Upcast Sentence Examples
In a mine with shafts opening at the same level, natural ventilation once established will be effective during cold weather, as the downcast will have the temperature of the outside air, while the upcast will be filled with the warm air of the mine.
The usual form of ventilating furnace is a plain fire grate placed under an arch, and communicating with the upcast shaft by an inclined drift.
In main( ), when you place something inside the Instrument array you automatically upcast to Instrument.
In any case whether natural or artificial means be employed, a mine can only be ventilated properly when it has at least two distinct openings to the surface, one an intake or " downcast," the other a chimney serving as an " upcast."
The fire should be kept as thin and bright as possible, to reduce the amount of smoke in the upcast.Advertisement
Wooden guides being of considerable size, block up a certain portion of the area of the pit, and thus offer an impediment to the ventilation, especially in upcast shafts, where the high temperature, when furnace ventilation is used, is also against their use.
Create a Rhomboid, upcast it to a Shape, then downcast it back to a Rhomboid.
The fire was discovered by smoke in the upcast shaft.
Second, in the array definition for b this code attempts to create a new mi and upcast the address to a MBase*.
This colliery sited at the entrance to the Ely valley was the upcast shaft.Advertisement
In main(), when you place something inside the Instrument array you automatically upcast to Instrument.
So far as possible, vitiated air is led directly to the shaft instead of passing through other workings; for example, mine stables when used are placed near the upcast shaft and ventilated by an independent split of the ventilating current.
The use of two independent connexions - whether separate pits or sections of the same pit, between the surface and the workings - is necessary for the service of the ventilation, fresh air from the surface being carried down one, known as the " downcast," while the foul or return air of the mine rises through the other or " upcast " pit back to the surface.
This is effected by carrying through the workings a large volume of air which is kept continually moving in the same direction, descending from the surface by one or more pits known as intake or downcast pits, and leaving the mine by a return or upcast pit.
Such a circulation of air can only be effected by mechanical means when the workings are of any extent, the methods actually adopted being - (i) The rarefaction of the air in the upcast pit by a furnace placed at the bottom; and (2) Exhaustion by machinery at the surface.Advertisement
The return air from fiery workings is never allowed to approach the furnace, but is carried into the upcast by a special channel, called a dumb drift, some distance above the furnace drift, so as not to come in contact with the products of combustion until they have been cooled below the igniting point of fire-damp. Where the upcast pit is used for drawing coal, it is usual to discharge the smoke and gases through a short lateral drift near the surface into a tall chimney, so as to keep the pit-top as clear as possible for working.
These are made to shut air-tight against their frames, so as to prevent the air from taking a short cut back to the upcast, while preserving free access between the different districts without following the whole round of the air-ways.
The increased resistance, due to the large extension of workings from single pairs of shafts, the ventilating currents having often to travel several miles to the upcast, has led to great increase in the size and power of ventilating fans, and engines from 250 to Soo H.P. are not uncommonly used for such purposes.