SU1506292A2 - Method of checking conveyer ballance - Google Patents

Abstract

The invention relates to a weight measuring technique, in particular, to methods for calibrating weighing conveyors. The method improves the accuracy of verification by eliminating the effect of belt tension and uneven running loads. The verification consists in comparing the results of measuring the current performance of a conveyor with its calculated value obtained by measuring the mass of single samples and the speed of movement of the belt. Continuously record the current performance on the same unloaded and loaded with the material measuring section of the tape when loaded in both cases, the tape along the rest of the length of the conveyor. The actual linear load recorded by the weights in one material sampling zone corresponding to the length of the weight section is determined by averaging samples taken from two consecutively located and alternating sections. The method provides high accuracy of calibration when the scales are inserted anywhere along the length of the conveyor and the material is unevenly arranged along the length of the belt. 1 il.

Description

3150

The method is carried out as follows.

Preparing for Calibration Set the recording span of the plotter V-20P mm on the Y axis at a current of 5 mA, on the X axis - 0.05 s / mmo

Scale verification. It turns on the conveyor and loads the material with the material with the entire tape, except for the dimensional section between the marks M and M. Record the indications of scales 9 on the unloaded measuring section. The beginning and the end of the measuring section are marked on the diagram of the plotter 4 marks; Then they load the conveyor belt with the material, including the measuring section, and again record the indications of the weights 9 on the measured portion of the city. After passing the measured portion through the weights 5, the conveyor is stopped. Using a cutter, the material is removed from three zones of the tape of the measured section. The length of each zone of removal is 21, that is, it is equal to twice the length of the weight section of the tape. Loose material is weighed on a model balance and the average linear load is determined:

- (q, + q) / 2o

With respect to the time plotter 4, the plotters record the weights when the tape is moved to the length of one weight area 1 with averaging two successive samples q and q and q and q determine the average value of the current productivity a; with a gett signal recording with an unloaded measuring section.

The speed of the tape is defined as the quotient of the division of the length of the 1-dimensional section by the time J of its movement along the weights:

V - 1 „/.

The error of the weights 9 in each sampling zone is determined by the formula

L

 0. Q G

100%,

productivity of the conveyor in the zone of material selection, calculated from the record 55 plotter, t / h; conveyor productivity, obtained by the results of the selection and weighing of the material, t / h.

R

Q "chks --e.

a - the average value of the recording amplitude in the sampling zone, mm;

And - the highest value of the selected recording amplitude, mMo

Qj 3.6,

where q is the average load in the sampling zone kg / m;

V - conveyor belt speed in the sampling zone, m / s. The verification process is performed at three points of the range of variation of the linear load within 20–100% of the nominal value.

Consider an example with the following parameters of the pipeline; linear load q | 5000 N / m, the running weight of the belt q is N / m, the angle of inclination of the conveyor / i 18 °, the coefficient of resistance to movement W 0.04, the length of the weight section 1 1 m, the difference between the levels of installation of the weight and stationary rollers h 0.0005 m, the distance of the place of installation of the scales from the tension drum L is 200 m.

Tension of the tape in the place of installation of the weights according to the proposed method under loading along the entire length of the conveyor (except for the measuring section 1 vv mm):

 With L (qg q - 1l. I rlCcos / bw + + sin) 386280 But

Methodical error of verification for 100% of the nominal load of the proposed method

 200 (,) b. 0.35%.

Example. On weights, starting with the mark M, a section of the tape of length 1, and on the plotter the current capacity a is recorded, respectively, during the time t 1 / v. Two linear loads (linear densities), replacing each other over the weight roller q 300 kg and q. 350 kg, averaged, Tov. the actual impact on the scales will be

qo (q, - q,) / 2 325

kg

When removing and weighing a sample of a material by a solid method with only one ka length, t.v. q, 300 kg, on the weighing scales, the determination of the calibration will be

fcr

ion -E

.3j - 3 q

Claims (1)

The application of the proposed method completely eliminates this component of the error. Invention Formula The method of calibration of conveyor scales t5 auth.St. No. 1281916, characterized in that, in order to improve the accuracy of verification by eliminating the influence of tension, the cooperative leites and non-linear load loads, in it also fix the current performance of the weights on the same tape segment, unloaded and loaded with material, with loaded in both cases, the tape over the rest of the length of the conveyor, and the actual running load recorded by the weights in one material removal zone corresponding to the length of the weight section is determined by averaging the samples removed with x and two successive shifts of each other constituent portions. YoGorn Editor Compiled by M. Zhukov Tehred A. Kravchuk Order 5420/43 Circulation 660 VNIIPI State Committee for Inventions and Discoveries at the State Committee on Science and Technology of the USSR 113035, Moscow, Zh-35, Raushsk nab. 4/5 Proofreader E. Lonchakova Subscription