• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    The present invention relates to a method for determining a change of a flushing medium flow in a rock drilling device, wherein a compressor emits a flow of pressurized gas, said gas flow being at least partially used as flushing medium when drilling with a tool, wherein, during drilling, said flushing means for flushing. flushing away of drilling debris. The method includes determining a rate of a pressure change for said purge medium, and generating a signal when said rate exceeds a first value. The invention also relates to a system and a rock drilling device. Fig. 5 76227; 2010-08-26
    公开号:SE1000870A1
    申请号:SE1000870
    申请日:2010-08-26
    公开日:2012-02-27
    发明作者:Erik Alden
    申请人:Atlas Copco Rock Drills Ab；
    IPC主号:
    专利说明:

    Common to the above drilling principles is that the rock is crushed during drilling, whereby drilling residues, so-called drill cuttings, are formed, which must be evacuated from the borehole in order for the drilling to be carried out in an efficient manner.
    This is usually done by means of a rinsing medium, such as e.g. compressed air, purge air, which is led through a duct in the drill string for discharge through purge air holes in the drill bit to then take the drilling residues with them on their way out of the hole.
    In rock drilling, such as, but not limited to, top hammer drilling, there is a risk that the flushing holes in the drill bit are blocked by drilling residues during drilling, thus preventing the flushing air from flushing away the drilling residues. If the purge air is prevented from flushing the hole from the drilling residues, drilling residues will begin to build up around the drill bit, which leads to the drilling deteriorating and the drill bit in the worst case getting stuck completely.
    Thus, systems are required to detect and prevent such situations from occurring, e.g. by generating a warning signal if the purge air flow drops to too low a level, whereby applicable measures can be taken.
    Today, in drilling rigs where a flushing medium consisting mainly of compressed air is used, a so-called between compressor and drill string is used. venturirör. A pressure switch measures the differential pressure across the venturi tube, where the pressure difference across the tube increases with increased flow through the tube.
    The pressure switch is set in such a way that a signal is generated when the pressure difference across the venturi, and thus also the purge air flow, is below a set level.
    However, this solution has several disadvantages. In addition to the fact that the solution is relatively expensive, sensitive and difficult to 76227; 2010-08-26 10 15 20 25 30 set correctly, the pressure switch consists of an analog sensor that can not be controlled via e.g. software. Due to difficulties in setting up the pressure switch, which is usually done manually using e.g. adjusting screws, it is also not possible to adjust the pressure difference level at which the pressure switch generates a signal according to different operating points, which means that the pressure switch can function better in certain conditions prevailing during rock drilling compared with situations with other prevailing conditions.
    Thus, there is a need for an improved method for determining changes in purge air flow during rock drilling.
    SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for determining a change in a purge air flow in a rock drilling device which solves the above problems. This object is achieved with a method according to claim 1.
    The present invention relates to a method for determining a change of a flushing medium flow in a rock drilling device, wherein a compressor emits a flow of pressurized gas, said gas flow being used at least partially as flushing medium when drilling with a tool, wherein, during drilling, said flushing medium led to said tool for flushing away drilling residues. The method comprises determining a rate of a pressure change for said flushing medium, and generating a signal when said determined rate exceeds a first value.
    The present invention has the advantage that a method for determining a flushing medium flow change, and in particular a flushing medium flow reduction, is obtained, which is 76227; 2010-O8 ~ 26 10 15 20 25 30 independent of the actual working pressure prevailing in the flushing medium system / circuit.
    In general, the actual working pressure of the flushing medium system can change significantly during drilling.
    For example. only the part of the purge air pressure relating to the flow resistance up to the drill bit may be more than twice as large, or even larger, at the end of the drilling of a hole, when many drill rods are joined in the drill string, compared to at the beginning of the drilling when only one drill rod is used.
    By determining according to the present invention the rate at which a pressure change occurs in the flushing medium circuit, this rate can be used to represent the difference between the flow supplied to the flushing medium circuit and the flow actually flowing out through the drill bit, whereby a change can be determined independently of current working pressure. The pressure change can e.g. determined by means of a pressure sensor, wherein two or more successive pressure determinations can be performed to determine said pressure change.
    The invention also has the advantage that determination / detection of a flow change can take place before the pressure in the system has risen to e.g. a maximum pressure level, which in turn means that the rock drilling device's control system and / or operator can be alerted to the impending problem earlier than has previously been possible. Thus, it is also possible that measures to remedy problems with ongoing clogging can be taken at an earlier stage.
    The present invention is particularly applicable to systems where a flow controlled compressor is used to generate said flushing medium flow. In flow-controlled compressors, the working pressure usually differs significantly (the working pressure is lower) 76227; 2010-08-26 lO 15 2 N1 O UI from the compressor / purge air circuit's maximum permissible working pressure. In such situations, the present invention provides a solution that can more quickly generate a warning signal compared to the prior art, where the working pressure must first increase to the maximum allowable pressure before a flush air flow decrease is detected.
    Brief Description of the Drawings Fig. 1 shows a rock drilling device to which the present invention can be advantageously applied.
    Fig. 2 shows a system for determining a purge air flow change according to an exemplary embodiment of the present invention.
    Fig. 3 shows a system for determining a purge air flow change according to the prior art.
    Fig. 4 shows the pressure change of the flushing medium flow over time.
    Fig. 5 shows a flow chart of an exemplary method according to the present invention.
    Detailed Description of Exemplary Embodiments Fig. 1 shows a rock drilling device according to a first exemplary embodiment of the present invention, for which a monitoring of the purge air flow according to the invention will be described.
    The rock drilling device shown in Fig. 1 comprises a drilling rig 1, in this example an above-ground drilling rig, which carries a drilling machine in the form of a top hammer drilling machine 11.
    The drilling rig 1 is shown in use, drilling a hole 2 in rock, which begins at the earth's surface and where the drilling is currently 76227; 2010 ~ 08-26 10 l5 20 25 30 is at a depth d. The hole is intended to result in a hole with the depth ß, which, depending on the application area, can vary greatly from hole to hole and / or application area to application area. The completed hole is indicated by dashed lines. (The ratio shown between drilling rig height and hole depth is in no way intended to be proportional. The total height y of the drill can be, for example, 10 meters, while the holding depth ß can be both less than and substantially much greater than 10 meters, e.g. meters, 30 meters, 40 meters or more.) The top hammer drilling machine ll is mounted on a feed beam 5 via a drill carriage 5. The feed beam 5 is in turn attached to a boom 19 via a feed beam holder 12. The top hammer drilling machine 11 provides, via a supported drill string 6 of a drill string support 14, the impact action of a drilling tool in the form of a drill bit 3, which transmits shock wave energy from the top hammer drill 11 to the rock. For practical reasons (except possibly for very short holes) the drill string 6 does not consist of a drill rod in one piece, but usually consists of a number of drill rods. When the drilling has progressed corresponding to a length of drill rod, a new drill rod is joined to the one or more drill rods already joined, whereby the drilling can proceed another drilling rod length before a new drill rod is joined to existing drill rods.
    The top hammer drilling machine 11 is of the hydraulic type, it being powered by a hydraulic pump 10, which in turn is driven by a power source in the form of an internal combustion engine 9 (such as a diesel engine) via hoses (not shown) in the usual way.
    Alternatively, the power source 9 may consist of e.g. an electric motor.
    A flushing medium, in the present example compressed air, flushing air, is used to flush the boreholes from the drill cuttings formed during the drilling so that the drilling can 76227; 2010-O8 ~ 26 10 15 20 25 30 is carried out in an efficient manner (the rinsing medium may also include additives. For example, water, with or without additives, may be added to the purge air).
    In the rock drilling device shown, the purge air is led from a compressor 8 via a tank. In the present example, an oil-lubricated compressor is used, the tank being a separator tank (see description in connection with Figs. 2-3 below). In one embodiment, the compressor is a non-oil lubricated compressor, whereby another type of tank can be used. Alternatively, no tank is used at all. From the tank, the purge air is led via hoses to the drill string to be led through the drill rods, which consist of thick-walled_pipes, e.g. steel. A channel formed in or through the walls of the rods in the longitudinal direction through the drill string is used to direct the purge air from the drilling rig 1 through the drill string 6 for discharge through the purge air in the drill bit, to then take the drill cuttings on their way out of the hole.
    The purge air flushes the drill cuttings upwards through, and out of the hole 2 in the space between the drill rod and the hole wall, as indicated by the upward arrows in Fig. 1 (in an alternative embodiment the cuttings are flushed out of the hole through a channel in the drill string, the flushing medium being led down a other channel formed in the drill string).
    Regardless of the flow path, in order for the drill cuttings to follow the purge air out of the hole, it is required that the purge air reaches at least a certain flow rate. This minimum flow rate required for the drill cuttings to follow up out of the hole, and not be left with clogging problems as a result, is primarily due to u. .
    . It is important that (T ^ C FT on the size, shape and density of the north cuttings is large enough for the cuttings to follow up to the surface, as too low a flow rate can impair drilling performance, and in the worst 76227; 2010-08-26 10 At the same time, it is important that the velocity of the purge air flow, on the other hand, is not unnecessarily high, since an excessive flow leads to increased energy consumption, and also to increased wear of components due to the blasting effect caused by the drill cuttings. the purge air carries out of the hole.
    The drilling rig also comprises a control unit 18, which forms part of the drilling rig's control system, and which can be used for controlling various functions, such as e.g. the monitoring of the purge air flow according to the present invention, as below.
    The compressor 8 is driven by the internal combustion engine 9, and according to the present example a screw compressor is used to push the purge air through the duct in the drill rods down to the drill bit 3. A screw compressor constitutes a compressor with fixed displacement. In the embodiment shown, the compressor 8 is directly connected to the internal combustion engine, which means that a change in the speed of the internal combustion engine will be directly reflected by a corresponding change in the speed of the compressor 8. In an alternative embodiment, the compressor is connected to the power source via some suitable type of gear unit. Furthermore, the compressor according to the embodiment shown is flow-controlled, ie. the compressor is controlled in such a way that the desired flow is delivered independently of the pressure which the compressor flow gives rise to in the subsequent purge air circuit, as long as the maximum pressure of the system has not been reached.
    The flow from a compressor with fixed displacement can in principle be controlled according to two different principles, one of which consists of a regulation of the compressor's speed. The flow from a compressor with fixed displacement is directly proportional to the speed of the compressor, and in those cases the power source of the compressor (in this case the internal combustion engine 9) can be speed controlled freely 76227; Thus, the flow delivered by the compressor can also be controlled to an arbitrary level between 0 and 100% of the compressor's capacity only by means of speed control.
    However, the compressor and / or perhaps above all the power source can have a minimum speed, e.g. p.g.a. that an internal combustion engine must pour at least one idle speed in order to be able to start at all, whereby the practically possible lower limit for speed control often consists of a certain minimum speed, which also introduces a limitation on how little flow the compressor can emit by means of speed control only. In addition, there are often other consumers connected to the power source, such as the said hydraulic pumps 10, 15, which, in order to obtain sufficient power, may require a higher internal combustion engine speed than is currently required by the compressor in order to be able to deliver the desired flow. In one embodiment, therefore, the compressor is controlled in such a way that it emits the lowest possible flow as long as this is equal to or exceeds the desired flow. The flow of the compressor can also be controlled by controlling the inlet valve of the compressor. By controlling the negative pressure in the compressor inlet in a controlled and desired manner by means of the inlet valve, the flow emitted by the compressor can be regulated to exactly the desired flow.
    In an alternative embodiment, therefore, the compressor is controlled according to this second principle.
    The control of the compressor flow can e.g. also be arranged to be controlled according to the method described in the parallel application "Device and method for rock drilling", with the same inventor and submission date as the present application.
    According to the method described in said application, a solution is shown in which the compressor operates according to a first mode and a second mode, respectively, and in which in said first mode the emitted flow of the compressor is arranged to be controlled by 76227; 2010-08-26 10 15 20 25 30 10 control of the speed of said compressor, and where in said second mode the flow delivered by the compressor is arranged to be controlled by controlling the air flow at the inlet of the compressor. Thus, the speed requirements of the compressor can be arranged to be determined according to the method described in said application.
    Determination of the flow to be delivered by the compressor can be determined by the control unit 18 and be based on one or more different parameters. For example. determination of purge air flow can be based on the actual depth of the borehole. The flow of the compressor can also, in whole or in part, be based on the hole dimension, drill rod dimension, the drilling machine's percussion effect (percussion pressure and / or percussion frequency) so that, regardless of percussion effect, it can always be ensured that the flow is matched to the drill cuttings generated during drilling.
    The purge air flow can of course also be controlled independently of the percussion pressure. Consideration can also e.g. is taken to the type of rock, whereby the purge air flow can be regulated at least in part depending on the rock type in which drilling takes place.
    The control of the flow delivered by the compressor can also be based on other parameters.
    As mentioned, according to the prior art, a venturi is applied to detect a flow change in the purge air circuit. For the sake of understanding, Fig. 3 shows an example of a system for detecting problems with the purge air flow according to the prior art. The system includes a compressor 301 for generating compressed air / purge air. The air that is compressed is taken from the environment of the compressor, and is supplied to the compressor 301 via an inlet valve 302. The pressurized air is led to a compressor tank / separator tank 303, where the oil 76227 supplied in the usual manner during compression; 2010-08-26 10 15 20 25 30 ll is separated from the compressed air to be used again as a lubricant in the compression of air.
    The compressed air is then passed on, via a venturi 304 and hoses 305, to the drill string 306 to be discharged at its opposite end through the hole of the drill bit for evacuating drill cuttings from the borehole.
    Venturi tubes are well known, and consist in principle of a tube which tapers towards the middle from both ends, the tube thus having a smaller diameter in the middle compared to its ends. As the cross-sectional area of the pipe decreases, the flow rate of the flow increases, which, since the energy content of the flow is substantially constant, according to known equations means that the pressure decreases.
    By measuring the pressure before and in the middle of the taper by means of a differential pressure gauge 310, a pressure difference can be determined, where the pressure difference will depend on the flow. This pressure difference is then used to determine changes in flow. Venturi tubes are well described in the prior art, and are therefore not described in more detail here.
    Furthermore, a pressure gauge 307 is arranged to measure the pressure in the compressor tank 303 (or at another location suitable on the high pressure side of the compressor) and provides a regulator 308 with signals from the pressure gauge 307. The pressure gauge 307 is an analog pressure gauge and the regulator 308 is an analog regulator. The regulator 308 regulates the pressure emitted by the compressor 301 against a reference pressure 309. The reference pressure is usually set by means of e.g. a knob that is operated manually. The knob can e.g. be factory set in such a way that the reference pressure corresponds to the maximum pressure that may be used in the system. The maximum pressure is usually set to a level that does not pose a risk of component damage due to too high a pressure level. 76227; 2010 ~ O8-26 lO l5 20 25 30 12 The reference pressure 309 can be changed by means of said knob.
    For example. In some cases, the drilling rig operator may lower the reference pressure in situations where the operator knows for sure that the drilling will not require the maximum capacity that the system can deliver. Many times, however, the factory-set setting is left completely unaffected.
    The regulator 308 regulates the working pressure of the compressor 301 by means of mechanical control of the inlet valve 302. If the working pressure of the compressor 301 is lower than the reference pressure 309, the opening to the inlet of the compressor 301 is made larger by the inlet valve 302. If, on the other hand, the working pressure 30 of the compressor the opening towards the compressor inlet is made smaller by means of the inlet valve 302.
    By continuously regulating the degree to which the inlet valve is open, the working pressure of the compressor can thus be continuously regulated.
    This thus means that when the pressure of the compressor tank 303 is equal to the reference pressure, the inlet valve will be completely closed, in order to open again if the pressure of the compressor tank drops below the reference pressure. In other words, for any given pressure in the compressor tank, the resulting purge air flow (the flow out of the compressor tank) can be 0 ~ 100% of the maximum flow that the compressor can deliver. Thus, if the purge air heel in the drill bit is clogged so that the purge air cannot pass, the pressure in the compressor tank will be regulated to the reference pressure 309, but the flow will drop all the way down to zero.
    Thus, since it is difficult to determine the flow in this type of control, the differential pressure gauge 310 is used to measure the pressure difference across the venturi 304. When the flow through the venturi is zero, the pressure difference across the tube will also be zero, while the pressure difference across the tube will be 76227; 2010-O8 ~ 26 10 15 20 25 30 13 greatest when the flow is greatest. By setting a limit value for the differential pressure gauge 310 to a level corresponding to a flow where the drill bit is considered clogged or about to become clogged, a warning signal can be generated when the limit value is reached, and the rock drilling device operator is alerted to the problem.
    According to the above, however, a problem with this type of solution is that the pressure switch is difficult to set (it is usually set with the help of adjusting screws), so it is set at the beginning of drilling or in the factory to a suitable value which is then maintained during drilling and thus does not change. as new drill rods are added to the drill string.
    Another problem with this type of solution is that the warning signal will be generated only when the pressure in the volume represented by hoses and drill rods after the venturi has risen to the reference pressure, since the flow through the venturi is required for this pressure build-up as long as the reference pressure level has not been reached. thus, there is still a purge air flow through the venturi tube even though the drill bit may be completely clogged. This pressure build-up can take different lengths of time, where the time will depend on the volume of the system downstream of the venturi, as well as the current pressure in the system when clogging occurs. The pressure build-up causes a delay before the warning signal is generated, with the result that the clogging / drilling situation has time to deteriorate further from the time clogging takes place until the warning signal is generated.
    The problem with the solution shown in Fig. 3 becomes even greater in the case where the compressor instead of being pressure controlled is regulated to a desired flow as above, as the compressor working pressure in such a solution is often lower (the actual required flow is often lower than the flow obtained at 76227; 2010 ~ O8 ~ 26 10 15 20 25 30 14 pressure control as above), and that the compressor flow is often lower (in the solution shown in Fig. 3, the compressor flow will be maximum as long as the pressure of the compressor tank is below the reference pressure), which means that the pressure build-up in the volume after the venturi will take even longer, with an even longer delay before the warning signal is generated as a result.
    The present invention solves this by determining a representation of a rate at which a pressure change occurs in the flushing medium circuit, this rate being used to determine if clogging of the drill bit is about to occur. The present invention is exemplified in Fig. 2. Fig. 2 shows the compressor 8 with inlet valve 202. The figure also shows a compressor tank / separator tank 203, to which a pressure sensor 207 is connected. The pressure sensor 207 is arranged to output signals to a control unit 208.
    The flow supplied from the compressor 8 to the tank 203 is then led via hoses 204 and the drill string 6 to the drill bit 3 for evacuating drill cuttings. Instead of controlling the compressor based on a reference pressure according to the solution shown in Fig. 3, the compressor is controlled according to the embodiment shown in Fig. 2 based on a reference flow 209.
    The reference flow 209 can e.g. obtained from another part of the rig control system, such as e.g. a control unit 18 which controls impact force, feed force and rotation etc. during drilling.
    The reference flow can e.g. is determined by calculations in the control unit 18, where the current hole depth, hole diameter, etc. can be used in the determination.
    The control unit 208 then regulates, based on the reference flow obtained, the flow of the compressor 8 as above by regulating the inlet valve 202, or by regulating the speed of the compressor, e.g. by regulation of 76227; 2010-08-26 10 l5 20 25 30 15 the speed of the internal combustion engine, and according to a further embodiment according to the above-described parallel application "Device and method for rock drilling". The control unit 208 constitutes a digital control unit, which thus receives a digital signal representing the reference flow. By regulating the compressor 8 based on a reference flow, it will thus always be known which flow is emitted by the compressor 8. This means that the pressure which arises in the purge air circuit will depend entirely on the current flow resistance, which, as described above, can vary e.g. with the number of drill rods.
    Instead of using a venturi tube as in the prior art in detecting stops in the purge air flow, according to the present invention only the pressure sensor 207 is used and the fact that the flow delivered by the compressor is known.
    According to the known continuity equation, at a given volume: _ __dV Ijlgg qi "quríifß d: (eq- 1) where: qm constitutes the flow from the compressor, which is known as above; gu constitutes the flow out through the drill bit; YY constitutes the air compression module. The compression module depends on the physical properties of the air, and can vary slightly depending on the type of compression process that takes place in the control volume (isothermal, adiabatic or a combination of the two). However, this source of error can with good approximation be assumed to be negligible. In cases where higher accuracy is required, the air temperature after the compressor can be determined, e.g. by means of a temperature sensor, this temperature being able to be used to correct for this variation. 76227; In a system according to Fig. 2, the volume V consists of the volume determined by the system between the compressor outlet up to the drill bit, i.e. mainly compressor tank as well as purge air hoses and drill string between tank and percussion. In practice, the volume V will vary slightly with the current oil volume in the compressor tank (this should normally be between a defined minimum and maximum value), as well as the number of drill rods and the purge air duct diameter in the drill rods.
    In one embodiment, therefore, the diameter of the purge air duct is fed into the control system of the rock drilling device so that this diameter can be taken into account. The control system can also be arranged to keep track of the number of drill rods in the drill string, whereby this change in volume can also be taken into account during ongoing drilling. It is also possible to use a level sensor in the separator tank to take into account varying oil levels.
    However, this volume change is not continuous, but occurs e.g. very slowly in terms of oil level, whereby the volume, if correction at all takes place, can take place at relatively long intervals, such as 1 time / hour or day. The volume change of the drill string also occurs when the number of drill rods changes, which occurs when the drilling is interrupted. , _, _ U _ dV .. _ Thus, no continuous calculation of íí-utforas when I use eq. l above. In one embodiment, the volume can also be considered to be constant throughout the drilling. Because the absolute largest part of the total volume V will be constituted by the compressor tank, variations as above can often be considered negligible with good approximation, and the volume V is considered constant. The largest volume in the system, apart from the compressor tank, consists of purge air hoses between the compressor and the drill string, and since these have a constant volume, they can advantageously be included in the 76227; 2010-08-26 10 15 20 25 l7 volume that is considered constant. In both cases above, eq. 1 above can be reduced to eq. 2 below: _ -Lili qín qut- "ße dt (ek-V '2) where V can possibly be changed by, for example, changing the number of drill rods as above, but thus from a computational point of view is considered constant.
    Unknown and eq. 2 thus consists of the flow out through the drill bit, qm, and ~ B »dr. An exemplary method 500 for determining flow change according to the present invention is shown in Fig. 5, and begins in step 501, where it is determined whether flow determination is to be performed, which t. ex. can be arranged to be performed on the compressor. .. _. dP and / or flushing is started. In step 502, ä-, i.e.
    In the rate (derivative) of the pressure change. The rate (derivative) of the pressure change is determined according to the present invention by means of successive measurements from the pressure sensor 207. This is exemplified in Fig. 4, which shows the variation of the pressure with time, measured with the pressure sensor 207.
    The calculation is exemplified for two arbitrary successive measuring points, where the pressure Pi and P¿ fl are obtained at. d. the times ti and thj. Derivatarl-åzkan saledes I .. P ~ P. is determined as -Ål-L, ie.
    - By performing the said @ 4_É Al determination with e.g. At intervals, the change in the derivative can be followed. Alternatively, another applicable method of determining the derivative may be used.
    Furthermore, as will be appreciated, eq. 2 that if the pressure derivative is greater than zero, the flow out through the drill bit is less than that of 76227; 2010-08-26 10 15 20 25 18 the amount of air supplied from the compressor, which indicates that the crown is being plugged. With knowledge of å you can thus constantly calculate how qm-qm relates, ie. how the flow out of the drill bit relates to the flow out of the dp compressor. As soon as Q-> 0 is qm <qm, ie. the flow out of If the drill bit is smaller than the flow out of the compressor, this is an indication that clogging is taking place. Many times minor blockages can occur which are then directly remedied solely by means of the flushing medium flow, whereby eggs fall again, which is why according to the present invention a limit value is used to determine whether severe clogging is taking place.
    Thus, if the pressure derivative gg: becomes too large, this means that the drill bit is being plugged again. In step 503, therefore, êåï is compared with a limit valueêêhhnü, and if âgï exceeds I I Z ._ .. AP. . . In step 504, a signal is generated to alert the drill rig operator and / or the rig rig control system that clogging is taking place. The operator and / or control system can then take appropriate measures to remedy problems with ongoing clogging, where methods are well described in the prior art, and which can be applied here. For example. percussion pressure and supply pressure can be reduced or completely switched off to allow the purge air system to Otherwise, the procedure returns to step 501.
    Thus, according to the present invention, flow changes (flow decreases) can be quickly determined by determining the 76227; 2010-08-26 10 15 20 EJ G1 19 speed at which the pressure in the system changes (ie the pressure derivatives change).
    The maximum pressure derivative (which occurs when the drill bit becomes completely clogged) depends on the amount of purge air supplied, ie. the compressor flow. For this reason, it may be advantageous n ,,,, AP. . that the branch value of the pressure derivative íš-knot depends on the current I compressor flow and / or the pressure on the high-pressure side of the compressor (such as, for example, the pressure determined by the pressure gauge 207).
    Thus, the above-mentioned limit value need not be fixed during the drilling process.
    Furthermore, the limit value can e.g. be set in such a way that it corresponds to a situation when the flow out through the flushing heels in the drill bit has dropped to e.g. 70% or 50% or other appropriate proportion of the flow from the compressor.
    The system can also be arranged to avoid "false" indications of clogging, e.g. in the case of very short-term clogging which is remedied only by means of the purge air flow. .. d In this case, the system can be arranged in such a way that 2% must exceed the limit value for a certain time, e.g. half a second, one second or at any other appropriate time interval.
    In an exemplary embodiment, the following terms are used to determine clogging: d 1,. _ l> - * q _ Flash * p _ derzvazfzve_ max, dt const where cäæf consists of a constant, q_P fi wh constitutes the desired 0 flow rate in f of maximum flow, and p_fk fl wmwe_nmx constitutes a maximum pressure increase rate which is considered to occur in 76227; 2010-08-26 10 15 20 25 20 system. The maximum pressure increase rate depends mainly on the maximum flow capacity of the compressor and the volume of the system.
    In the case where the solution shown in Fig. 2 operates in a pressure-controlled position, e.g. pga. that it has reached the maximum permissible working pressure, the flow monitoring described above is handled in a different way. In this operating mode, the compressor operates in a pressure-controlled manner, the system striving to maintain a constant secondary pressure, which means that% <= 0. Thus (I) it is sufficient to monitor the flow from the compressor because equation 2 in this case is reduced to% n = qm, where qm can be obtained directly from the compressor control. When qm falls below a given limit value, a warning signal is generated as above.
    Furthermore, the flow monitoring described above can be arranged to delay any suitable time period at e.g. system start-up to avoid the transients that often occur just when flushing is activated.
    In one embodiment, the second derivative is also considered in certain situations, such as e.g. at system startup.
    The second derivative describes the acceleration of the pressure increase, and can be used to determine whether an ongoing pressure increase e.g. is due to the fact that the system has just been started, and the pressure is thus on its way to a working pressure and does not increase due to. clogging. Even if the pressure increase occurs, and even the rate of pressure increase still increases, the rate at which the rate of pressure increase increases, i.e. acceleration, decrease, which can be used as an indication that clogging is not going on, at least as long as the acceleration is considered along with the pressure increase to ensure that pressure increase is still going on. 76227; 2010-08-26 21 Above, the present invention has been exemplified by a flow-controlled compressor. However, the compressor can also be controlled in another way, whereby the flow delivered by the compressor can be determined by means of a e.g. flow meters, e.g. on the high pressure side of the compressor. The invention can also be used in other types of drilling methods than exemplified above, such as e.g. at DTH (Down ~ The-Hole) drilling. 76227; 20lÛ ~ O8-26
    权利要求:
    Claims (17)
    [1]
    A method for determining a change in a flushing medium flow in a rock drilling device, wherein a compressor emits a flow of pressurized gas, said gas flow being at least partially used as flushing medium when drilling with a tool, wherein, during drilling, said flushing medium is led to said tool for flushing out drilling residues, the method comprising: ~ determining a rate of a pressure change for said flushing medium, and - generating a signal when said determined rate exceeds a first value.
    [2]
    The method of claim 1, wherein said signal is generated only when said determined speed has exceeded said first value for a first time.
    [3]
    A method according to claim 1 or 2, wherein said determining the speed of a pressure change is determined by determining a derivative of the pressure change of said flushing medium.
    [4]
    A method according to any one of the preceding claims, wherein said determining said speed for a pressure change is determined by means of successive pressure determinations, wherein said speed is determined according to :: ~, where AP constitutes Z the pressure difference between the pressure determinations and where At is the time between the pressure determinations.
    [5]
    A method according to any one of the preceding claims, wherein said compressor is controlled in such a way that a certain gas flow is emitted.
    [6]
    A method according to claim 5, wherein said compressor flow is controlled by speed control and / or control of the compressor inlet valve. 76227; 2010-08-26 lO 15 20 25 30 23
    [7]
    A method according to any one of the preceding claims, wherein said determining a rate of a pressure change for said purge medium is performed by means of a determination of a pressure change on said high pressure side of said compressor.
    [8]
    A method according to any one of the preceding claims, wherein said determining a rate of a pressure change for said flushing medium is performed by means of a determination of a pressure change at a position between said compressor and said tool.
    [9]
    A method according to any one of the preceding claims, wherein said determination of a speed is performed continuously or at certain intervals.
    [10]
    A method according to any one of the preceding claims, wherein, when drilling, said first value is determined at least in part based on the flow delivered by the compressor and / or a pressure on the high pressure side of the compressor.
    [11]
    11. ll. A method according to any one of the preceding claims, further comprising determining the flow delivered by the compressor by means of a flow meter.
    [12]
    A method according to any one of the preceding claims, wherein said signal is only generated when a second time has elapsed since drilling was started.
    [13]
    The method of any of the preceding claims, further comprising determining a representation of the acceleration (second derivative) for said pressure change of said flushing medium flow, said signal being generated only when said acceleration exceeds a second value.
    [14]
    A method according to any one of the preceding claims, wherein said determining a change of a flushing medium flow constitutes a determining of a decrease of said flushing medium flow delivered to said tool. 76227; 2010-08-26 10 15 24
    [15]
    A method according to any one of the preceding claims, wherein, when a maximum flushing medium pressure is reached, the flow from the compressor is determined, said signal being generated when said flow is less than a second value.
    [16]
    A system for determining a change of a flushing medium flow in a rock drilling device, wherein a compressor is arranged to deliver a flow of pressurized gas, said gas flow being at least partially arranged to be used as flushing medium when drilling with a tool, wherein, when drilling, said flushing medium is directed to said tool for flushing off drilling residues, characterized by: ~ first determining means for determining a speed for a pressure change for said flushing medium, and ~ signal generating means for generating a signal when said determined speed exceeds a first value.
    [17]
    Rock drilling device, characterized in that it comprises a system according to claim 16. 76227; 20l0 ~ 08-26
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    同族专利:
    公开号 | 公开日
    CN103069100A|2013-04-24|
    SE535421C2|2012-07-31|
    CN103069100B|2015-06-17|
    EP2609280A4|2017-08-09|
    EP2609280A1|2013-07-03|
    US9416605B2|2016-08-16|
    WO2012026874A1|2012-03-01|
    US20130167627A1|2013-07-04|
    AU2011293947B2|2015-01-29|
    AU2011293947A1|2013-02-21|
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    法律状态:
    优先权:
    申请号 | 申请日 | 专利标题
    SE1000870A|SE535421C2|2010-08-26|2010-08-26|Method and system for determining a change in a flushing medium flow and rock drilling device|SE1000870A| SE535421C2|2010-08-26|2010-08-26|Method and system for determining a change in a flushing medium flow and rock drilling device|
    PCT/SE2011/051026| WO2012026874A1|2010-08-26|2011-08-25|Method and system for determining a variation in a flushing medium flow and rock drilling apparatus|
    CN201180041453.3A| CN103069100B|2010-08-26|2011-08-25|Method and system for determining a variation in a flushing medium flow and rock drilling apparatus|
    EP11820259.7A| EP2609280A4|2010-08-26|2011-08-25|Method and system for determining a variation in a flushing medium flow and rock drilling apparatus|
    AU2011293947A| AU2011293947B2|2010-08-26|2011-08-25|Method and system for determining a variation in a flushing medium flow and rock drilling apparatus|
    US13/261,586| US9416605B2|2010-08-26|2011-08-25|Method and system for determining a variation in a flushing medium flow and rock drilling apparatus|
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