CHAPTER XXVI

WATER SUPPLY, LIGHTING, HEATING AND

VENTILATION

Water Supply

PROVISION for water supply to the foundry is a matter of the first importance. If water cannot be obtained from the public mains, facilities for pumping and distributing must be provided. The system must be so arranged, either by elevated tanks or otherwise, as to furnish water under a pressure of from 25 to 30 pounds. While the supply must be abundant, the natural tendency to its wasteful use must be suppressed.

Conveniently located near the cupola for quenching the dump, should be a hydrant with hose attached, ready for immediate use. Pipes should be so run about the foundry that taps may be conveniently distributed for wetting down the floors and sprinkling the sand heaps; each floor must have easy access to the sprinkling hose. Ample provision should be made for drinking; basins near the drinking fountains, in which to bathe their arms and faces, add greatly to the comfort of the workmen. The illustrations herewith, taken from the Iron Age, show provisions

made for this purpose and for lavatories, etc., in a large Cleveland foundry.

Running water should be supplied at the closets. In many foundries of recent construction, wash basins, shower baths and lockers are provided, enabling the men to wash and change their clothes before leaving the works. The free use of water implies, of course, a system of sewerage. Care must be taken to avoid puddles or wet spots about the floors. The matter of water supply for fire protection is entirely independent of that for foundry purposes, and should be provided for separately.

Lighting

Next to water supply in importance is the matter of lighting. Many foundries are deficient in this respect and suffer either in the character or quantity of product from improper lighting. Daylight is invaluable, and should be utilized to the fullest extent. In the construction of foundry buildings, the windows should be tall and as close together as the character of the structure will permit; they should not extend lower than four feet from the floor. A modern construction showing the sides of the building made almost entirely of glass is shown in the engraving below.

Windows in the moniter should be swiveled and arranged to open easily for ventilation. Skylights are to be avoided if possible, as they cause no end of annoyance. The weaving-shed roof gives excellent results, and is frequently used in foundry construction. The glazing should be of a character to prevent the direct admission of sunlight. Ground glass, wire glass or glass with horizontal ribs afford a mellow light, relieving the eyes from the glare of direct sunlight.

Artificial light for the early morning and late evening hours, during the season of short days, is best afforded by some adaptation of the electric lamp. Tungsten lamps in groups of four, distributed at intervals of about 40 feet are largely used. Such lamps are provided with reflectors to direct the rays downwards and diffuse them. The lamps must be placed so as to clear the crane ways, and should be elevated about 20 feet from the floor. The Cooper-Hewett mercury lamps, placed about 50 feet apart and covered with reflectors, are very satisfactory. The flaming arc lamps, similarly placed, furnish the greatest illumination for a given expenditure of current.

A recent type of kerosene burner, the Kauffman, having a mantel somewhat similar to the Wellsbach, is said to furnish a given candle power at less cost than any lamp known.

With any system of lighting, care must be taken to keep the lamps clean and in good order, otherwise their efficiency is soon greatly impaired. Where electric lights are used, the generators should be independent of those which furnish current to the motors. Power for fans, elevators, cranes, sand mixers, etc., is most conveniently supplied by electricity. Each machine should have an independent motor. Electric trucks, operated by storage batteries, and magnetic hoists, for service in the foundry and yard are almost indispensable. In fact the introduction of electricity has so simplified foundry operations that its use is imperative.

Heating and Ventilating

Heating and ventilating the foundry are subjects which formerly received little attention. A few stoves or open fires in iron rings, placed where they would be least in the way, constituted the usual equipment; foundries fitted with steam heating or hot-air systems were exceptional.

Gradually foundrymen have learned to appreciate the advantages of a comfortable working temperature and good ventilation, as shown by increased output. A cold shop and chilled or partly frozen sand heaps may easily reduce the value of a morning's work from 20 to 25 per cent. As foundry operations require active physical exertion, the temperature of the shop should not exceed 50° to 55° F. At 7 o'clock in the morning the building should be warm throughout. For this purpose direct and vacuum steam heating systems are used with good results. Both are open to objections. The warm air is not evenly distributed; much of it is sent to the upper part of the building, where it does no good. With either system several hours are required in extremely cold weather to produce a comfortable temperature in the morning. Cold air enters through the windows and doors, causing drafts and an uneven distribution of heat.

More satisfactory results are furnished by the fan and hot-blast system. This consists of a sheet-iron chamber, in which are placed the requisite number of coils heated either by direct or exhaust steam, if the latter is available, an exhaust fan and the distributing pipes. The fan draws the air over the coils and from the chamber and forces it about the building through large ducts, from which branch pipes are taken at proper intervals; through these branches the warm air is discharged at the desired spots within the shop. This system is largely used and possesses advantages over those having direct radiation.

The amount of heat absorbed by air flowing over pipes increases rapidly with the velocity of the air. When the velocity of the air current flowing over the pipes in the heating chamber is about 1500 feet per minute (the usual velocity) the area of the heating surface required to accomplish a given heating effect is only about one-fifth that for direct radiation. With the fan and hot-blast system the building is filled with air under slight pressure, termed a plenum, which prevents cold air from entering; warm air flows out through all leaks. The warm air is discharged from the pipes near the floor, and uniformly distributed through the lower part of the building. By reason of such distribution and the great volume of air discharged, the shop may be quickly warmed in the morning. If the fan is driven by an independent engine, the exhaust steam is sent directly to the coils, thereby making the expenditure for power nominal. Where live steam is not available for an engine the fan may be driven by a motor. With the motor-driven fan, the watchman can start the apparatus during exceedingly cold nights, and thereby prevent the sand heaps from freezing. The ducts are usually circular in section, made of galvanized iron and supported by the chords of the building so as to clear the crane way.

The sketch below shows the usual arrangement for fans and ducts. In shops of moderate size, where but one fan is required, the ducts, of course, must run all around the building.

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FIG. 244.-Typical Arrangement of Heating and Ventilating System for Foundry with Unobstructed Craneway.

From the ducts, discharge pipes are dropped at intervals of from 30 to 40 feet. These usually terminate about 8 feet above the floor line, and leave the ducts at an angle of about 45°, inclined in the direction of the