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US4642138A Expired / Lapsed US ⏱️ 0.0 years remaining

Method of preventing deposition of sludge in liquid tank and of removing deposited sludge

Assignee: KASHIMA ENGINEERING Co Ltd KASHIMA-GUN IBARAKI-PREF JAPAN
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Filing: 1985-03-01
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Granted: 1987-02-10
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Expires: 2005-03-01
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Abstract

Abstract In a method of preventing deposition of sludge and of removing deposited sludge, liquid spray devices installed at predetermined positions in a tank are driven by a pressure of a liquid sprayed therefrom, the liquid sprayed from the spray devices is sprayed at a predetermined speed in the tank, and the flow of the liquid removes sludge deposited in the tank.

Inventors

  • 👤 Hiroyasu Koyase
  • 👤 Kinsaku Funaki
  • 👤 Atsuo Morita

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 18:33
CPC Classifications
B; B08; B08B; B08B9/00; B08B9/08; B08B9/093; B08B9/0933; Y; Y10; Y10T; Y10T137/00; Y10T137/0318; Y10T137/0402; Y10T137/0419

Claims Analysis

Total Claims: 8
Claim 1
Independent Claim 127 words
A method of preventing deposition of sludge and removing deposited sludge within a liquid tank having a side wall surface and a bottom, said method comprising the step of spraying a liquid through a plurality of rotatable spray devices arranged at predetemined positions in said tank, wherein said sprayed liquid is of the same type as in said tank; said spray devices have spray nozzles with a downwardly inclined spraying direction; said nozzles are 0.5 to 3.0 meters above said bottom of said tank, and liquid sprayed from said spray devices has a minimum flow speed of at least 0.3 meters per second at any position inside said tank and impinges against said side wall surface at a flow speed from 0.3 to 2.4 meters per second.
Claim 2
Independent Claim 127 words
A method of preventing deposition of sludge and removing deposited sludge within a liquid tank having a side wall surface and a bottom, said method comprising the step of spraying a liquid through a plurality of rotatable spray devices arranged at predetemined positions in said tank, wherein said sprayed liquid is of the same type as in said tank; said spray devices have spray nozzles with a downwardly inclined spraying direction; said nozzles are 0.5 to 3.0 meters above said bottom of said tank, and liquid sprayed from said spray devices has a minimum flow speed of at least 0.3 meters per second at any position inside said tank and impinges against said side wall surface at a flow speed from 0.3 to 2.4 meters per second.
Claim 3
Dependent Claim 26 words
A method according to claim 1, wherein said liquid tank is a crude oil tank, and the liquid sprayed from said spray devices is crude oil.
Claim 4
Dependent Claim 33 words
A method according to claim 1, wherein said spray devices are arranged in said tank so that the distance between said bottom of said tank and said nozzles is 1.0 to 2.5 meters.
Claim 5
Dependent Claim 31 words
A method according to claim 1, wherein the minimum flow speed of liquid sprayed from said spray devices is at least 0.5 meters per second at any position inside said tank.
Claim 6
Dependent Claim 20 words
A method according to claim 1, wherein said rotatable spray devices are driven by pressure of the liquid sprayed therefrom.
Claim 7
Dependent Claim 21 words
A method according to claim 5, wherein liquid from outside said tank is sprayed through said spray devices into said tank.
Claim 8
Dependent Claim 19 words
A method according to claim 5, wherein liquid from inside said tank is internally circulated through said spray devices.

References Cited (Backward Citations)

US3874399A Cited
US3895756A Cited
US4192332A Cited
US4407678A Cited
US4426233A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1990-02-09 1990-08-11 1991-02-10 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1994-02-09 1994-08-11 1995-02-10 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1998-02-09 1998-08-11 1999-02-10 $7700.00 Window Closed / Lapsed

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