Sept.,
1912
T H E J O C R S A L OF IAVDL-STRI.4L A N D E N G I N E E R I N G C H E M I S T R Y .
the usual manner. For suction purposes, the spiral armoring wire is most satisfactory if put around the inside rubber lining, for it tends then to prevent the drawing-in of the canvas when pumping commences. For pressure hose, it is considered advisable to have the layer of canvas rolled on to the inside rubber coating, the wire armoring then being proceeded with on the top of this. There are three general forms of suction hose: round wire suction, flat wire suction, and internal wire suction. Some times the hose is bound with cord after the cloth wrapping is carried out. Outside armoring is advised only where there is rough usage. ~
689
to arrange the movement of the main pumping plunger so that it will trave! from its extreme position a t the end of the stroke inwardly much or little and the pump may just comfortably handle the amount of dirty oil which it receives without drawing large quantities of air through the receiving well of the dirtyoil system. The driving rod connecting from the engine to the pump is in. pipe. The pump casting has a hollow portion in the top which acts as an air cushion or dome for the discharge of both ends and the steel ball valves a t each end are accessible without disturbing any piping or removing their seats.
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HEAT TRANSMISSION I N VACUUM EVAPORATOR TUBES. M’Cormack, Dormitzer and Roleson conducted a series of experiments to determine the efficiencies of a Swenson evaporator using tubes of four different materials, namely, copper, steel, lead and tin (Chem. Eng., 16, I). Since it is known that slight variations in the composition of the metal exert considerable influence on the heat conductivity, the tubes tested were analyzed by standard methods. The results show that the efficiency is highest for the copper tubes and next highest for the steel tubes; this is as one would expect, as copper and steel possess a higher coefficient of heat transmission than the other materials used, and also owing to the fact that the copper and steel tubes used were from one-third to one-fourth as thick as the other two sets of tubes. Although the coefficient of heat transmission for tin is greater than that of lead, and although the lead tubes were about one-eighth thicker, the efficiency of the latter was found to be greater. I n general, it may be said that there was found to be very little difference in the efficiencies for the various tubes, the maximum difference being 6.7 per cent. As the authors note, this is doubtless to be attributed to the fact that with tubes of this small thickness the coefficient of heat transmission does not materially effect the efficiency.
A NEW CRUDE OIL ENGINE. The “Blackstone” semi-Diesel type of crude oil engine, described in Gus and Oil Power, 7, 471, is said to be capable of working on all kinds of crude oils, both shale and petroleum, as well as upon petroleum residues, consuming the fuel without leaving any residue and this without the ajd of an abnormally high compression. The fuel is injected into the cylinder by means of compressed air a t 400 pounds, the main air compression in the cylinder being not more than r j o pounds. The fuel charge is ignited by a flame produced by the combustion of a small auxiliary charge of oil injected a t every cycle into a bulb or igniter kept hot by the repeated combustions. The main cylinder fuel spray is regulated by the governor, and the engines run economically on any load. A feature of these engines is the prolonged injection of the main spray fuel; which maintains the initial pressure during a considerable portion of the working stroke, thus ensuring a maximum amount of power with a minimum of cylinder volume. This type of engine is made both stationary and portable, the stationary up to 300 B. h. p. Vertical multi-cylinder engines are also manufactured for marine purposes, driving dynamos, etc. A DOUBLE-OILING SYSTEM PUMP. The “Sterling” double-oiling system pump, described in Power, 36, 103, is designed to handle clean and dirty oil a t the same time. The main casting contains a steel rack plunger which is reciprocated by a gear segment fastened to a shaft extending through the pump and having a t its outer end a lever connected to some moving part of the engine. The operating lever has eight adjusting holes to control the amount of oil pumped, and it is also adjustable on the shaft which it drives so that it may be set a t any angle. I t is therefore possible
AIR- JET CHIMNEY VENTILATOR. A Philadelphfia firm is manufacturing a ventilator system in which the draft is created by an air-jet chimney ventilator, the operating air being produced by a rotary blower which creates a suctioii or negative pressure in the furnace. On the average; the blower consumes 0.5 per cent. of the fuel burned, and a t the heaviest load of the grate I per cent. The combustion gases do not pass through the blower, so repairs and replacements are not expensive. The system is said to considerably increase the capacity, efficiency, and advantages of the superheater and economizer, as but a small quantity of gases of high temperature are utilized in them. With a varying steam consumption, it is claimed that one boiler may be forced for a time without putting extra boilers in operation, and, most important of all the advantages, it is possible to use lowgrade fuels such as lignite, brown coal, etc., in the furnace. THE UTILIZATION OF PEAT. I n 1907, the peat industry of Europe was investigated by the Department of Mines of Canada, and later a report was published in which the European practice was discussed in detail. In order to determine the possibilities of peat fuel for industrial purposes, the Department purchased some 300 acres of peat bog and has been experimenting with the foreign systems. I n the manufacture of air-dried fuel from peat bogs, the peat has been dug by hand, transferred by an elevator into a mill, the resulting pulp conveyed by cable cars to the drying fields, rolled into a sheet about 4 in. thick by a press, and divided by knives into blocks which are then dried on the field. Allowing 140 days for a season’s work, the cost of fuel on the field is said to be $1.40 a ton and when stored in the shed $1.6j per ton. I n Sweden, the cost of a plant for the manufacture of 20,ooo tons of peat powder by the Ekelund system is $86,000, and the cost of producing one ton is $2.30; in Canada, however, the cost per ton is higher, for common labor in Sweden gets a wage of but $1.00to $ 1 . 2 2 per day of IO hours. While peat powder has been found to be satisfactory as a fuel in Sweden, because of the expense of production, waste of available nitrogen, etc., Eugene Haanel, the Director of the Department of Mines of Canada, has concluded, after considerable experimentation, that the proper method is to gasify the peat in a suitable producer, along the lines of the ideas advocated by Frank and Caro, and also applied in Ziegler’s peat gas-producer; and considers that in order to make the peat industry profitable, a 20 hour day, working 2 shifts, must be adopted, as the real season for working a Canadian bog is not over I IO working days a year. Thackara (The Gus Engine, 14, 318) states that the production of gas from peat having a water content up to 20 per cent. for use in suction gas engines has met with considerable success in Germany, but for a number of years efforts have been made to utilize peat with a water content as high as 50 to 60 per cent. and thus eliminate the expensive drying process. I t is now found that peat containing 40 per cent. of water and costing $3.57 per metric ton, may be used with the Gorlitz engine, the consumption per kw.-hr. being 3.43 pounds for one trial and j.31 pounds for another.
