Vacuum Mixer/Cooler Improves Sand Quality with Lower Capital Investment.The Eirich Evactherm vacuum mixer/cooler is designed to cool and prepare green sand in one operation. Within the system, ingredients are pre-batched into weight scales and after a short period of dry mixing, the sensor measures moisture content and sand temperature. These measurements are used in conjunction with feedback from the compactibility data supplied by the sand tester to determine exactly how much water must be added for sand cooling and to maintain target compactibility. The water addition is metered in stages in accordance with a control algorithm. It accounts for initial sand temperature, moisture, compactibility and other programmable factors to optimize performance for each individual foundry. Sand cooling is achieved by reducing the boiling point boiling point, temperature at which a substance changes its state from liquid to gas. A stricter definition of boiling point is the temperature at which the liquid and vapor (gas) phases of a substance can exist in equilibrium. of water to the desired sand temperature. The portion of water added to cool each batch of return sand is boiled off. The saturated steam steam at the temperature of the boiling point which corresponds to its pressure; - sometimes also applied to wet steam. See also: Steam generated inside the mixer/cooler during this process is brought into intimate contact with all the sand and clay particles via the mixer. The mixer/coolers are available for throughputs from 30-l50 tons/hr for prepared green sand, yielding a light (53-lb/cu ft bulk density), strong (up to 35-psi green compression strength) and flowable prepared sand. Depending on the return sand temperature and required green compression strength, a dump-to-dump cycle in the largest mixer typically takes as little as 150 sec (24 batches/hr). The technology eliminates the need for a separate sand cooler, as well as its associated bucket elevator A bucket elevator, also called a grain leg, is a mechanism for hauling flowable bulk materials (most often grain or fertilizer) vertically. Early bucket elevators used a flat chain with small, steel buckets attached every few inches. , surge bin and belt conveyors, lowering capital costs. The system also does not require the air supply needed by conventional evaporative coolers. The resulting hot, moist air to the dust collection system is eliminated, and the need for your return sand dust collection system is halved. Overall, the mixer/cooler improves sand quality and provides increased shear strength For the shear strength of soil, see . Shear strength in engineering is a term used to describe the strength of a material or component against the type of yield or structural failure where the material or component fails in shear. , wet tensile strength tensile strength Ratio of the maximum load a material can support without fracture when being stretched to the original area of a cross section of the material. When stresses less than the tensile strength are removed, a material completely or partially returns to its and flowability, better gas permeability, lower water content at the same compactibility, and reduced friability fri·a·ble adj. Readily crumbled; brittle: friable asbestos insulation. [Latin fri of molding sand. The system consists of the company's R-Type mixer that has a rotating mixing pan and two high-intensity, counter-rotating mixing tools inside a vacuum-rated shell; component weight scales; a vacuum system vacuum system Urology A mechanical system used to facilitate and maintain an erection; an erection erector. Cf Penile implant. ; motor control center; and moisture, temperature and compactibility controls. |
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