US1674024A

US1674024A - Boiler system

Info

Publication number: US1674024A
Application number: US617997A
Authority: US
Inventors: Schroeder Bernhard; Charles U Savoye
Original assignee: Babcock and Wilcox Co
Current assignee: Babcock and Wilcox Co
Priority date: 1923-02-09
Filing date: 1923-02-09
Publication date: 1928-06-19
Anticipated expiration: 1945-06-19

Description

B. SCHROEDER ET AL BOILER SYSTEM June 19, 1928. 1,674,024

Filed Feb. 9, 1923 2 Sheets-Sheet l INVENTORS 6d ATTORNEY June 19, 1928. 1,674,024

B. SCHROEDER ET AL BOILER SYSTEM Filed Feb. 9, 192.5 2 Sheets-Sheet 2 INVEN 0R -41 ATTORNEYS Patented June 19, 1928.

.UNITED STATES PATENT OFFICE.

IBERNHARD sonnonnna, or CHICAGO, ILLINOIS, Ann CHARLES U. sAvoYn, or

HACKENS ACK, NEW JERSEY, ASSIGNORS TO THE BABCOCKKF. WILCOXCOMPANY, OF BAYONNE, NEW JERSEY, A CORPQRA'IIQI-I OF NEW JERSEY.

BOILER sYs'rEM;

Application filed February 9, 1923. Serial No. 617,997. I

The present invention relates to boiler systems in which it is desirable to remove air and gases from the boiler water to prevent corrosion of the metal parts of the boiler 5 system.

The invention will be best understood from the following description and the annexed drawings, in which Fig. 1 is an elevation, partly in section, of an apparatus 10 embodying our invention, Fig. 2 is a section on the line 22 thereof, looking in the di rection of the arrows, and Fig. 3 is a diagrammatic view illustrating the closed circuit to which the surge tank is connected.

Like reference characters indicate like parts in the different views.

Boiler systems, particularly those having economizers which are liable to corrosion from the oxygen in the feed water, preferably should be operated on what is substantially a closed cycle; that is to say, the steam, after passing through the prime movers, should be condensed and the condensate pumped back into the boilers without expo sure to the atmosphere. It will be obvious that in such a system, the water when once freed of air would not be recharged with air, so long asthe system continued to opcrate. losses which must be made up and a supply of make-up water is provided to this end, and

this make-up water necessarily carries into the system the air or gases with which it is charged and these gases are liable to corrode the economizers.

It is also found in practice that the demands of the feed pumps which, in turn, are controlled by the water levels in the boilers, are not constant, due to variations in the op erations of the plant. so that at timesthe supply of condensate is greater than the water which is to be pumped into the boilers, and at other times is insufficient to supply the demands of the pump. Here again, if the excess water is exposed to the atmosphere, oxygen and other gases will be absorbed, so that when this excess is again fed to the economizer and boilers, the gases will be again carried into the system.

In Figs. 1 and 2 is illustrated an arrangement for'obviating these difiiculties, such device being used in connection with a system operating on a closed cycle and with a make-up water supply and also with pro- In practice, however, there are water vision for taking'care of excess condensate or for supplying the necessary make-up water in the event that the condensate is'insufiicient to meet the demands of the boilers.

In the arrangement illustrated in Fig. 1, the pipe 10 is the carrier of the condensate from the condensers to the feed pumps, the water flowing down through the pipe'10 and out of the pipe 11 to the feed pumps. A

T 12 in the pipe 10 communicates through a pipe 13 with a tank 14 which is opened to the atmosphere through a pipe 15at-its top.

The pipe 13 enters the tank 14 well toward the bottom of the tank. At the upper part of the tank is a make-up water inlet 16 havmg a float-controlled valve 17 which delivers water to a distributing pan 18. An overflow pipe 19 is connected to the tank 14, so that when the tank becomes too full, the surplus water will flow over the plate 20 and out of the pipe 19 to any proper storage receptacle.

A steam pipe 21 supplies steam to a series of perforated pipes 22 in the bottom of the tank 14. The steam flow through the pipe 21 is controlled by a regulating valve 23 controlled, in turn, by a thermostat 24 which may. have an expansible fluid by which the changes in pressure therein, due to changes of temperature in the water in the tank. 14, will be transmitted through the pipe 25 to the valve 23 to control the supply of steam through the pipe 21.

Referring now to Fig. 3 in which we have boiler, the steam and water drum of which is connected by a pipe 27 to a turbine 28, the exhaust from which is conducted to a condenser 29. The condensate from the condenser is forced by a pump 30, through the pipe 10, 11, and a pump 31 forces the water through a pipe 32 and the high pressure stage 33 of an econoinizer back to the boiler. A low pressure 6001101111291 34: is alsoillustrated connected by pipes'35 and 36 to the pipe 10, on opposite sides ofa valve 37 there in, the

pipes

35 and 36 preferably being pro vided with

valves

38 and 39. By closing the

valves

38 and 39 and opening the valve 37, the low pressureeconomizer is disconnected from the system. By opening

thevalves

38 and 39 and closing the valve 37, the water is forced by the pump 30 through the low pressure economizer.

illustrated the closed circuit,26 is a steam- In operation, the tank 14 will serve to receive any difl'e're'i'ices in the water flowing through the pipes 10 and 11 or will supply water to make up such differences. For instance. it the condensate flowing into the pipe 10 is greater in amount than that required from the pipe 11. the water will back up into the tank 1d, any excess passing over the plate 20 and out of the overflow pipe 19. Similarly, if the supply of the pipe 10 is insullicient to provide enough water through the pipe 11 in accordance with the demands of the boiler, this difference is made up through the pipe 13. In other words, the pipe 13 and the tank 14 will take care of the surges in the water supply system.

ll", in operation, the water stored in the tank 14 is drawn on so that its level falls below a predetermined point, then the float valve 17 will he opened and the make-up water will flow from the pipe 16 until the level in the tank H is restored. It is this make'up water particularly which would carry air into the system. and we therefore provide the pipes 22 by which live steam may be passed into the water in the tank 14 to raise its temperature preferably to a point near the boiling point so as to drive elf the air and gases through the outlet 15. The quantity of 'ater in the ta'k let is, of course. comparatively small. so that the amount of heat required to raise this small quantity of water will be almost negligible, and yet such heat will be applied at a point where it will be most eliicient in removing the-air.

Even it no make-up water is to be heated to drive off the air and gases therefrom, nevertheless it is desirable to heat the water in the. surge tank 1% to near the boiling point. so that such water will not come into contactwith the atmosphere. The heating means raises the temperature of the water suliiciently to cause vapor to be driven oli through the ventpipe. thereby preventing air from the atmosphere entering the surge tank.

Furthermore, since the amount of water in the tank 14 is small compared with the total amount of feed water passing through the pipes 10 and 11, the temperature of the feed water is raised only slightly by the small amount of water heated in the tank 14. Consequently. the feed water is supplied to the ec'onomizer cool enough to permit. the economizer to operate efliciently.

The; thermostat 24 will maintain the temperature of the water in the tank 14 at approximately the desired temperature which will be selected so as to drive ofi' the desired percentage of the air and gases with the least expenditure of heat.

It will be obvious that, by our invention, we provide means by which the surges in the supply will be taken care of Without exposing the water to the atmosphere, and by which any make-up water will be freed from air or gases before passing into the system and, at the same time, accomplishing this with a minimum expenditure. of heat and a minimum raisingol' the tei'iiperture of the teed water.

It will be understood that the flpplltillltil'l of our invention may be widely varied. The heat may be supplied to the water in the tank 14 in any other desired manner, though we find that the direct condensation of live steam in the water is ellicient for our purpose.

id e claim:

1. In a boiler plant system having a closed circuit including a. condenser and boiler feed pump. a surge tank outside the said circuit but connected thereto between the said condenser and said feed pump to receive and supply condensate from and to the system to compensate for temporary increases and decreases of the supply of condensate as compared with the demands of the pump, a make-up water connection into the tank, means to regulate the flow of ma ke-up water into the tank in accordance with the level oi the water therein, and means for removin; gases from the water in said tank.

2. In a boiler plant system having a closed circuit including a condenser and boiler teed pump, a surge tank outside the said circuit but connected thereto between the said condenser and said 'l'eed pump to receive and supply condensate from and to the system to compensate for temporary incre: res and decreases of the supply of condensate as compared with the demands of the pump, the connection between the system and the tank being" below the normal water level in the tank, a make-up water connection into the tank. means to regulate the flow of make-up water into the tank in accordance with the level of the water therein. and means for removin gases from the water in said tank.

3. In a boiler plant system havinga closed circuit including a condenser and boiler teed pump, a surge tank open to the atmosphere and outside the said circuit but connected thereto between the said condenser and said teed pump to receive and supply condensate from and to the system to compensate for temporary increases and decreases of the supply of condensate as compared with the demands of the pump, a make-up water connection into the tank. means to regulate the flow of make-up water into the tank in accordance with the level of the water therein, and means to heat the water in the tank to remove air and gases therefrom.

at. In a boiler plant system having a closed circuit including; a condenser and boiler feed pump, a surge tank open to the atmosphere and outside the said circuit but connected thereto between the said condenser and said t'eed pump to receive and supply condensate from and to the system to compensate for temporary increases and decreases of the supply of condensate as compared with the demands of the pump, a make-up water connection into the tank, means to regulate the flow of make-up water into the tank in accordance with the level of the water therein, and means to heat the water in the tank to a predetermined temperature to remove air and gases therefrom.

5. In a boiler plant system having a'closed circuit including a condenser and boiler feed pump, a surge tank open to the atmosphere and outside the said circuit but connected thereto between the said condenser and said feed pump to receive and supply condensate from and to the system to compensate for temporary increases and decreases of the supply of condensate as compared with the demands of the pump, a make-up water connection into the tank, means to regulate the flow of make-up water into the tank in accordance with the level of the water therein, means to pass live steam into the Water in the tank to heat it to remove air and gases therefrom and a thermostat in the water to control the flow of live steam to maintain the water at a predetermined temperature.

6. In a boiler plant system having a closed circuit including a condenser and boiler ieed pump, a surge tank. open to the atmosphere and outside the said circuit but connected thereto between the said condenser and said feed pump to receive and supply condensate from and to the system to compensate for temporary increases and decreases of the supply of condensate as compared with the demands of the pump, and means to heat the water in the tank to prevent the absorption of air and gases by the Water in the tank. 7 7. In a boiler plant system havinga closed I circuit including a condenser and boiler feed feed pump to receive and supply condensate from and to the system to compensate for temporary increases and decreases of the supply of condensate as compared with the demands of the pump, and means to heat the water in the tank to a predetermined temperature and to maintain it at such temperature to prevent the absorption of air and gases by thewater in the tank.

8. In a boiler plant system having a closed circuit including a condenser and boiler feed pump, a surge tank of relatively small size compared to .the volume of the feed water and open to the atmosphere, said surge tank being located outside the said circuit but connected thereto whereby said tank is adapted to receive and supply condensate from and to the system to compensate for temporary increases and decreases of the supply of condensate as compared with the demands of the pump, said connection being at the lower part of the tank, a make-up Water connection into the tank, means to regulate the How of make-up water into the tank in accordance with the level of the water therein, and means to heat the Water in the tank to a predetermined temperature and to maintain it at such temperature to drive off the air and gases from the water and to prevent the absorption of air and gases by the water in the tank.

In a boiler plant system having a closed circuitincluding a condenser and boiler feed pump, a surge tank outslde the said circuit but connected thereto between the said condenser and said feed pump to receive and supply condensate from and to the system to compensate for temporary increases and decreases of the supply of condensate as compared with the demands of the pump, a make-up water connection into the tank, means to regulate the flow of makeup water into the tankin accordance With the level of the water therein, and means for preventing the absorption of air in the water in said surge tank.

BERNHARD SCHROEDER. CHARLES U. SAVOYE.