US1640748A - Progressive condenser - Google Patents

Description

Aug. 30, 1927. 1,640,748

C. F. BRAUN PROGRESSIVE CONDENSER Filed Feb. 7, 1923 2 Sheets-Sheet 1 Gmwzd Le wL [NV/swim CARLE BRAl/LN.

ATT ORA/[X51 Aug. 30,1927. 1,640,748

- c. F. BRAUN PROGRES S I VE CONDENSER Filed Feb. '7, 1923 2 Sheets-Sheet 2 Patented Aug. 30, 1927.

UNITED STATES CARL IF. BRAUN, OF PASADENA, CALIFORNIA.

PROGRESSIVE CONDENSER.

Application filed February '7, 1923.

This invention relates to fractionating condensers and the like, of the type shown in my copending application entitled Fractionating condensers, Serial No. 522,327, and filed December 14., 1921.

In the operation of most fractionating condensers of the above mentioned type, experience has proven that their efficiency is limited due to the fact that there is not a proper ratio of dephlegmating or re-evaporation surface to the condensing surface. and that the condensate is very often objectionably cooled before re-evaporation is brought about, and it has further been demonstrated that the distribution and flow of the con densate over and along the dephlegmating surfaces is not uniform or constant. With these defects in mind it is the object of the present invention to provide a fractionating condenser within which there is an efficient ratio between the condensation and dephlegmation surfaces, and a uniform distribution of the condensate without its becoming objectionably cooled prior to dephlegmat-ion, thus insuring the recovery of desired fractions of a fluid while eliminating the unclesired fractions.

The present invention contemplates the use of a tube nest through which a cooling medium is circulated. said nest being inclosed within a shell through which vapors are passed and within which their progressive condensation is brought about, the tube nest embodying the use of a plurality of dephlegmating surfaces properly distributed over the sectional area of the shell and in such relation to the tubes as to insure a uniform dephlegmation of the condensate, without objectionable cooling, and a direct, and, to a large extent, roportionate condensing and dephlegmating surface.

The invention is illustrated by way of example in the accompanying drawings, in which:

Fig. 1 is a central longitudinal section through the progressive condenser showing the arrangement of the tube nest and the direction of flow of the vapors and condensate.

Fig. 2 is a view in transverse section through the condenser showing the construc tion and arrangement of the cooling tubes and thedephlegmating surfaces.

Fig. 3 is an enlarged fragmentary view showing the details of one of the dephlegmating pans.

Serial No. 617,492.

Fig. 4: is a fragmentary view in perspective showing the relative positions of a baffle plate, a detlegmating plate, and cooling tubes associated therewith.

Referring more particularly to the drawing. 10 indicates the shell of afractionating condenser which is provided at its opposite ends with heads 11 and 12. The shell provides a housing for atube nest 13. the tube nest having end tube sheets which are secured between the outer ends of the shell and the heads. The heads provide inlet and outlet chambers for a cooling medium which is circulated through the tubes, an induction pipe 14 being connected with head 12 and an eduction pipe 15 being connected with the head 11. A. counter circulation of vapor is brought about by admitting vapor to an intake nozzle 16. after which the vapors which have not been condensed pass from the shell through an exhaust nozzle 17.

It is understood that the vapors entering the shell through the nozzle 16 are at a relatively high temperature. and that as they come into contact with the cooling surfaces of tubes 18 of the tube nest they will be partially condensed, that is. fractions of the vapors which are cooled to their critical point of condensation will be condensed, and it is therefore desirable to insure that all of the vapors will reach these points as directly as possible and to require minimum re-evaporation and subsequent condensation. With this idea in view the tube nest is arranged'with a plurality of rows of tubes which preferably extend horizontally, or nearly so, and with rows superposed. The tubes are systematically arranged relative to dephlegmating surfaces, which surfaces are provided by dephlegmating pans 19. more specifically shown in Figs. 3 and 4 of the drawings. These surfaces are formed by pans which extend longitudinally of the tube nest and are arranged in horizontal planes, or preferably on a slight incline as indicated by the ground level line in Fig. 1, while being interposed between rows of tubes.

As shown in Fig. 2 of the drawings, two rows of tubes are disposed above a set of dephlegmating pans. while in Fig. 3 a single row is shown. In theory it is highly desirable to design the condenser so that the cooling surface area of a given set of tubes will be equal to the dephlegmating surface of the pans directly below said group of tubes. This will insure that a maximum progressive condensation will take place without re-evaporation of the condensate, for when the condensate is required to fall. over a large number of tubes, it will be unduly cooled, and the dephleginating surface will not be adequate to properly accommodate it and present it for further evaporation. By the use of alternate rows of the tubes and dephleglnating surfaces of approximately equal surface areas a very close and ellicient fractionation will be brought about. If, however, this accurate result is not necessary, two or more rows of tubes may be utilized for each set of pans, as, for example, the arrangen'lent shown in Fig. 2.. I In any event all otthe dephlegniating surface will be surrounded by vapors, and as this surface consists of thin sheets of metal which will readily respond to temperature changes, heat will be readily transmitted from the vapors passing over the bottom of the surface to the condensate on top of the surface of the pans. The condensate will also be directly heated from contact with the vapors passing along and above the dephlegmating surface, while none of the de phlegmating surfaces are in' contact with cooling surfaces or atmospheric air.

In order to insure that the dephlegmating surfaces will be uniformly covered with condensate, andthat there will not be a tendency for the condensate to drain off from the sides of the depl'ileginating pans, lon gitudinal corrugations are formed in the pans andare arranged in spaced relation to each other. As shown. in Fig. 3, these corrugations are substantially in the form of ll-shaped ribs which project above the surface of the dephlegmators. Further 1111iformity of action is brought about due to the fact that the dephleginating pans and cooling tubes, pass through a series of'trans verse bafiie plates, which are preferably arranged in equal spaced relation to each other throughout the length of the tube nest. This gives turbulence to the vapors and insures that they will come into intimate contact with the cooling surfaces of the tubes and the dephlegmating surfaces of the pans.

In operation of the present invention it is desirable that the condenser shall be on a slight inclination, while extending horizontally. A condensate outlet space is provided between the-lowermost ends of the dephlegmating pans and :the adjacent "cc of an end tube sheet. Attention is directed to the fact that the dephlegmating pans extend across the throat of the condensing outlet nozzle 21, thereby insuring that prac ly none of thecondensate will pass from the condenser without first passin over de I phlegmating surfaces. ll hen the condenser is assembled as shown in Fig. 1, vapors to be condensed are drawn in through nozzle 16 and travel the'length ofthe shell 10 to the outlet nozzle 17. During this travel the vapors encounter the transverse bali'le plates 20 and are caused to be distributed around and along the cooling tubes and dephlegmating pans in a uniform manner through openings l8, l8, and 19. At this time the vapors will impart heat to the dephlegmating pans which they surround and will also be cooled by surrounding the tube through which a cooling medium is circulated in a counter direction. As the vapors encounter the tubes and when their condensation temperature has been reached the fractions will condense and drop onto the dephlegmating pans. Here they will gradually flow toward the low end of the condenserand will thereafter drain off through the condensate outlet 21. and a liquid trap connected there to and indicated by dotted lines in Fig. 1 of the drawing. During this flow dephlegmation of the condensate will take place, thus re-evaporating vapors of lighter fractions which have been absorbed by condensate of the heavier fractions, which lighter fractions it is desired to pass from the vapor outlet as vapors. This insures that condensa tion or absorption of all. undesired fractions carried by the vapors as the vapors flow through the condenser will be minimized. This action isparticularly brought about due to the fact that there is such a uniform distribution and arrangement of cooling and dephlegmating surfaces.

It will thus be seen that by employing the apparatus here disclosed and carrying out the method hereinbefore indicated, a minimum condensation of all undesired fractions of vapors passing through a condenser may be brought about in a uniform manner; i

-While l have shown the preferred form of my invention as now known to me, it will be understood that various changes might be made in the combination, construction and arrangement of parts by those skilled in the art, without departing from the spirit of the inventionas claimed.

Having thus described my invention, what I claim and desire to secure by Letters Patent is: p

1. A method'of condensation which consists in passing vapors longitudinally over and around cooling and dephlegmatingsun faces of substantially equal surface areas.

2. A method of progressive condensation which consists in passing, vapors longitudir nally over and around cooling and dephleg mating elements having a predetermined ratio of surface area to insure maximum condensation of the vapors.

3. A progressive condenser comprising .ashell,a tube nest extending longitudinally therein, connections at the ends of the shell for passing vapors through the shell along and around the tubes therein, connections at the opposite ends of the tube nest for passing a cooling medium therethrough and a plurality of substantially horizontally extending dephlegmating pans dividing the tubes into relative small groups, the surface area of the groups of tubes and the surface area of the pans disposed beneath the same being in predetermined ratio to each other.

4. A progressive condenser comprising a shell, a tube nest extending longitudinally therein, connect-ions at the ends of the shell for passing vapors through the shell along and around the tubes therein, connections at the opposite ends of the tube nest for passing a cooling medium therethrough and a plurality of substantially horizontally extending dephlegmating pans dividing the tubes into relative small groups, the surface area of the groups of tubes and the surface area of the pans disposed beneath the same 20 being substantially equal.

CARL F. BRAUN.

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