US1654261A - Deaebatob - Google Patents

Description

Dec. 27, 1927. 1,654,261

R. c. JONES DEAERATOR Filed Nov. 19. 1926 INVENTOR:

fgusse C. James;

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Hi5 ATT RNEYS.

Patented Dec. 27, 1927.

UNITED STATES PATENT OFFICE.

RUSSELL C. JONES, OF BRONXVILLE, NEXV YORK, ASSIGNOR TO THE GRISCOM-RUSSELL COMPANY, OF NEW YORK, N. Y.,

A CORPORATION OF DELAWARE.

DEAERA'IOR.

Application filed November 19, 1926.

The present invention relates to deaerating apparatus for steam generating systems and has to do with the furnishing of sub stantially gaslree water to the boilers.

lVater as supplied to a steam generating plant usually contains relatively large quantities of gases in solution. These various gases, notably oxygen, which are dissolved in the feed water are liberated in the boilers and other parts of the apparatus under the conditions to which the water is subjected and react on the metal of the various apparatus with the result that pitting and corroding occur. It is therefore common practice to subject the boiler feed water to a degassing treatment before the water is admitted to the boilers in order that the injurious gases may be removed from solution and expelled from the system.

Various types of apparatus for deaeratmg boiler feed water have been proposed. For instance, it has been proposed to deaerate the water in an apparatus consisting of two chambers through which the water passes in series relation. The first of these chambers is a heating chamber and in this chamber the water is heated to a temperature approaching its boiling point under the pressure conditions maintained in that chamber. The heated water from this chamber is then admitted to the second chamber where ebul lition occurs either as the result of additional heating steam admitted to the second chamber or as the result of reduced pressure in the second chamber in which latter case ebullition occurs by reason of the contained heat ot' the liquid. It has also been proposed to deaerate water by dripping it upon a heated surface in which case the liquid is usually sprayed upon a bundle of heating tubes so that the liquid runs over the tube surfaces in the form of a thin lilm and is heated by reason of its contact with the tubes. Deaeration is satisfactorily accomplished if the liquid to be deaerated is heated to its boiling point corresponding to the pressure under which it is maintained and is then allowed to remain subjected to these conditions for a sullicient length of time to permit all of the contained gases to remove themselves from the liquid.

In copending application Serial No. 600,178, filed November 10, 1922, in the Serial No. 149,328.

name of Joseph Price and assigned to the present assignee, there is disclosed a donoratmg apparatus which consists of a containing shell in the bottom of which is maintained a principal body oi the liquid under treatment. The water to be deaeraled is admitted at-the top of the chamber and "falls over a series o'l bullies until it eventually reaches the principal liquid body in the lower part of the apparatus. Heating steam is preferably admitted by means of a perforated pipe submerged in the liquid body so that the bubbling of the steam through the liquid will effect an agitation and will thus assist; in bringing the solution to equilibrium and consequently in effecting complete removal of dissolved gases. The present invention is in a sense a development and improven'ient on the apparatus disclosed in this copending application.

In the present apparatus, the liquid is admitted at the upper portion of the unit and falls downwardly through the apparatus over a series of ballles which thoroughly agitate it and distribute it as a rain of falling drops and the liquid eventually accumulates in a principal body of liquid in the lower part of the apparatus. Steam is allowed to expand through this rain, and would serve, according to the commonly accepted idea, to sutliciently deaerate the incoming liquid. However, since this is not actually the case, the present invention contemplates also providing a heating unit consisting of a plurality of heat transferring tubes submerged in the principal liquid body and heating steam is passed through these tubes at a relatively high 'elocity. This heating element. causes ebullition ot the liquid body and thus makes for thorough scrubbing or removal of gases from the I The accompanying drawings illustrate a preferred embodiment of the invention. in these drawings,

Figure '1 is a sectional view of the apparatus of the present invention;

Figure Zis a modification of the apparatus shown in Figure 1; and

Figure 3 is a still further modification oil the apparatus shown in Figure 1..

Referring now to the drawings more in detail by numeral, 1 indicates the containing shell or housing of the deaerator in the lower portion of which a principal body of liquid Q-according to the in'iproved purpose of the invention is normally maintained. The incoming water enters at the top of the apparatus through the line 8, and a valve 5 in this line operated through alinliage 7 by means of a float 6 regulates itor inaii'itaining a substanti ally constant liquid level in the up paratus. The incoming liquid passes, which in the subsistentapparatus is the only part ot the i'eed water receiving treatment, down the length of the apparatus over a series of battles 9. Alternate bullies as shown are provided with central openings and alternate battles are provided with annular passages at their outer edges so that the steam and gases rising through the apparatus assume a tortuous path as indicated. generally by the arrows and are thus brmight into repeated and intimate contact with the liquid spray descending through the apparatus. The uncondei'isablegases are drawn out oi the apparatus through the vent or discharge line 11. lVithdrawal of these gases is pret- "erably effected by means of a steam ejector 12 connected to the line 11 as shown. De-aerated water may be conducted oil through the line 13 provided near the bottom ot the shell 1.

According to the present invention in order to preclude any possibility of there being any gases left in the teed water, there is subu'ierged in the principal body of liquid in the lower pOltlOI]. ot the apparatus a haul: of heating tubes 14. These tubes preferably extend between rigidly spaced headers 15 as shown and may be slightly bowed so that by subjection to a'material change in temperature, the tubes will lien and will thus loosen and crack oil deposits of scale which correspondingly high efficiency of heat transfer.

The steam passing the heat transferring tubes le uncondensed enters line 17, from whence it is passed into the interior of the deaerating chamber through the medium of the orifice plate 18. The size of the orifice in the plate 18 so chosen as to maintain a slight pressure dii'l'erence between the steam within the tubes i l and that within the dcacrator shell 1. This pressure differential may be from, say, one tolive pounds per square inch. In this fashion a slight temperature dilli'eif'ence is nmintained between the steam within the heating tubes 1.4. and the water in the shell which dilii'erencc is suliicient to insure cbullition ot the liquid body in. the shell with the re ult that cll'cctivc scrubbing or mechanical removal of liberated air from the water in the bottom oil? the shell is accomplished. The steam cntering the deaerating chamber through the orilice plate 18 comes inuncdiately into diect contact with the incoming water flowing down over the battle plates 9.

The present invention also contemplates causing the steam passing through the submerged heating element M uncondensed, to flow into a perforated pipe 26, also located beneath. the liquid level in the deaerating chamber, and connected to the discl'large header by a byiiass 529, and coi'itrollcd by a valve 30 A'brai'ich line 27 taps into the bypassQS), as shown in Figure 1., and leads into the dcaerating chamber above the liquid level therein, so that all, or any predetermined part, of the steam passing the heating elenient l-l uncondensed, may be conducted directly into the deaerating chamber above theliquid level.

Ordinarily, all. of the steam is passed through the tubes 14. and then into the dcaerating chamber through the orifice plate 18 GXCGPtlDg, of course, that portion of the steam which is condensed and is withdrawn through the trap 16. Under ct. "ain (JllClHl'I- stances it may, however, be desirable to admit a certain amount 0t steam directly to the deacrating chamber without first caus log it to traverse the heating tubes ll. l ith this situation the valve .30 in steam line .19 is opened to a certain extent and a desired an'iount ot steam admitted directly into the deaeratii chamber, while at the same time a desired portion oi the steam pas. is down through the line 21 and enters the submerged heating element .lel utter which. the uncondensed ')ortion ot the steam finds its way through line 17 and. orifice plate 18 into the deaerating chan'iber 1. The valve 20 is a pressure reducing valve designed to maintain in the deaerating cham her a pressure corresponding to that to which the orilice plate 18 is intended to regulate. The pressure in the deaerator should. be slightly below that in the heating tubes l l for the purpose o1. insuring the tempera Ill] iLlU

ture differential desirable in maintaining a continuous and satisfactory ebullition of the liquid body 2.

In Figure 3 there is illustrated an automatic valve 523 for maintaininga substantially constantpressure and temperature differential between the submerged heating element and the deaerating chamber. The 'alve here shown is a diaphragm valve having lines 2% and 25 comnmnicati'ng respectively with the pressure in the deaerating chamber and the pressure in the submerged heating element so that the valve will regulate for constant pressure differential with the result that a substantially constant tem perature differential will also be maintained.

For the purpose of affording an ellieientheat transfer a high velocity of steam within the heating tubes 14 is desirable. This effect may be enhanced if desired by the provision of a multi-pass heating unit of the type shown in Figure 3. In this figure a two-pass unit is shown, and the steam is caused to travel the length of the unit two times at relatively high velocity before it is passed along to the line 17 and orifice plate 18. In this figure. the heating element is built within the d-eaerating chamber and is provided with stay rods 22 for the purpose of rigidly spacing the tube sheets so that llexure ot' the tubes to produce a scale cracking action can be obtained. It is to be understood that this internal type of heating element construetion may be employed either with a single pass or a multi-pass unit.

The present invention is eminently advantageous in certain instances where it is desired to secure a particularly effective agitation of the body of liquid in this dcaerator. The passing of the additional amount of steam into the liquid body through the perforated pipe 26 produces an unusual and uneXpect-edly great amount of additional agi tation of the liquid, with a resultant increased efficiency of scrubbing and deaerating.

The present application is in part a divisional application of the eopending application of R. C. Jones, filed September 2, 1925, Ser. No. 54,583.

I claim:

1. Deaera-ting apparatus comprising a contaming shell, means for normally maintaining a body of liquid in the lower portion of the shell, means for admitting liquid to be treated above the liquid body in said shell, a heating element submerged in the liquid within said shell, means for supplying heating steam to said element, a perforated pipe submerged in the said body of liquid and means for passing steam issuing from said submerged heating element uncondensed into said perforated pipe.

2. Deaerating apparatus comprising a containing shell, means for normally maintaining a. body of liquid in the lower portion of the shell, means for admitting liquid to'be treated above the liquid body in said shell, a heating element submerged in the liquid within said shell, means for supplying heat ing steam to said element, a perforated pipe submerged in the said body of liquid, means for passing steam issuing from said submerged heating element uncondensed into said perforated pipe, and means for passing a portion of the steam issuing from said submerged heating element into the deaerating chamber above the liquid level therein. i

3. Deaerating apparatus comprising a containing shell, means for normally mainlaining a body of liquid in the lower portion of the shell, means for admitting liquid to be treated above the liquid body in said shell, a heating element submerged in the liquid within said shell, means for supplying heating steam to said element, a perforated pipe submerged in the said body of liquid. means for passing steam issuing from said submerged heating element uncondensed into said perforated pipe, and means for passing a portion of the steam issuing from said submerged heating element into the deaerating chamber above the liquid level therein, comprising a valve interposed between the discharge end of said submerged heating element and the interior of said containing shell, said valve being actuated according to the pressure differential between said heating element and said shell.

In testimony whereof I atlix my signature.

RUSSELL o. JONES.

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