Miller Magazine Issue: 150 June 2022

74 COVER STORY MILLER / JUNE 2022 Grain Cleaner is a very important equipment to clean the grain before storage (Pre-Cleaner) and before mill- ing (Fine-Cleaner). When we pass the grains through Pre-Cleaner before transferring the grains to Storage Si- los it helps in achieving the following benefits: • Aeration costs reduce as grain dust and impurities tend to generate high-density areas which generate re- sistance to aeration flow. • Reduces in-storage shrink loss of grains and grain damage also decreases due to infestation. Grain dust is highly susceptible to get infested. • Storage at higher moisture content possible due to lesser dust particles which develops into mould growth and foul smell in high moisture grains. • Cleaning Reduces transportation costs. • Cleaning grains makes the density inside the silo uni- form which improves the effectiveness of fumigation. • Reduce the requirement to turn-over the grains. Flat bottom silos have a flat concrete base having a row of discharge openings along its diameter to reclaim grain from the silo. The grain from these discharge open- ings is received by grain unloading conveyors that are installed just below these discharge openings in a tunnel. A tunnel is an integral part of all flat bottom silos foun- dations. These tunnels are designed to house unloading gates & unloading conveyors. Besides, tunnels provide access to operate, maintain, and clean this equipment in safe manner. Pre-Storage is a set of single or multiple silos which is located in between grain receiving pits and cleaning section of a grain storage facility. Pre-Storage silos bring efficiency to the storage system and make the operation trouble-free. The Rrequirement of the pre-storage silo is to create a buffer between receiving pit and the clean- ing section. This buffer ensures that conveying system, as well as the cleaning section, can get continuous and uniform feed. Conveyors, elevators, cleaners and rotary sieves etc. perform at their highest efficiency when the feed is continuous and uniform. Besides, uniform and continuous feed saves us a lot of electric power too. Preventing dust explosions, the grains have an inher- ent characteristic to generate dust whenever it is con- veyed or transported from one point to another, and this grain dust is highly combustible in nature. It is even more combustible than coal dust. As per available data, dust explosions can occur where any grain dust cloud is available in high-enough concentrations in the atmo- sphere i.e., within lowest concentration limits of 0.050- 0.100 kg/m3 and highest concentration limits of 2.0-3.0 kg/m3. Once this concentration condition is met with grain dust cloud can ignite at a temperature as low as 300 C. Grain storage occupies a vital place in the organiza- tions (whether it is small or big) of developed and devel- oping countries. Well, the truth is that silos are the best solution for preserving grain quality for a longer period.