Wheat Drying Research Articles

A study of the application of the spouted bed technique to wheat drying

AbstractA description has been given of a method which can be used to agitate solids that are of too coarse and uniform a particle size to be fluidized satisfactorily. This method has been applied to the drying of wheat. The following variables have been studied on a small pilot‐plant scale: feed moisture content, feed rate, bed depth and inlet air temperature. A description has been given of the temperature and humidity profiles within a wheat bed agitated by this technique.

A technique for contacting gases with coarse solid particles

AbstractAlthough coarse, uniformly sized particles are not amenable to fluidization, it has been found possible by use of either gases or liquids to impart a regular cycling motion to a bed of this type of material in which the solids are rapidly carried upward by the fluid in a central well‐defined core within the bed. The particles move uniformly downward in the annular space surrounding the core, thus providing dense‐phase countercurrent contact between the fluid and the solids. There is no wall separating the core from the annulus. This method is called the spouted‐bed technique. The effect of column diameter, fluid inlet diameter, bed depth, and physical properties of solids and fluids on spouting behavior has been investigated. The minimum fluid velocity required for spouting has been correlated, and the flow pattern of the fluid and of the solids has been stuided. The technique has been applied to the drying of wheat.

Evaporation in low vacuum from warm granular material (wheat) during the falling-rate period

The effect of various factors on rate of drying of wheat (below the critical moisture content) has been studied at temperatures in the range 12°-45° c., and under absolute pressures in the range 0.5–8 cm. of mercury. The results imply that the rate of diffusion of moisture within individual grains remains the factor governing rate of drying in vacuo in the manner known for air-drying in the falling-rate period, and that the rate of change of the diffusion coefficient with temperature (over the range 12° 46° c.) is the same as that of the vapour pressure of water. Within the range 13–30% moisture content (dry-weight basis), the rate of drying in vacuo is directly proportional to the free water content, but the term ‘free’ means the difference, not between total and equilibrium moisture contents as in air-drying, but between total and firmly held or bound water, the level of which must depend upon temperature: at 30°-40° c. it is about 9–10% (dry-weight basis). However, with wheats of similar total moisture content, the rate of drying is greater if the concentration of moisture in the outer layers is higher than that in the interior of individual grains, as in freshly wetted wheat. Variation in pressure affects directly only the rate of removal of vapour which has already left the solid, but this in turn affects the rate of drying. The effect depends on impedance to vapour movement caused by form of apparatus and disposition of the material, and can be substantially counteracted by admission of a small sweeping current of air, the optimum proportion of which is equimolecular with respect to the evaporated water.

Evaporation in low vacuum from warm granular material (wheat) during the falling‐rate period

AbstractThe effect of various factors on rate of drying of wheat (below the critical moisture content) has been studied at temperatures in the range 12°‐45° c., and under absolute pressures in the range 0.5–8 cm. of mercury. The results imply that the rate of diffusion of moisture within individual grains remains the factor governing rate of drying in vacuo in the manner known for air‐drying in the falling‐rate period, and that the rate of change of the diffusion coefficient with temperature (over the range 12° 46° c.) is the same as that of the vapour pressure of water. Within the range 13–30% moisture content (dry‐weight basis), the rate of drying in vacuo is directly proportional to the free water content, but the term ‘free’ means the difference, not between total and equilibrium moisture contents as in air‐drying, but between total and firmly held or bound water, the level of which must depend upon temperature: at 30°‐40° c. it is about 9–10% (dry‐weight basis). However, with wheats of similar total moisture content, the rate of drying is greater if the concentration of moisture in the outer layers is higher than that in the interior of individual grains, as in freshly wetted wheat. Variation in pressure affects directly only the rate of removal of vapour which has already left the solid, but this in turn affects the rate of drying. The effect depends on impedance to vapour movement caused by form of apparatus and disposition of the material, and can be substantially counteracted by admission of a small sweeping current of air, the optimum proportion of which is equimolecular with respect to the evaporated water.

The drying of wheat. IV. Phosphatase activity as an index of heat damage in cereals

AbstractThe baking quality, germination vitality and phosphatase activity of a wheat were examined after heat treatment at moisture contents ranging from 5.5 to 35%. Curves relating the percentage of phosphatase inactivation to temperature of treatment are presented. The correlation between phosphatase inactivation and damage to either vitality or baking quality varies with moisture content and is less than that between vitality and baking quality in the important region above 15% moisture. The detection and uset of an ezyme system of greater heat lability than phosphatase is desirable for the unequivocal diagnosis of mild damage to either vitality or baking quality of wheat.

The drying of wheat. Part I. The further drying of manitoba wheat

Journal of the Society of Chemical IndustryVolume 62, Issue 7 p. 93-97 Article The drying of wheat. Part I. The further drying of manitoba wheat H. D. Mounfielc, H. D. Mounfielc Research Association for British Flour MillersSearch for more papers by this author H. D. Mounfielc, H. D. Mounfielc Research Association for British Flour MillersSearch for more papers by this author First published: July 1943 https://doi.org/10.1002/jctb.5000620701Citations: 5AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Citing Literature Volume62, Issue7July 1943Pages 93-97 RelatedInformation

The Processing Taxes and Some Problems Raised by Them

Agricultural commodities on their way to consumption are usually subjected to one or more processing operations in order to prepare them for use. Individual definitions of processing are given in the agricultural adjustment act for six of the fourteen commodities designated by it as basic. Thus, the processing of wheat, rice and corn means the milling or other processing (except cleaning and drying) of wheat, rice, or corn for market, including custom milling for toll as well as commercial milling, but not include the grinding or cracking thereof not in the form of flour for feed purposes only. The processing of cotton means the spinning, manufacturing, or other processing (except ginning) of cotton; and the term 'cotton' does not include cotton linters.