US2636490A - Hot oil heater and circulator - Google Patents

Description

April Z8, 1953 w. J; MILLE I 2,636,490

HOT OIL HEATER CIRCULATOR Filed Nov. 14. 1950 2 SHEETS-SHEET 1 TIT-gpl..

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April 28 1953-" w. J. MILLER HOT oIL HEATER AND 'cI'RcULATo`R- :LTS-SHEET 2 Filed Nov. 14, 1950! Patented Apr. 28, 1953 UNITED STATES PATENT OFFICE HOT OIL HEATERV AND CIRCULAIOR William J. Miller, Youngstown, Ohio Application November 14, 1950, Serial No. 195,564

This invention relates to hot oil heaters and circulators for use with asphalt storage tanks, tank cars, etc., and any and all applications wherein asphaltic or bituminous materialsv must be heated to maintain the same in fluid condition for handling purposes.

The principal object of the invention is the provision of a hot oil heater and circulator for the efficient heating and handling of a uid heating medium.

A further object of the invention is the provision of a hot oil heater incorporating novel heatexchange means.

' A still further object of the invention is the provision of a hot oil heater and circulating device including interconnected storage, heating and surge tank portions for aiiuid heating medium and circulating means for moving the fluid heating medium therebetween.

A still further object of the invention is the provision of a hot oil heater and circulating device including means for circulating a iiuid heating medium from a heating portion of the device to and from an object to be heated.

It is known in the art that various storage tanks, transportation tank cars and the like for asphaltic and bituminous materials are commonly supplied with heat exchangers through which it has been customary to circulate steam from a permanent or portable steam boiler installation and for the purpose of maintaining the asphaltic or bituminous materials in fluid or semi-huid condition.

The present invention relates to a specic form of hot oil heater and circulating device which can be used primarily as a portable heating unit for supplying heat to storage and/ or transportation tanks of asphaltic or bituminous materials such as commonly used in connection with road paving jobs and particularly asphaltic concrete constructions. The hot oil heater and circulator disclosed herein is constructed as a 7 Claims. (Cl. 126-3435) vice from an outside point; pumped from the storage portion of the device to the surge tank to increase storage capacity; pumped from the heating unit of the device to the surge tank thereof; pumped from the work served and the connecting lines so as to empty the same; and

compact, relatively small unit entirely self-sufpumped from the supply tank to the surge tank of the device under automatic control to maintain a desired level.

With the foregoing and other objects in view which will appear as the description proceeds, the invention resides in the combination and arrangement of parts and in the details of construction hereinafter described and claimed, it being the intention to cover all changes and modiiications of the example of the invention herein chosen for purposes of the disclosure, which do not constitute departures from the spirit and scope of the invention.

The invention is illustrated in the accompanying drawing, wherein:

Figure 1 is a side View of the hot oil heater and circulator.

Figure 2 is an end view of the hot oil heater and circulator.

Figure 3 is a vertical section taken on line 3--3 of Figure 2.

Figure 4 is a schematic diagram incorporating interconnecting fluid flow lines.

Figure 5 is a wiring diagram.

By referring to the drawings and Figures 1 and 2 in particular it will be seen that the hot oil heater and circulator comprises a storage tank l0 forming a base having the upper portion thereof formed in a transverse arc or concave surface whereby a longitudinal channel is formed for the reception and positioning of a cross sectionally circular heating unit Il. The upper portion of the storage tank l0 thereby partially encircles the heating unit Il as the heating unit Il is, in eifect, nested in the upper portion of the storage tank and approximately one-third of its area is in engagement with the storage tank. The heating unit Il supports a horizontally positioned flat surge tank I2 positioned directly above the heating unit and closely spaced with respect thereto so as to form a radiant and thermal heat baffle with respect to the upper surface of the heating unit Il and thereby increase the operating efciency `thereof. Several intercommunicating pipes are arranged between the storage tank I0, the heating unit Il and the surge tank l2 as will be hereinafter more fully described.

A projecting end section i3 of the tank l0 forms a platform supporting a main circulating pump I4, a motor I5 coupled thereto and a secondary circulating pump I6 having a motor II coupled thereto for driving the same. The main circulating pump I4 has its inlet I8 in communication with a pipe I9 which in turn communicates with the uppermost portion of the heating unit I I and an outlet 2Q which is adapted to be connected t-o the work to be heated such as a heat exchanger in a tank of asphaltic material. The heating unit II has a. pipe 2I` in connection therewith through which the liquid heating medium circulated by the pump i4 is returned to the hot oil` heater. By referring to Figures 1 and 3 of the drawings it will be observed that this' pipe ZI' communicates with the lowermostportion of. the heating unit II.

By referring to Figure 3 ofthe drawings it will' be seen that the heating unit II comprises a. double walled tank, the inner wall of which is indicated by the numeral 22 and forms a horizontally" disposed tubular passageway from one end or the heating' unit II' to the other; The chamber formed' between the outer wall of thek heating unit iI and' the inner wall 22 is indi'- cated by the numeral 23 and will thus be'seen tok completely surround a combustion chamber 24" which'isy dennedby the inner wall 22.

' A fuel' burner" 25 is positioned at one endl of the device and discharges fuel through a nozzle 2E' into the chamber 24. The nozzle 26' isy posit'io'n'edl through an end closure 2'! which is double walled and insulated" and the whole of which is removably mounted onl the heating unit II as by 'studs 2t which. are afxed thereto. A stack' 29 isA located' at the opposite end ofthe device and extends vertically through the liquid' chamber 21 and establishes communication between the combustion chamber 24. andthe atmosphere.

A pair of spacedlvalved pipes establish com munication'between the surge tank I2 and the, chamber 23 and also serve as legs supporting the hat surge tank I2 i'n its position immediately above. the heatingA unit II. A third supporting pipe 3|* is also 1: rovi'd'ed`v for positioning and. supporting, the surge tank. l2 and' itY is in coinmunication with theY liquid chamber 23 of" the heating unit II and with the surge tank I2'. By rei'erring'to Figure 3' of the drawings pipe 3'I1wi11 be seen to extendupwardly in the surge tank I2l to a point even with the uppermost wall thereof and' inmediately Within a dome 32".

i A pair of' circular aperturedl bafes 334-33 are positioned on a movable support 34' in the combu'stion chamber 24 and are. adapted'to bemoved longitudinally thereof so that products of' com'- bustion` introducedv into the coiri'bustion chamber' 24. through` the nozzle 2'6 will' be directed by the baffles for suitableV impin'gement, with the inner wail" 22 to facilitate the heat transfer intol the liquid heatingA medium in the chamber 23'.

By referring again to Figures 1 and12 of.` the drawings it will be seen that a pipe 35 com-- 'municates with the storage tank` IiiA and with the surge tank I2 and extends' upwardly'theree into to a point` near the upper'wall thereof. A pipe' 36' connects` the surge tank'. I2 with a fourway` valve 3f!" controlling the output ofthe second'arypump I G heretofore referred to and a pipe 38Lv connects thefoureway valvel with the pipe Iilat` a point adjacent the` inlet I8` heretofore referreol toj and between the" said inlet i8' and' a' valve 39' controlling the pipe I 9. Another pipe All"extenus'irom` the four-way valve'3i' tothe pipe 2 I, heretofore mentioned; as forming the' inlet to the heating unit li and as best illustrated in the schematic view comprising Figure 4 of the drawings.

A fourth pipe 4I extends from the four-way valve 3i to the storage tank I0 so that the liquid medium employed may be moved from one p0rtion oi the device to another by the secondary pump iii. 'For example, when it is desired to initially fill the device with a suitable liquid medium, a valve.- @2 in the pipe' 38- is. closed and a valve. i3 controlling a 'i 4E communicating with the piping 3S adjacent the valve 31 is opened, the Valve t3 being in communication with a source of suitable liquid. Operation of the secondary pump I-`5 will then pump liquid from the supply source (not shown) through the valve 43,

` the T lili, the pipe 38, the four-way valve 31 and .35 into the surge tank I2 and from there through the connectingpipes 3U, assuming' that the valves normally' controlling these lines are open'. Thus the entire uuid capacity' of the devicel may be unused, for example, in transporting theV same to any indicated location and thereby enabling it to carry along the necessary amount of the liquid heating medium;

Upon changingv the setting; of the fourhway valve Si when they deviceN is in` operation and' in communication with a heat exchanger tnot'illus trated) the' secondary' pump I 6' operatesv to move liquid from the storage tank It by way of the pipes #3i and 3e to the surge tank Ii2 where it is" in normal communication: with the heating unit II- and' may thus beused to replenish the liuuicl medium required to fill the connecting piping and'. the heat exchanger. It will thus be seen thatv when the device is. in opera-tion and the main circulating pump I"4` op'- erating; the' liquid heating mediinn' will be conti'nually'withdrawn from thetop of the heating unit' II', circulated through the heat exchanger and returned to the' heating unit through the pipe' ZI. In theevent of loss of liuuiii heatingmedium' in the corn'iecting piping' or' heat. exchanger, theA heretofore described' action ofc the secondary pump Ifiiwill" withdrawY liquid from the storage supply' tank lil and replenish the liquiclv in the actuall treating systemw circuit. Means for controllingv this operation: automatically is provided and` comprises; a. double acting' control device; $5', the same being' actuated by afloat 46 in the surge' tank I2 so that upon the loweriiigA ofthe level' ofi' the liquid medium in the surge tanlr i2'. the secondary pump. it will' be automatically actuated to replenish the same as heretofore described and' simultaneously the burner. 25" will be shut'v down until 'such time as the liquid level in the surge tank is again normal at which time the' control H5' willl stop theY secondary pump r6 and' reeenergize theburner 25;

Shesecondarypump I "6' is also used` at' the' time' the device'is disconnected' fromy the' heat exe changer as it maythen be emplom-zd'l for )withi drawing the liquidmedium'- from the. heat eind changer and connecting pipingby-wayfor'thepipe 381 discharging' the same throughQ thel pipes 4I or Se into the device so that* the completeliuuid medium mayagain be retained bythe device and'y no` additional storage tan-ksl are necessary; Thisv operation is accomplished byy closing the' valve 39y in the pipe reopening the valve t2 i'n the pipe 3'8" andclosing the valve 43 and settingl the'ffour'- way'valvel 31" so that action'othesecondarypump I8' movesliquidffrom the pump I4 and the connecting piping intoth-e storage tank I and/or surge tank I2 of the device which may then again be completely relled and the same utilized as storage capacity. Alternately the liquid heating medium may be pumped from the device and its connected lines to a remote storage tank by way of the T i4 and'valve 43. f

It will thus be seen that the hot oil heater and circulator comprises a completely self-contained unit capable of supplying itself with liquid heating'medium, moving the same from storage to heating portions thereof as needed, and that'it also includes an eiicient heating unit and circulating means for heating the liquid heatingmedium used and circulating the same through' a heat exchanger in an area to be heated. The elciency of the heating portion of the device is enhanced by its design and arrangement and particularly with respect to the partial envelopment of the heating unit I I by the storage tank l0 and the'isurge tank I2. The movable baiiles 33-33 enable the flame from the burner to be impinged on the inner wall 22 of the unit I I so as to result in a rapid heat transference to the liquid medium in the chamber 23.

It will be observed that the return flow of the circulating liquid medium is into the lowermost portion of the heating unit I I and that the withdrawal of the heated liquid medium is from the highest point thereof. This insures continuous circulation of the liquid heating medium through the device and about the inner wall 22 thereof. The orifices in the baffles 33 contribute to the over all efficiency of heat transfer of the device and furthermore permit visual control of the burner 25 through a peephole formed in a closure aiilxed to the opposite end of the unit with respect to the burner 25.

It will be observed that the burner 25 is supported on the end closure 27 and in completely elevated relation to the driving motors l 5 and I 'I and the main and secondary pumps I4 and I6 to provide ready access thereto. The device is also -provided with a temperature limiting control 48 electrically -connected in the circuits controlling the burner 25 so that upon the liquid heating medium reaching a predetermined temperature the burner is automatically shut down. The burner 25 is of a type known in the art and includes a motor driven fuel oil pump, carburetor and blower for processing the fuel before delivering the same to the nozzle 26 and the combustion chamber 24 as heretofore described.

The entire device is of compact construction and occupies relatively small space and is therefore adapted to be mounted on a trailer, thus rendering the same portable. The control 48 is also arranged to operate the burner 25 to` maintain desirable operating temperatures at between 300 F. and 375 F. in the chamber 23.

It will thus be seen that the hot oil heater and circulator disclosed herein meets the several objects of the invention.

Having thus described my invention, what I claim is:

l. In a hot oil heating and circulating device the combination of a storage tank, a heating unit and a surge tank positioned above and supported by the heating unit, the storage tank and surge tank partially covering the lower and upper portions of said heating unit, a combustion chamber in said heating unit, a principal circulating pump, tubular connections between said heating unit and said principal circulating pump and together therewith constituting means for circulating a liquid medium from said heating -unit toa place of use and return to the heating unit through said tubular connections, secondary tubular connections establishing communication between the storage tank and the heating unit and the surge tank and a secondary pump for moving the liquid medium therethrough, a valve in said secondary Itubular connections, said valve comprising a fourway valve interconnecting said secondary tubular connections and said secondary pump, and flow control valves in siad secondary tubular connections between said ysecondary pump and said heating unit,"` a third vset of tubular connections between said surge tank and said heating unit and burner means for introducing and maintaining a combustible mixture in the said combustion chamber of said heating unit. l

2. The apparatus set forth in claim l and further characterized by control means on said surge tank responsive to the liquid level therein. said secondary pump being responsive to said control means in moving liquid from said storage tank to said surge tank.

3. The apparatus set forth in claim l including control means in said surge tank for said burner means and the secondary pump, said burner means being responsive in operation to said control means and said pump being responsive in operation to said controlmeans whereby liquid from said storage tank may be moved to said surge tank and whereby the said burner means is responsive to the liquid level in said surge tank.

4. A hot oil heater and circulating device including a double walled heating unit defining a longitudinal combustion chamber and an annular liquid chamber, means for introducing and maintaining a combustible mixture in said combustion chamber, a surge tank positioned over said heating unit and acting as a thermal baffle with respect thereto, means establishing communication between said surge tank and said liquid chamber, the liquid chamber being provided with inlet and outlet orifices, a principal circulating pump, a tubular connection between said principal circulating pump and said outlet orifice whereby liquid heating medium may be circulated through the device and a place of use, a storage tank supporting said heating unit and partially enveloping the same, a secondary pump, communicating means connecting the said storage tank and the said surge tank whereby liquid heating medium in the said heating unit and surge tank may be maintained by pumping from the said storage tank, and control means in said surge tank responsive to the liquid level therein for controlling said secondary pump.

5. A hot oil heater and circulating device comprising a storage tank having a longitudinally extending transversely arcuate concaved top portion, a cylindrical heating unit positioned on said storage tank and resting in the concave top portion thereof so as to be partially enveloped by lthe said top portion of the said storage tank, said heating unit having a tubular core disposed longitudinally therein in spaced relation to walls of the heating unit and dening a combustion chamber within the same, the space between the said tubular core and the walls of the cylindrical heating unit being closed at its ends and forming a liquid heating chamber, a stack in communication with said combustion chamber at one end of the device, a fuel burner in communication with the combustion cham- #man ber at. the otiier'ndf @i the devic, as surge. tam. in communica/mn with said liquid heating Gili-amber :mi` posiiioned immediately aboveV the said Ixeamizig mini. saidy surge tank hav-ing a horizontaliy fiati botomf acting as; a, radiant and thermal name with respect' to: this cyiimiricfai heating unit, and means establishing' comuni.- caticm aeimzeank the surge tank'. mida the storage tank. iiiclmiing cnn-duits: and a,y pump for trans iring a liquid heating" medium. from: one por tion. ofv the device to smother? whereby ai desi able: liquid: kwel may' be maintained in. time` Iiq@ uid heating hamber anni th@ sume trmm 6; 'nie het. @ii heater: circulating: device as sei ferm in eiaim `5: including a, liquid; lavei responsivecontr'ol in sid surge tank', th said pump being responsive;I in Qperatioiil to the said liquidv level responsive. contrai.

7i. The hot' oil heater and circuiatingrdevice as seis forth in claim 5 wherein. the cylindriai heating unit is formada with inlet' and outlet. ori Haes emmuiicating with. theliquid chamber;

and a. circulating pump cammumication with eine of: saidori'ces: whereby liquid; the. said liquid heating chamber may' be. delivered tiav a place of user and returned: tiifaugh tlm @ther une si saidl rificest,

WILLIM J.

References Cited in the fil-2 0f this patent NITEDSTATES PATENTS Number NameA Date 969,221' Thompson Segui; 6, 1910 1572554121 Neal N munn Aug.. '20x 1929 l,.190,55 Plumb Jan. BTL. 1931 1,975,433 Rhodes *hummm* Oct.. 2; 1934 2,046,098: Vance et al... June 30,1936 2,5`06g412 chausse' May 2, 1950 FOREIGN PATENTS Nuinbr Country Date 2492;,3'0'4 Greet' Britain Mar. 25 1926 7005805 France --.i-w Jari. 2, 1931

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