China University of Mining and Technology

Xuzhou Jinbo Safety and Technology Co., Ltd.

Nanjing University of Posts and Telecommunicatins

Endoclot Plus Co.. Ltd

Heng Zhang

Yang Liu

Caiping Lu

Ding Li

Wenjun Lv

Xiaohui Li

Shanshan Gu

Feiyan Ji

Xiaohui Mao

A first sector patch and a second sector patch are loaded on a dielectric substrate having any dielectric constant. The circumferences of the first sector patch and the second sector patch are connected to the dielectric substrate by means of vertical shorting walls, respectively. Notches, a coaxial feeding probe, and a shorting pin are loaded on the first sector patch, so that the first three radiation patterns of the antenna are excited, disturbed and aggregated, and radiation null points which can be scanned along with a frequency change are symmetrically generated on a horizontal plane; moreover, addition of the second sector patch realizes a single-direction null frequency scanning function on the horizontal plane.

Horizontal-plane null frequency scanning antenna

Disclosed is a method for rock burst prevention by active support reinforcement and active pressure relief. The method comprises the following steps: A. rating a burst tendency based on a comprehensive index method: determining a zone as a general risk region or a mediate risk region by using a comprehensive index method; B. predicting a burst risk region and determining pressure relief borehole parameters in real time by using a drill cuttings method: determining borehole parameters of the general risk region and the mediate risk region; C. drilling holes after determining arrangement patterns of large-diameter pressure relief boreholes according to different burst risk levels; D. forming a 'coal wall-bolt-grouting hole sealing' support reinforcement system through a roadway support system; and E. monitoring a pressure relief effect of the support reinforcement system: until a required effect of preventing bursts by pressure relief is achieved while the support is reinforced. The present invention can not only achieve an effect of preventing rock bursts by pressure relief but also enhance the integrity of a coal wall in a roadway excavation process, thereby achieving the objective of rock burst prevention by active support reinforcement and active pressure relief.

Method for rock burst prevention by active support reinforcement and active pressure relief

The present invention discloses a combined automatic anti-explosion method for a gas drainage pipeline, comprising specific steps of: preparation of an anti-explosion installation piping; connection of the installation piping and the gas drainage pipeline; assembly of a porous foam material and an automatic control valve; installation of an automatic powder-spraying device and a signal analyzer; installation of a temperature sensor and a pressure sensor; and signal processing and automatic anti-explosion. According to the present invention, the porous foam material is located in a bottom groove of an arched pipeline when no gas explosion occurs in the gas drainage pipeline, without affecting the extraction effect of the gas drainage pipeline. If a gas explosion occurs, the present invention blocks the pipeline with the porous foam material due to its fire resistance and pressure reduction performances, and the automatic powder-spraying device sprays a certain amount of a dry powder explosion suppressant to reduce the explosion overpressure generated in the gas explosion process and isolate the propagation of flame, so that the safety performance of the gas drainage pipeline is ensured, and thus the safety production of coal mines can be ensured.

Combined automatic anti-explosion method for gas drainage pipeline

Growing community of inventors

Jiangsu, China

Heng Zhang