CN104923554A - Continuous and fast soil-oil separation method - Google Patents

Abstract

The invention relates to a soil-oil separating technology in the field of soil treatment, and in particular relates to a continuous and fast soil-oil separation method. The continuous and fast soil-oil separation method comprises the following steps in sequence 1 oil-polluted soil enters into a spiral conveyer continuously and uniformly, and the oil-polluted soil is conveyed to a crushing section; 2 the oil-polluted soil enters into the crushing section, many curved knives are arrayed spirally in the section, and continuous cutting and crashing are conducted on the oil-polluted soil, so that the oil-polluted soil is crushed and refined rapidly; 3 the crashed materials and alkali liquor enter into a mixer together to be mixed sufficiently; 4 the mixed materials enter into a hydrocyclonethe to conduct three-phase separation, and the water acquired in the process can be returned to the mixer to be cycled and used continuously. The continuous and fast soil-oil separation method has the advantages that the advantages of being simple and easy are possessed, continuous separation can be achieved, the water can be used circularly, the time of ht oil-polluted soil exposing to the outside word is decreased, and secondary pollution caused by the pollution dispersal is decreased.

Description

A method for continuous and rapid oil-soil separation

technical field

The invention relates to a continuous and rapid separation method for realizing oil-contaminated soil.

Background technique

Oil-contaminated soil refers to soil mixed with heavy oil such as crude oil, various refined oils, and residual oil. Oil-contaminated soil is caused by various accidents, improper operation, obsolete equipment, damage, corrosion, etc. during oilfield exploitation, petroleum refining, transportation, and use, causing crude oil and refined oil to leak to the ground and deposit on the bottom of oceans, lakes, and rivers. , mixed with soil, water, etc. to form oil, soil, water, and even mixed with other pollutants such as mixture.

The composition of oil-contaminated soil is complex, generally composed of oil-in-water (o/w), water-in-oil (w/o) and suspended solids, and is a stable suspension emulsion system. Sludge soil particles are fine, in the form of flocs, the difference between oil and water density is small, the water content is generally high (between 40% and 60%), and it is fully emulsified, and the viscosity is high and it is difficult to settle. Sludge particles have poor stability, are prone to odor, pollute the air, and are extremely harmful in production and environmental protection. The above composition of oil sludge soil makes it have high viscosity and poor fluidity; the longer the accumulation time, the higher the viscosity, and the more difficult the separation of oil and soil. Due to the mixing of sand, stone and other solid substances with ground crude oil, it is extremely difficult to collect and transport them due to their high viscosity.

On April 1, 2005, the new Solid Waste Law came into effect, requiring a one-time supplementary sewage discharge fee for undisposed hazardous waste. It can be seen that the oil-contaminated soil not only seriously affects the ecological environment, but also increases the huge economic pressure on the corresponding units. Therefore, research and development of a method and equipment for efficiently treating oily soil has become an urgent task for the development of the petroleum industry.

At present, the most widely used method for treating oily sludge at home and abroad is the solid-liquid separation method, that is, through modulation-hot washing-separation. Due to the characteristics of high viscosity, easy agglomeration and unsuitable mixing of oily soil, the existing equipment is to fully mix and wash the lye, flocculant, etc. with the soil through the stirring of the reactor, and then pass it into the centrifuge for centrifugal separation. However, such separation operation is discontinuous, and only after a whole pot of oily soil is stirred and mixed can it enter the centrifuge for separation. Such a method is inefficient and difficult to meet the needs of large-scale oil-soil separation.

Contents of the invention

The purpose of the present invention is to provide a method for continuous and rapid oil-soil separation of oil-contaminated soil, which is simple and easy to operate, with large processing capacity and continuous and rapid separation.

After the soil is polluted by oil, if it is not treated in time, it will infiltrate downward and pollute the groundwater in the outside world as time goes by, and spread to the air to pollute the air. Therefore, the treatment of oil-contaminated soil requires a continuous and rapid separation process, and the modulation of alkali washing efficiency directly determines the separation speed of oil and soil. In the preparation process, the degree of crushing of oily sludge and the degree of disturbance of mixing are closely related to the speed of alkali washing. The higher the degree of fragmentation, the greater the disturbance, the faster the alkali washing and the faster the separation. Therefore, for rapid separation, it is necessary to increase the crushing and mixing speed, reduce the mixing and crushing time, and strengthen the degree of mixing disturbance under the condition of a certain reaction temperature. The present invention mainly takes the crushing and refining device and the mixer as the core, through the rotation of the rotating shaft, a plurality of curved knives on the shaft carry out continuous milling on the oily soil to make it thin, and through the mixer with twisted helical blades arranged in a staggered manner , Increase the disturbance, so that the oily soil can be fully mixed with lye and flocculants in a short time.

A method for continuous oil-soil separation, comprising the following steps in turn:

(1) The oily soil is transported by a screw conveyor.

(2) The oily soil enters the crushing device and is continuously milled and crushed by a plurality of machetes, so that the oily soil is rapidly broken and refined.

(3) The refined oily soil, lye, flocculant, etc. enter the mixer in a certain proportion for disturbance to achieve full mixing.

(4) The mixed liquid enters the separator to separate oil, soil and water, and the separated water can be returned to the mixer for recycling. The transmission device is a screw conveyor, and the crushing device is cylindrical, and the oily soil is continuously crushed and refined through the cylindrical device. Similarly, the mixer is also in the shape of a cylinder, which continuously mixes the crushed and refined muddy materials. Due to the large separation scale of the separation device, a double-cone cyclone is used for three-phase separation.

This method has the following advantages over traditional stirring and mixing mechanical separation.

(1) Oily soil moves continuously in one direction in the equipment to realize continuous crushing, mixing and separation, which greatly improves production efficiency.

(2) Multiple scimitars cut and pulverize the oily soil multiple times, which strengthens the crushing and refining effect, shortens the crushing time, and speeds up the crushing and refining speed.

(3) The twisted helical blade makes the mixing have a higher disturbance, which improves the mixing and washing efficiency and reduces the mixing and washing time.

(4) The water separated by the cyclone can be returned to the mixer for recycling.

Description of drawings

Fig. 1 is a process flow diagram of the present invention

Figure 2 is a schematic diagram of the transmission crushing device

in the picture

1. Flow control valve 2. Oily soil inlet 3. Transmission crushing device 4. Alkali inlet 5. Pressure control valve 6. Mixer 7. Three-phase separation cyclone 8. Soil outlet 9. Oil outlet 10. Water outlet 11. Spiral transmission piece 12. Broken machete

Detailed ways

(1) The oily soil excavated from the surface passes through the flow control valve 1 and enters the transmission crushing and refining device through the inlet 2.

(2) Transmission at the 3 parts of the crushing device enables the oily soil to be cut and refined multiple times under the action of the machete, and the oily soil is crushed and refined before entering the mixer 6 .

(3) The flow control valve 1 controls the amount of lye entering, so that the two phases are disturbed and mixed in the mixer 6 .

(4) The pressure control valve 5 controls the inlet pressure of the three-phase separation cyclone 7 so that the mixed phase is separated into three phases in the cyclone 7 . The soil particles are released from the soil outlet 8. Wherein water enters mixer from water outlet 10 through lye inlet 4 and continues to circulate.

Claims (5)

1. A continuous and rapid oil-soil separation device comprises the following steps successively: (1) The oily soil enters the screw conveyor continuously and evenly, and transports the oily soil to the crushing section. (2) The oily soil enters the crushing section, where the oily soil is continuously cut and broken by many machetes, so that the oily soil is quickly broken and refined. (3) The crushed material and lye enter the mixer together for thorough mixing. (4) The water obtained from the mixed material entering the cyclone for three-phase separation can be returned to the mixer to continue to be recycled. 2. The method according to claim 1, characterized in that, the transmission in the step (1) uses spiral transmission. 3. The method according to claim 1, characterized in that, in the step (2), crushing is continuously crushed with a plurality of knives. 4. The method according to claim 1, characterized in that, the mixing device used for mixing in the step (3) is a mixer. 5. The method according to claim 1, characterized in that, in the step (4), the separator is a cyclone.