 4 characterized in that the self-contained
energy source comprises means for converting kinetic energy into
electrical energy.
6. The apparatus of claim 4 characterized in that the self-contained
energy source comprises a piezoelectric device for generating electrical
energy.
7. The apparatus of claim 4 characterized in that the self-contained
energy source comprises means for capturing electrical energy from
an electromagnetic field launched about the crusher.
8. The apparatus of claim 4 characterized in that the wear sensor
comprises a conductor embedded in an insulator.
9. The apparatus of claim 5 characterized in that the wear sensor
comprises a conductor embedded in an insulator.
10. The method of claim 2 characterized in that a plurality of
separate wear sensors connected to the crusher control system is
utilized so that different kind of actions are initiated depending
on the sensor of the system issuing an alarm.
11. The apparatus of claim 5 characterized in that the wear sensor
comprises a conductor embedded in an insulator.
12. The apparatus of claim 6 characterized in that the wear sensor
comprises a conductor embedded in an insulator.
13. The apparatus of claim 7 characterized in that the wear sensor
comprises a conductor embedded in an insulator.
14. The apparatus of claim 6 characterized in that the wear sensor
comprises a conductor embedded in an insulator.
15. The apparatus of claim 7 characterized in that the wear sensor
comprises a conductor embedded in an insulator.
16. The apparatus of claim 8 characterized in that the wear sensor
comprises a conductor embedded in an insulator.
Description [0001] The invention relates to the monitoring of the amount of
erosion in the wearing parts of crushers. More specifically, the
invention relates to crushers equipped with an automatic control
system.
[0002] Wear monitoring of the wearing parts in a crusher is vital
to avoid "wear-through" of a wearing part resulting in
a considerably expensive and time-consuming repair of the crusher
as compared with a normal replacement of the crusher's wearing part.
[0003] In patent publication U.S. Pat. No. 6129297 is disclosed
one method of monitoring the progress of wear in the wearing parts
of a crusher. According to this invention, on the rear surfaces
of the wearing parts in the crusher are made recesses reaching up
to a depth that represents the maximum allowable degree of wear
of the wearing parts in the crusher. The recesses are filled with
a suitable material such as a color composition. When the erosion
of the wearing parts eventually reaches a point that reveals the
recesses, the color composition spreads onto the surfaces of the
wearing parts of the crusher, wherefrom the wear indication is easy
to detect by the crusher operator. However, this kind of arrangement
fails to provide on-line wear information during crushing inasmuch
as the crusher must always be stopped for inspection thus causing
losses in production capacity. Moreover, the amount of erosion can
be monitored only by climbing onto the crusher, a task that invariably
involves a risk of operator safety.
[0004] The present invention is based on equipping the wearing
parts of a crusher with wear sensors that at the instant of the
wearing parts reaching a given degree of wear deliver a signal to
the crusher's automatic control system. Based on this signal, the
automatic control system issues an alarm and/or stops the crusher.
The control system may optionally be complemented with an automatic
ordering system of wearing parts, whereby setting the wear sensor
to alarm at a predetermined wear threshold, the automatic control
system may launch a spare part order in order to have the spare
part available on-site when monitored wear parts of the crusher
reach the end point of their service life requiring a replacement
part.
[0005] More specifically, the method according to the invention
is characterized by what is stated in the characterizing part of
claim 1 and the apparatus according to the invention is characterized
by what is stated in the characterizing part of claim 5.
[0006] In the following, the invention will be examined in more
detail by making reference to the appended drawing in which
[0007] FIG. 1 shows a crusher control system according to the invention.
[0008] Referring to FIG. 1 therein is shown the adaptation of
an apparatus according to the invention to the construction of a
gyratory crusher 1. The wearing parts of the gyratory crusher, namely
an inner liner 2 and an outer liner 3 are equipped with wear sensors
4 5. The functions of the crusher are steered by an automatic control
system 6 of the crusher.
[0009] In the illustrated exemplary embodiment, the wear sensors
are embedded at predetermined depths in the crusher liners. As the
amount of erosion reaches the level of the sensors, the sensors
either start to transmit a signal to the crusher's automatic control
system that then performs certain preprogrammed functions or, alternatively,
cease to send a signal, whereupon the control system after the lapse
of a predetermined delay performs the preprogrammed functions.
[0010] Upon receiving an alarm signal from the sensors, the automatic
control system may either forward the alarm to the crusher operator
or alternatively automatically stop the crusher. In its simplest
form, the control system issues the alarm as a visual or acoustic
signal. The control system may optionally be complemented with automatic
routines of spare part ordering, whereby the control system upon
the receipt of the wear threshold signal issues the spare part order.
To this end, the wear sensors must be embedded at a correct depth
in the wearing parts such that the crusher operation can be continued
using the old wearing part during the delivery time of the new wearing
part.
[0011] In its simplest form, the sensor embedded in the wearing
part may comprise a conductor loop surrounded by an insulating material.
Hereby, an alarm is issued at the instant the loop is interrupted
due to wear. Alternatively, the system may be equipped with other
kinds of simple on-off type switches or sensors.
[0012] The signal issued by a sensor embedded in a given wearing
part may also be transmitted wirelessly to the exterior side of
the crusher by means of a separate transmitter connected to the
sensor. Respectively, the crusher's automatic control system must
be equipped with a compatible receiver. By complementing the wear
sensor with an integral power supply, the compact sensor package
can be either embedded entirely in a wearing part of the crusher
or, alternatively, adapted between the wearing part and the surface
supporting the same, whereby all complications due to sensor wiring
are avoided.
[0013] In the former case, the operating energy of the sensor can
be delivered, for example, by a battery. The integrated sensor package
may also be provided with a piezoelectric device capable of generating
electrical energy. One useful type of self-contained energy source
is a mechanical converter of kinetic-to-electrical energy such as
is used in wristwatches, for instance. One further alternative way
of generating the operating power of the sensor is energy capture
by means of RF techniques from an electromagnetic field surrounding
the crusher.
[0014] In the prior art it has been conventional to use the crusher's
control system also for controlling both the material infeed machinery
and the crushed material discharge machinery. Now, the wear sensors
can be configured to control the entire machinery system in such
a fashion that, e.g., at an alarm issued by a wear sensor, material
infeed into the crusher is stopped.
[0015] The invention may also be implemented by way of utilizing
a plurality of separate wear sensors connected to the crusher control
system so that different kinds of actions are initiated depending
on the sensor of the system issuing an alarm. In this fashion, e.g.,
an amount of erosion reaching a predetermined depth first triggers
a warning alarm of exhausting wearing parts to the crusher operator.
If the crusher operator fails to respond to the warning and allows
the amount of erosion to progress down to a second depth level,
the control system may be allocated to stop the crusher thus preventing
operator negligence from causing damage to the crusher.
[0016] The invention is not limited to any given type of crusher,
but instead may be adapted to all kinds of crushers equipped with
wearing parts.
[0017] Further, the invention is not limited to the wear sensors
of a given type, but instead may utilize any type of sensor capable
of monitoring the amount of erosion in the wearing parts of crushers.
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