US1572374A - Heat-exchange device - Google Patents

Description

Feb. 9 1926. 1,572,374

H. L. ALLAN HEAT EXCHANGE DEVICE Filed Dec. 15, 1919 2 hee l .Fi/yl. h

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H. L. ALLAN Filed Dec. 15, 1919 HEAT EXCHANGE DEVI CE 2 Sheets-Sheet 2 Patented Feb. 9, 1926.

UNITED STATES fiUGH LOGIE ALLAN, or AYR, SCOTLAND.

H AT EXCHANGE nnvxcn.

Application filed December 15, 1919., Serial No. 344,791.

vTo all whom it may concern:

dom of Great Britain and Ireland, and resident of 46 Park Circus,'Ayr, Scotland, and of the- Btu-mall Oil Company Limited, Rangoon (Post Box No. 67), Burmah, British India, have invented a certain new and useful Heat-Exchange Device, of which the following is a specification.

This invention relates to an improved heat exchange device for the continuous distillation and continuous fractionation of petroleum or other hydrocarbons or mixture of volatile liquids, and has for its object to improve the apparatus described. in the specification of United States Patent No. 1,390,742 with a View to obtaining a larger production of light and heavy benzine of given density than that obtained by'existing dephlegmation methods, and also to obtain the maximum yieldof white products continuously and in one operation.

According to the present invention the ap paratus comprises a series of vessels for evaporating, distilling and fractionating hydrocarbons or the hke, the vessels being I each divided into three superposed compart ments, the oil being fed to the lowermost compartment and passing from thence into the uppermost compartment through tubes in .the intermediate compartment. Preferably the uppermost compartmentis provided with tubes in staggered relation to the tubes in the intermediate compartment and extending therefrom for a distance upwardly, so that the oil ascends the tubes and de scends outside the tubes in the uppermost compartment, flowing down the outer Walls of the tubes in the form of a film, before passing through a cascade pipe intothe lower compartment of the adjacent vessel.

During its passage through the vessels the oil is heated by vapours which pass through the intermediate compartments of the vessels. The lighter ortions of the oil are thus evaporated o "and pass into a fractionating apparatus.

.The fractionating apparatus preferably comprises two rows of atmospheric fraction atmg condensers connected in cascade formation, the atmospheric condensers being substantially of similar construction to the aforesaid vessels.

For the sake of convenience the invention will be hereinafter described with reference to the accompanying drawingswhereonz- Fig. 1 is a diagrammatic front View of the atmospheric condensers or fractionating apparatus.

Fig. 2 is a fragmentary detail view of two adjacent atmospheric condensers.

Fig. 3 is a vertical sectional view of the lower portion of one of the atmospheric condensers. I

As shown on F igs.- 1 and 2 of the accompanying drawings, the apparatus comprises a plurality of atmospheric condensers A to A". I

As shown in Fig. 3 the atmospheric condensers are divided by partitions into three compartments 70, Z and mby means of a lower partition or tube plate 7) and an upper partition composed of two tube plates 41. and 0, the tube plates supporting two series of tubes 1', s. The atmospheric condensers are connected in cascade formation by means of cascade pipes 16 connecting the compartment 7: of one vessel to the compartment m ofthe adjacent vessel.

4 The li hter portions of crude oil evaporated off in a preheater pass through the pipes 27 (Fig. 1) to the atmospheric condenser A Y The condensates in the atmospheric condensers cascade or flow backwardly from one condenser to the next, and are thusre-evaps orate'd by the higher temperature of the condensates in the atmospheric condensers to which they return.

The units of the fractionating apparatus may be heated by steam or hot oil, the steam or hot oil being admitted to the intermediate compartment Z of the units so as to pass around the tubes 8 therein (Fig. 3). If hot oil is used, it would be admitted by the connection 25 at the lower end of the compart-' ment 1 and be discharged'from the outlet 13 near the upper end thereof. The lowermost compartment m may also be heated by steam through steam pipe 26. Preferably, two tube plates 01. and 0' spaced slightly apart are employed to separate the intermediate vcompartment Z from the uppermost com-' ment is by the upper plate n. Owing to the oil overflowing the upper tubes 1' and flowing down the outer walls thereof, maximum re-evaporationis facilitated, thus giving in- .creased efliciency.

If desired, the pipes of the atmospheric condensing apparatus may be cooled by either air or water, but as water cooling has objections such as liability to corrosion and excessive cooling, additional air-cooled surface for the pipes may be provided by fitting them with internal air conduits, supplied with either natural or forced draught and fitted with control valves for controlling the cooling effect. I

The atmospheric condensers are connected by the condenser pipes 27 indicated diagrammatically in Fig. 1. Preferably the pipes 27 are connected to headers 29 (Fig. 2% one header 29 connecting the rising pipes 2 of one condenser with the falling pipes 27 of the adjacent condenser. The cascade pipes 16 may be provided with overflow pipes 30 (Fig. 3) and valves 31 indicated diagrammatically in 2.

As will be seen, with particular reference to Fig. 3, the oil enters at 16 and rises' through tubes .5- and 4,flowing down the outer surfaces ofthe latter and escaping by the outlet pipe 16 which forms the inlet for the next lower condenser of the series.

30 The vapours escape at the top of (the conof the pipe arrangement diagrammatically shown in Fig. 1 and more specifically in Figpartment to the space between the tube plates, a second series of tubes extending partially into the uppermost compartment from the said space, a liquid outlet .near the bottom of said uppermost compartment, :1.

vapour outlet in the 'top of the uppermost compartment and means for circulating a heating-medium around the first-mentioned series of tubes.

2. A heat 'exchange device as specified in claim 1v having an external overflow pipe connecting the upper part of the uppermost compartment with the liquid outlet in the bottom thereof.

3. A heat exchange device as specified in claim 1 having condenser pi es extending upwardly from the vapour out et.

nUcn LOGIE ALLAN.

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