US 2935391 A
Description (OCR text may contain errors)
May 3, 1960 TO PROPANE TRANSPORT LOADING E. W. EVANS ET AL APPARATUS FOR ODORIZING A PRODUCT WITHOUT ALLOWING THE ESCAPE OF THE ODOR TO THE ATMOSPHERE Filed Oct. 28. 1957 SUPPLY DRUM l2 l 6 P PROPANE VENT PRESSURE CYLINDER 3| 37 KEROSENE INVENTORS E. W. EVANS CHARLES MAC SPORRAN A TTORNEVS vAPPARATUS FOR ODORIZING A PRODUCT WITH- OUT ALLOWING THE ESCAPE OF THE ODOR TO THE ATMOSPHERE Edmond W. Evans and Charles MacSporran, Bartlesville, Okla.
Application October 28, 1957, Serial No. 692,744 4 Claims. c1. 48-195) This invention relates to an apparatus for adding odorizing agent to a product without allowing the escape of odor to the atmosphere. In one of its more specific aspects this invention relates to an apparatus which can be conveniently used by small loading stations to odorize fuels without contaminating the atmosphere.
It is common practice to add an odorizing agent in small quantities to normally odorless fuel gases which are either toxic or, when mixed with air, form explosive mixtures. Since fuels such as natural gas (methane) and liquefied petroleum gases (propane and butane) do not have appreciable odor of themselves, it is necessary to add odorizing agents, such as mercaptans, so that the presence of such materials in the atmosphere can be readily detected. In many operations stench is added to liquefied petroleum gas by adding the odorizing agent in metered quantities at bulk plants as the product is dispensed for delivery. Since such loading stations are generally located near communities, it is highly desirable to prevent the escape of odorizing agent to the atmosphere as a relatively small quantity of such materials can be highly objectionable to nearby residents. Many communities are becoming more and more aware of the danger of air pollution from industrial and commercial activities, and ordinances requiring control of such contaminants are becoming quite common. Constantly burning flares are satisfactory for large operations but are not practicable for small installations of bulk plant proportions.
According to our invention a method and apparatus are provided whereby odorizing agent, such as mercaptan, can be conveniently added in metered quantities to a fuel without contaminating the immediate atmosphere. The apparatus is particularly advantageous since it can be used by an operator of a small bulk plant without great expense or complex operating procedure. A pressure vessel is employed as intermediate storage for the odorizing agent and supply drums of odorizing agent are emptied through closed connections into the pressure vessel. The pressure vessel is then pressurized with a gas, preferably vapor of the fuel to be odorized, and the odorizing agent is transferred to a metering container which is vented into a second tank containing an absorbent for the odorizing agent. The absorbent tank is vented to the atmosphere and when the absorbent becomes saturated, the tank is disconnected and removed to a remote location for disposal of the absorbent. The metering container is isolated from the pressure cylinder and absorbent tank as it is emptied into the line carrying fuel to the transport or storage cylinders. In the preferred embodiment of our invention, mercaptan is used to odorize liquefied petroleum gas (LPG), and vented vapors are passed through kerosene before being released to the atmosphere.
It is an object of this invention to provide a method of odorizing a product without allowing escape of odorizu'ng agent to the atmosphere. It is another object to provide an apparatus which can be employed to add odorizing agent to a fuel in such a manner that the atmosphere is not contaminated with the odorizing agent. It is still another object of our invention to provide an apparatus which can be conveniently used by an operator of a small bulk plant to odorize liquefied petroleum gas with mercaptan without releasing objectionable odors. Other objects, advantages and features of our invention will be apparent to those skilled in the art from the following description, claims and drawing which shows schematically a preferred embodiment of our invention for installation at a small bulk plant loading station.
Materials which can be used as odorizing agents in our invention are well-known in the art and are commonly low molecular weight compounds of carbon and sulfur, generally in the 2 to 7 carbon atom range, such as ethyl mercaptan, propyl mercaptan, amyl mercaptan, dimethylsulfide, thiophane, or the like. Such materials can be absorbed in oily solvents having comparatively low vapor pressure, such as mineral oils, preferably light mineral oils such as diesel oil, furnace oil or kerosene. For the practice of our invention we prefer to employ kerosene because it is quite effective as well as being cheap and readily available.
To more fully describe our invention reference is now made to the attached drawing which shows an arrangement that can be conveniently provided for a small bulk plant loading station. Mercaptan odorizing agent is supplied in steel drum 10 which is unloaded, as shown by the drawing, by placing it on rack 11. Prior to positioning the drum on the unloading rack, its openings are plugged with valved connections 12 and 13, valved connection 12. including a T and valves 14 and 16, and connection 13 including valve '17. In this way any spillage is prevented as the drum is loaded onto the rack.
Flexible conduits 18, 19 and 20 are then connected to valves 17, 16 and 14, respectively. These conduits are preferably copper tubing. Conduit 18 communicates with pressure cylinder 21 through valve 22, line '23, sight flow gauge 24 and valve 26. Conduit 19 communicates with pressure cylinder 21 through valve '27, line 28 and valve 29. Flexible conduit 20 communicates with absorbent drum 30 through valve 31, conduit 32 and line 33 which extends into drum 30 below the surface of the absorbent contained therein. The absorbent is a light mineral oil, preferably kerosene. The vapor space of drum 30 is vented to the atmosphere through line 34 and valve 36.
To empty mercaptan from supply drum 10 the abovenamed connections are made and the valves opened. Any excess pressure in pressure cylinder 21 is vented through absorbent tank 30 so that superatmospheric pressure is not exerted within supply drum 1t). Mercaptan is emptied into pressure cylinder 21 by gravity flow, al-
lowing pressures in the supply drum and pressure cylinder to equalize throughconduit 19 and its connections. When supply drum 10 is empty, the cessation of fiow is determined by the sight flow gauge 24. Valves 22, 26, 27, 14, 16, 17 and 31 are then closed and the supply drum is disconnected.
Mercaptan is metered from pressure cylinder 21 by transfer through valve 37, line 38 and valve 39 to stench pot 40, wherein a definite quantity of mercaptan is measured by sight gauge 41. The transfer of mercaptan is made by pressurizing cylinder 21 with propane vapor entering through valve 42 and line 43 which contains pressure control valve regulator 44. A pressure gauge 46 is also provided in line 28. Transferring mercaptan with propane permits the stench pct 40 to be located near the loading spot and a considerable distance from cylinder 21 without necessitating pumps. Propane vapor thus forces the mercaptan to stench pot 40 which is vented to absorbent tank 30 through line 47, valves 48 and 49, and line 33. The stench pot at this stage is filled with petroleum gas heavily laden with mercaptan vapors. These are vented as mercaptan is forced into the stench pot. The vented vapors pass through the kerosene where the mercaptan is absorbed and thereby prevented from reaching the atmosphere. When a proper amount of mercaptan has been transferred to stench pot 40, valves 48, 49, 37 and 39 are closed and valves 50 and 51 in lines 52 and 53, respectively, are opened. Line 52 and line 53 having check valve 54 are connected to line 56 carrying liquefied petroleum gas to the transport or storage cylinder, not shown. Mercaptan flows from stench pot 40 by gravity into line 56. When the kerosene in absorbent tank 30 becomes saturated with mercaptan, as evidenced by slight odor issuing from vent line 34, tank 30 is disconnected and removed to a remote and safe location where the kerosene and mercaptan are burned.
Transferring the mercaptan from the pressure cylinder to the measuring vessel with LPG vapor enables simple but accurate flow control. Since the system is completely closed except for the one vent from the absorbent tank, the heavily charged LPG vapors present no problem. For flexibility two absorbent tanks can be provided so that one tank is always in operating condition.
As will be evident to those skilled in the art, various modifications of this invention can be made, or followed, in the light of this foregoing disclosure and discussion, without departing from the spirit or scope thereof.
1. Apparatus for adding odorizing agent to a product without escape of odor to the atmosphere comprising, in combination, a pressure vessel, first conduit means connected to said vessel for supplying odorizing agent to said vessel, means connected to said vessel for pressurizing said vessel, a metering container, second conduit means connecting said vessel with said metering container for transfer of a measurable amount of odorizing agent thereto, an absorbent tank containing an absorbent for said odorizing agent and vented to the atmosphere, a vent line connecting said metering container with said tank so that vapors vented from said metering container must pass into said absorbent, valve means in said vent line and in said second conduit means for isolating said metering container from said tank and vessel, and third conduit means connected to said container for transfer ring said amount of odorizing agent from said container to said product.
2. Apparatus for adding mercaptan to a normally odorless and gaseous fuel comprising, in combination, a pressure vessel, first conduit means connected to said vessel for passing mercaptan into said vessel, means connected to said vessel for pressurizing said vessel with vapor of said fuel, a metering container, second conduit means connecting said pressure vessel with said metering container for transfer of mercaptan thereto, an absorbent tank containing mineral oil absorbent and vented to the atmosphere, a vent line connecting the upper portion of said metering container with said absorbent tank, said 4 vent line extending into said mineral oil, valve means in said second conduit means and in said vent line for isolating said metering container from said vessel and tank, and third conduit means connecting said metering vessel to a main line carrying said fuel for transfer of mercaptan of said fuel.
3. Apparatus for odorizing a given amount of liquefied petroleum gas with mercaptan without allowing mercaptan to escape to the atmosphere comprising, in combination, a pressure vessel, first conduit means closably connected to said pressure vessel for draining mercaptan from a supply drum into said pressure vessel, means connected to said vessel for pressurizing said pressure vessel with propane, a metering container, second conduit means connecting said vessel with said container for transfer of a measured quantity of mercaptan thereto, an absorbent tank containing kerosene and vented to the atmosphere, a vent line connecting the upper portion of said metering container with said absorbent tank, said vent line extending into said kerosene, valve means in said second conduit means and in said vent line for isolating said metering container from said vessel and tank, a liquefied petroleum gas transfer line, and valved conduits connecting the upper and lower portions of said metering container to said transfer line for draining said quantity of mercaptan thereinto.
4. Apparatus for odorizing a given amount of liquefied petroleum gas with mercaptan at a loading station without contaminating the atmosphere in the vicinity with mercaptan comprising, in combination, a pressure cylinder, a mercaptan supply drum, valved connections on the upper and lower portions of said drum, two flexible conduits connecting each of said valved connections with said pressure cylinder, a portable absorbent tank containing kerosene and vented to the atmosphere, a third flexible conduit connecting the upper portion of said drum with said tank, a propane line having a pressure control regulator connected to said pressure vessel and a source of pressurized propane, a metering vessel having a sight level gauge, a valved transfer line connecting the lower portions of said cylinder and said vessel, a valved vent line connecting the upper portion of said vessel with said tank, said vent line extending into said kerosene, a main conduit for transfer of liquefied petroleum gas, and valved drain lines connecting the upper and lower portions of said vessel with said main conduit to permit gravity addition of mercaptan from said vessel to said liquefied petroleum gas flowing in said main conduit.
References Cited in the file of this patent UNITED STATES PATENTS Jones July 20, 1937 Rutherford Nov. 4, 1941 Wissmiller Sept. 23, 1952 OTHER REFERENCES ors UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION f Patent No, 2 935391 May 3,, 1960 Edmond We Evans et al9 It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below,
In the grant, line's 1 2 and 3 for "Edmond W, Evans and Charles MacSporran of Bartlesville, Oklahoma read Edmond W. Evans and Charles, MacSporran of Bartlesville Oklahoma assignors to Phillips Petroleum Company, a corporation of Delaware, line 12,, for Edmond W, Evans and Charles MacSporran, their heirs" read Phillips Petroleum Company its successin the heading to the printed specification lines 5 and 6 for Edmond W. Evans and Charles MaoSporran Bartlesville, Ok1a.""'= read Edmond W, Evans and Charles MacSporran Bartlesville Okla assignors to Phillips Petroleum Company, a corporation of Delaware Signed and sealed this 13th day of December 1960. (SEAL) Attest:
KARL H, AXLINE ROBERT' c. WATSON Atte sting' Officer Comnisisioner of Patents