US1992352A - Condenser for hydrocarbons - Google Patents

Description

Feb. 26, 1935. T. CAMERON CONDENSER FOR HYDROCARBONS Filed Sept. 11, 1953 2 Sheets-Sheet 2 Laws Z'Camemn INVENTOR ATTORNEY Patented Feb. 26, 1935 NITED STATES PATENT oFFicE Louis T. Cameron, Toledo, Ohio, assignor of onehalf to Charles 0. Marshall, Jr., Chicago, Ill.

Application September 11, 1933, Serial No, 688,883

15 Claims.

The principal object of my invention is to effect complete condensation, chilling and separa; tion of hydrocarbons from a mixture of hydrocarbon vapor with fixed gases, in such an efiicient manner that a minimum amount of cooling liquid is used.

I attain this object by a. device defined in the appended claims, two preferred embodiments of which are illustrated in the accompanying drawings, in which- Figure I is an elevational view of a condenser constructed in accordance with my invention, with part of the outer shell broken away to show the interior structure;

Figure 11 is a horizontal sectional view along the line II-II of Figure I showing diagrammatically a settling tank connected to the condenser;

Figure 111 is a horizontal sectional view along the line III-III of Figure I;

Figure IV is a horizontal sectional view along the line IVIV of Figure I;

Figure V is an elevational view of a modified form of condenser constructed in accordance with my invention with a part of the outer shell broken away to show the interior structure;

Figure VI is a horizontal sectional view along the line VI- -VI of Figure V showing diagrammatically a settling tank connected to the condenser;

Figure VII is a vertical sectional view along the line VII-VII of Figure F1, showing a fragmentary portion of the condenser of Figure V;

Figures VIII, X and XII each show a side view of an alternative form of bubble cap for use in a condenser embodying my invention;

Figures IX, XI and XIII show bottom views of the bubble caps of Figures VIII, X and XII respectively;

Figure XIV is an enlarged vertical sectional view of the check valve in Figures I, IV and V.

Similar numerals refer to similar parts thruout the several views.

The vertical cylindrical shell 12 of the condenser, illustrated in Figures I and V, is mounted on a suitable foundation and has a manhole 13 at its top, which provides access to the interior for installing, or repairing parts. At the bottom of the condenser shell 12 may be a ventilation opening 14 to supply air to the interior of the shell when a man is working therein, as during construction, or repair of the condenser. The ventilation opening 14 is covered by a cover plate 15 that may have a drain pipe 16 leading therethru, so that the shell may be drained when repairs are needed.

Welded at equal intervals up the interior of the shell are a series of horizontal rims 1'1 (see Figure VH). Upon'each of the rims I7 is bolted a circular tray 18 made in three sections to facilitate mounting in place. The three sections of each tray are bolted together by means of joining bars 19.

Passing through and projecting from the upper sides of the circular trays 18 that are mounted on all of the rims 17 except the topmost rim, are short lengths of pipe, such as boiler flue, 20. Above each of the vertical lengths of pipe 20 and resting on the tray 18 is a bubble cap 21 (see Figures VIII through mm, which may be of any'preferred shape. Guiding lugs 22 may be provided on the inner wall of the bubble cap, to fit around the vertical length of pipe 20 and maintain the bubble cap in proper position.

As it will appear from the description of the operation of the condenser, there will be gas present which can collect inside the bubble caps, Small holes 23 may be provided in the top of each bubble cap to allow rapid escape of this gas and to permit the liquid hydrocarbons to float upward to the top of the condenser after the plant 25 has been shut down instead of remaining trapped under the bubble caps. In addition, the small' holes 23 will prevent any accumulation of gas under the caps that might cause them to float and get out of position.

Another precaution against floating of the hubble caps may be provided in the form of vertical stops 24 extending from the top of each bubble cap and abutting against the bottom of the tray above, so that the bubble cap is held down. Some of the weight of the tray above may be carried on the stops 24 with a consequent better distribution of stresses throughout the tray structure. The lower rim of each bubble cap that rests against the tray is serrated, as shown-in Figures VIII through XIII.

It is apparent that in passing from tray to tray through the vertical lengths of pipe and under the bubble caps, the liquids and gases flowing through the condenser must flow between serrations in the edge of the bubble caps and become thoroughly and intimately mixed.

However, the illustrated arrangement of trays and bubble caps is but'a preferred system for mixing the liquids and gases as they pass through that goes out at the top of the condenser. The mist separator consists of two mist plates. 25, each of which is made in three parts as shown in Figures I and V, fastened together by means of joining bars 19 to facilitate assembly, the upper of which is mounted on the top surface of the rim 17. Since the upper mist plate is mounted on the top surface of the rim and the lower mist Plate is fastened to the under side of the rim a narrow space equal to the thickness of the rim is leftbetwecn the two mist plates.

In each mist plate are rows of perforations 125 for passage of the gas,"and the rows of perforations in the upper mist plate are so placed that none of the upper mist plate perforations comes opposite a perforation in the lower mist plate. Gas flowing thru the perforations in the lower mist plate will be sharply deflected before it can go thru the perforations in the upper mist plate, so that fine spraywill be thrownout of the gas by centrifugal force and deposited on the mist plates. The gas then leaves the condenser thru a gas pipe 26. There are other types of mist separators, the construction of which is: well known, that would function satisfactorily in place of the mist plate 25, if installed at any point in the flow of gas leaving the condenser.

A vapor pipe 27 conducts the mixture of gases containing the vapors to be condensed into the condenser shell near the bottom. In the end of the vapor pipe 2'7, to prevent backflow of liquid thereinto, may be provided a check valve comprising a seat 28, valve 29, and valve retaining cross piece 30, (see Figure my). Part of the bottom tray of the condenser is broken away in Figure IV to show the top of the check valve. Where the vapor pipe 27 enters the shell 12 it may be surrounded by a flange that is bolted to the shell,

so that the check valve may be readily inspected outlet pipe 32 to which, at its highest point of travel, is connected a vertical vent pipe 33 that is open at its upper end 34 to prevent siphoning filled with water up to a. point that is level with,

or somewhat higher than, the highest point of travel of the water outlet pipe 32, and that a certain amount of restriction of the flow oLwater thru the outlet pipe 32 by means of a valve will tend to raise the level of water in the condenser. In order to control the flow of water thru the water outlet pipe 32, and to assist in controlling the water level in the condenser, thereforeis provided, at the highest point of travel of water outlet pipe 32, a. valve 35. Also, connected to water outlet pipe 32, are branches 36, by-passed around the valve 35 in water outlet pipe 32, passing at progressively higher levels, and each containing a valve 37.

The water outlet pipe 32 is preferably connected so that it withdraws water at a point just above the lowest of the trays 18. To prevent hydrocarbons that have entered thru the vapor pipe 27 from flowing-directly out of the condenser thru the water outlet pipe 32, the bubble caps may be omitted from the portion of the lowest tray 18 that is adjacent to the water outlet, and this same portion of the tray may be left blank, without perforations (see Figure IV). The blank portion of this tray may be separated from the part having bubble caps by a partition plate 38.

The portion of about the next three trays that is immediately above the blankportion of the lowest tray may be separated from the rest of the condenser by a fine screen 39 such as a 60 mesh screen, which may be made in a single piece and be passed vertically thru each tray at a joint formed by means of one of the joining bars 19. Although it is then well to remove the bubble caps from the portion of the trays that is screened on from the rest of the condenser, the short lengths of pipe 20 may be left in place, as shown in Figures 1, m and V. However, they may be omitted, so that wide perforations in the plates remain in their stead.

Once the screen 39 has been wet by the water with which the condenser is filled before being put into operation, it will tend to screen out drops of condensed hydrocarbons that are formed after hydrocarbon vapors are turned in thru the vapor inlet pipe 27. Since the drops of hydrocarbon are less dense than the water they will float upward and rarely come into contact with the screen 39, particularly if a strip of each tray is left blank between the screen and the bubble caps. The condensed hydrocarbons after rising to the top of the condenser are withdrawn, together with some of the water, thru a hydrocarbon outlet pipe 40. I

The hydrocarbon outlet pipe 40, and the water outlet pipe 32 are preferably located on the same side of the condenser, while the water inlet pipe 31 and the vapor pipe 27 are preferably both located on the opposite side of the condenser. All the trays above the screen 39 and below the hydrocarbon outlet pipe 40 may be completely filled with bubble caps as shown in Figure II, each of the bubble caps covering one of the vertical lengths of pipe 20.

In the modified form shown in Figure V, the condenser shell is made longer and several trays are inserted between the hydrocarbon outlet pipe 40 and the mist plates 25. The portion of the condenser containing these trays is preferably not filled completely with water, but a pool of water should be held on each tray. Cold water may be introduced to the top tray thru an auxiliary water inlet pipe 41 and allowed to flow downward from tray to tray. The only dilference between these trays and the tray shown in Figure 11 may be in the omission of two pairs of bubble caps on opposite sides of each tray. In place of the bubble caps the two spaces on one side of each tray may be left blank while the two spaces on the ppposite side of the tray are occupied by downspouts 42.

The top rim of each downspout should be not higher than the level of the top rims of the short lengths of pipe 20 under the bubble caps; but the bottom rim of the downspout should be fairly close to the tray below. Water will then fill each tray level with the upper rims of the downspouts and overflow into them. To prevent the water from remaining stagnant in any part of a tray the pairs of downspouts on successive trays should be located alternately on the right and left sides of the tray. (see Figure V).

Number one carbon steel plate maybe used in the construction of the condenser. Where joints are bolted rather than welded for greater ease of uncoupling and tightness of the joint is important, asbestos gaskets may be used.

In the preferred method of operating the condenser, the coldest water available for the purpose is introduced thru the water inlet pipe 31 until the water level rises as high as the valve 35 so that water begins to flow out thru the water outlet pipe 32. The flow of water thru water inlet pipe 31 is then reduced to a rather slow rate and valves 35 and 37 are regulated until a small but steady trickle of water flows out thru the hydrocarbon outlet pipe 40. When this stage is reached, the hot vapor to be condensed, which may be mixed with fixed gases, can be turned into the condenser thru the vapor pipe 27.

As condensed hydrocarbons begin to come out thru the hydrocarbon outlet pipe 40 the regulation of valves 35 and 37 is continued to keep a slight amount of. water flowing out along with the hydrocarbons, while the rate of flow thru the water inlet pipe 31 is gradually-increased until the temperature of the hydrocarbons leaving the condenser is substantially equal to the temperature of the water entering.

If the condenser is provided with additional trays as in Figure V cold water can then be turned on to these trays thru the auxiliary water inlet pipe 41. The flow of water thru the auxiliary water inlet pipe 41 should be gradually increased until the temperature of the gas leaving thru the gas pipe 26 is as close as possible to the temperature of the water entering thru the auxiliary water pipe 41. At the same time the valves 35 and 37 should be kept adjusted so that the quantity of water leaving thru the hydrocarbon outlet pipe 40 is substantially equal to the quantity of water entering thru the auxiliary water pipe 41. The mixture of hydrocarbons and water goes from the hydrocarbon outlet pipe 40 to a settling tank 43 shown diagrammatically in Figures 11 and VI in which the hydrocarbons are separated by gravity so that they can be piped to storage.

If it is desired to dispense with a separate settling tank the condenser may be kept filled with water not higher than the top rims of the vertical lengths of pipe 20 on the tray 18 that is immediately below the hydrocarbon outlet pipe 40. The layer of hydrocarbons will then separate out on top of the water so that the water-free hydrocarbons can be drawn ofi thru the hydrocarbon outlet pipe 40. The depth of the layer of hydrocarbons or the level to which the condenser is filled with water can be maintained constant by regulation of the valves 35 and 37, thru which all the water passes.

As the water entering thecondenser in Figure V thru the auxiliary water inlet pipe 41 is considerably colder than the main supply of cooling water, the upper two of the three inlets for the 'main supply of cooling water thru the water inlet pipe 31 may be closed off so that all the water passes thru thelower of the three inlets. Two trays are then kept filled with the colder down flowing water from the upper series of trays. Since the bubble caps 21 break up the water currents and prevent the formation 01' isolated descending streams of cold water that might otherwise be present, the two trays remain filled with the colder water from above; and it gradually overflows thru the short lengths or pipe on the lower of the two trays and mingles with the main body oi cooling water that is entering the next tray below.

Since the quantity of colder water passing the upper series of trays is relatively small it may be practicable to lower the temperature of this water as far as 40 F. by artificial cooling. Since the water that goes out with the hydrocarbons from a condenser constructed according to Figure V is substantially all water from the trays above at a temperature that may be not far above 40 F., the hydrocarbons will be chilled and after separation from the cold water. if necessary, in a settling tank will tend to evaporate less readily during storage. Even when the condenser is constructed as in Figure I, the cooling water can be brought below the temperature of the air by simple aeration, so that the hydrocarhens in being cooled substantially to the temperature of the cooling water are chilled below the temperature of the air.

Any structure that is substituted for the bubble cap trays should be similarly well adapted to break up the vertical flow of liquids into many small currents, because the presence of hot liquids at the bottom and cold liquids in the top of the condenser would otherwise cause undesirable return currents. The temperatures throughout the condenser should vary gradually and uniformly from one end to the other.

Placing the vapor and water inlets on the opposite side of the condenser from the water and hydrocarbon outlets makes it impossble for the hydrocarbons to flow thru the condenser,

without crossing the path of the flow of cooling water. Furthermore, because of the wide sep aration of the water inlet from the hydrocarbon outlet and of the vapor inlet from the water outlet there is less danger that any of the hydrocarbons will get over to the water outlet or that any of the cooling water will get over to the hydrocarbon outlet when it is desired to take out only the colder water from. the higher trays with the hydrocarbons.

Water from the pool on top of one of the added trays in Figure V can flow downward thru the down spout 42 to the tray below; but only gas can rise upward to the tray above. Thus it is made impossible forthe gas and cooling water to flow otherwise than in true counter current during the last and most important stage of cooling of the gas. When this colder water is being taken out with the hydrocarbons, it flows from the last down spout 42 directly to the hydrocarbon outlet pipe 40 shown closely adjacent the last downspout, in Figure V, before it can mix with any of the less cold water.

The portion of the condenser adjacent the water outlet that is enclosed by the screen 39 forms a well in which any hydrocarbons that may possibly have entered will flow directly to the top without mingling with the water going to the outlet; yet the screen 39 forming one side of the well allows hot water to flow directly across to the water outlet pipe 32 which may lead it to a heat interchanger or other device for utilizing the heat, from which the water may flow, if necessary, to a closedtank so that it may stand until any hydrocarbons present have separated out.

The hydrocarbons leaving the condenser will be either crude or finished depending upon the character of the vapors introduced. Treating chemicals may be added to the cooling water for refining purposes if desirable. The height of the condenser and the number of trays may be increased or reduced as a more eflicient or less eflicient utilization of the cooling water is necessary.-

Since the gas leaving the top of the condenser thru the gas pipe 36 contains a small amount of hydrocarbon vapor it will be worthwhile to put it thru one of the well known stripiping processes such as the compression, absorption or charcoal process, provided that there is a sufficient quantity of the gas going out to give a sufficient recovery of hydrocarbons.

The condenser can be used for the gasoline vapors coming from a plant for topping or skimming crude petroleum, whom a cracking plant. In a plant for stripping gasoline from casing head gas by the compression, absorption or charcoal process one of these condensers may be used to cool the gas after each compression thereof, and after the gas passes thru a vacuum pump, it one is used to withdraw the gas from. the well. Some gasoline will be separated out in such use of the condenser when the casing head gas is rich enough. Also after the gasoline has been distilled off from the charcoal in densate flowlng toward the bottom the home a charcoal plant or from the absorption oil in an absorption plant, as by steam distillation, it

can be condensed in a device constructed in accordance with the invention.

Should the flow of cooling water be interrupted there will be no danger that the hot vapor entering the condenser will come in contact with air so as to be ignited before substantiallyall the water contained in the corn denser has been boiled away. There would be time meanwhile for the plant producing the hot hydrocarbon vapors to be shut down. As a final precaution the vent pipe 33 may be extended so that the open end 34: may be located at some distance from the plant where the hot vapors can escape and. burn without causing any danger. 4

Although the condenser has been described {as intended for the condensation of hydrocarbon vapors by means of cooling water, it is obvious that itmay be used for the cooling of gas that is sparingly soluble in the cooling liquid, or used for the condensation of any vapors whether mixed with fixed gases or notproviding a cooling liquid is used that forms substantially no solution with the condensed vapors. The cooling liquid should preferably have a specific gravity that is substantially difierent from that of the condensed vapors.

If the specific gravity of the condensed vapors is greater than that of the cooling liquid used the vapors can be introduced thru the pipe 31 and the cooling liquid thru the pipe 2'! so that the condensed vapors flow to the bottom of the condenser and form a layer from which they maybe withdrawn thru the pipe 32 while the cooling liquid rises to the top and flows out thru the pipe 40. With the hot vapor entering at the top'of the condenser and the cooled conplate system in the condenser canbe more sim- .ple, undesirable return currents being then out or the question.

The embodiment of my invention herein shown and described is to be regarded as illustrative only, and it is to be understood that the invention is susceptible of variation, modification and change within the spirit and scope of the subjoined claims. 3

I claim as my invention: I

I 1. Apparatus for condensing vapors, includin a condensation chamber, a column of liquid in the chamber that forms substantially no solution with the condensate to be produced, at a temperature below the boiling point of the condensate, means for introducing the vapors into said column, so that the condensate forms and tends to separate" out into a layer at one end of said column, means for withdrawing the condensate at the end of said column at which it tends to separate out, and means for inducing a flow of cooling liquid across the path of flow of the vapors and the condensate through the column from the point at which the vapors are introduced to the point at which the condensate is withdrawn.

2. A process of condensing vapor containing fixed gas that includes maintaining a column of cooling liquid that forms substantially no solu-' tact cooling of the vapors to be condensed, at a temperature below the boiling point of the condensate to be produced, means for injecting the vapors into said column, means for withdrawing condensate at the end of said column where it tends to separate out, means for passing fresh cooling liquid through the column in countercurrent to the condensate, and means for breaking up eddies and undesired currents in the column.

4. A condenser including a condensation chamber containing a column of a cooling liquidsuitable for direct contact condensation of the vapors to be treated, means for introducing the vapors into said column, means for removing condensate from the end of said column where it tends to separate, means for passing fresh cooling liquid into and through the column, means in the column {or breaking up eddies and undesired currents, and means for substantially barring vapor and condensate from passing out with the used cooling liquid from the column.

5. A condenser including a condensing chamber holding a column of liquid suitable for direct contact cooling of the vapors to be condensed, at

a temperature below the boiling point of the condensate, means for maintaining the condensing chamber filled to a desired level, means for introducing the vapors into the column of liquid, means for removing condensate from the end of the column of liquid at which it tends to separate out, means for passing fresh cooling liquid through the column in counter-current to the condensate, and means in the column for breaking up undesired currents.

6. In a 'direct-contact condenser, a condensation chamber, means for maintaining in the condensation chamber a column of suitable cooling liquid of .a desired height, means for injecting vapor into .the column, means for removing condensate from the column at one end, means for passing cooling liquid into and through the column, means in the column for breaking up undesired currents, and means for substantially barring vapor and condensate from passing out with the overflow cooling liquid from the column.

7. In a condenser, a-condensation chamber containing a column of suitable'liquid, means for injecting the vapor into the column, means for removing condensate from the end of the column where it tends to separate, separate means for introducing and withdrawing cooling liquid, and partitioning means for substantially obstructing vapor and condensate from passing out with the used cooling liquid.

8. Apparatus for condensing vapor including a condensation chamber containing a column of a suitable liquid, means for injecting the vapor into the column, means for adding fresh cooling liquid, means for withdrawing condensate mixed with cooling liquid from the end of the column where the condensate tends to concentrate, and means for separating condensate from the withdrawn mixture.

9. In an apparatus of the class described, a

"chamber holding a column of cooling liquid,

means for injecting vapor into the column, means forintroducing and withdrawing cooling liquid, partitioning means for substantially preventing vapor and condensate from passing out with the cooling liquid, means for withdrawing'a mixture of condensate and cooling liquid at the end of the column where the condensate concentrates, and means for separating the condensate from said mixture.

10. A condensation process that includes maintaining a column of cooling liquid, injecting vapor into the column, adding fresh cooling liquid at a rate just suflicient to condense all the vapor and maintain the low temperature of the column, withdrawing condensate from one end of the column together with some cooling liquid, and separating the condensate from the withdrawn mixture.

11. A condenser for vapor containing fixed gases including a condensation chamber holding. a column of suitable cooling liquid, means for injecting the vapor into the column, means for removing condensate at the end of the column where it tends to separate, and means in the portion of the chamber above the column for washing the residual fixed gases with fresh cooling liquid and thereafter leading the fresh cooling liquid into the column.

12. Condensation apparatus that includes a condensing chamber containing a column of suitable liquid, a source of liquid connected to pass fresh cooling liquid into the column, means for introducing the vapor into the column, means for removing condensate from the end of the column where it separates, means for maintaining substantially constant the depth of the separated layer of condensate, and means for substantially barring vapor and condensate from passing out with the overflow cooling liquid from the column.

13. Apparatus for condensing vapor comprising a condensation chamber containing a column of suitable liquid, a source of liquid connected to pass fresh cooling liquid into the column, means for introducing the vapor into the column substantially below the surface thereof, and means for removing condensate at such a rate that a layer of condensate of desired depth is maintained at one end of the column.

.14. In a condensing apparatus a condensation chamber holding a column of suitable cooling liquid, means for injecting vapor into the column substantially below the surface thereof, means for removing condensate from the column at the end where it separates, a source of liquid connected to pass fresh cooling liquid across the path of the condensate through the column, and means to produce mixing of the currents of condensate and cooling liquid and to lead the condensate into a layer at the end of the column.

15. A condensing apparatus comprising a condensation chamber containing a column of suitable liquid, means for injecting vapor into the column, means for removing condensate from the end of the column where it separates, a source of liquid connected to pass fresh cooling liquid into the column, means to guide the currents of condensate and cooling liquid through the column in intimate contact, and means for maintaining a layer of condensate of substantially constant depth at the end of the column.

LOUIS T. CAMERON.

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