US1958228A - Art of coking hydrocarbons - Google Patents

Description

May s, 1934.,

W. H. BEARDSLEY ART OF COKING HYDROCARBONS Filed May` ll 1931 Fig-.l

/7 /Z I: f6'

INVENTOR ATTORNEYS Patented May 8, 1,934

UNITED STATES PATENT oFFlcE-f ART F COKING HYDROCARBONS a corporation of Maine Application May 1, 1931, Serial No. 534,245

1 Claim.

This invention relates to improvements in the operation of systems for carrying out the combined vapor phase cracking of oils, such as gas y oil or kerosene stocks, for the production of low- 5 er boiling oils, such as gasoline, and the coking of heavy oils, such as crudes, topped crudes, flux oils, and other residual stocks and the like, by passing the hot vapor mixture from a vapor phase cracking operation, while still at high tempera- 0 ture, in intimate contact with a liquid oil mixture to be reduced to coke in a receptacle adapted to receive an accumulating charge of coke thereby comng this liquid oil mixture by the heat of the hot vapor mixture from the vapor phase l5 cracking operation.

The operation described in an application led February i9, 1929, Serial Number 341,214, by Harry L. Pelzer, is an example of such operations.

The vapor mixtures from vapor phase cracking operations are peculiarly difficult to handle prior to the separation of the tarry constituents which they normally contain as discharged, at temperatures upwards or" 950 F., from the vapor phase cracking operation proper. Characteristically these tarry constituents of such vapor mixtures tend to form deposits choking or plugging any stagnant spaces in lines or valves. The usual 'i' connection to two gate valves to connect one line to either of two other lines, for example,

3@ even where the legs of the T are very short and are connected directly to the gate valves, is not satisfactory for this purpose because, with the vapor mixture passing through either of the alternate passages, a deposit tends to form in the stagnant leg of the T rendering the operation of the valve system uncertain and irregular.

Two-way valves embodying plug-type closure members assist in the elimination of stagnant regions but in such service such valves tend to 49 freeze in one position or to become locked in 'one position due to the development of bridges. or' hard coke between the closure member and the valve body. lThis invention relates particularly to improvements minimizing such diiiiculties when such valves are embodied in systems for carrying out such operations.

A two-way valve adapted for the practice of the invention is illustrated in Figs. 1 and 2 ofthe accompanying drawing, Fig. 1 being a section 50 through the axis of the closure member of the valve and Fig. 2 being a section on line 2--2 of Fig. 1, a system embodying the valves illustrated in detail in Figs. 1 and 2 being illustrated, dia- A grammatically and conventionally, in Fig. 3. Referring to Fig. 3 of the drawing, the system illustrated may be operated as described in application Serial Number 341,214 previously mentioned, the connections 16 and 7 and the receptacles A, B, C and D corresponding to the connections and receptacles so designated in that ap- 60 plication.- The two-way valves in this system are shown in position to permit flow from the heater through connection 16 through receptacles B and C in succession to connection '7. To establish ow through receptacles C and D in succession, for example, two-way valves 20 and 21 are rst reversed and two- way valves 22 and 23 are then reversed. A similar operation establishes flow through receptacles D and A in succession, through receptacles A and B in succession, and so on.

These two-way valves, illustrated in detail in Figs. l and 2, comprise a frustro-conical rotatable plug 4 seated in a body 5. The body 5 is provided With three ports 6, 7 and 8, and the plug 4 75 is provided with two communicating ports 9 and 10 arranged so that by rotation of the plug port 8 can be connected either to port 6 or to port 7. Chambers 11 and 12 are provided in the body 5 at opposite ends of the plug 4, a valved connection 13 80 communicating with chamber l1 and a valve connection lll with chamber 12. In addition to the passage connecting the ports 9 and 10 through the plug 4, passages 15 and 17 are provided through the plug 4, these passages communicating with the chambers 11 and 12 through apertures in the opposite ends of the plug.

The `operation of the invention in the system illustrated in Fig. 3 will be illustrated by a specific reference to the valve 22. Assume a mixture of oil vapors at a temperature of l000-1020 F., for example, flowing from the heater through connections 16 and 24, through the valve 22 and through connections 25 and 27 to the coking receptacle B, the valved connections 13 and 14 be- 95 ing closed. To reverse the position of the valve 22 so that the vapor mixture will pass through connection 28 instead of connection 26, a cooling iiuid such as steam or a mixture of hydrocarbon gases high in methane at a temperature lower than that prevailing in the valve by a margin of 30D-400 F. or more is supplied through connection 13, passed through the passages l5 and 17 in the valve plug 4 and discharged through connection 14. The passage of this cooling uid through the passages in the valve plug is initiated just before it is desired to reverse the valve. This sudden cooling of the valve plug without corresponding cooling of the surrounding portions of the valve body frees the valve plug from its seat in the valve body and it is then rotated to the desired position, valved connections 13 and 14 closed as soon asthe valve plug is sumciently free from its seat in the valve body Any cooling iluid stable and inert ywith respet to the parts o! the valve with which it contacts at the temperatures prevailing in the valve and of sufiiciently high specific heat may be used in carrying out the invention. Steam and hydrocarbon gas mixtures high in methane are particularly useful in carrying out the invention.

I claim:

In the operation ot systems comprising a heater in which oil is heated to a cracking temperature upwards of 950 F., a coking receptacle in which heavy oil is Vreduced to coke by the heat of the hot oil products discharged from'said heater and a connection for discharging said hot oil products from said heater into said coking receptacle including a valve comprising a frustro-conical rotatable plug 'seated in a body provided with ports Vcommunicating with said connection, the im- WILSON HULL BEARDSLEY.

jiool dos

Images