US1701166A - Hot-oil pump - Google Patents

Description

F eb. 5, 1929.

T. DE C. TIFFT HOT OIL PUMP Filed June 7, 1927 ATTORNEYS Patented Feb. 5, 1929.

UNITED STATES PATENT OFFICE.

THOMAS DE COLON TIFFT, OF CHICAGO, ILLINOIS, ASSIGNOR TO SINCLAIR REFINING COMIANY, OF NEW YORK, N. Y., .A CORPORATION OF MAINE.

HOT-OIL PUMP.

This invention relates to improvements in pumps intended for handling hydrocarbon oils at or near a cracking temperature and under high pressure. Inv such service, pumps are subjected to peculiarly severe operating conditions yet must be dependable in operation and safe in operation. This invention provides an improved pump which meets the requirements ot'l such operatingr conditions, which is dependable and safe in operation, and which nevertheless is relatively inexpensive in construction. The improved pump of the invention is of positive displacement type and the construction is suchthat single units of large capacity can b`e built.

IIn the improved pump of the present invention. the working parts of the pump are" `trated in the accompanying drawings, and

the invention will be described in connection therewith. In the drawings; Fig. 1 represents a vertical section through the improved pump of the invention. Fig.,2 is a section on line 3 3 of Fig. 1. Fig. 3 is a fragmentary section on line 4 4 of Fig..1, and Fig. 4 is a section on line 5 5 of Fig. 2. y

Referring to Figs. 1 to 4 of the accompanying drawings. the working parts of the pump comprise apair of driven members 6 and 7 arranged within a working chamber 8. Each end of each driven member is in the form of a helical screw thread adapted to intermesh with and closely lit the screw thread on the adjacent end of the other driven member. the screw threads on opposite ends of each driven member being arranged in opposite helixes. The working chamber 8 closely tits the peripher)7 of the screw threads on the driven members 6 and 7 outside of the zone in which the screw threads intermesh. and in that zone the intermeshing screw threads form a complete closure betwefl.1 the axes of the driven members, (see Fig. 3). In operation, the driven members are rotated in opposite directions (see arrows in Fig. 3) and this rotation forces oil from the open ends of the working chamber 8 to the central space therein between the intermeshing pairs of screw 1927. Serial No. 197,210.

threads in a succession of pockets formed between the screw threads on eachv of the driven members 6 and 7, the walls of the working chamber 8 and the intermeshing screw thread on the other driven member. Oil is thus drawn from the interior of the housing through suppty connection 9 and forced out through discharge connection 10.

The housing in which the work'ng parts of `the pump are arranged comprises 'a central member 11 and end covers 12 and 13. The working parts of the pump, the working chamber 8 and the actuating elements 6 and 7, are arranged entirely within this housing and an operating extension for the actuating. elements is carried out through the housing.

The working parts of the pump form no part ofthe housing. The construction is suchthat bearings. stuiiing boxes, etc.. are atl'orded a maximum of protection against hotoil circulating through the pum to which the working parts of the pump are exposed.

Each of the driven members 6 and 7 is mounted upon a shaft, 14 and 15 respectively. carried` in bearings beyond the ends of the driven member. These bearings are located outside of the working chamber of the pump and are supported independently of the working chamber of the pump. VEach of the shafts is carried in two inner bearings 16, all of which are alike. These inner bearings are supported bv plates 17 and 18 bolted between the face of the central housing member 11 and the end covers 12 and 13.` The inner bearings 16 are bushings mounted in collars 19 which are secured in the plate's 17 and 18. l

Outer bearings 20 are also provided on shaft 15. These outer bearings are bushings mounted in 'sockets 21 which are secured in the end covers 12 and 13. The outer ends of the sockets 21 are open and are fitted with covers \12 and 13. Either or both of these operating extensions is connected to some suitable drlvmg means, such as an electric motor or 4a. steam engine. The maintenancek of a hydraulic balance within the pump is promoted by carrying both ends of the driving shaft through stuffing boxes, as illustrated, but this shaft may be driven from one end only,

Shaft 14 is driven from shaft 15 by gears 27 and 28 arranged within the end cover 12. These gears are arranged to maint-ain the two driven members 6 and 7 in fixed relation and to effect rotation vof the two driven members in opposite directions at equal speeds. A pair of gears similar to gears 27 and 28 may be provided at the other ends of the shaft-s 11 and 15. The several inner bearings 16 are arranged to lit the shafts 111v and 15 relatively loosely and the outerbearings and 23 to fit the shafts more closely. The plates 17 and 18 form compartments 29 and 30 within the end covers 12 and 13 respectively which by these plates are separated from the interior of the central housing member 11 through which hot oil passes.A Connections 31 and 32 are provided for supplying to the compartments 29 and 30 respectively oil under pressure somewhat greater than that prevailing on the other side of the plates 17 and 18. Apertures 33 are provided in the closed socket 24 to establish communication between the space between the closed end of the socket and the end of the shaft 14 and the compartment 29.

1n operation the shaft 15 is rotated (counter-clockwise facing Fig. 3) forcing oil from the space within the central housing member 11 into the central space within the working chamber 8 and out through connection 10, and cool oil is supplied through connections 31 and 32 under pressure somewhat exceeding that prevailing within the central housing member 11 to establish a ow of oil inwardly through the inner relatively loosely fitting bearings 16 into the chamber within the central housing member 11 and the plates 17 and 18. This inward flow of cool oil assists in cooling and lubricatin these bearings and in preventing escape of ot oil through the bearings, and also makes it possible to have theinner bearings 16 of loose enough fit to avoid sticking or binding over the Wide range of temperatures to which such pumps are commonly subjected, say from ordinary atmospheric temperature up to 800o F. or more, without interference with satisfactory operation. 'lhe apertures 33 assist in lubricating the outer bearin 23. Y The construction just described makes i possible to use cast iron from the driven members 6 and 7 and for the working chamber 8 off the pump, a particularly advantageous and economical material for these working parts of the pump, without any prejudice to safety, as the elements of the external housing may be made ofsteel forgings. Steel shafts may be used and the plates 17 and 18 may be of -sheet steel. This con- A struction makes it possible to use forgings Moines where required for safety and involves but a minimum of machine work on such forgings. The driven members 6 and 7 and the working chamber 8 are readily machined from castiron. The various iittings attached .to the housingelements may also with advantage be of forged steel. lt will be noted that 1n the construction shown the passage withinY and 18. 1n operation, the outer more closely fitting bearings are exposed only to the relatively low temperature of cool oil supplied to the compartments 29 and 30 while the inner .bearings 16 exposed to the higher temperature of hot oil circulating through the pump iit relatively loosely and are'further protected by cool oil forced through the bearings into the interior of the pump from the compartments 29 and 30,

The improved pump of the invention is of special value and application in connection `With pressure stills for cracking hydrocarbon oils of the general type described and illustrated in Letters Patent No. 1,285,200 granted to the Sinclair Refining Company, November 19, 1918, on an application of Edward W. lsom, and has further special advantages in connection with the modified pressure still of this generaltype illustrated in application Serial No. 197 ,035, filed J une 7, 1927. This modified pressure still, and the oil heater embodied in it, are the invention, in so far as they are novel, of Harry L. Pelzer, ya resident of Highland, in the county of Lake and State of Indiana. l

While the invention has been described' in detail in connection with one particular pump illustrated in the drawings, and its special utility in connection with one type of pressure still system particularly emphasized, it

will be understood that this detailed and specific description and showing of the 1nvention is intended to illustrate and exemplify the invention and that the improved pump of the invention may be embodied in other 'forms and used to special advantage in connection with other cracking systems.

1 claim: r Q

1. An improved hot oil pump comprlslng a housing made up of a centralhousing member, end covers therefor and plates arranged between the end covers and the central hous.

ing members forming compartments Within the end covers separated by the plates from the space within the central housing member, a working chamber independent of `-ne housing and arranged within the central housing member, a shaft extending through the working chamber and into the compartments in the Cil end covers through bearings supported by the plates arranged between the end covers and the central housing member, and means arranged Within the working chamber and on said shaft adapted to t'orce oil through the working chamber. f

2. An improved hot oil pump comprising a housing made up of a central housing member, end covers therefor and plates arranged between the end covers and the central hous-V ing member forming compartments within the end covers separated by the plates from the space within the central housing member, a working chamber indcpendent of the housing and arranged within the central housing member, a shaft extending through the Working chamber and into the compartments in the end covers through bearings supported by the plates arranged between the end covers and the central housing member, and means arranged within the Working chamber and on said shaft adapted' to force oil through the working chamber, said cent-ral housing member being of 'forged steel and said working chamber and the coacting forcing means being of cast iron.

3. An improved hot oil lpump comprising a housing made up ot' a central housing member, end covers therefor and plates arranged between the end covers and the central housing member orming compartments within the end covers separated by the plates from the space within' the central housing member, a Working chamber independent of the housing and arranged Within and opening into the central housing member, a shaft extending "Within the central housing member and a dischargepconnection extending through the central housing member and communicating with the Working chamber. l

4, An improved hot oil pump comprising a housing made up ot' a central housing member, end covers therefor and plates arranged between the' end covers and the central housing member forming compartments within the end covers separated by thei plates from the space Within the central housing member, a working chamber independent of the housing and arranged within the central housing membelga pair of shafts extending through the Working chamber and into the compartments in the end covers through bearings supported by the plates arranged between the end covers and the central housing member, one of said shafts having an operating extension projecting through one of the end covers, and a pair of coacting driven members arranged within the working chamber and on said shafts and adapted by rotation to force oil through the working chamber.

In testimony whereof, I have subscribed my name.

THOMAS DE ooLoN TIFFT.

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