US2294719A

US2294719A - Hydraulic disruption of solids

Info

Publication number: US2294719A
Application number: US355141A
Authority: US
Inventors: Court William Frederick
Original assignee: Shell Development Co
Current assignee: Shell Development Co
Priority date: 1940-09-03
Filing date: 1940-09-03
Publication date: 1942-09-01
Anticipated expiration: 1959-09-01

Description

t. 1, 142. w. F. COURT 2,294,719

HYDRAULIC DISRUPTION OF SOLIDS Filed Sept. 3, 1940 4 Sheets-Sheet 1 III a Fig.9

Sept. 1, 1942. w. F. cou 'r f 2, 294,719

HYDRAULIC DISRUPTION, OF soups I Filed Sept; 3,1940 5 4-. Sh eefcs-Sheet 2 Sept. 1, 1942. w. F. couRT ',4,7E9

HYDRAULIC DISRUPTION 0F SOLIDS Filed Sept. 3, 1940 4 Sheet-Sheet s 1 a -e\ L 73 \nvenfor WiHiam E Cour? hi5 W AL Rubi Spt. 1, 1942.,

W. F. COURT HYDRAULIC DISRUPTION OF SOLIDS Filed Sept. 3:, 1940 4 Sheets-Sheet 4 \nvenfor 1 WiH'mm F. Court Patented Sept. 1, 1942 UNi'EED STATES HYDRAULIC DISRUPTION orsoams Application September 3, 1940, Serial No. 355,1t1

3 Claims.

This invention relates to the cleaning of vessels which contain solids, like carbonaceous material, particularly deposits of coke produced by the carbonization of hydrocarbon oils, such as reaction and coking chambers employed in petroleum cracking plants and the like and asphaltic material, especially the solid, brittle kind. While the process may be applied to the removal of various types of carbonaceous material from diverse forms of apparatus, it is particularly useful for the removal of porous coke of the type produced by heat contained within the body of the oil. For convenience, in the following description the application of the process to the cleaning of a vertical reaction or coking chamber of the type used in connection with a Dubbs cracking unit will be described, it being understood that the process may be applied as well to a horizontal reaction chamber, and to containers of other shapes, as well as to the removal of similar types of porous coke or asphaltic materials from containers or conduits in which coke has been deposited due to the carbonization of oil by external as well as internal heat.

The conventional method of removing petroleum coke from cracking plant reaction or coking chambers involves hanging a steel cable in a series of spirals inside the chamber before the unit is placed in operation, and the withdrawal of the cable after the termination of a run by means of a steam hoist. The withdrawal of the cable breaks up the body of coke, discharging the same through a manhole. Following this, several men enter the chamber and re move the coke adhering to the chamber walls with pickaxes. Such a method is objectionable in that it is time consuming, since th chamber must be cooled to a point at which men can work within it; it is hazardous to workmen; and iron wire used to suspend the steel cable is with drawn together with the coke, rendering it useless ior many purposes without subsequent operations for separating pieces of metal.

It is the purpose of the present invention to provide an improved method and apparatus for removing carbonaceousmaterials, such as coke and the like from containers, which is less laborious than those heretofore employed, consumes less time, is more economical and is less hazardous than methods now employed.

It is a further object to provide a hydraulic method of removing coke and the like in which the coke will be free from metallic bodies. Still another object is to provide a novel apparatus {or carrying out the process herein described.

Other objects of the invention will become an parent from the following specification, taken to- .gether with the drawings forming a part thereof, in which a representative embodiment of the process is illustrated, it being understood that the process is not limited to the specific steps illustrated, nor to the cleaning of chambers of the particular type or shape shown.

In the drawings, Figure 1 is a perspective view of a cylindrical reaction chamber showing the general layout of the de-coking system; Figure 2 is an enlarged perspective view of the water feed pipe guide; Figure 3 is a perspective view of the.

.main nozzle head; Figure 11 is a longitudinal sectional view of the nozzle employed with the nozzle head according to Figure 10; Figure 12 is a perspective view of the blind flange adapted to be bolted to the upper section of the nozzle head of Figure 10; and Figure 13 is an elevationview of a modified, form of nozzle head suitable for effecting the first two steps of the process. Figure 14 is a vertical sectional view of the reaction chamber illustrating the step of the coke removing process as shown in Figure 6 according to another embodiment of the invention. Figure 15 is a sectional elevation of another modified form of nozzle head suitable for effecting the first two steps of the process. Figure 16 is a plane view of Figure 15, looking up from below. Figure 17 is a detailed elevation, partly in section, of the swivel and hydraulic motor shown at the top of Figure 14.

The present process is based on the discovery that carbonaceous materials of the type described above can be efiicaciously broken up and removed from containers by the action of a jet of water directed so as to have a cutting action on the deposit of carbonaceous material. This is effected by directing the water by means of a suitably designed nozzle so as to cause a great impact or reaction on the body of the solid to be removed over as small an area as possible. In this manner the primary action of the water is to cut the solid material into lumps, and erosion is minimized. For the main cutting or disrupting operation, I prefer to employ water jets lower velocities are employed, or when the design of the nozzle is such as tocause the jet to break up the cutting action is materially reduced and erosion is increased. This materially increases the time required for the removal of the solid and is, moreover, often undesirable, since it is frequently advantageous to produce maximum lump and egg size coke. As an example, I mayemploy a jet of water from a inch in diameter nozzle, with a velocity of 380 feet per second. Such a jet will cause an impact of about 212 lbs. over an area only slightly larger than 0.11 sq. in., the opening of the nozzle. I am, however, not restricted to the specific examples herein disclosed.

The method according to the present invention, according to the preferred mode of operation, comprises the steps of cannulating the body of the material to be removed, either by means of a jet of water or of a drill to provide a well or tubular opening, and disrupting the material by a radially outwardly directed cutting jet of the type described above from the opening. To permit the apparatus required to direct the cutting jets to be introduced into the opening, the cannulating operation may be carried out in two steps, a small opening being made in the first step, and the opening being enlarged or reamed in the second step.

The process may be applied to any solid material (not soluble in water) which can be disrupted or cut by a jet of water producing impacts up to 250'pounds against the solid, and is not restricted to the cutting of carbonaceous deposits. The invention may be better understood from the following detailed description.

Referring to the drawings, I represents a coke chamber of a usual cracking installation, supported by a foundation or pedestal 2 and provided with an upper chamber head manhole 3 and a lower manhole 3a (see Figure 4). The tower 4 is mounted on top of the coke chamber and is provided with a pair of vertical tracks 5 in the form of channel bars. A pipe guide 6 is mounted to have a vertical sliding movement I9 adapted to be bolted to the chamber head manhole. Plate I9 is apertured to avoid pressure, and carries brackets 20 supporting a guide plate 2I. Plates I9 and 2I are centrally perforated to permit the water feed pipe 9 to extend downwardly into the chamber, and to guide the pipe in its vertical movement. A foot brake lever 22 carrying a breakshoe 23, engageable with the water feed pipe 9 is attached to the brackets 20.

The pedestal 2 carries an angle bar 24 having holes 25 to receive pipe guides (not shown) forguiding an upwardly convex apron used as av connecting piece between coke cars to prevent spillage of coke on the tracks during loading operations, when the cars move into position. A water shedding shield 21 (see Figure 3) is adapted to be fastened to the bottom of the lower chamber manhole 3a by hooks 25; it has a medial slot 28, adapted to permit the water feed pipe to extend below it, as described below, and upturned flanges at its periphery and along the slot 28.

A trough 29 located below the pedestal 2 is provided to lead off water. into a settling basin 30. A screen BI is located across the settling basin 30 which is connected to the surge tank I0 via conduits 32. A pair of concrete aprons 33 direct water into the trough 29. Rails 34 for the side dump coke cars pass beneath the coke chamber I.

A piercing 6r spear nozzle 35 (see Figure 7) provided with a constricted throat 3B and a flaring orifice 31 .is adapted to be secured to the water feed pipe by means of an externally threaded boss 38, and is shaped to have a small external diameter, co-extensive with the exteriorof the water feed pipe 9.

The reaming nozzle head (see Figures 8 and 9) comprises a hollow body portion 39 rotatably mounted by means oi. roller bearings, on a central pipe having a threaded boss 40 adapted for connection to the water feed pipe. A plurality of elbows H are attached to the body 39 in communication therewith and with the feed pipe 8, and carry nozzle tips 42 directed so as to cause water issuing therefrom to rotate the nozzle head by the reaction of the water on the elbows. One

along the tracks, supported by a cable passing through a block I, and wound about a drum 8 operable by a suitable source of power. The pipe guide 6 carried a vertical water feed pipe 9 concentrically with respect to the coke chamber. The water may be supplied thereto from surge tank I0,'via pump II, riser pipe I2, hinged connection I3, pipe I4, and a pair of pipes I5 and.

IS. The pipes I5 and I6 are hinged about a horizontal axis with respect to the pipe I4, as

pair of oppositely disposed nozzles is directed downwardly at an angle of about 30 with the horizontal and the other pair is directed upwardly at an angle of about 45 horizontal; A pair of scrapers 43 provided with sharp points is secured to the top of the body 39.

The main nozzle head which carries the cutting nozzles (see Figures 10 to 12) comprises an upper and a lower section and is preferably nonrotatably connected to the feed pipe 9. The upper section comprises a pipe 44, adapted to be threadedly connected at its upper end to the water feed pipe 9, and carries a flange plate 45, threadedly secured at its lower end. Two curved pipes 46, in communication with the interior thereof, carry nozzles 41, and are shaped to direct a stream of water downwardly therefrom at an angle of about 30 with the horizontal, nozzle axes being skew with respect to the axis of the pipe 44, whereby the reaction of the water imparts a turning'force to the nozzle head. The nozzle 41 as shown in Figure 11, comprises a tapering body portion 48 and an externally threaded coupling portion rearwardly thereof, having a cylindrical recess 49 shaped to retain a bushing 50 carrying axially extending straightening vanes 5I. It is important to design these nozzles and stellite alloy and ground.

Figures 15 and 16 illustrate another modified I form of nozzle head suitable for combining the f piercing and reaming operations. A central pipe the nozzles 410 so as to produce a, jet which will not substantially break up before striking the body of the coke, whereby the cutting action will be at a maximum, since my process is essentially one of cutting the coke, as distinguished from erosion. It is also desirable to design the nozzle tips 42 and the nozzle 35 to avoid breaking up and scattering of the jet asmuch as possible.

The lower section comprises the vertical pipe 52 surmounted by a flange plate 53-provided. with bolts 54 for attachment to the flange plate 45. A pair of nozzles "a, constructed like nozzles 41, is connected to the lower end of the pipe 52 so as to swing upwardly about swivels 55. Chains 56 normally support the nozzles 41a at an angle of i5 are preferably made of case hardened steel since 5 they are subjected to considerable abuse.

Referring to Figure 13, a modified form of nozzle head suitable for combining the piercing and handlin reaming operations is shown. It comprises a central pipe 60, provided with a threaded boss 8| adapted for attachment to the water feedplpe 9.

An annular rotating head 52 is secured to the pipe 60 by means of roller bearings, and carries a plurality of nozzle tips 42a, similar to the tip 85 82 shown in Figure 9. The nozzle'tips are inclined downwardly about 30 below the horizontal, and supplied with water from the pipe 9 and through curved conduits 63, supported by cross flanges 56 which areattached to and rotatable with the head 62. A drill 65 is mounted beneath. the cross flange 64. The cross flanges 54 aredownwardly convex and their outer edges are shaped as cutting edges, preferably. made of- 88 is provided with a threaded boss 61 adapted for attachment to the water feedpipe by means although the hole is pierced through from the of a union, part of which is shown at 13. A coupling 68 is provided in the lower end of the central pipe 65, into which a stub nozzle 59 may be threaded. The oriflce 10 in the stub nozzle 69 is preferably, although not necessarily, offset to the extent of about 5. Cross flanges H are welded to the central pipe and provided with beveled cutting edges on their outer peripheries at 12. A plurality of cutting nozzles42c are' threadedly mountedin the central pipe 66 as so shown. These nozzles 420 are in this form of cutting head purposely set at opposing angles so :that the reaction force provided by the high pressure water discharge is counterbalanced in each pair of, opposite nozzles. 65

v when using the type of cannulatlng head shown in Figures 15 and 16, the water feed pipe 9 is rotated preferably by means of a pneumatic orhydraulic motor, as shown in Figures 14 and 17. The pneumatic or hydraulic motor 74 is mounted by means of a bracket 15 to the special swivel unit 16. The motor driven gear ll engages gear 18 which is mounted on water feed pipe 9. A flexible line 19 supplies air or liquid trically driven motor may of course be equally I well used at ll if a convenient power source is at hand.

Referring particularly tothe swivel 16' of Figure 1'7, an outer casing 88' is provided with

end plates

89 and 90. The rotatable water feed pipe 9 bears on load bearing 83 and radial thrust bearing 82,

a spacer sleeve 9| being provided between the two bearings. A stufllng box assembly 8! which may be adjusted by nut and bolt assemblies as at 92 is provided between-waterreed pipe 9 and water supply pipe 'Qa. Lubricant filler plug 84 and drain plug 85 permit introduction of -lubri- I cant to thebearlngs '82 and 83.

Gasket closures j

86 and 81 preventleakage of lubricant from v e bearing assemblies.

The operation of removing coke according to this invention proceeds as follows:

The coke chamber is first cooled in anysuit- {1 '7 able manner, as by the introduction of steam for a period of from 15 to 30 minutes followed by the 1 introduction of water over a period from 30 minutes to two hours. This may be introduced through the regular connection or pressure coni duits provided for thispurpose. 'It is not neces-- sary in this processto cool the coke chamber to the extent necessary in the cable method. The

method of operation according to a preferred embodiment then comprises the following three steps: v First step (illustrated in'Fig'ure 4) The chamber is unh'eaded at the top and botl tom and the water feed pipeguide secured to the upper manhole head 3. The pipe guide 8 is raised to the top of the tower and the spear nozzle 35attached to the lower end of .the pipe 9.

This assembly is then lowered into the chamber and water under highpressure such as, for ex- 1 ample, l200'lbs. gauge measured at the pump,

supplied thereto, causing a high velocity jet of water to be directed downwardly. The rate of discharge may, for example, be 400 to 750 gallons per minute or higher, using a spear nozzle 8 a 6 inches long with a or inch throat and a or one inch orifice. The water pierces a vertical hole through the coke of sufficient diameter to permit free movement of the feed pipe. Dur-' ing this operation the pipe is gradually lowered,

being guided by plates is and M. In most cases,

top, the water escapes through the lower manhole without flooding the chamber. The fine particles of coke displaced by this operation are diffused into the main body of the coke bed.

encountered it may also be necessary to raise the assembly a foot or two above the obstruction and permit it to drop, repeating this operation until the strata have been broken through, using the hoist cable and power driven drum 8, or an aunillary hand operated hoist for this purpose.

To reduce the required height of the tower l the feed pipe 9 may comprise two or more sections, successive sections being added when the pipe line 6 has reached its lowermost position at the bottom of the tracks 5.

under pressure to the motor ll, A steam or elec- The first step may also be effected by drilling,

water being preferably introduced to wash out the loosened material. Alternatively, a hollow pipe may be mounted in the coke chamber prior to coking, and this may be withdrawn by means of a hoist, leaving a central hole.

Second step (illustrated in Figure 5) The object of the second step, which may sometimes be omitted, is to increase the size of the initial hole to about 18 to 24 inches in diameter in order that the nozzle head may be used in the last step without fouling the coke bed and may be regarded as a continuation of the cannulating operation described in the first step. Following the completion of the first step, the nozzle extends through the lower manhole 3a and below the coke chamber. The water shedding shield 21 is placed beneath the coke chamber so as to cause the pipe 9 to extend through the slot 28 and the reaming nozzle head is attached in place of the H more nozzles 42 with inch diameter outlets.

The pipe and nozzle head are then raised steadily to the top of the chamber and upon reaching the top the water is turned off. The scrapers 43 are provided primarily for the purpose of preventing coke bridging on the head and stopping the rotation, since the main cutting action is eiiected by the water.

The second step may be carried out simultaneously with the first step, as by mounting the piercing nozzle on the reaming nozzle head to discharge in the direction of the scrapers 43, the water feed pipe 9 being in this arrangement attached to the opposite end of the body 39. Alternatively, the nozzle head shown in Figure 13 may be mounted on the feed pipe 9 from a position above the coke bed, and the water turned on. The reaction of the water on the nozzle tips 42a will cause the -head 62 to rotate at a high velocity, thereby causing the drill 65 and the edges of the flanges 64 to cut the coke. The water will wash away the disintegrated coke, as described above. radially beyond the termini of the nozzle tips 420., the latter will move downwardly into the hole, and enlarge it to the dimension required for the third step.

Third step (illustrated in Figure 6) This is the final step during which the main body of coke is disrupted and completely removed from the chamber. It is preferably carried out following the completion of the first and second steps, but may be carried out simultaneously with either or both, as by attaching the main nozzle head to the bottom of the reaming nozzle head. In a preferred mode of operation,-

Since the flanges 64 extend and jetting is started immediately after the nozzle is in position above the manhole neck. Due to the angular disposition of the nozzle, the assembly, including the water feed pipe, rotates under its own power, the rate 'of turning being preferably regulated by means of the foot brake 2223 not to exceed about 24 revolutions per minute, whereby the jets assume a plurality of successive orientations. The rate of turning, however, depends upon the size of the chamber being cleaned, it being desirable to regulate the rotation so that one rotation will make a complete circular cut into the coke body. With the water pressure still on, the assembly is raised about 6 or '7 inches and rotation continues. This procedure is followed until approximately 5 feet of coke have been removed from the bottom of the chamber. The water is then shut off, the assembly is lowered, water shedding shield reattached, the blind flange 51 is disconnected, and the lower section of the main nozzle head is coupled to the vertical pipe 44 by means of bolts 54. The shield 2'! is removed, and complete assembly is then raised into the bottom of the coke body, the nozzle 47a being folded upwardly to permit passage through the manhole neck, and assuming the position shown in Figure 10 after having entered the coke chamber. The complete assembly is raised into the coke chamber to a position at which the frustrocom'cal surface of revolution defined by the axes of the nozzle 41 is just below the frustro-conical bottom of the coke body, as shown in Figure 6, full water pressure is applied and jetting restarted. The rate of water discharge may, for example, be 450 to 750 gallons per minute using nozzles 41 and "a having inch orifices. The nozzles 4111 direct jets of water upwardly to impact on the chamber wall at the same height and preferably at from the points of impact of the downwardly directed jets from the nozzles 41, although the jets from the nozzles 41a may be directed somewhat lower and to different orientations. The procedure from this point on is similar to that described in the second step, the water feed pipe and nozzle head being procedure raised until all coke has been completely removed from the coke chamber, and the rate of turning being regulated to about 2 to 4 regulations per minute.

By way of example, it may be stated that the total pumping time for the three steps in removing coke from a chamber forty feet high and ten feet in diameter, using the rates of flow and nozzle sizes given above, is usually between one First step The chamber is prepared for the decoking operation in a manner similar to that described in the first step of the three-step method of operation. The combined cutting and reaming nozzle head shown in Figures 15 and 16 is then attached to the water feed pipe and the assembly gradually lowered as previously described. In this case, however, the cutting and feed pipe assembly is rotated by means of the hydraulic motor, the speed being controlled to about 30-35 R. P. M. during the initial cannulating operation. The size of the hole may be controlled to a large extent by the speed of rotation of the cutting head. By operating at approximately 30-35 R. P. M., a hole 2 to 3 feet in diameter will be cut, depending upon the hardness of the coke bed.

Second step After the cutting and reaming head has passed through the coke bed and out the bottom manhole of the chamber the cutting and reaming head is removed and a final cutting head, as shown at 80 in Figure 14 is attached. The final cutting head is similar in design to that disclosed in my copending application Serial No. 289,955, filed August 14, 1939, except that the cutting nozzles are not adjustable and, as in the reaming nozzles shown in Figures 16 and 17, do not provide any rotative reaction force. The assembly is then slowly raised, the speed of rotation being about l5-20 R. P. M. for the average coke chambers in common use for best results. Water pressures used and nozzle sizes are similar to those described in the three-step operating procedure.

During the jetting operations, a dump car is placed beneath the coke chamber to receive the mixture of water and coke. It was found that most of the coke settles to the bottom of the car and only the extremely fine mixture iswashed over the side or through the perforation of the car.

The water, directed by aprons 33, flows into the trough 29, carrying the coke with it. Any number of suitable settling basins such as the basins 30 may be provided. After the heavier particles of the coke have been settled the partially clarifled water passes through a screen 31 which retains the finer particles of coke.

The nozzles disclosed in this specification are claimed in my Patent No. 2,217,360, issued October 8, 1940.

The present application is a continuation-inpart of my co-pending application Serial No. 191,685, filed February 21, 1938, now Patent No. 2,245,554.

I claim as my invention:

1. In apparatus for hydraulic removal of coke from a coking chamber, the combination of a substantially rigid, vertical, vertically. movable conduit, guide means for directing said conduit centrally with respectto said chamber comprising vertical trackmeans extending. above said chamher, a pipe guide movable along said track means and attached to the upper end of said conduit and a housing located near the top of the chamber arranged for sliding "engagement with the conduit, means for imparting vertical movement to said conduit, means for supplying liquid under pressure to said conduit, and a rotatable reaction nozzle secured to the lower end the conduit constructed to impart a rotary motion to said nozzle upon the flow of liquid therethrough.

2. In apparatus for the hydraulic removal of coke from a coking chamber, the combination of a rigid, axially movable conduit, guide means adapted for attachment to said'chamber for directing said conduit through said chamber, means for axially moving said conduit, means for supplying liquid under pressure to said conduit, and a reaction nozzle head attached to'one end of the conduit constructed to impart a rotary motion to said nozzle head upon the flow of liquid and provided with a plurality of nozzles spaced along the axis of the conduit and directed to emit jets of liquid falling substantially in converging frustraconical surfaces of revolution.

3. In apparatus for the hydraulic removal of coke from a coking chamber, the combination of a rigid, axially movable conduit, guide means adapted for attachment to said chamber for directing said conduit through said chamber, a swivel joint near the upper end of said conduit, means for rotating the lower end of said conduit below said swivel joint, means for axially moving said conduit, means for supplying liquid under pressure to said conduit, a plurality of nozzles spaced along said conduit near the lower end thereof disposed to emit jets of liquid falling substantially in converging surfaces of revolution.

WILLIAM FREDERICK COURT.