US2207390A - Injector heater - Google Patents

Description

July 9, 1940. i J c wHlTE v 2,207,390

INJECTOR HEATER Filed y 51, 1959 Q4 R n N N I N ENTOR. Jfzzz 0. law

RNEY,

Patented July 9, 1940 PATENT oFr-icc INJECTOR, HEATER John C. White, Madison, Wis" I I Ap l cation July 31, 1939, SerialNo. 287,450

2 Claims. Thisiinventionirelates to apparatus for heating fluids by means of steam, either live or exhaust,

and constitutes an improvement upon the heater disclosed in my Patent No. 2,066,867, issued January 5, 1937. 9

With the use of a heater such as disclosed in said patent,'the temperature of the fluid beingsteam to waterflow in the injector proper must be such as to maintain a vacuum of about 20 inches mercury at the throat of the venturi or combining tube, and any attempt to attain a final temperature above 165 F. by increasing the 'steamrelatively to the amount of water introduced will so reduce the vacuumat the throat of the venturi as to cause unstable and unsatisfactory operation.

The primary purpose of my present invention is to provide an injector heater by which the liquid being heated may be raised to a temperature considerably above the maximum of 165 F. heretofore attainable. In fact, my present invention is capable of delivering the efliuent at a temperature higher than 200 F., and in actual tests an effluent temperature of 210 F. has been attained. For certain purposes, such as milk drying and other processes, such high temperatures are very desirable, and the requirements of such methods may be met by employing an injector heater constructed in accordance with the principles of my present invention.-

While my invention is capable of many uses, it is here shown for illustrative purposes as incorporated in a heat exchange system of the general type exemplified in my prior Patent No. 2,158,809, issued May 16, 1939.

Referring to the accompanying drawing,

Fig. 1 is a perspective view of a heat exchange system embodying my improved injector heater;

Fig. 2 is a longitudinal sectional View of a heater constructed in accordance with my invention; and

Fig. 3 is a transverse sectional view on the line 33 of Fig. 2.

The system chosen for the purposes of exemplifying the principles of my invention and illustrated in Fig. 1 is similar to that disclosed in my prior Patent No. 2,158,809, and comprises a heat exchanger 4 of the double pipe type in which the outer pipes conduct the heating fluid around the inner pipes containing the fluid to be heated. A storage tank 5 supplies a constant head of water for the injector heater 6 to which the water from the tank is conducted by a pipe 1 and from which the heated water is conducted to the lowermost coil of the heat exchanger by a pipe 8.

Asteam supply line 9 carrying either live or 5 exhaust steam is provided with a thermostatie cally controlled valve H for regulating the flow of steam through the pipe I2 to the heater which heats and simultaneously propels the water through pipe 8 to the coils. The water emerges from the coils into a pipe 13 by which it is returned to the storage tank. The tank is equipped with an overflow pipe l4 and a supply pipe 15 equipped with a float controlled valve I 6. k The fluid to be heated is supplied to the heat exchanger throughpipe l1, and the flow'of heating fluid to the exchanger is controlled through a diaphragm actuated valve 18 by the flow of fluid through pipe l1. Further details of the apparatus need not be described here, as they are fully disclosed in said Patent No. 2,158,809.

- The injector heater 6, by which the'water delivered from the tank 5 through the pipe I is heated by the steam delivered to the heater from the pipe I2, comprises as shown in Fig. 2 a combining tube l9 and a delivery tube 2| having their opposed ends maintained in spaced relation by a cylindrical sleeve 22 which provides an overflow chamber from which the overflow is delivered through a pipe 23. The steam entering from pipe I2 is delivered into the intake end of the combining tube l9 through a nozzle 24 projecting through a chamber 25 to which the water is supplied by the pipe 1. The water is drawn by the injector action of the delivered steam into the combining tube, with the result that the steam and water are combined during their travel therethrough, the water being heated by absorbing the heat units of the steam and the steam being at the same time condensed. The combined flow of heated water is discharged at high velocity across the gap between tubes l9 and 2| in overflow chamber 22. Entering the delivery tube 2|, its velocity head is gradually converted to pressure head and it emerges through pipe 8 to the point of use.

The construction of the heater thus far described is similar to that disclosed in my Patent No. 2,066,867, but as previously stated, it is impossible with thisheater to attain a delivery temperature of the efiluent in excess of approximately 165 F. For the purpose of increasing the delivery temperature of the efiluentwithout detracting from the eflici-ency of the heater, my present invention contemplates further heating the eflluent by delivering steam thereto in the supply pipe 9. The steam thus supplied is drawn into the delivery tube and further heats the liquid flowing therethrough so that the temperature of the delivered efiiuent is raised from a previous maximum of F. to a temperature above 200 F. and closely approaching the boiling point of The steam supply pipes 9 and 29 are equipped with hand operable shut-off valves 3! and 32, respectively. In starting the operation, valve 32 is closed, and valve 3! is opened to admit steam .to the heater in proportions determined by the temperature controlling valve ll so as to deliver the heated, fluid to pipe 8 from the heater at a temperature not over 165 F., which is the maximum temperature at which an injector heater could normally be operated prior to my invention.

Inorder to obtain a higher temperature, the valve 32 is gradually opened admitting supplementary steam to the delivery tube through the annular passage 2! until the desired final temperature is attained. When set for the desired temperature, the system will continue to operate automatically without further attention.

The structural details of the heater may of course be varied. within considerable limits without departing from the scope of the invention as defined in the following claims.

I claim:

1. An injector heater having a Venturi passage comprising a tapered combining tube forming an intake at its larger end and a tapered delivery tube forming an expanding portion for the passage, the said expanding portion having an area of low pressure during operation of the injector, said tubes being arranged in alignment with their smaller ends adjacent to each other, an overflow chamber surrounding the adjacent ends of said tubes, means for supplying to the intake end of said combining tube the liquid to be heated and steam for heating the same, and means for introducing additional steam into the low pressure area of the expanding portion of the passage close to the overflow chamber.

2. An injector heater having a Venturi passage comprising a tapered combining tube forming an intake at its larger end and a tapered delivery tube forming an expanding portion for the passage, the said expanding portion having an area of low pressure during operation of the injector, said tubes being arranged in alignment with their smaller ends adjacent to eachother, an overflow chamber surrounding the adjacent ends of said tubes, means for supplying to the intake end of said combining tube the liquid to be heated and steam for heating the same, an annular chamber surrounding the bore of the expanding portion of said passage close to the overflow chamber and communicating with the low pressure area of the passage, and a steam supply connected with said annular chamber for introducing additional steam into the passage.

JOHN C. WHITE.

Images