US1615481A - Tube-still control - Google Patents

Description

Jan. 25, 1927. 1,615,481

F. M. POOLE TUBE STILL CONTROL Filed Jan. 2, 1926 Mantra! NIL on. LIN! INVENTOR Patented Jan. 25,, 19227.,

UNETEVD STATE.

a 1.615381 ear-eur- OFFIC;

FOSTER M. POOLE, OF TULSA OKLAHOIIMIA, ASSIGNOR TO THE BROWN INSTRUMENT COMPANY, OF PHILADELPHIA, PENNSYLVANIA, A CORPORATION OF PENNSYL- Application filed January a, 1926. Serial No.

The general object of the present invention is to provide a simple and effective method of and means for controllingcombustion conditions in an oil refining tube still in such manner as to secure the proper oil heating effect while maintaining efficient combustion. conditions in the still furnace.

The invention is characterized by the fact that the general rate of combustion is made responsive to the heat requirements of the still, and the ratio of fuel and combustion supporting air supplied to the furnace is made dependent on the composition of the flue gases, and that this result is obtained with the use of simple and effective instrumentalities which may be of standard commercial types. .ln carrying out my invention, T provide means for regulating the supply of fuel to the still combustion chamber and provide other means for regulating the supply of combustion supporting an to said chamber, and provide means for adjusting one of said supply regulating means in automatic response to the changes in the vices; and

temperature to which theoil is heated, and provide means for adjusting the other supply regulating means in response to changes in the composition of the flue gases leaving the furnace.

The various features of novelty which characterize my invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention, however, its advantages and specific objects attained with its use, reference should be had to the accompanying drawings and descriptive matter in which l have illustrated and described preferred forms of ap paratus for use in carrying out the invention.

@fthe drawings:

Fig. l is a diagrammatic representation of an oil refining tube still relating de- Fig. 2 is a view taken similarl to Fig. 1 showing a portion of a tube stil equipped with a modified form of regulating means; and

l 'ig. 3 is a diagraatic representation of the electrical connections of the gas analysis apparatus. e

In Fig. l l have diagraatically illustrated an embodiment of the present invention including a tube still A of conventional type. As shown the tube still A comprises a TUBE-STILL CONTL.

combustion chamber A beneath a bank of horizontal tubes B'which are swept by the heating gases passing from the combustion chamber A to the furnace stack outlet A The tubes B are connected at their ends so that the oil passes successively through tubes B at successively lower levels from an oil inlet B to an oil outlet B The oil to be refined is supplied to the inlet B by a fuel pump C, which, in the preferred mode of use contemplated by me, 1s operated to supply oil to the. still at a constant rate.

Fluid fuel, which ordinarily is oil, is sup- )lied to the combustion chamber A through urner nozzlesD. The burner nozzles D receive fuel from a suitable pressure source (not shown) through a supply pipe D at a rate depending on the adjustment of a fuel supply regulating valve D Air for combustion is supplied to the combustion chambers! through supply pipes receiving air from the outlet F of a blower F at a rate dependent on the adjustment of a blower regulator ll which, when the blower is turbine driven as contemplated in the particular ,arran ement shown in Fig. 1, is a valve in t e pipe F supplying impelling steam to the blower.

In accordance with the present invention the valve D is adjusted to increase and decrease the supply of fuel to the combustion chamber as the temperature to which the oil is heated in passing through the tubes B falls below or rises above a predetermined temperature. This result is obtained. with the form of construction illustrated by means of a reversible electric motor G energized for operation in one way to increase the supply of fuel-and in the opposite direction to decrease the supply'of fuel by means of a pyrometer controller H which is responsive to the temperature to which a thermo-responsive device I is subjected. As shown the thermo-responsive device l is a thermo-couple inserted in a thermometer well 13 in the path of oil flow at or adjacent the still outlet B The terminals of the thermo-couple are connected by conductors 8 and 9 to corresponding terminals of the pyrometer controller ll. .As shown, one

terminal of the motor'G is connected by a conductor 3 to the conductor 2 of an electric current supply or power circuit. The contill troller H operates in response to the potential developed by the thermocouple I to connect one terminal 6 of the motor G to the conductor 1 of the power circuit through controller H connects a second terminal 5 of the 'motor Gr to the conductor 4 and thereby to the supply conductor 1, and thereby causes the motor G to rotate in the direction to open or increase the flow through the valve D The pyrometer controller H may be of any usual or suitable form of instrument for the purpose. In general, it includes a voltmeter having its terminals connected by the thermo-couple I, and includes a switch mechanism controlled by the voltmeter pointer and serving to connect the motor terminal 6 to the conductor 4. when the oil temperature is above the predetermined value and to connect the motor terminal 5 to the conductor 4: when the oil temperature is below the predetermined value. The switch mechanism in an instrument of this type is ordinarily actuated by a motor or other relay which may be energized from the supply conductors l and 2 through the conductors 6 and 7. T have not thought it necessary to illustrate and describe in detail the construction of the pyrometer controller H, for the reason that the present invention does not depend on the specific form of the controller and various forms of control instruments suitable for the purpose are known. For example, the controller H may be of the type disclosed in the patent to iFrown No. 1,355,44E8, granted October 12,

In accordance with the present invention the supply of air for combustion to the combustion'chamber A to the furnace inlets E is regulated to maintain a desirable and approximately constant flue gas composition. 11 the arrangement shown in Fig. 1, this regulation is obtained by means .of an electrical flue gas analyzing system including a 00 controller HA which directly controls the motor GA to increase and diminish the air su plied by the inlets .E accordingly as the C 2 content of the flue gas falls below or rises above a predetermined value. The

flue gas analyzing .means may be of an .usual or suitable type. As diagrammatical'ly illustrated, it is of the known type in which a small stream offluegas iswithdrawn from the furnace adjacent the stack outlet through a sample tube L, condenser M, filter and an electrical gas analysis cell device K y an aspirator O in which water supplied by a pipe P serves as the impelling fluid. As shown,- the pipe P passes water into the cooling water space of the condenser M, and the water passing from said space to the aspirator through a pipe P. In the known type of gas analysis apparatus conventionally illustrated in Fig. 1, the diiterent thermal conductivities of the flue gas and of a standard or comparison gas, which ordinarily is air, in cells of the device K, give dilterent temperatures and thereby diflerent resistance values to resistors forming a part of a suitably energized Wheatstone bridge. In the diagrammatic representation of Fig. 3, K represents the standard or comparison cell containing a resistor r and air or other standard gas by which heat result ng from the current flow through the resistor r is conducted to the metal wall of the cell K. K is the test gas cell of the device K and has located in it a resistor r. The cells IQ and the resistor 1* may be identical with the cell K and the resistor 9" except that the cell K is normally sealed after being filled with air or other comparison gas, while the cell K is formed with ports K for the influx; and efiluzr of flue gases. The resistors 9 and 1" are connected into a Wheatstone bridge of which they form two arms. The other two arms of the bridge are formed by so-called balance resistors R and R. K represents a source of current for energizing the Wheatstone bridge. The bridge potential difference varied by temperature variations of said resistors r and 1" is transmitted by the conductors and to the CO controller HA. The controller HA may be identical in construction and mode of operation with the controller H, and operates the motor GA to increase and decrease the su 1y of air in response to changes in the C6? content of the flue gases inexactly the same manner as the controller H operates the motor G in response to changes in the temperature of the oil to which the thermocouple I is subjected. The connections between the controller HA, the motor GA, and the ower circuit conductors l and 2 include con uctors 30, 40, 50, 60, and 70, corresponding respectively to the conductors 3, 4, 5, 6, and 7.

In the normal intended operation of the apparatus shown in Fig. 1, oil is passed at 'a constant rate through the still tubes and is therein heated to the desired final delivery temperature. The fuel is sup lied at the exact rate required to provide 1; e' necessary heating effect, and the air supply is regulated to insure. the desired .efliclency of combustion. The simple and eflective regulat ing provisions thus insure a uniform thermal efliciency which ma be the maximum practically obtainable. he actual thermal efliciency obtained will depend, of course, upon conditions such as the character of the fuel burned, and the weight of heating gases per' pound of fuel burned considered I esirable in order to insure the desired rate of heat absorption by different portions of the heat absorbing the surface, and the desirabi lity of avoiding temperatures tending to local overheating of-any portion of the tubes B- The rate at which the oil to be heated is supplied to the. tubes B depends on the speed of the ump C and'the latter may be provided wit -h any suitable manual or automatic speed control means. While I contemplate a nonfluctuating or constant oil feed to the tubes B,*the rate at which the oil to be heated is supplied may be varied in response to changes in conditions, such as the progressive building up of carbon deposits on the inner walls of *the tubes B which occurs between periods in which the latter are cleaned. w

Inlieu of controlling the composition of the flue gases by directly regulating the air supplied to a furnace operated with forced draft, as, shown in Fig. 1, other means may I claim as'new and be employed to secure the same control of the flue gas composition. For example, as

shown in Fig. 2, in a furnace operating with a stack draft, the stack damper S: may be adjusted as through a belt R by a motor GA 7 controlled in the same manner as is the motor GA of Fig. 1.

Having now described my invention what desire to secure by Let ters Patent is: p

1. In heating oil to a refiningtemperature in a tube still, the improvement whlch consists in maintaining an approximately constant oil temperature at the still outlet by regulating the relative rates at which oil is passed through the tube still and at which fuel is burned to heat the still in automatic response to said oil temperature, and maintaining efiicient combustion conditions by fuel supplied at a rate varying with the temperature to which the oil is heated as required to maintain said temperature approximately constant and supplying air for the combustion of the fuel as required to maintain an approximately constant flue gas composition.

3. Anoil refining still comprising a combustion chamber, tubes heated by the combustion of fuel supplied to said combustion chamber, means passing the oil to be refined through said tubes at a predetermined rate, means responsive to the temperature at which the oil is heated regulating the supply of fuel to said combustion chamber, and

means responsive to the coinpositionof the gaseous products of combustion formed in said combustion chamber regulating the supply of combustion supporting air to said combustion chamber.

Signed at Philadelphia, in the county of Philadelphia and State of Pennsylvania, this 28th day of December, A. D. 1925.

. FOSTER M. POOLE.

Images