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.

I. OVERVIEW

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.

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.

(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.

I. Sources and characteristics of papermaking wastewater

There is a lot of water in the process of paper making. It takes about 300~500 m3, to produce 1 paper. In paper wastewater, it not only contains a large number of raw materials (about 20% of raw materials are lost with wastewater), but also contains a lot of chemicals and other impurities.

For the limited treatment of papermaking wastewater. First of all, we must understand the water quality of papermaking wastewater. There are three kinds of wastewater from alkaline papermaking:

1. cooking wood pulp (or straw pulp) generated waste liquid, also known as black liquid.

2. beating machine and pulping machine discharged wastewater, called beating wastewater.

3. paper machine wastewater, which can be directly used called white water.

The main pollutants contained in these wastewater are as follows:

1. suspended

Includes collapsible and non-collapsible suspensions, mainly fibers and fine fibers (i.e. broken fiber fragments and miscellaneous cells)

2. biodegradable organic compounds

Including low molecular weight hemicellulose, methanol, acetic acid, formic acid, sugar and so on.

3. refractory organic matter

It mainly comes from lignin and macromolecular carbohydrates in fiber raw materials.

4. toxic substances

Black liquor contains rosin acid and unsaturated fatty acids and so on.

5. acid-base poisons

The ph value of alkali pulping wastewater is 9~10, and that of acid pulping wastewater is 1.2~2.0.

6. chroma

The residual lignin in pulping wastewater is highly colored.

II. Recycling of papermaking wastewater

Because papermaking wastewater consists of three kinds of wastewater: black liquid, pulping machine wastewater and papermaking machine wastewater, its recovery and utilization is mainly aimed at these three kinds of wastewater.

1. black liquor recycling

 (1) Traditional alkali recovery (combustion)

The paper industry uses a large amount of alkali, each production of 1 t pulp needs 200~400 kg caustic soda. About 35% of the black liquor discharged after cooking is inorganic, the main components of which are free NaOH、Na2S、Na2SO4 and other sodium salts combined with organic matter. The purpose of alkali recovery is to convert these sodium salts into NaOH and Na2S recycling to reduce costs and reduce pollution to water bodies.

(2) Wet oxidation

Wet air oxidation refers to the process in which organic matter in wastewater is oxidized and decomposed at high temperature and high pressure, the degree of oxidation depends on the temperature and pressure used. This method is suitable for caustic soda black liquor.

In recent years, with the rapid growth of the food industry, the waste water discharged by it greatly pollutes the environment, and loses a lot of energy and water resources, which in turn restricts its own growth. Due to the severe lack of resources in the face of the world at this stage, it is urgent to choose the appropriate waste water disposal punishment to achieve the goal of water saving and energy saving.

The important source of sewage in food industry is the process of food processing, such as punishment, washing, dehydration, filtration, dispersing and refining, deacidification, deodorization and cooking. Sewage contains a large amount of egg white, organic acids and carbohydrates. Due to the existence of many plankton, dissolved organic matter in water grows rapidly, and humus is easy to occur and accompanied by unpleasant gas. At the same time, copper, lead, manganese, chromium and other metal ions other metal ions in these sewage, and bacteria and coliform bacteria often exceed the national discharge scale.

The important pollutants in wastewater are (1) solid substances, such as vegetable leaves, pericarp, minced meat and poultry feathers, etc .;(2) oil, egg white, starch, colloid, etc .;(3) acid, alkali, salt, sugar, etc. dissolved in wastewater :(4) mud sand and other organic matter entrained by qualitative materials ;(5) pathogenic bacteria, etc. Food industry wastewater is characterized by high organic matter and suspended matter content, easy to erosion, the same usually no toxicity. Its harm is to make the water body eutrophication, so as to cause aquatic animals and fish to die, promote the accumulation of organic matter under the water odor, deterioration of water quality pollute the environment.

Since there are many kinds of food, there are many kinds of material springs, the sewage of food industry has the characteristics of suspended matter, high oil content, heavy metal ions, large COD and BOD value, large range of water quality and quantity change, high content of nitrogen and phosphorus compounds, and high water temperature in some environments. Therefore, the punishment of sewage disposal in food industry is usually to accept solid-liquid dispersion skills to remove suspended matter and drifters from sewage to reach the sewage discharge scale.

Solid-liquid dispersion skills we accept Zhejiang Sanlian environmental protection machine equipment deployment Co., Ltd. LW spiral discharge settling machine. It is important to be used in the field of solid and liquid dispersion in all living wastewater, industrial wastewater, chemical, food, pharmaceutical and similar production industries.

The process of wastewater from the food industry is as follows:

The suspension of wastewater in the food industry enters the drum through the feed pipe from the spiral outlet. Under the action of the centrifuge in which the high speed rotation takes place, the solid particles with large specific gravity are deposited on the inner wall of the drum. After dispersing the clear night through the liquid layer adjustment plate opening overflow and flow drum. The relative activity between the spiral body and the drum (that is, the differential speed) is realized by the differential, and its fineness is controlled by the auxiliary motor, thus realizing the continuous dispersion of the centrifuge to the material.

All kinds of waste water biological disposal punishment system is constantly emerging, the above-mentioned food wastewater is to accept the new solid-liquid dispersion skills, with high use rate, simple installation, wide application scope and other advantages, and has been put into practice in foreign countries, to achieve success. We can learn from the disposal and punishment skills of these ancestors, and trust that with the continuous strengthening of people’s awareness of environmental protection, the water environment of our country will certainly change.

Filter press and horizontal screw centrifuge are common solid-liquid separation equipment, the amount of retention is very large, rich sunshine and you solid-liquid separation production line machine from filter press to horizontal screw centrifuge technical advantages:

1. horizontal centrifuge without filter media,

Filter press pressure filtration of filter medium (filter) to separate solid and liquid, need to use high pressure water to avoid filter belt obstruction; horizontal centrifuge high speed rotation to produce Li Xin position to separate solid-liquid centrifugal settlement, It is not suitable for filter medium because of filter screen, which bypasses the common filter clogging problem in filter operation.

2. horizontal screw centrifuge is widely applicable

Filter press can also most of the solid-liquid separation, but the oil, viscosity and other strong adhesion of solid-liquid separation needs pretreatment and incomplete separation; horizontal screw centrifuge separation adaptability, can achieve solid-liquid two-phase separation and solid-liquid three-phase separation, better adaptability to solid-liquid separation.

3.Automation of production line of 3. horizontal screw centrifuge:

Filter press is intermittent operation of manual cutting slag, loading and unloading belong to intermittent operation most or need manual coordination is not conducive to the formation of automatic production line to improve production efficiency; Horizontal centrifuge can realize automatic loading and unloading continuous production automatic loading and unloading can form automatic production line production efficiency.

4. horizontal screw centrifuge parameters adaptive adjustment ability,

In the process of solid-liquid separation and dehydration, the belt filter is adjusted according to the working conditions, and the parameters such as speed, tension, dosage and flushing pressure often depend on the experience of the operator, which requires high operation technology.

5.Low consumption of pre-treatment material for 5. screw centrifuge

Because filter press filter medium (mainly filter net) mesh will not be very small, so filter particle size can not be too small, small particle size should also add a lot of flocculant complex to synthesize large groups to facilitate filtration, which results in the consumption of additional pretreatment materials. In horizontal centrifuge, fine sludge can also be separated from water, so the dosage of flocculant is less, saving material input and reducing production cost;

6. horizontal screw centrifuge production line environment is good:

In addition to the main filter press, the filter press also needs to add medicine and feed conveyor washing pump air compressor and other ancillary equipment, large area, the whole machine is difficult to seal, high pressure cleaning water mist and odor pollution environment, poor production line environment;

7. low maintenance requirements for horizontal centrifuge

The number of easily damaged parts in the fuselage accessories of filter press is many times that of centrifuge. Maintenance is not only labor intensity but also high cost.

It can be seen from the above comparison that the comparison of the same processing conditions with the filter press has great technical advantages, and the solid-liquid separation production line from the filter press to the horizontal screw centrifuge is the development trend.

The solid-liquid separation capacity of horizontal screw centrifuge is strong, high efficiency and high treatment capacity. It has been widely used in sewage treatment in China, which greatly reduces the cost of sewage treatment and creates huge economic value and social environmental protection value. Here are some common operational problems for Decanter centrifuge in sewage treatment, GN discuss with you.

Decanter centrifuge is not easy —— selection is important:

The equipment principle is based on the specific gravity difference of solid and liquid to accelerate the settlement of solid and liquid by applying centrifugal force field to achieve the purpose of separation. Because there may be some differences in the parameters of different fuselage components in the design of Decanter centrifuge, such as slag discharge ability and drum requirement. Since the horizontal screw centrifugation and the use of bias, since it is sewage treatment, in the selection of course, only to buy suitable for the sewage treatment process of centrifugal separator equipment can achieve twice the result with half the effort.

Disstable separation effect —— parameter adjustment are important:

Although the parameter setting habits of each manufacturer are different, in general, in order to better cope with the material change and enhance the general performance of the machine, the commonly used adjustment of the required parameters include the speed adjustment of the drum, the speed difference adjustment of the push differential, and the height of the overflow plate. For different materials, you are too lazy to adjust the parameters to make the machine more suitable. It is really difficult to imagine what kind of teasing performance the engineering mud desliming parameters will have ~ directly to the wastewater treatment of the steel plant

Disparation effect is not good —— pretreatment is important

For the next stage of solid-liquid separation of horizontal screw centrifuge to do a good pretreatment, to achieve the best separation effect;

Decanter centrifuge is easy to damage —— production operation maintenance techniques are important:

Decanter centrifuge is suitable for frequent failures, can not be wronged you, this may be due to poor material applicability, such as material slurry impurities too much, feed too fierce resulting in slag discharge is not smooth, rotary block…

However, most of the feed impurities can be added to the material pretreatment section, the discharge is not smooth can be adjusted according to the material characteristics of the push speed difference, block can always check whether there is a lack of lubricating oil or foreign body stuck in the rotating shaft, These causes of Decanter centrifuge failure can be said to have nothing to do with the operator?

I. Widespread application

1. suitable for municipal sewage, food, beverage, chemical, leather, welding materials, paper, printing and dyeing, pharmaceutical and other industries sludge.

2. suitable for dewatering high and low concentration sludge. For low concentration (2000 mg/L~) sludge dewatering, there is no need to build concentration tank, storage tank, reduce construction cost, reduce phosphorus release and anaerobic odor production.

II. Small-scale design

1. Compact design, the dehydrator contains electronic control cabinet, metering tank, flocculation mixing tank and dehydrator body.

2. space is small, easy to repair and replace; small weight, easy to carry.

III. Not easily blocked

1. has the function of self-cleaning. There is no need to clean to prevent clogging, reduce washing water consumption and reduce internal circulation burden.

2. is good at dewatering oily sludge.

 IV. Low speed operation

1. The speed of the screw shaft is about 2~3 rpm, and the power consumption is very low.

2. failure is less, noise vibration is small, operation is safe.

V. Simple operation

1. through the electronic control cabinet, with the bubble medicine machine, mud pump, dosing pump, etc., to achieve 24 hours of continuous unmanned operation.

2. daily maintenance time is short, maintenance operation is simple.

VI. Durable

1. Almost all thebody is made of stainless steel, which can prolong the service life to the maximum extent.

2. replacement parts only spiral shaft and swimming ring, long service period.

 VII. Low investment costs

1.  Various product specifications, complete series, for different processing scale, can choose the most suitable model, to avoid overuse.

•  The body is compact in design, integrated in concentration and dewatering, with auxiliary devices such as electronic control cabinet and sludge flocculation mixing tank, which has strong compatibility with supporting equipment and is easy to design.

•  Small design, easy to adapt to local conditions, can reduce the dehydrator itself space and construction costs.

•  It has the function of sludge concentration, so it does not need to concentrate and store units to reduce the overall space and construction cost of sewage treatment facilities.

•  The main body of the dehydrator has the function of self-cleaning, so it is not necessary to use a large amount of water to prevent sludge clogging.

•  Adopt low speed spiral extrusion technology, low power consumption.

•  The electronic control cabinet is equipped with automatic control device, from conveying sludge, injecting medicine liquid, concentrating and dewatering, to discharging mud cake, realizing 24 hours automatic continuous unmanned operation and reducing workers’ expenses.

3.Characteristics of oily wastewater and its treatment methods

Oily wastewater mainly comes from petroleum, petrochemical, iron and steel, coking, gas generating station, machining and other industrial sectors. Except for the relative density of heavy tar above 1.1, the relative density of oil pollutants in wastewater is less than 1. Oil usually exists in three states in wastewater. (1) Oil slick, oil droplet size greater than 100 um, easy to separate from wastewater ;(2) dispersed oil, oil droplet size between 10~100 um, suspended in water ;(3) emulsified oil, oil droplet size less than 10 um, not easy to separate from wastewater. Waste due to different industrial sectors  The concentration of oil in water varies greatly, such as wastewater produced in refining process, oil content is 150~1000 mg\L, tar content in coking wastewater is about 500~800. Therefore, the treatment of oily wastewater should first use cadmium oil tank, recovery oil slick or heavy oil, treatment efficiency is 60~80, oil content in effluent is about 100~200 mg\L; emulsified oil and dispersed oil in wastewater are difficult to treat, Therefore, to prevent or reduce the phenomenon of emulsification. One of the methods is to reduce waste during production  The emulsification of oil in water; second, in the treatment process, as far as possible to reduce the number of pumps to lift the wastewater, so as not to increase the degree of emulsification. The treatment methods are usually air floatation and demulsification.

4.Characteristics of cyanide-containing wastewater and its treatment methods

Cyanide wastewater mainly comes from electroplating, gas, coking, metallurgy, metal processing, chemical fiber, plastics, pesticides, chemical industry and other departments. Cyanide wastewater is a kind of industrial wastewater with great toxicity, which is unstable in water and easy to decompose. Inorganic cyanide and organic cyanide are local toxic substances, and human ingestion can cause acute poisoning. The lethal dose of cyanide to human body is 0.18 g, potassium cyanide is 0.12 g, the mass concentration of cyanide to fish is 0.04~0.1 mg\L. in water The main treatment measures of cyanide-containing wastewater are as follows :(1) reforming the process to reduce or eliminate the effluents of cyanide-containing wastewater, such as using cyanide-free electroplating method to eliminate electroplating Workshop industrial wastewater. (2) Wastewater with high cyanide content should be recycled, and wastewater with low cyanide content should be purified and treated before discharge. The recovery methods include acidified aeration and lye absorption, steam desorption and so on. The treatment methods include alkaline chlorination, electrooxidation, pressurized hydrolysis, biochemistry, biological iron, ferrous sulfate, air blowing hair loss and so on. The alkaline chlorination method is widely used, the ferrous sulfate method is not thorough and stable, and the air blowing method not only pollutes the atmosphere, but also fails to meet the discharge standard.

A good design scheme can not be separated from the understanding of water quality; understanding the source and characteristics of wastewater and the production process is of great help to our design scheme and selection of treatment process. We plan to collect all kinds of industrial wastewater sources, characteristics and treatment methods, hope to be used for reference and sharing industrial water treatment industry colleagues, learn from each other, together for the development of water treatment industry in China.
Industrial wastewater refers to the wastewater discharged from the industrial production process, including process water, cooling water for machinery and equipment, flue gas washing water, equipment and site washing water, etc. Because of the variety of industrial types, each industry is composed of multi-stage processes, the properties of wastewater are completely different and the composition is very complex. According to the different harm caused by wastewater to environmental pollution, it can be roughly divided into solid pollutants, organic pollutants, oil pollutants, toxic pollutants, biological pollutants, acid and alkali pollutants, aerobic pollutants, nutritional pollutants, sensory pollutants and thermal pollution.

1. Characteristics and Treatment of Acid-base Wastewater

Acid wastewater mainly comes from iron and steel plants, chemical plants, dye plants, electroplating plants and mines, which contain various harmful substances or heavy metal salts. The mass fraction of acid varies greatly, the low is less than 1 and the high is more than 10. Alkaline wastewater mainly comes from printing and dyeing factory, leather factory, paper mill, refinery and so on. Some of them contain organic bases or inorganic bases. Some of the mass fractions of alkali are higher than 5 and some are lower than 1. Acid and alkali wastewater, in addition to containing acid and alkali, often contains acid salt. Basic salts and other inorganic and organic compounds.

 Acid and alkali wastewater has a strong corrosion, need to be properly treated before discharge.
 The principle of treating acid-base wastewater is:
 (1) High-concentration acid-base wastewater should be recycled as a matter of priority. According to the requirements of water quality, quantity of water and different processes, plant or regional scheduling should be carried out for reuse as far as possible; if reuse is difficult, or if the concentration is low and the quantity of water is large, acid-base can be recovered by concentrated method.
 (2) Low-concentration acid-base wastewater, such as cleaning water from pickling tanks and rinsing water from alkali washing tanks, shall be neutralized.

For neutralization treatment, the principle of waste treatment should be considered first. For example, acid and alkali wastewater neutralize each other or use waste alkali (slag) to neutralize acid wastewater, and use waste acid to neutralize alkaline wastewater. In the absence of these conditions, neutralizers can be used.