Lesson 6: Sedimentation
Sludge accumulates at the bottom of the tank/basin. Typical tanks or basins used in sedimentation include conventional rectangular basin, conventional center-feed basins, peripheral-feed basin, and spiral-flow basins. In conventional treatment plants, the amount of detention time required for settling can vary from 2 to 6 hours.
اقرأ أكثر
Thickener Feed System Design
Optimize flocculation conditions. Evenly distribute the feed stream into the thickener. It is critical to introduce the incoming thickener feed in an even and concentric manner in …
اقرأ أكثر
Conventional Thickeners
Conventional Thickeners are generally incorporated in heavy duty applications when the underflow density is high and substantial torques are required to convey the settled …
اقرأ أكثر
High Capacity Thickener
Conventional practice is to add flocculant as a dilute solution to the feed slurry in a launder or feed pipe, possibly using staged addition so as to improve ... Flocculant use was comparable in most cases to that which was employed in conventional thickeners operating at a much lower throughput per unit area. ... Feed to the Hi …
اقرأ أكثر
Conventional Gravity Thickeners
High rate thickener units are provided in sizes ranging from 5' to 250' in diameter, and can accommodate drive head torques of up to 4 million foot pounds. They are available in shaft or cage driven models. Shaft drive thickeners can be truss or beam supported for heavy duty applications. A heavy duty drive unit with precision bearing and gear ...
اقرأ أكثر
Conventional thickener THK
Thickeners are utilized in various solid/liquid separation processes in order to increase the density of a process stream. Feed solids concentration is the single most important variable affecting the …
اقرأ أكثر
Gravity clarification and thickening
Both the filtrate and the thickener overflow are usually recycled into the plant feed as shown. 5.1.1 Design and scale-up of conventional one-pass clarifiers The design overflow rate (flow rate per unit area of liquid surface) in conventional one-pass clarifiers is usually from 1 to 3 m/hour, depending on the degree of flocculation.
اقرأ أكثر
How a Thickener Works
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 ...
اقرأ أكثر
Thickeners
The quality of solids to be handled. Usually expressed as area per unit weight of dry solids per day. High rates usually require a combination of a stronger thickener mechanism and a lifting device. …
اقرأ أكثر
DEWATERING * CONVENTIONAL AND HIGH-RATE …
A comparison of factors associated with conventional and high-rate thickeners is summarized in the table. As slurry is fed to a high-rate thickener, dilute flocculant is …
اقرأ أكثر
Most common problems in thickener operations (part 1)
Figure 1. Conventional thickener. Depending on the configuration of the plant, the type of mineral and the thickener technology, the recovery of water can vary between 65% to 95% of the process water, as shown in figure 2. Figure 2. Water balance of a high-density thickener in an iron ore concentrator plant
اقرأ أكثر
DEWATERING * CONVENTIONAL AND HIGH-RATE …
The density of the thickener underflow is a good indicator of the balance between the feed rate and the discharge rate. A high density is achieved by allowing the sludge bed in the …
اقرأ أكثر
High Capacity Thickener
High Capacity Thickener. Previous. Next. Conventional practice is to add flocculant as a dilute solution to the feed slurry in a launder or feed pipe, possibly using staged …
اقرأ أكثر
Density Current Baffles (Stamford Baffles) | Enduro
For this condition, calculating horizontal projection and baffle size should also include the launder width. The minimum size should be 24" diagonally. 2. Sloping baffle inward and downward beyond the scum baffle to redirect random density currents (flows) toward the center of the tank. 3. Mounting baffle continuously around the tank to ...
اقرأ أكثر
How to Operate a Thickener
Put the bottle down into the thickener as deep as you want it, then pull out the cork with the string. Wait a second for the bottle to fill, then pull it up, and there's your sample. Then measure the distance on the stick, and this will show you how deep down the sample was taken in the thickener.
اقرأ أكثر
Solid – Liquid Separation – Thickening
The feed launder terminates in a feed well located at the centre of the tank. The feed well is designed to break the fall of the slurry and dissipate the energy. Download : Download full-size image; Figure 14.1. Sketch of a Thickener Showing the Access Bridge, Feed Well, Rakes Supported by the Central Column and Cables and the Underflow …
اقرأ أكثر
(PDF) Modeling industrial thickener using computational …
Flow rate of the launder and bottom of the thickener verses the feed flow rate, 22.5% as solid percent. Height of settled bed verses the feed flow rate, 22.5% as solid percent.
اقرأ أكثر
Thickening | SpringerLink
In a Conventional Thickener the feedwell is located in the upper part of the tank. When the feed enters it, it is diluted to the so-called conjugate concentration by an upcoming flow of water. The diluted suspension settles at a constant velocity to form sediment at the bottom of the tank. Figure 8.12 shows a scheme of a conventional …
اقرأ أكثر
Raking in gravity thickeners
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 …
اقرأ أكثر
Thickener Selection Parameters
In conventional thickeners, feed wells are cylindrical, and frequently baffled. In Lamellas and other types of thickeners, the feed wells can be an adjacent tank, a rectangular …
اقرأ أكثر
Flow rate of the launder and bottom of the thickener verses the feed
Download scientific diagram | Flow rate of the launder and bottom of the thickener verses the feed flow rate, 22.5% as solid percent. from publication: Modeling industrial thickener using ...
اقرأ أكثر
Lamella Settler
The Lamella Settler consists of 4 major compartments positioned along a rectangular settler tank with an inclined backside at a slope of 45-60 degrees. The sections are: A central slurry feed launder with a feed connection. Two plate pack compartments with overflow launders that straddle the feed launder. Each stack consists of a set of plates ...
اقرأ أكثر
Thickener upgrade incorporating feed system innovations …
This modification facilitated dilution of the thickener feed stream, reducing it from a maximum of 16.6%w/w to 10.3%w/w feed solids concentration. ... The feed slurry entered the thickener with high-velocity launder flow, carrying substantial volumes of froth and entrapped air. This resulted in surging, burping, splashing, and a challenging ...
اقرأ أكثر
Conventional or High Capacity Thickeners
more than 10 times compared to conventional thicken capacity thickener will significantly reduce the foot higher concentration of underflow, clearer overflow
اقرأ أكثر
Clarifiers & Thickeners
conventional center feed clarifier Higher Overflow Rates - resulting in reduced foot print / less number of units Eliminates Short circuiting, permitting full utilization of tank volume and reduction in surface area by as much as 50% as compared to conventional center feed unit Peripheral Feed Launder Peripheral Discharge Launder
اقرأ أكثر
Difference Between Clarifier and Thickener
The dense Thickener solids are raked to the thickener's underflow cone and are removed via a slurry pump through the underflow pipe. Underflow slurry densities can vary based on the type of material being processed, size distribution of solids being settled, or other process factors but as a general rule, range from 35-50% solids by weight.
اقرأ أكثر
Conventional thickener THK
Thickeners are utilized in various solid/liquid separation processes in order to increase the density of a process stream. Feed solids concentration is the single most important variable affecting the sedimentation properties of a given slurry. Conventional thickener. ANDRITZ process engineering will determine the optimum percentage of feed ...
اقرأ أكثر
Most common problems in thickener operations (part 1)
Part 1 will cover problems in thickener operations caused by thickener design errors and changes in ore properties. Part 2 will discuss in detail the problems caused by …
اقرأ أكثر
Feedwell is the heart of a thickener
AMIRA conducted a CFD study of this two stage feedwell, similar to that reported in their P266 project. The results are shown in Figure 5. The design tested was for a 14.5 m feedwell in a 100 m high rate thickener. The inner feedwell diameter is about 8.5 m. The flow rate was varied from 9,000 to 17,000 m3/h.
اقرأ أكثر
MAGRA HIGH-RATE THICKENER – Magra Process …
global leader in high-rate thickeners. 100+ times smaller footprint with comparable flocculant consumption to conventional rake thickeners and no moving parts. Feed densities up to 55 % discharging underflow at 70 % (solution could be halved) – no other thickener can compare.
اقرأ أكثر