Method of operating a mineral material processing plant with braking energy recovery

Abstract

A method of operating a mineral material processing plant, comprising monitoring the load of a mineral material processing device (110) of the mineral material processing plant (100) and / or the amount of material using a control element (130); determining that the load and / or the amount of material has exceeded a predetermined threshold value; in response to the determination that the load and / or the amount of material has exceeded the predetermined threshold value stopping or slowing down a feed conveyor (125) of the mineral material processing plant; recovering the energy created during braking of the feed conveyor; and directing the energy recovered to power the mineral material processing device (110) and / or to an energy storage (160)

Description

[0001] METHOD OF OPERATING A MINERAL MATERIAL PROCESSING PLANT WITH

[0002] BRAKING ENERGY RECOVERY

[0003] TECHNICAL FIELD

[0004] The present disclosure generally relates to a mineral material processing plant and a method of operating a mineral material processing plant. The disclosure relates particularly, though not exclusively, to a mineral material processing plant with an electric drive. The disclosure relates particularly, though not exclusively, to a mineral material processing plan with braking energy recovery.

[0005] BACKGROUND

[0006] This section illustrates useful background information without admission of any technique described herein representative of the state of the art.

[0007] Mineral material processing is increasingly moving towards electric and hybrid power generation. During operation of a mineral material processing plant, the power requirements vary. For example material that is harder to process might require more power at certain times.

[0008] The load of mineral material processing devices is monitored, as is the amount of material being processed, situations with increased power requirements can be identified and appropriate action taken.

[0009] The present disclosure aims to provide a mineral material processing plant in which braking energy is recovered and can be used in situations requiring more power.

[0010] SUMMARY

[0011] The appended claims define the scope of protection. Any examples and technical descriptions of apparatuses, products and / or methods in the description and / or drawings not covered by the claims are presented not as embodiments of the invention but as background art or examples useful for understanding the invention.

[0012] According to a first example aspect there is provided a method of operating a mineral material processing plant, comprising monitoring the load of a mineral material processing device of the mineral material processing plant and / or the amount of material using a control element; determining that the load and / or the amount of material has exceeded a predetermined threshold value; in response to the determination that the load and / or the amount of material has exceeded the predetermined threshold value stopping or slowing down a feed conveyor of the mineral material processing plant; recovering the energy created during braking of the feed conveyor; and directing the energy recovered to power the mineral material processing device (110) and / or to an energy storage.

[0013] The mineral material processing device may comprise a crusher.

[0014] Determining that the load and / or the amount of material has exceeded the predetermined threshold value may comprise determining that the load and / or the amount of material has exceeded a predetermined threshold value for a predetermined time.

[0015] Monitoring the amount of material may comprise monitoring the level of material in the crushing chamber of the crusher and / or monitoring the amount of material arriving to be processed.

[0016] Directing the energy recovered to power the mineral material processing device may comprise directing the energy directly to the mineral material processing device or via the energy storage.

[0017] Stopping or slowing down a feed conveyor may comprise stopping or slowing down a feeder selected from the group of an apron feeder, a belt feeder, a vibrating feeder, a vibrating grizzly feeder, a pan feeder, a wobbler feeder and a combination of said feeders.

[0018] According to a second example aspect there is provided a mineral material processing plant, comprising a mineral material processing device; and a control element; wherein the control element is configured to cause operating the mineral material processing plant according to the method of the first example aspect.

[0019] The mineral material processing device may comprise a crusher.

[0020] Different non-binding example aspects and embodiments have been illustrated in the foregoing. The embodiments in the foregoing are used merely to explain selected aspects or steps that may be utilized in different implementations. Some embodiments may be presented only with reference to certain example aspects. It should be appreciated that corresponding embodiments may apply to other example aspects as well.

[0021] BRIEF DESCRIPTION OF THE FIGURES

[0022] Some example embodiments will be described with reference to the accompanying figures, in which:

[0023] Fig. 1 schematically shows a block view of a mineral material processing machine according to an example embodiment; and

[0024] Fig. 2 shows a flow chart of a method according to an example embodiment.

[0025] DETAILED DESCRIPTION

[0026] In the following description, like reference signs denote like elements or steps.

[0027] Fig. 1 schematically shows a block view of a mineral material processing machine, or plant, 100 according to an example embodiment. In an example embodiment, the mineral material processing machine 100 comprises a mobile mineral material processing machine such as a mobile crusher or a mobile screen. In an example embodiment, the mineral material processing plant comprises a plurality of mineral material processing machines, i.e. the term mineral material processing plant in an embodiment refers to a single mineral material processing machine, such as a mobile crusher, or to a plurality of mineral material machines being operated together.

[0028] The mineral material processing machine 100 comprises a processing device 110. In an example embodiment, the processing device 110 comprises a crusher. In an example embodiment, the crusher is selected from the group of jaw crusher, cone crusher and gyratory crusher

[0029] In a further example embodiment, the mineral material processing machine comprises more than one processing device 110, for example both a crusher and a screen.

[0030] In an example embodiment, the mineral material processing machine comprises a feed conveyor 125. In an example embodiment, the feed conveyor 125 comprises a feeder selected from the group of an apron feeder, a belt feeder, a vibrating feeder, a vibrating grizzly feeder, a pan feeder, a wobbler feeder and a combination of said feeders.

[0031] The mineral material processing machine 100 comprises at least one further actuator, or device, 120 directly or indirectly participating in mineral material processing. The at least one further actuator, in an example embodiment, comprises a conveyor, a feed chute, a magnetic separator and / or actuators for moving, e.g. raising and lowering, parts of the mineral material processing machine.

[0032] The mineral material processing machine 100, in an example embodiment, comprises a motor 140, for example a diesel motor, and a generator 150 coupled to the motor 140 for generating electric power.

[0033] The mineral material processing machine 100, in an example embodiment, comprises means for connecting the machine to an external source of electric power 10, such as power grid.

[0034] The mineral material processing machine 100, in an example embodiment, comprises at least one energy storage 160, such as a battery, a battery module and / or a large capacity capacitive element for providing electric power.

[0035] In an example embodiment, the mineral material processing machine 100 comprises a switch 15 configured to switch between internally generated electric power, energy storage 160 and the external electric power source 10.

[0036] The mineral material processing machine 100, in an example embodiment, comprises a control element 130. The control element 130 is in an example embodiment configured to control the power distribution of the mineral material processing machine 100. The control element 130 is connected to the electric components of the mineral material processing machine, such as the drives of the mineral material processing device 110, the feed conveyor 125 and the at least one actuator 120 in order to provide electric power and to control the drives.

[0037] In an example embodiment, the control element 130 is further configured to control the motor 140 and the generator 150. In an example embodiment, the control element 130 is further configured to operate the switch 15, i.e. configured to choose and change the source of electric power.

[0038] In an example embodiment, the control element 130 is configured to measure, and to monitor, the load of the mineral material processing device, i.e. a crusher, 110. The load measurement is carried out by conventional measurement means. In an example embodiment, the control element 130 is further configured to measure, and to monitor, the amount of material in the, and / or arriving to, the mineral material processing device 110. In an example embodiment, the amount of material is measured by measuring the level of the material at the mineral material processing device 110.

[0039] In an example embodiment, the control element 130 is configured to stop or to slow down the feeding of the material into the mineral material processing device 110 in case the load and / or the amount of material exceeds a predetermined threshold by causing stopping the feed conveyor 125.

[0040] In an example embodiment, the feed conveyor is a vibrating feeder or a vibrating grizzly feeder comprising a motor, preferably a motor generator, or a further device transforming electric energy to mechanical energy or vice versa, connected to a vibrator that has eccentric counterweights creating the wanted stroke to enable efficient high capacity output for material to be moved on the surface of the feed conveyor and to be fed in the processing machine.

[0041] In an example embodiment, stopping the feed conveyor using a rapid braking sequence generates energy that has previously been turned to heat using braking resistance elements and been dissipated. In an example embodiment, the control element 130 is configured to control the electric drive and the motor of the feed conveyor in such a way that the braking energy is recovered.

[0042] In an example embodiment, the control element 130 is configured to cause directing at least a part of the energy recovered by braking the feed conveyor to operate the mineral material processing device in the ongoing situation of high load and / or high amount of material.

[0043] In a further example embodiment, the control element 130 is configured to cause directing at least a part of the energy recovered by braking the feed conveyor to the energy storage 160.

[0044] In an example embodiment, the control element 130 is configured to control the electric motors or motors of the feed conveyor 125. The control element 130 is configured to, in the situation in which the feed conveyor is to be stopped or slowed down, to cause converting the mechanical energy of the feed conveyor motor into electric energy. In an example embodiment, the electric energy is distributed to other actuators of the mineral material processing machine, in particular to the processing device. In an example embodiment the electric energy is distributed via a direct current, DC, connection.

[0045] In an example embodiment, the direct current connection for distributing the recovered braking energy is provided with protection against excessive currents, over- and under voltage and voltage fluctuations.

[0046] Examples of the operation of the braking energy recovery according to an example embodiment are as follows. During operation of the mineral material processing plant situations arise in which the mineral material processing device, i.e. a crusher, 110 experiences an increased load. Such situations arise for example in case the material being crushed is harder or more difficult to crush for other reasons or contains uncrushable material. Accordingly, the load of the crusher, and the power requirement thereof rises, and the amount of material in the crusher, i.e. the surface level in the crushing chamber may begin to rise in an undesirable manner. The control 130 element monitoring the operations of the mineral material processing machine, or plant, 100 notices the rise of the load and / or the rise of the amount of material and is configured to stop or slow down the feeding of material. As the feed conveyor 125 is stopped or slowed down, the energy from the braking sequence is recovered and directed to power the crusher and / or to the energy storage 160. In a further example, if the feed conveyor needs to be stopped in an emergency, for example for safety reasons, the braking energy recovery is not carried out, but the drive of the feed conveyor is simply put on neutral gear.

[0047] Fig. 2 shows a flow chart of a method according to an example embodiment.

[0048] At step 210, the mineral material processing machine, or plant, is operated and the load of the mineral material processing device 110 is monitored and / or the amount of material being processed, for example the surface level at the crushing chamber is monitored. In an example embodiment, further quantities are monitored in addition to or instead of the load or amount of material. For example, a load of a mineral material processing device of another mineral material processing machine is monitored.

[0049] At step 220, the load and / or amount of material exceeds a threshold value. In an example embodiment, the threshold value is predetermined. In a further example embodiment, the threshold value is variable and is changed in accordance with the operating situation. In an example embodiment, the load and / or amount of material is considered as having exceeded the threshold value after the threshold value has been exceeded for a predetermined time, i.e. a momentary load and / or material amount exceeding the threshold value is not considered as having exceeded the threshold.

[0050] At step 230, in response to the determination that the threshold has been exceeded at step 220, the feed conveyor is stopped or slowed down by braking the feed conveyor. The controls element 130 is configured to cause the braking in response to determination of the threshold value having been exceeded.

[0051] At step 240, the braking energy of the feed conveyor is recovered and at step 250 the recovered energy is directed to power the mineral material processing device, i.e. crusher, 110 or directed to the energy storage 160. In an example embodiment, the recovered energy is directed outside of the mineral material processing machine 100, for example to a further mineral material processing machine or an external energy storage. In an example embodiment, the energy recovered is directed directly to the mineral material processing device 110. In a further example embodiment, the energy recovered is directed to the mineral material processing device 100 via the energy storage 160.

[0052] Without in any way limiting the scope of the appended claims, some technical effects of the method and mineral material processing machine according to example embodiment are explained in the following.

[0053] The method according to example embodiments is configured to recover energy created in stopping or slowing down the feed of a mineral material processing machine, method according to example embodiments is further configured to enable a momentary increase in energy available to a crusher of a mineral material processing machine.

[0054] Accordingly, a technical effect of example embodiment of the invention is to provide more energy security during operation. A further technical effect of the example embodiments of the invention is to reduce heat production. A still further technical effect of the example embodiments of the invention is to enable a more environmental friendly operation with less loss of energy. A still further technical effect of the example embodiments of the invention is to enable load balancing.

[0055] Various embodiments have been presented. It should be appreciated that in this document, words comprise; include; and contain are each used as open-ended expressions with no intended exclusivity.

[0056] The foregoing description has provided by way of non-limiting examples of particular implementations and embodiments a full and informative description of the best mode presently contemplated by the inventors for carrying out the invention. It is however clear to a person skilled in the art that the invention is not restricted to details of the embodiments presented in the foregoing, but that it can be implemented in other embodiments using equivalent means or in different combinations of embodiments without deviating from the characteristics of the invention.

[0057] Furthermore, some of the features of the afore-disclosed example embodiments may be used to advantage without the corresponding use of other features. As such, the foregoing description shall be considered as merely illustrative of the principles of the present invention, and not in limitation thereof. Hence, the scope of the invention is only restricted by the appended patent claims.

Claims

CLAIMS1 . A method of operating a mineral material processing plant, comprising monitoring the load of a mineral material processing device (110) of the mineral material processing plant (100) and / or the amount of material using a control element (130); determining that the load and / or the amount of material has exceeded a predetermined threshold value; in response to the determination that the load and / or the amount of material has exceeded the predetermined threshold value stopping or slowing down a feed conveyor (125) of the mineral material processing plant; recovering the energy created during braking of the feed conveyor; and directing the energy recovered to power the mineral material processing device (110) and / or to an energy storage (160).

2. The method of operating a mineral material processing plant of claim 1 , wherein the mineral material processing device (110) comprises a crusher.

3. The method of operating a mineral material processing plant of claim 1 or 2, wherein determining that the load and / or the amount of material has exceeded the predetermined threshold value comprises determining that the load and / or the amount of material has exceeded a predetermined threshold value for a predetermined time.

4. The method of operating a mineral material processing plant of claim 2 or 3, wherein monitoring the amount of material comprises monitoring the level of material in the crushing chamber of the crusher and / or monitoring the amount of material arriving to be processed.

5. The method of operating a mineral material processing plant of any preceding claim, wherein directing the energy recovered to power the mineral material processing device comprises directing the energy directly to the mineral material processing device or via the energy storage.

6. The method of operating a mineral material processing plant of any preceding claim, wherein stopping or slowing down a feed conveyor comprises stopping or slowing down a feeder selected from the group of an apron feeder, a belt feeder, a vibrating feeder, a vibrating grizzly feeder, a pan feeder, a wobbler feeder and a combination of said feeders.

7. A mineral material processing plant, comprising a mineral material processing device (110); and a control element (130); characterized in thatthe control element (130) is configured to cause operating the mineral material processing plant according to the method of any preceding claim 1-6.

8. The mineral material processing plant of claim 7, wherein the mineral material processing device (110) comprises a crusher.

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