US2643023A - Hose drain for floating roof tanks - Google Patents

Description

June 23, 1953 F. mMoYEr-z 2,643,023

` .zHQSEmAm FOR FrzoAINc ROOFI mmm Filed nay 19,4 1951A 2 shmss'heet A1 @ne 23, 1953l F, D, MQYER v2,643,023

A HOSE DRAIN FOR FLOATING ROOF TANKS Filed May 19, 1951 2 Sheets-Sheet 2 Patented June 23, 1953 HOSE DRAIN FOR FLOATING ROOF TANKS Frederick D. Moyer, Chicago, Ill., assigner to Chicago Bridge & of Illinois Iron Company, a corporation Application May 19, 1951, Serial No. 227,189

9 Claims.

This invention relates to a drain for a floating roof tank and more particularly to a drain utilizing a flexible hose for its entire length which may permit the floating roof to rest on the tank bottom when in its lowermost position.

It has been recognized as desirable to build and therafter land floating roofs in liquid storage tanks on the bottom of the tank. Ordinarily a number of roof supports extend below the roof proper and maintain the roof several feet above the bottom of the tank even when the tank is empty. Floating roofs have not previously been made to land on the tank bottom for a number of reasons including the necessary provision under the roof for a draining structure. The drain of this invention permits the roof to rest on the bottom of the tank when the tank is empty and also permits ready inspection and replacement of the drain at any time. The drain also permits the fioating roof to be constructed directly on the bottom of the tank, thereby reducing the cost of the tank by virtue of the elimination of temporary supports and construction framing.

The invention will be described with relation to an exemplary embodiment thereof illustrated in the accompanying drawings. Of the drawings, Fig. 1 is a vertical sectional view through a floating roof tank showing the drainage means of this invention incorporated therein; Fig.A 2 is a fragmentary plan view of the tank illustrated in Fig. l; Fig. 3 is a sectional View taken as indicated by line 3 3 in Fig. 2; and Fig. 4 is a sectional view taken as indicated by line 4-4 in Fig.3.

There is illustrated in Fig. 1 a liquid storage tank having Vside walls I joined to a bottom ll which rests directly upon a prepared grade I2. A floating roof I3 having an outer annular pontoon I 4 and a central sump I5 is shown iloating within the storage tank upon liquid I6. Since the drain of this invention pere mits the iloating roof I3 to be constructed directly upon the bottom Il of the tank, the bottom is shaped to conform to the configuration of the bottom deck I I of the floating roof I3. Thus the plates, pontoons, and other structural members which go to make up the floating roof may be laid out directly on the bottom of the tank during construction. A depressed portion I8 is also provided in the bottom for the reception of the sump I centrally located in the floating roof. Ordinarily an annular space I9 is provided about the oating roof between the rim of the roof and the tank shell so that the 2 roof will have clearance for vertical movement within the shell, This space may be sealed so as to prevent loss or contamination of the tank contents by any means desirable (not shown).

The floating roof is provided with an upper deck which is sloped in such a .way as to direct all precipitation to the central sump I5 from which it must be removed. The drain used to remove the precipitation from the sump is a exible hose 25 whichextends through a metal e1- bow fitting 26 secured to the bottom II of the tank and is connected therewith at a ange 21. A suitable pipe 28 is also connected to the tting 26 at the flange 2l for conducting the liquid away from the tank site. A bleed line 29 provided with a valve 30 communicates with the interior of the iitting 26 so that accumulated water on the bottom of the tank may be drained from the fitting.

In order that the hose drain 25 will not interfere with the landing of the roof on the bottom of the tank, the hose passes from the drain outlet tting 26 substantially vertically to an idler sheave SI mounted within a compartment in the outer` pontoon I 4 of the roof. From the sheave 3| the hose passes over the top of the roof to a drum 32 mounted near the center1 of the roof. As best seen in Fig. 4, the upper end 25 of the hose is secured to the end of a metal tube 33 which communicates with the hollow shaft 34 Asupporting the drum 32. It is intended that the hose 25 may be reeled upon the portion 36 of the drum as the roof rises and falls to maintain only a sufficient uncoiled length of hose to extend from the drum to the outlet fitting 26.

The hollow shaft 34 of the drum is supported in tubular bearings 3l and 3B, in turn supported by standards 39 and lo mounted on the deck of the roof. AOne end of the shaft 34 is blanked ofi at 4I and the other end 42 communicates with a hose 43 extending to a pump 46 whose suction inlet 4l extends into the sump I5. By blanking off one end of the shaft 34, a single stuffing box 48 is required.

The means herein utilized to feed the hose about the drum 32 comprises a cable 5D having its upper end-5I Vsecured above the top of the tank shell upon a framework 52.v The cable passes downwardly to the roof and about an idler sheave 53 mounted on the outer pontoon lll of the roof. The lower end of the cable is secured to the drum to wind about the surface thereof in the space 54. The cable is wound about the drum in a direction opposite to the direction that the hose is wound about the drum so that the drum is caused to'rotate whenever the roof moves within -3 the tank in a vertical direction. If desired, an electrical conduit may be brought into the motor 55 for operating the pump 43 along with the cable 5D. A double sheave may be provided at 53 to accommodate the conduit.

The operation of the hose drain is positive and simple and requires no power means other than that to pump the water from the sump into the hose drain. As the roof rises from the bottom of the tank, the hose pulls on the drum 32 to rotate it and unwind therefrom, thus causing the cable 59 to be wound upon the drum. 'Ihe drum is mounted in bearings which permit it to be easily rotated, putting little strain on the hose itself. As the roof descends within the tank, the cable causes the drain to rotate, thus reeling in the hose 25. Both the hose 25 and cable `El) are taut without substantial stress so that slight movement of the roof will cause rotation of the drum as above described. It will be noted that during the travel of the roof between the bottom and top of the tank, substantially all of the hose drain is accessible from the rocf for inspection and the like. rIhe hose may be replaced at any time while the tank is in service by detaching it from the drum and the flange 2l ron the outlet fitting and pulling the hose through the fitting 26. The new hose is attached to the upper end 25 of the old hose so as to pull it into position at the same time that the old hose is removed from the tank.

The specific arrangement of the sheaves 3i and 53 herein shown is at diagrammatically opposite points on the roof and the drum and pump are generally at the center of the roof to provide for balancing of the weights on the roof. However, it will be understood that in installations where the distribution of the weight is unimportant the drum 32 may be placed in any other location desired. In some installations the sheave 3l may be eliminated and a cable and drain hose wound directly onto the drum 32 located adjacent the periphery of the roof. Also housings such as the housing Sii over the sheave 3i may be provided over all of the otherwise exposed parts of the drainage system, if desired.

While I have shown and described certain ernbodiments of my invention, it is to be understood that it is capable of many modications.

Changes, therefore, in the construction and arrangement may be made without departing from the spirit and scope of the invention as disclosed in the appended claims.

I claim:

l. In a storage tank having a oating roof, drainage means for the roof comprising, a drain hose extending between the roof and the tank bottom, a drum rotatably mounted on the roof, the upper portion of said hose being secured to said drum for reeling thereon and the lower end being connected to a drain outlet in the bottom of the tank, means for conducting liquid from the top side of the roof to said `drain hose and means for rotating said drum with vertical movement of the roof to maintain said drain hose substantially taut between the tank bottom and the drum.

2. Drainage means as specified in claim l in which the drum is mounted on the roof above the bottom thereof and said drain hose extends substantially vertically between the roof and the tank bottom and through an opening in the roof to permit the roof to rest on the bottom of the tank in its lowermost position.

3. Drainage means as specied in claim 1 in which a cable extends between the roof and the top of the tank shell with the lower portion of said cable being secured to said drum for reeling thereon and the upper end thereof being secured to the tank, said cable and drain hose being oppositely wound on said drum and substantiallytaut to feed about the drum with vertical movement of the roof. l,

`fi. In a liquid storage tank having a floating roof adapted to rest directly on Athe tank bottom in its lowermost position, drainage means for the roof comprising, a rotatable drum mounted on the roof, a hose drain having its upper portion wound in one direction about the drum, an intermediate portion passing through the roof and its lower end connected to a drain outlet in the bottom of the tank, said hose extending substantially vertically from said outlet to the roof, means for conducting liquid on the roof to said drain hose, a cable having its upper end secured to the top of the tank and its lower portion wound in an opposite direction about the drum, said drain hose and cable being taut whereby rise and fall of the roof feeds said hose and cable about the drum and coils a major portion of the hose on said drum when the roof is resting on the tank bottom.

5. In a liquid storage tank having a floating roof, drainage means for the roof comprising, a flexible drain hose extending substantially vertically between the roof and the tank bottom, a drum rotatably mounted on the upper side of the roof, the upper end of said hose being secured to the drum for reeling the hose upon the drum and the lower end being connected to a drain outlet in the bottom of the tank, said roof having an opening for the hose to pass therethrough, means for conducting liquid from the top side of the deck to said drain hose and cable means extending substantially vertically between the top of the tank and the roof with the upper end of said cable-means being secured to the tank and the lower end being secured to the drum for reeling the cable means thereon, said cable means and drain hose being oppositely wound on the drum and each being substantially taut between its secured ends whereby the drain hose is reeled on and off the drum with vertical movement of the roof to maintain an uncoiled length of hose sufficient only to extend from the drum to the drain outlet.

6. Drainage means as specied in claim 5, in which the drum is located at substantially the center of the roof and said drain hose passes from the drum over a sheave adjacent the periphery of the roof and then vertically to the tank bottom, said sheave being mounted in the upper portion of the roof to maintain the portion of the hose between the sheave and drum accessible from the top side of the roof.

'7. Drainage means as specified in claim 5, in which the floating roof has a central sump and said drum is mounted on the roof adjacent the sump, said hose and cable means each passing over a sheave mounted on the roof adjacent the periphery thereof.

8. In a liquid storage tank having a floatin roof, drainage means for the roof comprising, a flexible drain hose having its lower end connected with a drain outlet in the bottom of the tank, a sheave rotatably mounted on the roof directly above said drain outlet, a drum rotatably mounted on the upper side of the roof adjacent the center thereof, said drain hose extending over said sheave and through the roof and being connected to said drum for reeling thereon, pump means for conducting liquid from the top side of the roof to said hose, and means for rotating said drum upon vertical movement of the roof to keep the drain hose substantially taut including, a cable secured to the top of the tank shell and extending substantially vertically to the peripheral portion of the roof and then inwardly to said drum, said cable being wound about the drum oppositely to the Winding of the hose on the drum and being taut between the tank shell connection and the drum to reel in the hose upon downward movement of the roof within the tank.

10 Number 5 balance the weight thereof on the roof.

FREDERICK D. MOYER.

References cited 1n the me of this patent UNITED STATES PATENTS Name Date 1,665,163 Gallagher Apr, 3, 1928` 1,668,792 Wiggins May 8, 1928 2,538,878 Laird Jan. 23, 1951

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