Grinding sound load analyzer capable of automatically reducing noise

Abstract

The utility model discloses a milling sound load analyzer capable of automatically reducing noise. A milling sound sensor is sequentially connected with a milling sound amplifying unit, a subtracter, an amplifying and filtering unit and a display output unit, and an environmental noise sensor is sequentially connected with an environmental noise amplifying unit, a signal delay unit, the subtracter, the amplifying and filtering unit and the display output unit; the grinding sound amplifying unit, the environmental noise amplifying unit, the signal delay unit, the subtracter, the amplifying and filtering unit and the display output unit are assembled in the host shell; the grinding sound sensor is arranged near the ball mill; the environment noise sensor is arranged on the outer side of the abrasion sound sensor. According to the invention, the mill sound signal and the environmental noise signal of the mill are respectively collected, and the two paths of audio signals are kept in phase synchronization through the time delay circuit and are processed by the subtractor, so that the noise in the environment is offset, the interference of the environmental noise is avoided, and the measurement precision of the mill sound load analyzer is improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of measurement and control instruments, and particularly relates to a grinding sound load analyzer for a ball mill. The grinding sound load analyzer can automatically pick up and eliminate environmental noise, and reduce the interference of environmental noise on the monitoring of the grinding sound of the ball mill. Background Technique

[0002] The grinding sound load analyzer is mainly used for monitoring the load of a mine ball mill. By using the signal spectrum analysis method, it analyzes and processes the sound intensity and frequency characteristics of specific frequency bands of the grinding sound, and synthesizes and outputs the mill material level signal. It has changed the situation that the mill load has been mainly judged by manual experience for a long time, ensured the safe operation of the mill, and improved the processing capacity of the mill.

[0003] However, due to the large number of large-scale equipment in the mine and the complex environmental noise, the grinding sound load analyzer is easily affected by the environmental noise. Especially when multiple ball mill devices are operating simultaneously, the grinding sounds interfere with each other, and it is very difficult for the existing grinding sound load analyzers to accurately detect the working conditions and loads of single ball mills, and the application of the grinding sound load analyzer is greatly restricted. Summary of the Invention

[0004] The purpose of the utility model is to overcome the technical problems that the existing grinding sound load analyzer is easily affected by environmental noise and the noises of multiple ball mills interfere with each other and affect the signal results, and provide a grinding sound load analyzer with automatic noise reduction.

[0005] To achieve the above object of the utility model, the following technical solutions are adopted for a grinding sound load analyzer with automatic noise reduction of the utility model:

[0006] A grinding sound load analyzer with automatic noise reduction of the utility model includes a grinding sound sensor installed close to and facing the ball mill. Its characteristics are: it also includes an environmental noise sensor installed outside the grinding sound sensor and facing away from the ball mill; the grinding sound sensor is sequentially connected to a grinding sound amplification unit, a subtractor, an amplification and filtering unit, and a display and output unit, and the environmental noise sensor is sequentially connected to an environmental noise amplification unit, a signal delay unit, a subtractor, an amplification and filtering unit, and a display and output unit; the grinding sound amplification unit, the environmental noise amplification unit, the signal delay unit, the subtractor, the amplification and filtering unit, and the display and output unit are assembled in the main housing.

[0007] Preferably, both the grinding sound sensor and the environmental noise sensor are horn speakers.

[0008] Preferably, the grinding sound sensor is connected to the grinding sound amplification unit through a shielded twisted pair wire.

[0009] Preferably, the environmental noise sensor is connected to the environmental noise amplification unit through a shielded twisted pair wire.

[0010] The audio signal of the ball mill collected by the grinding sound sensor of the present utility model, after being amplified by the grinding sound amplification unit, enters the non-inverting input terminal + of the subtractor; the environmental noise sensor collects the environmental noise audio signal, which, after being amplified by the environmental noise amplification unit, enters the signal delay unit. The signal delay unit delays the noise audio signal to make the phases of the noise audio signal and the mill audio signal synchronous, and then enters the inverting input terminal - of the subtractor.

[0011] The automatic noise reduction of the present utility model is based on the principle of destructive interference between two sound waves or sound radiation suppression, generating a radiation sound wave with a phase opposite to that of the sound source to be canceled, so that the results of their actions cancel each other out, thereby achieving the purpose of reducing noise.

[0012] After adopting the above technical solution, an automatic noise reduction grinding sound load analyzer of the present utility model has the following beneficial effects: Two sensors are adopted, one for collecting the sound signal during the operation of the mill and the other for collecting the external environmental noise. The environmental noise audio signal passes through the delay circuit to make the phases of the two audio signals the same. The two synchronized audio signals enter the non-inverting input terminal and the inverting input terminal of the subtractor simultaneously, making the phases of the two audio signals opposite, and they cancel each other out in the subtractor, automatically realizing the function of eliminating and reducing environmental noise. Description of the Drawings

[0013] Figure 1 It is a structural connection and principle schematic diagram of an automatic noise reduction grinding sound load analyzer of the present utility model;

[0014] Figure 2 It is an installation layout diagram of an automatic noise reduction grinding sound load analyzer of the present utility model.

[0015] The reference numerals in the drawings are: 1 - grinding sound sensor; 2 - grinding sound amplification unit; 3 - environmental noise sensor; 4 - environmental noise amplification unit; 5 - signal delay unit; 6 - subtractor; 7 - amplification and filtering unit; 8 - display output unit; 9 - main body housing. Detailed Embodiments

[0016] In order to further describe the present utility model, the following will describe an automatic noise reduction grinding sound load analyzer of the present utility model in more detail with reference to the drawings. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the scope of protection of the present utility model.

[0017] Please refer to Figure 1 、 Figure 2, the utility model relates to an automatic noise reduction grinding noise load analyzer, which is composed of a grinding noise sensor 1, a grinding noise amplification unit 2, an environmental noise sensor 3, an environmental noise amplification unit 4, a signal delay unit 5, a subtractor 6, an amplification and filtering unit 7, and a display output unit 8. The grinding noise sensor 1 is arranged at a distance of 0.3 m to 0.5 m from the ball mill and is installed facing the ball mill; the environmental noise sensor 3 is arranged at a distance of 1.5 m to 2 m from the ball mill and is installed with its back to the ball mill. The grinding noise sensor 1 is sequentially connected to the grinding noise amplification unit 2, the subtractor 6, the amplification and filtering unit 7, and the display output unit 8, and the environmental noise sensor 3 is sequentially connected to the environmental noise amplification unit 4, the signal delay unit 5, the subtractor 6, the amplification and filtering unit 7, and the display output unit 8. Except for the grinding noise sensor 1 and the environmental noise sensor 3, the rest of the electronic circuits are assembled in the main machine housing 9.

[0018] In the embodiment, both the grinding noise sensor 1 and the environmental noise sensor (3) are horn speakers; the grinding noise sensor 1 is connected to the grinding noise amplification unit 2 through a shielded twisted pair; the environmental noise sensor 3 is connected to the environmental noise amplification unit 4 through a shielded twisted pair.

[0019] The audio signal of the ball mill collected by the grinding noise sensor 1 enters the non-inverting input terminal + of the subtractor 6 after being amplified by the grinding noise amplification unit 2; the environmental noise sensor 3 enters the signal delay unit 5 after amplifying the collected environmental noise audio signal by the environmental noise amplification unit 4. The signal delay unit 5 delays the noise audio signal to make the noise audio signal and the mill audio signal phase-synchronized and enters the inverting input terminal - of the subtractor 6.

[0020] In the embodiment, both the grinding noise sensor 1 and the environmental noise sensor 3 are horn speakers with an impedance of 8 ohms and a power of 16 w; the grinding noise amplification unit 2 uses the NE5534 operational amplifier of TI Company, and the amplification factor is set to be adjustable from 1 to 30 times; the environmental noise amplification unit 4 uses the NE5534 operational amplifier of TI Company, and the amplification factor is set to be adjustable from 1 to 50 times; the signal delay unit 5 uses an RC resistance-capacitance delay circuit, and the delay time is adjustable from 1 to 10 ms to compensate for the time difference of receiving the noise signal caused by the different positions of the main sensor and the environmental noise sensor; the subtractor 6 is a subtractor circuit composed of the OPA197 precision operational amplifier of TI Company; the amplification and filtering unit 7 uses the NE5534 operational amplifier of TI Company, and the amplification factor is 10 times. The filtering unit uses a band-pass filter composed of the MAX274 active filter of MAXIM Company to select the working frequency band of the mill, and the band-pass filtering frequency band is set to 500 Hz to 4500 Hz; the display output unit 8 uses a digital tube to display the real-time working condition data of the ball mill and outputs a standard 4-20 mA current signal.

[0021] After the two-way signals of the utility model are processed by the subtractor 6, the noise in the environment is cancelled, and the noise reduction processing is realized. The signal after noise reduction output by the subtractor 6 enters the amplification and filtering unit 7 for amplification and band-pass filtering to select the useful frequency band of the grinding sound of the ball mill. The audio signal output by the amplification and filtering unit 7 is sent to the display and output unit 8 to display and output the mill load data in real time.

[0022] Although the embodiments of the present utility model have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principle and spirit of the present utility model. The scope of the present utility model is defined by the appended claims and their equivalents.

Claims

1. An automatic noise reduction grinding noise load analyzer, comprising a grinding noise sensor (1) installed close to and facing a ball mill, characterized in that: It also comprises an environmental noise sensor (3) located outside the grinding sound sensor (1) and installed with its back to the ball mill; the grinding sound sensor (1) is sequentially connected to a grinding sound amplifying unit (2), a subtractor (6), an amplifying and filtering unit (7), and a display output unit (8); the environmental noise sensor (3) is sequentially connected to an environmental noise amplifying unit (4), a signal delay unit (5), a subtractor (6), an amplifying and filtering unit (7), and a display output unit (8); the grinding sound amplifying unit (2), the environmental noise amplifying unit (4), the signal delay unit (5), the subtractor (6), the amplifying and filtering unit (7), and the display output unit (8) are assembled in a main body housing (9).

2. The automatic noise reduction grinding noise load analyzer according to claim 1, characterized in that: The grinding sound sensor (1) and the environmental noise sensor (3) are both horn-type loudspeakers.

3. The automatic noise reduction grinding noise load analyzer according to claim 1, characterized in that: The grinding sound sensor (1) is connected to the grinding sound amplification unit (2) via a shielded twisted pair cable.

4. The automatic noise reduction grinding noise load analyzer according to claim 1, characterized in that: The environmental noise sensor (3) is connected to the environmental noise amplification unit (4) via a shielded twisted pair cable.

5. The grinding noise load analyzer with automatic noise reduction as claimed in claim 2, characterized in that: The grinding sound sensor (1) is connected to the grinding sound amplifying unit (2) via a shielded twisted pair cable; and the environmental noise sensor (3) is connected to the environmental noise amplifying unit (4) via a shielded twisted pair cable.

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