Scientific American Supplement, No. 832, December 12, 1891

Chapter 2

Chapter 24,142 wordsPublic domain

Several sodic-baryta methods have been recently invented. Of these we will mention one where 1/4000 to 1/2000 part of calcined soda is added to the beet slices in diffusors. The juice when drawn from the battery is heated to 154° F., and defecated with hydrate of baryta and milk of lime. Nearly all foreign substances are thus eliminated. Carbonatation then follows.

Government taxation upon the sugar industry is destined within a few years to be withdrawn. The new law recently put into operation no longer taxes beets worked at factory, but the sugar manufactured. The rate of taxation is about 2 cents per pound on all sugar made.

Recent data from northeast Germany give the work during campaign 1890-91 of 54 associated beet sugar factories. They used 2,130,000 tons beets, obtained from 142,602 acres of land, average yield 12 tons. The total sugar amounted to 251,000 tons, of which 241,000 were from beets and 10,000 tons from molasses worked by special processes. The polarization of beet juices averaged 13.09; _masse cuite_, 14.31; extraction of sugar of all grades, 11.79. It required 848 lb. beets to produce 100 lb. sugar.

In every center where beet sugar is made there exists some local society; each year members from these societies meet to exchange views upon the sugar situation of the empire.

Of late, there has been a general complaint respecting quality of sugar sold on the Magdeburg market. At one time the sugars averaged more organic substances than ash; now there is more ash than organic substances. Such sugars are most difficult to work, and cause much loss of time in centrifugals.

The most desirable temperature for diffusion batteries is not yet definitely settled. Some manufacturers recommend 82° to 86° F. On the other hand, satisfactory results have been obtained at 145° F., followed by cold water in the diffusors.

The use of hydrofluoric acid, even in small quantities to prevent fermentation, should not be allowed.

It is proposed to use hydrogen dioxide for saccharine juice purification. The alkalinity of juice is reduced to 0.07 by a judicious use of lime. Precaution must be taken to keep the temperature at 87° F. After a preliminary filtration about 4 per cent. hydrogen dioxide is added. The whole is then heated to the boiling point, after which ½ to 1 per cent. lime is added. When alkalinity of filtrate is 0.03 phosphoric acid and magnesia are added, in quantities representing 0.03 per cent. of sugar in juice for magnesia, and 0.6 per cent. for the phosphoric acid. In working beet juices hydrogen dioxide may be used in the diffusor or during any phase of the sugar manufacturing process, even upon sugars in centrifugals. In all cases the results obtained are said to be most satisfactory.

A method to crystallize the sugar contained in the mother liquor of a _masse cuite_ consists in mixing during 24 hours the hot product, direct from the pan, with low grade molasses. Gradual cooling follows. The crystals of _masse cuite_ effect a crystallization of the otherwise inactive product contained in the molasses. The separation of crystals from adhering molasses is done in a special washing appliance arranged in battery form.

It has been frequently asked if the existing and accepted formula for determining in advance the amount of refined sugar that may be extracted from either beets, _masse cuite_ or raw sugar, is to be considered exact, without special allowance being made for raffinose. An intelligent discussion upon the subject shows that the sugar in question, whether present or not, in no way influences the formula under consideration.

AUSTRIA-HUNGARY.

The committee on exhibition at Prague has issued several interesting pamphlets, from which we learn that in Bohemia, in 1819, there existed one beet sugar factory. In 1890 the total number of factories was 140; last year 370,000 acres were planted in beets, and the yield was 3,700,000 tons; yield of sugar averaged 2,700 lb. per acre; 40,000 hands were employed. During the past 24 years 17,900,000 tons of coal have been consumed, and the working capacity per factory is now far greater than formerly. There are at present seven sugar refineries in Bohemia.

Commercial arrangements with Germany having terminated favorably, great pressure is being brought to bear upon Italy, Roumania, Servia and Switzerland, to induce them to enter into a treaty. Sugars imported by the country last named were 35,892 tons in 1889 and 43,300 tons during 1890.

BELGIUM.

If fresh cossettes are fed to cows, in quantities per diem representing 20 per cent. of the animal's weight, they have a thinning effect. When the refuse has been siloed for eight months, and 12 per cent. of the animal's weight is used, there will follow a slight daily increase in weight. Better results may be obtained from cossettes that have been kept for two years; with the latter, if cows eat only 7 per cent. of their weight, considerable fattening follows. Consequently, while beet refuse, after long keeping, loses 50 per cent. of its weight, it appears in the end to be more economical for feeding purposes than fresh cossettes direct from the battery.

During this period of keeping the percentage of water remains nearly constant; fatty substances which were 0.08 per cent. become 0.74; and the percentage of carbohydrates diminishes. Chemists are unable to explain the changes that have taken place; if they are desirable, as they appear to be, judging from the practical results just cited, there is this question to be solved: What future have dried cossettes? Evidently they offer advantages, as no one can doubt, such as a decrease in weight and bulk, easy keeping for an indefinite time, etc. At present, there is building a silo to contain 4,000 tons fresh cossettes; this is to have the best possible system of drainage. During the coming season it is proposed to analyze the water draining from this mass of fermenting refuse; and we may then learn more than we now know about the chemical changes above mentioned.

A correspondent of M. Sachs asks why it is not possible to use live steam in defecating tanks. A simple calculation shows that the water to be subsequently evaporated would be increased 10 per cent. This evaporation would cost more than cleaning of copper coils, etc., combined with other difficulties existing appliances offer.

The question as to the most desirable number of beets necessary to analyze to obtain an average has been in part settled. Factories working 500 tons per diem should make at least 200 analyses of beets received, which work offers no difficulty by the rapid methods now used. Several samples should be taken from every cart load delivered, then make average selections from the same.

RUSSIA.

Weak currents of electricity, 0.03 to 0.04 ampere, have been passed through sirups for fourteen hours without any special increase in purity coefficient. Experiments made upon diluted molasses or with raw beet juices were not encouraging.

Mixing of filter press scums with diffusion juices is said to offer special advantages for the preliminary purification. Not over one to two per cent. of scums should be used. If in too great quantity, the raw juices will yield inferior results. During operations that follow, experiments are not yet sufficiently advanced to determine with certainty within what limits the refuse scum utilization process is to be recommended. We have great doubts as to the wisdom of introducing foreign elements, eliminated from other juices in a previous operation, into a juice fresh from the battery.

OTHER COUNTRIES.

The beet sugar factory in Japan is said to be working with considerable success.

This year in Europe over 3,000,000 acres are devoted to beet cultivation. If the yield averages 12 tons, the crop of roots to be worked during campaign 1891-92 will certainly not be less than 36,000,000 tons, with a total yield of first grade sugar of about 7,300,000,000 lb.

Sugar sells for 9 cents per pound in Persia, where Russia has almost a monopoly of that business.

Finland imported, during 1889, 9,416 tons sugar, valued at $1,000,000. Germany supplied two-thirds of this at cheaper rates than Russia, owing to facilities of transportation. Two refineries are working; one of these uses exclusively cane sugar, while the other employs both cane and beet sugar.

A beet sugar factory in England, that has been idle for many years, is to resume operations under a new company, adopting the plan of growing a sufficient quantity of beets for an average campaign, independently of what all the farmers of the locality propose to do.

Siberia is to have a beet sugar factory. Experiments in beet cultivation have shown excellent beets may be raised there. Special advantages are offered by the Russian government, and factories are to be exempt from taxation daring a period of ten years. Sugar in Siberia is now considered an article of luxury, owing to distance and difficulties of transportation from manufacturing centers.

A special delegation from Canada has been sent to Europe, to study and subsequently report upon the true condition of the beet sugar industry.

A correspondent writes from Farnham, Canada, that the Canadian government grants a bounty of 2 cents per pound on beet sugar during campaign 1891-92. Duties on raw sugar were abolished last June.

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AMERICAN WORKSHOPS.

An interesting paper on some of the leading American workshops was lately read before the members of the Manchester Association of Engineers on Saturday by Mr. Hans Renold. After expressing his opinion that the English people did not sufficiently look about them or try to understand what other nations were doing, Mr. Renold stated that he had visited that portion of America known as New England, and the works he had inspected were among the best in the United States. Among the many special features he had noticed he mentioned that in a Boston establishment where milling machine cutters were made he had found that £1 spent in wages produced as much as £30 to £40 worth of goods, the cutters being made at the rate of about sixty-four per hour by about a dozen men. Another noticeable feature was the exceptional care taken in storing tools in American workshops. These, in fact, were treated as if they were worth their weight in gold; they were stored in safes much in the same manner as we in England stored our money. He was, however, impressed by the fact that the mere understanding of the method of American working would not enable them to do likewise in England, because the American workmen had gone through a special training, and a similar training would be necessary to enable English workmen to adapt themselves to American machines. One very noticeable feature in American engineering shops which he visited was that all the machine men and turners were seated on blocks or stools at their machines, and the question naturally arose in his mind what would English engineers say if such a practice were adopted in their shops. In other ways he was also struck by the special attention devoted to the comfort of the workmen, and he was much impressed by the healthy condition of the emery polishing shops as compared with similar shops in this country. In England these shops in most cases were simply deathtraps to the workmen, and he urged that the superior method of ventilation carried out in the States should be adopted in this country by introducing a fan to each wheel to take away the particles, etc., which were so injurious. One very special feature in the United States was that works were devoted to the manufacture of one particular article to an almost inconceivable extent, and that heavy machine tools complete and ready to be dispatched were kept in stock in large numbers. American enterprise was not hampered as it too frequently was in England by want of capital; while in England we were ready to put our savings in South American railways or fictitious gold mines, but very chary about investing capital which would assist an engineer in bringing out an honest improvement, in America, on the other hand, it was a common practice among the best firms to invest their savings over and over again in their works, which were thus kept in a high state of perfection.

The above paper came in for some pretty severe criticism. Mr. John Craven remarked that although Mr. Renold had gone over a wide field of subjects, he had practically confined his remarks to Messrs. Brown & Sharpe's establishment, and while he (Mr. Craven) was ready to admit that so far as high class work and sanitary arrangements were concerned, Messrs. Brown & Sharpe's were a model, they could not be put forward as representative of American establishments generally. As a matter of fact, many of the American workshops were not as good as a large number of similar workshops in Manchester. Mr. Renold had referred to the extensive use of gear cutters in the United States, but he might point out that it was in Manchester that the milling machine was first made. Mr. Samuel Dixon said he had certainly come to the conclusion that no better work was done in America than could be and was being done in this country; while as regards the enormous production of milling cutters, that was simply an example of what could be done where large firms devoted themselves to the production of one specialty. With regard to the statement made by Mr. Renold that the American thread was preferable to the Whitworth thread, he might say he entirely disagreed with such a conclusion, and he might add that after visiting a variety of Continental and American workshops he should certainly not, if he were called upon to award the palm of superiority in workmanship, go across the Atlantic for that purpose. Mr. J. Nasmith remarked that whether English engineers were the inventors of the milling machine or not, it must be admitted that it was through this type of cutter being taken up by the Americans that milling had become the success it was at the present time. English engineers were very conservative, and it was only through the pressure of circumstances that milling machines came into general use in this country. When American inventions were brought to England they were generally improved to the highest degree, but he thought the chief fault of both American and Continental engineers was what one might call "over-refinement;" there was such a thing as over-finishing an object and overdoing it. If, however, American machinery was so much superior to what we had in this country, as asserted by the reader of the paper, how was it that cotton machinery, with all its intricacies, could be sent to the United States, in the face of American manufacturers, even though the cost was increased from 40 to 60 per cent.? At the present time it was possible for English machinists to secure contracts for the whole of the machinery in an American mill, and inclusive of freight charges and high tariff, deliver and erect it in America at a lower cost than American engineers with all the advantages of their immeasurably superior tools were able to do. Another speaker, Mr. Barstow, ridiculed the idea that the Americans could be so pre-eminent in the manufacture of emery wheels as might be inferred from Mr. Renold, when they had before them the fact that from the neighborhood of Manchester thousands of emery wheels were every year exported to the United States.

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MODERN METHODS OF QUARRYING.

Mr. Wm. L. Saunders, for many years the engineer of the Ingersoll Rock Drill Co., and hence thoroughly familiar with modern quarrying practice, read a paper before the last meeting of the American Society of Civil Engineers on the above subject, containing many interesting points, given in the _Engineering News_, from which we abstract as follows.

As a preliminary to describing the new Knox system of quarrying, which even yet is not universally known among quarrymen, Mr. Saunders gives the following in regard to older methods:

The Knox system is a recent invention; no mention was made of it in the tenth census, and no description has yet been given of it in any publications on quarrying. The first work done by this method was in 1885, and at the close of that year 2 quarries had adopted it. In 1886 it was used in 20 quarries; in 1887 in 44, in 1888 in upward of 100, and at the present time about 300 quarries have adopted it. Its purpose is to release dimension stone from its place in the bed, by so directing an explosive force that it is made to cleave the rock in a prescribed line without injury. The system is also used for breaking up detached blocks of stone into smaller sizes.

Quarrymen have, ever since the introduction of blasting, tried to direct the blast so as to save stock. Holes drilled by hand are seldom round. The shape of the bit and their regular rotation while drilling usually produce a hole of somewhat triangular section. It was observed, many years ago, that when a blast was fired in a hand-drilled hole the rock usually broke in three directions, radiating from the points of the triangle in the hole. This led quarrymen to look for a means by which the hole might be shaped in accordance with a prescribed direction of cleavage.

The oldest sandstone quarries in America are those at Portland, Conn. It was from these quarries that great quantities of brownstone were shipped for buildings in New York. The typical "brownstone front" is all built of Portland stone. As the Portland quarries were carried to great depths the thickness of bed increased, as it usually does in quarries. With beds from 10 to 20 ft. deep, all of solid and valuable brownstone, it became a matter of importance that some device should be applied which would shear the stone from its bed without loss of stock and without the necessity of making artificial beds at short distances. A system was adopted and used successfully for a number of years which comprised the drilling of deep holes from 10 to 12 in. in diameter, and charging them with explosives placed in a canister of peculiar shape. The drilling of this hole is so interesting as to warrant a passing notice. The system was similar to that followed with the old fashioned drop drill. The weight of the bit was the force which struck the blow, and this bit was simply raised or lowered by a crank turned by two men at the wheel. The bit resembled a broad ax in shape, in that it was extremely broad, tapering to a sharp point, and convex along the edge.

Fig. 1 illustrates in section one of the Portland drills, and a drill hole with the canister containing the explosive in place. The canister was made of two curved pieces of sheet tin with soldered edges, cloth or paper being used at the ends. It was surrounded with sand or earth, so that the effect of the blast was practically the same as though the hole were drilled in the shape of the canister. In other words, the old Portland system was to drill a large, round hole, put in a canister, and then fill up a good part of the hole. Were it possible to drill the hole in the shape of the canister, it would obviously save a good deal of work which had to be undone. The Portland system was, therefore, an extravagant one, but the results accomplished were such as to fully warrant its use. Straight and true breaks were made, following the line of the longer axis of the canister section, as in Fig. 2.

It was found that with the old Portland canister two breaks might be made at right angles by a single blast, when using a canister shaped like a square prism. In some of the larger blasts, where blocks weighing in the neighborhood of 2,000 tons were sheared on the bed, two holes as deep as 20 ft. were drilled close together. The core between the holes was then clipped out and large canisters measuring 2 ft. across from edge to edge were used.

In regard to another of the older systems of blasting, known as Lewising, Mr. Saunders says:

A Lewis hole is made by drilling two or three holes close together and parallel with each other, the partitions between the holes being broken down by using what is known as a broach. Thus a wide hole or groove is formed in which powder is inserted, either by ramming it directly in the hole, or by puling it in a canister, shaped somewhat like the Lewis hole trench. A complex Lewis hole is the combination of 3 drill holes, while a compound Lewis hole contains 4 holes. Lewising is confined almost entirely to granite. In some cases a series of Lewis holes is put in along the bench at distances of 10 and 25 ft. apart, or even greater, each Lewis hole being situated equidistant from the face of the bench. The holes are blasted simultaneously by the electric battery.

After noting another system used to a limited extent, and not to be commended, viz., the use of inverted plugs and feathers (the plugs and feathers being inserted as a sort of tamping which the blast drives upward to split the rock), Mr. Saunders continues in substance as follows:

It is thus seen that the "state of the art" has been progressive, though it was imperfect. Mr. Sperr, in his reference to this subject, made in the report of the tenth census, says: "The influence of the shape of the drill hole upon the effects of the blast does not seem to be generally known, and a great waste of material necessarily follows." This was written but a few years before the introduction of the new system, and it is doubtless true that attention was thus widely directed to the conspicuous waste, due to a lack of knowledge of the influence of the shape of a drill hole on the effect of a blast. The system developed by Mr. Knox practically does all and more than was done by the old Portland system, and it does it at far less expense. It can best be described by illustrations.

[Illustrations: Figs. 3, 4, 5, 6]

Fig. 3 is a round hole drilled either by hand or otherwise, preferably otherwise, because an important point is to get it round. Fig. 4 is the improved form of hole, and this is made by inserting a reamer, Figs. 5 and 6, into the hole in the line of the proposed fracture, thus cutting two V-shaped grooves into the walls of the hole. The blacksmith tools for dressing the reamers are shown in Fig. 7. The usual method of charging and tamping a hole in using the new system is shown in Fig. 8. The charge of powder is shown at C, the air space at B and the tamping at A. Fig. 9 is a special hole for use in thin beds of rock. The charge of powder is shown at C, the rod to sustain tamping at D, air space at BB, and tamping at A.

Let us assume that we have a bluestone quarry, in which we may illustrate the simplest application of the new system. The sheet of stone which we wish to shear from place has a bed running horizontally at a depth of say 10 ft. One face is in front and a natural seam divides the bed at each end at the walls of the quarry. We now have a block of stone, say 50 ft. long, with all its faces free except one--that opposite and corresponding with the bench. One or more of the specially formed holes are put in at such depth and distance from each other and from the bench as may be regulated by the thickness, strength and character of the rock. No man is so good a judge of this as the quarry foreman who has used and studied the effect of this system in his quarry. Great care should be taken to drill the holes round and in a straight line. In sandstone of medium hardness these holes may be situated 10, 12 or 15 ft. apart. If the bed is a tight one the hole should be run entirely through the sheet and to the bed; but with an open free bed holes of less depth will suffice.