A disc separator is a type of decanter centrifuge used to separate difficult-to-separate materials (eg, suspensions of viscous liquids and fine solid particles or emulsions of similarly dense liquids, etc.). The disc separator in the separator is the most widely used decanter centrifuge.

The main application areas 1. Mineral oil industry: ship host, land-use diesel engines, power stations and other fuel and lubricant purification;

2. Dairy industry: clarification and purification of fresh milk, degreasing;

3. Vegetable oil industry: purification and clarification of palm oil, degumming, soap removal, dehydration and dewaxing of vegetable oil refining;

4. Beverage products industry: clarification of beer, juice, beverages, extraction of plant proteins, wastewater treatment, etc.; clarification of bioengineering fermentation broth;

5. Starch industry: Concentration and grading of starch slurry;

6. Pharmaceutical industry: purification or clarification of extracts of antibiotics, biochemical pharmaceuticals, clarification of traditional Chinese medicines, etc.;

7. Chemical industry: purification or clarification of chemical raw materials;

8. Lanolin industry: extracting and purifying lanolin from washed hairs;

9. Latex industry: purify and concentrate natural rubber sizing;

10. Other industries: such as laboratories, petroleum, coking, kaolin, pulp recycling, electrolyte treatment, wastewater treatment, environmental protection, etc., as well as animal and plant protein extraction, animal fat extraction and refining, and separation of mixed fatty acids.

The marine disc separator is mainly used to remove the water and impurities in the fuel and lubricating oil of marine diesel engines and other equipment to reduce the wear of mechanical equipment and prolong the life of mechanical equipment. The design, manufacture and acceptance of marine disc separators are in line with the standards of GB/T 5745-2002 marine disc separators.

Principle and Structure The disc separator is a vertical centrifuge. The drum is mounted on the upper end of the vertical shaft and is driven by a motor through a transmission to rotate at a high speed. Inside the drum there is a group of disc parts that are nested together. There is a small gap between the disc and the disc. The suspension (or emulsion) is fed to the drum from a feed tube located in the center of the drum. When the suspension (or emulsion) flows through the gap between the discs, the solid particles (or droplets) settle on the disc under the action of a centrifuge to form a sludge (or liquid layer). The sediment slides along the surface of the disc and escapes from the disc and accumulates in the area with the largest diameter inside the bowl. The separated liquid exits the drum from the outlet. The role of the disc is to shorten the settling distance of the solid particles (or droplets) and enlarge the settling area of ​​the drum. Since the disc is installed in the drum, the production capacity of the separator is greatly improved. The solids accumulated in the drum are removed manually after the separator is shut down, or removed from the drum by a slag discharge mechanism without stopping the machine.

The disc separator can perform two operations: liquid-solid separation (ie separation of the bottom concentration suspension), clarification operation; liquid-liquid separation (or liquid-liquid-solid) separation (ie separation of the emulsion), Separate operation.

A stack of conical discs was installed in the operating drum, and centrifuges were used to separate the emulsion and low-concentration suspension components by centrifugal sedimentation. The disc separator can be operated under closed, high temperature, low temperature, pressure and vacuum conditions for the extraction of cream and fruit juice from milk, the purification of beer, animal and vegetable oils, transformer oils, etc., as well as yeast concentrates and plasma from animals. Extract serum and so on.

When the suspension is separated, the suspension enters the drum from the center feed tube and flows from the outer edge of the disc bundle through the gap between the discs to the inner edge of the disc. Due to centrifugal force, the solid particles settle to the inner surface of each disc while flowing with the liquid, slide to the outer edge of the disc, and finally deposit on the drum wall. The clarified liquid accumulates in the direction of the center of the drum and is discharged through an overflow or centripetal pump. When the emulsion is separated, the emulsion enters the gaps of the discs through the feed holes on the disc bundles, and is divided into heavy liquid and light liquid according to different densities. The heavy liquid flows along the inner surface of the disc toward the drum wall, and the light liquid Flows to the center and is expelled through overflow and centripetal pumps. The position of the feed hole should be at the junction of the heavy liquid layer and the light liquid layer. Here is called the neutral layer, its radius, where k is the density ratio of heavy liquid to light liquid, and R1 and R2 are the discharge radii of heavy liquid and light liquid, respectively. When the feed hole and the neutral layer do not coincide, the discharged heavy liquid or light liquid is not pure. In this case, the radius of the heavy liquid or light liquid discharge outlet can be changed to adjust the position of the neutral layer. Since the liquid in the rotating drum is divided into many thin layers by the disc bundle, separation is performed in the thin layer, and the distance of centrifugal settlement is very short, which significantly improves the separation speed. The separation factor of the disc separator is relatively high, ranging from 4,000 to 10,000. Due to the large number of discs in the drum, the settlement area is significantly enlarged, and the separation efficiency is high.

The centripetal pump has a stationary impeller fixed on the casing. The outer edge of the impeller is submerged in a separating liquid layer that rotates synchronously with the rotating drum. The separating liquid enters the arc-shaped flow path from the outer edge of the impeller and flows to the central discharge tube of the impeller. discharge. The impeller converts the kinetic energy of the rotating liquid into static pressure, and the separated liquid discharged from the rotating drum is directly conveyed to a height of 10 to 20 meters.

The slagging method manual slag disc separator is operated intermittently. It consists of a base, a transmission, a drum and a casing. The whole machine is vertical and the drum is under the support type. There are six radially arranged spring (or rubber pads) damping devices outside the main bearing of the drum. Rotary drum drive usually adopts helical gear speed-up transmission, and some adopt belt drive. The drum cover and the drum body are fastened by a thread locking ring, and the sealing ring is leakproof. The disc is conical, and its half cone angle is larger than the friction angle between the solid particles and the surface of the disc, generally 30° to 45°, the disc number is 50 to 180, and the disc gap is 0.5 to 2 mm. After the separator has been working for a period of time, the sediment on the inner wall of the drum increases, and the clarification of the separation liquid decreases. When the clarification of the separation liquid is unsatisfactory, the drum is shut down and the sediment in the drum is removed manually. This separator has a throughput of 45 m3/h and is suitable for handling suspensions and emulsions having a particle diameter of 0.001 to 0.1 mm and a solid concentration of less than 1%.

The nozzle slag disc separator operates continuously. The overall structure is similar to the artificial slag disc separator, but the inner cavity of the drum is double-tapered, which can compress the sediment and increase the sediment concentration. The inner diameter of the drum is up to 900 mm. There are 2 to 24 nozzles that spray slurry-like sediment around the periphery of the drum, and the nozzle hole diameter is 0.5 to 3.2 mm. The number of nozzles and the pore size are determined according to the nature of the suspension, the degree of concentration and the amount of treatment. The sediment flow rate through the nozzle is large, and the nozzle is made of wear resistant materials such as cemented carbide, corundum and boron carbide. In order to increase the slag discharge concentration, this separator also has a structure that recirculates the discharged sediment part to the rotary drum. The solids concentration of the sediment can be increased by 5-20 times compared to the solid concentration of the feed. This separator has a throughput of up to 300 m3/h and is suitable for handling suspensions with a solid particle diameter of 0.1 to 100 μm and a solids concentration of usually less than 10% (up to 25%).

The valve slag disc separation machine uses the ring valve to open and close the slag outlet for intermittent slagging. It is also called automatic slag disc separator. The overall structure is similar to the artificial slag disc separator. The feature is that there is a valve slag discharge device inside the drum, and the sediment in the drum can be removed without stopping. During operation, the suspension is added to the center of the drum and the separation is performed. The total pressure of the sealing water under the valve is greater than the total pressure of the suspension acting on the valve. The valve is at the top and the slag outlet is closed. When slagging is stopped, the feeding is stopped and the operating water is added to the bottom of the drum to open the sealing water pressure relief valve around the drum to discharge the sealing water. The valve is rapidly lowered by the pressure of the suspension in the rotating drum and the slag discharge port is opened. After draining the sediment and liquid in the drum, the supply of operating water is stopped, the pressure relief valve is closed, the pressure of the seal is increased, and the valve rises to close the slag discharge port to complete a work cycle.

Automatic control valve slagging methods are: 1 using time relays to control the slag discharge in accordance with the predetermined operating cycle; 2 photocell monitoring and separation liquid clarification control slagging; 3 according to the degree of drum sediment accumulation, from the pressure signal or slag surface signal Control slagging. The slag discharge time is generally 1 to 2 seconds. Part of the slagging drum can control the shorter slag discharge time, only discharge part of the sediment in the drum, and does not discharge the liquid. When the slag is discharged, it can be continuously separated without increasing the processing capacity. The maximum throughput of this separator is up to 60 m3/h. It is suitable for the treatment of solid particles with a diameter of 0.001-0.5 mm, solid-liquid density difference of more than 0.01 kg/dm 3 and solids with a concentration of less than 10%. Turbid fluid.