US1941422A - Vacuum producing and heating apparatus - Google Patents

Description

Dec. 26, 1933. J. H. WALKER 1,941,422

VACUUM PRODUCING AND HEATING APPARATUS Filed June 20. 1932 gwuc/wkwl Jaw? as A- 772M 19)" Patented Dec. 26, 1933 UNITED STATES PATENT OFFICE VACUUM PRODUCING AND HEATING APPARATUS Application June 20, 1932. Serial No. 618,351

Claims. (Cl. 257-30) This invention relates generally to water heaters and has for an object the provision of means for utilizing the heat from steam used in conjunction with vacuum producing devices operated by steam, such as steam ejector cooling systems, for heating to a suitable temperature the water discharged from said systems.

Another object is to provide a plurality of ejectors which draw from the same vacuum tank 15 and discharge into the condensing means.

Another object is to provide a heater wherein automatically operable means is provided for regulating the amount of steam used for heating the water.

Another object is to provide a heater wherein provision is made for utilizing the heat from condensation from part of the system for stepping up the temperature-of the water while it is flowing from one part of the system to another.

Another object is to provide a heater wherein the flow of water from one part of the system to the other is interrupted and directed elsewhere when the flow of water through the other part falls below a predetermined point.

Other objects, advantages and novel details of construction of this invention will be made more apparent as this description proceeds, .especially when considered in connection with the accompanying drawing, wherein:

The figure illustrated is a diagrammatic view of vacuum producing equipment and a heater embodying my invention.

Referring now to the drawing, A is the vacuum tank; B is the pump; C is the cooling unit; D are v the spray nozzles; E is the steam ejector and F is the condenser of a conventional form of steam jet cooling system. A very high vacuum or a very low absolute pressure is maintained in the tank A, preferably by means of the steam ejector E which is connected to the tank by piping G and discharges into the condenser F. If the temperature of the water sprayed into the tank A from the nozzles D is above the temperature corresponding to the pressure maintained in the tank,

then a part of the water will flash into vapor. The heat required to vaporize this amount of water will be supplied by the remainder of the water flowing through the system and the giving up of this heat results in a lowering of the water temperature to a point corresponding with the pressure existing in the tank. For example, if the pressure in the tank is maintained at 0.1475 pounds per square inch absolute, the water will be cooled to approximately 45 F. If the pressure in the tank is maintained at 0.1217 pounds per square inch absolute the water temperature will be reduced to approximately 40 F. This relation between the pressure and temperature is well known. The cold water in the tank A is withdrawn by the pump B and circulated through the cooling unit C which may consist of a coil of tubing located in the path of air which is to be cooled. The water leaves the unit C at an increased temperature of say 50 F. and passes thence to the spray nozzles D aforesaid. Water preferably having a temperature of about F. is supplied to the headers H of the condenser F and after being heated within the condenser tubes I is discharged through headers J at a temperature of approximately 95 F.

The amount of steam used by the ejector E is an appreciable factor in the operating cost and heretofore the heat in that steam was largely wasted. However, in the present instance, such waste of heat is avoided by the utilization of all or a part thereof to heat water which may be used for various purposes. In accordance with my invention I have added a second ejector K and a second condenser L which are preferably essentially similar to ejector E and condenser F respectively. As shown in the drawing, the ejectors K and E are arranged to operate in parallel, that is, so that each ejector has its suction side connected to the vacuum tank so as to draw therefrom and the steam jet E, as shown, ordinarily will have a greater vacuum producing effect than the jet K. Thus part of the work in evacuating the flash tank A may be accomplished by means of the ejector K and a portion of the water which has been heated to a temperature of say 95 F. in condenser F is heated further in its passage through condenser L to a temperature of approximately 140 F. so that it can be used in lavatory fixtures, dishwashing apparatus or for industrialpurposes. In order to obtain the temperature of 140 F. at the outlet M of condenser L the pressure of steam surrounding the tubes N in that condenser must be at a pressure corresponding to a temperature of approximately 150 F. This pressure is 3.716 pounds per square inch absolute and is higher than the pressure maintained in condenser F which may be approximately 1.100 pounds per square inch absolute. The exact values of these pressures and temperatures are not important but the significant point is that the pressure-in condenser F is maintained as low as possible for the sake of economy, whereas the pressure in condenser L must be higher.

Preferably the ejectors K and E are controlled so that ejector K is in use only when its exhaust steam can be economically utilized for water heating. For instance, when no steam is required at the moment to heat water, ejector K will be cut off and ejector E used alone since its economy as to steam consumption is much better than that of ejector K. As shown, ejector E is controlled by a thermostatic element 0 within the tank A and actuated by the temperature of the water therein, while the ejector K is controlled from a thermostatic element R located in the pipe S leading from the outlet M of the condenser L to the points of use. Thus when the temperature of the water in the tank A is lowered to a predetermined degree the ejector E will be automatically cut out of service, and when the temperature of the water flowing through the pipe S drops below a predetermined point ejector K will come into action. As a result ejector K will be utilized only when its exhaust steam is needed to heat water and the temperature of the water in the tank A will be automatically maintained.

In order that the heat in the condensation from condenser L may be removed before that condensation is wasted, I preferably utilize a heat exchanger T in the system. As shown, this exchanger comprises a casing U that receives water from the header J of condenser F and a coil V located within the casing U and adapted to receive the condensation from condenser L. T is a waste pipe leading from the coil V. Thus with this construction the heat from the condensation in coil V will be utilized to heat the water in casing U from a temperature of approximately 95 F. which it has when it leaves header J of condenser F to a temperature of approximately 110 F. before it enters condenser L. In this manner the temperature of the water is effectively stepped up while flowing between the two condensers F and L respectively.

Inasmuch as the demand for hot water in the pipe S is often intermittent, whereas the flow of water through condenser F must be continuous to give a continuous cooling effect in the tank A, I have provided a relief valve W in the pipe X extending between the condenser F and heat exchanger T. Preferably this relief valve W is so designed that when the flowof water through condenser L to pipe S falls below a predetermined point the relief valve will open and permit a suflicient quantity of water to pass through condenser F to the overflow or waste pipe Z.

Thus from the foregoing it will be apparent that I have provided a very emcient means for utilizing the heat heretofore wasted in steam ejector cooling systems for heating water. The parts are so constructed that the steam ejector cooling system maintains its high degree of emciency and at the same time steam will be used for heating purposes only when needed.

What I claim as my invention is:

1. The combination with a steam ejector cooling system including a flash tank, a condenser, and a steam ejector connected to said tank and discharging into the condenser, of a second contors aforesaid including thermostats associated with the flash tank and piping aforesaid.

2. The combination with a steam ejector cooling system including a vacuum tank, a condenser, and a steam ejector connected to said tank and discharging into said condenser of -a second condenser connected to and adapted to receive water from the first condenser, a steam ejector connected to the vacuum tank and discharging into the second condenser whereby water therein may be heated to a suitable temperature, and means between said condensers for stepping up the temperature of water discharged from the first mentioned condenser before it reaches the second mentioned condenser.

3. The combination with a steam ejector cooling system including a vacuum tank, a condenser, and a steam ejector connected to said tank and discharging into said condenser associated therewith, of a second condenser adapted to receive water from the first condenser, a steam ejector connected to said vacuum tank and discharging into the second condenser whereby water therein may be heated to a suitable temperature, means for conducting water from the first mentioned condenser to the second mentioned condenser, and means associated with the second mentioned condenser and the means just mentioned for stepping up the temperature of the water from the first mentioned condenser before it reaches the second mentioned condenser.

4. The combination with a steam ejector cooling system having a condenser and a steam ejector associated therewith, of a second condenser for receiving water from the first mentioned condenser, a steam ejector associated with the second condenser whereby water therein may be heated to a suitable temperature, and piping for conducting to a suitable point the water heated in the second condenser, means for conducting water from the first mentioned condenser to the second mentioned condenser, and relief means associated with the last mentioned means and operable to cut ofi the flow of water from the first mentioned condenser to the second mentioned condenser and to permit water from the first mentioned condenser to be otherwise directed when the flow of water through the piping aforesaid from the sec-. ond condenser falls below a predetermined point.

5. In a device of the class described, a vacuum tank, a pair of condensers arranged in series, and a pair of steam ejectors arranged in parallel with reference to the vacuum tank aforesaid and discharging into said condensers.

6. In a device of the class described, a vacuum tank, a pair of condensers, a pair of steam ejectors discharging into said condensers, one into each condenser, and a conduit leading from the tank and common to both of said ejectors.

7. In a device of the class described, a pair of condensers, means for conducting a fluid through said condensers, means including a steam ejector discharging into one of said condensers for heating the fluid in said conducting means, means associated with said conducting means for stepping up the temperature of the fluid after it reaches the first mentioned condenser and before it reaches the second mentioned condenser, and means including a steam ejector discharging into the second condenser for heating the fluid in said conducting means after the temperature thereof has been stepped up.

8. In a device of the class described, a vacuum tank, a condenser, a steam ejector discharging into said condenser, a second condenser, a steam means connecting the suction sides of the ejectors with the tank, and control means for said ejectors including means for shutting off one of them without interfering with the operation of the other. 4

9. In a device of the class described, a vacuum tank, a condenser, means including a steam ejector for heating fluid in said condenser, a second condenser, means for conducting the heated fluid from the first condenser to the second condenser, means including a second steam ejector for heating the heated fluid in the second condenser, piping for conducting to a suitable point the heated fluid from the second condenser, means connecting the suction sides of the ejectors with the tank, and control means for the ejectors associated with the tank and piping.

10. In a device of the class described, a vacuum tank, a condenser, means including a steam ejector for heating fluid in said condenser, a second condenser, means for conducting the heated fluid from the first condenser to the second condenser, means including a second steam ejector for heating the heated fluid in the second condenser, piping for conducting to a suitable point the heated fluid from the second condenser, means connecting the suction sides of the ejectors with the tank, and means associated with the conducting means aforesaid and operable to cut off the flow of fluid from the first condenser to the second condenser when the flow of fluid through the piping aforesaid falls below a predetermined point.

11. In a device of the class described, a vacuum tank, condensing means, a pair of steam ejectors connected in parallel and discharging into said condensing means, and means connecting the suction side of said ejectors to said vacuum tank.

12. In a device of the class described, a vacuum tank, a pair of condensers, a pair of steam ejectors discharging in parallel into said condensers, one into each condenser, and means connecting the suction sides of said ejectors to said vacuum tank.

13. In a device of the class described, a vacuum tank, a pair of condensers, a pair of steam ejectors-discharging into said condensers, one intoeach condenser, and means leading from the tank to said ejectors. v

14. In a device of the class described, a vacuum tank, condensing means, and a plurality of steam ejectors discharging into said condensing means, the suction sides of said ejectors being connected to and drawing from said vacuum" tank.

15. In a device of the class described, a vacuum tank, a pair of condensers, and a pair of steam ejectors discharging in parallel into said condensers, one into each condenser, the suction sides of said ejectors being connected to and drawing from said vacuum tank.

JAMES H. WALKER.

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