AU615532B2 - A cyclone separator system - Google Patents

Description

Davies Collison, Melbourne and Canberra.

CONKOMW HALT H OF AUSTRALIA PATENT ACT 1952 COMPLETE SPECI FICATION 615532

(ORIGINAL)

FOR OFFICE USE.

CLASS INT. CLASS Application Number: Lodged: Complete Specification Lodged: Accepted: Published: Priority: Related Art-: 9 '9 9 0*

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SECTION 34(4)(a) DIRECTI(ON SEE FO)I- D,_ NAME OF APPLICAN N AME DI RECTED Con:oCo gQc.iriH i.4, f.L C2 ADDRESS OF APPLICANT: ha1bW- h-rr-en ,sssf-s.

i-n--h eS ttaf -V-jjd,--om wa1 NAME(S) OF INVENTOR(S) Noel Carroll DAVIES CoLLISON, Patent Attorneys 1 Little Collins Street, Melbourne, 3000.

ADDRESS FOR SERVICE: COMPLETE SPECIFICATION FOR THE INVENTION ENTITLED: IMPRVED UTLET FOR CYCLONE SEPARATORS- The following' statement is a full description of this invention* including the best method of perfotaing it known to me

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-2- 13 14 15 16 17 18 19 21 22 23 o, 24 25 26 27 28 29 29 31 32 33 34 36 37 x-<(r>\38 This invention relates to a cyclone separator sy s em United States Patent 4,237,006 (Coleman et al) describes a cyclone separator having a separating chamber having first, second and third contiguous cylindrical portions arranged in that order, the first cylindrical portion being of greater diameter than the second cylindrical portion and the third cylindrical portion being of lesser diameter than the second cylindrical portion, the first cylindrical portion having an overflow outlet at the end thereof opposite to said second cylindrical portion and a tangentially directed feed inlet, the separator being adapted to separate liquids one from the other in a mixture when infed into said separating chamber via said feed inlet, one said liquid emerging from said overflow outlet and the other passing through said third cylindrical portion in the direction away from said second cylindrical portion to emerge from an underflow outlet of the separator at the end of said separating chamber remote from said first cylindrical portion 890510.cadat.051.carroll.1.2 i i The above separator Is Intended specificeally. but not exclusively, for separating oil from water* the oil In use emerging from the overflow outlet and the water from said third cylindrical portion.

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The aforementioned cylindrical portions may not be truly cylindrical# In the sense that they do not need In all cases to present a side surface which is linear In or'ous-section and parallel to the axis thereof.

For example, United States Patent 4,237,006 describes arrangements wherein the first cylindrical portion has a frustoconical section adjacent the second cylindrical portion and which provides a taper between the largest diameter of the first cylindrical portion and the diameter of the second cylindrical portion i s where this ieets the first cylihdrical portion.

Likewise, the aforementioned patent specification describes arrangements wherein a similar section of *;frustoconical form is provided to cause a tapering In *'.the diazater of the second cylindrical portion from a largest diameter of the second cylindrical portion to the diameter of the third cylindrical portion. there *V to *i also described an arrangement wherein the second cylindrical portion exhibits a constant taper over its whole length.

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0 6 -4- According to the present invention there is provided a cyclone separator system comprising elements designed, sized and arranged for treating a mixture for separating oil and water components of a liquid mixture wherein one component of such mixture is in the form of droplets in the other component and wherein said separator has a separating chamber with first, second and third contiguous portions arranged in that order, the first portion being of greater diameter than the second portion and the third portion being of lesser diameter than the second portion, the second portion being of a length which is at least ten times its diameter adjacent the first portion, the first portion having an overflow outlet at the end thereof opposite to said second portion and at least one tangentially directed feed inlet and there being an underflow outlet at the end of said separating chamber remote from said first portion, wherein the separator is adapted to separate the oil and water components in a mixture when infed into said separating chamber via said feed inlet, one said liquid component emerging from said overflow outlet and the other 15 liquid component passing through said third portion in a direction away from said second portion to emerge from said underflow outlet of the separator; and means, in use, entraining an emulsion breaker material into the liquid mixture to be separated, prior to feeding the mixture to the separator.

The present invention also provides a method of operating a cyclone separation system for separating oil and water components of a liquid mixture wherein one component of the mixture is in the form of droplets in the other component and including a cyclone separator having a separation chamber with first, second and third contiguous portions arranged in that order, the first portion being of greater diameter than the second portion and the third portion being of lesser diameter than the second portion, the first portion having an overflow outlet at the end thereof opposite to said second portion and at least one tangentially directed feed inlet and there being an underflow outlet at the end of said separating chamber remote from said first portion; the hydrocyclone separator being adapted to separate the oil and water components of the mixture when the mixture is infed into the separating chamber via said feed inlet, one liquid component emerging from said overflow 910724,dbwsM.019,auiI1.Mc,4 LC -T -I r 1 i i I i i I~ ~i-jrilr outlet and the other liquid component passing through said third portion in direction away from said second portion to emerge from said underflow outlet; wherein the method is characterised by adding an emulsion breaker material to the liquid mixture upstream of the feed inlet prior to feeding the mixture to the separating chamber.

In accordance with the present invention there is also provided a cyclone separator system comprising elements designed, sized and arranged for treating a mixture for separating oil and water components of a liquid mixture wherein one component of 10 such mixture is in the form of droplets in the other component and wherein said separator has a separating chamber having an overflow outlet at one end thereof, at least one tangentially directed feed inlet near said one end and an underflow outlet at the other end of said separating chamber opposite said first portion, wherein the separator is adapted to separate the oil and water components in a mixture when fed into said separating chamber via said feed inlet, one said liquid component emerging from said overflow outlet and the other liquid component passing through said separating chamber to emerge from said underflow outlet of the separator; and eo e f\r means arranged to- ntrain an emulsion breaker material into the mixture to be separated, prior to feeding the mixture to the separator.

The present invention further provides a method of operating a cyclone separator to Sseparate oil and water components of an oil/water mixture wherein an emulsion breaker material is added to the oil/water mixture to be separated, prior to feeding the mixture to the separator.

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-6- The invention may be applied to a cyclone separator comprising elements designed, sized and arranged for treating a mixture for separating a more dense liquid component from a less dense liquid component thereof, said separator having a separating chamber with first, second and third contiguous cylindrical portions arranged in that order, the first cylindrical portion being of greater diameter than the second cylindrical portion and the third cylindrical portion being ol lesser diameter than the second cylindrical portion, the second cylindrical portion being of a length which is at least ten times its diameter adjacent the first cylindrical portion, the first cylindrical portion having an overflow outlet at the end thereof 4 10 opposite to said second cylindrical portion and at least one tangentially directed rlOO feed inlet and an underflow outlet at the end of said separating chamber remote q from said first cylindrical portion; wherein said overflow outlet has a diameter d.

oadjacent the separating chamber, in the range 0.0035 1 where d, is the Sdiameter of the first cylindrical portion, said overflow outlet presenting a stepped Ie* 15 bore with a first bore portion adjacent the first cylindrical portion being of greater diameter than a second bore portion thereof further from the first cylindrical portion wherein said stepped bore is characterised by the provision of a pti*. passageway extending side ways from the said first bore portion to the exterior of 1° the separator, and including valve means selectively operablb to permit flow from said passageway, said passageway facilitating clearing of blockages in the overflow outlet by supply of high pressure fluid therethrough.

°°ooo o 0 In the specification of Australian Application 12421/83 various modifications of cyclone separators of the above kind are described, and these modifications may be incorporated into separators formed in accordance with this invention.

In United States Patent 4,237,006, the described cyclone separator is said to comply with a number of dimensional restrictions insofar as the relative proportions of various components thereof are concerned. These constraints are: 9011 12dbwspfl19,ou et1 .K 6 t 1 6a 0./d 2 0.04 s 4A, Ind 2 0.10 0.1 d o 2 0.25 d d, d 2 d wherein d o is the internal diameter of said overflow outlet, d, is the diameter of the first portion, d 2 is the diameter of the second portion and d 3 is the diameter of the third portion, £2 is the length of the second portion, A, is the total cross-sectional area of all the feed inlets measured at the points of entry into the separating 5 chamber normal to the inlet flow.

I It has been found that, generally speaking, the dimensional constraints therein ,mentioned are applicable with advantage to cyclone separators constructed in accordance with this invention except that is has not been found necessary to S 10 comply with the constraint concerning the ratio of the overflow outlet diameter to the diameter of the second cylindrical portion, nor necessary to adhere to the Imaximum limit of 25 for the ratio 2 /d 2 since greater values of this ratio may be employed.

0* 15 Again, in the arrangement of the United States patent specification 4,237,006, there are two feed inlets but it has not been found necessary to adhere to this.

I Arrangements with one inlet or with more than two inlets are workable.

I V 0 0 S\ 90111Zdbvpc.019,ou0cll.sp,S r *j The invention is fur~ther described by way of example only with reference to the accom~panying drawing ini whicho Figure 1 is a cutaway perspective view of a cyclone separator construuted in accordance with the presAent invention; Figure 2 is an enlarged axial cross-sectional view of the overflow outlet of the separator of Figure 1; and Figure 3 is an enlarged fragmentary cross-sectional view of the overflow outlet of the separator of Figure Th seaa000sow nPgr hsasprtn cyhon separatr swnine inr 1tha afo epaating Uanter 25te an first0, chn adtirdclidricalf porthions 12, 14eb ancooaxityrned in sntha 15 orer.iato the o yinrica partieros aregeert l sailarlo the frrsondindficatl secton andha thir cylidri porti26,28nssofate serawt haeo then ,arcyclene tseparator ndescribed int the f yeeninda porUnied States petiv 4,237,006, tdicoures ofhc knl feed pipe tu26 8 eyaeue3 associated hrwth hs big pipe 26, is visible in the drawing. The two feed S J Inlet apertures are diametrically arranged one relative to the other and positioned close to the end of portion 12 remote fromu portion 14. The end of portion 12 remote from "-ortion 14 also has a circular outlet opening 32 which leads to an overflow outlet pipe 34.

A tapered part 12a of the separating chamber is positioned between the first and second portions 12, 14 towards the second cylindrical portion 14. As expliained in United States Patent 4,237,006 however, such te ;ered section is not essential.

The second cylindrical portion 14 exhibits a taper over its length, tapering from a diameter at the end adjacent part 12a equal to the diameter of part 12a at the junction between the two portions to a somewhat lesser dimension at its opposite end. Cylindrical *:portion 16 is a constant diameter equal to the minimur.

*diameter of portion 14.

In the drawing, the length I~ of portion 12, its diameter the taper angle a of the tapered part 12a, the internal diameter d 0 of the outlet pipe 34 at its greatest diameter end, the length and diameter 12, d 2 of the second portion 14, the taper angle 0 of the second portion 14 and the lenqth 1 3 and diameter d 3 of the third cylindrical portion, as 2. ~well as the total araa A, of the two feed inlet apertures 30 may all be selected in accordance with the parameters mentioned in United States patent -9 1 4,237,006 although the outlet diameter do need not 2 constrained to be within limits as described~ therein, nor 3 need the length fZ be selected to not exceed the maximum 4 limit of 25 for the ratio 51~2 d 2 6 As described in my copending application 12421/83, a portion 7 may be added to the separating chamber 25, this portion 8 being designated by reference numeral 18 in the figure.

9 Portion 18 has a part 18a adjacent portion 16 which is of frustoconical configuration, tapering from a maximum 11 diameter equal to d 3 at its end closest to and adjoining to e12 the outlet end of cylindrical portion 16, to a diameter d 4 13 at its outlet end. At the outlet end of part 18a, fourth *14 portion 18 includes an outlet pipe 18b which is of internal 15 diameter d 4 this leading to an underflow outlet 23.

sees 16 so a* 17 Preferably, the angle y, being the conicity or half-angle of *18 the frustoconical surface of part 18a is about 450, although {19 angles in the range 300 to 600 are generally satisfactory.

In any event, it is preferred that the ratio d 4 /d 3 be in the 21 range 1:3 to 2:3. The length of part 18a is not critical to 22 the invention and in any event is normally fixed by the S. 23 selection of the aforementioned ratio of diameters d 4 to d 3 24 Likewise, the length of the pipe 18b has not been found to be important to the operation of the invention.

26 27 28 29 31 32 33 34,.

36 37 38 890510. codat. 051,carroll .1.9 r 10 1 Although part 18a is shown as having a truly frustoconical 2 cross-sectional form (that is to say it is shown as having a 3 side surface which exhibits a linear sloping configuration 4 relative to the axis of the portion when viewed in section) this is not essential. The part 18 may have a conicity 6 angle which varies along the length thereof such as either 7 increasing or decreasing the direction from the greater 8 diameter end to the lesser diameter end thereof. In any 9 event, it is preferred that the length of the part 18 be roughly the same as the maximum diameter thereof.

11 12 In use, liquid to be separated is admitted tangentially to 13 the interior of cylindrical portion 12 via feed pipes 26, 14 28, the denser component of the liquid then travelling 15 lengthwise through the separator to emerge from outlet 23 of 16 pipe 18b, whilst the lighter component emerges from pipe 34.

17 18 In practical arrangements constructed in accordance with the 19 invention, the portions 12, 14, and 16 may for example be of lengths 11 116mm, 12 1250mm, and 13 approximately 21 1000mm. The tapered part 12a may be of length about 160mm.

22 The first, second and third cylindrical portions may also in 23 such a case have diameters as follows: I 24 first cylindrical portion, diameter dl, 116mm, second cylindrical portion 14; diameter 58mm at diameter d 2 26 tapering to 27mm at diameter d 3 cylindrical portion 16, Vt 27 diameter d 3 27mm.

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37 38 890510,c-dat.051,carroll. 1,10 The 'food inlets 30 may have diameters of 20ovi with the pipe has a steppcd interior bore leading from o'itlet porton 41 djacnt utlt 32of iamt~requal to the diameter of outlet 32 and a second portion 34" away from outlet 32 of lesser diameter than bore portion 34'. Bore portion 34' may be of diameter d the range 0.125 to 0.625 preferably 0.17 to 0.47 times the diameter di of portion 12 of the separating ;:3chasr 5 Bore:porin 30yb of diam eter.Siu a dis 25.However, in principle, the' f irst bore portion may haeadiameter do anywhere in the range 0.0035 ae< The engt of he bre prtio 34"is n tiportant, I hasbeen determined that the efficiency tends to decrease slightly as the length L, of the bore portion 31is increased. With increasing length L. a point ieventually reached where the operation of the cyclone becomes unstable. it has also been found that the smaller the diameter d the larger can. be the length Lbefore unstable operation occurs. Generally the ratio L/d 0 may be up to 10 at least for ratios do/d 2 >,0.31.

12 Exam~ple Tests were conducted on a separator having diameters d 2 do, d 5 as follows: d 116mm d 2 d 18mm d 5 3.2mnm w~s operated to separate oil from a mixture with water. The length L of outlet pipe at its larger 10 diameter portion was varied and' the separating *.efficiency E measured for each variation. Separate tests were undertaken when the separator was operated 0 00 with a split ratio F equal to 1.5% and equal to .0 The split ratio F, is defined as the ratio L 1SF Volume of removed oil from outlet pipe 34 15 0 0 Volume of mixture supplied to the separator o 0 per unit time :00 The efficiency was determined by measuring the concentration C 1 of oil in the inlet mixture and the concentration of oil C 2 in the wate~r deliverod from I\ 20 the underflow outlet of the separator so that efficiency E is defined as the ratio 2< 3 4 These tests undertaken at volumetric flow of 200 L/minute gave results as shown in tables 1 and 2, where M is the 6 ratio L/d 0 7 8 Table 1 9 F 11 12 M C 1

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gos 13 PPM PPM *00 14 15 3.5 200 16 921% 16 3.5 400 22 94% 17 9.6 350 17 *18 9.6 500 30 94% 19 10.8 200 22 89% 21 Table 2 22 323 F a a 9. 24 M C 1

C

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26 PPM PPM 27 28 3.5 200 18 91% 29 3.5 400 24 94-% 9.6 400 44 89% 31 32 33 34 36 37 38 890510,c-sdat.051 .carroll .1.13 NT0) -1-

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j 14 1 2 3 4 6 7 8 9 11 12 13 14 15

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17 18 19 a e 21 22 23 24 26 S27 28 29 31 32 33 34 36 37 38 In the embodiment shown in figure 3, outlet pipe 34 also has a passageway 51 formed through the side wall thereof and providing communication between the bore portion 34' and the exterior of the outlet pipe 34. This passageway may for example have a diameter in the range 0.05 to 0.10 of the diameter dl. Passageway 51 provides communication, via an exterior pipe 55 to a valve 53. Under normal operating conditions, valve 53 may be closed so that overflow passes from the outlet 32 through the bore portion 34' and thence through the bore portion 34". However, under the condition where blockage of the pipe 34 occurs liquid may be admitted into the bore portion 34' via the pipe 55 and passageway 51 by connecting the outlet of the valve 53 to suitable high pressure liquid supply to permit liquid flow back through the pascageway 34' through the outlet 32 and into the separating chamber of the separator. This has been found to facilitate clearing of blockages, even where the blockage occurs in the bore portion 34". The supply of high pressure liquid may be the supply of liquid to be separated which may, for example, be temporarily diverted from inflow into the inlet pipes 26, 28 during the time of admission of the liquid through the passageway 51 into the outlet pipe 34.

It is possible, in an alternative embodiment of the invention (not shown), to provide 890510,c-dat.051.carroll.1.14 II 15 15 1 flow sensing means operable to sense the flow from the 2 outlet pipe 34 and to automatically operate the valve 53 to 3 divert the incoming liquid flow which is normally passed to 4 the inlet pipes 26, 28 to flow through passageway 51 to the bore portion 34' for blockage clearing.

6 7 It has been found that whilst, in general, the provision of 8 the narrow bore portion 34" provides very satisfactory 9 separation, it is necessary or desirable under some conditions to have a wider outlet from the separator than is 11 provided by the bore portion 34". Under this condition, I 12 then, it is possible to open the valve 53 whereby outflow of 13 the desired separated component through the pipe 34 occurs 14 through the passageway 51, pipe 55 and valve 53. Such an 15 arrangement is desirable, when separating oil and water from 00. 16 an oil-water mixture where the quantity of oil in the 17 mixture to be separated is relatively great. In particular, 18 it is possible to provide means for continuously monitoring i I19 the oil content of water being admitted to the inlet pipes 26, 28 and connected to operate the valve 53 so as to 21 permit outflow from the passageway 51 and pipe 55 and valve S* 22 53 under the circumstance where detected oil content exceeds 23 a predetermined value, such as one-half percent.

24 An experimental separator constructed in accordance with 26 this invention was found to perform satisfactorily for 27 separating oil and water where the separator had the 28 following dimensions: 29 31 32 33 rk' 34.

36 37 38 89051a.c sdat.05.carroll. 1.1 16- 1 diameter do of the outlet bore portion 34' 19mm 2 diameter d 5 of the outlet bore portion 34" 3mm 3 diameter d 6 of the passageway 51 9mm 4 diameter dl 116mm 6 The invention is not confined to arrangements where there is 7 a single passageway 51. For example two or more such 8 passageways of various diameters may be provided. These may 9 be selectively operable in accordance with the measured oil content or, for example, one may be used for diverting 11 outflow under the high oil content condition and another 12 used for clearance of blockages.

13 14 Operation of the separator of the invention, particularly 15 oil and water, may be facilitated by arranging for o 16 entrainment of a suitable emulsion breaker into the incoming S. 17 water-oil mixture. The entrainment may be effected by use S* 18 of known dosing techniques such as injecting an emulsion 19 breaker into the incoming liquid prior to feeding to the feed pipes 26, 28.

21 S 22 Commercially available emulsion breakers have been found 23 quite satisfactory. The emulsion breaker "Nalco 7723" 24 marketed by Catoleum Pty.Ltd. Botany N.S.W. Australia was found effective when injected in concentrations in the range 26 5 to 8 p.p.m.

S27 S 28 These and many modifications may be made without departing a 0 29 from the spirit and scope of the invention as defined in the appended claims.

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Claims (4)

1. A cyclone separator system comprising elements designed, sized and ur arranged for treating a mixture for separating oil and water components of a liquid Pc mixture wherein one component of such mixture is in the form of droplets in the 5 cc other component and wherein said separator has a separating chamber with first, second and third contiguous portions arranged in that order, the first portion being th of greater diameter than the second portion and the third portion being of lesser fr 9 diameter than the second portion, the second portion being of a length which is at m 10 least ten times its diameter adjacent the first portion, the first portion having an 10 m l overflow outlet at the end thereof opposite to said second portion and at least one cb tangentially directed feed inlet and there being an underflow outlet at the end of *e a. °•said separating chamber remote from said first portion, wherein the separator is 4. adapted to separate the oil and water components in a mixture when infed into said br separating chamber via said feed inlet, one said liquid component emerging from 15 in said overflow outlet and the other liquid component passing through said third S**s portion in a direction away from said second portion to emerge from said underflow outlet of the separator; and means anged t entran an emulsion le .0 breaker material into the liquid mixture to be separated, prior to feeding the mixture to the separator. 20 6. ar

2. The cyclone separator system of claim 1 wherein 0.04 A 4A rnd, 2 0.10, m S. where A, is the total inlet feed area to the separating chamber, and d, is the ot diameter of the first portion. o 25 sa

3. A method of operating a cyclone separation system for separating oil and O° water components of a liquid mixture wherein one component of the mixture is in w the form of droplets in the other component and including a cyclone separator in having a separation chamber with first, second and third contiguous portions lic arranged in that order, the first portion being of greater diameter than the second 30 Ur portion and the third portion being of lesser diameter than the second portion, the bI 91Q521,dbwspeDl19.oullspc 4 17 v rT ^901112,dbwspc.019,oullcllspc,6 I i

18- first portion having an overflow outlet at the end thereof opposite to said second portion and at least one tangentially directed feed inlet and there being an underflow outlet at the end of said separating chamber remote from said first portion; the hydrocyclone separator being adapted to separate the oil and water components of the mixture when the mixture is infed into the separating chamber via said feed inlet, one liquid component emerging from said overflow outlet and the other liquid component passing through said third portion in direction away from said second portion to emerge from said underflow outlet; wherein the method is characterised by adding an emulsion breaker material to the liquid 10 mixture upstream of the feed inlet prior to feeding the mixture to the separating chamber. S* 4. The method of claim 3 and further including entraining the emulsion breaker material into a stream of the incoming mixture prior to feeding the mixture into the feed inlet. 5. The method of claim 3 wherein the second portion is of a length which is at least ten times its diameter adjacent the first portion. 0, 6. A cyclone separator system comprising elements designed, sized and arranged for treating a mixture for separating oil and water components of a liquid mixture wherein one component of such mixture is in the form of droplets in the other component and wherein said separator has a separating chamber having an overflow outlet at one end thereof, at least one tangentially directed feed inlet near said one end and an underflow outlet at the other end of said separating chamber opposite said one end, wherein the separator is adapted to separate the oil and water components in a mixture when fed into said separating chamber via said feed inlet, one said liquid component emerging from said overflow outlet and the other liquid component passing through said separating chamber to emerge from said underflow outlet of the separator; and means aranged to entran an emulsion breaker material into the mixture to be separated, prior to feeding the mixture to 910521,dbwspe.19,outclpe,18 9l0521,bwspcb19,ouelclIspei8 O 16- 9011 12~dbNwvpc.0j,ouacI1.5pcS5 19 the separator. 7. A method of operating a cyclone separator to separate oil and water components of an oil/water mixture wherein an emulsion breaker material is added to the oil/water mixture to be separated, prior to feeding the mixture to the separator. H i 4. I I h 0 0 1 S S t 0050 S 0 0e 000 0 00 S 1) DATED this 24th day of July, 1991. CONOCO SPECIALTY PRODUCTS, [NC. By its Patent Attorneys DAVIES COLLISON 910724,dbwspc.019,oulet1.sp,19