Operating principle:
The purpose of separation is to separate out substances with different mass ratios from mixed fluid.Separation forms included solid-liquid separation,liquid-liquid separation and liquid-liquid-solid separation.
When mixed fluid enters rotating bowl of centrifuge through feed tube ,solids with larger density would rapidly deposit on inner wall of the bowl,forced by centrifugal acceleration.Then spiral pusher pushed deposited solids to taper end of the bowl,and discharges them out of centrifuge from residual outlet.Meanwhile ,liquid phase with smaller density forms a liquid ring layer and discharges from bowl through overflow port,the bowl and spiral pusher run at a high speed simultaneously ,for there exists speed discrepancy,deposited solids on the wall of bowl could be conveyed to residue outlet by spiral pusher.This separation process carry out continuously.
Separation technique
Feeding-gravitational separation-liquid discharge-sediment discharge.
Separation effect factors Centrifuging factor ,length to diameter ratio of cavity ,depth of fluid pool.
Field control
Bowl rotating speed ,rotative speed difference,between,spiral pusher and bowl depth of liquid pool.
The feed product is pumped into the decanter centrifuge through an inlet. Feed into a horizontal bowl and then rotate. The bowl consists of a cylindrical portion and a conical portion. The separation takes place in the cylindrical part of the bowl. Fast rotation produces centrifugal forces of up to 4000 x g. Under these forces, solid particles with a higher density are collected and compacted on the wall of the bowl. The scroll (also a screw conveyor or screw conveyor) rotates inside the bowl at slightly different speeds. This speed difference is called a differential speed. In this way, the scroll conveys the precipitated particles along the cylindrical portion of the bowl to the conical end of the bowl. At the smallest end of the conical portion of the filter bowl, dehydrated solids leave the filter bowl through the discharge port. The clarified liquid exits through the mating disc (internal centrifugal pump).
Decanter centrifuges process characteristics The separation process in a decanter centrifuge relies on a few process characteristics such as centrifugal force or force, sedimentation rate and separating factor, differential speed between the conveyor and bowl, and clarity of the liquid discharge. Decanter centrifuges require a centrifugal force for the separation of the solids from the liquid. This characteristic is dependent on the radius of the centrifuge and its angular rotational speed. A decanter centrifuge applies a force equivalent to several thousand , which reduces the settling time of the particles. It is also favored to maintain a large force, which will result in an improved separation. The rate at which sedimentation occurs is an important characteristic of the decanter centrifuge separation process. The sedimentation rate is influenced by the particle size, the shapes of the particles, their differential densities and the viscosity between the particles and the liquid. This process characteristic can be improved by utilizing flocculating agents. The sedimentation rate is also dependent on the separating factor of the decanter centrifuge, which is related to the centrifugal force. The exterior bowl and the scroll conveyor rotate at different high speeds. This differential speed between the two is accountable for the sedimentation throughout the decanter centrifuge cylinder. A high differential speed results in a smaller residence time of the cake settlement, so it is necessary to keep the cake thickness to a minimum to avoid impairing the discharge quality. Keeping the cake thickness to a minimum also aids in the improvement of the cake dewatering process. For this reason, it is necessary to obtain an optimal differential speed to balance the cake thickness and quality. The characteristic above all affects the clarity of the liquid output which is dependent on the volumetric throughout rate, where a higher flow rate will result in a poor liquid clarity. Another characteristic that influences the clarity of the liquid output is the differential speed. A low differential speed results in a better clarity, therefore, aiding in the separation process. The Force also plays a role in the clarity of the liquid discharge. Higher force results in an increase in the separation of the solid particles from the liquid and yields a better clarity.
Decanter centrifuge in China is the 4th class solid control equipment in whole drilling mud system. The industrial decanter is used to process drilling mud discharged from desilter cones or mud cleaner. As a decanter centrifuge china factory, BZ solid control oil drilling company offers you the best decanter centrifuge at competitive price. BZLW industrial Decanter Centrifuge Features Bowl Cylindrical and the Conical section made of Duplex Stainless Steel 2205 by centrifugal casting. Other parts of the bowl assembly are made of stainless steel 316L. Screw protection: Tungsten Carbide Tiles for longer life and easier replacement. Screw flow distribution port and bowl solids discharge port protected by tungsten carbide alloy. Easy to adjust liquid discharge weir height for flexible application.
Decanter Centrifuge Features and Benefits: 1. Innovative design includes longer bowl, allowing drilling fluids to thread through more slowly, thus resulting in drier solids and finer separation point; 2. Big bowl offers big volume. It also generates high-G force; 3. Stainless steel bowl, scroll, compartment are available and covered with corrosion-proof coating so as to have longer lifespan; 4. Tungsten carbide scroll points with wide spacing flights at tapered end create a finer layer of conveyed solids for consistent, uniform separation and maximum solids control efficiency. 5. German FAG or Swedish SKF brand bearings are available; 6. Electrical Components complies with SIEMENS/Schneider ATEX or IEC Ex. 7. Screw pump and submersible slurry pump are provided to meet liquid feeding requirements of centrifuge of various customers
Oilfield Decanter Centrifuge Working Principle: Decanter Centrifuge is driven by two motors. The main motor drives the drum and the outer casing of differential through belts while the auxiliary motor, after the differential shifting speed, drives the spiral propeller. This will make the drum and the spiral propeller rotate in the same direction with a certain differential speed.
By separating the water and solids from the sewage, nightsoil, and livestock wastewater sludge as well as the sludge from a concentration and from the dewatering process, this centrfuge maintains a constant cake moisture content and recovery rate.
The Centrifuge can be used in various fields where various types and shapes of contrifuges are needed, such as in the sludge from civil engineering works and in the chemical, food processing, and steel industries.
It is used when the solids are in a poor condition because of extra sedimentation and the mixed sludge from livestock, nightsoil, andsewage treatment plants.
With a 3 phase decanter centrifuge, it is possible to separate 3 phases from each other in one process step only. For example, two liquids which cannot be mixed because of different densities (e.g. oil and water) are separated from a solids phase. The heavy liquid (water) collects in the middle between the oil and the solids layer. Thus the two liquids separated from each other can be drawn off from the decanter. The solids are transported via the scroll to the discharge openings as it happens also in 2-phase separation. Typical applications of 3-phase separation are the production of edible oils such as olive oil, oil sludge processing, the production of biodiesel .
