# US 2021/0275943 A1 · Method for cleaning fuel oil for a diesel engine

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- Number: US 2021/0275943 A1
- Document ID: US20210275943A1
- Status: Published application
- Kind: A1
- Application number: 16/330,584
- Filed: 2017-08-17
- Published: 2021-09-09
- Earliest claimed: 2016-09-06
- Assignees: Alfa Laval Corporate AB
- Applicants: Alfa Laval Corporate AB
- Inventors: Mitul SAWJANI
- Web page: https://patentgrep.com/patent/US20210275943A1

## CPC

- B01D 17/12: Auxiliary equipment particularly adapted for use with liquid-separating apparatus, e.g. control circuits
- B01D 17/0217: {by centrifugal force}
- B04B 5/12: Centrifuges in which rotors other than bowls generate centrifugal effects in stationary containers
- B04B 11/02: Continuous feeding or discharging; Control arrangements therefor
- C10G 31/10: with the aid of centrifugal force
- B04B 2005/125: {the rotors comprising separating walls}
- B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28)
- B04B: CENTRIFUGES (high-speed drum mills B02C19/11; domestic spin driers D06F; analysing, measuring or monitoring physical or chemical properties of samples during centrifuging, see the relevant subclasses for these procedures, e.g. G01N)
- C10G: CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION (cracking to hydrogen or synthesis gas C01B; cracking or pyrolysis of hydrocarbon gases to individual hydrocarbons or mixtures thereof of definite or specified constitution C07C; cracking to cokes C10B); RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES

## Abstract

A method for cleaning fuel oil for a diesel engine includes providing a fuel oil to be cleaned, supplying said fuel oil to be cleaned to a centrifugal separator, and cleaning said fuel oil in the centrifugal separator to provide a clean oil phase. The method further includes measuring the viscosity of the fuel oil to be cleaned before cleaning in said centrifugal separator or the viscosity of the clean oil phase, and regulating the temperature of the fuel oil to be cleaned based on said measured viscosity.

## Claims

### Claim 1

A method for cleaning fuel oil for a diesel engine comprising the steps of:
providing a fuel oil to be cleaned;
supplying said fuel oil to be cleaned to a centrifugal separator;
cleaning said fuel oil in the centrifugal separator to provide a clean oil phase;
measuring the viscosity of the fuel oil to be cleaned before cleaning in said centrifugal separator or the viscosity of the clean oil phase, phase; and
regulating the temperature of the fuel oil to be cleaned based on said measured viscosity.

### Claim 2 (depends on 1)

The method according to claim 1, wherein the viscosity of the fuel oil to be cleaned is measured before cleaning in said centrifugal separator.

### Claim 3 (depends on 1)

The method according to claim 1, wherein the step of regulating the temperature of the fuel oil to be cleaned comprises changing the temperature so that the viscosity of the oil to be cleaned is kept below a specific maximum viscosity vmax.

### Claim 4 (depends on 3)

The method according to claim 3, wherein the specific maximum viscosity vmax is 55 cSt.

### Claim 5 (depends on 3)

The method according to claim 3, wherein the viscosity of the oil is kept at a setpoint viscosity value vset that is below said specific maximum viscosity vmax or within a specific viscosity interval that is below said specific maximum viscosity vmax.

### Claim 6 (depends on 5)

The method according to claim 5, wherein the specific viscosity interval is between 25-45 cSt.

### Claim 7 (depends on 5)

The method according to claim 5, wherein the step of regulating the temperature of the fuel oil comprises comparing the measured viscosity to the setpoint viscosity value vset and decreasing the temperature if the measured viscosity is lower than the setpoint viscosity value vset and increasing the temperature if the measured viscosity is higher than the setpoint viscosity value vset.

### Claim 8 (depends on 1)

The method according to claim 1, wherein the step of regulating the temperature comprises regulating the temperature to temperatures above 98° C.

### Claim 9 (depends on 1)

The method according to claim 1, wherein the step of regulating the temperature of the fuel oil to be cleaned comprises changing the temperature to values between a lowest temperature tlow and a maximum limit temperature tmax, wherein the lowest temperature tlow is between 95° C. and 98° C., and the maximum limit temperature tmax is above 105° C.

### Claim 10 (depends on 1)

The method according to claim 1, further comprising a step of regulating the flow rate of the fuel oil to be cleaned.

### Claim 11 (depends on 10)

The method according to claim 10, wherein the step of regulating the flow rate of the fuel oil to be cleaned depends on the workload of the engine in which the cleaned oil phase is used.

### Claim 12

A system for cleaning fuel oil for a diesel engine comprising:
a centrifugal separator for separating impurities from a fuel oil for a diesel engine and for generating a cleaned oil phase;
at least one instrument for measuring the viscosity of the fuel oil to be cleaned or the viscosity of the cleaned oil phase;
a temperature regulator configured to regulate the temperature of the fuel oil to be cleaned; and
a control unit configured for receiving information of the viscosity from said at least one instrument for measuring the viscosity and further configured for generating an output signal to the temperature regulator based on the received information of the viscosity.

### Claim 13 (depends on 12)

The system according to claim 12, further comprising a pump for regulating the flow rate of the fuel oil to be cleaned and wherein the control unit is further configured for generating an output signal to the pump for regulating the flow rate of the fuel oil to be cleaned.

### Claim 14 (depends on 13)

The system according to claim 13, wherein the system further comprises a flow meter arranged downstream of said centrifugal separator for measuring the flow rate of a cleaned oil phase, and wherein the control unit is configured to regulate the flow rate of the fuel oil to be cleaned based on information from said flow meter.

### Claim 15 (depends on 11)

The system according to claim 11, wherein the system comprises at least one instrument for measuring the viscosity of the fuel oil to be cleaned and said instrument is arranged downstream of the temperature regulator.

### Claim 16 (depends on 12)

The system according to claim 12, wherein the temperature regulator is a heater.

### Claim 17 (depends on 2)

The method according to claim 2, wherein the step of regulating the temperature of the fuel oil to be cleaned comprises changing the temperature so that the viscosity of the oil to be cleaned is kept below a specific maximum viscosity vmax.

### Claim 18 (depends on 4)

The method according to claim 4, wherein the viscosity of the oil is kept at a setpoint viscosity value vset that is below said specific maximum viscosity vmax or within a specific viscosity interval that is below said specific maximum viscosity vmax.

### Claim 19 (depends on 2)

The method according to claim 2, wherein the step of regulating the temperature comprises regulating the temperature to temperatures above 98° C.

### Claim 20 (depends on 3)

The method according to claim 3, wherein the step of regulating the temperature comprises regulating the temperature to temperatures above 98° C.