A common variant on the gravity thickener design is the picket fence thickener. This technology is fitted with a stirrer comprising a series of relatively closely-spaced vertical arms, and is therefore similar in appearance to a picket fence. For both designs, the sludge enters the centre of a cylindrical tank and flows out to the periphery.
Figure 2 – Shows computational fluid dynamics comparisons of feedwells and their impact on thickener distribution. To highlight the variables in designing a CCD circuit, we will consider different recovery estimates based on an ore leach followed by CCD. Table 1 outlines the base data for a three-stage CCD with high-rate thickeners.
THICKENER DESIGN, SIMULATION AND CONTROL By F. Concha, J.P.Segovia, D. Sbarbaro and R. Bürger ... In addition, at the beginning of the test, where reliable data are needed, it is difficult to ...
Where there is little significant effect of compression factors, the bed depth can be selected based upon operating characteristics of the thickener installation. In this case, information must be available (or assumed) concerning the normal fluctuations in feed rate and concentration. Also, sludge storage requirements should be considered. For …
Keywords: elevated tank, thickener, ASCE 7, liquid storage, slurry, sloshing . 1. INTRODUCTION Outotec Pty Ltd designs mining and industrial thickeners for Australia and overseas. A common tank design is a cylindrical steel shell with a truncated conical bottom elevated above ground on steel columns. An example of a typical thickener tank ...
This paper presents a development of thickening theory which provides a reliable and easy-to-use method for determining the size of continuous thickeners from …
The Dorr torq thickener is a new development in the unit thickener field. The raking mechanism is supported from a stationary central pier on which the driving motor and gear reduction are mounted. The feed may be introduced at the center through a launder suspended above the top of the liquid leavel or by means of a siphon feed through the ...
The guidelines in this article apply to organic thickeners and rheology modifiers: hydroxyethylcellulose (HEC), hydrophobically modified HEC (HMHEC); hydrophobically modified alkali-soluble emulsions (HASEs); and nonionic synthetic associative thickeners (NSATs), a general category that includes the familiar "urethanes" …
Computational fluid dynamics (CFD) is a powerful tool for optimizing the design and performance of unit operations used to achieve particle aggregation and sedimentation. Early CFD feedwell modeling gave predictions on the solids and fluid flows, which were useful for identifying discharge asymmetry and short-circuiting currents, but …
The pilot-scale thickener facility used in this study is a closed loop system and is shown schematically in Fig. 1.A sample of slurry is mixed continuously in a 4.5 m 3 mixing tank, and pumped out of the mixing tank underflow into the pilot thickener. The thickener tank is a 2 m diameter by 2 m high side wall tank with a 14° floor and a small …
Equipment Design. There are three main types of thickeners/clarifiers: bridge support, column support, and traction. In a bridge support thickener, such as the one shown below, the rakes and drive mechanism are …
FIG. 7.46.2 Gravity thickener design data plots. Data plot procedure: 1. Conduct settling tests at various initial solids concentrations (a through d in panel A), covering the range of expected thickener influent solids concentrations; 2. Determine the settling velocity Vs for each concentration as the slope of a line tangent to the initial ...
Based on the dry feed rates to each paste thickener as 7920 and 4320 t/day, the thickener's diameters were determined as 23.9 and 16.1 meters which are similar to the actual thickener's ...
How DAF works. Dissolved air flotation (DAF) provides thickening of sludges (i.e. thickens the sludge) by encouraging the solids to float to the surface, rather than allowing them to sink as in gravity thickening.. DAF is applied to increase the sludge solids concentration when these solids are neutrally buoyant (i.e. neither sink nor float) and so …
Steady-state analyses and methods of thickener design that are essentially based on Kynch's theory include the papers by Talmage and Fitch (1955), Hassett (1958, 1968), Moncrieff (1963/64), Wilhelm and Naide (1981), Lev et al. (1986), Waters and Galvin (1991), Yong et al. (1996) and Chancelier et al. (1997), see also the reviews by Concha …
The torque capability of a thickener drive is specified as Duty Rating being the maximum mechanism design strength or the setting on the Torque Control Box. The torque, in turn, depends on a K factor and the thickener diameter based on the following formula: Torque (in Nm) = 14.6*K*D 2 (in meters)
Consider the design of an industrial thickener for a feed rate of 178 tons per hour, with an underflow concentration of 57.3% of solid by weight of a copper tailing with the following properties: ... This contribution summarizes, and applies to experimental data, a recent approach [Bürger, R., Diehl, S., 2013. Inverse Problems 29, 045008] for ...
As always, pilot or large-scale tests, if properly conducted and evaluated, yield the best test data for thickener design. 5.2.2 Applications, construction and types of gravity thickeners Most of the applications of gravity thickeners are in mineral and coal processing, and in waste water treatment.
Table 3.2.1 Step-by-step approach for the design of settling-thickening tanks Step 1 Establish design criteria Step 2 Calculate surface area Step 3 Calculate thickened sludge volume Step 4 Determine tank dimensions Step 5 Configure inlet and outlet Step 6 Operation and maintenance Step 1: Establish design criteria
4.11 Design Example 23-58 5.0 GRAVITY BELT THICKENER 23-60 5.1 Evaluation and Scale-Up Procedures 23-61 5.2 Process Design Considerations and Criteria 23-62 5.2.1 Unit Sizing 23-63 5.2.2 Other Design Considerations 23-64 5.2.3 Mixing Design 23-64 5.2.4 Flocculation Design 23-64 5.2.5 Belt Speed Design 23-65 5.2.6 Plow Design 23-65
The thickener is a circular unit. The sludge suspension is introduced into the centre, inside the centre well. ... polymer flocculation can be of considerable interest in order significantly increase the flow rates tolerated by the thickener. Table 1 provides a few design data applicable to the different types of sludge.
The innovative paste-thickener design facilitates highly clarified liquid recovery as well as maximum underflow densities. 3 Cost-effective solid-liquid separation with crystal clear overflow VARIETY AND AVAILABILITY Thanks to the thickener's innovative, modular design, ANDRITZ is able to offer a wide range of thickeners and ...
In very simple words, a thickener is a machine that separates liquid from solids. It is defined as a method of continuous dewatering of a dilute pulp, wherein a regular discharge of a thick pulp takes place which is of uniform density, concurrently with an overflow of clarified solution.
The AMIRA P266 'Improving Thickener Technology' series of projects has sought to provide a firm scientific basis for feedwell and thickener design, a requirement as pressures on water usage in the ...
A thickener is an equipment structure used for the continuous gravity settling (sedimentation) of solids in suspensions. Suspension is fed into one or more basins or chambers and, whilst it is …
LABORATORY TESTING FOR DESIGN OF THICKENER CIRCUITS Joseph M. Keane K D Engineering Co., Inc. 1844 W. Grant Road, Suite 106 Tucson, Arizona 85745 ... and Naidel (1979) utilizes data from the graduated cylinder batch sedimenta- tion tests with the addition of rakes rotating at a very slow speed to attempt to achieve the maximum density ...
Similar to the digesters, there are two design approaches in thickeners too: 1. Design based on experience. 2. Design based on Iaboratory data. 1. Design based on experience Solids throughput is an important criterion in the design of thickeners. The design is mostly based on the solids flux, i.e. kg solids/h/m2. Typical flux values are given ...
A thickener operates pretty much like a settling tank. The feed enters from the middle, are distributed radially, the settled sludge is collected from the underflow, and the effluent exits over the s. In a continuously operated thickener, there are different zones of concentration. The topmost zone is free of solids and
Thickener Operation. Figure 13 shows a log-log relationship between underflow concentration and unit area at various interface heights for a desulfurization sludge. This graph was made from the data …
CURRENT THEORY AND THICKENER DESIGN. Bryant. Fitch; Cite this: Ind. Eng. Chem. 1966, 58, 10, 18–28. Publication Date (Print): October 1, 1966. Publication History. ... Steady state thickener modelling from the compressive yield stress and hindered settling function. Chemical Engineering Journal 2005, 111 (2-3) ...
Thickener solids loading rates vary with the type of sludge. Some typical solids loading rates are given below in Table 12-2. These values shall be used for design unless other acceptable data are submitted. For loading rates of other type sludges, refer to Table 5.2 of the EPA Process Design Manual-Sludge Treatment and Disposal. Table 12-2
gravity belt, or centrifuge thickener. • Solids concentrations in the thickened solids are usually lower than for a DAF, gravity belt, or centrifuge thickener. DESIGN CRITERIA Preliminary Bench-Scale Study If representative samples of wastewater solids are available, laboratory bench scale testing should be conducted to determine design ...
The purpose of this paper is to present a generalised understanding of the various inputs that combine in the design, control …
The simulation results showed good agreement with the operational data. Computing mesh for the industrial thickener. Flow rate of the launder and bottom of the thickener verses the feed flow rate ...
This chapter presents different theories of thickener design. These theories have been applied to the solution of the same problem, wherever applicable, to reveal …
Thickener Sizing Calculator valid for settling thickeners, high rate thickeners, and clarrifiers. Exit Thickener Calculator. Process Input. Parameters. Value Units. ... Mechanical Design. Description. Value Units. Drive Motor Speed: [rpm] Rake Tip Speed: [m/min] Rake Drivetrain Efficiency:-Required Drivetrain Reduction Ratio:-Required ...
This chapter covers the design and operation of gravity thickeners, dissolved air flotation thickeners, centrifuges, and gravity belt thickeners for wastewater treatment. It includes …
doi: 10.1007/978-81-322-3634-4_20 ++. Chapter 20. Design of Thickeners. Abstract This chapter presents different theories of thickener design. These the-ories have been …
Thickener outputs can accommodate a range of tailings disposal options from low yield stress, easily . pumped ... for informed use of data for design or optimisation.
The data in the table below have been collected for the settling of flocculated suspensions using dilutions of 2:1, 3:1, and 4:1. a) Plot the data and determine the settling rate of the suspension at each dilution. In each case, the settling rate should be determined graphically from the straight-line portion of the plot before compression begins. b) The final dilution …