Limestone and Clay

Pre-homogenizing Hall
Application: The raw materials required to manufacture cement are limestone and clay. Limestone rock extracted from the quarry is taken by truck to the nearby cement plant. The rock from the quarry is routed to a grinding plant where it undergoes initial crushing before being reduced to a fine powder. The raw materials (80% limestone and 20% clay) are then stored in the pre-homogenization pile. This mixture is called the raw mix.

Challenges: The raw materials are stored in very large silos or warehouses. The material is in piles, often settling in irregular shapes, which makes it difficult for end users to assess inventory levels. BinMaster’s 3DLevelScanner system with its unique multi-point surface mapping capabilities reliably and accurately measures the volume of the stored raw mix in many types of silos, warehouses, or open bins.

Blending and Storage Silos
Application: A homogenous mix is stored in silos as part of the raw material homogenization process.

Challenges: The raw materials are stored in large silos. The material settles irregularly, making it difficult for operators to assess true inventory levels. The BinMaster 3DLevelScanner with its unique multi-point surface mapping capabilities reliably and accurately measures the volume of stored mix in the silos. In addition, the 3DLevel-Scanner’s optional 3D visualization tool allows operators to see the mix distribution inside the silos in real time.

Filter (ESP)
Application: Fly ash is captured and removed from the flue gas by electrostatic precipitators or fabric bag filters located at the outlet of the furnace and before the induced draft fan. The fly ash is collected in hoppers below the precipitators or bag filters and periodically removed from them.

Challenges: ESP hoppers are continuously filled with hot fly ash. The combined effect of humidity and temperature causes the fly ash to stick to the sides of the hopper. This can cause material buildup and clogging of the hopper which in turn can damage the ESP plates. Continuously monitoring and understanding the distribution of fly ash in the hoppers is extremely important for end users. With accurate, real-time information at hand, preventive action can be taken to empty the hoppers on time, and to clean and perform maintenance work if and when necessary. This is essential in order to prevent clogging and risk of damage to the ESP plates. Damaged plates can create environmental and health concerns as well.

3DLevelScanner technology is the only currently available technology that permits continuous volume level measurement of fly ash inside an ESP hopper. The optional 3D visualization tool allows end users to see the actual allocation of material inside the hopper and detect buildup as it occurs, facilitating the scheduling of timely maintenance to avoid unexpected and costly interruptions of the process and damage to the ESP plates.

At plants where 3DLevelScanner technology is not used in the ESP process, the emptying of the hopper may not be connected to the filling process. There is no reliable way to measure the amount of fly ash in the hopper, so a timer is set to begin emptying regardless of the amount of fly ash remaining in the hopper. This makes the process very inefficient and causes (for example) the air compressors to work unnecessarily. The 3DLevel-Scanner allows users to reliably coordinate and automate the filling and emptying of ESP hoppers.

Coal Storage
Application: Coal is stored in silos which feed the coal to the kiln.

Challenges: The coal silos hold several hours supply of coal which is fed into the coal handling system which supplies coal to the kiln. If a coal silo were to be completely empty, the kiln would need to be shut down. Therefore, end users seek the best technology to give them continuous and accurate readings regarding how much coal is in a given silo. BinMaster’s 3DLevelScanner provides accurate measurements even in the extremely dusty and harsh conditions characteristic of a coal storage environment.

Clinker Storage
Application: The raw mix is fed into a pre-heating tower at 1472°F (800°C) before returning to the vertical rotary kiln where it is heated to a temperature of 2642°F (1450°C). Combustion causes a chemical reaction called decarbonation which releases CO2 contained in the limestone. The fired materials take the form of hard granules called clinker, which resembles pellets about the size of marbles. Following re-cooling, clinker is stored in silos, and then transformed into cement according to production requirements.

Challenges: Clinker silos generally are very large diameter silos that hold tens of thousands of tons of material. The material is very dusty and fed into the silo at a relatively high temperature of approximately 212°F (100°C). The end user’s challenge is to know the amount of clinker stored in the silo. The BinMaster 3DLevel-Scanner system can provide an accurate volume measurement in any size of clinker silo, with its optional 3D visualization allowing the end user to view how the material is distributed inside the silo and to continuously monitor inventory levels. The HE model of the 3DLevelScanner for harsh environments is ideal for clinker silos.

Additives Storage
Application: Limestone is combined with clay, ground in a crusher and fed into the additive silos. Sand, slag and fly ash are then mixed together with the limestone and clay in carefully controlled proportions and ground into a fine powder in a roller mill.

Challenges: The end user’s primary challenge is to carefully control the amount of additive that is added to the cement manufacturing process. Slag and fly ash can be extremely dusty and are prone to variable topography as they are loaded and discharged from the silo. Sand may not flow freely dependent upon the amount of moisture present and the particle size and shape. Using dust-penetrating, multiple point measurement technology, the 3DLevelScanner accurately tracks the amount of additives in inventory allowing the end user to manufacture efficiently and to calculate cost-of-goods sold with improved confidence.

Cement Storage
Application: Finished cement is stored in silos before being delivered in bulk using tanker trucks or packaged into bags.

Challenges: The finished cement is a fine powder material that creates a very dusty environment during the filling process. It is commonly stored in large silos where buildup can occur, making inventory management and control even more challenging. By measuring multiple points in the silo, BinMaster’s 3DLevelScanner can accurately determine the volume of stored cement, performing reliably in the extremely dusty, harsh environment.

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