RU2389566C1 - Device to treat soil contaminated by oil and bio diesel fuel - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to treatment of soil contaminated by oil products. Proposed device comprises worms to transfer contaminated soil, heater of the latter, evacuated chambers and boxes, gas phase condenser and worm devices equipped with plasma guns. Said worm devices comprises conical worm with small depth of worm grooves and low worm blades, while plasma guns are arranged in temperature controlled space of worm device. Worm device proportioner represents a worm conveyor with vertical and horizontal components. Worm devices are pipeline-communicated with refrigerators to allow consecutive stepwise condensation of different oil products in different drain pipes.

EFFECT: improved ecology, higher efficiency and safety.

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Description

The invention relates to the petrochemical industry, as well as to environmental protection, and can be used to clean soils contaminated with oil and biodiesel.

The prior art method for cleaning soil contaminated with oil and oil products.

US Pat. No. 5,514,286 (Grosby, Thermal desorption unit, May 1996) describes a method for recovering low boiling hydrocarbons from soil that is indirectly heated by propane gas heaters (panels). The gas phase condenses upon cooling, turns into a liquid, and collects in a container. The condensate is used according to its suitability or re-subjected to appropriate treatment, for example distillation elsewhere. And the soil freed from oil, after analysis, is taken out for reclamation or the introduction of bacterial additives into it.

The device is made on two trailers, on one of which a drum 4.5 m long, 2.4 m in diameter, with a rotation frequency of 10-18 rpm is placed, and capacitors are made on the other. When heated, volatile organic compounds evaporate and then liquefy in a condenser. The condensate after cleaning on the filter is suitable for its intended use. The processing cycle for one soil load is 45 minutes.

The disadvantage of this prototype is the low capacity of the installation for cleaning the soil, the low quality of the condensate and the high energy costs per unit volume of the resulting condensate.

US Pat. No. 5,836,718 (Price, Method and apparatus for ex situ cleaning of contaminated soil, November 1998) implements the same principle of heating the soil and evaporating the low boiling fraction of contaminants. The heating agent is air passing through a pipe system.

US Pat. No. 6,143,170 (Briggs, et al., Oil recovery system, November 7, 2000) uses a perforated centrifuge basket to separate the liquid phase. The rotation of the centrifuge separates the oil from the particles sorbing it.

US Pat. No. 6,312,528 (Summerfield, et al., Removal of contaminants from materials, November 6, 2001) uses high pressure in the chambers to extract propane, butane, dimethyl ether and other hydrocarbons.

US Pat. No. 6,383,394 (Briggs, et al., Recycling process and apparatus, May 7, 2002) also uses a centrifuge that processes polymeric materials contaminated with petroleum products or solvents. Further, polymeric materials can be used for recycling.

US Pat. No. 6,840,712 (Satchwell, et al., Thermal remediation process, January 11, 2005) uses three worm conveyors, each of which provides different temperature zones. Temperature zones are defined as a zone of low temperatures, a zone of high temperatures (temperature desorption), and a pyrolysis zone. Each temperature zone is equipped with evacuation. Heating of contaminated soil can be either direct or indirect. (Prototype).

A common drawback of all of the above installations for cleaning soil from oil is the large amount of energy required to obtain a unit volume that is acceptable for ICE fuel, as well as the many operations (primary and secondary) without which acceptable fuel cannot be obtained at all. In addition, in a number of devices there is always a great danger of explosions and a big fire, even in areas designated as low temperature zones. Most of the described devices are unprofitable, economically disadvantageous. The operation of these facilities can only be justified by huge fines for causing environmental damage.

The objective of the present invention is to develop an economically viable and powerful (in terms of soil processing) device for cleaning soils from oil pollution, taking into account labor safety and fire prevention.

The technical result achieved by the invention consists of soil purified from oil and a large amount of low boiling hydrocarbons (often comprising more than 80% of the volume of the liquid phase) obtained from oil pollution.

This result is achieved by the fact that in the device for processing soil contaminated with oil and biodiesel, having screws for moving the oil-soil mixture, mixture heaters, evacuated cavities and ducts, a condenser for the gas phase, screw devices are sealed, conical with shallow grooves between with blades (auger ribs) and equipped with plasma guns, and auger feeders are designed as a worm conveyor with vertical and horizontal components for better space metering before and after dispensers, plasma guns are installed in the thermostatically controlled space of the screw device, screw devices are connected by pipelines to refrigerators made with the possibility of sequential stepwise condensation of different petroleum products in different drain pipes.

The proposed device is, in fact, a plant for processing contaminated with oil and diesel fuel soil. The device is based on a modified cone screw, which has the ability to compress the soil it is promoting and to squeeze out the liquid phase from it. Three screw devices are used in the installation, two of which are equipped with plasma guns and a system for supplying hot gases to the screw box, and one (the third in the technological chain) acts as a pusher of hot soil through two heat exchangers.

In screw devices, the bottom wall of the box is made of a perforated liquid phase for draining into a sealed cone, followed by discharge into a container. In the first two screws (with a small depth of the screw grooves and low edges of the screw), plasma guns were made for quick and intense heating of the soil, which leads to subsequent destruction (breaking of chemical bonds) of high molecular weight oil components and the formation of low-boiling hydrocarbons. The space where the plasma guns are located is hermetically isolated from the cavity of the screw device and is configured to adjust the microclimatic conditions inside it.

After the second screw device, a sealed ripper is installed with intensive evacuation of the ripper cavity and suction of the gas phase of the hydrocarbons.

The third screw device is made without a hot gas supply system and without plasma guns. It is hermetically connected to the hopper through two heat exchangers. The hopper is also made with a cultivator and a vibrating mesh, which creates opportunities for better cooling of the soil and the introduction of biological or chemical additives into it.

That is, in short terms, we have the following definition of the invention: "A device for processing soil contaminated with oil and biodiesel, having screws for moving contaminated soil, a heater for contaminated soil, vacuum cavities and ducts, a condenser for the gas phase, characterized in that the screw devices made tight, contain a cone screw with a shallow depth of the screw grooves and low auger blades and equipped with plasma guns installed in a thermostatic space w ekovogo device, wherein the metering screw type devices formed on the worm conveyor with vertical and horizontal components, and the screw devices are connected by pipelines with a refrigerator to sequentially stepwise condensation of various petroleum products in different pipes. "

The device is presented in figures 1 and 2, where figure 1 shows a modified screw device, and figure 2 presents a diagram of a device for processing oil-contaminated soil.

The screw device has a box 1, the bottom part 2 of which is perforated to drain the liquid phase. Actually the screw 3 is made conical with a narrowing of the diameter as the soil moves. The auger blades are made low (small grooves) so that the soil mass moved along the auger is not thick and warms up well in full. The internal part of the auger is hollow with the possibility of heating with hot gases or other means. The screw is mounted on an axis rotated by the motor 4. The shirt 5 of the screw (or the cavity that limits the space around the screw) is made perforated almost throughout. The jacket supporting fasteners 6 are also perforated to allow passage of the liquid phase. The bottom part of the auger box is sealed from the external environment by a cone 7 made with a crane 8 and a pipe 9 for supplying hot gas. The same pipe is made on the auger box.

In the upper part of the box is equipped with a pipe 10 for active suction (evacuation) of hot gas and the gas fraction of oil and oil products from the cavity of the box.

A thermostatically controlled (i.e., with controlled microclimatic conditions and heat-shielding walls) space 11, in which the plasma guns 12 are placed, is made on the auger jacket.

To feed the soil contaminated with oil into the screw space, a dispenser 13 is arranged having vertical and horizontal components, made as simple and relatively sealed worm conveyors (the shirt of the conveyors is almost equal to the diameter of the screw itself). The voids and spaces of the metering augers are sealed with the soil moved along them.

In the system of the plant made three screw devices and three dispensers of this type (figure 2). This is followed by a soil spreader 14 (ripper) installed at the inlet of the third sealed screw device 15, the task of which is to push the soil through the pipe 16 into the heat exchanger 17 and 18 and squeeze out the remaining liquid fraction. In the third screw device, the blades are more powerful, and the grooves between the blades are deeper.

The heat exchanger 18 is hermetically connected to the hopper 19, made with a vacuum pump and a cultivator (litter breaker), as well as a vibrating grid 20 and the shutter mechanism 21.

The vibrating grid is made with the possibility of spraying into the soil a bacteriological or other (chemical) preparation (device not shown) for further utilization of the soil and neutralization of its pollution in natural conditions.

For utilization of the gaseous phase of oil products, refrigerators 22 (A and B) are arranged, made with the possibility of sequential stepwise condensation of different oil products into different drain pipes 23.

The described device operates as follows.

Oil-contaminated soil is loaded into the funnel of the dispenser 13 (the first, leaky, dispenser, which has a message with the external environment). The dispenser feeds the soil into the first screw device to the screw 3, which moves the soil along the axis with gradual compression and extraction of the liquid phase. The perforated shirt 5 of the screw 3 passes the liquid phase into the cone 7 for accumulation.

As you move along the axis of the auger, the soil is heated with hot gases entering box 1 and cone 7 through nozzles 9, and also by plasma from plasma guns 12. Easily evaporating hydrocarbons are removed with hot gases through nozzles 10 and sent to refrigerators 22, where they condense and flow through the pipes 23 in the collection tank.

In the second screw device, the same operations are carried out in the same sequence, after which the soil is fed to the cultivator 14, and then to the screw 15, which pushes the soil through the nozzle 16 into the heat exchangers 17 and 18, and then to the second cultivator 14 located in the hopper 19.

Loosened soil falls onto the grid 20, where biological products or chemical additives are added to it to accelerate natural regeneration in natural conditions. The finished soil through the shutter device 21 is dosed into vehicles and taken to the place of use.

Literary sources

1. Crosby R. Thermal desoption unit // Pat. 5514286 (USA). Priority 10/22/1993. Published May 7, 1996.

2. U.S. Patent 6,383,394 (Briggs, et al., Recycling process and apparatus, May 7, 2002).

3. US Patent 6,840,712 (Satchwell, et al., Thermal remediation process, January 11, 2005).

4. U.S. Patent 6,312,528 (Summerfield, et al., Removal of contaminants from materials, November 6, 2001).

5. U.S. Patent 5,836,718 (Price, Method and apparatus for ex situ cleaning of contaminated soil, November 1998).

6. Inventor and Rationalizer 5 (677) for 2006

Claims (1)

A device for processing soil contaminated with oil and biodiesel, having screws for moving contaminated soil, a heater for contaminated soil, evacuated cavities and ducts, a condenser for the gas phase, characterized in that the screw devices are sealed, contain a cone screw with a small depth of screw grooves and low auger blades and equipped with plasma guns mounted in a thermostatic space of the screw device, and the screw metering devices are made according to the type worm conveyor with vertical and horizontal components, and the screw devices are connected by pipelines with a refrigerator to sequentially stepwise condensation of various petroleum products in different discharge tubes.

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