Lime-Barium Softener for Treatment of Boiler Feed Water Description of a Successful Water-Softening Installation for the Production of Sulphate-Free Boiler BY C. A. MEHRING T HE method of softening water for boiling purposes by the lime-barium treatment has been carried on with considerable success for the past two years at the Chino Copper Co.'s plant at Hurley, N. M. The softeners used are manufactured by the Reisert Automatic Water Purifying Co. of New York. The apparatus consists of a raw water tank, a settling tank with gravel and filter embodied, a lime slacking tank, a saturator and sludge tank. The raw water is admitted to the plant through a float valve at the end of the raw water pipe E-1. Through this valve the water is discharged into the small compartment of the raw water tank. The float valve is controlled by a float in the settling tank, or a filter compartment, which is raised or lowered in proportion to the amount of soft water drawn off. From the small compartment the water passes through a rectangular weir into the large siphon compartment. Through this siphon the water is discharged into a siphon discharge tank riveted to the bottom of the raw water tank. The air which accumulates here escapes through vent Y. From the discharge tank the water flows intermittently through pipe D, D-1 to the bottom of the outer, or lime, cone. THE LIME SATURATOR The lime saturator is a cone-shaped tank, consequently all suspended matter and precipitate settle to the bottom and can be drawn off through cock R to sewer. The suspended matter and precipitate are due to the make-up of the raw water and insoluble calcium carbonate in the lime. The required amount of lime for the saturator is slacked in the slacking tank by the addition of just enough water to make the consistency of cream. This lime is added to the saturator through cock H-1 and pipe H into the bottom of the saturator. The raw water from the raw water tank is admitted to the saturator through a rectangular weir J-1 and pipe J. This water entering the bottom of the saturator comes in contact with the cream of lime and on its way to the lower cone through pipe K, K-1 and K-2 becomes saturated with lime. This lime water meets the raw water at the bottom of the lower cone, removing the temporary hardness. The precipitates settle out and sink to the bottom of the cone. From here they are drawn off through cock and pipe N to sewer. The water then rises from the lower cone and enters the inner, or barium, cone, through pipe C, which has the same diameter as the siphon pipe. The speed of the water flow is very high, consequently the barium carbonate is thoroughly stirred up so that it comes into intimate contact with the water, removing the sulphates. The reactions take place in the water on its way to the top of the inner tank. Here the area is greatly increased, hence the speed of the water is materially decreased, allowing the precipitate of barium sulphate to settle and sink to the bottom of the inner cone. Therefore most of the precipitate is removed before the water reaches the holes near the top of the main tank. Through these holes the water flows into the outer annular space which contains the filter. THE FILTER The filter consists of a perforated plate, a brass screen, 6 in. of gravel and 16 in. of sand. The softened and filtered water is collected in a triangular space below the filter bottom. From here it is drawn off through pipe B and B-1, in which pipe line a shut-off valve is provided to prevent the raw water from entering softened water storage tank while the filters are being washed. This pipe is raised sufficiently above the sand so that should the raw water be shut off entirely, the water will not be lowered below the sand on the filter. In the space below the filter bottom is an annular perforated pipe G for the air wash. For an even distribution the air is admitted at four points. This is also the case with the wash water pipe E, which connects with the raw water pipe E-1. Above the sand four semi-circular baffles are provided at the end of pipe A. These baffles prevent any sand from being washed over through pipe A-1, A-2 to sewer while filters are being washed. METHOD OF CHARGING SOFTENERS AND WASHING FILTERS The valve 5 at the end of the raw water pipe E is closed, preventing any water from entering the softener. Cock R is opened, sludging out the lime saturator. This cock is left open until the heavy precipitate is all washed out, or until the water becomes almost clear. Cock N is opened, allowing the sludge from the lower, or lime, cone, to flow to the sewer. This cock is left open until the water is almost clear. Cock M is opened, allowing the precipitate of barium sulphate and unused barium carbonate to flow into the sludge tank. From this tank it is forced back into the lower, or lime, cone, by means of a steam injector. Valve 1 is closed, shutting off the water through pipe B, thus preventing its entering the soft water storage tank. Valve 4 is opened cautiously, as this is the high pressure air which escapes through the perforated annular pipe under the sand and gravel of the filter. Care must be taken not to agitate too violently, lest sand and gravel become mixed. The action of the air loosens the precipitate which has adhered to the sand and gravel of the filter. Valves 2 and 3 are then opened. Valve 3 allows the raw water to rise through the filter-bed, washing all precipitate, loosened by the action of the air through valve 2 and filter sludge pipe, to sewer. When filter is sufficiently washed, valves 4, 3 and 2 are closed, and valve 1 opened, allowing softened water to flow to storage tank when softener is again in operation. The required amount of barium carbonate is then charged to the barium cone through the barium funnel. The lime in the lime slacking tank, which has been slacked to creamy consistency, is charged to the bottom of the lime saturator through cock H-1, and pipe H. Valve 5 is opened, allowing the water to flow to the siphon tank. The float on this valve automatically controls the operation of the softener for the remainder of the shift. The operation of charging, The operation of charging, sludging and washing filters is performed every 12 hours. METHOD OF COLLECTING SAMPLES All water samples are drip samples taken by means of in. pipes connected at various places on the softeners: The raw water connected on pipe E-1; the saturated lime water on pipe K-2 in the lower, or lime, cone; the softened or treated water on the triangular space below the filter bottom. These drip samples cover a period of 12 hr., at the end of which time they are analyzed. At the end of sludge pipe N a sample is taken at time of sludging and analyzed for barium carbonate. This is done as a precaution against an undercharge or overcharge. 7. Sulphates of Iron, Aluminum, Magnesium, etc., Classed as Magnesia.-Boil solution from determination No. 1 in a covered beaker 15 min., add 25 cc. saturated lime water and allow to stand near boiling temperature 15 min. Filter, wash and titrate all of filtrate with N/25 H,SO, using methyl orange indicator. Cc. acid used X. Run blank in same manner, using distilled water with cc. acid Y. Then (Y— X) 1.17 = mag' nesia, etc., in grains per gallon. = 2CaCO + 2H2O FeH2(CO3)2 +Ca(OH)2: 2 = FeCO, + CaCO, + 2H2O(4) FeSO. Ca(OH), 2 = Fe(OH)2+ CaSO. Fe (SO) + 3Ca(OH), = 2Fe(OH), + 3CaSO. Al (SO.), + 3Ca(OH)2 Ca(OH), = Mg(OH), + CaSO. CaSO,+BaCO, BaSO. + CaCO3 Al (SO.) + 3BaCO, + H2O = BaSO. + Al(OH)3 + 3CO2 (3) (5) (6) (7) (8) (9A) (10) Fe(OH). + 2BaSO. (11) Fe2(SO.). + 3BaCO1 2Fe2(CO3)3 + 3BaSO. (12) (13) CuSO. + BaCO, CuCO. + BaSO. H2SO. BaCO, BaSO. + H2O + CO, (14) (15) 1 cc. is equivalent to 0.005 grain CaCO, Standard N/10 (Na,CO, and NaOH equal parts), called soda reagent. 1 cc. is equivalent to 0.0005 grain CaCO, 1. Alkalinity to Methyl Orange.-Titrate 100 cc. of water with N/25 H,SO,, using methyl orange indicator. Cc. of acid used times 1.17 equals the alkalinity to methyl orange in grains per gallon. Alkalinity to Phenolphthalein.-Titrate 100 cc. of water with N/25 H,SO,, using phenolphthalein indicator. Cc. of acid used times 1.17 equals the alkalinity to phenolphthalein in grains per gallon." 3. Free Carbon Dioxide.-Titrate 100 cc. of water with N/25 Na,CO,, using phenolphthalein indicator. The first faint tinge of pink is the end point. Cc. of Na,CO, used times 1.17 equals the free CO, in grains per gallon. 4-5. Permanent or Negative Hardness.-Boil 100 cc. of water 10 min., add 5 cc. N/10 "soda reagent." Boil further to volume. Filter, wash and titrate all of the filtrate with N/25 H,SO,, using methyl orange indicator [(5 cc. "soda reagent" times 2)—cc. acid used] times 1.17 equals permanent hardness if plus, or negative hardness if minus, in grains per gallon. 6. Temporary Hardness.-Temporary hardness is equal to the methyl orange alkalinity minus the negative hardness. FeSO,, Fe, (SO,),, Al, (SO),, CuSO, H,SO,, etc., are occasionally found in boiler waters. These impurities are precipitated by BaCO,. METHOD OF SETTING WEIR TO LIME SATURATOR On the raw water compartment of the siphon tank are two rectangular weirs J-1 and J-2. J-2, the larger weir, is 3.5 in. wide. J-1, the small weir, is 1.25 in. wide. The two weirs are at the same height from the bottom of the raw water box, hence a proportionate amount of water may be discharged through each. Method of setting weir J-1 to lime saturator so that the required amount of saturated lime water may be discharged from the saturator to the lower, or lime, cone of softener. The raw water must be analyzed at the beginning of each shift to find the required amount of lime to be added to the saturator. For example: Free CO2 0.28 1.51 CONTROL WEIRS ON RAW WATER TANK water can be treated satisfactorily in this type of soft ener. Before the installation of this softener, trouble was experienced due to priming and foaming of the boilers and to a large amount of very hard scale which was difficult to remove, but since the operation of this plant these troubles have been eliminated. New Metal Alloy During the war an Italian engineer, Adolfo Pouchain, after a series of experiments succeeded in producing a new alloy of zinc and copper, which has been given the name "biakmetal." This alloy quickly demonstrated its usefulness in Italian industry, and by reason of its special qualities promises to attain similar success throughout the world. Biakmetal has aroused considerable interest in Italy. A certain large manufacturer has said that his metallurgists have made every effort to determine its exact composition, but without success. From a small beginning the demand for biakmetal has increased to such an extent that a new company, the Stabilimenti Biak, S. A., of Turin, having a capital of 12,000,000 lire ($2,316,000), has been formed to carry on its manufacture. The industrial value of a product which is stronger than steel and less corrosive than copper is evident, and it is claimed that biakmetal, which has passed the experimental stage, possesses these qualities. The most important characteristics are stated to be as follows: (1) The highest known breaking point; (2) the highest limit of elasticity; (3) perfect homogeneity; (4) high resistance to thermic action; and (5) high resistance to chemical action. Biakmetal is extremely well adapted for almost any kind of manipulation. It can be successfully cast, turned, drawn, forged, rolled and stamped. While its development is still in progress, it has already proved especially useful in aëronautic and marine construction on account of its light weight, its unusual strength and its anti-corrosive qualities. In its different forms it may be substituted for steel, brass and aluminum, and for certain uses has important advantages Operation of a Gas Producer BY J. S. MCCLIMON* OST articles on gas producer operation consist of Malon a discussion of theoretical conditions or chemi cal reactions. It is the aim of this article to reduce the causes and effects of these things to a rule-of-thumb method which will be of assistance to the operator or superintendent and may be applied to everyday operating conditions met with in producer practice. STARTING THE PRODUCER A new producer, before being started, should be dried out several days with small fires. This is a precaution which, if properly carried out, will add considerably to the life of the lining. After the producer has been thoroughly dried, all large pieces of wood likely to cause trouble should be removed and the producer filled with ashes to a depth of at least 12 in. over the top of the blower. It is best that a few large clinkers be placed around the openings of the blower to keep them from becoming clogged with fine ashes. These ashes are necessary to protect the metal parts of the producer. They also act as a diffusing medium to distribute the blast over the entire fuel bed, thus insuring even combustion. To start the producer, it is necessary only to level off ashes, throw in several armfuls of small dry wood, saturate with kerosene, and light with a piece of waste. After the wood has burned for a few moments, turn on about 10-lb. blast and blow until the wood is well ignited. A small amount of coal can then be dumped and the fires be built up gradually. Care should be taken that the coal is not fed too fast. Allow a good bed of coke to be formed before any attempt is made toward crowding the operation of the producer. One should remember that it takes several hours to get a producer fire built up properly to the point where it is making good gas. No special attempt need be made at this point to get the fire distributed over the entire fuel bed. It will spread of itself later, and it is usually better to have a good fire at one point than several small ones scattered over a larger area. In case it is necessary to stop the producer at any time, the blast should be turned off immediately and never exceed 10 lb. during this idle period. THREE ZONES The various zones of the producer are shown in Fig. 1. It can be seen that there are three-the ash, the incandescent or the fire zone, and the green coal zone, the last consisting of coal which has not received a sufficient amount of air to become incandescent. This is also termed the distillation zone. The existence of these three zones is a point often overlooked in the operation of the producer. MEASURING FIRES The usual method of measuring the fires is for the foreman to take a rod about 5 ft. long, which he inserts in one of the poke-holes in the producer top until he establishes the height of the fuel bed. This method is totally inadequate, because no attention is given to the depth of the fire zone, the most important point of all Assistant Engineer. Gas Producer Department, WellmanSeaver-Morgan Co., Cleveland, Ohio. in the operation of a gas producer. If the ash zone is allowed to exceed a reasonable limit, say 15 in., the fire zone is considerably reduced, and it is impossible to carry the proper depth of fire if the ashes are not kept within a reasonable limit. This tendency of the ashes to crowd out the fire zone makes it possible for the top of the fuel to be at the proper height and yet the fire may be so thin that the gas will be of exceedingly poor quality. The only way the fires can be measured properly is to force the rod completely through the fire and allow it to remain long enough to become red hot. After the rod has been withdrawn, it is easy to see the part which has been in contact with the hottest portion of the fire and the part which has been protected by the ashes. Knowing the distance to the blower or the metal parts of the producer, it is a simple matter to tell exactly the depth of the various zones. A very convenient rod for this work is shown in IDEAL CROSS SECTION OF PRODUCER the view and consists of a 1-in. gas pipe marked into 2-ft. sections by 1-in. rivets running through the pipe. Any other method of marking may be used which will not be destroyed by the action of the fire or interfere with the passage of the pipe through the fuel bed. A mark is also placed at the height equal to the distance between the blower and the producer top. This indicates the distance the rod should be forced into the producer. In using the rod, the distance to the top of the fuel bed is first determined. (See Fig. 1.) The rod is forced through the fuel bed until the lower end is on a level with the top of the blower and allowed to remain there for two or three minutes. This is usually all the time necessary for the rod to remain in the fire. being withdrawn, it will be noted that there are two parts which show up distinctly-one a smoky black extending for several feet, and the other a very hot portion usually from 12 to 14 in. in length. This latter On |