US3140828A - Tank washing system - Google Patents

Description

4 Sheets-Sheet l T. R. GALANOR TANK WASHING SYSTEM July 14, 1964 Original Filed Feb. 26

INVENTOR. 7/7010: P GALA/v0 A7- Ale-V6 July 14, 1964 T. R. GALANOR TANK WASHING SYSTEM 4 Sheets-Sheet 2 Original Filed Feb. 26, 1963 INVENTOR I 750145 4 6402/10 flew July 14, 1964 T. R. GALANOR 3,140,828

TANK WASHING SYSTEM Original Filed Feb. 26, 1963 4 Sheets-Sheet 3 INVENTOR. I83 720/145 9 GALA Azromers July 14, 1964 T. R. GALANOR 3,140,828

TANK WASHING SYSTEM Original Filed Feb. 26, 1963 4 Sheets-Sheet 4 \\$VENTOR. 7Zma-s 1? 67411900 ,4 Nays United States Patent 3,140,828 TANK WASHING SYSTEM I Thomas R. Galanor, River-dale, N.Y., assignor to Theodore E. Ferris & Sons, New York, N.Y., a partnership Original application Feb. 26, N63, Ser. No. 261,027, now

Patent No. 3,121,027, dated Feb. 11, 1964. Divided and this application Get. 17, 1963, Ser. No. 320,600

Qlaiins. (Cl. 239-227) This invention relates to a system for washing the interior surfaces of tanks. It relates particularly to a system for washing the interior surfaces of tanks in a range of sizes suitable for the bulk containment of petroleum liquids. It relates more particularly to a system for washing the interior surfaces of bulk containment tanks or portions of tanks which form parts of the structures or supers'tructures of transport vehicles or vessels, especially ocean-going marine vessels.

The present application is a division of co-pending application Serial No. 261,027 filed in the United States Patent Office on February 26, 1963, and now United States Patent No. 3,121,027, issued on Feb. 11, 1964.

An exemplary system for washing tanks in ocean-going marine vessels intended to transport petroleum liquids in bulk which has been used for many years is one in which a n0zzle-carrying machine having two axes of rotation of its discharge nozzles at right angles to each other is suspended in a tank or tank bay on a hose through which the liquid is provided under pressure which serves as both the energizing fluid for a turbine forming part of the machine whereby the nozzles are driven, and the outlet fluid from the nozzles themselves which performs the washing function upon impingement against the interior surfaces of the tank. It is a requirement of this system that any tank being washed or cleaned by it be pumped continuously so that there is no accumulation of washing liquid within it, this liquid being at least somewhat contaminated with tank soil after impingement against the interior surfaces of the tank.

Heated salt water is used customarily as the driving and washing fluid in the aforedescribed system of the prior art, and, after use, is discharged overboard. Two general disadvantages or at least inconveniences accrue from this use and discharge or disposal. One is a more rapid consumption, that is, wearing thin of the steel work of tanks than would be the case were fresh water used. The other is the requirement either that a vessel clean its tanks only at sea and not in harbor to avoid harbor contamination by the discharge overboard of considerable quantities of water containing at least trace amounts of oil and other waste material such as metal scale, or that a special barge be brought alongside the vessel in harbor to receive the contaminated salt water eflluent.

Another requirement of the aforedescribed system which results frequently in some inconvenience in its employment is that when the nozzle-carrying machine which it uses is suspended in a tank having a depth such as that typical of the cargo tanks of ocean-going petroleum carriers it must be attended from time to time for step-wise lowering within the tank in order that there be complete, substantially full-pressure washing of all of the interior tank surfaces by the streams of water issuing from the machine. Additionally, the aforedescribed system is not ordinarily well adapted to permit the mixing of any kind of detergent with the water supplied to its characteristic machine.

In contrast to the aforedescribed system of the prior art cited for purposes of outstanding example, and considering the marine vessel tank cleaning problem exemplarily for this contrast and not by way of limitation, the tank washing system of the present invention employs and as one of its objects provides nozzle-equipped 3,146,828 Patented July 14, 1964 standpipes installed permanently within the several tanks or tank bays of a liquid cargo ship rather than a set of spray machines which have to be suspended at various heights within bays, and also move from bay to bay.

In further contrast to the aforedescribed system of the prior art and as another of its objects, the tank washing system of the present invention provides for the employment of fresh water rather than salt water with this water being reclaimed after use in prerinse, wash, and final rinse cycles or steps rather than being pumped overboard.

In still further contrast to the aforedescribed system of the prior art and as another of its objects, the tank washing system of the present invention is particularly well adapted and provides specifically for the employment of a water and detergent mixture for washing purposes in at least one of its operating steps or cycles, and obviates the discharge of contaminated wastes.

According to the present invention, each tank bay standpipe is installed in bearings allowing it to be rotated about a vertical axis. It is provided with at least one and normally a plurality of sets of Washing nozzles at various elevations, the nozzles being rotatable by jet reaction about horizontal axes, that is, axes transverse to the axis of the standpipe. Each standpipe is provided further with either an upper or a lower and normally both an upper and a lower set of driving or rotator nozzles which impose rotation upon the standpipe itself by jet reaction.

Fresh water or a fresh water and detergent mixture is supplied to each standpipe through a line coming from a heater and a pump. The pump takes suction from either a pre-rinse, wash, or final rinse water supply tank depending upon the particular cycle or portion of a cycle in which the system is operating. The tank or tank bay being washed or rinsed is kept drained by means of a return main and circulating line leading alternatively to at least one separator such as a centrifugal separator or a bypass around it, and then to a strainer and the suction side of the aforementioned pump for continuous circulation of liquid. Lines and connections are provided for restoration of fresh water to either the prerinse, wash, or final rinse water supply tank as appropriate upon the conclusion of a particular operating cycle.

The pre-rinse, wash, and final rinse water supply tanks are provided to be charged or replenished as necessary and appropriate from a de-emulsifier tank, a detergent tank, and a fresh water storage tank. When in opera tion, the separators discharge separated waste materials to a contaminated oil tank from which this waste may be discharged further to burners of any suitable kind. Liquid non-burnable materials throughout the whole system may be dumped overboard in substantially clean condition through a discharge line on the outlet side of the pump normally used to feed the standpipes.

The nature and substance of this invention as well as its objects and advantages will be more clearly perceived and fully understood by referring to the following description and claims taken in connection with the accompanying drawings in which:

FIG. 1 represents a diagrammatic arrangement of the tank washing system of this invention;

FIG. 2 represents a view in side elevation of a nozzlecarrying standpipe rotatably installed in .a ships cargo tank according to this invention;

FIG. 3 represents an enlarged perspective view of the upper and lower bearing and rotator nozzle portions, and the central portion of the standpipe of FIG. 2;

FIG. 4 represents an enlarged view in partly sectioned side elevation of the upper and lower bearing and rotator nozzle portions and a small part of the central portion of the standpipe of FIG. 2;

FIG. 5 represents an enlarged view in section and partly broken away taken through the standpipe of FIG. 3 along line 5-5 therein looking in the direction of the arrows;

FIG. 6 represents an enlarged view in section taken through the standpipe of FIG. 3 along line 6-6 therein looking in the direction of the arrows, and

PEG. 7 represents an enlarged view in side elevation of a portion of the 'standpipe of FIG. 2 taken along line 7--7 therein looking in the direction of the arrows at right angles to the looking direction of FIG. 2 itself.

Referring now to the drawings in detail, especially to P16. 1 thereof, two representative ships cargo oil tanks or tank bays are designated and 21. Within tank 26 there is a rotatable standpipe 22 which is provided with a plurality of sets of rotatable washing nozzles 23 at various elevations, and an upper and lower set of driving nozzles 24 and 25 which impose rotation upon the standpipe itself. A rotatable standpipe 26 similar in all essential respects to standpipe 22 is installed in tank 21. Details ofstructure and installation of these standpipes are illustrated and described in connection with other figures.

At their upper or inlet ends, standpipes 22 and 26 are connected respectively through suitable rotatable joints to branch feeder lines 27 and 28 respectively coming off of Washdown supply main 29. Branch lines 27 and 28 are provided respectively with stop valves 30 and 31 to allow either or both standpipes to be isolated from the Washdown main. Another branch feeder line 32 including a stop valve 33 is representative of additional connections made off of main 29 for other Washdown requirements.

Washdown main originates at heater 34 and is provided with a stop valve 35 just outside the heater. Valve 35 is provided in turn with a power operating device 36 which is energized through lines 37. These lines may be either hydraulic, pneumatic, or electrical lines, for example, depending upon the nature of operating device 36. Because of its operating device, stop valve 35 is subject to being controlled remotely. Although not illustrated specifically, valves throughout the system shown in FIG. 1 may be considered to have operators such as operator 36 Where appropriate to allow the whole system to be lined up and employed for general or selective washing of tanks by remote control.

Heater 34 may be a heat exchange or a heat transfer device of any suitable kind such as a shell-and-tube heat exchanger designed to be supplied with steam on its shell side for the heating of liquid material, principally water,

, on its tube side. Steam is furnished to the heater through line 33, and indication of steam conditions is provided by thermometer 39 and pressure gauge 40. In the steam connections to the heater, valve 41 is a temperature regulator valve provided with a stop valve on either side, and valve 42 is a bypass check valve.

On its shell side, heater 34 discharges condensed steam through connections 43 to a drain cooler 44. This cooler may be a heat exchange or heat transfer device of any suitable kind such as a shell-and-tube heat exchanger designed to be supplied with hot condensate drains from heater 34 on its shell side and relatively cool fresh water or a mixture of fresh water and detergent on its tube side. The outlet end of the tube side of drain cooler 44 is connected to the inlet end of the tube side of heater 34 by means of line 45 which includes a liquid flow indicator 46 having stop valves 46' and 46" on either side of it. On its shell side, the drain cooler is connected to the ships condensate system by line 47. In the connecting piping structure, valve 46 is a liquid level regulator valve provided with a stop valve on either side, and valve 49 is a bypass needle valve. On a Diesel-driven ship, exhaust gases rather than steam may be used for water heating.

The inlet end of the tube side of drain cooler 44 is connected by branch line 50 to water line 51 coming from the outlet or discharge side of Washdown pump 52 which is driven by any suitable prime mover 53 such as a steam turbine or an electric motor. Branch line 50 contains a stop valve 54. Water line 51 continues in a section 55 past the connection of branch line 50 and ties in to washdown supply main 29 beyond valve 35. Line section 55 contains a stop valve 56, and constitutes a bypass section or line around the drain cooler and heater.

Tanks 57, 5S, and 59 are respectively the pre-rinse, wash and final rinse water supply tanks. Tank 60 is the fresh water storage tank. Tanks 61 and 62 are respectively the detergent storage tank and the de-mulsifier storage tank. Pump 63 driven by prime mover 64 is a Washdown supplies transfer pump. Two series-connected centrifugal separators are designated 65 and 66. Tank 67 is the contaminated oil or refuse tank, and pump 63 driven by prime mover 69 is a refuse pump.

Line 70 is a cycle circulating line which is connected to the inlet or suction side of Washdown pump 52 through stop valves 71, 72, and 73, and duplex strainer 74. Prerinse water supply tank 57 is connected to line 70 between valves 71 and 72 by means of tank outlet line 75 including stop valve 76. Wash and final rinse water supply tanks 58 and 59 have outlet lines 77 and 78 and outlet stop valves 79 and 80 respectively, lines '77 and 78 connecting to each other and then to line 75 beyond stop valve 76 to make further connection to cycle circulating line 70.

Storage tank 60 may be supplied or replenished with fresh water through either line 81 coming from deck filling valve 82 or line 83 including stop valve 84 coming from the engineering spaces, for example, from fresh water tanks not shown which are fed from the ships evaporators. Lines 81 and S3 join to form a common line 85 including a stop valve 556 on the inlet side of the fresh water storage tank. Tank 60 has an outlet or suction line 87 which connects to cycle circulating line 70 just on the Washdown pump side of stop valve 72. Outlet line 87 itself includes stop valves 88 and 89, one near fresh water storage tank 60 and the other near the cycle recirculating line.

Detergent and de-emulsifier storage tanks 61 and 62- have outlet lines 90 and 91 and outlet stop valves 92 and. 93 respectively. Lines 90 and 91 join in a common line 94 connecting to the suction side of Washdown supplies. transfer pump 63 through inlet stop valve 95. Pump 63 has an outlet or discharge line 96 including a stop valve: 97 serving as an outlet stop or shutoff valve for pump- 63. This pump is also provided with a recirculating line 98 including a relief valve 99. Outlet line 96 divides into branches 100 and 101 connecting to wash and final rinse. water supply tanks 58 and 59 respectively through stop valve 102 in branch 1'00 and stop valve 103 in branch 101.. Line 104 is a Washdown return main into which wash-- down outlet lines 105 and 106 from ships cargo tanks. 20 and 21 are connected, these two outlet lines including; stop valves 107 and 108 respectively. Outlet line 109 including stop valve 110 connecting into return main 104'- is representative of additional connections made into this main from regions other than tanks 20 and 21 having: Washdown requirements. Stop valve 111 is included in. Washdown return main 164 just ahead of the T-joint off this main with de-emulsifier cycle circulating line 1121 from which leads away a separator suction line 113 con-- necting to the inlet side of centrifugal separator 65 through.

stop valve 114.

Separators 65 and 66 are in serially staged array with respect to water flow through them. Water outlet line 115 from separator 65 leads directly to the inlet connection of separator 66, and includes stop valves 116 and 117 which may be regarded respectively as the outlet stop valve for separator 65 and the inlet stop valve for separator 66. On their waste sides, separators 65 and 66 respectively have outlet lines 118 and 119 including stop valves 120 and 121. Lines 118 and 119 join in a common Waste line 122 to enter contaminated oil tank 67 through stop valve 123. Tank 67 has an outlet line 124 leading to the inlet side of refuse pump 68, and including a tank outlet stop valve 125 and a pump inlet stop valve 126. The refuse pump has an outlet line 127 in cluding a stop valve 128. Desirably although not necessarily for purposes of the present invention, line 127 leads to burners designed to handle oil mixed with at least traces of solid contaminants and some other liquids such as water, detergent, and de-emulsifier. Energization of pump 68 to withdraw waste material from tank 67 is effected by level sensing element 128 within the tank.

Separator 66 has a water or clean product outlet line 129 which may also be designated a tank return line. This line includes two stop valves 130 and 131 close to the water outlet connection of separator 66, and cycle circulating line 70 is taken off of outlet line 129 between these two valves. Line 70 itself includes a stop valve 132 fairly close to its connection to line 129. Water or other liquid may flow from separator suction line 113 into cycle circulating line 70 without ever going through the separators by being routed through bypass or wash cycle return line 133. This line, which includes stop valves 134 and 135, is taken oif of line 133 just ahead of stop valve 114 and connects into line 70 just ahead of stop valve 132.

A valveless cross-connection line 136 extends between water outlet line 115 from separator 65 and bypass line 133, connecting into line 115 between valves 116 and 117 and into line 133 between valves 134 and 135. By means of this line, nearby valves being set appropriately open or shut as will be apparent to those skilled in the art, liquid material flowing through separator suction line 113 may be routed through either one of separators 65 and 66 to the exclusion of the other.

Clean product outlet line 129 extends from separator 66 to final rinse water supply tank 59, and includes a stop valve 137 close to this tank. Shortly ahead of valve 137, a branch line 138 is taken off of line 129, and itself divides into two branch lines 139 and 140 which are connected to wash and pre-rinse water supply tanks 58 and 57 respectively through stop valves 141 and 142.

Washdown pump 52 is provided with an outlet stop valve 143 in its discharge line 51. It is also provided with a recirculating line 144 including a relief valve 145. Just beyond valve 143 a suitably valved overboard discharge line 146 is taken off of line 51. De-emulsifier cycle circulating line 112 including a stop valve 147 is taken off of pump discharge line 51 just beyond the overboard connection. Line 112 makes a cross joint in line 51 with a line 148 including a stop valve 149. Line 148 divides into three branches, 150, 151 and 152, which connect to pre-rinse, wash, and final rinse water supply tanks 57, 58 and 59 respectively through stop valves 153, 154 and 155.

Shown in dashed outline is a fire and emergency washdown pump 156 which is connected in lines 70 and 51 in parallel with pump 52. Pump 156 is a regularly installed ships pump which is ordinarily reserved for service on the fire main, but which may be employed in the Washdown system, that is, for tank washing purposes, in an emergency. Washdown pump 52, on the other hand, may be a pump specially installed for the Washdown system, or it may be a regularly installed cargo tank stripping pump where such a pump is available.

The tank washing or tank cleaning and gas freeing system of this invention operates in three fundamental steps or cycles as follows: (1) the pre-rinse cycle, (2) the wash cycle, and (3) the final rinse cycle.

To review the pre-rinse cycle operation of the tank washing system of the present invention, imagine that all valves shown in FIG. 1 are closed except valves 125, 126 and 128, and the valves allowing flow of steam into and condensate out of heater 34 and drain cooler 44. Imagine further that tanks 57, 58, 59 and 60 are full of fresh water and the tanks 61 and 62 contain working quantities of detergent and deemulsifier respectively. Tanks 20 and 21 are, of course, empty.

As a first step in the pre-rinse cycle operation, the following valves, starting from pre-rinse water supply tank 57, are opened: 76, 72, 73, 143, 54, 46, 46", 35, 56 (partly if at all), 30, 31, 33 (possibly), 107, 108, 109 (if valve 33 is opened), 111, 114, 116, 117, 130, 120, 121, 123, 132, and 71. These valves having been opened, Washdown pump 52 and separators 65 and 66, are started. The pump withdraws fresh water from pre-rinse tank 57 through lines 75 and '70, and discharges it through lines 51 and 52, drain cooler 44, line 45, heater 34, Washdown supply main 29, and branch feeder lines 27, 28, and 32 to standpipes 22 and 26 and any points of consumption connected to branch feeder line 32. Valve 76 is closed as soon as tank 57 has been substantially emptied by the action of pump 52.

For temperature regulation purposes, some of the water leaving pump 52 may be bypassed around drain cooler 44 and heater 34 through line 55. In any event, pre-rinse water delivered to the standpipe should have a delivery temperature and pressure of about F. and p.s.i.g. Water issuing from upper and lower driving or rotator nozzle sets such as sets 24 and 25 causes the standpipes to spin on their bearings about their vertical axes. Water issuing from intermediately located nozzle sets 23 causes these sets to rotate about axes transverse or horizontal with respect to the standpipes While of course they are turning with the standpipes themselves under the influence of reactive forces of steady jets of water discharging from the rotator nozzle sets.

Water discharged from the various nozzle sets on the standpipes impinges on the bulkheads, decks, and overheads of tanks 20 and 21, and in the course of an extended operation every portion of interior surface of the tanks will he struck directly by a water jet. As the warm streams of fresh Water impinge upon the tank decks, bulkheads, and overheads they remove gross amounts of liquid (oil) and solid (rust and scale) contaminants from these surfaces. Pre-rinse water and the contaminants which it has dislodged are withdrawn continuously through lines 105, 106, 109, 104, and 11.3 by the suction effect of pump 52 acting back through separators 66 and 65. Separator 65 effects an initial separation or cleaning of the Withdrawn liquid, and sends fairly clean water to separator 66 through line 115, and contaminants to refuse or contaminated oil tank 67 through lines 118 and 122. Separator 66 performs a final cleaning operation on the liquid material, essentially entirely water, which it receives, and discharges a stream of quite clean water into lines 129 and 70, and a small amount of contaminants into tank 67 through lines 119 and 122.. A rising level of contaminants in tank 67 causes pump 68 to be started by sensing element 128 with resultant discharge of at least some contaminant material from the tank through line 124 to burners not shown.

Water flowing in line '70 is returned to the suction side of pump 52 through strainer '74 through which, of course, has already passed any water withdrawn by the pump from pre-rinse water supply tank 57. Pump 52 and sepa rators 65 and 66 continue to operate to circulate water through standpipes 22 and 26 and tanks 20 and 21 and to clean this Water after contamination for as long as necessary and desired for the duration of the pre-rinse cycle. Duplex strainer 74 at which at least some solid soil from lines downstream of the separator may be expected to be stopped is shifted and cleaned from time to time in routine fashion during not only the pre-rinse cycle but also the wash and final rinse cycles. After tanks 20 and 21 have been adequately pre-rinsed, valves 54 and 56 are closed to shut off flow of water to the drain cooler, heater, and standpipes, and valves 149 and 153 are opened. Now as pump 52 and separators 65 and 66 continue to operate, water withdrawn from tanks 20 and Z1 and the return and circulating lines following these tanks is discharged back to pre-rinse water supply tank 57 through lines 148 and 150.

ti After as much. of the pre-rinse circulating water as possible has been restored to tank 57, separators .65

and 66 are shut down,,but pump 52is kept running. Valves 88 and 89'ar'e1.now opened to let the Washdown pump draw fresh water from storage tank 65 through line 87, and discharge it into tank 57 to replenish this tank for any water originally in it that may not have been recovered after. pre-rinse circulation. Once tank 57 has been refilled, pump 52 is shut down, and valves 114,116, 117, 13%, 120, 121, v 123, 149, 153, 53, and 89 are closed. The valves remaining open besides those allowing fiow of steam into and condensate out of heater 34 and drain cooler 44 are valves 72, 73, 143, 46', 46", 35, 3t 31, 33, 167, 198, 1%, 111, 132, 71, 125, 126, and 128.

Next considering the wash cycle, a suitable mixture of fresh water and detergent is made in wash water supply tank 58. To do this, valves 92, 95, 97 and 192 are opened, and transfer pump 63 is started and operated as necessary to inject an appropriate quantity of liquid detergent-into tank 58 from tank 61 through lines 90, 94, 96, and 109; Upon completion of detergent injection to the extent desired, pump 63 is shut down and valves 92, 95, 97, and 152 are closed.

For the next step in the wash cycle operation, the following. valves, starting from wash water supply tank 58,- are opened: 79, 54, 56 (partly if at all), 134, and 135. These valves having been opened, pump 52 is started. The pump withdraws a mixture of fresh water and detergent from wash tank 55 through lines 77, 75, and 70, and circulates it in the same piping path as that previously followed by the plain water in the pre-rinse cycle, except that the circulating mixture flows through bypass line 133 instead of through separators 65 and 66 and their intermediate piping. The same standpipe delivery condition requirements of about 120 F. and 175 p.s.i.g. obtain. Warm streams of water and detergent mixture issuing from the nozzles of the rotating standpipes impinge upon the bulkheads, decks, and overheads of tanks 20 and 21 and wash down fine amounts of liquid and solid contaminants from them. Valve 79 is closed as soon as tank 53 has been substantially emptied by the action of pump 52.

Washdown pump 52 is continued in operation to circulate water and detergent mixture material, and the tank soil not'stopped at strainer 74, through standpipes 22 and 26 and tanks 20 and 21 until the tanks are considered to have been thoroughly washed and/ or the detergent component of the circulating mixture is considered to have been thoroughly spent, both situations desirably obtaining at just about the same time to effectively terminate the wash cycle. After tanks 20 and 21 have been adequately washed, valves 54 and 56 are closed to shut off flow of mixture material; to the drain cooler, heater, and standpipes, and valves 149 and 154 are opened. Now'as pump 52 continues to operate, soiled Water and detergent mixture material withdrawn from tanks 20 and 21 and the return and circulating lines following these tanks is discharged back to wash water supply tank 58 through lines 143 and 151. After as much of the Wash cycle circulating mixture as possible has been restored to tank 58, pump 52 is shut down and valves 149 and 154 are closed. The valves remaining open besides those allowing flow of steam into and condensateout of heater 34 and drain cooler 44 are valves 72, 73, 143, 46', 46", 35, 30, 31, 33, 107, 108, 109, 111, 134, 135, 132, 71, 125, 126, and 128.

As a first step in the final rinse cycle operation, the following valves, startingfrorn final rinse water supply tank 59, are opened: 80, 54, 56 (partly if at all). These valves having been opened, pump 52 is started. The pump withdraws fresh water from final rinse tank 59 through lines 73, 75, and 7t), and circulates it in the same piping path as that previously followed by the water and detergent mixture in the wash cycle, with about F. and 175 p.s.i.g. Warm streams of plain fresh final rinse water issuing from the standpipe nozzles impinge upon the decks, bulkheads, and overheads of tanks 20 and 21, and rinse down'any' residual amounts of soil and detergent remaining on their surfaces. Valve 85 is closed as soon as tank 59 has been substantially emptied by the action of pump 52.

After tanks 20 and 21 have been adequately finally rinsed, valves 54 and 56 are closed to shut'olf flow of final rinse water to the drain cooler, heater, and standpipes, and valves 149 and are opened; Nowas pump 52 continues to operate,.slightly soiled final rinse water withdrawn'from tanks 29 and 21 and the return and circulating lines following these tanks is discharged back to final rinse water supply tank S9'through lines 148 and 152. After as much of the final rinsecycle circulating water as possible has been restored to tank 59, pump 52 is shut down and valves 149'and 155-are closed.

The pre-rinse, wash, and final rinse cycles having been completed, valves 46', 46", 35, 3t); 31, 33,. 157, 108,

159, 111, 134, 135, 132, and 71 are closed. The valves allowing flow of steam into and condensate outof heater 34- and draincooler 44 are closed also. remaining open are valves 72, 73,143, 125,126, and

128. Although no operation'remains to be carried out' on the interior surfaces-of cargo tanks 20 and 21 or any region connected to branch feeder line 33, the liquid' in an at least somewhat emulsified condition due to its detergent component, and this condition must be eliminated before the liquid can be cleaned or purified by mechanical means such as centrifugal separators 65 and 66. To do this, that is, to break the emulsion in tank 58, valves 93, 95, 97, and 102 are opened, and transfer pump 63 is started and operated as necessary to inject an appropriate quantity of liquid de-emulsifier into tank 53 from tank 62 through lines 91,94, 96,and102. Upon completion of de-emulsifier injection to the extent desired, pump 63 is shut down, and valve 102- is closed.

For the next step in cleaning the Water in tank 58, the following valves -areopened: 79, 147, 114, 116, 117, 130,131, 120, 121, 123, and 141. These valves having been opened, Washdown purnp'52'and separators 65 and 66 are started. The pump withdraws water mixed with detergent, de-emulsifier, and some liquid contaminants originally on the interior surfaces of tanks 20 and 21 from tank 58 through lines 77, 75, and 70,'and dis charges it through lines 51, 112, and 113 to the inlet side of centrifugal separator 65. Separators 65 and 66 operating in series effect separations or cleaning ofthe liquid discharged to them from pump 52. Cleaned water leaving separator 66 isdrawn back into tank 58 through lines 129, 138, and 139 by the suction elTect of pump 52. Refuse mixture streams of detergent, de-emulsifier,

and liquid and possibly some solid tank soil flow from the separators through lines 113 and 119, and enter refuse tank 67 through line 122. Pump 68 operates to withdraw liquid material from tank'67 through line 124 and discharge it through line 127 to refuse consumption means in accordance with liquid level signals transmitted by sensing element 128.

Pump 52 and separators 65 and 66 continue to operate to circulate water through tank 53 and to clean this water for as long as necessary and desired; that is, until the body of water in tank 58 at any given time appears to be in substantially clean condition. When this condition is achieved, pump 52 and separators 65 and 66 are shut down, and valves 79 and 141 are closed.

The liquid material in final rinse water supply tank The valves 59 is probably in an at least slightly emulsified condition due to a detergent component. To eliminate this condition, valve 103 is opened, and transfer pump 63 is started and operated as necessary to inject an appropriate quantity of de-emulsifier into tank 59 from tank 62 through lines 91, 94, 96, and 101. Upon completion of die-emulsifier injection, pump 63 is then shut down, and valves 93, 95, 97, and 103 are closed. Next, valves 80 and 137 are opened and washdown pump 52 and separators 65 and 66 are started. The pump with draws liquid material from tank 59 through lines 78, 75, and 7t), and discharges it through lines 51, 112, and 113 to the inlet side of separator 65. After flowing through separator 65, line 115, and separator 66, water is returned to tank 59 through line 129.

Pump 52 and separators 65 and 66 continue to operate to circulate water through final rinse water supply tank 59 and reject liquid refuse to contaminated oil tank 67 for as long as necessary and desired; that is, until the body of water in tank 59 at any given time appears to be in substantially clean condition. When this condition is achieved, separators 65 and 66 are shut down, and valves 80, 72, 147, 114, 116, 117, 130, 131, 137, 120, 121, and 123 are closed. The valves remaining open are valves 73, 143, 125, 126, and 128, and washdown pump 52 is continued in operation.

Some of the water originally in tanks 53 and 59 may not have been recovered in them after the wash and final rinse cycles and the water cleaning operations just described, with the result that these tanks should be replenished or topped 011' with fresh water from storage tank 60. Accordingly valves 88, 89, 149, and 154 are opened and the still-operating pump 52 draws water from tank 60 through lines 87 and 70 and discharges it into tank 58 through lines 148 and 151. Once tank 58 has been refilled, valve 154 is closed and valve 155 is opened. Pump 52 now discharges water from tank 60 into tank 59 through lines 148 and 152. Once tank 59 has been refilled, pump 52 is shut down, and valves 88, 89, 73, 143, 149, and 155 are closed. Valves 125, 126, and 128 may be closed also. The body of fresh water in storage tank 60 will have become somewhat depleted in the course of replenishing the water supply in tanks 57, 58, and 59 and should be restored by the admission of fresh water to tank 60 through either line 81 or line 85.

In the course of the description so far, no mention has been made of line 140 leading into pre-rinse water supply tank 57 and valve 142 in this line other than to identify them. This line and valve, although not subject to great use, are desirably installed to allow circulation of water through tank 57 without this water having to be sent through standpipes 22 and 26 and cargo tanks and 21.

From time to time it may be desirable to pump the water in tanks 57, 58 and 59 overboard either to obtain access to the interior of these tanks for work or inspection, or to simply lighten the ship of the weight of water which is associated with them when they are full. To effect this emptying, valves 157 and 158 in overboard discharge line 146 are opened, and so are valves 76, 79, 80, 72, 73 and 143, and pump 52 is started. The pump withdraws water from the pro-rinse, wash, and final rinse water supply tanks, and discharges it overboard through line 146.

The detergent solution or detergent and fresh water mixture as made up in wash water supply tank 58 is contemplated to be of sufiicient strength at the beginning to wash all of the ships tanks in at least one program of washing so that there will not have to be any addition of detergent during the program, or, at most, only enough to replenish or make good the loss associated with washing liquid left in the various tanks or tank bays if washing is done by groups of tanks or tank bays.

It is within the contemplation of the present invention that wash and final rinse water supply tanks 58 and 59 each be divided into two parts. This arrangement, re-

10 quiring the use of emergency pump 156 and some additional piping and valves, would allow a portion of the washing solution and a portion of the final rinse water to be cleaned while another portion of each was workmg.

The starting data and time and the length of each cycle for the cleaning of each tank and an indication of unspent detergent should be logged in by a Data Logger. A sensing element for indication of unspent detergent can be installed in wash water supply tank 58.

Referring next to FIGS. 2 and 3, a typical tank vessel or oil tanker of which the structure includes main deck plating 159, bottom plating 160, upper longitudinals 161 and 162, bottom longitudinals 163 and 164, deck stiffeners 165, 166, and 167, and bottom stiffeners 168, 169, and has a tank bay 171 defined in it within which there is installed a typical standpipe 172 according to the present invention, this standpipe being similar to standpipes 22 and 26 already described generally as components of the tank washing system shown in FIG. 1.

tandpipe 172 comprises pipe sections 173, 174, 175, 176, 177, and 178 joined by bolts at gasketed mating flanges. The pipe section assembly is surmounted by upper bearing assembly 179, and rests upon lower bearing assembly 180. Lower bearing assembly 180 and indeed the whole assembly of standpipe 172 is supported and provided with bottom alignment on and by foundation elements 181, 182, and 183 which tie in to botom longitudinals 163 and 164 and bottom stiffener 169. A flanged connection is made to upper bearing assembly 179 on its upper end by pipe elbow 184 at the outlet end of liquid supply pipe or branch line 185. Top alignment of the standpipe assembly is provided by bracket elements 186 and 187 which tie in to upper longitudinals 161 and 162 and pipe elbow 184. Bracket element 187 is attached to bracket element 186 in a slip joint so that movement of deck plating 159 and bottom plating 160 due to working of the ship in a sea and lengthening and shortening of standpipe 172 due to temperature changes can be accommodated without placing undue columnar stress upon the standpipe.

Centrally standpipe 172 is aligned laterally by bracket 188 and strap 189. Bracket 188 extends between and is supported at its ends by transverse web frames 190 and 191 shown in FIG. 4. At about its mid-length, the bracket is formed with a half-round depression or offset to receive pipe section 175, and strap 189 bolted to bracket 188 is formed similarly. The half-round regions of the bracket and strap, therefore, together assume the nature of a sleeve bearing in which the standpipe may be rotated.

Pipe section 173 which is rotatably fitted for part of its length within upper bearing assembly 179 carries rotater nozzle assemblies 192 and 193. Similarly, pipe section 178 carries rotator nozzle assemblies 194 and 195. The four rotator nozzle assemblies are also oriented with respect to the assembled standpipe that the reactive forces of liquid jets issuing from them are additive to produce a moment on the standpipe tending to rotate it about a vertical axis. At water supply pressures of about 175 p.s.i.g. it is contemplated that standpipe 172 will turn at about 35 r.p.m. under the influence of the rotator nozzles. The jet streams of plain water and water and detergent mixture discharged from these nozzles or nozzle assemblies may have some effect to prerinse, wash, and finally rinse some of the interior surfaces of tank bay 171 as well as to proxide rotation of the standpipe. In practice, however, other nozzles to be described are relied upon primarily to achieve washing and rinsing eifects.

Washing nozzle sets or assemblies 196, 197, 198, 199, 200, 201, 202, and 203 are carried in pairs by pipe sections 174, 175, 176, and 177. Each washing nozzle assembly is independently rotatable with respect to the pipe section on which it is mounted, and each one has two oppositely aimed nozzle outlet openings which'are linearly offset on Opposite sides of the assemblys pivot axis, so that the reactive forces of liquid jets issuing from the assemblyare' additive to produce a' moment upon it tending to rotate it about a horizontal axis normal to the standpipe. At water supply pressuresof about 175 p;s.i.g. it is contemplated that the washing nozzle assemblies will turn at about 35' rpm. with respect to the pipe'sections on which they are mounted. Actually, of course, the motion of the nozzle elements of any washing nozzle assembly will be a compound motion consisting of the assemblys rotary motion about a horizontal axis and the standpipes rotation about a vertical axis. Such compound motion insures that in the course of a reasonably extended pre-rinse, wash, or final rinse cycle operation all of the interior surfaces of tank bay 171 will be struck by jets of freshwater or water and detergent mixture issuing from the washing nozzle assemblies.

' Referring next to FIGS. 4 and 5, and-considering upper bearing assembly 179 particularly, 204 is a bearing housing to which the-flange of pipe elbow Hal-makes bolted attachment across gasket 205, and which is open at its upper end in alignment with the pipe elbow bore; 2% is an O-ring seal between housing 204 and the slightly enlarged upper end of pipe section 173 which has a turning fit within a shoulder in the housing; 207 and 2% are ball bearing sets having their inner races fitted on pipe section 173 and their outer races fitted within housing 204; 239 is a split retaining ring aflixed in a groove to pipe section 173; 210 is a cover plate bolted to housing 264 across gasket 211 and through which pipe section 173 passes with a turning fit, and 212 is an O-ring seal between cover plate 210 and pipe section 173.

Now considering particularly lower bearing assembly 180 in FIG. 4, 213 is a bearing housing to which the flange on the upper end of foundation element 183 makes bolted attachment across gasket 214; 215 and 216 are ball bearing sets having their inner races fitted on the slightly enlarged lower end of pipe section 178 and their outer races fitted within housing 213; 217 is a split retaining ring affixed in a groove to pipe section 173; 218 is a cover plate bolted to housing 213 across gasket 219 and through which pipe section 178 passes with a turning fit, and 220 is an O-ring seal between cover plate 218 and pipe section-173.

Fresh water or a Water and detergent mixture pumped into standpipe 172 through branch line 185 and pipe elbow 184 passes down through and into upper bearing assembly housing 204- and pipe sections'173, 174, 175,176,

177, and 178 to transverse bafile or partition 221 in the last section, and outwardly from these sections through the several nozzle assemblies which 'are in fluid flow connection with them. Details of the connections of rotator nozzle assemblies 192 and 193 to pipe section 173 and assemblies 194 and 195 to pipe section 178 are shown in FIGS. 4 and 5; considered in association with FIG. 3. In numericalorder the rotator nozzle assemblies comprise curved conduit portions 222,223, 224, 225 welded around opposite, appropriately vertically located lateral openings in pipe sections 173 and 178; Rotator nozzle assemblies 192, 193, 194, and 195 further comprise'nozzle elements 226, 227, 228, and 229 respectively which are in threaded engagement with the curved conduit portions of the assemblies asshown particularly in FIG. 5 wherein also the reactive rotation of thestandpipe is indicated.

Referring finally to FIGS. 6 and'7, washing nozzle as semblies 198 and-199 which'may be considered typical of all of the washing'nozzle assemblies respectively comprise T-shaped spinner members 230 and 231 on the ends of the internally vaned arms or bar portions of which there are respectively nozzle elements 232 and 233, and234'and 235. Each 'nozzle element is in threaded engagement with the spinner member with which it is associated. The stem portions of spinner members 23% and 231 extend into and are rotatably retained within washing nozzle bearing'assem'blies 236 and 237 respectively, these assemblies being retained in place on pipe section and constructed as will be described.

Two straight conduit portions 238 and 239 are welded around opposite, appropriately vertically located openings in pipe section 175, and have flanges at their outer ends. At these flanges they make bolted connections across gaskets such as gasket 240 to housings 241 and 242 of washing nozzle bearings assemblies 236 and 237. These housings are open at their inner ends in alignment with the bores of conduit portions 238 and 239.

Particularly considering bearing assembly 237, 24 3 is an O-ring seal between housing 242 and the inner end of the stern portion of spinner member 231 which has a turning fit within a shoulder in the housing; 244 and'245 are ball bearing sets having their inner races fitted on the stem portion of spinner member 231 and their outer races fitted within housing 242; 246 is a split retaining ring'affixed in a groove to the spinner member stem portion, and 247 is a friction ring surrounding retaining ring 246; 248 is a friction ring fitted within the bearing housing against which ring 247 rubs to limit the speed of rotation of nozzle assembly 199; 249 is a cover plate bolted to housing 242 across gasket 251 and through which the spinner member stem portion passes with a turning fit, and 251 is an O-ring seal between cover plate 249 and the stem portion of the spinner member of washing nozzle assembly 199.

Water or water and detergent mixture flows outwardly from pipe section 175 through conduit portions 238 and 239, through bearing housings 241 and 242, through the stem and bar portions of spinner members 231) and 231, and finally out of nozzle elements 232, 233, 234, and 235 and reactively imparts rotation to the washing nozzle assemblies as is shown, for example, in the case of assembly 199 in FIG. 7. In place of friction rings 248 and 247, it is contemplated that an internally toothed ring gear may be installed within bearing housing 242 and a meshing pinion mounted rotatably on the stem portion of spinner member 231 of washing nozzle assembly 199 as speed limiting means. Similar means could, of course, be used on other washing nozzle assemblies as well.

Although this invention has been described with some degree of particularity, it is to be understood that resort may be had to at least some changes in the details of construction of its illustrated apparatus embodiments without departing from the spirit and scope of the invention. It is to be understood especially that this invention is not limited to the washing of tanks aboard ships nor even to the washing of tanks forming parts of the structures or superstructures of bulk liquid transporters generally such as, for example, highway tank trucks and railway tank cars in addition to water-borne tankers. Specifically it is to be understood that the present invention is well adapted for the washing of permanently installed, land based tanks with the inventive equipment itself as generally illustrated diagrammatically in FIG. 1, includingthe standpipe or standpipes, being of a portable nature.

The present invention is especially valuable, however, as a system for Washing the cargo liquid tanks of a marine bulk transporter of liquids, particularly when used in connection with a suitable gas freeing system to obtain certification that the tanks are both clean and gas free. Such certification is important because it must be obtained before any cargo liquid which is more highly refined than a previously carried cargo liquid can be put into the tanks, or any repair work done in the tanks. Obtaining of this certification is expensive and time consuming whentraditional methods of tank Washing or cleaning are employed, since each tank must be opened and inspected visually for cleanliness at the end of some preselected period of treatment according to the initially described system of the prior art, for example. A positive indication of when the tanks are clean is inherently available through the use of the system of the present invention because of the systems amenability to data logging, continuous examination of the water circulated in the various operating cycles, and determination of unspent detergent.

It is intended to secure protection by Letters Patent of this invention in all its aspects as the same are set forth in the appended claims to the broadest extent that the prior art allows.

What is claimed is:

1. An apparatus for washing the interior surfaces of tanks, said apparatus comprising (1) a standpipe adapted to be mounted in bearings Within a tank to be washed so as to permit rotation of said standpipe about its own longitudinal axis, (2) rotatable joint means at one end of said standpipe wherethrough fluid may be supplied under pressure to the interior of said standpipe, (3) first and second nozzle assemblies fixedly connected to the exterior of said standpipe near one end, on opposite sides, and in fluid flow communication with the interior thereof, and each having its outlet axis lying in a plane substantially perpendicular to the longitudinal axis of said standpipe and in non-intersecting relation with said axis, and said first and second nozzle assemblies being oppositely directed so that the moments of jet reaction forces of fluid issuing from them tending to rotate the standpipe are additive, and (4) third and fourth nozzle assemblies rotatably connected to the exterior of said standpipe at an intermediate length position, on opposite sides, and in fluid flow communication with the interior thereof, said third and fourth nozzle assemblies being disposed -to rotate in planes substantially parallel to the longitudinal axis of said standpipe, and each having its outlet axis lying in its plane of rotation in non-intersecting relation with its axis of rotation.

2. An apparatus for washing the interior surfaces of 14 tanks according to claim 1 in which said third and fourth nozzle assemblies each comprise a pair of oppositely directed nozzle members having their outlet axis offset on opposite sides of the axis of rotation of the assembly to which they belong.

3. An apparatus for washing the interior surfaces of tanks according to claim 1 which further includes fifth and sixth nozzle assemblies similar to said first and second nozzle assemblies, said fifth and sixth nozzle assemblies being located near the opposite end of said standpipe from said first and second nozzle assemblies, and being so directed that the moments of jet reaction forces of fluid issuing from them tending to rotate said standpipe are additive to each other and to those of fluid issuing from said first and second nozzle assemblies.

4. An apparatus for washing the interior surfaces of tanks according to claim 1 which further includes a plurality of pairs of nozzle assemblies similar to said paired third and fourth nozzle assemblies and including the same substantially evenly distributed along the length of said standpipe.

5. An apparatus for washing the interior surfaces of tanks according to claim 1 which further includes rotational speed limiting means for said third and fourth nozzle assemblies.

References Cited in the file of this patent UNITED STATES PATENTS 1,545,896 Hanlon July 14, 1925 1,806,740 Butterworth May 26, 1931 2,933,093 Handside Apr. 19, 1960 3,001,534 Grant Sept. 26, 1961 FOREIGN PATENTS 750,784 Great Britain June 20 1956 UNITED STATESaBATENT OFFICE CERTIFICATE 10F CORRECTION Patent No, 3 140,828 July 14, 1964 Thomas Galanor It is hereby oertified tnet erroxfw'flppears in the above numbered patent requiring correction 'and thatfibhegsei d Letters Patent should read as corrected below. l

Column 2 line 4 for "move" read moved column 3) line 2O for figures read Figures a column l line 8 for "de-mulsifier" read de-emulsifier column 10, line 6, for "data" read --*=-date line 56 for "also" read all so column 14, line 3, for "axis" read axes line 32, for "Hand side" read Handyside line 36 for "June 20 1956 read June 20 l956---. 7

Signed and sealed this l-7th d ay of November 1964.

(SEAL) At'test:

EDWARD J. BRENNER Commissioner of Patents ERNEST W. SWIDER Attesting Officer

Claims (1)

1. AN APPARATUS FOR WASHING THE INTERIOR SURFACES OF TANKS, SAID APPARATUS COMPRISING (1) A STANDPIPE ADAPTED TO BE MOUNTED IN BEARINGS WITHIN A TANK TO BE WASHED SO AS TO PERMIT ROTATION OF SAID STANDPIPE ABOUT ITS OWN LONGITUDINAL AXIS, (2) ROTATABLE JOINT MEANS AT ONE END OF SAID STANDPIPE WHERETHROUGH FLUID MAY BE SUPPLIED UNDER PRESSURE TO THE INTERIOR OF SAID STANDPIPE, (3) FIRST AND SECOND NOZZLE ASSEMBLIES FIXEDLY CONNECTED TO THE EXTERIOR OF SAID STANDPIPE NEAR ONE END, ON OPPOSITE SIDES, AND IN FLUID FLOW COMMUNICATION WITH THE INTERIOR THEREOF, AND EACH HAVING ITS OUTLET AXIS LYING IN A PLANE SUBSTANTIALLY PERPENDICULAR TO THE LONGITUDINAL AXIS OF SAID STANDPIPE AND IN NON-INTERSECTING RELATION WITH SAID AXIS, AND SAID FIRST AND SECOND NOZZLE ASSEMBLIES BEING OPPOSITELY DIRECTED SO THAT THE MOMENTS OF JET REACTION FORCES OF FLUID ISSUING FROM THEM TENDING TO ROTATE THE STANDPIPE ARE ADDITIVE, AND (4) THIRD AND FOURTH NOZZLE ASSEMBLIES ROTATABLY CONNECTED TO THE EXTERIOR OF SAID STANDPIPE AT AN INTERMEDIATE LENGTH POSITION, ON OPPOSITE SIDES, AND IN FLUID FLOW COMMUNICATION WITH THE INTERIOR THEREOF, SAID THIRD AND FOURTH NOZZLE ASSEMBLIES BEING DISPOSED TO ROTATE IN PLANES SUBSTANTIALLY PARALLEL TO THE LONGITUDINAL AXIS OF SAID STANDPIPE, AND EACH HAVING ITS OUTLET AXIS LYING IN ITS PLANE OF ROTATION IN NON-INTERSECTING RELATION WITH ITS AXIS OF ROTATION.

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