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UWT (UK) Ltd Delivers Level Controls to a Calcium Carbonate Processing Plant March 08, 2013

UWT (UK) Ltd Delivers Level Controls to a Calcium Carbonate Processing Plant

Some typical uses for CaC03

Paper, Plastics, Paints, and Coatings:

Calcium carbonate is the most widely used mineral in the paper, plastics, paints and coatings industries both as a filler, and due to its special white colour as a coating pigment.  In the paper industry it is valued worldwide for its high brightness and light scattering characteristics and is used as an inexpensive filler to make bright opaque paper.  Filler is used at the wet-end of paper making machines and calcium carbonate filler allows for the paper to be bright and smooth.  As an extender, calcium carbonate can represent as much as 30% by weight in paints.  Calcium carbonate also is used widely as a filler in adhesives, and sealants.

Personal Health and Food Production:

Calcium carbonate is used widely as an effective dietary calcium supplement, antacid, phosphate binder, or base material for medicinal tablets.  It is also found on many grocery store shelves in products such as baking powder, toothpaste, dry-mix dessert mixes, dough, and wine.  Calcium carbonate is the active ingredient in agricultural lime, and is used in animal feed.  Calcium carbonate also benefits the environment though water and waste treatment.

The Brief:

UWT (UK) Ltd’s partner SN Engineering received a brief to design and deliver a facility that would accept and store the raw bulk material before being conveyed to the grinding and classification process.  Following processing, the sub 75µm finished product was to be conveyed and stored in a pair of 2600m³ bulk storage silos.  UWT (UK) Ltd were partnered with SN Engineering to supply the process control for continuous monitoring of the silo levels using Nivobob series and overfill protection via the use of Rotonivo 3000 series of the rotary paddle switches.

The Nivobob plumb-bob systems were selected due to their ease of installation, ease of commissioning and complete reliability.  The Rotonivo 3000 series was selected as a back up system to protect against overfilling, this rotary paddle switch offers complete security in durability and ease of use.

Application Challenges:

A level control product was required that could guarantee a trouble free operation and straightforward commissioning.

The bulk solids material in this application presented the challenges of:

Lime powder – an aggressive and very dusty material
Aggregates – aggressive, high load

Nivobob Attributes:

Discontinuous level measurement of bulk goods and interface measurement
Simple and reliable measuring principle
Sensor weights in various designs suitable for every application
Insensitive to dust, dielectricity, conductivity, humidity, caking
Easy installation, maintenance-free operation
Very precise results covering large measuring ranges
Suitable in hazardous locations (dust explosion)
Detection of solids in liquids
Suitable for interface applications
Increased durability via brushless motor also with high measuring frequency
Large measurement distances and long intervals between
A multitude of different process connections and accreditations ensure that Nivobob is suitable for the international market

Rotonivo Attributes:

Rotating paddle switch suitable for most bulk goods
Simple and reliable measurement principle, maintenance free
Insensitive to dust, electrical charge, adhesion, temperature and pressure
Suitable for Hazardous Locations (dust explosion)
Small and compact design, requires little space
Swivelling housing for simple installation
Robust die-cast aluminium housing
Enclosure IP 66
Variety of supply voltages and process connections available

The Result:

The first phase of commissioning for this new carbonate processing plant took place in October 2012.  The client has acknowledged complete satisfaction with the quality of service and products delivered by SN Engineering and partner, UWT UK Ltd.


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