US2663453A - Floating roof for sewage digesting apparatus - Google Patents

Description

Dec. 22, 1953 J. H. WIGGINS ET AL 2,663,453

FLOATING ROOF FOR SEWAGE DIGESTING APPARATUS Filed Aug. 31, 1950 l N VEA/ TORS JOHN H W/asuvs JOHN W ALLEN ATTORNEY.

Patented Dec. 22, 1953 FLOATING ROOF FOR SEWAGE DIGESTING APPARATUS John H. Wiggins and John W. Allen, Chicago, 111.; said Allen assignor to said Wiggins Application August 31, 1950, Serial No. 182,444

4 Claims.

This application is a continuation-in-part of our joint application for patent Serial No. 123,762, filed October 26, 1949, for Sewage Digesting Apparatus, which resulted in U. S. Patent 2,605,014, dated July 29, 1952.

Our said application discloses a sewage digesting apparatus, whose floating cover comprises a gas collecting chamber, a flexible deck portion extending radially from said gas collecting chamber, and an annular-shaped load member formed from a relatively heavy, moldable material attached to the peripheral edge of said flexible deck portion so as to maintain same in such a position as to induce the flow of gases on the underside of said cover, into said gas collecting chamber.

The main object of our present invention is to reduce the amount of metal used in the peripheral portion of a floating cover for sewage disposal apparatus, that embodies the basic idea of the floating cover disclosed in our above men tioned ending application for patent.

Another object is to reduce the cost and simplify the operation of building such a floating cover.

The figure of the drawing is a fragmentary, vertical, transverse sectional view of a floating cover embodying one form of our present invention.

In the drawings, the reference character A designates the side Wall of the tank of the apparatus that holds the sewage or other liquid being processed, B designates the gas collecting chamber at the center of the floating cover that is adapted to receive gases evolved from the sewage, C designates the flexible deck portion of the cover that extends radially from said gas collecting chamber, and D designates the annularshaped load member, made of concrete or other moldable material, that is attached to the periphery of said deck portion C, so as to maintain the same in an inclined position, sloping upwardly from its outer edge towards the center of the cover, and thus induce a flow of gases on the underside of the cover into the gas collecting chamber B. In such a structure part of the weight of the load member I) is supported by its own submersion in the liquid on which the cover floats, and the remainder of the weight of the load member is supported by extra submersion of the deck portion C. Said deck portion would normally sink in the liquid only as much as required by its own weight. However, the load member causes said deck portion to sink an extra amount. It is this extra submersion above referred to.

In the form of our invention herein illustrated which is particularly adapted for use in tanks of relatively great diameter, the central portion of the cover is formed by a rigid, circular pontoon E? of any preferred construction, rovided with an annular rim i, to the lower edge of which the flexible deck portion C is rigidly attached. The gas collecting chamber B is formed by a vertically-disposed, tubular member 2 at the center of the pontoon E, closed at its upper end by a gas-tight closure 3 and having its lower end open, so as to permit the gases on the underside of the cover to flow freely into the gas collecting chamber. Gases are conducted from the chamber B to the atmosphere, or to a point where they are used, by an eduction pipe 4 leading away from said chamber. At the outer edge of the deck portion C there is a single relatively high or deep, annular, steel rim F, which is connected to the lateral edge of said deck portion by a liquidtight joint, said rim being provided at' its upper end with a flange 5. In addition to imparting stiifness to the peripheral portion of the cover, said rim supports or carries the load member D and co-acts with same to produce a rigid, annular girder of relatively great weight, that is attached to the peripheral edge of the flexible deck portion C, and said rim F also effectively prevents any liquid in the tank from getting onto the top side of said deck portion. Preferably, said load member is cast or molded in situ around the outer side of the rim F and is permanently attached to same by devices on the exterior of said rim that are embedded in the concrete or other similar material of which the load member is constructed, during the operation of casting or molding said member. Thus, as shown in Figure 1, the rim F can be provided with anchoring devices 6 that are embedded in the side face of the load member contacted by the rim, and can also be provided with radially-disposed ties or hangers extending downwardly and outwardly from the upper end portion of the rim and embedded in the top surface of the load member, said ties or hangers '2 taking up tension or compression stresses to which the load member is subjected, in addition to functioning as tie bars between the flanged upper portion of the rim F and. the peripheral portion of the load member D. In casting or shaping the load member, the rim F constitutes one side wall of the form into which the concrete is poured, and the bottom and other side wall of said form are constructed in the usual manner from lumber or removable form sections that are dismantled after the concrete has set. By constructing the peripheral portion of the floating cover in the manner above described, we effect a considerable saving in steel, as only a single annular steel member, to wit, the rim F, is combined with the molded or cast load member D.

When the cover is not floating on the sewage or other liquid-aim the tank of'the. apparatus, as shown in dotted lines, any suitable-means may be used to support said cover. We have herein illustrated a supporting means for the centrali portion of the cover consistingoiasupporting structure G located at the center ofthe and resting on the bottom of same, and a supporting means for the peripheralzportiorrzofathe cover, composed of chains 8 fastened tmthe upper end of the side wall A of the tank.and attached to.

the load member D by bars or rods Hat'the lower ends of said chains embedded in the load member...

Rain water or the like that collects on the top sideof-the deck portion-C can be conducted away from same-invarious ways, as; for example,- by one or'more :drains i (i, as. shown in thedraw ing .1-

Having thus described our. invention, what we claim and I desire to. secure by- Letters Patent. is:

1. An apparatus; comprising a tank. that is adapted tohold a liquidor-liquid-likeasubstance that 'isbeing'stored or processed,: a floating cover for said tank comprising a I gas collecting; chame ber' at approximately the center of said cover having provision for permitting gases on theundersideof the-cover to-flow-i-nto said'chamber, a. flexible deck portion.- extending radially from saidgascollecting chamber, a single, annularshaped: metal rim. projecting: upwardly at the peripheryiofsaiddeck portion and joined to the peripheral edger-10f sameby a'liquid-tight joint; andan' annular-shaped load member constructed of concreteorthe like, cast'or-moldedin situon the outer. face of: said and: interlocked with same: so as: to maintainsaid deck portion an inclined position-1 sloping:v upwardly; and inwardly towards thecenterof thereof, .saidlload member being:v located outside of. or beyond said. rim, whereby 'partof the weight of said:load.:member is supportedby'its own-submersion in th'e'liquid on which the-cover floats.

2; An apparatus, comprising; atank that is adapted to hold a liquid or liquid-dike substance that is'being stored'onprocessed, ,a floating. ;cover for said tank comprising agas-colleetingichamber at approximatelyythecenter of saidcover'. having provision for permitting. gases on the underside of the-cover to flow into said chamber, a'flexible deck portion extending radially from said gas collecting chamber, an annular-shaped metal rim projecting upwardly from the peripheral edge of said deck portion, and an annular-shaped load member, constructed of concrete or the like, attached to the outer side of said rim so as to maintainsaid deck portion inzsuchar position as to induce the flow of gases on-the underside of the deck portion into said gas collecting chamber, said load mbember being located outside of or beyond said rim, whereby part of the weight of saidload member'is supported by its own submersion in the liquid on which the cover floats.

3 An; apparatus; comprising a tank that is adaptedito-hoid a liquid or liquid-like substance that is being stored or processed, a floating cover for 'saidtank'comprising a gas collecting chamber atrapp'roximately the center of said cover having provision for permitting gases on the underside of theucover. to. flowiinto said chamber, -a flexible deokportion extending radially from said gas collectingchamber, an annular-shapedmetalrim projectingupwardly. from the peripheral edge. of said deck portion,.and'a 1oad..member of conic rete. or. thalike. combined with. said.rim,..for maintaining said deck portion inan inclinediposition sloping upwardly. and. inwardly towards the center of the rooflfsaidload member being dis posed'in such relationshipv with said rim tliatlpart of the weight .of said load'memberis supportedby its own submersion. in.the.liquid on which. the cover floats.

4. An apparatus of the .kinddscribed in claim 3,.which includesinclined tie members. extend; ing downwardly and'outwardly 'fromtheupper end portion of. said. rim and having their. lower end portions embedded-in said load member;

JOHN'H. WIGGINS. JOHN W? ALLEN,

References" Cited in? the file of this" patent UNITED STATES PATEN'IS-v Number Name Date 1,717,100 Downes June 11, 1&29 1,919,634' Hauptcta-L l July- 25,- 1933 2,129,266 Fisher et a1: Sept 6; 1938 2 ,201,652 Joor a May'21, 1940 2,202,772 Durdin May 28g' 1940 2,289,9I3 Jo'or' July 'll, 1942 2,430,592 Wiggins Nov; 111.1947 2,49 7 ,04? Prager et' al Feb. 7, 1950

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