Monthly Archives: October 2020

Selection of Sewage Treatment Agent for Decanter Centrifuge

The main function of centrifuge separator equipment is to remove insoluble matter from fluid, whether solid or liquid. This problem comes, a lot of heavy metal pollution ions are soluble, how to do this? GN discusses with you how precipitator flocculant these sewage treatment agents in the horizontal centrifuge solid-liquid separation process how to cooperate and how to choose.

The precipitator reacts to the chemical characteristics of free ions to form insoluble precipitates. The flocculant aggregates the very small solid suspended matter together to form a large particle size polymer. The pretreatment of the fluid facilitates the solid-liquid separation operation of the decanter centrifuge. Combined use of sewage treatment agents such as precipitators and flocculants, the aggregation and deposition of solid particles and the removal of some dissolved organic matter simplify the operation, save the cost, make the removal of pollutants in wastewater treatment more thorough, more efficient, more complete and lower cost.

In order to achieve a good effect of sewage treatment, the selection of chemicals in the treatment of sewage by decanter centrifuge should be specially analyzed for the physical and chemical properties of sewage, and the distribution of sewage ions, the properties of colloid and suspended matter and the concentration of selected agents should be determined. If the pollutants in water are colloidal, inorganic flocculant is the first choice to make the pollutants metastable and condensed. If the floc is small, it is necessary to add polymer flocculant or to use activated silica gel and other coagulants.

Sometimes in-depth analysis of material characteristics will bring unexpected surprises, according to the charge principle of the same sex repulsive phase absorption, The use of negatively charged flocculants to complex positive charge suspended particles with twice the result with half the effort. It is more suitable for positively charged flocculants to capture the particles with very small negative charge in sewage. Of course, to determine whether the charge properties of pollutant particles are the best partners of horizontal centrifuge, sampling and computer experiments are essential.

In the treatment of horizontal centrifuge, the choice of flocculant precipitator is best determined by sampling experiment, and the sewage sample is determined by the test centrifuge equipment, and then the best proportion of the reagent is confirmed by fine adjustment in production.

Treatment processes such as filtration and flotation are often used in wastewater treatment. By using inorganic flocculant and polyelectrolyte coagulant, the treatment capacity is greatly improved by extending the treatment range. Flocculant precipitator and other chemicals combined with the characteristics of wastewater water quality, flocculant can be used alone, or a variety of flocculant compound use or one main and one auxiliary compound use (auxiliary as coagulant aid). In many cases, the combined use of inorganic flocculant and polymer flocculant can obviously improve the coagulation effect and extend the application range of separation and processing of decanter centrifuge.

Brief Introduction of Oil Sludge Separation Equipment

What is the oil sludge separation equipment? It mainly refers to a kind of high-tech equipment which can separate solid and liquid phases in silt. Industry commonly known as lying snail centrifuge.


oil sludge separation equipment is a horizontal spiral discharge, continuous operation of settling equipment.

The working principle of this kind of separator is as follows: the drum and screw rotate at the same speed at a certain differential speed, the material is continuously introduced into the inner cylinder of the feed tube, then accelerated into the drum, and under the action of centrifugal force field, Heavy solid matter is deposited on the drum wall to form sediment layer. The solid phase deposited by the feed screw is continuously pushed to the end of the drum cone and discharged through the slag outlet. The lighter liquid phase forms an inner liquid ring, which is continuously overflowed from the overflow port of the large end of the drum and discharged from the machine through the outlet. This machine can feed, separate, wash and unload continuously at full speed. Compact structure, continuous operation, smooth operation, strong adaptability, production Large capacity, convenient maintenance and other characteristics. suitable for separating suspensions with solid-containing particle size greater than 0.005 mm, concentration range of 2-40%. Widely used in chemical, light industry, pharmaceutical, food, environmental protection and other industries.

II. Working Principles

The suspension enters the oil sludge separation equipment from the feed pipe. Under the high speed rotation of the drum, the specific gravity solid is thrown to the drum wall, and the light gravity liquid is squeezed to the center of the drum. Under the action of the differential speed of the screw and the drum, the solid deposited on the drum wall is pushed by the screw conveyer to the small end of the drum outlet, and the liquid is discharged through the large end of the drum overflow hole.

III. Selection

Choosing suitable oil sludge separation equipment can not only solve the problem of oil sludge separation and improve working efficiency, but also save production cost and reduce operating risk. The main factors affecting selection are as follows:

The speed of oil sludge separation equipment: the general oil sludge separation equipment should be above 3000 rpm, the higher the speed, the higher the separation factor of oil sludge separation equipment, the better the separation effect.

Different materials have different physical and chemical indexes, such as wear resistance, corrosion resistance and so on. The lowest material of oil sludge separation equipment abroad is 316 L, or duplex stainless steel, and ceramic synthetic material should be used for components.

Centrifuge differential control: different differential control accuracy is different, and the difference between life and maintenance cost is very large, the higher the differential accuracy, the better the adaptability to the material, so the equipment with high differential precision should be selected.

Length-diameter ratio: the larger the length-diameter ratio of oil sludge separation equipment, the greater the treatment capacity and the smaller the moisture content.

Control system: whether it is automatic programming control, at present, domestic and foreign equipment manufacturers have basically realized the automatic control of the equipment.

Installation power: affecting the control of energy consumption, general domestic equipment energy consumption ratio is high, foreign energy consumption ratio is low.

Processing technology: oil sludge separation equipment belongs to the separation equipment with high precision processing requirements. The product maintenance rate is high and the processing capacity is limited.

This is a brief introduction to the oil sludge separation equipment.

Application of Disc Centrifuge Separator

Disc centrifuge separator is a kind of settling centrifuge and a more precise branch of centrifuge equipment. It adopts centrifugal separation principle to design separation performance, which is superior to that of industrial production fluid separation. In addition, disc centrifuge can not only automatically control continuous operation, but also automatically discharge slag.

Common difficult to separate fluid materials, such as colloidal fluids consisting of viscous liquids and fine solid particles or emulsions with very small specific gravity differences, Because the specific gravity of the components in the fluid is very small or the physical characteristics of viscosity are very difficult to separate, this is the time for disc centrifuges to show off.

Disc centrifuge separators are widely used in laboratory, animal and plant protein separation, oil extraction and refining, biochemical pharmaceutical extraction and other operations. Disc centrifuge separators are commonly used in the following industries:

1. Petrochemical oil separation industry: disc centrifuge is often used for marine turbine, diesel engine, power station and other petrochemical fuel and lubricating oil separation and purification;

2. dairy separation and purification industry: disc centrifuge is often used to clarify and purify fresh milk, degreasing, cheese;

3. purification of vegetable oil industry: disc centrifuge is often used for purification and clarification of vegetable oil hair oil, degumming, soap removal, dehydration and dewaxing in vegetable oil refining;

4. beverage industry: beer, beverage, juice and other semi-finished beverage clarification, plant protein extraction, treatment of wastewater produced in production;

5. starch processing industry: starch pulp concentration and grading;

6. pharmaceutical industry: disc centrifuge is often used in biopharmaceutical antibiotics, biochemical pharmaceutical drug extraction purification and concentration, the clarification of traditional Chinese medicine extraction and purification;

7. chemical raw material manufacturing industry: disc centrifuge is often used to purify or clarify chemical raw materials;

8. lanolin industry: extraction and purification of lanolin from wool washing wastewater;

9. latex production industry: purification and concentration of natural rubber latex pulp;

10. Biofermentation: Disc centrifuges are often used to clarify bioengineered fermentation broths, concentrate, extract, liquid-solid, liquid-liquid-solid separation.

The above mentioned content is about a disc centrifuge separator performance and application scope in a simple way. if you are interested in this product, please contact us for detailed information. We have been exploring in the separation field for more than 10 years with ample experience and reference cases. We hope our products will be a great help to your project.

Introduction to Papermaking Wastewater(2)

(3) Wet cracking method

The recovery of black liquor from rice straw pulp by wet cracking method is a new technology in China. the black liquor was wet cracked at about 20 MPa,360 c for 15~30 min,. the organic matter in the black liquor was converted into gas, tar, carbon powder and organic acid, and sodium silicate was converted into Si2 precipitation at high CO2 partial pressure. Then the cracking product is separated by sedimentation method under normal pressure, and the separated liquid can be causticized to recover alkali.

(4) SCA- comparison

The basic principle of this method is similar to that of air oxidation method. The black liquid concentrated to 50~60% was separated by instant heat in the thermal decomposition furnace under the condition of insufficient oxygen. The decomposition product was Na2CO3、H2S、C.

(5) Integrated Black Liquid Utilization

Recovery of sulfate turpentine, preparation of humic acid ammonia with black liquor, recovery of tarot oil, preparation of dimethyl alum with black liquor, etc. In addition, lignin can be recovered to produce alcohol and yeast.

2. Pulping Machine Waste Water Recycling

The waste water discharged by pulp beating machine contains the same composition as black liquid, but the concentration is low. Due to the small amount of organic substances (fibers and bases, etc.) contained, it is difficult to recover, but the total solids, suspended matter and BOD5 in the wastewater are still very high, and the direct discharge is still very serious for water pollution, so it needs to be treated. and the main treatment methods include coagulation sedimentation, air floatation, activated sludge, stabilization pond, biofilter and A/O.

3. Paper Machine Wastewater Recycling

The waste water discharged from the paper machine contains a large amount of fiber, if it is not recycled, it will cause a great waste. Therefore, the waste water of the paper machine must be fully recovered and reused. These water parts can be used to dilute pulp (such as white water discharged by case Kun), partly to be used in beating engineering (water absorption tank and waste water pressed by Fu Kun), and waste water that can not be used in beating engineering should be sent to the recovery device for feed recovery.

GN has been working in the waste water treatment industry for more than a decade. We are always doing our best to meet customers’ requirements and designing the most fit product for our clients’ project. In waste water treatment, we are professional. If you have any questions, please feel free to contact our sales team.