US1824627A - Superheater - Google Patents

Description

Sept. 22, 1931. c. U. SAVOYE SUPERHEATER Filed Feb. 28. 1930 Patented Sept. 22, 1931 UNITED STATES PATENT OFFICE CHARLES U. SAVOYE, OFHACKENSACK, NEW JERSEY, ASSIGNOR TO THE BABCO CK & WILCOX COMPANY, OF BAYONNE, NEW JERSEY, A CORPORATION OF NEW JERSEY SUPERHEATER Application filed February 28, 1930. Serial No. 431,998.

This invention relates to superheaters and more particularly to an arrangement for controlling the metal temperature of superheater tubes and tube connections during starting up periods.

In modern boiler furnaces combustion is ,so rapid and intense that, when a given boiler is being started up, the metal temperature of the superheater is raised to a high degree before sufiicient steam to keep such temperature within the desired limit is enerated.

in object of this invention is'to provlde an improved mechanism for controlling the metal temperature of a superheater during the starting up periods.

A further object is to provide an arrangement for water cooling the superheater tubes and tube connections during the starting up period, so constructed and arranged as to permit the blowin out of all water from the superheater be ore the boiler is cut into the main steam line.

These and other objects which will be apparent to those skilled in this particular art are accomplished by means of theiinvention illustrated in the accompanying-drawings in which.

Fig. 1 is a transverse sectional view, somewhat diagrammatic in character, illustrating. a steam boiler and superheater provided with a water circulating mechanism constructed in accordance with one embodiment of this invention and Fig. 2 is a partial view similar to Fig. 1 illustrating a modification.

The particular embodiments of the present invention which have been chosen for the purpose of illustration are shown in connection with the boiler setting including a steam and water drum 5 connected by the usual nipples 6 with downtake headers 7 connectedby an upper bank of steam generating tubes 8 with uptake headers 9. Steam and water circulators 10 connect the uptake headers 9' with the-steam space of the drum 5. A lower bank of steam generating tubes 11 connect downtake headers 12 and uptake headers 13. The headers 12 and 13 for the lower bank are connected by nipples 14 and 15 with the headers 7 and 9, respectively, of the upper bank as is well known in the art. As illustrated, an interdeck superheater 16 is located in the space between the upper and lower banks of tubes and the superheater tubes are associated with inlet and outlet headers 17 and 18 respectively. The usual connection 19 connects the steam space of the drum 5 with the superheater inlet header 17.

In order to provide means for preventing overheating of the superheater tubes during starting up periods, I provide an arrangement for connecting the superheater parts into the water circulation system of the boiler and arrange the connections so that either natural or forced circulation can be employed for causing water to flow through the superheater during such periods. This is accomplished by connecting the inlet header 17 with the water space of the boiler and the outlet header with the steam and water drum. Atthe same time, means is provided for effectively removing all water from the superheater parts prior .to the time the boiler is cut in on the main steam line.

As illustrated, the usual water box 19 is connected to the lower end of the downtake headers 12 for collecting sediment and the usual blowoff connection 20 having blow of! valves 21 is provided. The blow down connection 20 is connected by a line 22 with inlet headers 17 of the superheater, a valve -26 with the pipe 22 below the valve 23.

As illustrated in Fig. 1 a siphon arrangement including an ejector 29 is associated with the line 25 for providing a forced flow of water through the superheater when desired. A valved connection connecting the ejector with anydesired source of steam is provided for operating the ejector so as to accelerate flow through the line 25. A valve 31 is located in the line 25 between the ejector 29 and the steam and water drum.

In the arran ement illustrated in Fig. 2 a forced flow of water through the superheater is obtained by means of a water circulator 32 located in the line 22 connecting the blow down with the superheater inlet header.

In operation, assumin that the boiler is just being started up an that, hence, there is not suflicient steam being generated to maintain the superheater temperature within the desired limit, the blow down valve21 will be opened and the valve 24.- closed. Valves 23, 26 and 31, will be opened and valve 28 closed. As a result of this arrangement, it will be apparent that a flow of Water will be provided from the water space of the boiler such as the water box 19 through pipe 22, superheater inlet header 17, superheater tubes 16, outlet header 18 and pipe 25 to'the drum 5. It is of course understood that at this period the main valve connecting the outlet header 18 with the main steam line is closed. Just before the-pressure of the boiler reaches the point at which it will deliver steam to the main steam line, the blow down valves 21 will be closed, valve 23 will be closed and valve 28 opened. When valve 31 is then closed the flow of'steam through the connection 19 and superheater 16 will blow clear all water in the superheater, the steam and water flowing out through line 27 and line 22 to the blow down connection and out through the valve 24. After the boiler is on the" line the valve 26 will be closed. By leaving the valve 28 open any leakage of water back through the valve 31 will drain out through pipes and 22 into a blow off tank and any eakage of water through the blow down valves 21 will drain out in the same manner.

During the starting up period, if the natural circulation of the water through the superheater is less than is desired, such a forced flow mechanismas the steam siphon of Fig. 1 or the water circulator of Fig. 2 can be employed for roducing a forced flow. Although I have dtscribed certain specific embodiments of thisinvention in detail it will apparent that various additions, omissions and substitutions can be made therein without departing from the spirit of this invention or the terms of the appended claims.

What I claim as new and desire to secure by Letters Patent is:

1. The combination in a steam boiler having a steam and water drum, a superheater, inlet and outlet headers, a connection between the steam space of said drum and said superheater inlet header, a valved connection between thel-water space of said drum and said inlet header, a second valved connection between said outlet header and said drum and water circulating means associated with one of saidvalved connections.

2. The combination in a steam boiler having a steam and water drum, a superheater, inlet and outlet headers for said superheater, steam generating tubes, downtake connections between said drum and said tubes, a valved connection between said downtake connections and said superheater inlet header, a valved connection between said superheater outlet header and said drum and means associated with one of said connections for providing a forced flow of water tion and said superheater inlet header, a

connection between said superheater outlet header and said drum for producin a flow of water through said superheater uring a starting up period.

I 4. The combination in a steam boiler having a steam and water drum of a superheater, inlet and outlet headers for said superheater, a steam connection between the steam space of said drum and said inlet header, a blow down connected to the water space of said boiler, a valved connection between said blow down and said inlet header, a valved connection between said outlet header and said drum and a valved by-pass between said valved connections.

5. The combination in a steam boiler having a steam and water drum of a superheater, inlet and outlet headers for said superheater, a steam connection between the steam space of said drum and said inlet header, a blow down connected to the water space of said boiler, a valved connection between said blow down and said inlet header, a valved connection between said outlet header and said drum, a valved by-pass between said valved connections and a water circulator in one of said connections.

6. The combination in a steam boiler having banks of water tubes and a cooperating receiving steam, and valved connections for providing a circulation of Water from the boiler through the superheater and to the boiler only on starting up the boiler whereby overheating is prevented.

7. The combination in a steam boiler having banks of Water tubes and a cooperating steam and water drum, of a superheater interdecked with respect to the banks of water tubes and connected with said steam and water drum for receiving steam, and valved connections for providing a circulation of Water from the boiler through the superheater and to the boiler on starting up the boiler whereby overheating is prevented.

CHARLES U. SAVOYE.

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