Oilfield Waste Treating Process
Oil Slops & Sludge treatment process:
Base on our skid-mounted and fixed sludge processing system, we’ve developed equipment especially for oilfields and refineries in remote areas with low productivity, scattered waste resources and in poor ground/environmental conditions.
To achieve the simplicity, applicability, reliability and meeting production needs, we’ve designed and manufactured the third generation mobile processing system.
The full set is made up with multiple skid-mounted modules, which can be flexibly placed according to the site conditions while working as effectively as a fixed processing plant.
- The compact mobile equipment system is comprised of several small modules, which gave it a large processing capacity. Solid or liquid oilfield sludge, aging or new oilfield sludge can be effectively separated into oil, soil and sand by the system. Water and chemical agents can be recycled and reused. The oil separated from the sludge is ready to be recovered and the sands is a good material for the production of high- strength wall bricks and paving slabs using brick molding machines.
- Components — Six Skid Modules
Skid module One: automatic solid feeding system
The dehydrated oil is then fed continuously into a vacuum distillation plant for fractionation in exactly the same fashion as crude petroleum. The fractions obtained are as follows:
- Send sludge (wet and dry) into the flotation-vibrating screen with a forklift to screen stones, steel, wood and other unwelcomed debris.
- Filtered sludge goes into the automatic metering feeder with a frequency converter to adjust shaft-less spiral screw speed to achieve automatic metering feeding.
- The feeder carries the oil sand directly into the grinding wheel sand mill. The powerful crushing force of the mill crushes the bulk oil sludge and sufficiently mix it with biological enzymes.
- Agents-adding device consists of a tank and a metering pump. There is a mixer inside the tank and several electrical heating rods at the bottom for operations in cold weather condition. The metering pump is comprised with a diaphragm pump and a frequency converter to achieve accurately metered agents mixing.
- The mixture of crushed sludge and agents then sent to skid module three through the shaftless spiral conveyor.
Skid module two: liquid feeding system
- Sludge pump pumps liquid sludge into the storage tank. The water goes back to the pool. The control valve at the bottom of the tank adjusts the liquid flow.
- Concrete piston pump in the bottom of the tank carries liquid sludge directly into skid module three.
Skid module three: level 1 cleaning device
- Flotation sifter are in vibrating structure, which screens out the debris that is greater than a screen hole, and fall into the debris bucket, and oil sands fall into the powerful stirring and cleaning device.
- Level 1 cleaning device uses a powerful horizontal stirring tank with a flotation sifter on the top. Inside are stirring wings, oil skimmers, grating plates, automatic liquid level controllers, automatic temperature controllers , stainless steel steam radiator etc.
- Oil Skimmer. In rotation, oil that adhered to the surface of the rotary turntable is brought out of the water and scraped off by the oil scraper on the top of the rotary turntable then flows into the oil trap and pumped out. Oil recovered by this skimmer has less water content (lowest to 3%).
- The liquid sludge mixture is cleaned through the horizontal mixing tank described in ②. Then the liquid is pumped into Level 2 and Level 3 cleaning devices by the Slurry Pump.
Skid module four: level 2 and 3 cleaning device
- After level 1 stirring cleaning, the sludge will be fully cleaned through level 2 and level 3 vertical cleaning devices. The recycled oil from level 1 device will go back to skid module three, and recovered by the oil skimmer.
- After cleaning, the sludge is pumped to the skid module five.
Skid module five: automatic discharge system
- Sludge fluid is pumped into vortex grit device. The water swirling vortex rapidly made sand sink to the bottom and separate from sludge liquid.
- Adjust the frequency converter based on the sand particle size. Then and will be taken out through the shaft-less spiral which reduces the water content.
- The sand is removed by a scraping machine and transported by the conveyor belt to the storage. The water is pumped back to the circulating pool.
- The sludge fluid goes into an air flotation machine; This machine will further separates water from the fluid. Oil droplets sticks to tiny water bubbles, then float on the water surface after gathering and growing into bigger bubbles. Crude oil are stored in crude oil storage pool through oil scraper. The sludge sink in the bottom of the pool and pumped into the centrifugal machine. The system removes up to 90% SS and 70% COD and BOD.
- The clean water at the top of the flotation machine flows into circulation precipitation pool.
- Soil at the bottom of flotation machine are pumped into the centrifuge. The Screw Conveyor of Decanter Centrifuge can continuously feed, separation and unload with large processing capacity and small unit power consumption. After treatment suspension liquid solid particle size is more than 0.05 mm, and the water content is quite low and transported and stored directly by conveyer belt.
Skid module six: electrical appliance control room
- Electric cabinet with frequency conversion control, easy operating on a horizontal operation console with a nice view.
- Electrical appliance control room is a steel-framed heat preservation room.
Key Words: Advanced technology, simple operation, easy installation, high treatment efficiency, high degree of automation, flexible and moveable.