US1965595A - Process and apparatus for cleaning steam from a steam boiler - Google Patents

Description

July 1o, 1934. A D. s JACOBUS 1,965,595

PROCESS AND APPARATUS FOR CLEANING STEAM FROM A STEAM BOILER Original Filed Jan. 19, 1928 2 sheets-sheet 1 July 1o, 1934. D. SQACOBUS 1,965,595

PROCESS AND APPARATUS FOR CLEANING. STEAM FROM A STEAM BOILER Original Filed Jan. 19. 1928 2 Sheets-Sheet 2 Patented July 1'0, 1934 PATENT `OFFICE PROCESS AND APPARATUS FOR CLEANING STEAM FROM A STEAM BOILEB David S. Jacobus, Montclair, N. J., assignor to The Babcock & Wilcox Company, Bayonne, N. J., a corporation of New Jersey Application January 19, 1928, Serial No. 247,765 Renewed November 11, 1932 1 0 claims.

'I'his invention relates to a process and apparatus for removing impurities from steam by Washing the steam with water and then separating the Wash water a'nd impurities from the steam. The invention is especially luseful for removing moisture and solid impurities from steam after it leaves the steam space -of the boiler and before it reaches the superheater that may be provided for superheating the'steam.

The invention will be understood from the description in connection with the. accompanying drawings in which Fig. 1 is a side view partly in section showing an illustrative embodiment of the apparatus for practicing the invention; Fig. 2 is a vertical section on an4 enlarged scale, through the valve controlling device; Fig. 3 is a view similar to Fig. 1 showing a modification; and Fig. 4 is a vertical section through a modiflcation of one of the parts.

In the drawings, reference character 1 indi' cates a water tube boiler that is provided with a superheater 2 and a steam and water drum 3. A pipe 4 leads from the steam space of the steam and water drum-'3 to a larger pipe 5 that is preferably vertical, in which a twisted metal band 6 may be located, similar to the one shown in Fig. 15 of U. S. Patent #1,149,265. The lower end of the pipe 5 is connected to a steam and water separator 8 that may 'be of one of the well known types. Al steam pipe 9 leads from the steam and water separator 8 to the superheater 2, and an outlet pipe 10 lfor the water leads from the lower end of the steam and water separator 8 to a heat interchanger 11.

An outlet pipe 12 is providednear the lower portion of the heat interchanger 11 and is controlled by the valve 13 which is in turn controlled by the float 14 in the heat interchanger 11. A hand controlled blowofl. valve 15 is provided at the bottom of the heat interchanger 1 1. An inlet 16 for clear distilled water leads to the coil 17 inside the heat ,interchangen and an outlet pipe 18 leads from this coil to the pipe 5 above the upper end of the ribbon 6, a valve 19 being provided in the pipe 18.

A valve 25 that is automatically controlled by the rate of flow of steam from the boiler is also located in the pipe 18.

, `The extent of opening of the valve 25 is made .to dependupon the rate of ow of steam from the boilerl so that the amount of wash water for the steam will be. proportional to the amount of the steam generated. This control can be eifected by connections to different portions of the system through which the steam ows, and between there will be a material fall of pressure on in- ,65

creasing the rate of flow of steam from the boiler and no orifice employed', such as the one shown at 26. A number of metal diaphragms 30 connected to form a bellows, is located inside the casing 29 and is made to contract and expand in accordance with the differential of pressure in the pipes 27 and 28. The pipe 27 leads steam into the casing '29 on the outside of the bellws and the pipe 28 leads steam into the inside of the bellows. The bellows is connected by the link 32 to a lever 33 that is attached to the shaft 34 which extends through a stuiiing box to the' outside of the casing. One end of the lever 35 is attached to the outwardly extending part of the shaft 34 and the'other end of this lever is connected by means of a link 36, to a lever 37 that is attached to the shaft 38. A lever 39 carrying a slidable or adjustable weight `40 is also connected'to theshaft 38 and the shaft 38 extends into a housing 41. Oneend of the lever 42 inside the housing 41 is attached to the shaft 38 and the other end of this lever is connected to the stem 43 of the valve 25.

The operation isr as follows: Steam vpasses through the pipe 4 into the vertical pipe 5 where clean distilled water, which is of greater purity than that contained in the boiler; is mixed with the steam and washes out the moisture and other impurities, the washing of the steam being facilitated by the twisted strip 6. The mixture of steam and water is separated in the separator 8, the steam going through a pipe 9 to the superheater, and the water and impurities passingginto the heat interchanger 11. The float 14 controlsthe valve 13 so that the water escapes from the.

provided it does not contain too great a proportion ,of solids, depending upon the degreeof purity desired in the steam and the effectiveness with which the steam is freed from the wash water.

I heated, thereby saving heat that would otherwise be wasted. The water passes through the pipe 18 -into the Yvertical pipe 5 at a rate proportional to the amount of steam leaving the boiler and controlled by the rate of steam flow.

`An increase in the rate of wash water for the steam is caused to take place by an increase in the rate of steam flow, because an increased differential in pressure between the steam in the pipes 27 and 28 takes' place when the rate of steam passing through the orifice increases, so that the bellows 30 is collapsed, and by means of the lever mechanism and shafts, the valve 25 is opened more. By Aadjusting the levers 39 and 42 on the shaft 38 and also adjusting the weight 40 on the lever 39, the proportions of wash water to the steam can be varied. In accomplishing this adjustment the lever 39 may be turned to any required angle on the shaft 38, for example, it might be placed in the dotted line position shown in Fig. 2. A l if l 4 l In the modication shown in Fig. 3, the pipe 4 from the steam space of the steam d water drum 3 divides into two valved branches 50 that lead to vertical chambers 51 and 52. The chambers 51 and 52 are provivded with metallic grids through which and over which steam passes with water that is sprayed into the same for washing the steam. Outlet pipes 54 and 55 from the lower water separators 56 and 57, respectively. The

hand valve control blowoff pipes 58 and 59 lead from the lower ends of the separators 56 and 57, and pipes 62 controlled by valves 63 and 64 lead from the steamspaces of the separators 56 and 57 to a' pipe 65 that leads to a steam and water separator 66. A blowoiI pipe 67 is connected to the lower end of the separator 66 and a steam trap 68 islocated in this blowoi. A steam pipe 69 leads from the steam space of the separator 66 to the superheater 2. Valved pipes 7D and 71 lead from the normal water level in the separators 56 and 57 to the heat exchanger 72 that is provided with a float 73 to control the valve 74 in the discharge pipe near the lower end of the heat exchanger 72. A blowoif pipe 75 with a hand controlled valve is providedat the bottom of the exchanger 72.

'I'he control mechanism- 29 like the one already described in connection with Fig. 1, controls the valve 76 in the water inlet pipe 77 in Aaccordance with the rate of steam passing through vpipe 4.` VThepipe 77 T'leads to coil 78 in 4heat exchanger 72, from which coil a pipe 79 with valved branchesleads to sprayers 80 and 81 in chambers 5l and 52.- Valved pipe connections 82 and 83 are provided for supplying a large ow oi' water for washing the grids should they become coated with solid :flatter from the steam.

x The operation of the device shown injig. 3 is similar to that already described in connection with Fig. 1. In this devicev either spraying cylinder and separator maybe shut' nolf by closing the appropriate valves for cleaning or repair without interfering with the operation of the other cylinder and separator. In washing the grids by means of valved pipe connections 82 or 83, the spraying cylinder that is being washed may be shut ott from the other by means of valves provided in thepipe connections.

The spraying chamber 85 shown in Fig. 4, is

provided with. staggered sloping overlapping trough-shaped bailles 86 extending inwardly from opposite sides of the inside walls of the chamber, so arranged that when water is sprayed through the steam it collects at the bottom of the troughshaped arrangements and is blown along with the steam from one of the trough-shaped arrangements to the next one below and made to mingle with the steam asl the steam flows downwardly through the vertical cylinder.

I claim: Y

1. In a boiler having a steam drum and a superheater, means for spraying wash water into the steam as it passes from said drum to said superheater, and separating the water from the steam before it passes into said superheater, a heat exchanger utilizing said separated waterfor heating ywash water, and a float for regulating the depth of water in said heat exchanger.

2. In a steam boiler, a superheater, means for conducting saturated steam from the steam space of said steam boiler, means for washing said saturated steam with water of greater purity than that in said boiler, means for regulating thel amount of wash water in proportion to the iiow of steam from said boiler, means for separating the excess water from said steam, means for removing the excess water so separated from the steam, and means for delivering the cleaned steam said superheater, i

3. In a steam boiler, a superheater, means for conducting saturated steam from the steam space of said steam boiler, means for washing said saturated steam with water 'of greater purity than that in said boiler, means for separating the excess water from said steam, means for removing the 'excess water so separated from the steam, means for delivering the cleaned steam to said superheater, and means for heating said wash water by the excess water removed from the steam.

4..Inaboiler havingasteamdrumanda superheater, means for spraying wash water into the steam as it passes from said drum to said superheater, and separating the water from the steam before it passes into said superheater, and a heat exchanger utilizing said separated water for heating the wash water.

5. In a boiler having arsteam drum and a superheater, means for spraying wash water into the steam as it passes from said drum to said superheater, and separating the water from theA jsteam before it passes into said superheater, a' heat exchanger utilizing said separated water .for heating the wash water, and means for regulating the depth of water in said heat exchanger.

A6. In combination with a steam boiler and 'superheater, means interposed between the two for removal of solids from wet steam and ineluding means contacting water'of greater purity than the boiler water with the wet steam in washing relation `whereby only purified steam is delivered to the superheater, and means regulating the wash water supplied in accordance with the boiler load.

7. The' lmethod of operating a steam boiler and superheater with a steam washing device for removing solids, which comprises contacting water, of greater purity thanthe boiler water with wet steam in washing relation before the ,steam enters the superheater, and regulating the amount of water so contactedA in accordance with the boiler load.

8. The method of Areducing the solid concentration of wet steam containing-solids in solution 150 n the suspended moisture which comprises passing substantially all of the wet steam through a steam space in an intimate and substantially uniform contact with water of less solid concentration than the suspended moisture suflicient to substantially lower the solid concentration of the suspended moisture, and subsequently subjecting the treated steam to a steam and moisture separating action.

9. The method of reducing the solid concentration of wet steam containing solids in solution in the suspended moisture which comprises passing the wet steam through asteam space and diluting the water solution of solids forming the

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