The blast can be carried for very considerable distances from the blowing engines without much loss of pressure and with but little expense. It is therefore possible to locate the blowing engine house at a considerable distance from the furnaces, but of course it is very undesirable to carry the steam any further than is absolutely required. This means that the boiler house must be located close to the engine house, and as the gas from the furnace must be brought to the boiler house the location of the latter is deserving of considerable study.

At small plants attempts have been made to set boilers and stoves close together so that one man could attend both sets of burners, and this is, on many accounts, an excellent idea, but cannot generally be followed at larger plants, and therefore a location is chosen for the boiler house which will give the shortest and most convenient gas main to reach it and at the same time give the best steam connections to the engine house. It might almost be said to be standard practice to put the engine house and boiler house parallel and close to one another, although very many plants have departed from this practice for one reason or another.

Where room is an important consideration these two buildings can be placed in spaces relatively difficult of access without much detriment because very little material has to be hauled to or from them on railways, but, of course, provision must always be made to bring in an ample coal supply for the boilers even though it be useless 95 per cent. of the time.

It is almost indispensable that the engine house should be served with a track to handle the heavy parts of blowing machinery during erection and subsequently during repairs, but these tracks being very little used need not have the location and alignment required for tracks carrying a continuous and heavy traffic.

The number of furnaces served by a single blowing plant must be decided by the general arrangement of the plant along the lines laid down above. The expense of carrying the blast is, as there stated, not very heavy. At the same time if it were attempted to supply blast for a large plant of eight or ten furnaces from a single blowing engine house the quantity of piping involved would become very large, and the room which these pipes would take up running, in many cases, close to one furnace in order to reach others would be a very serious matter. For this reason it is possible that four furnaces is about the limit of the number that can be advantageously blown from a single engine house. Moreover, it is to be noted that when the number of engines in the plant has reached the limit of what one given crew can supervise adequately another crew then becomes necessary, or a large portion of one, and it makes little difference in the operating cost whether these be in one house or in two, while it makes an enormous difference both in cost and in room required if blast pipes for more than four furnaces have to be distributed from a single blower house.

The electrical, compressed air and dry-blast plants are almost always located, as they should be, in or adjacent to the blowing-engine house so as to be under the charge of the blowing engine operators, and served by the cranes installed over the blowing machinery. The feed pumps for the boilers were formerly in the same building but are now very generally placed in the boiler house proper and put under the charge of the boiler house attendant. The pumping plant must be located primarily with relation to the water supply, and while it is exceedingly desirable that this also should be in the main power house it is not always possible to arrange it in that location without sacrificing even more important considerations. At the same time the cost of attendance of isolated plants of relatively small power is very high as compared to that in a single large power house, and for this reason the pumping plant should be either in the main power house or as close to it as practicable.

Arrangements For The Disposal Of The Iron

These necessarily vary according to the purpose of the plant. If it be a component part of a steel works then the prime consideration is safe and convenient methods of hauling the ladle cars to and from the steel works. If on the other hand the furnaces constitute a merchant plant all the iron is required to be cast either in beds or a pig machine. In the latter case the location of the pig machine is a matter of some moment as is also the location of its service tracks. In an earlier chapter were given a description and illustrations of a pig machine plant with an excellent arrangement of "ladder" tracks. Such an installation can within reason be located wherever consideration of tracks and space require.

The Disposal Of The Slag

The prime consideration in this is that the runners shall be short since even the hottest and best-running cinder builds in the bottom of the trough and has to be cleaned out and disposed of before the next flush. The labor required for this increases almost as the square of the length of the trough and it is therefore very important to keep the latter as short as possible whether it is to discharge into a hot pot or into a granulating pit.

The location of the slag dump for the final disposal of the slag may be any distance up to one or two miles or even twice as much, but of course it is desirable to keep this distance as small as possible in order to diminish the time of the ladle cars and locomotives on the road and so enable the smallest number of them to perform the necessary service.