Part 34

BLOCKING AND THINNING.

When the beets are up and show the third leaf they should be “thinned.” Unless thinned at the proper time the pulling up of the superfluous beetlets injures the roots of the remaining ones. Scientific experiments in Germany, where all other conditions were identical, showed that one acre thinned at the proper time yielded 15 tons; the next acre, thinned a week later, yielded 13¹⁄₂ tons; the third acre, thinned still a week later, yielded 10¹⁄₂ tons; and the fourth acre, thinned three weeks after the first, yielded 7¹⁄₂ tons.

The men in the foreground are “blocking” the beets, leaving a bunch of them every eight inches. Those in the rear are “thinning,” or pulling up the superfluous beetlets, leaving one in a place, eight inches apart.]

This field of beets yielded 20 tons to the acre. Ex-Secretary of Agriculture James Wilson is convinced that when American farmers become expert in beet culture they will average to produce more than 20 tons per acre because of the superiority of our soils. The ideal factory beet weighs about two pounds, and a perfect “stand” of such beets, one every eight inches, in rows eighteen inches apart, would yield 43¹⁄₃ tons per acre. The present average yield in the United States is about 10 tons per acre, while the hitherto “worn-out soils” of Germany yield 14 tons per acre, or 40% more than is secured from our “virgin soils.”]

TOPPING THE BEETS.

After the beets are plowed out they are topped or cut off by hand and the tops are fed to stock, for which purpose they are worth $3.00 per acre. They are topped just below the crown and the factories require that they be so topped as to remove any portion which grew above the ground, as such portion of the beet contains but a small percentage of sugar. The beet will grow in length, and, if as a result of shallow plowing or coming in contact with a rock it cannot grow downward, it will grow upward and out of the ground, thus necessitating a deeper topping and consequent loss to the farmer.]

Beets arriving at the factory by rail from receiving stations either are stored in bins until needed or are floated directly to the beet washers. If to be used at once, they are dumped, as shown above, and slide directly into a cement flume filled with warm water, which has been pumped to its upper end, and is flowing in the direction of the beet end of the factory. In whatever manner they may be received, they first are weighed, and as they are dumped, a basket is held under them to catch a fair sample of both beets and the loose dirt, which the car or wagon contains. These samples, properly tagged, are conveyed to the beet laboratory, where they are washed, and trimmed if not properly topped, and the difference in the weight of the sample beets as received and their weight when washed is called the “tare.” Whatever percentage this amounts to is applied to and deducted from the weight of the car or wagon load. A sample of these beets then is tested by the polariscope for its sugar content and its purity; farmers often being paid a stipulated price per ton for a beet of a given sugar content and 25 to 33¹⁄₃ cents per ton additional for each extra degree of sugar which they contain. The tare rooms and the beet-testing laboratories are open to any one, and in some localities the farmers’ associations employ experts to tare and analyze each sample of beets.]

FACTORY BEET BINS FILLED TO CAPACITY.

As they arrive by rail from receiving stations, or by team, or traction engines from the farm, beets are stored in bins or sheds, the capacity of which ranges from 6000 to 35,000 tons per factory, depending upon location and general climatic conditions.

The bins are V shaped, about 3 feet wide at the bottom, 20 to 30 feet at the top, and they are 20 to 30 feet high. As beets are needed, beginning at one end of the bin the loose three-foot planks at the bottom are removed one at a time, and with hooks attached to long poles the beets are rolled into the flume or cement channel below, in which they are floated into the factory. This is not only to save labor, but to loosen up the dirt which attaches to the beets, thus partially washing them. The water which is used in the flumes is warm water from the factory.]

These factories cost from half a million to three million dollars. They consume from 500 to 3,000 tons of beets per day, and during the “campaign,” which usually lasts about three months, will produce from 12 to 75 million pounds of granulated sugar. There are 73 of these factories, located in 16 States, from Ohio to California. During the operating season they give employment to from 400 to 1000 men each.]

CHEMICAL LABORATORY.

In a beet-sugar factory each set of apparatus for performing a given process is termed a “station.” In the chemical laboratory the juices and products from each station are tested hourly to check up the correctness of the work and to determine the losses of sugar in each process in the factory.]

After being floated in from the sheds the beets are elevated from the flume to a washer, where they are given an additional washing before being sliced. From the washer they are elevated and dropped into an automatic scale of a capacity of 700 to 1500 pounds. From the scale they pass to the slicers, where with triangular knives they are cut into long, slender slices, which look something like “shoestring” potatoes. These slices drop through the upright chute seen at the right side of the picture, and are packed tightly into cylindrical vessels holding from two to six tons each; the battery consisting of eight to twelve vessels arranged either in a straight line or in circular form. Warm water is run into these slices, and coaxes out the sugar as it passes from one vessel to the succeeding ones. After passing through the entire series of vessels the water has become rich in sugar, of which it contains from 12 to 15 per cent, depending upon the richness of the beets. It then is drawn off and is called diffusion juice or raw juice. This is carefully measured into tanks and recorded. As this juice is drawn off the vessel over which the water started is emptied of the slices from the bottom, the exhaust slices containing in the neighborhood of ¹⁄₄ to ¹⁄₃ per cent of sugar. These slices are carried out from the factory in the form of pulp and fed to stock, as explained later.]

CARBONATATION AND SULPHUR STATION.

Warm raw juice is drawn into the carbonatation tanks and treated with about 10 per cent milk of lime--about like ordinary whitewash. This lime throws out impurities, sterilizes the juice and removes coloring matter. Carbonic acid gas from the lime kiln is forced through the lime juice in the tank, throwing out the excess of lime, converting it into a carbonate of lime or chalk. Tests are taken here by the station operator to show when the process is finished.]

From the carbonatation tanks the juice is pumped or forced through filter presses consisting of iron frames so covered with cloth that the juice passes through the cloth as a clear liquid, leaving the lime and impurities precipitated by it, in the frame, in the form of a cake. This cake, after washing, is dropped from the presses and conveyed out of the factory. It contains from one to two per cent of its weight in sugar, which constitutes one of the large losses of the process. It also contains organic matter, phosphate and potash, besides the carbonate of lime, which makes it an excellent fertilizer, all of which is used in Europe on the farm, but so far to too small an extent in America.]

EVAPORATORS.

After a second, and sometimes a third carbonatation and filtration, the juice is carried to the evaporators, commonly called the “effects,” usually four (4) large air-tight vessels furnished with heating tubes running from 3000 to 7000 square feet in each vessel. A partial vacuum is maintained in these evaporators which makes the juice boil out at a low temperature, thus preventing discoloration, and to a large degree the destruction of sugar which will come about by high temperature. There always is, however, some unavoidable loss of sugar in this apparatus. The juice passes along copper pipes from first to last vessel, becoming thicker as it does so. It comes into the first vessel at 10% to 12% sugar and is pumped out of the last one so thick that it contains about 50% of sugar.]

After a careful filtration, the juice that comes from the evaporators, and is called thick juice, is pumped to large tanks high up in the building, and from these is drawn into vacuum pans. These are large cylindrical vessels from 10 to 15 feet in diameter and from 15 to 25 feet high, with conical top and bottom, built air-tight. Around the inner circumference they are furnished with 4- to 6-inch copper coils, which have a heating surface of 800 to 2000 square feet. Exhaust steam is used in the evaporators, live steam in the pans, the juice in both being boiled in a vacuum to prevent discoloration and reduce losses.

After considerable thickening by this evaporation, minute crystals begin to form. When sufficient of these have formed, fresh juice is drawn in and the crystals grow, the operator governing the size of the crystals to suit the trade. If small crystals be desired, a large quantity of juice is admitted at the outset, while if large crystals are desired, a small quantity of juice first is admitted, and, as it boils to crystals, fresh juice gradually is added to the pan, and the crystals are built up to the desired size. The operator of this pan, known as the “sugar boiler,” is one of the must important men in the factory. The water furnished the condensers of these vacuum pans and the evaporator goes to the beet sheds and is used for floating in the beets. It amounts to from 3,000,000 to 8,000,000 gallons every 24 hours, depending upon the size of the factory, and must be very pure.]

FRONT VIEW OF CENTRIFUGAL MACHINES.

The mass of crystals with syrup around them and containing about 8 per cent to 10 per cent of water is let out of the vacuum pan into a large open vessel called a mixer, beneath which are the centrifugal machines. These are suspended brass drums perforated with holes and lined with a fine screen. They are made to revolve about 1000 times to a minute, and the crystal mass of sugar rises up the side like water in a whirling bucket. The centrifugals force the syrup out through the screen holes, leaving the white crystals of sugar in a thick layer on the inner surface. These are washed with a spray of pure warm water and then are ready for the dryer.]

The damp white crystals from the centrifugal machine are conveyed to horizontal revolving drums about 25 feet long by 5 to 6 feet in diameter. These drums are furnished with paddles on the inside circumference, the paddles picking the sugar up and dropping it in showers as the drum revolves. Warm dry air is drawn through and takes the moisture out of the sugar, which now is ready to be put in bags or barrels for the market.]

CRYSTALLIZERS.

The syrup that was thrown off from the crystals in the centrifugal machines is taken back to the vacuum pan, evaporated in the same manner as previously described, and from the vacuum pan goes into the crystallizers to carry the process of crystallization as far as it will go. These contain from 1000 to 1600 cubic feet of the crystallized mass which remains in them from 36 to 72 hours, during which time it is kept in constant motion by a set of slowly revolving paddles, or arms, to facilitate further crystallization. From the crystallizers it goes to the centrifugal machines, where the syrup is separated from the crystals as before. The crystals are remelted and go in with the thick juice for white sugar. The syrup, still containing a large amount of sugar, goes out to be sold as cattle feed or to an Osmose or Steffens process, where a portion of the remaining sugar may be recovered. This lost syrup constitutes the largest loss in the entire process. It contains all the impurities of the beet juice not removed by the lime. These impurities prevent more than one and one-half times their weight of sugar from crystalizing, and make what is called molasses.]

For a century the high feeding value of sugar-beet pulp has been recognized in Europe, but until a few years ago millions of tons of this valuable by-product rotted about American beet-sugar factories, as shown above, because American farmers could not be made to believe it possessed sufficient value to pay for hauling it back to the farm.]

SACKING ROOM.--SHOWING AUTOMATIC SCALES AND SEWING MACHINE.