CA2053086A1 - Liquid clarifier - Google Patents

Liquid clarifier

Info

Publication number
CA2053086A1
CA2053086A1 CA 2053086 CA2053086A CA2053086A1 CA 2053086 A1 CA2053086 A1 CA 2053086A1 CA 2053086 CA2053086 CA 2053086 CA 2053086 A CA2053086 A CA 2053086A CA 2053086 A1 CA2053086 A1 CA 2053086A1
Authority
CA
Canada
Prior art keywords
tank
liquid
tube
solids
side wall
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.)
Abandoned
Application number
CA 2053086
Other languages
French (fr)
Inventor
Earl Misfeldt
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Priority to CA 2053086 priority Critical patent/CA2053086A1/en
Publication of CA2053086A1 publication Critical patent/CA2053086A1/en
Abandoned legal-status Critical Current

Links

Abstract

ABSTRACT OF THE DISCLOSURE

For the most part liquid clarifiers, i.e. apparatuses for removing suspended solids from liquids are unduly complicated in terms of structure and/or operation. A simple clarifier includes an elongated cylindrical tank with a frusto-conical bottom end, a large diameter, central downflow tube extending downwardly from the closed top end of the tank to beyond the middle of the tank for receiving a solids-containing liquid from a smaller diameter inlet tube, and for discharging the liquid against a conical deflector.
Solids settle to the bottom end of the tank for removal via an outlet pipe or for recycling via a return pipe and pump to the inlet pipe. Liquid rising in the tank overflows an annular weir or is decanted and is discharged through a second outlet pipe.

Description

20~3~86 This invention relates to a claxifier Eor separatincl suspended solids from a liquicl.
The clarifier can be used in a variety of systems, including but not limi-ted to wastewater t~eatmen-t sys-tems. In ~eneral, clarifiers for removing suspended solids from liquids -tend to be somewhat complica-ted and consequen-tly expensive to produce and maintain. Examples of pa-tented clarifiers are found in ~ni-ted States Patents Nos. 3,237,767, issued to M.J.
Fowle et al on March 1, 1CJ66; ~,64~,129 issued to P.F.
McDaniel et al on February 15, 1972; 4,357,242, issued to C.R. Chandler on Novemher ~, 1982; 4,592,845, issuecl-to P.
Lejeune et al on June 3, 19S6 and 4,663,054, issued to R.T.
O'Connell et al on May 5, 1987.

The object of the presen-t inven-tion is to ;~
15 provide a clarifier, which is relatlvely simple in -terms of -~
both structure and operation, and which is adapted to separate ~-solids from a licluid in an efficient manner. ?
Accordingly, the present incention relates to a ;~
liquid clarifier comprising tank means, said tank means ~0 including side wall means and downwardly tapering bottom wall means ~losing the bo-ttom end of the slde wall means; tube means ex-tending downwardly in said tank beyond the middle thereof; inle-t pipe means in the top wall means for introducing a solids-containing liquid into said tube means, ,`
25 said tube means being considerably larger in area than said ~

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2~3~6 inlet pipe means, whereby the velocity of liquid enterincl the tank means is substantially recl-uced upon entering sai~ tube means; deflector means in saicl-tank means beneath -the bottom end of said tube means for cleflecting -the liquicl en-tering the 5 tank -towards said side wall means and said bottom w~ll means;
first outle-t pipe means in -the ]ower end of said bottom wall means for dischargin~ solids from the tank and; second outlet.
pipe means in said side wall means promi~a-te saicl top wall means for recirculating solids from the tank means. `~
The inven-tion will be described in greater detail with reference to t~le accompanying drawings, which illustra-te a preferred embodiment of the invention, and wherein:
Figure 1 is a longitudinal seGtional view of the clarifier of Fig. l;
; 15 Figure 2 is a longitudinal sec-tional view of -the `;
clarifier of Fig. li Figure 3 is a perspective view from above of a diffuser used in the apparatus of Fic~s. l and 2, and Fi~ure ~ is a perspective view of an al-terna-tive form ~~-of deflector for use in the apparatus of Figs. 1 and 2.
With reference to Figs. l and 2, the clarifier of the present invention includes an elongated tank l, which is defined by a cylindrical side wall 2, a circular top wall 3 and a frusto-conical hottom wall S. A mi~ture of liquid and solids, i.e. a solids-containing liquid is introduced into the I
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-top end of the tank 1 via an inlet pipe 6. Fluicl is discharged from the tank 1 via an outlet pipe 7 near the top end of the tank side wall 2, and solids are discharged a-t -the narrow bottom end of the tank 1 via an outle-t pipe 9. Solids can ~e recircula-ted to the top inlet encl of the tank via a return pipe 10 connecting the frusto-conical bottom end of the tank to the pipe 6. Flow through the pipe 10 is controlled by a pump 11.
The liquid en-ters -the tank 1 via the no-t closed top end 13 of a central down flow well or tube 14r i.e~ the pipe h e~tends downwardly through the end 13 into the tube 14. Liquid ' entering the tube 14 is evenly distributed in the tube by a ;I diffuser 16. As best shown in FicJ. 3, the cliffuser L6 i~ includes a cylindrical side wall 17, and a circular bottom wall 18 containing holes 20 permitting the passage of liquid and some solids therethrough. There is sufficient clearance between the side wall 17 and the tube 14 to permit -the free .. .. .
! flow of overflow from -the diffuser downwardly in the tube 14, ~ The leng-th of the tube 14 is more than one-half the leng-th of ,~ 20 the tank 1, liquid being discharged pro~imate the junction~
'~ between the side and bottom walls 2 and 5, respectively.
a-terial discharged from the bottom end 21 of -the tube 14 is deflec-ted outwardly by a conical deflector 22. As shown in ~ig. 4, the side 24 of the deflector 2~ car be concave in the longi-tudinal direction. Alternatively, the ~, - 4 -,j .'~
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deElector can be a flat plate ~not shown) inclined wi-th respect -to the clirec-tion of flow oE the influent for deflec~-tirlg the influerlt towards one side of the tarlk 1. 'I`he deflector 22 clirects the liquicl raclially outwardly towarcls -the 5 side wall 2 and the bo-t-tom wall 5 oE the tank 1. With sufficient velocity, the liquid is deflected baek towards the center of the tank, creating a zone of radially opposed flow.
Solids settle to the bottom of the tank 1, while liquid rises until it overflows the side wall 26 of an annlllar overflow weir or tray 27 loca-ted proximate the top end of the -tank 1, or is decanted to the water-out pipe. ~s shown in Fig. 2, the weir 27 is at the same level as the fluicl ou-tlet pipe 7.
A few design considerations wor-t:hy of note are discussecl in what follows. The pipeline velocity, i.e. the flow velocity ~n the inlet pipe 6 should be equal -to or greater than the velocity required to maintain any solids in suspension and great enough to yield a flow rate ~Q):pipe diameter ratio which will result in turbulen-t flow. The type and construction of each static mi~er will have i-ts own Reynolds number indicative of when laminar flow changes to turbulent flow. The Reynolds number for pipe flow can be calculated using the equation:

Re = 3157QS
uD
when re is the Reynolds number, Q is the flow rate in g/m, '` : ' ,.,~
_ 5 -'.:

2~3~6 S is the specific gravity, u is the viscos:ity in centipoise and D is -the pipe cliameter in inches. For ]cnown values of Q, s and u, a value or ~ is selected and the Reynolds number tRe) is calculated. The Re is compared with the Re recluired for the static to achieve turblllen-t flow. :[f the vallle is unsatisfactory, a different pipe diameter D is selected and Re is again calculated.
The diame-ter oF -the cen-tral well or tube 1~ is selected using the equation ~=AV, where Q is -the flow rate in cubic feet per minu-te, A is a the cross-sec-tional area of -the tube 14 in square feet and V is the fluid veloci-ty in Eeet per minute. For a given flow rate and a selec-ted velocity, the ,~. .
- cross-sectional area and hence -the diame-ter can readily be calcula-ted. The velocity should be selectecl with goQd flow formation in mind.
The diameter of the tank 1 can also be selected using the equation Q=AV, where Q is upward flow rate in cubic feet per minute, A is the cross-sectional area of the -tank 1, and V
is the upward veloci-ty in fee-t per minute. Given Q, the upward velocity or rise rate should be equal to or less -than , , .
the particulate matter se-ttling ra-te. The settling rate is a characteristic of the influent, the specific gravity of the particula-te ma-terial and the viscosity of the liquid carrLer.
If Q is known, for a selected upward velocity V, A can be , .
~25 calculated. The cross-sectional value ~-,f A for the -tank to ~. .;
obtain the required cross-sectional area of the -tank.

~;

2~3~

In or~ler to calculate the distance between -the bot,tom end of the tube 14 and the hottom eclge of deflec-to~ 22, the first step is to calculate the surface area of cylincler formecl by ex-tencling the tube 14 downwardly to such bo-ttom edge of t,he deflector 2, and make such area equal to the cross-sectional area of the central tube 14 using -the equation 2 rh~= ~r2 , where h is less than or equal to r/2. The deflector 22 can be suspended from the tube 14 using a sleeve (not, shown). The diame-ter of -the sleeve can be greater than the diameter of -tlle tube 14, whereby eddies are formed to improve mixing.
Tt will be noted that -the followincJ descrip-tion of ~` the operation of the apparatus refers to elemen-ts or hardware - which do not form part of the invention, and which are no-t . ,~ ~ . , shown in the drawings.

In operation, a solids-containing liquic1 is fed via -the inlet pipe 6 to the tank, from a sump or other source.

Level control devices start and stop a delivery pump which is sized -to the system requirements. The pump delivers influent -through pipes, which may include one or more s-tatic mi~ers '.` ~ . .
l~ 20 t~7here chemicals, e.g. flocculants can be added to neutrali2e ', chargecd particles and to aid in flocculation.
The influent enters the -tank via the pipe 6 and the tube 14. The velocity of the liquicl en-tering the tube 14 is reduced substantially, because the diame-ter of the tube 14 is substantially greater than that of the inle-t pipe 6. Fluid .~ ~
'.

~.
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veloci-ty is inversely propc)rtional -to the s~uare of the diameter of a pipe or tube. Thus, the flow velocity in the tube 14 is substantially less than -that in the pipe 6. The long, large diame-ter central well or tube 14 maintains influent separate from clarif:ied or partially clarified effluent liquid in -the tank 1. Influent flows downwardly ou-t of the tube 14 into contact wi-th the deflector 22 which creates a cross flow, i.e. radial flow of influent towards -the side wall 2 of the casing 1 or 5. The influent hits the side wall 2 and is deflectecl back towards -the center of the tank with a downward component in -the direction of flow. Thus, a quiet or quiescen-t zone is created by radially opposed meeting and thus facilitating clarification, i.e. se-ttling of solids.
Moreover, mi~ing of the incoming liquid with liquid already in the tank l is promoted. Par-tially clarified liquid rises -to the top of the tan]c, while solids se-ttle -towards the conical ; bottom wall 5 and the outlet pipe 9. As mentioned above, liquid, with much or all of the solids removed therefrom, overflows the weir 27 or is decanted and is removed via the outlet pipe 7.
By controlling the flow velocities into and out of the tank 1, a zone of concentrated solids is maintained which, in effect, clarifies incoming liquid by contact and filtration. Because incoming solids are introduced by cross flow into an area which (e~cept during start-up) already has a ., 2~3~
concentra-tion of solids, goocl contac-t of incomincl solids with solicls alL-eacly in -the tanlc is effec-ted. The solicls conten-t of the liquid in the tank is effectecl. The solicls con-tent of the liquicl in the -tank can be incre,-secl by rec~ircuk~ting some of the solids th~ou~h the E)iE'e 10 and the pump ll. The loc~ation and shape oE the deflector 22 results in a quiescent zone 28 (Fig. 2) in the area beneath -the declector where the separation settling of solids occurs most readily.

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Claims (7)

1. A liquid clarifier comprising tank means, said tank means including side wall means and downwardly tapering bottom wall means closing the bottom end of the side wall means; tube means extending downwardly in said tank beyond the middle thereof;
inlet pipe means for introducing a solids-containing liquid into said tube means, said tube means being considerably larger in area than said inlet pipe means, whereby the velocity of liquid entering the tank means is substantially reduced upon entering said tube means; deflector means in said tank means beneath the bottom end of said tube means for deflecting the liquid entering the tank towards said side wall means and said bottom wall means; first outlet pipe means in the lower end of said bottom wall means for discharging solids from the tank and; second outlet pipe means in said side wall means for discharging liquid from the tank means.
2. A clarifier according to claim 1, including diffuser means in the top, inlet end of said tube means for reducing the velocity of liquid entering said tank means and for spreading the liquid over the area of the tube means.
3. A clarifier according to claim 2, wherein said diffuser means includes a cylindrical side wall, a circular bottom wall, and a plurality of holes in the bottom wall permitting the passage of liquid therethrough.
4. A clarifier according to claim 1, 2 or 3, wherein said deflector means includes a conical plate in said tank means beneath the bottom end of said tube means.
5. A clarifier according to claim 1, 2 or 3, wherein said side wall means is cylindrical and said bottom wall means is conical, said tube means extending downwardly to a position proximate the upper end of said bottom wall means.
6. A clarifier according to claim 1, 2 or 3, including weir means extending around the upper, inner end of said side wall means for receiving liquid rising in said tank means for discharge through said second outlet pipe means.
7. A clarifier according to claim 1, 2 or 3, including return pipe means connecting the bottom wall means to said inlet pipe means for recycling solids to the top end of the tank means.
CA 2053086 1991-10-09 1991-10-09 Liquid clarifier Abandoned CA2053086A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CA 2053086 CA2053086A1 (en) 1991-10-09 1991-10-09 Liquid clarifier

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CA 2053086 CA2053086A1 (en) 1991-10-09 1991-10-09 Liquid clarifier

Publications (1)

Publication Number Publication Date
CA2053086A1 true CA2053086A1 (en) 1993-04-10

Family

ID=4148534

Family Applications (1)

Application Number Title Priority Date Filing Date
CA 2053086 Abandoned CA2053086A1 (en) 1991-10-09 1991-10-09 Liquid clarifier

Country Status (1)

Country Link
CA (1) CA2053086A1 (en)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9207019B2 (en) 2011-04-15 2015-12-08 Fort Hills Energy L.P. Heat recovery for bitumen froth treatment plant integration with sealed closed-loop cooling circuit
US9546323B2 (en) 2011-01-27 2017-01-17 Fort Hills Energy L.P. Process for integration of paraffinic froth treatment hub and a bitumen ore mining and extraction facility
US9587176B2 (en) 2011-02-25 2017-03-07 Fort Hills Energy L.P. Process for treating high paraffin diluted bitumen
US9676684B2 (en) 2011-03-01 2017-06-13 Fort Hills Energy L.P. Process and unit for solvent recovery from solvent diluted tailings derived from bitumen froth treatment
US9791170B2 (en) 2011-03-22 2017-10-17 Fort Hills Energy L.P. Process for direct steam injection heating of oil sands slurry streams such as bitumen froth
US10041005B2 (en) 2011-03-04 2018-08-07 Fort Hills Energy L.P. Process and system for solvent addition to bitumen froth
US10226717B2 (en) 2011-04-28 2019-03-12 Fort Hills Energy L.P. Method of recovering solvent from tailings by flashing under choked flow conditions
US11261383B2 (en) 2011-05-18 2022-03-01 Fort Hills Energy L.P. Enhanced temperature control of bitumen froth treatment process

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9546323B2 (en) 2011-01-27 2017-01-17 Fort Hills Energy L.P. Process for integration of paraffinic froth treatment hub and a bitumen ore mining and extraction facility
US9587176B2 (en) 2011-02-25 2017-03-07 Fort Hills Energy L.P. Process for treating high paraffin diluted bitumen
US10125325B2 (en) 2011-02-25 2018-11-13 Fort Hills Energy L.P. Process for treating high paraffin diluted bitumen
US9676684B2 (en) 2011-03-01 2017-06-13 Fort Hills Energy L.P. Process and unit for solvent recovery from solvent diluted tailings derived from bitumen froth treatment
US10041005B2 (en) 2011-03-04 2018-08-07 Fort Hills Energy L.P. Process and system for solvent addition to bitumen froth
US10988695B2 (en) 2011-03-04 2021-04-27 Fort Hills Energy L.P. Process and system for solvent addition to bitumen froth
US9791170B2 (en) 2011-03-22 2017-10-17 Fort Hills Energy L.P. Process for direct steam injection heating of oil sands slurry streams such as bitumen froth
US9207019B2 (en) 2011-04-15 2015-12-08 Fort Hills Energy L.P. Heat recovery for bitumen froth treatment plant integration with sealed closed-loop cooling circuit
US10226717B2 (en) 2011-04-28 2019-03-12 Fort Hills Energy L.P. Method of recovering solvent from tailings by flashing under choked flow conditions
US11261383B2 (en) 2011-05-18 2022-03-01 Fort Hills Energy L.P. Enhanced temperature control of bitumen froth treatment process

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