US2298154A - Surface condenser - Google Patents

Description

Patented Oct. 6, 1,942

UNITED STATES I PATENT 'OFFICE sURFAcE coNDENsEIt Samuel Pennella, East Orange, N. J. Application' December 31, 1941, serial No. 425,013

v (ol. 257-236)A 3 Claims.

This invention relates to surface condensers and more particularly to a means of. mounting the tubes in the tube sheets or tube heads of a condenser.

It is a well established fact that in surface condensers utilizing water as a medium for condensing steam that. the tubes of the condenser through which the cooling water circulates corrode and erode under the action of the water to become so eaten away as to cause leakage is to remove the tubes and retube the condenser. In surface steam condensers employed in power plants, the tubes are generally of brass or a copper alloy and range in length from sixteen to thirty feet, depending upon the capacity of the condenser, while in marine condensers they are from twelve feet upwards in length. Such tubes are expensive and the present practice of re moving the' tubes and scrapping them when only a small portion of their length is unfit f or service is a costly, extravagant and wasteful one. Not only is it costly from a labor and `materia1 stand- Apoint tc retube a condenser, but such work necessitates taking the condenser out of service for a comparatively long time with the resultant loss of productive work of the entire power plant unit in which the condenser is installed.

An object of the present inventionvis to provide a construction whereby the unt ends of the tubes may be removed without removing the tubes from the'condenser, thus permitting continued use of the unaffected portions of the tubes and very materially increasing the ,length of their period of service, and further permitting the'condenser to be again made tight and in good operating condition withoutthe expense of `new tubes, of labor involved in retubing, and without requiring the shutting down of the power unit in which the condenser is employed except for only a fraction of the time as. would be re- 4quired for retubing.

A further object of the inventionv is to provide a construction for holding the tubes in position and in duid-tight connection with the tube sheets which, while holding the Atubes eagainst slippage under operatingconditions of the contudinally threugh the tube sheets for cutting off the unfit ends, without disrupting thepacked, fluid-tight connection and 4without requiring 'repacking of the tubes.

With th'ese and other objects in view, as lmay appear from the accompanying specification, the invention consists of variousl features of construction and combination of parts, which will be first described in connection with the accompanying drawing, showing a surface condenser of the preferred form embodying the invention, and the features forming the invention will be specically pointed out in the claims. A

In the drawing:

Figure 1 is a longitudinal section through a surface condenser embodying the present invention.

Figure 2 is a fragmentary view illustrating a corroded, eroded tube in its original position.

Figure 3 is a view similar to Figure 2, showing the tube driven longitudinally through the' tube.

' the inlet end of the condenser and by a second denser, will permit the tube to be driven 'longi- 55 Figure 4 is a view similar to Figures 2 and 3,

showing the tube after the faulty end has been cut o. y

Referring more particularly to the drawing, l

indicates a surface condenser of any approved l type having an inlet water box 2 and 'an outlet water box 3, and having a plurality of water circulating tubes 4 extending through the condenser from the inlet water box 2 tdthe outlet water box 3. f i

The tubes are supported by a tube sheet 5 at tube sheet 6 at the` outlet end.

' It is the usual practice in the building of surface condensers to have both the inletand outlet ends of the tubes flush with 4the outer faces of the two tube sheets or tube heads, land thus, when the inlet ends ofthe tubes becomel corroded or eroded, causing leakage of the circulatingwater into the condenser space, it is necessary `to remove the entire ltube and substitute ai new.'tube therefor. absorbing and not only involves the cost o f an entirely new tube and its replacementv in the, condenser, but requires also the shutting down of the condenser for a protracted period of time for the replacement operation.

`The present invention comprehends a structure whereby leakage of the tubes maybe corrected This is costly and time without requiring retubing of the condenser. It is well known and an established fact that the corrosion of condenser tubes occurs at and a short vdistance inwardly from their inlet ends, this part of -the tubes becoming eaten away whilertheremaining portion of the tubes is in good condition and still serviceable. Therefore, in the carrying out of the present invention, the

-tubes 4 are longer than the space between the two outer surfaces of the tube sheets 5 and 6 and when initially installed have their inlet ends.

ferrules I0 threaded - intothe tube sheets 5 and 6. Thispacking 9 is shown in the drawing as being rings of fibrous material which will swell when wetted so as to provide a fluid-tight joint between the tubes li and the tube sheets 5 and 8. The tubes 4 are ofunform external diameter throughout the entire length and while the packing vstructure 9 grips the tubes in the tube sheets with sufiicient tightness and firmness to hold the tubes against movement relative to the tube sheets under ordinary operating conditions of the condenser, these joints are such that the tubes maybe driven longitudinally through the packings and through the support plates'by the application of impact blows against the projecting ends 8 of the tubes so as to drive the corroded and eroded ends (indicated at I2) outwardly beyond the outer surface of the inlet tube sheet 5, where they may be cut ofi without disrupting the fluid tight connections between the tubes and the tube sheets. This operation permits the condenser to be repaired and the leakyportions of the tubes to be removed, without requiring the retubing of the condenser and permitting the continued use of the uincorroded, uneroded portions of the tubes, very greatly increasing the period of active usefulness of the tubes. It also permits the repair of the condenser in a much shorter time than is required for retubing.

Y While the drawing shows fiber packing rings' 9, it is to be understood that any suitable pack' ing may be employed 'which will provide the fluid-tight connection between the tubes and tube sheets and hold the tubes against move:

ment relative to the tube sheets under normal conditions, but which will permit the tubes to be driven therethrough without disruption of the joints, without departing from thespirit of the on the inlet end than on the outlet end of the tubes, -thereby permitting the tubes to slide slightly in the packing of the outlet end of the condenser under expansion and contraction of the condenser due to heat variances during its operation.

It will be understood that the invention is not to be limited to the specific construction or arrangement of parts shown, but that they may be widely modified within the invention defined by the claims.

What is claimed is:

1. In a surface condenser, tube sheets, water circulating tubes carried by and extending from one tube sheet to the -other and projecting beyond the tube sheet at the outlet ends of the to be driven longitudinally through the tubey sheets to allow the inlet ends of the tubes to be cut off without disrupting the connection between the tubes'and the tube sheets.

2. In a surface condenser, tube sheets, water circulating tubes carried by and extendingA from one tube sheet to the other and projecting beyond the tube sheet at'the outlet ends of the tubes only and having their inlet ends flush with the outer surface of the adjacent tube sheet, said tubes being of uniform external diameter throughout their entire length, and packing carried by said tube sheets and about said tubes and forming fluid-tight joints between the tubes and tube sheets which under normal conditions restrains the tubes at the inlet' end against movement relative to their tube sheet but is adapted under impact to allow the tubes to be driven 4longitudinally through the tube sheets without disrupting the fluid tight joints.

3. In a surface condenser, tube sheets, water circulating tubes carried by and extending from one tube sheet to the other'and projecting beyond thetube sheetat the outlet ends of the tubes only and having their inlet ends ilush with the outer surface of the adjacent tube sheet, said tubes being of uniform external diameter `throughout their entire length, and fibrous packing rings carried by the tube sheets and engaging about the tubes, said packing rings adapted'to swell upon being wetted to form duid-tight joints between the tubes and the tube sheets of such nature as to restrain the tubes against movement relative to the tube'sneets at the inlet end under normal operating conditions of the condenser but to permit the tubes under impact to be driven longitudinally through the tube sheets without disrupting the fluid-tight joints.

l SAMUEL PENNELLA.

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