Method for determining a distance-related running frictional resistance of the belt conveyor system
The present invention relates to a method for determining a section-related running friction resistance of the belt conveyor system that is in operation. The method comprises at least the following steps: A) dividing the conveyor section of the belt conveyor system into “m” system-specific segments, B) input of constant data at least with regard to the transport length of the belt conveyor system, the length of the segments and the incline or decline per segment into the evaluation device, C) continuous recording of varying data at least with regard to the current conveyor belt speed and the drive power or the drive torque, D) specification of determination data comprising at least a current material section mass and a segment-specific belt loading q m of the entire belt conveyor system based on the is measured material mass flow at the measurement point, E) storage of the completely recorded varying data and the determination data in the evaluation device after each passage through a defined conveyor belt portion of the conveyor belt, wherein each passage is numbered with a consecutive index “j”, and F) calculation of the load-dependent running friction resistance for each segment and the idling power of the belt conveyor system by the evaluation device by means of a system of equations using the constant data, the varying data and the determination data.
1 . A method for determining a section-related running friction resistance (f i ) of a belt conveyor system that is in operation, the method including:
dividing a conveyor section of the belt conveyor system into “m” system-specific segments (L 1 , . . . , L m );
inputting of constant data at least with regard to a transport length of the belt conveyor system, a segment length of the system-specific segments (L 1 , . . . , L m ) and an incline or a decline per system-specific segment (L 1 , . . . , L m ) into an evaluation device;
continuous recording of varying data at least with regard to a current conveyor belt speed (V B ), a material mass flow (Q S ) and a drive power (P) or a drive torque;
specifying of determination data comprising at least a current material section mass (M 1 , . . . , M m ) and a segment-specific belt loading (q 1 , . . . , q m ) of the belt conveyor system based on the material mass flow (Q S ) at a measurement point;
storing of the varying data and the determination data in the evaluation device after each passage through a defined conveyor belt portion (ΔL) of a conveyor belt in the conveyor belt system, wherein each passage is numbered with a consecutive index “j”; and
calculating of a load-dependent running friction resistance (f i,j , . . . , f m,j ) for each of the system-specific segments (L 1 , . . . , L m ) and an idling power (P o ) of the belt conveyor system by the evaluation device by means of a system of equations using the constant data, the varying data and the determination data.
2 . The method according to claim 1 ,
characterized in that
the system of equations for determining the load-dependent running friction resistance (f) for last “n” complete belt revolutions is generated, wherein the system of equations comprises corresponding data with regard to a belt loading matrix (q) and a total movement resistance force vector (ΔR), as follows:
q×f=ΔR.
3 . The method according to claim 1 ,
characterized in that
a current lifting power (P H,j ) of a total transported material flow mass of the belt conveyor system is additionally determined as the varying data as a sum of current lifting powers (P H,i,j ) of all the system-specific segments and is stored in the evaluation device.
4 . The method according to claim 1 ,
characterized in that
the segment-specific belt loading and a carrier roller gravity (q 0,i ) per segment length (L 1 , . . . , L m ) are also entered into the evaluation device as the constant data.
5 . The method according to claim 2 ,
characterized in that
the belt loading matrix (q) is determined as a respective section-specific gravity distribution of the material mass flow q i,j in particular the segment-specific belt loading (q 1 , . . . , q m ), for each system-specific segment (i=1, . . . , m) and for each measurement (j=1, . . . , nk) and as a quotient of a drive efficiency η and the current conveyor belt speed V B,j , as follows:
q
=
❘
"\[LeftBracketingBar]"
q
1
,
1
q
2
,
1
q
3
,
1
q
m
,
1
η
/
V
B
,
1
q
1
,
2
q
2
,
2
q
3
,
2
…
q
m
,
2
η
/
V
B
,
2
q
1
,
3
q
2
,
3
q
3
,
3
q
m
,
3
η
/
V
B
,
3
…
…
…
…
…
…
q
1
,
nK
q
2
,
nK
q
3
,
nK
…
q
m
,
nK
η
/
V
B
,
nK
❘
"\[RightBracketingBar]"
.
6 . The method according to claim 2 ,
characterized in that
the total movement resistance force vector (ΔR) is determined as a quotient of a difference between a current drive power (P j ) multiplied by a drive efficiency (η)), and a current lifting power (P H,j ), and the current conveyor belt speed (Vb,j), B,j ), as follows:
Δ
R
=
❘
"\[LeftBracketingBar]"
(
P
1
η
-
P
H
,
1
)
/
V
B
,
1
(
P
2
η
-
P
H
,
2
)
/
V
B
,
2
…
…
(
P
nK
η
-
P
H
,
nK
)
/
V
B
,
nK
❘
"\[RightBracketingBar]"
.
7 . The method according to claim 1 ,
characterized in that
the section-related running friction resistance (f) to be determined consists of load-independent factors (f 1 , . . . , f m ) for each segment (L 1 , . . . , L m ) and an average idling power (P 0 ) of the belt conveyor system:
f
=
[
f
1
f
2
…
f
m
P
0
]
.
8 . The method according to claim 2 ,
characterized in that
a number of complete data sets “k” for a solution of the system of equations has at least twice a value of “m” and consequently an integer number “n” of complete conveyor belt rotations are stored in the evaluation device accordingly.
9 . The method according to claim 1 ,
characterized in that
a number of data sets of the varying data stored in the evaluation device corresponds to at least twice a number (>2 m) of the system-specific segments (L 1 , . . . , L m ) of the conveyor section for each conveyor belt rotation to be stored, wherein an oldest data set of varying data stored in the evaluation device is continuously overwritten by a most recent data set of varying data.
10 . The method according to claim 1 ,
characterized in that
for doubling or multiplying a number of equations in the system of equations in comparison to a number of unknown data present in the system of equations, a currently determined varying data per complete conveyor belt revolution are superimposed with the varying data of one or more previous complete conveyor belt rotations.
11 . The method according to claim 1 ,
characterized in that
the determination of section-related running friction resistance (f i ) based on variable data is carried out at least until each of the system-specific segments (L 1 , . . . , L m ) during a last complete rotation of the conveyor belt shows a minimal change in the material mass flow (Q s ) from a mean value calculated for this segment (L 1 , . . . , L m ), in particular in a range above 5% of a nominal load.
12 . The method according to claim 1 ,
characterized in that
transported mass quantities of a defined number of adjacent segments are added together and measured values with regard to a current drive power (P j ) and the current conveyor belt speed (V j ) are averaged in order to create a reduced system of equations.