US2467742A

US2467742A - Centrifugal bowl with reciprocating valve for separating sludgecontaining liquids

Info

Publication number: US2467742A
Application number: US536462A
Authority: US
Inventors: Hanno Tore Verner
Original assignee: De Laval Separator Co
Current assignee: De Laval Separator Co
Priority date: 1943-07-13
Filing date: 1944-05-20
Publication date: 1949-04-19
Anticipated expiration: 1966-04-19
Also published as: GB574667A

Description

April 19, 1949. T. v. HANNO 2,457,742

' CENTRIFUGAL BOWL WITH RECIPROCATING VALVE FOR SEPARATING SLUDGE-CONTAINING L IDS fan/613. 25 /M/Wra/f y Aprll 19, 1949. T. HANNO 2,467,742

CENTRIFUGAL B WITH RECIPROCATING VALVE Foa SEPARATING sLUDGE-CONTAINING LIQUIDs Flled May 2O 1944 2 Sheets-Sheet 2 5)/ @man Mem 4,7

Patented Apr. 19, 1949 CENTRIFUGAL BOWL WITH RECIPROCAT- ING VALVE FOR SEPARATING SLUDGE- -CONTAINING LIQUIDS Tore Verner Hanno, Stora Essingen, Sweden, as-

signor to The De Laval Separator Company, New York, N. Y., a corporation of New Jersey Application May 20, 1944, Serial No. 536,462 In Sweden July 13, 1943 Claims.

' ing problems of this kind it is therefore preferred to use centrifugal bowls provided either with small nozzles in the wall of the bowl and designed for continuous discharge of the'sludge, or with devices for intermittent discharge of the sludge during operation. In the latter case a construction of centrifugal bowl is generally used which permits the upper or the lower part to be moved axially relative to the other parts of the bowl, a slot thereby being formed thru which the contents of the bowl escape. Such a construction, however, has the convenience that a dry sludge cannot be discharged, because the liquid contained in the bowl i'lows out together with the sludge, and this entails the further inconvenlence that the supply of liquid to the bowl must be shut oil? each timethe bowl is to be emptied. l

With a view to avoiding these inconveniences a plurality of devicesl comprising openings or channels in the bowl wall have been suggested. In these constructions the openings are covered either by an axially movable slide or by valves, suscptibleof being opened during operation. The inconveniences with the known devices comprising a slide are the difficulty to obtain large packing rings of suicient durability and capable of making a tight joint, and above all to get the opening intervals sufciently short, so that only part of the sludge contained in the bowl is discharged each time. The valves .heretofore suggested are complicated and sensitive and often untight, because sludge particles easily penetrate between the cone and the seat of the valve. The object of the invention is an arrangement in centrifugal bowls, the wall of which is provided with channels or openings for the discharge of the sludge separated in the bowl, which channels or openings are covered by one or more movable members. for instance slides or the like, provided with openings which, when the movable members occupy agiven position, communicate with corresponding openings in the bowl wall, and is characterized in that each outlet opening in the bowl wall is provided with a tightening device, e. g. in the form of an elastic pack- 2 ing, collar, etc., making a tight joint both with the bowl wall and the slide. In a preferred construction the packing is thereby fixed to the bowl wall by means o f an annular nut or the like. The pressure establishing the tightjoint with the slide is generated both by the centrifugal force and the liquid pressure. In order to enable quick opening and closing each outlet opening should advantageously be provided with a small slide.

Figure 1 of the accompanying drawing shows one embodiment of the invention in longitudinal section. Figure 2 is a cross section on the line 2-2 of Figure 1. Figures 3, 4 and 5 are views in longitudinal section of other embodiments of the invention. k

In all figures the following denominations are used: I is the lower part or shell of the centrifl' ugal bowl, carried by a bowl spindle 2. 3 is the upper part or top of the bowl, and 4 its annular outlet for separated liquid; 5 a coupling ring by which the bowl top 3 and the bowl shell I are held together. unseparated liquid, and l is the supply pipe for the liquid. 38 is a pile of conical discs. On its largest inner diameter the bowl shell I is provided with a number of round openings 8, each of which opens into a cylindrical chamber 9, positioned at right angles to the openings and communicating with the outside of the bowl thru the oblong opening I0. The cylindrical chamber 9 is provided with an exchangeable lining II and its upper end is covered by a screw-plug I2; in the chamber 9 there is a cylindrical slide I3, provided on the middle with a plane surface I4. An opening I5 is provided at right angles to the surface I4. f

In each of the openings 8, which are provided with a threaded part I6, is arranged a sleeveor cup-shaped packing I1 having a central opening I8 and a flange I9, the latter being squeezed fast to the bowl shell I by the annular nut 20 andthe outerv part of which contacts with the plane surface I4 on the slide I3. The length of the slide I3 is less than that of lthe cylindrical chamber 9.

On the lower side of the centrifugal bowl two receiving chambers 2l' and 22 are arranged into which a Iservo liquid can be fed vthru the

stationary tubes

23 and 24. 'The chamber 2| communicates with the lowermost part of the cham- 6 is a receiver and distributor of ber 9 by a channel 25 and the chamber 22 with the uppermost part of the same chamber thru a channel 26.

In the embodiment according to Fig. 1, the bowl shell I is provided with a drain channel 21 running from the upper part of the chamber 9 to the outside of the bowl and located at a distance from the lower side of the screw plug I2 approximately equal to the difference between the length of the chamber 9 and that of the slide I3, that is the length of stroke of the slide. Another channel 28 is provided at the same distance from the bottom of the chamber 9. The opening I in the slide is so located as to communicate with the opening I8 in the packing I1 when the slide occupies its highest position.

The bow] operates in the following manner.

Servo liquid is fed thru tube 24 into the chamber 22 whence it passes thru the channel 26 to the upper end of the slide which is thereby forced down to its lower position, so that the communication between the openings I5 of the slide and the opening I8 of the packing is interrupted. The supply of servo liquid is now shut off, and the liquid contained in the chamber 22, the channel 26,-

and the upper part of the chamber 9 escapes thru the opening 21, since this is not covered. When a suitable amount of sludge has accumulated in the sludge space of the bowl, servo liquid is introduced into the chamber 2i and is conducted thru the channel 25 to the lower end of the slide, which is then forced up until the openings I5 and I8 communicate, whereupon the supply of servo liquid is shut off. When a suitable amount of sludge has been thrown out, the opening in the bowl is closed again by feeding liquid into the chamber 22. It is thus necessary to use servo liquid only at the opening and closing intervals, and consequently the consumption of such liquid is very small.

If the opening interval must be very short in order to prevent liquid from escaping with the sludge, the construction of slide shown in Fig. 3 may be used. The opening I5 of the slide is placed in such a manner that the communication between the openings I5 and I8 is interrupted both in the uppermost and the lowermost position of the slide, that is the openings communicate with each other only when the opening I5 is passing the opening I8. By regulating the supply of servo liquid it is possible to change the speed of the slide and thus to shorten the opening interval down to a fraction of a second. In that case only one of the

tubes

23 and 24 need be used for a complete emptying operation.

In order to make a satisfactory tight joint the packing I1 should be made of an elastic and comparatively soft material, but this entails rapid wear of the packing in case hard sludge particles penetrate between the packing and the slide. With a view to preventing this, the packing I1 in Fig. 3 is provided with a sleeve 29 of metal, Bakelite, or another hard and resistive material. The sleeve should have sharp edges, especially on its inside, on the part contacting with the slide, because sludge particles are then prevented from getting between the slide and the packing, In order to avoid deformation of the cylindrical part of the packing sleeve by the high interior pressure, a reinforcing sleeve of metal. or the like may be arranged around this part, or the opening 8 may be so dirnensioned, as shown in Fig. 3, that there is only a small play between the packing sleeve and the wall of the bowl shell.

Although only two embodiments are illustrated,

it will be understood that a great many modifications are possible within the scope of the invention. The packing sleeve I1 need not have any special shape or be of any special material. It may, for instance, be in the form of metal bellows 30 (see Fig. 4) to which packing material is vulcanized. Instead of supplying servo liquid at both ends of the slide, a spring 3| (see Fig. 5) may be arranged at its one end by which the slide is forced back into its initial position. In this case a drainage must however also be provided, for instance in the form of a small opening 32 thru which the servo liquid escapes from the chamber 9.

What I claim and desire to protect by Letters Patent is:

1. In a centrifugal bowl the wall of which encloses a number of chambers extending parallel to the axis of the bowl, the bowl wall having discharge openings one between each chamber and the outside of the bowl, the bowl wall having inner openings one between each chamber and the inside of the bowl, sliding members, one in. each chamber, each having a longitudinally extending plane inside surface and a through orifice adapted, in one position of the sliding member, to connect the two openings, means, including a channel through which a servo liquid is adapted to flow, whereby the movement of each sliding member is controlled, and in each inner opening a packing device having an opening communicating with the corresponding inner bowl wall opening and making a tight joint both with the bowl wall and with the plane surface of the sliding member.

2. A centrifugal bowl comprising a wall having an outlet opening communicating with the interior of the bowl, a packing device mounted in the opening and defining a passage for the discharge of solid particles and sludge separated in the bowl, the packing device making a tight joint with said wall to seal the opening except for said passage, a reciprocable member slidable in the bowl wall and having a surface maintaining a tight joint with the packing device around said passage in the movement of the member, said member being operable in its movement to alternately open and close said passage, and means for controlling the movement of the sliding member.

3. A centrifugal bowl as defined in claim 2 in which the packing device includes a flexible element having a wear-resistant sleeve defining said passage and contacting said surface of the slidable member.

4. In a centrifugal bowl the wall of which is provided with a plurality of separate openings communicating with the interior of the bowl for the discharge of solid particles and Ysludge separated in the bowl, sliding members, one covering each opening, each sliding member being provided with an outlet, means, including a channel in which a servo liquid is adapted to flow, by which the movement of said member is controlled, and a packing device in said opening; said packing device comprising an elastic cup-shaped member having a part contacting the sliding member and having an opening in said contacting part communicating with the corresponding inner bowl opening and having, around the other end, an exterior flange, and an annular nut securing the said flange to the bowl wall, thereby making a tight joint with the bowl wall and with the plane surface of the sliding member.

5. In a centrifugal bowl the wall of which is zum 5 provided with a plurality of separate openings communicating with the interior of the bowl for the discharge of solid particles and sludge separated in the bowl, sliding members, one covering each opening, each sliding member being provided with an outlet, means, including a,f channel in which a servo liquid is adapted to flow, by which the movement of said member is controlled, and

Va packing device in said opening; said packing device comprising a cup-shaped flexible member having a part contacting the sliding member and having itself an opening in said contacting part communicating with the corresponding opening communicating with the interior of the bowl, and a, wear-resistant sleeve surrounding the opening adjacent the sliding member and in contact therewith.

TORE VERNER HANNO;

REFERENCES CITED Thefollowing references are of record in the tile of this patent:

5 UNITED STATES PATENTS Number Name Date 1,635,482 Joyce July 12, 1927 1,921,181 Fawcett Aug. 8, 1933 lo 2,022,815 Strezynski Dec. 3, 1935 2,087,727 Bath July 20, 1937 2,091,329 Nyrop Aug. 31, 1937 2,126,864 Bath Aug. 16, 1938 FOREIGN PATENTS l5 Number Country Date 22,085 Germany June 27, 1883 e 451,251 Great Britainl July 31, 1936