Concrete is fundamental to our modern-day construction and a key part of our global economy. Concrete is an artificial stone-like material used for various structural purposes. It is made from a mixture of water, cement and aggregates such as gravel, sand and stone, and then drying by hydration. Water and cement combine to be a “binder” and the aggregate, sand and gravel are the “filler” that is bound together with the “binder”.
Concrete is everywhere! It is used for roads, sidewalks, houses, bridges, skyscrapers, pipes, dams, canals, missile silos, and nuclear waste containment. There are even concrete canoes and Frisbee competitions. It is strong, inexpensive, plentiful, and easy to make. But more importantly, it’s versatile. It can be molded to just about any shape.
Concrete is friendly to the environment. It’s virtually all natural. It’s recyclable. It is the most frequently used material in construction. Slightly more than a ton of concrete is produced every year for each person on the planet, approximately 6 billion tons per year. By weight, one-half to two-thirds of our infrastructures are made of concrete such as: roads, bridges, buildings, airports, sewers, canals, dams, and subways.
But exactly how are we storing all this dry cement and how are we measuring the amount of cement in these storage facilities? That is the subject of this blog post. We’ll look at the storage of cement (and other dry materials) and the use of level indicators.
Dry Bulk Material (cement) Storage
There are different types of cement silos such as the low-level mobile silo and the static upright cement silo, which are used to hold and discharge cement and other powder materials such as fly-ash. The low-level silos are fully mobile with capacities from 10 to 75 tons. They are simple to transport and are easy to set up on site. These mobile silos generally come equipped with an electronic weighing system with digital display and printer. This allows any quantity of cement or powder discharged from the silo to be controlled and provide an accurate indication of what remains inside the silo. The static upright silos have capacities from 20 to 80 tons. These are considered a low-maintenance option for the storage of cement or other powders. Cement silos can be used in combination with batching plants, truck (cement carriers) loading station for distributing the cement.
Cement can be stored in different types of silos like horizontal mobile silos, concrete silos, steel panel Silos etc. depending upon the requirement of the end user. While Mobile Silos come in a relatively small storage capacity of approximately 90metric tonnage of cement, Concrete Silos can store practically thousands of metric tonnages of cement. The majority of silos that store more than 5000 metric tonnages of cement are constructed from concrete. A good compromise between cost, construction time and ease of operation is steel panel silos. These silos can be manufactured in a factory, and then erected at site using small panels that are bolted together to form a silo that is watertight because of a sandwiched layer of special rubber seals.
On board of ships the cement is stored within Pressure tanks, Atmospheric hoppers or the cargo holds of the ship. The volume of these storage possibilities can vary from 10 to 40.000 Tonnage. Storage within the pressure tanks be used for the smaller volumes, which are commonly used on board of offshore related ships and rigs. The larger volumes of dry material will be stored within the cargo holds of bulk carriers or self-discharging cement carriers between the mainly the 500DWT and 40.000DWT.
Storage tanks, silo’s or Bin level indicators are used in applications as described above:
In storage tanks, silo’s or bin the level indicators will be used for high level monitoring and possibly low level monitoring. High level monitoring uses point level sensors to detect and indicate the presence or absence of material at the desired high point in silos, bins, pressure tanks or atmospheric hoppers.
For Bulk materials in small up to large vessel heights a sensor for continuous measurement of bulk materials under different process conditions can be a Radar sensor. It is ideal for level measurement in very high silos, large bunkers and segmented vessels. Thanks to the very good signal focusing a simple setup and reliable measurement is ensured. The Radar sensor can be equipped with an encapsulated plastic antenna or a lens antenna integrated in the metal flange. This enables the optimum adaption to different application areas.
Benefits of a radar sensor
- High plant availability, because wear and maintenance-free
- Maintenance-free operation through non-contact measuring principle
- Reliable measurement independent of vapor, dust and noise
For powdery and fine-grained bulk materials for density: > 0.008 g/cm³ (0.0003 lbs/in³); granulation size: max. 10 mm (0.4 in) the Vibrating level switch with suspension cable for powders for universal use in powders and fine-grained bulk materials can be used. The level switch detects reliably and robust the min. or max. level. The tuning fork is ideal for use either in adhesive and abrasive products as well as in bulk solids with very low density. The position of the switching point is determined through the length of the suspension cable.
Benefits of a vibrating level switch
- Low costs for maintenance through robust design
- Minimum time and cost expenditure thanks to simple setup without medium
- Reliable function through product-independent switching point
Guided Radar Level Sensor
This sensor is commonly used in (smaller) silo’s, pressure tanks and hoppers mainly for Light and heavy-weight bulk dry bulk materials, applications with strong dust generation, condensation or buildup
This guided radar level sensor measures maintenance-free light and heavy-weight dry bulk materials. Even in applications with strong dust generation, condensation or buildup, the sensor delivers precise and reliable measured values.
Benefits of a guided radar level sensor
- The guided adjustment enables a simple, time-saving and reliable setup
- Short enable probes offer a simple standardization and highest flexibility in the planning
- Virtually all bulk solids can be measured with the automatic probe end tracking
Level indicators are an integral part of the production, storage and operation of cement and concrete plants and storage applications. They are critical to the protection against costly spills from overfilling and against material outages. In addition, continuous level sensors are used for inventory management of critical materials such as cement and flyash in the concrete production process. In the inventory monitoring area the weight & cable inventory monitor is one of the most common that is used by concrete batch plants and on board of dry bulk ship to monitor fly-ash, cement and other dry materials.
If you would like to know more about the different kind of level indications or you would like to discuss the best possible level indication for your application contact us via the comment box below or fill in the contact form via contact.