Design and building a thickener
Thickener is designed and manufactured for the treatment of mines, such as iron, copper, aluminum, stones, ceramic and sand tile factories. Since the waste water from these industries contains high suspended solids and high TSS, designing and constructing a thickener can be used to refine water in the production line, and to create high savings in operating costs of the production units.
In the design and construction of the thickener, the input wastewater has high solids and due to the difference in the density between the particles and the liquid, these particles are deposited and discharged from the bottom of the reservoir in the form of a Concentration Flow or Underflow. The treated water goes out in the overflow stream. In total, in designing and constructing a thickener, you can calculate the diameter and height using mathematical modeling and engineering software.
Describing the process of design thickener
Thickener is used in the mineral industry, sandstones, stones, and ceramic tile industries to reduce the percentage of solids in the slurry of the production unit. With the design and construction of the thickener, the amount of solids and suspended particles can be reduced and the treated water can be used for industrial or agricultural use.
In the design and construction of the thickener, in general, the flow of the wastewater is divided into the two sections of overflow and underflow. In the following, a general description of this process is shown
Several major assumptions are considered for modeling unit operations in the design of the thickener :
1. It is assumed that all particles are finite and have the same density.
2. It is assumed that there is no mass transfer between particles and fluid.
3. The input slurry is completely suspended and the particles are fully flocculent.
4. All particles are homogeneous.
5. We ignore fluid-fluid stress versus fluid-solid stress.
6. The fluid is considered elastic.
The basis of the thickener design is the use of gravity to separate solid particles from water. Generally, every particle inside the thickener is affected by three forces.
A) The gravity of the earth that drives the particles down: the larger the particle mass, the more gravity will be.
B) the floating force that drives particles upright, based on the Archimedean principle.
C) Drug force, which is the friction of moving a particle within a fluid.
Therefore, thickener should be designed in such a way that the gravity force is greater than the sum of the drug and float forces and thus the particles are deposited on the thickener floor.
Initial experiments on the thickener design
When a portion of the slurry, the iron ore, the gold mine, the sandstone, the ceramic tile plant, or the stone containing the solid particles, are poured into a cylindrical unit, we should wait for a period of time until the suspended particles are deposited then you can draw a graph similar to the one below. This graph, which is the basis for the design and construction of a thickener, is the term of deposition rate graph.
Software for designing and manufacturing of a thickener
Similar to what is found in the sedimentation rate test, the fluid is divided into two parts in the thickener, one is the lower layer (Hindered settling), in which the concentration of solid particles is higher than the critical concentration, and there is solid fluid flux. The outlet of this part, which is located on the bottom of the thickener tank, contains high-percentage solids that are discharged as far as it is.
The higher layer, called free settling, has a much lower concentration, and eventually, at the top of this layer, a stream of overflows occurs. The output of this section is the same as the refined wastewater of the thickener unit, with the percentage of solids being reduced.
Using mathematical modeling in designing and constructing a thickener, height and diameter can be calculated. The collection of this information is being prepared in the thickener design engineering software to help engineers working on the construction of thickener & clarifiers in the mineral industry such as copper, iron, gold, aluminum, as well as ceramic tiles and mosaics and
Thickener unit parts in designing and construction
The most important components and structures of a thickener that must be carefully designed prior to the construction work include:
• The Thickener’s total weight maintenance structure is designed and constructed according to economic estimates, structural dimensions and fluid weight in metal or concrete.
• The main cylinder with the bottom hopper is the most important part of the thickener.
• The Feed Well, which is responsible for the uniform distribution of the flow of input into the thickener
• The drain and mixer set up in the design and construction of the thickener is responsible for the transfer of sludge or condensate drainage on the tank floor.
• Overflow that is designed and constructed by grooves to drain the flow of water thoroughly from the thickener.
Requirements and applications of designing and manufacturing of a thickener
Requirements and applications of designing and manufacturing of thickener in the mineral industry, water is used as one of the most important raw materials in the processes of production, extraction, crushing and processing. Generally, in mines of iron, copper, gold, aluminum, and many other mineral stones, a lot of water during the manufacture and production of minerals is consumed.
In the sand washing industry, as its name implies, a large amount of water is used to produce sand, which ultimately makes the water darker and cloudier.
In the stone industry, in the cutting and polishing sectors, stones are used to a large extent, so that the cutting dust is not released into the atmosphere and the polishing quality is increased. As a result, the carbonaceous effluent contains solid particles that are suspended and very thin.
In the tile, ceramic and mosaic industry, water is also used as a substance in the manufacture and production of a variety of products in slurry and wear and finishing processes.
In total, the waste water from all these industrial units is contaminated with solid particles and should be refined in the thickener unit to be reused in the production line. Briefly, the design and manufacturing of the tools for the following industries are:
• Mines and factories of mineral processing such as gold, copper, iron, stone
• Stone cutting
• Sand washing
• Ceramic tile factories
• Waxing factories
Benefits and results of making a thickener
The most important advantage of using thickener in the mineral, stone and ceramic tile industries can be refining and reusing water as well as reducing TSS. Water as a national capital is returned to the beginning of the production line by way of this method, which, while reducing water consumption costs, also protects the environment. Generally, the advantages of designing and constructing a thickener in the industry are as follows:
• Saving water consumption and reducing current costs of the unit
• Returning refined water to the beginning of the production line with correctly designing and constructing a thickener
• The area of land used is very limited to replace waste dumps or wastewater evaporation tanks
• The possibility of reducing mold or sludge outlet to the almost dry powder by means of a press filter
• Easy navigation and maintenance.