US2283451A - Method of reconditioning boilers - Google Patents

Description

May 19, 1942. F. W. MILLER METHOD oF REcoNDITIoNING BQILERs 2 sheets-sheet 1` Filed oct. 2 0, 1959 IVENTOR.

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METHOD OF'RECONDITIONING BOILERS- Filed 001;. 20, 1959` i QQ n @j E@ j Patente-cl May 19, 1942 s'rres y T eric METHOD OF RECONDITIONING BOILERS Frank W. Miller, Chicago, Ill., assigner to Fran- .clare Company, Chicago, Ill., a Ycorporation of Iliinois 4 Claims.

This invention relates to the reconditioning of Ythe fluid contents of steam boilers generally, the

method of this application being advantageous in the reconditioning of various types of steam boilers and particularly locomotive boilers. This application is a continuation in part of my pending application Serial No. 166,509, led September 30, 1937.

The complete blowing down, washing out, and refilling of a steam boiler is not only an expensive operation in and of itself, but the cooling o with consequent contraction of the boiler, including the tubes and the crown sheets and the reheating with the consequent expension thereof impose stresses and strains upon the boiler parts which reduce the longevity and the serviceability of any boiler whether stationary or portable. To obviate the necessity of frequent complete blowdowns lwith their attendant expense, loss of service time while being blown down, washed out and refilled and the resultant detrimental effects of contraction and expansion upon the boiler itself, I have devised a method by which a boiler may be reconditioned while under steam pressure so that it is quickly available for use again and during the reconditioning does not become cooled off.

My novel method while applicable to any steam boiler is particularly valuable in connection with the servicing of locomotives where it :3. is highly desirable for purposes of economy thatv such that a locomotive boiler prior to my invention was required to be completely blown down and washed out once in every ten days, such boilers may, when reconditioned in accordance with my method, be maintained in service without complete blowing down and washing out for a period of from four to six weeks.

For the purpose of kfacilitating an understanding of the principles of my invention, I have illustrated on the accompanying drawings a preferred embodiment thereof, although it should be understood that the invention is capable of embodiment in apparatus both for locomotive and stationary boilers in structural assemblies differing substantially from the present illustrative disclosure. Referring to these drawings,

Fig. l is a diagrammatic view of a system embodying the principles of my invention;

Fig. 2 is afragmentary elevation partially in section of'one of the servicing units which is located adjacent a round house stall; and

Fig'. 3 is a vertical sectional view through the heat booster shown in Fig. 2.

Referring now to the drawings and particularly to Fig. 1, a pair of locomotives designated by reference characters 5 land 6 are positioned with reference to the service equipment as they would be in the round house, it being understood Y be later described, with the Vmain drops 8 of each servicing unit in a manner to be later described, and the drops 8 are adapted to be connected through exible connections 9 either in the form Y of exible conduits or pipes and flexible joints II, as shown in Fig. 2 with the boiler of a locomotive 6 by means of a suitable wrench I0.

When the valves are suitably set, as will be laterk explained, the blow-off products from the boiler consisting of steam and water are blown off through the drops` I into the blow-off main I2 by which they are delivered into the separator I3. In the separator, which is preferably of the centrifugal type, the water is separated from the steam and is conducted to the washout tank I4. From the washout tank, the water may be delivered by the pump I5 into the washout main I6 from which it may be delivered through the washoutdropsl to the boiler to be washed out, the drops Il being customarily equipped with a hose or other flexible conduit for delivering the water into the boiler.

The steam rising from the separator i3 is conducted through pipe I8 to acondenser I9 where.

it is condensed by water delivered through the pipe 2l by the circulating pump Z2 which withdraws this water through the pipe 23 from the p rell tank 24'and returns the water with the Vcondensedl steam from the condenser back to the reiill tank vthrough pipe 25. The water level in the rell tank is maintained by the vadmission of cold water from the pipe 2G controlled by the y float valve 2l.

Water for boiler reiilling purposes is withdrawn i the temperature of the returning water is raised by the admission of live steam through the pipe 32, the delivery of this steam being controlled by thermostatic valve 33 in operative communication with the return line 29 so that this valve is opened and closed in accordance with the variations in temperature of the returning water. 'Ihe operation of pump 21 which receives its steam supply through the pipe 34 is controlled by a pressure governor 35 so that a substantial pressure of preferably 120 to 150 pounds more or less, but in any event greater than the pressure in the boiler being treated, is maintained in the re-lll line. A live steam pipe 36 is connected to receive its steam supply from a round house boiler r other source extraneous to the locomotives, and this pipe is provided with a pressure regulator 31 adapted to maintain the steam pressure in the steam line 38 substantially below the water pressure in the refill main 28 and preferably Vat about 110 pounds. In other words, for reasons which will be explained, the pressure in the steam line 38 is maintained substantially below the water pressure in the rell line 2B.

Referring now to Fig. 2 wherein the washout, blow-olf, rell, and live steam lines shown in section are supported upon a suitable bracket 39 at an elevation well above the locomotives in the round house, it Will be observed that each of these lines is connected with the main drop 8 of the service unit in a manner which Will now be explained. The refill line 28 is connected through a riser 4I, preferably of inverted U shape with the upper end 42 of a nozzle 43 projecting into the upper end of casing 44 of the heat booster and secured to the casing by bolts 45 which also serve as a hanger for the booster. One leg of the riser is equipped with a check valve 45 adapted to prevent reverse flow into the refill line and with a shut-off valve 41 provided with an operating lever 4S which may be actuated from the oor through the medium of drop chains 49 and 5l equipped with hand grips 52 and 53 respectively. n

The booster casing 44 is of elongated cylindrical shape provided with an internal shoulder 54 upon which a anged Venturi tube 55 is seated in alignment with and slightly spaced from the end of the nozzle 43, the bore of which, as will be apparent from Fig. 3, is tapered.

The live steam line 38 is connected with the interior of the casing 44 in proximity to the nozzle 43 and ahead of the venturi 55, through a pipe 56 which is equipped with a hand shutoff valve 51 operable from the oor through chains 56 and with an adjustable regulating valve 59, which may be manually set to deliver at any predetermined'rate of flow.

The casing 44 is also provided with a lateral branch 6I which is connected through a pipe 62 to the blow-olf line I2, this pipe being provided with a check valve 63 to prevent reverse flow from blow-olf line I2 tc the booster kand with a shut-oil valve 64 provided with an operating lever 65 which may be actuated from the oor through the chains 66 and 61 equipped respectively with the hand grips 68 and 69.

In carrying out my improved method, the following procedure is adopted.

Valves 41 and 51 are closed, valve 64 is opened, and the conduit 9 is connected with the boiler 6 to be conditioned. A portion of the contaminated water in the boiler is blown-off through the blow-off line l2 and accumulated in the washout tank I4 in the usual manner. In instances where the saving of the blow-off water is of no consequence, such water may be blown directly into a pit or sump from which it may drain to the sewer.

The blowing olf of the water is continued under the steam pressure of the boiler until a desired portion, usually several hundred gallons determinable from the gage glass, has been discharged, whereupon valve 64 is closed and valves 41 and 51 are open. Refill water delivered by high pressure pump 21' at a pressure substantially in excess of the steam pressure remaining in the boiler is now delivered from the refill line through the nozzle 43, the venturi 55, the drop 8, and the conduit 9 into the boiler to replace that which has been blown o. This refill water delivered under pressure is preferably at a temperature in the neighborhood of 200 F. when it reaches the booster 44. Simultaneously, steam at a lower pressure than the water and usually under a pressure of approximately pounds is delivered from the steam main 38 through pipe 56 into the booster casing 44 around the nozzle 43 and ahead of the venturi 55. As the water under higher pressure than the steam is discharged by the nozzle through the venturi its velocity is increased and its static pressure is decreased at the throat of the venturi so that the steam surrounding the nozzle is drawn into the water in large quantities, thereby raising the temperature of the water from around 200 to 240 or more. The water, therefore, when delivered into the boiler is considerably above steaming temperature and is delivered in a superheated condition under a pressure greater than the boiler pressure, with the result that not only is the water level in the boiler raised, b ut the steam pressure therein is substantially main` tained or in some instances even increased.

The delivery to the boiler of this superheated,

high pressure Water is continued until the origi- Ywater is repeated until the condition of the water in the boiler resulting from successive replacements of contaminated water with fresh water has'produced a condition in the boiler satisfactory for further continued operation of the' boiler. When this condition has been reached, the boiler is still under steam pressure, and upon renewal of the re is very quickly restored to a condition suitable for service.

It will thus be seen that in accordance with my method, the boiler is reconditioned while still maintained under steam pressure, preferably withv the fires banked, so that when a suitable condition of the boiler water has been attained by repeated partial blowing olf of contaminated water and replacement thereof by fresh water, the boiler is still under at least suflicient steam pressure to enable the locomotive to move under its own power, and upon reinvigorating the fires, the steam pressure can be very quickly restored to service pressure.

Should in any instance as the result of a low initial pressure in the boiler or for other reasons,

boiler so as to raise the boiler pressure to the l requisite point.

It is believed that my invention and many of its attendant advantages will be understood and appreciated from the foregoing, and it should be manifest that the structural details shown and described for illustrative purposes may be varied within wide limits within the scope of my invention as defined in the following claims.

I claim:

l. The method of reconditioning a locomotive boiler by reduction of concentrates accumulated therein while maintaining said boiler under substantially operative steam pressure and while the boiler fire is substantially inactive, which comprises blowing off from below the boiler water level by means of said steam pressure a substantial portion of the contaminated boiler water while leaving suflicient water in said boiler to maintain said steam pressure, delivering into the boiler a quantity of superheated refill water under a pressure greater than the boiler pressure and at a temperature higher than the steam flash temperature of the boiler Water under the existing boiler pressure and repeating said blowoff and water replacement operations in alternation until the desired concentrate reduction has been attained.

2. The method of reconditioning a steam boiler by removal of concentrates accumulated therein while said boiler is under substantially operative steam pressure and While the boiler re is substantially inactive, which comprises, blowing off below the water level a substantial portion of the contaminated boiler water while leaving sufficient water in said boiler to maintain said steam pressure, terminating such blow-o, connecting the boiler with a rell water supply under a pressure greater than the boiler preshigher than the temperature of the remaining boiler water, introducing such high pressure high temperature refill water into the boiler to replace the contaminated blown off water, terminating such delivery of refill water to the boiler, and thereafter repeating said blow-01T and refill operations in alternationuntil satisfactory boiler water conditions have been attained.

3. The method of reconditioning a steam boiler by removal of concentrates accumulated therein while said boiler is under substantially operative steam pressure and while the boiler fire is substantially inactive, which comprises blowing off a substantial portion of the contaminated boiler water while leaving sufficient water in said boiler to maintain said steam pressure, and replacing said blown off water subsequently to the blowing off operation by delivering into the boiler fresh refill water at a higher temperature than the temperature of the boiler water and under a greater pressure than the boiler pressure to Y thereby raise both the water level and the steam pressure in the boiler.

4. The method of reconditioning a locomotive boiler by removal of accumulated concentrates while said boiler is under substantially operative steam pressure and while the boiler re is substantially inactive, which comprises blowing off a substantial portion of the contaminated boiler water while leaving sufficient water in said boiler to maintain said steam pressure, discontinuing the blow-olf operation, restoring the water level and steam pressure in the boiler by introducing fresh refill water under a pressure greater than the boiler pressure and at a temperature higher than the temperature of the boiler Water, discontinuing the refill operation and repeating in alternation the blowing off and refilling operations until satisfactory boiler water conditions have been attained.

FRANK W. MILLER.

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