Continuous purification of motor oils using a three-phase separator

Patent metadata

Field	Value
Publication number	US-10696918-B2
Application number	US-201415102130-A
Country	US
Kind code	B2
Filing date	Dec 4, 2014
Priority date	Dec 10, 2013
Publication date	Jun 30, 2020
Grant date	Jun 30, 2020

Abstract

A method for continuous purification of motor lubricant oil includes circulating lubricant oil between a motor lubricant oil tank and a motor; transporting contaminated lubricant oil from the motor lubricant oil tank in a cleaning loop. The transport in the cleaning loop includes adding at least one liquid separation aid to contaminated lubricant oil; supplying contaminated lubricant oil to a three-phase centrifugal separator; continuously separating contaminants from the lubricant oil in the separator and continuously discharging a first liquid phase including purified lubricant oil from a liquid light phase outlet of the separator, continuously discharging a second liquid phase including solid contaminants from a liquid heavy phase outlet of the separator and continuously discharging a sludge phase from a sludge outlet by the aid of a conveyor screw of the three-phase separator. The method further includes transporting the first liquid phase including purified oil back to the lubricant oil tank. The present invention further provides a system for carrying out the method.

First claim

The invention claimed is:

1. A method for continuous purification of motor lubricant oil comprising:
circulating lubricant oil between a motor lubricant oil tank and a motor;
providing a pair of baffles in the lubricant oil tank to create a first portion having baffles and a second portion not having baffles;
transporting contaminated lubricant oil from said motor lubricant oil tank in a cleaning loop, said transport in said cleaning loop comprising:
supplying contaminated lubricant oil to a three-phase centrifugal separator from an inlet between a side of the lubricant oil tank and the pair of baffles;
continuously separating contaminants in the separator and continuously discharging a first liquid phase comprising purified lubricant oil from a liquid light phase outlet of the separator, continuously discharging a second liquid phase comprising solid contaminants from a liquid heavy phase outlet of the separator and continuously discharging a sludge phase from a sludge outlet by the aid of a conveyor screw of the three-phase separator; and
transporting said first liquid phase comprising purified oil back to the lubricant oil tank,

wherein the transporting contaminated lubricant oil from the motor lubricant oil tank comprises withdrawing the contaminated lubricant oil from the first portion in the lubricant oil tank, and returning oil from the separator to the second portion of the lubricant oil tank, and
wherein the circulating lubricant oil between the motor lubricant oil tank and the motor comprises withdrawing the lubricant oil from the second portion of the lubricant oil tank and returning oil through an outlet of the motor having a longitudinal axis located between the pair of baffles.

2. The method according to claim 1 , wherein at least 50% of the solid contaminants are discharged in the second liquid phase from the liquid heavy phase outlet of the separator.

3. The method according to claim 2 , further comprising adding at least one liquid separation aid to contaminated lubricant oil,
wherein the at least one liquid separation aid comprises polyhydroxy alkoxylate with a density of 1.0-1.1 g/cm 3 at 40° C.

4. The method according to claim 3 , further comprising adding at least one liquid separation aid to contaminated lubricant oil,
wherein the step of adding at least one liquid separation aid to contaminated lubricant oil further comprises mixing the contaminated lubricant oil and the liquid separation aid before supply to the three-phase centrifugal separator.

5. The method according to claim 2 , further comprising adding at least one liquid separation aid to contaminated lubricant oil,
wherein the step of adding at least one liquid separation aid to contaminated lubricant oil comprises mixing the contaminated lubricant oil and the liquid separation aid before supply to the three-phase centrifugal separator.

6. The method according to claim 1 , further comprising adding at least one liquid separation aid to contaminated lubricant oil,
wherein the adding at least one liquid separation aid to contaminated lubricant oil comprises mixing the contaminated lubricant oil and the liquid separation aid before supply to the three-phase centrifugal separator.

7. The method according to claim 1 , wherein a flow rate in the circulation of lubricant oil between the motor lubricant oil tank and the motor is more than 50 times higher than a flow rate in the cleaning loop.

8. The method according to claim 1 , wherein the first liquid phase comprising purified oil is transported back to the lubricant oil tank near said second position.

9. The method according to claim 1 , wherein the method is continuously carried out during running of the motor to which the lubricant oil tank is connected to.

10. The method according to claim 1 , further comprising measuring a concentration of at least one additive that neutralizes acid contaminants within the motor lubricant oil, and if the concentration is below a predetermined value, then adding the at least one additive that neutralizes acid contaminants to the motor lubricant oil.

11. The method according to claim 1 , further comprising filtering the oil supplied from the second portion of the lubricant oil tank to the motor with a filter.

12. The method according to claim 11 , further comprising providing a first line from the filter to the first portion of the lubricant oil tank and a second line from the filter to the motor.

13. A system for continuous purification of motor lubricant oil, said system comprising:
a lubricant oil tank, the lubricant oil tank having a first end and a second end spaced from the first end by a first distance;
a pair of baffles provided in the lubricant oil tank to create a first portion having baffles and a second portion not having baffles;
a motor;
a three-phase centrifugal separator for separating contaminants from lubricant oil, said separator comprising a rotor enclosing a separation space with a stack of separating discs, a separator inlet for contaminated lubricant oil extending into said separation space, a liquid light phase outlet for purified lubricant oil extending from said separation space, a liquid heavy phase outlet extending from said separation space, and a conveyor screw enclosed in the rotor and arranged for conveying a sludge phase towards and out of a sludge outlet of the separator;
a first line transporting contaminated lubricant oil from the first portion of the lubricant oil tank to the separator inlet and returning oil from the separator to the second portion of the tank, the first line having an inlet between a side of the lubricant oil tank and the pair of baffles; and
a second line transporting lubricant oil from the second portion of the lubricant oil tank to the motor and returning oil from the motor through an outlet of the motor having a longitudinal axis located between the pair of baffles.

14. The system according to claim 13 , wherein the motor has an effect of at least 1 MW.

15. The system according to claim 14 , wherein the motor is a two stroke engine or a four stroke engine.

16. The system according to claim 13 , further comprising a mixer for mixing a liquid separation aid to the contaminated oil upstream of the separator inlet.

17. The system according to claim 13 , further comprising a filter for filtering the oil supplied from the second portion of the lubricant oil tank to the motor, a third line from the filter to the first portion of the lubricant oil tank and a fourth line from the filter to the motor.

Assignees

• Alfa Laval Corp Ab

Inventors

• Wase Claes
• Englund Mats

Classifications

• C10M175/0058

  by filtration and centrifugation processes; apparatus therefor · CPC title

• B04B13/00

  Control arrangements specially designed for centrifuges; Program control of centrifuges (control arrangements for feed, charge or discharge B04B11/00) · CPC title

• C10M175/0091 Primary

  Treatment of oils in a continuous lubricating circuit (e.g. motor oil system) · CPC title

• C10M175/0016

  with the use of chemical agents · CPC title

• B01D21/262

  by using a centrifuge · CPC title