US2404516A - Method of cleaning steam boilers - Google Patents

Description

July 23, 1946. F. w. MILLER 3 5 METHOD OF CLEANING STEAM BOILERS I Original FiledJuly 3, 1941 2 Sheets-Sheet 1 PH rm ron' REF/l. L

INVENTOR.

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July 23, 1946. F. w. MILLER 3 5 15- METQ'IQD OF CLEANING ST EAM BOILERS o gginar Fild July 5, 1941 2 Sheets--Sheet 2 Patented July 23,1946

PATENT OFFICE METHOD OF CLEANING STEAM BOILERS 7 Frank W. Miller, Chicago, Ill., assignor to Franclare Company, Chicago, Ill., a corporation of Illinois Original application July 3, 1941, Serial No.

400,932. Divided and this application February 3, 1943, Serial No. 474,540

This invention relates to the treatment of steam boilers for the purpose of relieving them of the scale and sludge which accumulates therein during their operation.

The method most commonly employed in cleaning boilers is to blow off the steam and water, drain out any remaining water, and then wash the boiler by delivering jets of wash-out water at various angles and at various locations into the boiler, in an endeavor to loosen and knock oil. the accumulated scale and force the sludge and other solid material toward the drain opening through which it is discharged.

The opening up of the boiler to atmosphere after the steam and water have been discharged results in a rapid drying and caking of the objectionable solid matter which it is desirable to remove'from the boiler. This drying and caking is increased by the heat existent in the crown sheet and tubes, with the result that the encrusted solid matter adheres with such. tenaciousness to the boiler surfaces that its removal by the jets of washing water is rendered impossible.

One of the purposes of my present invention is to preclude this drying and caking of the solid matter upon the boiler surfaces and to remove the matter from the surfaces while in a soft and uncaked condition. With this end in view, my invention contemplates the internal washing of the boiler with jets of high pressure water while some water and substantial steam pressure remain in the boiler, so that the atmosphere is excluded from the boiler and all the surfaces remain in a wet condition, which is most conducive to the removal of the sludge and solid matter therefrom.

To facilitate an understanding of my inven- 3 Claims. (01. 122-382) tion, I have illustrated on the accompanying drawings as an exemplification one form of apparatus by which my improved method may be carried out.

Referring to the drawings,

Fig. 1 is a schematic view of an apparatus by which my invention may be practiced;

Fig. 2 is a view showing the arrangement employed at one of the drops;

Fig. 3 is a longitudinal sectional view through the water superheater shown in Fig. 2; and

Fig. 4 is a fragmentary detail of one of the adjustable nozzles.

Referring to the drawings more in detail, reference character 5 indicates generally a locomotive stationed at a pit in a roundhouse between two adjacent drops. The apparatus at each drop in the roundhouse is preferably of the character disclosed in my Patent No. 2,260,857. As shown 2 in Fig. 2, a suitable bracket or other support 6 carries the blow-off line I, the refill water line 8, the live steam line 9 comiected to be supplied with steam from the powerhouse boilers, and,in many instances, a washout water line, which in the present instance is not shown.

For the purpose of superheating the refill Water to be delivered to a boiler being treated, a water superheater or heat booster of the char acter illustrated in Fig. 3 is preferably employed. Such a booster comprises "a cylindrical casing ll provided intermediate its ends with a Venturi tube [2 disposed in alignment with a water dee livery nozzle I3 having a flange l4 clamped to the upper end of the casing H by supportingbolts I5 and IS. The inlet end of the nozzle is connected .by a pipe H with the refill water line 8, and in the pipe ll is interposed a check valve 18 and a shut-off valve l9. The superheater may be mounted at any desirable height above the floor, but when mounted sufficiently high to be out of the way of workmen around the pits, as illustrated in Fig. 2, the valve I9 is equipped with a an operating lever 2| adapted to be operated through the intermediary or pull chains 22 and,23.

A pipe 24 is connected at one end with the casing ll above the Venturi tube l2, so as to communicate with the valve 25su1rounding the nozzle l3 and receives its steam supply from the steam line 9. The pipe 24 is preferably equipped with a shut-off valve 26 and with a regulating valve 21 by which the amount of steam delivered to the superheater may be regulated. This valve also, when located at an inaccessible height, is equipped with operating pull chains 28.

A branch 29 leading from the casing H below the Venturi is connected by a pipe 3| with the blow-ofi line 1, and this pipe is also equipped with a check valve .32 and a shut-off valve 33 adapted to be operated by lever 34 to which are connected operating pull chains 35 and 36 i A flexible conduit in the form of a hose or a pipe 31 provided with flexible joints 38 is equipped at its free end with a coupling wrench 39 by which the conduit may be connected with the blow-off cook or the washout plugs of 'a locomotive boiler.

Referring to the schematic layout of Figure 1, it will be apparent thatthe steam line 9, the blow-off line 1 and the refill line 8 may be connected with the locomotive boiler through the common conduit 31 at will. The various connections are established as desired through manipulation of the valves 33, I3 and 21. From this figur it will be apparent that the blow -ofi li e is adapted to deliver into a steam separator 4| discharged through a pipe line 42 either to a waste conduit or preferably to a storage tank where the water is stored for boiler washout and other useful purposes.

2,404,516 IT Ti 1;:"11'

ously stated, is then further heated by steam from the line I delivered through valve 21 until the temperature of the high pressure water When The sludge accumulated in the.

separator may be discharged to waste at suitable intervals through a discharge pipe 43 controlled by a valve 44.

is circulated to condense the steam. This condensing water is taken from the refill storage tank 4'! and delivered by a pump 48 through the line 49 to the condenser, from which it is returned through the line 5| into the refill storage tank.

Additional water is supplied to the tank as re-' quired through a fresh water supply pipe 52. The details, not shown, of the condensing system may be of the general type disclosed in my prior Patent No. 2,135,407, issued November ,1, 1938. Refill water is delivered to the refill line 8 from the storage tank 4'! by means of a pump 53 in the usual manner. V

In practicing my improved method of treating boilers, the system above described is utilized in the following manner:

IA locomotive to be treated is positioned on a pit between two drops and thelefthand drop, for instance, viewing Fig. l 1 is connected thereto 1 through the conduit 37 which is attached to the blow-off cock of the locomotive. Valves I9 and 2! are closed and valve 33 is opened, thereby per- 1 mitting the boiler contents to be blown off through the blow-off line 1, the steam and water being separated by the separator 4!, the blow-oil" water being thrown away or conserved, as preferred,- 1 and the steam being condensed and stored in the refill storage tank.

The steam from the separator is conducted through a line 45 to a condenser 46, preferably of the open type through which water surfaces.

Instead of blowing off all of the water and steam from the boiler, then opening up the boiler and washing it out as hasheretofore been cus- 'tomary, my invention contemplates interrupting the blowing off operation when about two-thirds ofthe water has been blown off and about 100 pounds steam pressure remains in the boiler.

1 is'made successively to the various washout plugs,

Thisinterruption is effected by closing the valve 1 33. Thereupon'the conduit 37; is connected with the boiler for washing purposes. The connection into steam but is delivered as a solid high pres-' sure jet against various interior surfaces of the boiler so as to remove the sludge, scale and other solid matter which has accumulated on these Since the boiler still contains water and steam and has not been opened to atmosphere as has heretofore been customary, no opportunity has been afforded for the accumulated solid matter to become caked upon the boiler surfaces, consequently, it is in a somewhat soft and non-adherent condition which is conducive to its.

removal from the boiler surfaces. The maintenance of the boiler in hot condition and the delivery of hot washing water also contribute toward the freeing of the solid matter from the boiler surfaces, so that greatly superior results are attained than are possible with the usual practice where the boiler is permitted to cool down and is washed with relatively cool water.

After the washing of the interior of th boiler with high pressure high temperature water has been partially completed, the blowing off operation is again resumed by opening the left-hand valve 33' (viewing Fig. 1) so that the solid matter which has been washed off of the boiler surfaces will be blown out of the boiler along with the blow-off water and deposited in the separator 4 I, from which it may be discharged as previously explained. The washing of the boiler with'hot high pressure Water may be continued during the final blowing oif operation, with the result that when the boiler has been completely emptied it is substantially free from the accumulated solid matter, and, unless repairwork i required, it may be immediately refilled without being opened up to atmosphere'or undul cooled down. Even when washed in'accordance with my method, without being opened. to' atmosphere, the temperature of the boiler is materiallyreduced below the normal working temperature, so that some contraction of the boiler hasv occurred, ,The

' ordinary practice of washing boilers, and, since nozzles disposed inside the boiler and adapted to 1 be turned tovarious positions so as to discharge 2, cleaning jet of waterzin various directions with- 1 in the boiler. is indicated by reference character 53 in Fig. 4.

A typical nozzle for this purpose This nozzle is rotatably 'mountedln the plug 5 4 and connected by a swiveljoint 55-wi'th the conduit 31. Rotation of the nozzle to vary the direction, of discharge therefromis effected by When the connection at 150 to 200 pounds'pressure, which is materially perature approaching200", and, as has been previthe boiler has remained under steam pressure during, practically the entire washing operation, such contraction as does occur is uniform and does not impose injurious strains and stresses upon thevarious boiler parts. It believed that procedure. in accordance with my methodwill be understood from the force going, and that the advantages resulting ;from the practice of this method will be appreciated, all without further description. Variations in the method hereinabove described as illustrativea-nd wide modification in the apparatus employedjin practicing the method may obviouslybe resorted to Within the scope of the invention as :defined'in the following claims. t This application is a division of my co-pending application Serial No, 400,932,.filed July 3, ,;1941 and which 7 has matured into 'Patent Number 2,318,247, May 4, 1943; r r Iclaim; v 1. The method of cleaning boilerswhich consists in partially blowing down a boiler leaving therein about OHS-thlldiOfltS :normal liquidco ltents under a substantial steam pressure, loosening and removing accumulated solid matter from the boiler without permitting contact of the atmosphere therewith by delivering into said boiler against the accumulated matter water at a pressure above and at a temperatur below the pressure and temperature of the boiler, and blowing ofi the thus loosened solid matter together with the Water remaining in the boiler.

2. The method of cleanin steam boilers while under steam pressure which consists in partially blowing off the steam and water in the boiler until approximately one-third of thevnormal amount of liquid remains therein under substantial steam pressure, delivering into said boiler against the solid matter to be removed therefrom a jet of water under pressure greaterthan the existent boiler pressure and at a. temperature only slightly below the temperature existent in the boiler, and thereafter blowing off the remaining water together with the solid matter loosened by the ac-

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