US1278279A

US1278279A - Fractional condensing heat-exchanger.

Info

Publication number: US1278279A
Application number: US17524617A
Authority: US
Inventors: Edward H Wright; Edwin H Atwood
Original assignee: Vacuum Oil Co
Current assignee: Vacuum Oil Co
Priority date: 1917-06-18
Filing date: 1917-06-18
Publication date: 1918-09-10
Anticipated expiration: 1935-09-10

Description

E. H. WRIGHT & E. H. ATWOOD.

FRACTIONAL CONDENSING HEAT EXCHANGER.

3 SHEETSSHEET I.

E. H. WRIGHT & E. H. ATWOOD.

FRACTIONALCONDENSING HEATEXCHANGER APPLICATION FILED JUNE 18, 1917' Patented Sept. 10, 1918.

3 SHEETSSHEET 2.

E. H. WRIGHT 61 E. H. ATWOOD.

FRACTION/II. CONDENSING HEAT EXCHANGER. APPLICATION FILED JUNE I8 IQI]. 1,27%,279. PatentedSept. 10,1918.

3 SHEETSSHEET 3.

Fig.2..

' Fig.3.

' United States,

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a rare raana ra ion.

EDWARD H. WRIGHT AND EDWIN H. ATWOOD, OF OLEAN, NEW YORK, ASSIGN'ORS TO VACUUM OIL COMPANY, OF ROCHESTER, NEW YORK, A CORPORATION OF NEW YORK.

FRACTIONAL CONDENSING HEAT-EXCHANGER.

Specification of Letters Patent. Patgnted Sept. 10, 1918.

Application filed June 18, 1917. Serial No. 175,246.

To all whom it may concern:

Be it known that we, EDWARD H. WRIGHT and EDWIN H. A'rwooo, citizens of the and residents of Olean, in the county ofCattaraugus and State of New York, have invented certain new and useful Improvements in Fractional Condensing Heat-Exchangers, of which the following is a specification.

This invention relates to a combined fractional condenser and still whereby heat is transferred from the vapors that are to be condensed to oil that is to be distilled, and has for its object economy of heat, and efficiency in fractional condensation. It is specially useful in connection with apparatus adapted for continuous distillation of petroleumhydrocarbons, though not restricted thereto.

In the drawings Figure 1 is a longitudinal vertical section through a portion of the apparatus;

Fig. 1 is a continuation of Fig. 1 being partly in exterior elevation;

Fig. 2 is a vertical section on the line 2-2 of Fig. 1*, also partially shown in elevation; Fig. 3 is an end elevation viewed from the right-hand end of Fig.1; and

Fig. 4 is a fragmentary enlargement of the sectional portion of Fig. 2.

The parts of the appliance are inclosed within a single sheet-metal casing or shell 1,

which reduces to a minimum radiation losses and cost of construction. Furthermore, as will appear, this construction makes it possible to provide for the removal of the various parts of I he appliance for examination,

cleaning or repairing.

The vapor from the still (not shown) enters the appliance at the lower end of the casing (see Fig. 1") through a pipe 2. The condensate passes off from. the appliance through pi es 3 (see Fig. 3) The vapor remaining uncondensed after-passing through the appliance leaves the casing at its upper :end through the pipe 4 by which it is conducted to another condenser (not shown), where condensation is completed. The crude oil to which the heated vapors are to transfer their heat enters the casing at its upper corner through a pipe 5. andis discharged therefrom into the'still (not shown) through the pipe 6.

hus, it will be seen that the vapor from siderable velocity, into a which it flows back in the opposite direction on one side of the casing the still and the oil for charging the still flow through the appliance in opposite directions, so that the oil is gradually heated as it flows down through the appliance, and the vapor is caused to undergo fractional condensation. The oil becomes hotter as it passes down through the appliance, whereas the vapor becomes cooler as it. passes up therethrough.

The-appliance is constructed of a plural ity of similar sections arranged one above the other, through which oil and vapor flow successively. From the pipe 5 oil enters an upper chamber '7 of the header 8 whence it flows through a set of small tubes 9, at conchamber 10, from through a lower set of small tubes 11 into a chamber 12 also located in the header 8. A pipe 13 conveys the oil from the chamber 12 to the upper chamber 14 in the header 15 of another section similar to that described.-

In this second section the oil flows from the chamber 14 through pipes 16 into a chamber 17, from which it flows back through pipes 18 into a chamber 19, as in the section first described. From this point on the oil flows back and forth through the upper and lower sets of small tubes of other sections that are the same in construction as those described, eventually passing into the still through the pipe 6 previously mentioned.

Each section also has an open pan 20 which collects the condensate of the vapor as it drips from the sets of oil-carrying tubes. A number of transverse baffles 21 extend from the bottom to the top of each pan. The bafiies have perforations 22 (see Fig. 4) at their lower edges, adjacent the bottom of the pan, so that the distillate when condensed and directed into one end of the pan (the left as shown in the drawings) will be retarded as it flows toward the outlet at the other end of the pan through which itis discharged. 5

A partition 23 separates the upper and lower sets of oil-carrying tubes. and is connected with the head 8 on the left but terminates at 24, short of the opposite head 10. A similar partition separates the upper and lower sets of oil-carrying tubes in the other sections. The condensate from the upper set of oil-carrying tubes falls on the partition 23, and flows over its end 24 onto the top 25 of the pan 20. From the top 25 the -Which directs it into the end 20. of the B5 of the pan so as to be pan 20.

This end 20 of the pan 2O terminates short of the side of the appliance so that the vapor as it rises through the appliance can pass around this end of the pan. At the other end of the pan 20 is located a trap 27 which prevents the condensate from being drawn oil from the pan with such rapidity as to permit vapor to pass into the draw-off lines and cooler. The pan 20 is supported by rails 28 (see Fig. 4) which rest on rails 29 attached to the casing 1. The pans are alike in construction and are similarly arranged Within the casing.

It should be noted that the pan is at a higher temperature than the condensate on the oil-carrying tubes above the pan, and, accordingly, that fractions lighter than those that condense at the temperature of the pan revaporate if they happen to collect in the pan. Also that the end of the pan from which the condensate is discharged through the trap to the condensate running line 3 is the hottest part of the pan, because the vapor comes in contact with this end of the pan before it gives up heat to the pan, which serves efi'ectively to keep out of the running line 3 fractions lighter than those that it is desired to collect in the pan. And, finally, that the retardation of the flow of the distillate through the pan by the bafiies prevents circulation within the pan and subjects the condensate to the heat of the vapor for an appreciable interval, which also assists in eliminating fractions of lighter gravity and lower flash point than the bulk of the condensate collected in the The light fractions driven off from the pan and reevaporated from the pan pass out of the pan and up through the appllance .to cooler sections where they are caused to condense and pass off with fractions of the same gravity. The top 25 of each pan is suflicient-ly hot to prevent any of these reevaporated fractions from recondensing before they leave the pan and fall back into the pan.

Still other means are provided for reevaporat-ing from the pan the light fractions which it is desired to eliminate and carry from the condensate. namely. steam, or other heating or carrying medium, or both heating and carrying mediums, discharged into the pan, preferably in the form of spray. In the drawings each pan is represented as provided with two longitudinal steam spray-

pipes

31, 31. In connection with these spray-

pipes

31, 31 are shown superheaters 32. 32 (see Fig. 4 and the lowest section in Fig. 1*), each comprising coils located between the casin and the sides 30 Eeated by the hot vapors about the pan. The

superheaters

32, 32 receive steam through

pipes

33, 33 from steam supply pipes 34:, 34, and are connected with the spray-

pipes

31, 31 through.

the pipes 35, 35 (see Fig. 1). The vapor superheats the steam, and the steam is blown through the condensate in the pan, heating it and agitating it, so that lighter fractions tltifan those that belong in the pan are driven o In operation the hot vapor from the still is delivered by the pipe 2 beneath the discharge end of the lowermost pan (at the right'in Fig. 1"), whence it passes along the bottom of the pan to its other end, and up around the end of the pan, heating the pan in its course; thence back on its course over the set of oil-carrying tubes located between the top 25 of the pan and the partition 23; thence up around the end of the partition 23 (at the right in the drawings) and, again reversing its course, over the set of oil-carrying tubes located above the partition 23. And so the vapor passes in the same manner up through all the sections around the sides of the pans, and in zigzag course along the bottom of each pan around one end, back in the opposite direction over the set of oil-carrying tubes immediately above the pan, around the end of the partition and back again over the upper set of tubes. Transverse baflles 36 extend up into the course of the vapor from the top 25 of each pan, and similar baffles 37 project down into the course of the vapor from each partition, alternately. A similar arrangement of

baflles

38 and 39 is provided above the partition 23. All of these

battles

36, 37, 3S and 39 are attached to the partition 23 as indicated in Figs. 1 and 1". These bafiies retard the flow and break up current in the vapor and diffuse it throughout these spaces that contain the oil-carrying tubes so that all of the hot vapor is brought into contact rcpeatedly with these tubes. Similarly the aflies 21 within the pans retard the fiow and break up currents in the condensate. The condensate accumulates within the pans, flowing through them from their ends 20 to their other ends, and in so doing passing through the openings 22 at the lower edges of the bafiies 21, till the oil has risen within the pans in each case to the level of the opening 27 leading into the trap 27, whereas has also been'described.

A safety valve 40 controlling a relief bypass ll is provided, the by-pass leading to the vapor line 4.

The oil-carrying tubes of each section may be withdrawn from the side of the casing as a unit for examination, cleaning or repair, by disconnecting the pipes 5 and 13 and removing the head 8 or the head 14, as the case may be. p

The pans can also be removed from the other side of the casing by disconnecting the steam pipes 3 1, the pipes 3 for withdrawing the condensate (see Fig; 3), and the manhole head 42.

hen continuously operating stills are run in series the fractions obtained are apt to vary in range because of difficulties experienced in regulating the flow to each still proportionately to the vaporization taking place therein and with reference to fluctuations in temperature and pressure. Furthermore, it is ditlic-ult, if not impossible, to obtain as the result of distillation by continuously operating stills a fractionation carried to the degree sometimes required. By the use Of this appliance in conjunction with continuously operating stills, irregularities in fractionation are corrected and the distillate may be further divided.

The process herein described forms the subject matter of an application filed by us on December 19, 1917, Serial No. 207,925.

We claim:

1. A 'combined oil preheating and vapor condensing appliance comprising a plurality of sections arranged one above the other, each section consisting of a plurality of separated oil-carrying pipes and a condensate collecting pan below them so arranged with reference to each other and so connected with the oil-carrying pipes and collecting pans. respectively, of adjacent sections that the oil flows downwardly in zigzag course through one. section after another and the.

vaporfiows 1n zigzag course in the opposite direction below and then above each set of pipes and each pan.

2. A combined oil preheating and vapor condensing appliance comprising a plurality or sections arranged one above the other. each section consistin of (1) two sets of separated oil-carrying pipes divided by a partition extending from one side of the casing and of the casing, and (2) a collecting pan beneath said oil-carrying pipes extending from the other side of the casing in the opposite direction and terminating short of the side of the casing, so that the vapor flows up through the appliance above and below each set of pipes and each pan in zigzag course.

3. A combined oil preheating and vapor condensing appliance comprising a plurality of sections arranged one above the other, each section consisting of a condenser. and a condensate collectingpan beneath the condenser. the latter being adapted to receive the condensate at one end, having bafiie partitions to retard the flow of the condensate therethrough, and a trap located at the other end whereby a predetermined level is maintained within the pan. 4. A combined oil preheating and vapor condensing appliance comprising a plurality of sections arranged one above the other, each section consisting of a' condenser, a condensate collecting pan beneath the condenser. and a steam spray pipe within the collecting pan.

A combined oil preheating and vapor condensing appliance comprising a plurality of sections arranged one above the other, each section consisting of a condenser, a condensate collecting pan beneath the condenser, a steam preheater heated by the vapor, and a steam spray pipe within the pan.

6; A combined oil preheating and vapor condensing appliance comprising a casing, a plurality of sections arranged one above the other, each section consisting of (1) a' plurality of separated oil-carrying pipes extending from one side of the casing, terminating short of the other side of the casing. and removable as a unit from the side of the casing. and (2) a collecting pan beneath said oil-carrying pipes extending from the opposite side of the casing and terminating short of the side of the casing, and removable from the side of the casing.

EDlVARD H. WRIGHT. EDlVIN H. ATWOOD.

terminating short of the other side