BACKGROUND OF THE INVENTION
Field of the Invention
[0001] The present invention relates to an operation-control device and an operation-control
method of vacuum pumps such as a scroll pump, a vane pump and the like, especially
to a case where plural set of vacuum pumps are provided.
Description of the Related Art
[0002] In conventional operation-control methods for vacuum pumps such as a scroll pump,
a vane pump and the like, a frequency control by an inverter is introduced and the
speed of an AC motor which drives a vacuum pump is controlled by using a signal of
a pressure-sensor detecting a pressure of gas inside a vacuum tank to be depressurized.
As for a pump load control by means of an inverter, a prior art, for instance, such
as
JP-A-H9-4591/1997 (hereafter, referred to as a patent document 1) or
EP 1314890 A2 has been known.
[0003] As shown in Fig. 5, in the patent document 1 is illustrated a control-step constitution,
wherein the speed of an AC motor 04, which drives a vacuum blower (vacuum pump) 03
connected to a vacuum tank 01, is controlled by a frequency converter (inverter) 05,
and the speed is increased when the operation differential pressure of the pump decreases
and demand power goes down, while the speed is decreased when the operation differential
pressure of the pump increases and demand power goes up; so that the input power poured
into the motor driving the pump is kept constant. Further, the pressure P inside the
vacuum tank 01 is detected for the estimation of vacuum condition.
[0004] In
EP 1314809 A2 the value of the electric current of the motor is monitored. However, the reduction
of the number of vacuum pumps in operation is triggered by a pressure detector.
[0005] In the conventional operation-control approaches for the vacuum pump as shown in
the patent document 1, a pressure (vacuum) sensor is used for estimating the vacuum
condition, since the vacuum condition in the tank 01 is detected as pressure P. In
case when dust and/or water droplets in the tank or the vacuum facility room adhere
to the probe of the sensor, it is afraid that the signals are not accurate and unexpected
failure may happen. Thus, special sensors of a dust-free type and/or a waterproof
type are required in order to prevent the invasion of dust and/or water droplet. Consequently,
there arises a problem of cost increase as to equipment and/or facility.
[0006] Furthermore, a speed control inverter always accompanies electronic noise which causes
undesirable problems to the surrounding electrical/electric equipment if it is nearby
the inverter.
[0007] On the other hand, in case where a constant vacuum condition is needed, for instance,
in case where a highly depressurized vacuum condition is required in a vacuum chamber
of semiconductor production devices, plural sets of vacuum pumps are provided. And
even when one of the pumps is out of service due to failure or maintenance and exhaust
ability is lessoned, the remaining pumps hold the predetermined required vacuum condition.
[0008] However, driving plural sets of pumps results in an increase of power consumption
and maintenance costs. Furthermore, providing plural pumps may increase failure frequency
of the pumps, maintenance frequency of the pumps along with affiliated facility and
man-hours for repairing.
SUMMARY OF THE INVENTION
[0009] In view of the above-stated background, the present invention is aiming at: eliminating
the difficulties in such a case of introduction of vacuum sensors and/or inverter
speed control; realizing the operation of plural vacuum pumps wherein the increase
of facility costs is restrained, the maintenance frequency is reduced and the man-hour
of repair work is lessened; and providing an operation control device and an operation
control method which are compatible with the just-stated aims.
[0010] In order to resolve the problems mentioned above, the present invention provides
an operation control device of plural vacuum pumps for depressurizing a gas inside
at least one tank and/or vacuum facility room and so on, including: a current detecting
means which detects a current flowing in a motor that drives the vacuum pumps; and
a control means which reduces the number of the vacuum pumps actually under operation,
while judging whether a target vacuum or substantially vacuum condition is reached,
based on a situation that a current value detected by the current detection means
converges within a predetermined range.
[0011] According to the present invention, the current flowing in the motor is detected,
and it is judged that a target vacuum or substantially target vacuum condition is
realized when the current value converges within a predetermined range. Therefore,
it is not necessary to provide with vacuum sensors for pressure detection of a vacuum
tank as conventionally used, so that equipment costs can be restrained and a remarkable
cost effectiveness can be obtained, especially in case where special sensors of a
dust-free type and/or a waterproof type are required, depending on the service condition
as to a vacuum tank or a vacuum facility room.
[0012] Since the gas to be exhausted is reduced when a target vacuum or substantially target
vacuum condition is realized, it is possible to hold the vacuum condition or to reach
the target vacuum condition without operation of an unnecessary pump. Therefore, it
becomes possible to decrease the number of plural working vacuum pumps, to reduce
the amount of power consumption as a result and to prolong maintenance intervals by
stopping the operation of an unnecessary pump. In the control for operation and start/stop
of the pumps, speed control equipment such as inverters and the like is not provided.
Therefore, undesirable effect due to inverters on surrounding equipment is avoidable.
[0013] According to another constitution of the present invention, the control means of
the operation control device further includes a vacuum-degree-estimation means to
judge that a threshold criterion value is reached when a current value of the motor
under watch reaches the predetermined range, the threshold criterion value being predetermined
in advance of a target-vacuum value and to conclude that said target-vacuum value
is reached in case when the current value stays within the predetermined range for
a predetermined span of time after the threshold criterion value is reached; in which
when the vacuum-degree-estimation means concludes that the threshold criterion value
or the target-vacuum value within the predetermined range is reached, the number of
the pumps under operation is reduced.
[0014] The another constitution of the above mentioned makes it possible to decrease the
number of plural working vacuum pumps and to reduce the amount of power consumption
as a result, because the target vacuum can be reached without large current after
the depressurized pressure reaches the threshold criterion value. In addition, it
is made possible that the number of pumps and the amount of power consumption are
reduced after surely estimating that the target vacuum (negative pressure) is reached
when the detected current stays for a predetermined span of time in the predetermined
range.
[0015] According to another aspect of the present invention, the target-vacuum value within
the predetermined range is reset at a lower value as the operation hours of the vacuum
pumps are prolonged.
[0016] By the above constitution, more accurate judgment on a vacuum-degree-completion is
carried out, while the operation hours are taken into consideration. Here, the consideration
is given in such a manner that the aforementioned predetermined current range, whereby
the threshold-criterion value is regarded as reached, is lowered in connection with
operation hours. In addition, the reason of this lowering is that a load demand for
the vacuum pumps decreases gradually in proportion to the accumulated operation hours
because of a running-in effect as to rotating and/or sliding wear-elements.
[0017] Another aspect of the present invention is characterized in that the operation control
device includes a pump operation control means, which designates one of the plural
pumps as a pump under watch, stops at least one of the pumps other than the pump under
watch when the vacuum-degree-estimation means concludes, based on a current value
of the motor driving the pump under watch, that the threshold criterion value or the
target-vacuum value within the predetermined range is reached and shifts the pump
under watch evenly one by one among the whole pumps.
[0018] According to a method of the present invention of controlling plural vacuum pumps,
the method includes the steps of designating a pump under watch, stopping the pumps
other than the pump under watch and shifting the pump under watch one by one among
the whole pumps; thereby such operation manner can be evaded that a specific pump
is always working, the other pumps are kept under suspension, and the operation unevenness
among the plural pumps is incurred as a result. Therefore, plural pumps are evenly
employed and maintenance work for each pump is equalized. Thus, the increase in efficiency
of maintenance work can be promoted.
[0019] Another constitution of the present invention is characterized in that, in a case
where any one of the vacuum pumps is unable or difficult to be operated, the operation
of the pump unable or difficult to be operated is skipped and the other next pump
is designated as a pump under watch.
[0020] The above constitution makes it possible to prevent operation unevenness among the
plural sets of the vacuum pumps, since plural pumps are evenly employed and the operation
hours of each pump are equalized.
[0021] Another constitution of the present invention relates to an operation control method
for plural vacuum pumps for depressurizing a gas inside at least one tank and/or chamber
including the steps of: detecting a current flowing in a motor that drives the vacuum
pumps; and reducing the number of the vacuum pumps actually under operation, while
judging whether a target vacuum and/or substantially vacuum condition is reached,
based on the situation that a current value detected by the current detection means
converges within a predetermined range.
[0022] According to the above constitution, the current to each motor which drives each
corresponding vacuum pump is detected and it is judged that the target-vacuum or the
substantial target-vacuum is realized when the current value converges within a predetermined
range, resulting in that conventionally applied vacuum sensors for pressure detection
of a vacuum tank or a vacuum facility room can be omitted, and the above constitution
also makes it possible to restrain equipment costs and brings remarkable cost effectiveness
especially in case in which special sensors of a dust-free type and/or a waterproof
type are required, depending on the service condition as to a vacuum tank or a vacuum
facility room.
[0023] Moreover, the above constitution makes it possible to decrease the number of plural
working vacuum pumps, to reduce the amount of power consumption as a result and to
prolong maintenance intervals by stopping the operation of an unnecessary pump; since
the gas to be exhausted is reduced when a target vacuum or substantially target vacuum
condition is realized, it is possible to hold the vacuum condition or to reach the
target vacuum condition without operation of an unnecessary pump. Still furthermore,
in the control for operation and start/stop of the pumps, speed control equipment
such as inverters and the like is not necessary. Therefore, undesirable effects due
to inverters on surrounding equipment are avoidable.
[0024] In connection with the above, still another constitution of the present invention
can be given: an operation control method including the steps of designating one of
the plural pumps as a pump under watch; judging that a threshold criterion value is
reached when a current value of the motor under watch reaches a predetermined range,
the threshold criterion value being predetermined in advance of a target-vacuum value;
concluding that said target-vacuum value is reached in case when the current value
stays within the predetermined range for a predetermined span of time after the threshold
criterion value is reached; stopping at least one pump other than the pump under watch
when it is concluded that the threshold criterion value and/or said target-vacuum
value within the predetermined range is reached, based on a current value of the motor
driving the pump under watch; shifting the pump under watch evenly to the other next
pump one by one among the whole pumps.
[0025] According to the above described invention, it is made possible to decrease the number
of plural working vacuum pumps and to reduce a power consumption as a result, because
the target vacuum can be reached without large current after the depressurized pressure
reaches the threshold criterion value. In addition, the number of pumps and the amount
of the power consumption are reduced after surely estimating that the target vacuum
(negative pressure) is realized when the detected current stays for a predetermined
span of time in the predetermined range.
[0026] Moreover, according to the above constitution, is evaded disadvantage that the operation
unevenness among the plural pumps is incurred as a result of working a specific pump
at all the times and keeping the other pumps under suspension. Therefore, plural pumps
are evenly employed and maintenance work for each pump is equalized. Thus, the increase
in efficiency of maintenance work can be promoted.
[0027] The present invention can provide an operation control device and operation method
thereof so as to eliminate the difficulties in such a case of introduction of vacuum
sensors and/or inverter. In addition, by the operation of plural vacuum pumps of the
present invention, the increase of facility costs is restrained, the maintenance frequency
is reduced and the man-hour of repair work is lessened.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] The present invention will now be described in greater detail with reference to the
preferred embodiments of the invention and the accompanying drawings, wherein:
FIG. 1 shows a whole constitution of the invention;
FIG.2 is a figure sowing power (a current value) characteristic of a vacuum pump;
FIG.3 illustrates a time chart as to an exemplary embodiment of the invention;
FIG.4 illustrates a control flowchart as to an exemplary embodiment of the invention;
and
FIG.5 illustrates a prior art.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0029] Hereafter, the present invention will be described in detail with reference to the
embodiments shown in the figures. However, the dimensions, materials, shape, the relative
placement and so on of a component described in these embodiments shall be only for
explanation and shall not be construed as limiting the scope of the invention thereto,
unless any specific mention is made of.
[0030] FIG. 1 shows a whole constitution of the invention, wherein a vacuum tank 1 is depressurized
by three vacuum pumps P
A, P
B and P
C. The vacuum pumps P
A, P
B and P
C are driven by motors M
A, M
B and M
C, respectively. There are placed electromagnetic open/close valves V
A, V
B and V
C between the vacuum tank 1 and each of the vacuum pumps P
A, P
B and P
C, respectively. Each of the vacuum pumps P
A, P
B and P
C is of a rotary displacement (volumetric) type such as of a scroll type or of a vane
type, etc.
[0031] Each of the motors M
A, M
B and M
C is supplied with electricity from a power source 3. Since the speed control of each
of the motors M
A, M
B and M
C is not performed, an inverter or the like is not prepared. Incidentally, each of
the motors needs only to be an electric motor and the present invention is applicable
to both AC motor and DC motor. In addition, a current-detecting means 5 detects the
supplied current to each motor.
[0032] A control means 7 controls the operation and start/stop of the vacuum pumps P
A , P
B and P
C. The control means 7 includes a vacuum-degree-estimation means 9 to judge whether
the current signal from the current-detecting means 5 reaches a threshold criterion
value S which is set beforehand a target-vacuum value within a predetermined range
and to judge whether the current signal from the current-detecting means 5 converges
to the target vacuum (negative pressure) value with a predetermined span of time after
the current signal reaches a threshold criterion value S, and a pump operation control
means 11 to reduce the number of the pumps under operation when the vacuum-degree-estimation
means 9 concludes that the threshold criterion value S or the target-vacuum value
within a predetermined range is reached.
[0033] In case of the pump of a rotary displacement (volumetric) type such as of a scroll
type or of a vane type, a power (current value) characteristic curve is shown as such
a curve as in Fig. 2, wherein the curve includes a flat straight part and a mountain-shaped
part, thereby the flat straight part corresponds to the current convergence by way
of vacuum accomplishment and the mountain-shaped part means a large variation of the
current.
[0034] Just after a commencement of depressurization of the vacuum tank 1, power (current
value) is needed since the pumps have to compress and exhaust a high-pressure gas.
In due course of depressurization process, the gas to be exhausted disappears substantially.
Therefore, the required power (current value) is lessened, while a negative pressure
value in the vacuum tank converges to a substantially constant value less than or
equal to 10
2 Pa to 10
3 Pa.
[0035] By means of the aforementioned power (current) characteristics in such that the current
value converges to a constant value P in connection with the depressurization process,
the vacuum-degree-estimation means 9 judges whether the detected current reaches the
aforementioned predetermined range from the constant value P minus a to the constant
value P plus a, where a is allowance made for the fluctuation of measured values.
The vacuum-degree-estimation means 9 also estimates the time when the detected current
enters the range, namely, the time when the current reaches the aforementioned, predetermined-threshold-criterion
value S. Further, the vacuum-degree-estimation means 9 concludes that the target vacuum
(negative pressure) is completed, if the current is held within the range for a predetermined
duration of time, for instance, several minutes.
[0036] On the other hand, the above constant value P is scheduled to be reset at a lower
value as the operation hours of the vacuum pump P
A, P
B or P
C is accumulated. That is, the setting value P at the time of commissioning of the
pumps is reduced to a value kP (P multiplied by a coefficient k) in such a manner
that kP=0.9P, kP=0.8P and so on, where k is a parameter dependent of the operation
hours of the vacuum pump P
A, P
B or P
C and k has a decreasing tendency in relation to increased operation hours.
[0037] More specifically, since a load demand for the vacuum pumps decreases gradually in
proportion to the accumulated operation hours because of a running-in effect r as
to rotating and/or sliding wear-elements, a consideration for operation hours can
give more accurate judgment on a vacuum-degree-completion. In addition, the consideration
is given in such a manner that the aforementioned predetermined current range, whereby
the threshold-criterion value S is regarded as reached, is lowered in connection with
operation hours.
[0038] Judgment on whether the depressurized pressure reaches the threshold criterion value
S, which is set beforehand the target-vacuum value, or the target-vacuum value is
made by detecting the current to each of the motors M
A, M
B and M
C which drives each of the vacuum pumps P
A, P
B and P
C respectively. Therefore, the present invention can do without conventionally applied
vacuum sensors for pressure detection of a vacuum tank and the present invention makes
it possible to restrain equipment costs and brings a remarkable cost effectiveness
especially in case in which special sensors of a dust-free type and/or a waterproof
type are required, depending on the service condition as to a vacuum tank or a vacuum
facility room.
[0039] When the depressurized pressure reaches the threshold criterion value S, which is
set beforehand the target-vacuum value, the target-vacuum can be realized without
operation of an unnecessary pump because the gas to be exhausted is reduced. When
the target vacuum has been realized, the vacuum state can be held without operation
of an unnecessary pump. Accordingly, it becomes possible to decrease the number of
plural working vacuum pumps, to reduce the amount of power consumption as a result
and to prolong maintenance intervals by stopping the operation of an unnecessary pump.
In the control for operation and start/stop of the pumps, speed control equipment
such as inverters and the like is not provided. Therefore, undesirable effects on
surrounding equipment due to inverters are avoidable.
[0040] In succession, with reference to the time chart of Fig. 3 and the flowchart of Fig.
4, the explanation will be given about how the pump operation control means 11 reduces
the number of the pumps under operation when the vacuum-degree-estimation means 9
concludes that the depressurized pressure reaches the threshold criterion value S.
[0041] As shown in Fig. 4, all the vacuum pumps P
A, P
B and P
C are under operation at the beginning (S1) and the vacuum pump P
A is chosen as a pump to be watched, and the current I
A thereof is monitored (S2). Whether the current I
A is within a range of P-α ≦I
A≦P+α is judged (S3) and, in case in which the judgment is YES (affirmative), whether
the duration thereof is not less than a predetermined time span t
0 is further judged (S4). If the judgment is YES (affirmative) in succession, then
the target-vacuum is regarded as realized and the vacuum pumps P
B and P
C are stopped, while only the operation of the pump P
A is continued (S5).
[0042] It can be allowed to stop the vacuum pumps P
B and P
C, without the judgment on whether the duration of the condition S4 is not less than
a predetermined time span t
0, when it is judged whether the current I
A is within a range of P-a ≦ I
A ≦ P+a (S3) and the judgment is YES (affirmative), namely, when the depressurized
pressure reaches the threshold criterion value S.
[0043] And while the monitoring of the current I
A is continued, whether I
A exceeds P+ α because of the deterioration of the vacuum state is judged (S6). If
the I
A becomes greater than P + α, then all the vacuum pumps P
A, P
B and P
C are operated again (S7). In succession, the pump to be monitored is shifted to the
vacuum pumps P
B (S8) and the vacuum state is watched in such a manner that the current I
B for the pump P
B is watched by the same approach as the above-mentioned vacuum pump P
A is watched. In case in which the vacuum pump P
B is designated as the pump to be monitored, the pumps to be stopped are shifted to
the pumps P
A and P
C and the only pump to be operated is shifted to the pump P
B (S9).
[0044] In the next stage, the pump to be watched is shifted to the vacuum pump P
C (S10), and the vacuum state is monitored watched in the same approach as the case
where a vacuum pump P
A is used as a pump to be watched. In case where the vacuum pump P
C is designated as the pump to be watched, the pumps to be stopped are shifted to the
pumps P
A and P
B and the only pump to be operated is shifted to the pump P
C (S11).
[0045] Therefore, as shown in Fig. 4, a pump operation control means 11 is constituted so
that the control means 11 shifts a control step by a control step in such a manner
that a control step A in the case where the vacuum pump P
A is used as a pump to be watched, a control step B in the case where the vacuum pump
P
B is used as a pump to be watched, and a control step C in the case where the vacuum
pump P
C is used as a pump to be watched.
[0046] A time chart of Fig. 3 shows the situation of the shifting, namely, a shift-circulation.
After the pump P
A is started-up as a first pump to be operated, the pumps P
B and P
C are started with predetermined time-delays. And all the pumps are placed under operation.
The time delays are provided in order to evade a large load, that is, an over-current
due to the simultaneous starting of plural pumps.
[0047] A mark L in Fig. 3 means a point of time when the threshold criterion value S or
the target-vacuum value is reached and the pumps other than the pump under watch are
stopped. A mark M means a point of time when a detected current value goes out of
the aforementioned predetermined range and, therefore, the pumps under suspension
are now be restarted. The control action at the marks L or M is repeated also in case
when the pump under watch is the pump P
B or P
C.
[0048] Moreover, in a case where any one of the vacuum pumps P
A ,P
B and P
C is unable or difficult to be operated, the operation of the pump unable or difficult
to be operated is skipped and the other next pump is designated as a pump to be watched.
For instance, when the pump P
B is out of order or under maintenance, the pump to be monitored is shifted from the
pump P
A to the pump P
C.
[0049] Furthermore, the electromagnetic open/close valves V
A, V
B and V
C are provided so as to hinder high pressure gas from flowing-back inside the vacuum
tank by the vacuum pumps P
A, P
B and P
C. The valve V
A , V
B or V
C is opened respectively after the vacuum pumps P
A , P
B or P
C starts running.
[0050] In addition, it is not always necessary to stop simultaneously all the active pumps
other than the pump under watch. It can be allowed to stop the pumps one by one so
as to evade rapid change in pump-loads. Also, depending on the vacuum-degree requirement,
it can be allowed to stop some pumps out of all the pumps other than the pump under
watch.
[0051] In the above description on the embodiments, explanation has been given based on
an example of three pumps. It goes without saying that the explanation stands in case
of plural pumps such as a case of two pumps, four pumps and/or more pumps.
[0052] As mentioned above, by a method of controlling plural vacuum pumps, including the
steps of designating a pump under watch, stopping the pumps other than the pump under
watch and shifting the pump under watch one by one among the whole pumps, can be evaded
a disadvantage that the operation unevenness among the plural pumps is incurred as
a result of working a specific pump all the time and keeping the other pumps under
suspension. Therefore, plural pumps are evenly employed and maintenance work for each
pump is equalized.
Thus, the increase in efficiency of maintenance work can be promoted.
[0053] The present invention eliminates the difficulties in such a case of introduction
of vacuum sensors and/or inverter control. In addition, the present invention realizes
the operation of plural vacuum pumps wherein the increase of facility costs is restrained,
the maintenance frequency is reduced and the man-hour of repair work is lessened.
As a conclusion, the present invention can be applicable to operation control devices
and operation methods for plural vacuum pumps.
1. An operation control device of plural vacuum pumps (P
A, P
B, P
C) for depressurizing gas inside at least one tank and/or chamber (1), comprising:
a current detecting means (5) which detects a current flowing in a motor (MA, MB, MC) that drives the vacuum pumps (PA, PB, PC); and characterized in that it comprises:
a control means (7) which reduces the number of the vacuum pumps under operation by
judging that a target vacuum and/or substantially vacuum condition is reached when
a current value detected by said current detecting means (5) converges within a predetermined
range.
2. The operation control device of claim 1, wherein the control means (7) further comprises a vacuum-degree-estimation means
(9) to judge that a threshold criterion value is reached when a current value of the
motor under watch reaches the predetermined range, the threshold criterion value being
predetermined in advance of a target-vacuum value and to conclude that said target-vacuum
value is reached in case when the current value stays within the predetermined range
for a predetermined span of time after the threshold criterion value is reached; wherein
when the vacuum-degree-estimation means concludes that the threshold criterion value
or the target-vacuum value within the predetermined range is reached, the number of
the pumps under operation is reduced.
3. The operation control device of claim 1, wherein the target-vacuum value within the predetermined range is reset at a lower
value as an operation hours of the vacuum pumps is accumulated.
4. The operation control device of claim 2, wherein the control means (7) further comprises pump operation control means (11);
which designates one of the plural pumps as a pump under watch, stops at least one
pump other than the pump under watch when said vacuum-degree-estimation means concludes,
based on a current value of the motor driving the pump under watch, that said threshold
criterion value or said target-vacuum value within the predetermined range is reached
and shifts the pump under watch evenly one by one among the whole pumps.
5. The operation control device of claim 4, wherein in a case where any one of the vacuum pumps is unable or difficult to be
operated, the operation of the pump unable or difficult to be operated is skipped
and the other next pump is designated as a pump under watch.
6. An operation control method for plural vacuum pumps (P
A, P
B, P
C) for depressurizing a gas inside at least one tank and/or chamber (1), comprising
the step of:
detecting a current flowing into a motor (MA, MB, MC) that drives the vacuum pumps (PA, PB, PC); and characterized by comprising the step of:
reducing the number of the vacuum pumps under operation by judging that a target vacuum
and/or substantially vacuum condition is reached when a current value detected by
said current detecting means (5) converges within a predetermined range.
7. The operation control method of claim 6, further comprising the steps of: designating one of the plural pumps as a pump under
watch; judging that a threshold criterion value is reached when a current value of
the motor under watch reaches the predetermined range, the threshold criterion value
being predetermined in advance of a target-vacuum value; concluding that said target-vacuum
value is reached in case when the current value stays within the predetermined range
for a predetermined span of time after the threshold criterion value is reached; stopping
at least one pump other than the pump under watch when it is concluded that said threshold
criterion value and/or said target-vacuum value within the predetermined range is
reached, based on a current value of the motor driving the pump under watch; and shifting
said pump under watch evenly to the other next pump one by one among the whole pumps.
1. Betriebssteuerungsvorrichtung einer Vielzahl von Vakuumpumpen (P
A, P
B, P
C) zum Druckabbau von Gas innerhalb mindestens eines/r Behälters und/oder Kammer (1),
umfassend:
eine Stromerfassungseinheit (5), welche einen in einem Motor (MA, MB, MC) fließenden Strom erfasst, welcher die Vakuumpumpen (PA, PB, PC) antreibt, und dadurch gekennzeichnet, das sie umfasst:
eine Steuerungseinheit (7), welche die Anzahl der Vakuumpumpen im Betrieb verringert,
indem beurteilt wird, dass ein Zielvakuum und/oder ein weitgehender Vakuumzustand
erreicht ist, wenn ein durch die Stromerfassungseinheit (5) erfasster Stromwert innerhalb
eines vorbestimmten Bereichs konvergiert.
2. Betriebssteuerungsvorrichtung nach Anspruch 1, wobei die Steuereinheit (7) weiterhin
eine Vakuumgradabschätzeinheit (9) zur Beurteilung, dass ein Schwellwertkriterium
erreicht ist, wenn ein Stromwert des beobachteten Motors den vorbestimmten Bereich
erreicht, umfasst, wobei das Schwellwertkriterium vor einem Zielvakuumwert vorbestimmt
wird, und zur Folgerung, dass der Zielvakuumwert erreicht wird, für den Fall, dass
der Stromwert für eine vorbestimmte Zeitspanne nach Erreichen des Schwellwertkriteriums
innerhalb des vorbestimmten Bereichs bleibt; wobei, wenn die Vakuumgradabschätzeinheit
folgert, dass das Schwellwertkriterium oder der Zielvakuumwert innerhalb des vorbestimmten
Bereichs erreicht ist, die Zahl der Pumpen und der Betrieb verringert wird.
3. Betriebssteuerungsvorrichtung nach Anspruch 1, wobei der Zielvakuumwert innerhalb
des vorbestimmten Bereichs auf einen niedrigeren Wert zurückgesetzt wird, wenn die
Betriebsstunden der Vakuumpumpen sich angehäuft haben.
4. Betriebssteuerungsvorrichtung nach Anspruch 2, wobei die Steuerungseinheit (7) weiterhin
eine Pumpenbetriebssteuerungseinheit (11) aufweist, die eine der Vielzahl von Pumpen
als zu beobachtende Pumpe ausweist, mindestens eine andere Pumpe als die Pumpe unter
Beobachtung stoppt, wenn die Vakuumgradabschätzeinheit folgert, basierend auf einem
Stromwert des Motors, welcher die Pumpe unter Beobachtung antreibt, dass das Schwellwertkriteriums
oder der Zielvakuumwert innerhalb des vorbestimmten Bereichs erreicht ist, und die
Pumpe unter Beobachtung gleichmäßig eine nach der anderen unter den gesamten Pumpen
verschiebt.
5. Betriebssteuerungsvorrichtung nach Anspruch 4, wobei, wenn eine der Vakuumpumpen nicht
oder schwer zu betreiben ist, der Betrieb der schwer oder schwierig zu betreibenden
Pumpe ausgelassen wird und die andere nächste Pumpe als Pumpe unter Beobachtung ausgewiesen
wird.
6. Betriebssteuerungsverfahren für eine Vielzahl von Vakuumpumpen (P
A, P
B, P
C,) zum Druckablassen eines Gases innerhalb mindestens eines Behälters und/oder einer
Kammer (1) mit den folgenden Schritten:
Erfassen eines in einen Motor (MA, MB, MC) fließenden Stroms, der die Vakuumpumpen (PA, PB, PC, ) antreibt; dadurch gekennzeichnet, dass es den Schritt aufweist:
Verringern der Anzahl der Vakuumpumpen unter Betrieb durch Beurteilung, dass ein Zielvakuum
und/oder ein weitgehender Vakuumzustand erreicht ist, wenn ein durch die Stromerfassungseinheit
(5) erfasster Stromwert innerhalb eines vorbestimmten Bereichs konvergiert.
7. Betriebssteuerungsverfahren nach Anspruch 6, weiterhin umfassend die Schritte:
Ausweisen einer der Vielzahl von Pumpen als Pumpe unter Beobachtung; Beurteilen, dass
ein Schwellwertkriterium erreicht ist, wenn ein Stromwert des Motors unter Beobachtung
den vorbestimmten Bereich erreicht, wobei das Schwellwertkriterium im Voraus von einem
Zielvakuumwert vorbestimmt wird; Folgern, dass der Zielvakuumwert erreicht ist, wenn
der Stromwert für eine vorbestimmte Zeitspanne nach Erreichen des Schwellwertkriteriums
in dem vorbestimmten Bereich bleibt; Stoppen mindestens einer anderen Pumpe als der
Pumpe unter Beobachtung, wenn gefolgert wird, dass das Schwellwertkriterium und/oder
der Zielvakuumwert innerhalb des vorbestimmten Bereichs erreicht ist, basierend auf
einem Stromwert des Motors, welcher die Pumpe unter Beobachtung antreibt; und Verschieben
der Pumpe unter Beobachtung gleichförmig zu der anderen nächsten Pumpe nacheinander
unter den gesamten Pumpen.
1. Dispositif de commande de fonctionnement de plusieurs pompes à vide (P
A, P
B, P
C) afin de dépressuriser un gaz à l'intérieur d'au moins un réservoir et/ou une chambre
(1), comprenant:
un moyen de détection de courant (5) qui détecte un courant circulant dans un moteur
(MA, MB, MC) qui actionne les pompes à vide (PA, PB, PC) ; et caractérisé en ce qu'il comprend:
des moyens de commande (7) qui réduisent le nombre des pompes à vide en fonctionnement
en jugeant qu'une condition cible de vide et/ou de presque vide est atteinte lorsqu'une
valeur de courant détectée par ledit moyen de détection de courant (5) converge à
l'intérieur d'une plage prédéterminée.
2. Dispositif de commande de fonctionnement selon la revendication 1, dans lequel les
moyens de commande (7) comprennent en outre un moyen d'estimation de degré de vide
(9) servant à juger qu'une valeur de critère de seuil est atteinte lorsqu'une valeur
de courant du moteur sous surveillance atteint la plage prédéterminée, la valeur de
critère de seuil étant prédéterminée à l'avance comme une valeur de vide cible, et
à conclure que ladite valeur de vide cible est atteinte dans le cas où la valeur de
courant reste à l'intérieur de la plage prédéterminée pendant une période de temps
prédéterminée après que la valeur de critère de seuil ait été atteinte; dans lequel
lorsque le moyen d'estimation de degré de vide conclut que la valeur de critère de
seuil ou la valeur de vide cible à l'intérieur de la plage prédéterminée est atteinte,
le nombre des pompes en fonctionnement est réduit.
3. Dispositif de commande de fonctionnement selon la revendication 1, dans lequel la
valeur de vide cible à l'intérieur de la plage prédéterminée est réinitialisée à une
valeur inférieure lorsque des heures de fonctionnement des pompes à vide sont accumulées.
4. Dispositif de commande de fonctionnement selon la revendication 2, dans lequel les
moyens de commande (7) comprennent en outre des moyens de commande de fonctionnement
de pompe (11); qui désignent une parmi la pluralité de pompes comme étant la pompe
sous surveillance, qui arrêtent au moins une pompe autre que la pompe sous surveillance
lorsque ledit moyen d'estimation de degré de vide conclut, sur la base d'une valeur
de courant du moteur qui actionne la pompe sous surveillance, que ladite valeur de
critère de seuil ou ladite valeur de vide cible à l'intérieur de la plage prédéterminée
est atteinte, et qui placent successivement sous surveillance une par une de façon
uniforme chaque autre pompe suivante de l'ensemble des pompes.
5. Dispositif de commande de fonctionnement selon la revendication 4, dans lequel, dans
un cas où l'une quelconque des pompes à vide est impossible ou difficile à mettre
en marche, la mise en marche de la pompe impossible ou difficile à mettre en marche
est sautée et l'autre pompe suivante est désignée comme étant la pompe sous surveillance.
6. Procédé de commande de fonctionnement pour plusieurs pompes à vide (P
A, P
B, Pc) afin de dépressuriser un gaz à l'intérieur d'au moins un réservoir et/ou une
chambre (1), comprenant l'étape suivante:
détecter un courant circulant dans un moteur (MA, MB, MC) qui actionne les pompes à vide (PA, PB, PC); et caractérisé en ce qu'il comprend l'étape suivante:
réduire le nombre des pompes à vide en fonctionnement en jugeant qu'une condition
cible de vide et/ou de presque vide est atteinte lorsqu'une valeur de courant détectée
par ledit moyen de détection de courant (5) converge à l'intérieur d'une plage prédéterminée.
7. Procédé de commande de fonctionnement selon la revendication 6, comprenant en outre
les étapes suivantes:
désigner une parmi la pluralité de pompes comme étant la pompe sous surveillance;
juger qu'une valeur de critère de seuil est atteinte lorsqu'une valeur de courant
du moteur sous surveillance atteint la plage prédéterminée, la valeur de critère de
seuil étant prédéterminée à l'avance comme une valeur de vide cible;
conclure que ladite valeur de vide cible est atteinte dans le cas où la valeur de
courant reste à l'intérieur de la plage prédéterminée pendant une période de temps
prédéterminée après que la valeur de critère de seuil ait été atteinte;
arrêter au moins une pompe autre que la pompe sous surveillance lorsqu'il est conclu
que ladite valeur de critère de seuil et/ou ladite valeur de vide cible à l'intérieur
de la plage prédéterminée est atteinte, sur la base d'une valeur de courant du moteur
qui actionne la pompe sous surveillance; et
placer successivement sous surveillance une par une de façon uniforme chaque autre
pompe suivante de l'ensemble des pompes.