Purchase of this book includes free trial access to ... where you can read more than a million books for free. Excerpt from book: Section 3CHAPTER V. Ventilation Of Bord And Pillar Workings. Plan 1 shews the Ventilation of workings in shallow seams. The air circulates through the headways or end nearest the face of the bords. The freedom of shallow seams from fire damp does not require that the bord faces should in all cases be ventilated. Plan 2 shews the system of ventilation adopted in the North, in working a seam in ...
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Purchase of this book includes free trial access to ... where you can read more than a million books for free. Excerpt from book: Section 3CHAPTER V. Ventilation Of Bord And Pillar Workings. Plan 1 shews the Ventilation of workings in shallow seams. The air circulates through the headways or end nearest the face of the bords. The freedom of shallow seams from fire damp does not require that the bord faces should in all cases be ventilated. Plan 2 shews the system of ventilation adopted in the North, in working a seam in districts or panels. The middle road is the main travelling-road of the mine, and also the intake or fresh air-road; the two side-roads are return air-roads. No air-doors are fixed on the main-roads. Each panel or district takes its supply of air from the middle main-road, and is controlled by a regulator fixed on the return from each. When the air has ventilated the faces of the main-roads, it is conducted to the faces of the bords in each panel by means of bratticing from the headways or end next to the face, and at the bottom of the bratticing in the headways or end, a swing door or cloth is hung to allow a passage for the tubs. The air passes from the bords or whole coal workings to the faces of the pillars in the same panel, along which it sweeps and presses towards the goaf, forcing the gas from the men at theface, and finally being sent over a part of the goaf into the return air-course, it is conveyed into the up-cast shaft without going along any of the travelling-roads of the mine. The advantage of this arrangement of the ventilation over that where the air circulates through the mine in one current is evident when bodies of gas are liberated from the goaves by atmospheric changes, or sudden outbursts take place. The main-roads between the panels can be separately ventilated if the state of the mine requires it. Plan 3 shews the method of ventilating seams having an inclination, and being worked in districts ...
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