US3661778A - Wet air oxidization system for strong sludges and liquors - Google Patents
Wet air oxidization system for strong sludges and liquors Download PDFInfo
- Publication number
- US3661778A US3661778A US107393A US3661778DA US3661778A US 3661778 A US3661778 A US 3661778A US 107393 A US107393 A US 107393A US 3661778D A US3661778D A US 3661778DA US 3661778 A US3661778 A US 3661778A
- Authority
- US
- United States
- Prior art keywords
- heat exchanger
- steam
- liquor
- flash
- liquors
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 238000007254 oxidation reaction Methods 0.000 title description 3
- 238000004326 stimulated echo acquisition mode for imaging Methods 0.000 abstract description 3
- 239000007788 liquid Substances 0.000 description 9
- 238000000034 method Methods 0.000 description 7
- 239000007789 gas Substances 0.000 description 4
- 238000005260 corrosion Methods 0.000 description 3
- 230000007797 corrosion Effects 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 238000011084 recovery Methods 0.000 description 3
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 239000010802 sludge Substances 0.000 description 2
- 238000009279 wet oxidation reaction Methods 0.000 description 2
- QPILHXCDZYWYLQ-UHFFFAOYSA-N 2-nonyl-1,3-dioxolane Chemical compound CCCCCCCCCC1OCCO1 QPILHXCDZYWYLQ-UHFFFAOYSA-N 0.000 description 1
- 101000851593 Homo sapiens Separin Proteins 0.000 description 1
- 102100036750 Separin Human genes 0.000 description 1
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000010936 titanium Substances 0.000 description 1
- 229910052719 titanium Inorganic materials 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F11/00—Treatment of sludge; Devices therefor
- C02F11/06—Treatment of sludge; Devices therefor by oxidation
- C02F11/08—Wet air oxidation
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F5/00—Softening water; Preventing scale; Adding scale preventatives or scale removers to water, e.g. adding sequestering agents
- C02F5/02—Softening water by precipitation of the hardness
- C02F5/04—Softening water by precipitation of the hardness using phosphates
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F11/00—Treatment of sludge; Devices therefor
- C02F11/06—Treatment of sludge; Devices therefor by oxidation
Definitions
- Suspended solids or scale forming compounds in the oxidized liquor can cause fouling and plugging of the shell of the process heat exchanger.
- the shell of the process heat exchanger must be designed for high pressure and high temperature and for maximum corrosion resistance. This often requires the use of expensive materials, such as nickel or titanium.
- the shell side of the heat exchanger can be designed and built for lower pressures and of less expensive materials since corrosion difliculties are minimized.
- FIG. 1 is a flow diagram illustrating the invention.
- FIG. 2 is a diagrammatic showing of a form of flash tank that can be used in the system.
- raw liquor and atmospheric air enter the system at 10 proceeding at 12 to the heat exchanger 14 from which condensate may be derived as shown. From the heat exchanger the preheated liquor or sludge proceeds to the reactor which has an inlet 16.
- the intermediate pressure in the flash tank 26 depends upon the required reactor inlet temperature. For example, if the required reactor inlet temperature is centigrade, the flash steam temperature must be higher than this or about 200 centigrade, fixing the intermediate pressure and flash tank 26 at about 15 atmospheres.
- the reactor inlet temperature at 16 is easily controlled by the temperature control valve 34 which controls steam flow to the shell side of the heat exchanger 14. If the flash steam evolved is insufficient this can be made up by supplying steam from the boiler. If excess flash steam is evolved, this excess can be directed to the steam mains for general plant use.
- the quantity of flash steam can be calculated in the usual way considering the initial temperature of the oxidized liquid and the final pressure to which this liquid is reduced or flashed.
- the oxidized liquid can generally be assumed to be water, although large quantities of dissolved salts may have some effect on the temperature-pressure relationship of the vapor of this liquid.
- the flash tank is in essence a device to separate the flash steam from the remaining liquid after pressure reduction. Design of such a tank is generally known in the art. This tank could be designed, for example, to give a liquid hold up time of 3 minutes, an upward flash steam velocity of 3-4 feet per second and could be equipped with a mesh type or baffle type of entrainment removal device in the top. The tank would also be equipped with a device to control the level of the liquid in the tank. This is a conventional device indicated at 40, and connecting the interior of the tank to the outlet, as shown in FIG. 2 in dotted lines.
- liquor and air can be mixed before admission to the heat exchanger as shown and described, liquor only can be passed through the heat exchanger and air admitted after the heat exchanger if this should become desirable.
- Oxidized liquor from the flash tank can be sent directly to post treatment as at 36, 38 as shown, or can be used for additional preheating of raw liquor if desired and convenient.
- the oxidized liquor can be flashed to an even lower temperature and the resultant flash steam evolved used for heating instead of the oxidized liquor.
- a process for the wet oxidation of raw strong liquors and sludge which include introducing the raw liquor to a heat exchanger and preheating the raw liquor, introducing the preheated raw liquor to a reactor and oxidizing the raw liquor, and conducting the oxidized liquor thence to a gas separator, introducing the oxidized liquor from the separator to a flash tank, generating steam thereby, and passing the steam through a temperature control valve back to the heat exchanger while leaving the oxidized liquor from the flash tank for post treatment separately.
Abstract
RAW LIQUOR IS INTRODUCED TO A HEAT EXCHANGER AND THENCE THROUGH A TEMPERATURE CONTROL VALVE TO A REACTOR AND THENCE TO A SEPARATOR, AND A FLASH TANK IS PROVIDED WHICH RECEIVES OXIDIZED LIQUOR FROM THE SEPARATOR AT AN INTERMEDIATE PRESSURE RESULTING IN "FLASH" STEAM USED FOR PREHEATING IN THE HEAT EXCHANGER.
Description
May 9, 1972 L. A. PRADT 73 WE'I'T AIR )KKDIZATION SYSTEM FOR STRONG SLUDGES AND LIQUORS Filed Jan. 18, 1971 GASES TO ENERGY RECOVERY SEPA RATOR OXIDIZED LIQUOR TO POST TREATMENT FLASH TANK 36 26 REACTOR 32 sTEAM FROM BOILER 34 RAw LIQUOR 1O LL n. 5
HEAT EXCHANGER CONDENSATE I F I G 2 FLASH STEAM OUTLET ENTRAINMENT QVALL VE 1 STEAM INLET 40 LIQUIO I L .Ui LL 26 I LIQUID I REsERvOIR I INVENTOR LOUIS A. PRADT BY GM/F LIQUID OUTLET I ATTO NEY United States Patent Oflice 3,661,778 Patented May 9, 1972 3 Claims ABSTRACT OF THE DISCLOSURE Raw liquor is introduced to a heat exchanger and thence through a temperature control valve to a reactor and thence to a separator, and a flash tank is provided which receives oxidized liquor from the separator at an intermediate pressure resulting in flash steam used for preheating in the heat exchanger.
BACKGROUND OF THE INVENTION Wet oxidization systems designed to accomplish essentially complete oxidation of strong liquors and sludges containing a chemical oxygen demand of about 80 grams per liter or more are well known. In such a system all the necessary preheating can be accomplished by extracting heat from the oxidized liquor. Thus, the gases and steam can be used entirely for energy recovery. Such a system Will generally operate at pressures between 50 and 250 atmospheres, the preferred range being 150 to 200 atmospheres, and at maximum temperatures of about 250 to 375 centigrade, the preferred range being 300 to 320 centigrade. This type of system has been publicized as for instance in Appita, vol. 22, No. 3, the October 1969 issue of Pulp and Paper International; and attention is also directed to U.S. Pat. 2,824,058.
Disadvantages of this system are as follows:
(1) Suspended solids or scale forming compounds in the oxidized liquor can cause fouling and plugging of the shell of the process heat exchanger.
(2) The shell of the process heat exchanger must be designed for high pressure and high temperature and for maximum corrosion resistance. This often requires the use of expensive materials, such as nickel or titanium.
(3) The system has inherent control problems. For example, any change in a system variable which causes an increase in the reactor outlet temperature will raise the temperature of the oxidized liquor going to the process heat exchanger. This in turn will cause an increase in the temperature of the feed liquor to the reactor, causing a further increase in the reactor outlet temperature. Temperature control of the system is thus subject to inst-abilities.
(4) An auxiliary heat exchanger for start-up is required in addition to the process heat exchanger.
It is the general object of the present invention to provide a wet oxidation system for strong liquors and sludges operating substantially at the same or similar conditions as above outlined but in which the disadvantages enumerated and in which the following advantages are provided:
1) The shell side of the heat exchanger can be designed and built for lower pressures and of less expensive materials since corrosion difliculties are minimized.
(2) There is no fouling or scaling in the shell side of the heat exchanger.
(3) Reactor inlet temperature control is simplified.
(4) The need for a separate steam start-up heat exchanger is eliminated.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a flow diagram illustrating the invention; and
FIG. 2 is a diagrammatic showing of a form of flash tank that can be used in the system.
PREFERRED EMBODIMENT OF THE INVENTION As shown in the diagram, raw liquor and atmospheric air enter the system at 10 proceeding at 12 to the heat exchanger 14 from which condensate may be derived as shown. From the heat exchanger the preheated liquor or sludge proceeds to the reactor which has an inlet 16.
After passing through the reactor and through line 18 into separator 20, the gases are emitted as at 22 as before for energy recovery but the oxidized liquor which exits from separator 20 through bottom valve 24 to a flash tank 26, see FIG. 2, is reduced to an intermediate pressure in the approximate range of 10 to 20 atmospheres.
This evolves flash steam as a result of the pressure reduction, and this steam is used for preheating in the heat exchanger, passing from the top of the flash tank, through the valve at 28, to the heat exchanger 14. Additionally, steam from the boiler may be introduced into line 30 from the flash tank 26 to valve 28, as at 32. The valve 28 is controlled by a temperature control valve 34 controlling steam flow to the shell side of the heat ex changer.
The intermediate pressure in the flash tank 26 depends upon the required reactor inlet temperature. For example, if the required reactor inlet temperature is centigrade, the flash steam temperature must be higher than this or about 200 centigrade, fixing the intermediate pressure and flash tank 26 at about 15 atmospheres.
The reactor inlet temperature at 16 is easily controlled by the temperature control valve 34 which controls steam flow to the shell side of the heat exchanger 14. If the flash steam evolved is insufficient this can be made up by supplying steam from the boiler. If excess flash steam is evolved, this excess can be directed to the steam mains for general plant use.
The quantity of flash steam can be calculated in the usual way considering the initial temperature of the oxidized liquid and the final pressure to which this liquid is reduced or flashed. For practical purposes the oxidized liquid can generally be assumed to be water, although large quantities of dissolved salts may have some effect on the temperature-pressure relationship of the vapor of this liquid. The flash tank is in essence a device to separate the flash steam from the remaining liquid after pressure reduction. Design of such a tank is generally known in the art. This tank could be designed, for example, to give a liquid hold up time of 3 minutes, an upward flash steam velocity of 3-4 feet per second and could be equipped with a mesh type or baffle type of entrainment removal device in the top. The tank would also be equipped with a device to control the level of the liquid in the tank. This is a conventional device indicated at 40, and connecting the interior of the tank to the outlet, as shown in FIG. 2 in dotted lines.
While liquor and air can be mixed before admission to the heat exchanger as shown and described, liquor only can be passed through the heat exchanger and air admitted after the heat exchanger if this should become desirable.
Oxidized liquor from the flash tank can be sent directly to post treatment as at 36, 38 as shown, or can be used for additional preheating of raw liquor if desired and convenient. The oxidized liquor can be flashed to an even lower temperature and the resultant flash steam evolved used for heating instead of the oxidized liquor.
It is believed that it will be clear to those skilled in the art that the advantages of the invention has been accomplished and that the shell side of heat exchanger can be designed and built for lower pressures of less expensive material because corrosion difficulties are greatly minimized; and there will be no fouling or scaling in the shell side of the heat exchanger. Also the reactor inlet temperature control is greatly simplified and made more positive and the need for a separate steam start-up heat exchanger is eliminated.
I claim: 7
1. In a process for the wet oxidation of raw strong liquors and sludge'the steps which include introducing the raw liquor to a heat exchanger and preheating the raw liquor, introducing the preheated raw liquor to a reactor and oxidizing the raw liquor, and conducting the oxidized liquor thence to a gas separator, introducing the oxidized liquor from the separator to a flash tank, generating steam thereby, and passing the steam through a temperature control valve back to the heat exchanger while leaving the oxidized liquor from the flash tank for post treatment separately.
2. The process of claim 1 wherein the generated steam is at a higher flash steam temperature than the required reactor inlet temperature.
3. The process of claim 1 wherein the generated steam is at a higher flash steam temperature than the required reactor inlet temperature, being obtained by varying the pressure in the flash tank.
References Cited UNITED STATES PATENTS
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US10739371A | 1971-01-18 | 1971-01-18 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US3661778A true US3661778A (en) | 1972-05-09 |
Family
ID=22316417
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US107393A Expired - Lifetime US3661778A (en) | 1971-01-18 | 1971-01-18 | Wet air oxidization system for strong sludges and liquors |
Country Status (7)
| Country | Link |
|---|---|
| US (1) | US3661778A (en) |
| JP (1) | JPS5427669B1 (en) |
| KR (1) | KR800000032B1 (en) |
| AU (1) | AU451553B2 (en) |
| CA (1) | CA958507A (en) |
| GB (1) | GB1322881A (en) |
| ZA (1) | ZA72121B (en) |
Cited By (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3920548A (en) * | 1972-09-29 | 1975-11-18 | Barber Colman Co | Wet oxidation process for waste material |
| US4013560A (en) * | 1975-04-21 | 1977-03-22 | Sterling Drug Inc. | Energy production of wet oxidation systems |
| US4141829A (en) * | 1976-09-09 | 1979-02-27 | Bayer Aktiengesellschaft | Process for wet oxidation of organic substances |
| US4174280A (en) * | 1974-07-17 | 1979-11-13 | Sterling Drug Inc. | Oxidation process |
| US4203838A (en) * | 1976-03-13 | 1980-05-20 | Kubota Tekko Kabushiki Kaisha | Process for the treatment of sludge |
| US4229296A (en) * | 1978-08-03 | 1980-10-21 | Whirlpool Corporation | Wet oxidation system employing phase separating reactor |
| US4261836A (en) * | 1978-06-15 | 1981-04-14 | Vereinigte Kesselwerke Aktiengesellschaft | Method of and a device for a continuous conditioning of sludges |
| US4530737A (en) * | 1982-09-20 | 1985-07-23 | Ekono Oy | Method for use in recompression evaporation of a solution |
| US4767543A (en) * | 1986-11-13 | 1988-08-30 | Universite De Sherbrooke | Oxidation of wastewaters |
| US5389264A (en) * | 1993-07-12 | 1995-02-14 | Zimpro Environmental Inc. | Hydraulic energy dissipator for wet oxidation process |
| US20060191856A1 (en) * | 2005-02-28 | 2006-08-31 | 3V Green Eagle S.P.A. | Method and apparatus for wet oxidation of sludge |
| WO2010108290A1 (en) * | 2009-03-24 | 2010-09-30 | Granit Technologies S.A. | Method and device for the wet oxidation treatment of liquid waste laden with mineral matter |
| US11292738B2 (en) | 2018-07-06 | 2022-04-05 | Beyond The Dome Inc. | Supercritical oxidation of waste |
-
1971
- 1971-01-18 US US107393A patent/US3661778A/en not_active Expired - Lifetime
- 1971-12-30 CA CA131,457A patent/CA958507A/en not_active Expired
-
1972
- 1972-01-06 GB GB67472A patent/GB1322881A/en not_active Expired
- 1972-01-06 AU AU37680/72A patent/AU451553B2/en not_active Expired
- 1972-01-07 ZA ZA720121A patent/ZA72121B/en unknown
- 1972-01-13 KR KR7200041A patent/KR800000032B1/en active
- 1972-01-18 JP JP721172A patent/JPS5427669B1/ja active Pending
Cited By (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3920548A (en) * | 1972-09-29 | 1975-11-18 | Barber Colman Co | Wet oxidation process for waste material |
| US4174280A (en) * | 1974-07-17 | 1979-11-13 | Sterling Drug Inc. | Oxidation process |
| US4013560A (en) * | 1975-04-21 | 1977-03-22 | Sterling Drug Inc. | Energy production of wet oxidation systems |
| US4203838A (en) * | 1976-03-13 | 1980-05-20 | Kubota Tekko Kabushiki Kaisha | Process for the treatment of sludge |
| US4141829A (en) * | 1976-09-09 | 1979-02-27 | Bayer Aktiengesellschaft | Process for wet oxidation of organic substances |
| US4261836A (en) * | 1978-06-15 | 1981-04-14 | Vereinigte Kesselwerke Aktiengesellschaft | Method of and a device for a continuous conditioning of sludges |
| US4229296A (en) * | 1978-08-03 | 1980-10-21 | Whirlpool Corporation | Wet oxidation system employing phase separating reactor |
| US4530737A (en) * | 1982-09-20 | 1985-07-23 | Ekono Oy | Method for use in recompression evaporation of a solution |
| US4767543A (en) * | 1986-11-13 | 1988-08-30 | Universite De Sherbrooke | Oxidation of wastewaters |
| US5389264A (en) * | 1993-07-12 | 1995-02-14 | Zimpro Environmental Inc. | Hydraulic energy dissipator for wet oxidation process |
| US20060191856A1 (en) * | 2005-02-28 | 2006-08-31 | 3V Green Eagle S.P.A. | Method and apparatus for wet oxidation of sludge |
| WO2010108290A1 (en) * | 2009-03-24 | 2010-09-30 | Granit Technologies S.A. | Method and device for the wet oxidation treatment of liquid waste laden with mineral matter |
| CH700655A1 (en) * | 2009-03-24 | 2010-09-30 | Granit Technologies S A | Method and apparatus for treatment of wet oxidation liquid waste containing mineral loads. |
| US8968574B2 (en) | 2009-03-24 | 2015-03-03 | Granit Technologies S.A. | Method and device for the wet oxidation treatment of liquid waste laden with mineral matter |
| US11292738B2 (en) | 2018-07-06 | 2022-04-05 | Beyond The Dome Inc. | Supercritical oxidation of waste |
Also Published As
| Publication number | Publication date |
|---|---|
| CA958507A (en) | 1974-12-03 |
| AU3768072A (en) | 1973-07-12 |
| JPS5427669B1 (en) | 1979-09-11 |
| AU451553B2 (en) | 1974-08-08 |
| ZA72121B (en) | 1972-09-27 |
| GB1322881A (en) | 1973-07-11 |
| KR800000032B1 (en) | 1980-01-26 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| AS | Assignment |
Owner name: ZIMPRO INC.,WISCONSIN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:STERLING DRUG INC., A DE CORP.;REEL/FRAME:004337/0879 Effective date: 19841127 Owner name: ZIMPRO INC., MILITARY ROAD ROTHSCHILD, WI 54474 Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:STERLING DRUG INC., A DE CORP.;REEL/FRAME:004337/0879 Effective date: 19841127 |
|
| AS | Assignment |
Owner name: M&I MARSHALL & ILSLEY BANK Free format text: SECURITY INTEREST;ASSIGNOR:ZIMPRO INC., MILITARY ROAD, ROTHSCHILD, WI 54474, A CORP OF WI;REEL/FRAME:004370/0126 Effective date: 19850121 |
|
| AS | Assignment |
Owner name: M&I MARSHALL & ILSLEY BANK Free format text: SECURITY INTEREST;ASSIGNOR:ZIMPRO INC.;REEL/FRAME:004857/0873 Effective date: 19850117 |