Long-distance large-section single-row tunneling ventilation analysis The existing technical means is to strengthen the ventilation management, mainly to strengthen the air duct management, such as improving the quality of the air duct, the quality of the hook, the performance of a single fan, etc., but it is fundamentally difficult to increase Effective air supply to the working face. Therefore, this technical problem can only be solved in the way of ventilation. There are three types of local fan combined ventilation: 1 two central fans in series and two local fans in series can significantly increase wind pressure, but it also doubles the pressure on the air cylinder. First, the pressure resistance of the air cylinder is required to be higher, but the existing air duct does not reach this index, which is easy to cause a burst accident; secondly, the air duct joint can not withstand the same high pressure and breaks the accident; Third, the operator is quite difficult to dock the air duct, especially the air duct that is disconnected in the middle, so it is difficult to ensure the quality and safety of the air supply to the working face. Therefore, this type of ventilation is generally not used.
2 Two local fans in parallel and two local fans in parallel can increase the air supply, but the increase in air supply depends directly on the growth rate of wind resistance. Due to the large wind resistance of the long-distance large-section single-lane tunneling ventilation, in actual work, the air volume of the two local fans is smaller than that of a local fan, and the efficiency of each local fan is very low. It is far from meeting the requirements for the use of the driving face. Therefore, this type of ventilation is not used.
3 Two or more local fan joints and two local fan joints can make the heading face obtain higher air supply volume and wind pressure, but the second (three) ministry fan is placed deep in the roadway, basically arranged in the wind flow. Does not meet the requirements of safe production. Therefore, an auxiliary road should be excavated at a section of the total length of the roadway at 1/32/5 to form a buffer room, and then supply a wind to the deep part of the roadway, thus ensuring safety and meeting production needs. Therefore, choose this type of ventilation.
Long-distance large-section single-span excavation press-in type local fan combined ventilation method implementation of push-in type local fan combined ventilation design and arrangement of press-in type fan combined ventilation design, mainly composed of secondary fan relay supply air, central windä¾› Supply the wind to the heading face. The primary fan can be composed of one or two local fan clusters of the same type and the same power, and installed in the same location. The air duct of the same diameter and the same constituent material provides fresh airflow to the central wind, because under the same conditions Operation, the air pressure and air volume of its import and export are nearly equal, easy to manage operations. The secondary fan consists of a local fan and then supplies air to the tunneling face. Therefore, the air volume and the airflow quality of the tunneling face are improved, and the working environment requirements are met, without disturbing the normal tunneling process.
Press-in type fan combined ventilation mode working principle Press-in type fan combined ventilation mode is equivalent to the two-stage press-in type of fan-spaced series connection. Therefore, its working principle is divided into two sections for analysis: AB section : Two independent air ducts can be regarded as parallel ventilation. The main characteristics of wind pressure air volume are: hc=h1=h2, Qc=Q1+Q2. However, it is more effective in reducing wind network resistance, increasing air volume, and exerting the efficiency of each local fan.
BC segment: The two-stage ventilation fan is connected by wind, which can be regarded as a series ventilation with a large interval. The main characteristics of the wind pressure air volume are: hc=h1+h2, Qc=Q1=Q2. However, it is more effective in increasing the air volume and making each of the bureau fans operate efficiently.
The important parameters of the press-in type fan combined ventilation method are selected as the first-stage air supply fan: taking into account the air volume loss of the air duct and making full use of the original idle fan. Therefore, in consideration of the overall supply of air, the efficiency of the first stage must be above 85%. If this indicator is not met, the ventilation of each of the two local fans should be implemented. The second-level wind supply bureau fan: should consider the wind loss of the wind, and make full use of the idle fan capacity. Therefore, in consideration of the overall supply of air, the efficiency of the second stage must be 80% 90%. If this indicator is not met, the first stage fan should be adjusted.
The principle of determining the position of the wind and the wind (1) must avoid the high gas emission area to ensure the quality of the secondary supply. (2) The air volume provided by the first-stage bureau fan must be greater than or equal to the air supply volume of the second-stage bureau fan. The factor is 11001105, which increases with the increase of air leakage in the diverticulum. The air volume counteracts the amount of air leakage.
Press-in type fan-fan combined ventilation method can be guessed and verified by the example of ventilation from the official site of Xishan Coal and Electricity Group Corporation. In April 1992, the ventilation of the underground mine of Xishan Coal and Electricity Group Co., Ltd. in the Nanda Lane was a two-stage press-in ventilation. The first stage used two local fans of the same type and the second stage adopted one. The bureau fan can also be called the three-way fan combined ventilation.
SCS series digital modularization Electronic Truck Scale consists of Digital Load Cell, Digital Weighing Indicator and modularization platform. Digital technology improves the quality of electronic Truck Scale and makes it have more convenient adjustment, safer operation, easier maintenance, quicker communication, higher intelligence and stronger anti-interfering performance.
Portable Truck Scales,Digital Truck Scales,Digital Load Cell Truck Scale,Truck Scale With Digital Indicator
SHANDONG JINZHONG SCIENCE & TECHNOLOGY GROUP COMPANY LIMITED , http://www.chinagoldbell.com