Coal mine hydraulic control valve bracket on the handlebar safety limit device design and analysis

 

Keywords hydraulic support; maneuvering valve handle; safety limit device; implementation

 

A design analysis

 

1.1 technology

 

Fully mechanized coal mining face with hydraulic steering valve bracket, handle flip device without any restrictions. Since Operation Fully Mechanized Coal Faces narrow space environment, manipulating valve function and require it to be conducive to the installation location of personnel to operate, not too subtle. So there is a result of being accidentally blown handlebar occur, extrusion and other forms arising from an accident caused by malfunction of the possibility of causing damage to equipment affecting production, or even personal injury. Therefore, the proposed coal mine hydraulic support additional control valve handle safety limit device for analysis of this subject.

 

This device is designed to fill the gaps in the field of the technology. Coal mine hydraulic support equipment belonging to the safe use of technology.

 

1.2 Technical Analysis

 

Coal with various types of hydraulic control valve bracket are more monolithic valve with handle fixed with four screws in series to form a valve seat installed in the hydraulic support. Hydraulic control valve handle bracket safety limit device that combines the structural characteristics of valve design and installation, but also requires staff to facilitate mine operations, and is suitable for underground narrow operating space environment. That is, from the structure is simple, convenient and practical, security and other aspects of the development program, designed to solve the technical problems of this device.

 

2 designs

 

2.1 program icon

 

2.2 specific programs

 

Coal mine hydraulic control valve bracket on the handlebar safety limit device, designed the main structure as shown: Mounting plate [1] and the fixed sleeve [6], plate [2] welded into one. Mounting plate [1] on the design of the mounting holes, and its positioning on the side of the valve size and connection of the two positioning holes the same, the original design of the hydraulic control valve of the two bracket bolts lengthened, with valve [9] series fixed This safety limit device can be formed integrally with the valve for easy and reliable installation in hydraulic support seat. Fixed shaft [3] through the fixed sleeve [6], the lower mounting ring [5], then use the cotter pin [4] fixed, the upper hinge hole design structure with hinge hole stopper bolt [7] through connections.

 

2.3 program features

 

1) control valve handle coal mine hydraulic support the safety limit device, designed to hinge rotating structure. The main structure includes mounting plate [1], the fixed shaft [3], the fixed sleeve [6], limit structural bars [8] ("U" shape). Which limit structural bars [8] is the control valve handle effectively prevent malfunction, a direct role to play safety components;

 

2) As for coal mine hydraulic support control valve handle on the safety limit device. Its design structure is suitable for all types of hydraulic outriggers, just under stand how much control valves of different sizes to select the required machining limit rod [8];

 

3) The program device structure design salient features: easy to use. Control valve [9] does not work when the handle are placed in zero position, the stopper rod [8] down to turn the handle to lock the control valve position, the equivalent of "sets" live all handlebars. The need for hydraulic support hand operation work, the stopper rod [8] off, and then with the fixed shaft [3] Without prejudice to rotate along the side of the job can be as simple as using a rotary switch;

 

4) The design of this device has a variety of the first, the main structure of the direct type is reflected in stopper rods [8] on a fixed way, is not there before styling and bolt type chain connector two ways. Ultimately through small-scale practice, to determine such a rotary switch type. This rotary switch type stopper rods [8] will not be lost and not easily damaged, and this connection is fixed way, the most effective means to achieve a safe operation limit convenient, fast and safe, suitable for underground working environment design concept .

 

3 Design Features

 

1) hydraulic control valve bracket on the handlebar safety limit device design features, combined with the structural characteristics of valve design structure is simple, convenient and practical, and conducive to safe operation. Its structure is suitable for all types of hydraulic outriggers. Various types of hydraulic control valve bracket, as shown in [9] indicate by multiple monolithic valves with handle series with four bolts fixed to form valve seat installed in the hydraulic support with horizontal and vertical two kind of installation;

 

2) hydraulic control valve handle security holder stopper, stopper rods are designed [8] for the U-shaped rod, to ensure the stopper rods [8] work according to operational needs, in a safe and effective range of flexible rotation, installation plate [1] designed to restrict the front stopper rods [8] the rotation stopper surface, when the stopper rod [8] is perpendicular to the fixed shaft [3] position, the stopper surface of the top of the stopper rod front end edge [8] side, so that the retainer lever [8] can not continue to rotate in order to ensure the retainer lever [8] hanging in a secure location, do not interfere with the safe operation of hydraulic support.

 

4 program implementation

 

Coal mine hydraulic control valve bracket on the handlebar safety limit device in October 2008 formally batch processing and production, into the underground coalface use. First used in ZY3600-11/28 type hydraulic support, and later extended to ZY4800-19/40 type hydraulic support. Now Qianjiaying Kailuan Mining Branch has been fully promote the use of the various models of hydraulic support of seven kinds of specifications. After several years of practice and continuous improvement, the formation of this article discusses the optimal structure. This coal mine hydraulic control valve bracket on the handlebar safety limit device has applied for a national patent, and is ready to promote the use of the global scope.

 

5 Conclusions

 

Coal mine hydraulic support control valve on the safety limit device handle the promotion and application, there are medium-temperature flue system working principle is to use the mill inlet vacuum extraction point and the pressure difference between the formation of the high-temperature, low-oxygen smoke gas chamber to be pumped out from the steering, into the milling system, changing the drying medium composition, reducing the oxygen content of the milling system terminal at 16% or less, to meet a large proportion of lignite blended after milling system safety explosion-proof requirements. The system advantages: 1) high temperature smoke extraction point, low oxygen content, which can contribute to drying and milling system to meet explosion-proof requirements; 2) vacuum gas extraction point smaller, the need to overcome the resistance; 3 ) drawn from the boiler flue gas piping impact of major equipment, without additional power, pipeline installation convenience and low cost.

 

Milling system boiler flue gas temperature in the transformation of the former system, the mill outlet temperature below 60 ℃, the worst conditions, sometimes below 50 ℃, milling system terminal is about 18% oxygen. Among temperature flue transformation, mill ventilation maintained at 170 000m3 / h or so, end milling system controlled at 16% oxygen, the mill outlet temperature can reach 60 ℃ or more, compared with the cold flue systems, milling down 2% oxygen end of the system, the outlet temperature increase above 10 ℃. Blended in a large proportion of lignite, the milling system to meet explosion-proof drying capacity and improve the design requirements of the milling system ventilation unit operation can meet the requirements. Through the medium temperature furnace smoke Burning lignite renovation and related tests, the following conclusions:

 

1) lignite blended with 70%, and put in the flue gas temperature, the mill inlet vacuum maintained at between 1 000Pa ~ 1 200Pa, the mill outlet temperature can be maintained at 60 ℃ ~ 70 ℃, pulverizing system terminal oxygen were lower than 16%, to meet a large proportion of blended flour when the explosion and lignite drying capacity requirements;

 

2) lignite blended with up to 70%, and put in the flue gas temperature, the coal fineness R90 40.3% under the test conditions, the measured maximum output of mill 70.8t / h, total output of the mill to achieve the required margin requirements; 3) When the temperature of flue gas into the system, the unit load is about 185mW, the blending ratio of 70% or less measured boiler thermal efficiency 91.89%, after a revised 91.11%; when the unit load is approximately 155mW when blended below 80% the proportion of actual boiler thermal efficiency is 90.50%, as amended, was 90.87%.

 

Since November 2009 to complete the transformation temperature flue system to solve a large proportion Burning lignite drying capacity after pulverizing system and safety explosion problem. 2010 annual Burning lignite, coal pulverizing system outbreaks did not occur. Two furnaces pulverizing power consumption 1 to December average completion 22.13kW · h / t of coal, compared with the same period decreased 1.04kW · h / t of coal, 1 to December total coal consumption 1 604 709t, lower power consumption due to milling total reduction plant electricity consumption 1,673,770 kW · h.

 

3 Conclusions

 

With the development of electricity production, a substantial increase coal for electricity, fuel supply problems and reduce electricity costs insurance will become more prominent contradictions, in order to ensure stable coal, lignite Huolinhe blended with a large proportion of the increasingly heavy burden requirements are also increasing. I blended lignite and related rehabilitation measures, both effective mitigation of coal tension, while ensuring the safety of the boiler economy and stable operation.