Fig. 442.
Fig. 443.
This is one of the most successful mine sinking pumps designed; there are no parts exposed to rust, and instances have occurred when this pump has started off and cleared a shaft of water when the pump itself had been buried for weeks under a mass of fallen rock and debris.
This pump has no outside valve gear, arms or levers; all movable parts are inside and enclosed, to prevent collision with the walls of the mine shaft nor is it likely to receive injury from blast explosions. Being fitted with special exhaust cut-off, it will continue to run as fast as steam will drive it (with an irregular or intermittent supply of water, or when the water fails entirely,) not only without danger of the piston striking the heads, but without injury to the valves. It is designed and intended to handle gritty water.
Telescopic pipe joint shown in Figs. [442] and [443], supplies a convenient means for lifting and lowering a sinking pump, and is usually made in lengths of sixteen feet. This enables the operator to drop the pump that distance without disturbing the rest of the pipe; by its use irregular lengths of pipe can be added, whereas, otherwise when the pump is lowered the pipe would have to be cut of equal length.
The inside pipe is brass tubing which freely slips through the packing and is non-corrosive.
Fig. [441] exhibits the sinking pump in practical operation; it is the same as that shown on the previous page.
Note.—Mining pumps require to be made “to gauge” and interchangeable; an advantage which commends itself to experienced mining engineers. Many “parts” should be provided in duplicate on account of the rough usage and hard service alluded to above.