i TEXAS AGRICULTURAL EXPERIMENT STATION R. D. LEWIS. Director, College Station, Texas Bulletin 7/0 r. 9.5 q‘ I ' ‘we i Drying and its Eiiects on the Miiiing Characteristics oi gouty/sum Qaain SECTION 1. ARTIFICIAL DRYING SECTION 2. WET MILLING in cooperation with UNITED STATES DEPARTMENT OF AGRICULTURE __ The TEXAS AGRICULTURAL AND MECHANICAL COLLEGE SYSTE I GIBB GIL CHRIST. Chancellor [Blank Page in Original Bulletin] 17 Preface The demand for more food and feed during the war years, and the development of varieties suitable for combine harvesting have caused a big increase in the Texas sorghum grain acreage since 1940. This increase has been greatest in South Texas where the humidity of the atmosphere is high. When the grain is mature enough for combine harvesting, it usually contains too much moisture to be stored safely in bags or bulk. The need for more information on artificial drying and the milling characteristics of artificially-dried sorghum grain was intensified when the Corn Products Refining Company decided to erect a large plant at Corpus Christi. This plant will process about 6 million bushels of sorghum grain annually. In 1947, the Midwest Research Institute, Kansas City, Mis- souri, was engaged by this company to organize a series of experiments to obtain specific information on these problems. Section 1 of this bulletin gives results of drying experiments conducted jointly by the Midwest Research Institute and the Texas Agricultural Experiment Station. Section 2 gives the results of studies conducted at the Northern Regional Research Laboratory, Peoria, Illinois, on the wet milling of the artificially- dried grain. A batch type farm drier, designed and tested by agricultural engineers of the Texas Station, was used in the experiments reported in Section 1. The fastest rate of drying and the lowest costs for power and fuel were obtained when the velocity of the air through the grain column was 80 to 90 feet per minute. The air temperatures found to be the most elficient for drying the grain to 12 per cent moisture were 150°F. for grain with 14 to 16 percent moisture; 17 5°F. for grain with a moisture range of 17 to 20 percent; and 200°F. for grain above 20 percent moisture. The costs per ton for electric power and natural gas fuel were approximately 20 cents for grain with 14 to 16 percent moisture; 25 cents for 17 to 20 percent moisture grain; and 40 cents for grain with 21 to 24 percent moisture. _Mart_in, with a moisture content up to 20 percent, was dried with air temperatures as high as 175°F. without detrimental effect on germination. The wet-milling characteristics of Martin and Early Hegari were not impaired by artificial drying to 11 to 13 percent mois- ture content with air temperatures of 125° to 200°F. C O N T_ E N T S Page Preface . . . . . . . . . . . . . . . . . . . . . . . . _ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 3 SECTION 1. ARTIFICIAL DRYING Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 5 Review 0f Literature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 6 Equipment Used . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Plan and Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .‘_. . . 14 General Plan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . 14 Collection of Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . i. . . . . . . . . 14 Air conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 15 Fuel and power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 18 Air temperature in grain column . . . . . . . . . . . . . . . . . . . . . . . . . .. 18 Moisture determinations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 18 Air measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 18 Static pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 18 Weight of grain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 18 Discussion of Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 22 The Drying Cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 22 Rate of Drying . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 22 Low-moisture grain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 23 Medium-moisture grain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 23 High-moisture grain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . y . . . . . . . . . 24 Stage-drying . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 25 Air Volume . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 25 Cost of Dperation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 25 Germination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 28 Summary and Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 33 Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 35 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 Experimental Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 43 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 43 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 44 BULLETIN 710 JUNE 1949 Drying and its Eiiects on the Milling Characteristics oi SECTION 1. ARTIFICIAL DRYING J. W. Sorenson, Jr., H. P. Smith, J . P. Hollingsworth and P. T. Montfort Department of Agricultural Engineering, Texas Agricultural Experiment Station, College Station, Texas F. E. Horan, Formerly Research Associate, Midwest Research Institute, Kansas City, Missouri SECTION 2. WET MILLING R. A. Anderson and R. L. Zipf, Northern Regional Research Laboratory, Peoria, Illinois Bureau of Agricultural and Industrial Chemistry, U. S. Department of Agriculture Section 1. Artificial Drying ORGHUM grain was grown in all but 25 of the 254 Texas coun- S ties in 1948. In this year Texas produced over half the nation’s crop. The importance of grain sorghums has grown steadily during the past 8 to 10 years. The acreage has increased from an average of 2,466,000 for the 10-year period, 1934-43, to 4,635,000 acres in 1948.‘ The increased acreage was stimulated largely by the war in an efiort to meet the great demand for more food and feed. The rapid growth of the industry was made possible, however, by the development of varieties suitable for combine harvesting. Thus, during the war, when labor was scarce, farmers were able to produce much more sorghum than could have been pro- duced had it been necessary to use more hand labor. As a result, combine type varieties represent over 80 percent of the sorghum grain grown in the State. The combine is now a common sight in the grain fields during the harvest season and is capable of harvesting as much as 100,000 pounds of grain a day. 1Crop Reporting Board, August 1, 1949. U. S. Bureau of Agricultural Economics. 6 BULLETIN 710, TEXAS AGRICULTURAL EXPERIMENT STATION The advent of combine harvesting has created a serious problem in some sections of the State. When the grain is at the proper stage for harvest, it usually contains too much moisture to be stored on the farm or to be transported to distant markets without the hazard of spoilage from heating. 11' the crop 1s left in the field until dry enough to permit immediate storage or shipment, heavy losses are likely to occur from storm and insect damage. In some instances, the crop does not mature evenly; the immature grain contains excessive moisture which prevents bulking the grain without risking loss from spoilage. This means that the crop must be dried because without natural or artificial drying it is highly perishable. Excess moisture in the grain is a primary obstacle to safe storage or shipment in all sections of the State. Even in the High Plains area, sorghum harvested in the fall has usually too much moisture to be stored directly as combined. The greatest need for drying facilities at the present time, however, is in the Gulf Coast section where the humidity is so high during harvest periodsthat it is difficult to store grains Without some method of artificial drying. Although the need for artificial grain driers is definitely established, very little information is available that can be used as a basis for design and selection of equipment. Realizing the need for research of this nature, a series of tests were conducted at Corpus Christi in June and July 1947 to obtain basic engineering data that would enable farmers to dry their grain on the farm more efficiently. The purpose of this section is to present the results of the drying experiments. The objectives were to determine: (1) the effect of air temperature and volume of air passed through the grain on the rate of drying; (2) the effect of air temperature and volume of air on the cost of fuel and power for difierent moisture ranges; and (3) the effect of artificial drying on the germination of the seed. REVIEW OF LITERATURE Some previous work hasbeen done by the Department of Agri- cultural Engineering on the artificial drying of sorghum grain. The information obtained in these studies showed that this crop can be dried by forcing heated air through it. The effects of various air temperatures and other factors, however, were not determined. Details for building and operating a farm ‘grain drier were given in Progress Report 9682 published in 1945. Experiments in the drying of sorghum grain, as reported in ZMcCune, W. E., H. P. Smith, P. T. Montfort and E. S. Holmes. Building and Operating a Farm Grain Drier. Texas Agricultural Experiment Station Progress Report 968, 1945. DRYING AND ITS EFFECTS ON SORGHUM GRAIN 7 Progress Report 953,3 revealed that milo could be dried in a bin type drier from 19.7 to 13.4 percent moisture content at a cost of approximately 56 cents per ton for fuel and power. Hegari was dried from a moisture content of 19.7 to 12.5 percent at a fuel and power cost of 52 cents per ton. In a column type drier, milo was reduced from an initial moisture content of 19.08 percent to a final moisture content of 11.39 percent at an operating cost of 41 cents per ton. Hegari was dried in the same drier from 19.25 to 11.78 percent moisture at a cost of 31 cents per ton. A test to determine the possibility of drying grain with un- heated air was made near Corpus Christi in 1945 by McCune, et alF. The drier was loaded with grain having an average moisture content of 16.41 percent. Air was blown through the grain for 8 hours. At the end of 4% hours, the moisture content had dropped to 15.01 percent. No further drop in moisture was obtained in the additional 3% hours of blowing. It was necessary to complete the drying with heated air. Tests were made by Hukill4 to determine the factors affecting the drying of corn and grain sorghum. He found that increas- ing the air‘ temperature resulted in a shorter drying time. He also found that when artificial heat was used, drying was gen- erally more economical at high temperatures than at low ones. Tests in the drying of sorghum grain by Fentons show the importance of vapor pressures in grain drying. He found that the temperature of the grain Was of greatest importance in affecting vapor pressure. As the temperature of the grain in- creased, the vapor pressure of the moisture held within the grain increased rapidly. The temperature of the grain was found to be the greatest single factor in drying. EQUIPMENT USED The drier used in the tests reported in this publication was an all-steel batch type drier patterned after the farm grain drier designed and tested by the Department of Agricultural En- gineering, Texas Agricultural Experiment Station. This drier is shown in Figures 1 and 2. A description of the first model of the drier was given in Progress Report 968. A description of an improved model (the one used in these tests) was given in Progress Report 1070, “Hay and Grain Drying—1946.” The drier is similar in principle to commercial grain driers 3McCune, W. E., H. P. Smith, P. T. Montfort and E. S. Holmes. Artificial Drying of Grain Sorghum, Texas Agricultural Experiment Station. Progress Report 953, 1945. 4Hukill, W. V. Basic Principles in Drying Corn and Grain Sorghum. Agricultural Engineering, Vol. 28, No. 8. pp. 335-338. August, 1947. 5Fenton, F. C. Storage of Grain Sorghums. Agricultural Engineering, Vol. 22, No. 5. pp. 185-188. May, 1941. 8 ‘ BULLETIN 710, TEXAS AGRICULTURAL EXPERIMENT STATION Figure 1. Typical farm drier de-signed by agricultural engineers of the Texas Agricultural Experiment Station. in that air is forced through thin layers of grain to reduce it to the desired moisture content. This is accomplished by using heated air as a medium to evaporate and carry away the ex- cess moisture. The moisture laden air must be replaced by less humid air if the operation is to continue. The amount of moisture present in the drying air and the velocity of the air through the grain will, therefore, determine to a large extent the rate of drying. a The drying unit consists of two vertical columns of grain separated by an air-tight chamber 4 feet wide, 6 feet high and 9 feet long. Each column is 6 feet high, 9 feet long and 10 inches thick. The walls of the two columns containing the grain are supported by 2 x2-inch angle irons spaced approximately 18 inches on centers. The walls are made of 16-mesh galvanized screen wire reinforced with diamond mesh metal lath. Heated air is forced into the central air-tight chamber and through the columns of grain. a The drier has a loading bin above the drying columns, and an DRYING AND ITS EFFECTS ON SORGHUM GRAIN 9 unloading bin below the columns. Each bin has a grain storage capacity equivalent to the total capacity of the two drying columns. Sliding gates are provided at the top and bottom of each column. The grain can be transferred quickly from the load- ing bin to the drying columns and from the columns to the un- loading bins with these gates. Since the drier is operated on the batch principle, the loading bin can be filled with high moisture grain while a charge is being dried in the columns. When the grain in the columns is dried, the sliding gates at the bottom of the columns are opened and the grain flows rapidly into the unloading bin below. The sliding gates are then closed and the gates at the top are opened so that the grain from the loading bin flows into the columns. The dry grain in the unloading bin is then removed and the loading bin refilled while the fresh charge in the columns is being dried. The capacity of the drier is approximately 6,000 pounds of 20 percent moisture grain sorghum. However, only half of the Figure 2. General view of drier and equipment used for the tests at Corpus Christi. BULLETIN 710, TEXAS AGRICULTURAL EXPERIMENT STATION Figure 3. Heating equipment, controls, gas and ’ electric meters used in the tests. Figure 4. A typical heating installation showing burner, safety controls and dial thermometer for determining tempera- ture of intake air. n 5T DRYING AND ITS EFFECTS ON SORGHUM GRAIN 11 drier was used for these tests. The average weight of each batch tested, therefore, was approximately 3,000 pounds. The loading hopper on the drier was filled by gravity from the storage bins made available for these tests. A loading spout was constructed for this purpose, as shown in Figure 2. The drier is equipped with a screw conveyor and portable drag-type elevator to convey the grain from the unloading bin on the drier to containers or to storage bins. A centrifugal, single inlet, single width blower with forward curve blades and 24%-inch wheel diameter was used toforce heated air through the columns of grain. The fan was operated by a 5 horsepower, single phase motor. A é~ horsepower, single phase motor was used to operate the screw conveyor and another the portable elevator. The air going into the drier was heated by an injector type industrial burner with a rated capacity of 500,000 b.t.u’s per hour based on 0.1 inch draft through the burner. Natural gas was used as fuel. The burner was installed so that the flame was directly in the air intake to the fan. The fan intake was extended, however, to prevent the flame from coming in direct contact with the fan bearings. This was done by a sheet metal tube the same diameter as the fan intake and 6 feet long. The heating equipment is shown in Figure 3. Automatic controls were installed to eliminate possible fire hazards caused by fan stoppage or flame failure. A typical- installation is shown in Figure 4. Recording instruments were used to obtain continuous records of the temperature and the relative humidity of the air entering the drier and the moisture laden air as it left the drier. In- struments used are shown in Figures 5 and 6. A single range portable potentiometer was used to obtain the temperature of the air in the center of the grain column. This equipment is shown in Figure 7. An anemometer suitable for air speeds of 75 to 2,000 feet per minute was used for taking air measurements. Static pressure readings were made with a vertical manometer. A Steinlite moisture tester was used for all moisture determi- nations. A standard grain probe was used to obtain representa- tive samples, as shown in Figure 8. 12 BULLETIN 710, TEXAS AGRICULTURAL EXPERIMENT STATION Figure 5. Recording thermometer for obtaining a record of the temperature of the air in the plenum chamber. Figure 6. Recorder for obtaining a continuous record of the wet and dry bulb temperatures of the air leaving the grain. _@>._»_‘_ mill- 5T DRYING AND ITS EFFECTS ON SORGHUM GRAIN 13 Figure 7. A potentiometer with switch for obtaining the temperature of the air in the center of the grain column. The recording thermometer is shown at the right. A grain probe being used to obtain a sample from the center of the grain column. Several samples were taken for each test during the drying operation for moisture determinations. "l4 BULLETIN 710, TEXAS AGRICULTURAL EXPERIMENT STATION PLAN AND PROCEDURE General Plan Twenty-seven batches of Martin‘ and 10 batches of Early Hegari were used in these tests. Both varieties were harvested on the W. T. Bernsen farms near Violet. The grain was harvested with three difierent moisture ranges, depending on the conditions at the time of harvest. For the pur- pose of these tests, the moisture ranges were classified as low (14 to 16 percent), medium (17 to 20 percent) and high (2‘1 to 26 percent). Each batch was hauled to the Eastern Seed Company ware- house in Corpus Christi, where it was Weighed and a composite sample taken for moisture determinations and germination tests. The grain was then cleaned with a Clipper cleaner to remove as much trash, sticks and green weed seeds as possible before loading into the drier. The drier column was then filled with approximately 3,000 pounds of clean grain for each test. Thirty-four of the batches were dried with four different air temperatures, 125°, 150°, 175° and 200° F. Another batch was dried with an air temperature of 230° F., and the remain- ing two at two different air temperatures. One batch was dried with an air temperature of 150° F. during the first half of the operation; this was increased to 230° F. during the second half. These treatments were reversed for the other batch. Some of the grain in each variety was dried to a moisture content of 11 to 13 percent, while the other was dried to a moisture content of 7 to 9 percent. The operating schedule used is given in Table 1. After each batch was dried, it was unloaded from the drier into 50-gallon drums and sacks, as shown in Figure 9-. Part of the grain was then shipped to the Northern Regional Research Laboratory, Peoria, Illinois, where tests were made to determine the effect of artificial drying on the wet-milling characteristics of the grain. The remainder was stored in the Eastern Seed Company warehouse. Collection of Data The following information was obtained during the drying operation for each test: Temperature and relative humidity of the entering air. Air temperature in the plenum chamber. Wet and dry bulb temperatures of the air leaving the grain. Fuel and power used.’ A Time required to dry the grain to the desired moisture content. _ ,_V,,;' - Temperature of the air in the center of the grain column. j‘- DRYING AND ITS EFFECTS ON SORGHUM GRAIN 15 Moisture content of the grain at the start, during the drying operation and at the end. Quantity of air forced through the grain column. Static pressure in the plenum chamber. Weight of the grain at the end of the drying period. Air conditions. Continuous records of the condition of the entering air, the air in the plenum chamber and the exit air were maintained for each test. A summary of the air conditions for individual tests is given in Table 2. ~ TABLE 1. OPERATING SCHEDULE l Moisture range, percent Drying air Batch Crop temperature no. At start At end degrees F 5 Early Hegari. . . 17-20 11-13 125 6 Early Hegari. . . 17-20 11-13 150 7 Early Hegari. . . 17-20 11-13 175 8 Early Hegari. . . 17-20 11-13 200 9 Early Hegari. . . 14-16 11-13 125 10 Early Hegari. . . 14-16 11-13 150 11 Early Hegari. . . 14-16 11-13 175 l2 Early Hegari. . . 14-16 11-13 200 18 Farly Hegari. . . 17-20 7-9 150 20 Early Hegari. . . 17-20 7-9 200 525 Martin . . . . . . . . . 21-26 '11—13 125 26 Martin . . . . . . . . . 21-26 11-13 150 27 Martin . . . . . . . . . 21-26 11-13 175 28 Martin . . . . . . . . . 21-26 11-13 200 29 Martin . . . . . . . . . 17-20 11-13 125 30 Martin . . . . . . . . . 17-20 11-13 150 31 Martin . . . . . . . . . 17-20 11-13 175 32 Martin . . . . . . . . . 17-20 11-13 200 33 Martin . . . . . . . . . 14-16 11-13 125 34 Martin . . . . . . . . . 14-16 11-13 150 35 Martin . . . . . . . . . 14-16 11-13 175 36 Martin . . . . . . . . . 14-16 11-13 200 37 Martin . . . . . . . . . 21-26 7-9 125 38 Martin . . . . . . . . . 21-26 7-9 150 39 Martin . . . . . . . . . 21-26 7-9 175 40 Martin . . . . . . . . . 21-26 7-9 200 41 Martin . . . . . . . . . 17-20 7-9 125 42 Martin . . . . . . . . . 17-20 7-9 150 43 Martin . . . . . . . . . 17-20 7-9 17 5 44 Martin . . . . . . . . . 17-20 7-9 200 45 Martin . . . . . . . . . 14-16 7-9 125 46 Martin . . . . . . . . . 14-16 7-9 150 47 Martin . . . . . . . . . 14-16 7-9 17 5 48 Martin . . . . . . . . . 14-16 7-9 200 50 Martin . . . . . . . . . 21-26 11-13 230 4 511 Martin . . . . . . . . . 17-20 11-13 150 and 230 522 Martin . . . . . . . . . 17-20 11-13 230 and 150 lBatch 51 was dried by using an air temperature of 150° F. for the first 30 minutes and then increasing the temperature to 230° F. for the last 30 minutes. . iBatch 52 was dried by starting with an air temperature of 230° F. and then decreasing the temperature to 150° F. during the last 30 minutes. 16 BULLETIN 710, TEXAS AGRICULTURAL EXPERIMENT STATION ¢.¢@ o.mm N.m@ ¢.~» ¢.mH~ ¢.¢@H m.HHH ¢.@w >.m cam w.¢@ m.mw ow m.>@ ¢.Hm m.Hw @.@w m.mHH ¢.>mH m.w¢H ¢.woH ¢.¢ com w.»w o.mw wm H.¢w ¢.N@ ~.¢@ ¢.Hw H.w@ o.oHH m.w@ o.H@ H.» Qwfi m.- w.mw ~H H.@m ¢.>m o.m@ ¢.N> m.NoH o.wHH o.ooH ¢.Nm ¢.@ m>H >.>m w.@w > m.~¢ ¢.¢N o.>m Q.m@ w.>~H o.NvH Q.mmH o.om ¢.@ mbfi w.¢m m.Hm vq m.~¢ ¢.mH ¢.~m o.w@ w.~m~ @.m¢H ¢.m~H ¢.N@ w.> m>~ ¢.~> w.ww mw m.ww m.m¢ m.@@ o.¢w w.@@ ¢.wHH ¢.@@ ¢.~w m.m ¢w~ @.@m w.¢m mm ¢.ow o.wm m.wm o.>@ v.@¢H ¢.Hm~ w.¢oH m.mm N.» mbfi m.ww @.@w Hm ~.§@ ¢.Hm H.@@ ¢.¢¢H H.oH~ m.¢mH ~.@¢H ¢.@w w.» m>H >.¢@ w.Nw mm o.wm o.mm ¢.¢w ¢.@m m.@¢H o.vmH m.~oH o.ww m.§ m>H ~.w» m.>w >N @.>¢ ¢.@N ¢.wm o.~m o.wHH ¢.¢mH ¢.>HH o.>w ~.oH omfi ¢.N@ m.¢@ wfi H.>w o.H¢ ¢.w¢ o.N@ ¢.ooH o.mHH ¢.@¢H o.mw @.¢H -mfi v.wm w.ww ofi @.@¢ m.@~ m.¢¢ m.w@ w.m¢~ ¢.~NH o.mHH @.¢m m.HH amfi m.m@ @.H@ w ¢.o¢ ¢.mN ¢.m~ o.ww ¢.@_H @.¢mH m.¢~H o.>w @.@ ¢mH w.@¢ H.m@ wv >.N¢ ¢.mN m.mN =.@w m.w~H o.NmH m.mNH o.ww w.NH Qmfi ¢.mw ~.Hm Nw N.=m o.om w.Hm ¢.¢w H.moH ¢.>H~ m.HoH ¢.¢@ m.HH omfi @.w@ @.@w wm w.w@ ¢.@m ¢.mm ¢.>> v.HoH ¢.@H~ m.m¢H ¢.>w m.HH amfi m.mm @.w@ om H.wm ¢.mm ¢.N@ ¢.~w ¢.>oH o.mm~ o.~HH ¢.@w w.~H omfi w.w@ H.@w mm @.ww ¢.~w ¢.>m ¢.w@ ~.¢ofi ¢.¢NH ¢.@¢H m.ww m.m~ omfi w.@w w.Hw mm m.~@ ¢.m¢ o.ow ¢.¢w m.w@ ¢.@¢H o.o¢H o.ww ¢.¢~ wwfi w.ww N.m@ m ~.Hm ¢.¢m ¢.m¢ m.~w H.~o~ o.-~ ¢.¢¢H o.ww m.NN mmfi w.>@ @.~m m w.¢@ o.wm m.wm ¢.mw N.>¢~ m.¢H~ @.m~H o.mw o.om mwfi >.m@ @.@w mq ¢.w¢ ¢.wm m.wm ¢.~w @.w¢H m.m- m.m~H ¢.m@ o.om mmfi >.>> @.>w Hv ...... ¢.~¢ o.wm ....... @.»@ o.~H~ ¢.HoH ¢.¢w ¢.¢N mmfi w.~w w.mw bm N.w¢ o.mm ~.@¢ @.m@ ¢.m¢H o.m~H @.¢¢~ m.N@ ¢.~N mwfi @.wm ¢.~m mm ¢.@m ¢.m¢ m.¢¢ ¢.~> ¢.m¢H m.o~H ¢.@oH ¢.@m Q.mN mmfi ¢.@@ H.¢m mm w.@@ ¢.w@ o.mw ¢.@w N.wm ¢.@¢H ¢.>@ ¢.Hm ¢.mN mmfl >.mw N.¢w mm d>< m w fi .w>< m m H $833 H fiww usmukmn um .w% . 4 S3285: .w.~suw$afiwp Spmzflsn 6hsfifiwafiwu 6a pcwfiwm zfiumfiss QZPQEM Hm .www flan ~AAQ wig? mww$>< mfiafiw» mw§o>< supwm @w-¢>4 @w-@>1 ZR 3mm 1R wswCQ was mxficH UZCwMQ wzsmE mZOFEQZOO ~24 MO WMmw~ b4» .52» wfinwpco £4“ ..wctfiw mcisw $393“ hpnzfiss mfififiwa vs.» onsawaomfiwp fix wwmmwsOfi H.@w o.om m.¢> o.mw ¢.>¢~ ¢.m~H ¢.>¢H o.om mo.~H|o.m ¢mH|om~ m.ow H.@w w.@@ ¢.m¢ m.@w ¢.>> @.¢¢H ¢.w~H o.oo~ o.mw +¢.~ |¢.oH ¢@~|omH m.@@ o.ww >.ow ¢.>¢ m.@@ ¢.~w N.¢Q~ o.~uH c.Ho~ o.wm ¢.m omu @.H@ m.om ».@m m.Hm @.¢@ o.ooH ¢.w- ¢.w¢H c.vHH ¢.H@ ¢.m cow w.~m H.@w ¢.w@ m.ov m.>w ¢.Nw w.~¢H ¢.@~H ¢.~@ o.mm ¢.¢ com m.»> m.mw o.ww ¢.¢¢ ¢.¢> o.m> ¢.moH ¢.w~H o.mm ¢.N@ w.” mom w.H@ m.om ¢.@@ m.N~ m.¢> o.ooH m.¢~H o.m¢~ @.m¢H o.mw @.m com >.Nw m.om ¢.>¢ o.HN ¢.m¢ o.mw @.¢NH ¢.@¢H w.¢~H ¢.¢@ N.v com ~.mw ¢.m@ ~.¢> ¢.Hw ¢.mw ¢.m> w.@@ m.@o~ m.~@ o.¢@ w.m oom w.mm w.~@ v.~@ ¢.~m w.w@ ¢.¢@ @.@¢H ¢.>~H ».woH m.ww ¢.¢ com w.mw w.mw 18 BULLETIN 710, TEXAS AGRICULTURAL EXPERIMENT STATION Fuel and power. Records were also kept of the number 0f cubic feet of gas consumed and the kilowatt-hours of electric power required for each test. The operating costs for fuel and power were determined from this information. Air temperature in grain column. Information concerning the temperature of the air in the center of the grain column was desired for three reasons: (1) to determine the difference between the temperature of the air in the plenum chamber and that in the grain column as the drying progressed; (2) to de- termine the effect of plenum air temperature, grain moisture content and air flow on the rate of temperature rise in the grain, and (3) to determine the maximum temperature reached in the grain column. To obtain this information, four thermocouples were placed in the center of the column equally spaced along the length and halfway between the top and bottom of the column. The average of these four readings was taken as the temperature in the center of the column at any particular time. These readings were taken at intervals during the drying period. Moisture determinations. In addition to a composite sample at the beginning of the test, samples were taken for moisture determinations during the drying operation and at the end. They were obtained from the center of the column of grain by means of a probe, as shown in Figure 8. Two samples were taken at the end of each test-one when the burner was turned off and the other after cooling. The first was taken with a probe while the other was a composite sample taken during the unloading operation. Part of the composite sample was used for the germi- nation tests. Air measurements. The velocity of the air moving through the grain column for each test is shown in Table 3. The measure- ments Were made at 24 different locations on the outside of the grain column and the average was taken as the air velocity in feet per minute. Figure 10 shows the method used to make these measurements. Static pressure. Static pressure measurements were made ‘through g-inch holes drilled in the end walls of the plenum ‘chamber. The average reading for each test is given in Table 3. Weight of grain. The grain was weighed as it was brought in from the field. In many cases, however, several batches were brought in one load so that the weight of each batch at the start could not be determined accurately. After the grain was cleaned, the weight of the trash and other material was deducted to ob- tain the Weight of the clean grain. Each batch was weighed after drying and this record kept for each test. This information is given in Table 3. g ww-rrw rvw-r-wnwwwng-wwwvwv-r-w-w-pwp-vqv-wm-r DRYING AND ITS EFFECTS ON SORGHUM GRAIN __ 19 s g. 5 i‘ Figure 9. Above. Unloading grain from drier into 50-gal1on drums and sacks. Figure 10. Right. Using an anemometer to measure the ve- locity of the air moving through the grain column. i‘ ’ 20 BULLETIN 710, TEXAS AGRICULTURAL EXPERIMENT STATION ¢w.w 8 44.4.44 84.444 $4.8 1.45.4. 48 84 . . . . . ..4444.82 N4. mw.w 8 3.3 2.3 4.4.4.8 4.44.8 om m3 ........444482 24 £4 31w 4.4.8 44.4.4.4 444.8 8 4.8 ........44$.82 4.4. 3.2 3.44 4.44.8 24.4 484.4 4.8 m2 .....:.4444.82 4444 3.2 mm ow.3 344w 95.2 .. .. ¢m4 ........444482 mm oww 8 8.3 wwmw m2w.w 448.8 m2 m3 .......44$.82 S m¢.w E. 3.3 45.2 542w .. cow ........4444.82 mm m2.w S. ww.2 3.2 344w 43 .. .....44$.82 mm ¢w.w 4% $4.2 3.2 wmww . . o3 .. .4444.82 44w mmw .8 @422 3.2 2.4.44 $3 3 44.54 m3 ...4444.4442 44.. 8.4 3.3 3.3 44.4.4 32.44 8 oow .4582 wm 8.4 3.2 5.2 84.4.8 244.4 8 m3 .. .4582 44 3.w 8 ww.2 mm.3 244.8 ommw w» 34 . .. 34444.82 8 3.w 24 3.3 5.3 39w 4.44.4 4.44 m3 .. . .4382 44 4mm 43.4w mmm.w 443m 4.2 oow ........4444.82 ww 3.2 3.2 4.8.8 4424.4 £48 84 m2 ........44B82 8 3.w m3 $22 44.8 45.4 4.3mm 4.44.8 84 .......44B.82 mw 4.4.4 3.3 2.4.4 23.4 34.4 8 m3 ........44$.82 mw 4.4.4 S 8.44 3.3 2.4.8 244.4 $4 84 24.833 44.2.4.3 8 £8 24 24.44 .444: 448.8 84am 24 4.4.4 ..44~4am .44: 44 -o-u-nu¢-- on .--u-n- ¢o-..-- ¢.¢-¢¢--¢ -¢.---¢- H 3.4 8 213 .43.: 444.4 $4 .4.8ww2.2 444m 3 8.8 84 4.4.44 4.4.4.4 444.4...” 48.4.84 44mm 84 ..4.s4am .444 m 4 8.4 8 3.2 2.3 4.8.8 48 m 84 mew 14.8842 b4 H 4 m2.w 44 wm.2 448.444 448.4 4.44.8 84 4.4.4 148M442 424 H 4. oww 44 $4.3 8.44 844.4 4.4.4..” 34 2.4 24.8842 28H 4. mw.w 4.3 $.22 @942 $4.8 844 w m2 mw 248M442 428M m 4444423 49444444444 v48 4.4448 M44242. 4.444.444. .44: .42 $24 .4883 4423444 .644 34 424 .4344 4443mm 4282.4 .3 644484244484 44940 .24 644443.444 434 . . . 24444644494 .48 . 488m 4444.434 .4432?» 444449844 4.4a: .4488 22.68444 M44342 488444444 .434 $444548» 494444.482 4o 444E845 445940.42 ZO~P<2MO-Z~ AA14q4qi“ . BULLETIN 710, TEXAS AGRICULTURAL EXPERIMENT STATION Hm.¢ ¢¢.¢ ~N.o mm.o m>.H mm.H mm.¢H ¢w.wH com mm mm.o @>.¢ @~.¢ ¢m.¢ wm.m wo.m ¢m.w ¢H.¢N com ow @¢.¢ @m.¢ m~.¢ wm.o wm.N w¢.N ¢@.> ¢H.¢~ cam wm mN.¢ om.o w~.o ~H.¢ mm.H m>.¢ w~.¢H mN.¢~ Qwfi HH w~.¢ ¢m.¢ wH.¢ @H.¢ >m.H ¢¢.H mw.oH wN.wH mbfl F Hm.¢ w¢.¢ ¢N.¢ -.¢ m¢.~ mm.H ¢m.@ >@.mH mbfi kw ~@.¢ ww.o mm.¢ mm.¢ mw.~ mm.m mH.m Nmhwfi mbfi mq @~.¢ mN.¢ ~H.o fifiuc mH.~ o>.o mm.HH N@.¢H Qwfi mm mm.o vmno wH.¢ w~.¢ w@.H w¢.H m@.~H Hm.>~ m@~ Hm @@.¢ ww.o wm.o Nm.o >m.¢ »w.m mH.@ ¢m.m~ mbfi mm mm.o mw.o mN.¢ ¢m.¢ @@.m mm.“ m>.~H mm.mm @>H pm »@.¢ >>.¢ @¢.¢ om.¢ wo.m wm.m @@.w m>.wH omfi wfi mm.o @m.¢ Hm.¢ ¢H.¢ Nm.~ >o.H ¢~.H~ ~@.¢H ¢mH ofi @N.¢ N¢.¢ mm.o >H.o >H.m >w.H w@.oH w~.wH cmfi w wm.¢ @@.¢ mm.¢ ¢N.¢ ¢¢.m om.m w>.m >w.mH omfi wv ow.o >w.o w¢.¢ mm.o w¢.¢ w@.m wm.@ Nm.wH Qmfi Nv >~.o ¢N.¢ mH.¢ @@.¢ mm.H ww.o wm.~H ~¢.¢H omfi Q” @N.¢ mm.o ~m.¢ NH.o mw.H ~m.H wm.HH mm.@H ¢mH om H>.o N@.¢ H@.¢ H¢.¢ m¢.m @¢.m ¢>.HH mH.¢~ Qmfi mm ¢¢.H vm.o ¢¢.¢ ¢@.¢ N~.m N>.¢ mw.@ mH.¢N omfi mm ¢~.¢ mm.o >N.¢ wo.o o@.H ¢m.H wv.~H o¢.¢H mmfi m >¢.¢ m@.¢ ¢¢.¢ @H.¢ mm.m Nm.N ~v.HH w¢.@H mwfi m ¢>.¢ ¢~.H ¢».¢ ¢¢.¢ m~.@ m>.@ wm.¢H >m.mH mmfi mv m~.H @m.H Hm.¢ w¢.¢ ¢m.~ co.» m¢.¢H Hw.wH mmfl Hv H>.H mw.H mH.H ¢».¢ o¢.m om.w >@.¢H wN.@~ mmfi vm mH.o @N.¢ H~.¢ wo.o »@.~ mm.H w>.~H mH.¢H mmfi mm H@.@ ow.o @¢.¢ Hm.¢ N@.m N¢.m ow.NH >@.wH mmfi mm HH.H w wH.H ww.o w w¢.¢ w mm.» ¢¢.> mw.HH @>.¢~ mmfi mm no» 8Q 62w Q 53x a; 5v cog 6.5 .3: wnw 3w 923m w< Q $3. nfimnfiwno 6s .323 wcw mum pwoo 3a om @ .82 vow © 2mm hméfism Hanoi E souum E5 uwoO 13cm. zfiowfiomso 3w . 388m mtsumfivmfio» “o pmoO we QwoO Q83 wfipfimaO sbwpcoo Espmmowm b4 wawou wzikmmmo é HAM3 2: $5 M92 N72 fiww fiw 3.2 3.: w»? sf $22 a? 34.5 .58 Qmnamw as amnsfi .55 Qmaofi Qa 8N 2N . . bpa 28 BULLETIN 710, TEXAS AGRICULTURAL EXPERIMENT STATION the true dry weights since some of the grain left in the loading hopper Was not dried to the moisture content shown for that in the grain column. It is believed, however, that the costs given are accurate enough for all practical purposes. In drying both Martin and Early Hegari in the low-moisture range to 12 percent, the cost of operation was practically the same for all air temperatures. When the grain was dried below 12 percent, however, the cost was much higher for an air tem- perature of 125° F. than it was for the higher air temperatures. Little variation in cost was shown in the 150° to 200° F. air temperature range. In drying medium-moisture Martin and Early Hegari to 12 percent, the cost for fuel and power with an air temperature of 125° F. was approximately twice the cost for fuel and power when an air temperature of 150° F. was used. The variation was very slight for 150°, 175° and 200° F. air temperatures. For the lower final ranges of moisture, however, the higher the air temperature used, the lower the operating costs. There seems to be a definite advantage in using the higher air temperatures for high-moisture grain as far as economy is concerned. For example, the cost for fuel and power in reducing Martin to 11 to 13 percent moisture was 46 cents per ton with an air temperature of 200° F., while the cost was $1.11 with an air temperature of 125° F. and 71 cents with 150° F. air temperature. This variation was not nearly as great between the 175° and 200° F. air temperatures. Germination Table 5 shows the results of the germination tests made on some of the dried Martin and Early Hegari. The air-dried samples were taken before the drying operations started; the other samples were taken at the end of the drying period. It is obvious from these tests that an air temperature of 200° F. has a detrimental effect on the germination of both Early Hegari and Martin. Although batches 37 and 38 show a low germination test for air temperatures of 125° and 150° F., respectively, it' is believed that this was due to the immaturity of the grain rather than to the air temperature. There is no way to estab- lish this fact since batches were not obtained for air-drying. On the other hand, it is entirely possible that there is a con- siderable reduction in the germination for high-moisture grain even with comparatively low air temperatures. It is interesting to note that there was a greater reduction in germination when the grain was dried in stages with 230° to 150° F. air tem- peratures than when 150° to 230° F. air temperatures were used. Evidently, there is a very detrimental effect on germination when a high heat is used at the beginning of the drying period. It appears that the germination is unusually low for batches 6. 7 and 8. It may be that, since Early Hegari is a soft grain, 150° to 200° F. air temperatures cause excessive reduction in IT DRYING AND ITS EFFECTS ON SORGHUM GRAIN 29 68.52%: cm p22 .5 comm 2s @3555 om 3E .5 .3: E fix mo waspmnomfiokfi dwpsfifi om 3.2 new QowH was mwpsfifi om 3.5 new oomw» .2830» 5.2m mo $9.22. mv . ow 2: .37.? .32 8.2 ............=s.a2 mm v m> .. . ow HwH amaéfi $2 3.2 .. .........:$.8H>H 8 aw . mm H>H com wmd 3.2 .. . . . . . .....c$.82 wv . >m . . mm >mH m>H vmd >92 ............s$.~w§ >v . mm . mm mmH omH w>.m >w.mH ........:B.EH>H wv H mm . . . 8 >HH mmH .32 5.2 .......sB.§§ mv mw . . . . mmH m>H mHd wmfwH .. . . . . . . ....EP:...§ mv ww ... .. wmH 3H wmd mmdH .. .........nE.5§ mv mw . .. wHH mmH mvdH Hw.wH .......QB.EH>H Hv vw .. .. mmH omH mwd mHvm ......,......c$._w§ wm om .. .. >HH mmH >w.oH wmavw .......n$.8§ >m E. .. mm mmH com >m.HH wmvH ............:£.8H>H mm aw mm mvH HwH NNHH wmvH .. ...EP:~H>H mm vm . .. .. mm mmH omH wmHH mvvH ............cHp.~wH>H vm H5 mm mHH mmH w>.HH mHvH .. . .......E».8§ mm aw . >vH m>H mmHH Hm.>H ............QHPEH>H Hm ww omH omH NNHH mmiwH ............aB.~mH>H am >m Hw m2 8N 3w 36H .......z~w¢m 5.8m 3 m ......> m v> >2 3H 2w m>.wH .......z~»@m 3.8m 2 m v> Q Q2 8N >H.¢H 2.3 ......€§Qm bafi NH . . . .. >> v 2. mvH s: £3 £3 .......€mw@m 38m HH v mm N vw vwH Q2 vH.HH N93 .......E.w@m 3.5m 2 mm v ow mHH mmH wvHH ¢v.vH .. . Iimwwm 3.8m m --¢ --- on . -¢- |¢--..?M“%@m w 1 . . . . . .-. ..-.-¢ .-......r.m@&@m § @ . . . . . . . - - - - . . - . . . - . - ¢ $ w - - - - - - - O .... -..--.r%fiw@m £ mpsoam .E.6U mpsoam .836 i»? v1.6.3 Fm a2. m $2. a8 ES i» t8. 3.. éhspwpwmfiw» mania mo Q30 6G mEEQm v2.6 @383 3.3m whspwpmafiwm. i1 sopmm mmimummfipv. wwtw-bv. Esctxwvm 262.3 ucwfion éoSmsHsEmU Jsmucoo ohspmmovm ZOHFHMHU 7H0 UZHFMQ Ar\ I‘ \ Z 4'0 UJ \ 9 T. O I U] O- |z \ \ _. \\ k ""““~7K I0 0 2O 4O G0 G0 I00 I20 I40 I60 TIME IN MINUTES FIGURE I9 MOISTURE CONTENT OF GRAIN DURING DRYING 3 i1 'MARTIN AND EARLY HEGARI G MEDIUM MOISTURE RANGE PERCENT MOISTURE-WET BASIS Z -a$_ _ _ 9 ‘*-_ ‘x r o 2o 4o so so I00 I20 I40 I60 Iao , ‘TIME IN MINUTES FIGURE 20 s: 11 MOISTURE convent or GIIAIN-f" m ouamo omrme r5 g MARTIN f, 1 men uoIsru-IE anus: '- 3 I ll-I g L25 _ \ ‘é I >_ ‘I250 F. 2 ~- 5 I \\ . Q 3 _ \ E N300 I \~ \ \\I---I I - P! 1 O 50 I50 ZOO Z50 300 550 400 450 TIME IN MINUTES FIGURE 2| DRYING AND ITS EFFECTS ON SORGHUM GRAIN 33 germination for this moisture range. Again, however. there is no check sample to show this point. It can be seen that for low- moisture-range Early Hegari, an air temperature of 200° F. is apparently the only one that has an appreciable effect on the germination. Although these tests are not sufiicient to draw definite conclusions, it appears that low and medium-moisture- range Martin can be dried with drying air temperatures as high as 175° F. without any detrimental effect on the germination. 'II‘Ihese tests also indicate that this is true for low moisture Early egarl. SUMMARY AND CONCLUSIONS A series of tests were conducted at Corpus Christi in 1947 to obtain basic data that could be used in designing and select- ing equipment for farm graindriers. The objectives were to determine: (1) the relationship be- tween the air temperature used and the volume of air passed through the grain on the rate of drying; (2) the effect of the air temperature and the volume of air on the cost of fuel and power, and (3) the effect of artificial drying on germination. The drier used for these tests was an all-steel batch type drier patterned after the farm grain drier designed by agricul- tural engineers of the Department of Agricultural Engineering, Texas Agricultural Experiment Station. Two varieties of sorghum grain were selected for the tests. Martin and Early Hegari were chosen because they are repre- sentative of over 9O percent of the grain sorghums now grown in the Gulf Coast area, where the need for artificial drying is the greatest at the present time. Each batch was cleaned with a Clipper cleaner to remove as much trash and green weed seeds as possible before loading into the drier. The drier was then filled with approximately 3,000 pounds of clean grain for each test. ‘ Thirty-seven batches ranging in moisture content from ap- proximately 15 to 26 percent were dried with air temperatures of 125°, 150°, 175°, 200° and 230° F. The results of the tests indicate the following conclusions: 1. The drying cycle for Early Hegari and Martin consists of at least two stages. The first stage is the evaporation of the surface moisture. The second stage is the difiusion of the moisture from the inside of the kernel to the surface where it is absorbed by the air moving through the grain column. The velocity of the air is an important consideration during the first stage as it governs the rate of drying. The drying rate during the second stage depends on the rate of diffusion. With the higher air temperatures, the rate of diffusion is high at first, but as the drying advances this process becomes slower 34 BULLETIN 710, TEXAS AGRICULTURAL EXPERIMENT STATION with the drying rate falling off rapidly near the end. The ulti- mate time of drying is, therefore, governed by the rate of both surface moisture removal and diffusion. 2. When an air temperature of 125° or 150° F. is used, the rate of drying during the second stage is comparatively slow. This is because a sharp break or change in the drying rate does not occur until Martin reaches 140° F. and the Early Hegari 130° F. The increased rate continues until the grain is reduced to a moisture content of about 10 percent. From this point to the end of the drying period, the rate of moisture removal de- creases rapidly. 3. The efficiency of the drying operation is very low after the grain has been reduced to a 10 to 11 percent moisture content. 4. The rate of drying Martin is greatly increased by using an air temperature of at least 150° F. This is also true for Early Hegari except when drying low moisture content grain (14 to 16 per cent) to 12 percent. In this case, with an air velocity of approximately 100 feet per minute, the drying rate is just as fast with 125° F. air as it is with higher air temperatures. 5. Early Hegari dries faster than Martin for all moisture ranges. This is probably due to the Early Hegari being a softer grain. 6. In drying Martin from a moisture content of 14 to 16 percent to approximately 12 percent, there is no advantage in using an air temperature above 150° F. when the velocity of the air leaving the grain is approximately 90 feet per minute. For the lower final moisture ranges, however, the higher air tem- peratures give faster drying rates. With a minimum velocity of 100 feet per minute, the rate of drying Early Hegari in this moisture range is just as fast with an air temperature of 125° F. as it is with the higher air temperatures. 7. When grain with 17 to 20 percent moisture is dried to 12 percent, the drying rate is just as fast with an air temperature of 175° F. as it is with a 200° F. air temperature, if the velocity of the exit air is a minimum of 80 feet per minute. The higher air temperatures, however, give the fastest rate of drying below 12 percent. 8. In drying grain with a moisture content above 20 percent, the higher air temperatures give a considerable reduction in the time required for drying when the velocity of the air through the grain column is a minimum of 80 feet per minute. 9. The two tests made by “stage drying” indicate that this method offers possibilities and may be found to give better results than maintaining a constant air temperature throughout the drying period. 10. Based on the air velocities used in these tests, the cost "('V"|v2!71v("vvy7wr“‘?" fiWn-wltjvw‘: DRYING AND ITS EFFECTS ON SORGHUM GRAIN 35 of fuel and power is practically the same for all air temperatures when low-moisture-range Martin and Early Hegari (14 to 16 percent) are dried to 12 percent moisture. Below this moisture level, the cost is much higher when an air temperature of 125° F. is used. There is little variation, however, in the 150° to 200° F. air temperature range. In drying medium-moisture grain (17 to 20 percent) to 12 percent, the cost is considerably higher when an air temperature of 125° F. is used; there is very little difference in the cost for the 150° to 200° F. air tem- perature range. The higher the air temperature, the greater the economy when the grain is dried below 12 percent moisture. In drying grain above 20 percent moisture content, high air temperatures are more economical than low ones regardless of the final moisture content. 11. These tests show that Martin with a moisture content up to 20 percent can be dried with air temperatures as high as 175° F. without any detrimental effect on germination. This seems to be true also for Early Hegari with a moisture content of 14 to 16 percent. The two batches dried in stages show a greater reduction in germination when the grain is dried with a high air temperature for the first half of the drying period and a lower air temperature during the last half than when this process is reversed. ACKNOWLEDGMENTS The authors wish to express their sincere appreciation and thanks to the following individuals who assisted in this work: H. L. Alsmyer, Nueces county agricultural agent, for his as- sistance in making arrangements for the grain used for the tests. W. T. Bernsen, farmer, Violet, Texas, for the very best co- operation in harvesting and delivering the grain to the drier. L. W. Clark, warehouse foreman, Eastern Seed Company, for his help in cleaning the grain before drying and providing stor- age for the dried grain. B. V. Hasselfield, State Department of Agriculture, for his valuable assistance in arranging for the germination tests. R. E. Karper, agronomist, in charge of sorghum investigations, Texas Agricultural Experiment Station, Lubbock, Texas, for his assistance in making arrangements for the drying tests and in the preparation of this report. H. O. Roberts, Jr., agricultural advisor, and W. E. McCune, agricultural engineer, both with the Central Power and Light Company, Corpus Christi, for their assistance in obtaining electric service. C. L. Shrewsbury, formerly chairman, Agricultural and Or- ganic Chemistry Research, Midwest Research Institute, Kansas City, Missouri, for making these tests possible, for his assistance in planning and organizing the tests and his help and advice in all phases of the work. 86 BULLETIN 710, TEXAS AGRICULTURAL EXPERIMENT STATION Section 2. Wet Milling of Artificially Dried Sorghum Grain In 1947 the Northern Regional Research Laboratory and the Corn Products Refining Company entered into a cooperative agreement which concerned the wet milling of samples of artificially dried sorghum grain. It was of vital interest to determine the conditions under which the grain could be dried without impairment of its Wet milling characteristics, especially with most of the grain likely to be harvested when its moisture content is comparatively high. As explained in Section 1, ar- tificial drying will be necessary under such conditions before the crop can be safely stored. Samples of the dried grain sent to the Northern Regional Research Laboratory for determining the effect of the drying conditions on the milling characteristics of the grain, were from the field drying experiments conducted by the Midwest Research Institute, Kansas City, Mo., and the Department of Agricultural Engineering, Texas Agricultural Experiment Station. In the drying tests, Early Hegari and Martin sorghums were harvested at three different moisture levels: high (21 to 26 percent), medium (17 to 2O percent) and low (14 to 16 percent). Batches at each moisture level were then dried with heated air at temperatures of 125°, 150°, 175°, and 200° F. Some samples were reduced to 11 to 13 percent moisture, while others were reduced to 7 to 9 percent moisture content. One batch of Martin was dried with air at a temperature of 230° F. Two batches of grain were dried in stages. That is, one batch was dried at 150° F. for the first 30 minutes, then the temperature of the air was increased to 230° F. the last 30 minutes. The other was dried at an air temperature of 230° F. for the first 30 minutes, then at an air temperature of 150° F. for another 30 minutes. Table 6 shows the composition of the various artificially dried samples just prior to milling. The grade of the samples “as received” i's given in Table 7. 37 DRYING AND ITS EFFECTS ON SORGHUM GRAIN N66 6.63. 66.6 63.3 N6.33 63.6 6m.mN .. . . . . . . . .......=333m2 6m 66N 6.63. 63.33 663 o3.N3 mw.6 63.6N . . . . . . . . . . . .....c33.82 wm m6.m 6.63. oN.o3 6N3 6N.N3 3.6.63 6N6N . . . . ........a33.82 3.m mN.m 3..63. mo.o3 663 3:8 omN N333 m6.o3 66.63 .. . . . . . . . . ..... 533.82 “N6 6N.m 6.63. oN.o3 omN 68 663 N6.33 N6.o3 66.3.3 ................a33.82 3.36 63..m 6.63. 66.6 6mN No.33 6m6 wN6N . . . . . . . . . .......:33.82 66 N6.m N.63. 66.6 ooN 66.33 63..o3 6m.63 . . . . . . . . . . . .....=33.82 6m N6.m N.63. 36.6 663 66.33 NN.33 N6.63 . . . . . . . . . . . .....c33.82 6m 6m.m 3.63. 6m.6 663 66.33 66.33 N6.63 I. . . . . . . . . . . ....z33.82 6m 66.m 6.3.3. 6m.6 6N3 NN.N3 63.33 63.63 . . . . . . . . . . . 224333.82 mm 63..m 6.63. 36.63 ooN 66.33 6m.o3 66.63 . . . . . . . . . 13.25382 Nm Nm.m 6.3.3. 36.6 63.3 m3..33 m6.33 36.3.3 . . . . . . . . . . . 1.2333382 3m 66.m 3.63. 63..6 663 N633 NN.33 6663 . . . . . . . . . . . . 1.433382 6m Nm.m 3.63. mm.63 6N3 N633 6m.N3 3.6.63 . . . . . . . . . . ......c33.82 6N 3.3..m 6 .33. m6.o3 ooN 66.33 66.3. 63 .6N . . . . . . . . . . . . . . ..c33.82 6N 3.66 3.63. 66.6 63.3 6N.33 m3..33 6m.mN . . . . . . . . . . . . ....z33.82 3.N w6.m 3.63. 66.63 663 66.33 63..33 63.6N . . . . . . . . . . . . . 14333.82 6N 66.m 3.63. 66.63 6N3 3 .N3 m6 .33 63..6N . . . . . . . . . . . . . . 2:33.82 6N 66.N 6 .63. 6N .6 66N NN.o3 6N6 m3..63 . . . . . . . . . ..3.8wm3m 63.8w 6N 66.N 3..63. 6N.6 663 63 .63 66.6 m3..63 . . . . . . . . . ..3.8mm3.3 63.8w m3 63..N 6 .63. mm.6 66N 66.63 3.3.63 No.63 . . . . . . . . . 1386mm 63.8w N3 66.N 6.63. 66.6 663 N6.o3 wN.o3 6N.63 .... . . . . . 1.3.8633 63.8w 33 m6 .N 6 .63. wm6 663 66.33 63.33 N6.63 . . . . . . . . . ..3§mmm 63.8w 63 m6.N N.63. 66.6 6N3 66.33 66.33 66.63 . . . . . . . . . 1386mm 63.8w 6 3.6.N 3.63. 666 66N 66.63 63.33 8.2 . . . . . . . ....3...mmm 63.8w m om.N 6.63. 3N.6 63.3 3.6.63 66.63 mN63 . . . . . . . ....3.8wm3.3 63.8w 3. 66.N 6.63. oN.6 663 No.33 66.63 mN.m3 . . . . . .... 13883.3 63.8w 6 63..N 6.63. 666 6N3 66.63 36. 33 66.63 . . . . . . . . 1.3.883 63.8w 6 3383mm 3893mm 383mm m. 383mm 3cmm8m 3383mm $8.8 m. zo .6265 35.23. 6m3wm>§3 33D 33m83m c3m3o3m 338 6236.36 863$ 3o 35w 85$ .63m33.m> .23 . . 3o m8 "@383 63w|co333momfioO m§38323EmH 3383383 m§3w3o2 A .m Z3<~3U 23338356 33.333363 23343033333536. m0 203636336200 .6 63133363. 38 BULLETIN 710, TEXAS AGRICULTURAL EXPERIMENT STATION dmpsfifi om mo.“ wm 0on2 3 wwwmwaow dwpscih om new RH comm op wwwwmnonm soap wismmpwmfiw» 2w $3555 om mow um in ¢ . .32“: a5 § rsfio Ewso .552 .5“ d >8 5w ..o.<.o.< 駧=< w. .11..i1li..z1.__ . w 22$ mpspwmwmfiwu fix mmwpscwfi om now wm comm 8 5w ..o.<.o.< aosswhpxm w=wxwm¢w=wpzwmimo HH .3“ USN 2.5mm JH Fm ~wo§w2 Qipwfiflmflomlsuampm mwofiwz .952: w_o=.fi<-wfi==su-_sww_wQlfifiogm "mwmfimsw we mwosuw2m .H0 QMSPQHQQEQQ Hwfi GM MN QQTMQH 06mm m0 QMSQNHQQQMQP is 2Q pd v2.2? uwczmfi 3 .692 $3. pcwpcoo w§5fio2N RMQTHU EOFM wwwwofiss 502T)? #500500 ofifimwo2fi w?“ w .3. 3.2 8N N32 3a $ .2 . . . . . . . . . . . . . . 15982 w“. Hm d o6» 3.2 m3 ow .3 3 d 5 .2 . . . . . . . . . . . . . . 150.82 5 3N v.5. 3.2 o2 2.: E. d 5 .2 . . . . . . . . . . . . . . ..n$.~w2 3 3N i; 20.2 2: $.22 £3 $42 ............%..5t~2 3 NH 4Q. o .5. 3 d 8N 32 mm w 3.2 . . . . . . . . . . . . . 123.82 $ 3...“ 2.? $0.2 EA 8.2 2d N93 . . . . . . . . . . . . . . ..c$.=w2 3 mm.“ 2.3. 3.2 o2 2.2 mm; N92 ..........m....dB.E2 fi S4“ 9E. 2.1m £4 £3 3.2 2.2 ............m...n$.§2 3 2d o .3. 3.2 8N mm . 2 3 w 2 6m . . . . . . . . . . . . .4532 3 pswupwm 230.6% “Ewohom P. 9663mm pcwukwm unwfiwm 6m .w x Z0 #558 flwfibw wmammaz; =0 £3.95 nmwpogm buwqrnhw awn? we vim QQSB b28> dc .6 , supwm Ewan zgwlnowmmoafionv PEQQEQSQH unwpsou mpsummo2 E==s==olz€mu 2DHUMOm QmiMQ >AA<~0P§HM< mo 2029592200 d H2249 “DRYING AND ITS EFFECTS ON SORGHUM GRAIN 39 TABLE 7. GRADES OF ARTIFICIALLY DRIED SORGHUM GRAIN Batch Grade‘ no. 5 No. 1 white kafir 6 No. 1 white kafir 7 No. 1 white kafir 8 N0. 1 white kafir 9 No. 1 white kafir 10 No. 1 white kafir 11 No. 1 white kafir 12 No. 1 white kafir 18 No. 1 white kafir 20 No. 1 white kafir 25 No. 1 yellow milo (trace of “toasted” odor) 26 No. 1 yellow milo (a very slight “toasted” odor) 27 No. 1 yellow milo 28 No. 1 yellow milo 29 N0. 1 yellow milo 30 No. 1 yellow milo 31 No. 1 yellow milo 32 No. 1 yellow milo 33 No. 1 yellow milo 34 No. 1 yellow milo 35 No. 1 yellow milo 36 No. 1 yellow milo 37 Sample grade yellow milo (“toasted” odor) otherwise No. 1 38 No 1 yellow milo 39 No. 1 yellow milo 40 No. 1 yellow milo 41 No. 1 yellow milo 42 No. 1 yellow milo 43 No. 1 yellow milo 44 No. 1 yellow milo 45 No. 1 yellow milo 46 No. 1 yellow milo 47 N0. 1 yellow milo 48 No. 1 yellow milo 50 Sample grade yellow milo (“toasted” odor) otherwise No. 1 51 No. 1 yellow milo 52 No. 1 yellow milo lGraded according to oflicial U. S. Grain Standards. 40 BULLETIN 710, TEXAS AGRICULTURAL EXPERIMENT STATION Z3 mmm mHm mmHm H3 5w» $5 3H .1. mHuwH 3. mdm 9mm mam 93m 9mm m5. Hm a 3H m1» $73 3 9mm m .mm m.mH m3“ mam Nam Hm... 8N ml» 2T2 3. m? H .mm m...» 22m 9mm m? HHfic 5H m|> omlLH m... 9mm mmm m8 mrmmm m am mm» 3... 3H ml. 8T5 N... mam mam HQH mmmm mmm HiHw 5... m2 @|§ 3&2 u. 9mm , mmm mQH 93a v.5 paw $6 8N ml. wmlHu 3 w? mmm 9E 13m mam mtmw £5 3H ma» wmuHm mm m.wm 5mm mQH H EN 92. H.mm mm... 3H m1» £13 mm m 5m wmm m.mH Hmwm :5 H.mm mmm mmH ml. mmlHm S 5mm w.wm m3 92a mmm Haw mm... 8N mH|HH wHlwH mm Hém m.wm H 9H 95m NS 5mm m»; mwH mHnHH $73 mm mam 9mm NQH 3.8 mam Nam m»... o2 mH|HH £13 Hm H.mm mmm H 5H mdbm 9mm 9mm mmm mmH mH|HH mH|H~H mm mdm mmm HfiwH mama ma” mmw m; 8N mHIHH mmabH mm 9mm H.mm mQH wmbw mmm 9mm mmm 3H mHaHH om|>H Hm Hém #8 m.mH Higm mmm 2% H»; 3H mHuHH 81S mm wmm H.mm mQH wtmmm m 3 9mm mmm m2 mHnHH 3A; mm 98 9mm m.wH 3mm HiHw 9% mm... o8 mHlHH mmlHw mm mam mmm HimH 98m 93 5mm 3d EH mHlHH mmlHm K 9mm mam EwH cs8 93 9mm £5 2H mHlHH mmFHm mm 95 m .8 m.wH wmHm m? m .8 mm... 3H mHIHH mm|HN mm QERZPHH pzwfiom EEBPHH mEEU mcwnfiwm QEWPSAH EQPSm w? pnwfiwm pamnzwm . .8“ .8.“ HEBPKH "EH63 cwfisw HEB» magnum Ea METHE. 33mins umpcsouuw wwuasooow E sobfim E mswfiv Mo mo HEW H855 d: HHmQuOmnH wwmow 5Q 8.6m mEQ EEPH E395 HEQQPFH Espmgwafiwk nopwm ZHBMH QHHMQ VAQ