US2830041A - Method for refining oleo-resinous material - Google Patents

Description

A ril 8, 1958 MOGARVEY CLINE 2,830,041

METHOD FOR REFINING OLEO-RESINOUS MATERIAL Filed March 24, 1952 8 Sheets-Sheet 1 FIG. I

Inventor Mc Gprvey Cline V /f v m By Attorneys."

Apl il 8, 1958 MOGARVEY cum: 2,830,041

METHOD FOR REFINING CLEO-RESINOUS MATERIAL Filed March 24, 1952 a Sheets-Sheet 3 Inventor Mc Gdrvey Cline,

y -w %?10' n eys' April 8, 1958 MCGARVEY CLINE- 2,830,041

METHOD FOR REFINING OLEO-RESINOUS MATERIAL Filed March 24, 1952 s Sheets-Sheet 4 'I 4 FIG. 3 I

To Exhaust Pump. 4/ /6 lnven tor Mc GARVEY CLINE,

By W1 METHOD FOR REFINING OLEO-RESINOUS MATERIAL Filed March 24. 1952 April 1958 MOGARVEY CLINE 8 Sheets-Sheet 5 Inventor Mc GARVEY CLINE,

April 8, 1958 2,830,041

METHOD FOR REFINING OLEO-RESINOUS MATERIAL M GARVEY CLINE 8 Sheets-Sheet 6 Filed March 24, 1952 FIG. I3

. Inventor Mc GARVEY CLINE,

torney's.

2,830,041 METHOD FOR REFINING YOLEO-RESIINOUSI MATERIAL Filed March 24, 1952 April 8, 1958 McGARVEY CLINE 8 Sheets-Sheet 7 FIG .7

Inventor Mc GA RVEY CLINE By i mw METHOD FOR RQFINING OLEO-RESINOUS MATERIAL Filed March 24, 1952 April 1953 MCGARVEY CLINE 8 Sheets-Sheet 8 FIG. IO

Inventor Mb GARVEY CLINE,

United States Patent O,

METHOD FOR REFINING OLEO-RESINOUS MATERIAL McGarvey Cline, Jacksonville, Fla.

Application March 24, 1 952, Serial No. 278,190 8 Claims." (01. 260-109) This invention relates to methods of and apparatus for purification of pine oleo-resins and separation of valuable constituents thereof. More particularly, the invention relates to improvements in the treatment of crude pine oleoresin aggregates whereby aqueous (liquid) and solid contaminating materials are advantageously removed.

As noted in U. S. Patents Nos. 2,140,511, 2,140,514 and 2,400,040, the general composition and characteristic nature of crude pine oleo-resins as delivered from the forests to processing plants are well known. These patents describe the handling and processing of crude oleo-resins by means and methods that have proven to be peculiarly successful and effective in the improvement of yields and grades of pine tree eXudates. In purification processes in use and in connection with processes set forth in such prior patents, crude oleo-resins have been collected in batches which, upon settling for sufiiciently long periods, have been separated into a plurality of layers because of the diiferences in the specific gravities of the various materials in such batches. Agents have been employed to secure a desired difference in specific gravity to promote separation of desirable components of the aggregate crude mixture from the undesirable components, as for instance, (1) by thinning the oleo-resinous portion of the aggregate with turpentine to render the oleo-resin portion lighter than water and thus efiecting separation of aqueous material; and (2) by adding salt or other high specific gravity material to the water used in processing to render the water heavier than the oleo-resin portion and thereby obtaining effective separation of the aqueous material.

The improvements obtained by such agents have been notable in the brilliance of the rosins and in the freedom from extraneous contaminating materials which had been commonly present in gum rosins produced in the old fire stills. In other respects, however, the variables involved in processing batches of crude oleo-resin have been difiicult to control to a degree adequate or operative for the production of gum rosins of uniform physical and chemical properties. A chief reason for this lack of uniform- .ity'is thought to be the lack of uniformity in the separation of water and water-soluble materials from the crudes prior to charging the oleo-resinous materials into a still for separation into rosin and turpentine.

It is difficult to obtain a wide difference in the specific gravity of oleo-resinous material and of water by thinning with turpentine which has a specific gravity of 0.867. 7

Furthermore, in batches of the size customarily treated, and with the degree of thinning commonly used, from eight to ten hours are required to accomplish a desirable separation of. aqueous material from oleo-resinous material by sedimentation.

The efiiciency and uniformity of sedimentation are materially affected by the variable temperature conditions of the material being processed. Considerable time is required to fill a settling tank, and each successive charge thatis introduced from a melter into. altanloremains in a layer on top of a layer formed by a preceding charge. The first charge introduced into a settling tank, tends to remain in the bottom of the tank because of its decreasing temperature and increasing specific gravity. The viscosity of oleo-resinous aggregates increases very rapidly as the temperature of the aggregate decreases. This is the case even with aggregates thinned with turpentine to a degree that the turpentine constitutes 35% of the aggregate by weight. The settling in batch tanks is also adversely affected by convectional currents induced by the loss of heat from the vertical surface of the tanks. In addition, there is the efiect of atmospheric conditions, becoming most adverse to good sedimentation in cool weather.

An object of the present invention is to provide improvements in methods of and means for purifying pine oleo-resins, and more particularly oleo-resinous aggregates collected from pine trees.

Another object is to provide methods and means by which it is possible to obtain an improved and a more uniform separation of aqueous material from oleo-resinous aggregates, and by which such separation can be accomplished in a continuous manner.

It has been found in connection with the invention, that water and oleo-resin aggregates become increasingly incompatible, particularly at relatively high temperatures, and at superatmospheric pressures. Also, it has been observed that the coefiicients of cubical expansion for oleoresinous products, such as rosin and turpentine, are higher than the coefiicient of cubical expansion of water. Ad vantage is taken of these differences so as to obtain a separation of aqueous matter from oleo-resinous aggregate without the necessity of using turpentine or other thinning agents, or such specific gravity-increasing agents as sodium chloride or other salts or chemicals. When considered advisable to employ such agents, the addition of only a minimum proportion thereof is found suflicient for serving their function.

'A further object of the present invention is to provide means for minimizing the loss of turpentine by retaining materials under treatment in a completely enclosed system without the use of the vents generally employed in maintaining atmospheric pressure in the processing equipment. The loss of turpentine is one of the most serious losses occurring in current methods of processing pine oleo-resins. This loss of turpentine ranges from a quart to a gallon per barrel of crude oleo-resin, and is associated to a certain extent with the failure of securing elfective separation of aqueous and oleo-resinous materials. Turpentine and water are miscible in certain proportions at atmospheric pressures and temperatures, and emulsions are formed inwhich turpentine is the dispersed phase. These emulsions are relatively quite stable and are ordinarily discharged as Waste along with dissolved turpentine. In the present process the emulsions of turpentine and water are broken by means of a temperature treatment, and the turpentine, separated as vapor or liquid or both, is recovered before the water is discharged from the system.

Another object of the invention is to providev for improved separation of extraneous solids contained in crude oleo-resin without the use of a filtering medium. Filteringmeans may be employed, if desired, primarily as a precautionary measure toensure against undesirable results from the unusual or accidental, rather than as an essentialin the system. For the purposes of the process, the extraneous solids in crude oleo-resin may be classified as follows:

1) Solids of specific gravity greater than 1.0. These include sand, woodchips in which the cells are filled with water or oleo-resin, andparticles of bark in which the cells'are filled with oleo-resin.

(2) Solids of specific gravity less than 1.0. These include pieces of bark. .and other vegetable tissue in which the cells are sufiiciently filled with ,air or other gas, or vapor to give buoyancy to the particles.

In connection with the present invention it has been foundthatthe buoyancy of particles 'in the second group of the above classification may be readily destroyed by increasing the pressure of the liquid surrounding them so that the liquid enters the cells causing condensation of vapors, or compression of the air or'gas in the cells to a degree that the liquid fills the cells, which results in the sinking of the particles.

The specific gravity of the material comprising the cell walls of vegetable matter in crude oleo-resin, has been found to be substantially 1.50. When the cells become filled with the liquid in which the particles are immersed, the particles sink in view of the high specific gravity of the cell wall material as compared with the liquid. In

the present invention the processing equipment'is preferably kept completely filled with oleo-resin aggregates together with associated water'and extraneous trash, and an effective separation is obtained by controlling the pressure and temperature of the material in the system.

Other objects and advantages of the invention will be apparent in the following detailed description referring to the accompanying drawings, in which:

Fig. 1 is a plan view of a plant for the storage and processing of oleo-resin aggregate;

Figs. 2 and 2A are elevational views including a continuous chain of apparatus shown in Fig. 1;

Fig. 3 is an elevational view, partly in section, of a melter employed in the plant;

' Fig. 4 is a top view of the melter shown in Fig. 3;

Fig. 5 is a section on line 5-5 in Fig. 3 in the direction of the arrows;

Fig. 6 is'a section on line 6-6 in Fig. 3 in the direction of the arrows:

Fig. 7 is a vertical section of a unit in the chain of apparatus employed;

Fig. 8 is a section on line 8-8 of Fig. 7, and Fig. 9 is a section on line 9-9 of Fig. 7, in the direction of the arrows;

Fig. 10 is a vertical section of a still in the chain of apparatus;

Fig. 11 is a section on line 11-11 of Fig. 10 in the direction of the arrows;

Fig. 12 is a section corresponding to the section in Fig. 11, but having certain modifications;

Fig. 13 is a section on line 13-13 and Fig. 14 is a section on line 1414 in Fig. 12 in the direction of the arrows.

The method of operating the plant illustrated will be pointed out in connection with the description of the apparatus. Similar reference characters indicate similar parts throughout the various figures of the drawing.

.A preferred arrangement of apparatus, as substantially shown in Figs. 1, 2 and 2A, comprises one or more melters or chambers for liquefying the gum, connected to a chain of apparatus including a pump 2, a heat exchanger 3, a pressure tank 4 into which liquid is. forced from the heat exchanger 3 under pressure of the pump 2 and in which;

sedimentation of solids occurs, a pressure relief valve 5 for setting the pressure of pumped liquid in tank 4, a

vessel 6 having among other features a flash or low pressure compartment 7, one or more receivers ,or accumulators 8, a still 9, and a combined condenser and receiver unit 10. One or more of these chains may be provided in a plant. In Fig. 1, two such chains A and .A" are shown, each having-two melter units, 1 in order to maintain a continuous flow of material to be processed in each chain. The various units may be of a particular preferredconstruction and may be operated in a preferred manner as described hereinbelow.

The melter chambers 1 are positioned adjacent gum pits 11 into which the oleo-resin collected from pine forests is dumped. The crude pine oleo-resin is transferred from the pits 11 or from storage tanks (not shown) to hoppers 12 by suitable means such as a dredging bucket as described in Patent No. 2,400,040. The hoppers 12 may be steam-jacketed atp13 to facilitate the flow of gum through the valves 14 into the melters 1.

Details of the melters 1 are shown in Figs. 3, 4, 5 and 6. Each melter 1 is connected to a valve 14 by means of a conduit 15 through which the oleo-resin from a hopper 12 flows downwardly and through a side of a melter. The conduit 15 includes an enlarged section 16, the horizontal cross section of which is preferably rectangular and a the lower end of which is connected to an orifice 17 in the melter. Positioned in each corner of the rectangular section 16 is a steam sparger pipe 18 arranged so that there is no interference with the flow of gum through the conduit 15. The steam entering through spargers 18 is controlled by a thermostatically operated valve 19 having operative connection with a thermostat attached to conduit 15 at a suitable location as at 20.

While a melter chamber 1 is being filled, steam is ad mitted through the spargers 18 and also through a valve 21 in a pipe 22 connected to a sump 23 at the bottom of a melter. The steam entering through pipe 22 continues the heating of the gum admitted through the orifice 17, when the entering gum is below a desired working temperature of for instance 212 F. The valve 21 is regulated by thermostatic means including a thermostat element 25 in the head 26 of a melter. A charge is made as quickly as possible and the gum is gradually brought to the desired temperature by the steam entering through the pipe 22. Heat is also applied at the bottom of a melter by means of a jacket 28 annularly disposed about the sump 23, and having a steam pipe connection 29 and a trapped condensation outlet (not shown in the drawings).

Across the top of the sump 23 is a perforated plate 30 which also extends across the largerupper flaring end of a funnel-like element 31. The smaller end .of this element extends downwardly and axially in the sump 23 to a distance short of the bottom of the latter. Steam entering thesump 23 passes upwardly around the funnellike element 31 and through perforations 32 in the upper end thereof. Thus no steam passes through the small lower end of the element 31 but nevertheless reaches the plate 30. When a considerable volume of steam is required the pressure in the sump 23 forces liquid therein upwardly through the lower end of the element 31 into the main space in the melter. During the charging operation, the steam flows at full volume rate through the spargers 1.8 as well as through the valve 21 and upwardly through the perforated plate 30. The melter, while being filled, is vented through a suitable vent opening (not shown) in the head 26. As soonas the melter is filled, the vent is closed and the oleo-resin stops flowing through the conduit 15. This stoppage of flow causes the contents of the conduit to become heated to a temperature at which the valve 19 is automatically closed.

The heating of the charge in the melter is continued by screen 34 (Figs. 3 and 5) spaced from the top of the melter, extends fully across the inside thereof. Encircling the melter at substantially the level of the screen 34 is a conduit 35 for steam or hot water. This conduit is divided by transverse Walls 36 into six substantially equal sections 37. Connected to each section is a steam or hot water supply pipe 38. Each section is connected to theginten'or of the melter by a plurality of orifices 39, at a level slightly below the surface of the screen 34:-

A pair of spaced, solid flanges 40 and 41.extends around the inner wall of the melter near the screen 34, and a similar pair of flanges 42 and 43 is positioned near the bottom of the melter. Extending from the inner edge of flange 40 to the inner edge of flange 41 is a cylindrical screen 44 concentric with respect to the Wall of the melter, providing an annular space 45. A cylindrical screen 46 is similarly placed with respect to the flanges 42 and 43 and the wall of the melter, providing an annular space 47. As shown in Fig. 6, the screen 46 does not extend across the outlet passage 48 to a door 49 through which trash collected in the melter is removed.

A header 50 is connected to the top 26 of the melter, the spaces 45' and 47, and the sump 23 by means of pipe connections 51, 52, 53 and 54 respectively, provided respectively with valves 55, 56, 57 and 58. The header is connected to the pump 2 (Figs. 1 and 2) by means of a pipe 59.

The pump 2 has a variable speed drive and may be set to pump liquid at any desired rate. In the system here described, a suitable rate is for example about 30 gallons per minute. When a melter is initially connected to the pump 2, the liquid is drawn from the top of the melter through the connection 51, and into header 50, valve 55 being open and valves 56, 57 and 58 being closed. This causes liquid in the melter to pass through the horizontal screen 34. In this initial period, the condition of the charge in the melter is substantially as follows. The floating extraneous trash is arranged in a horizontal layer just beneath the screen 34 with the most buoyant pieces in direct contact with the screen and the less buoyant forming a thickened layer of floating material. The extraneous trash of higher specific gravity than the liquid portion of the charge forms a layer that rests on the steam jacketed bottom 60.

The bulk of the liquid portion of a charge in a melter lies between these two layers of trash. Mixed with the liquid oleo-resin are varying amounts of relatively insoluble oleo-resinous material usually of somewhat higher specific gravity than the more liquid portions. These relatively insoluble materials gravitate slowly to the bottom of the melter or when carried upward toward the screen 34 they adhere to the floating trash and are thereby prevented from entering the stream of liquid flowing to the pump 2.

As the pump 2 withdraws material from the melter, a flow of material from the hopper 12 connected thereto is induced in an amount equal in volume to the material being removed by the pump 2. The flow of cold material from the hopper reduces the temperature in conduit 15 below the thermostatically controlled temperature, which results in automatic admission of steam to the spargers 18 through valve 19. The main functions of this steam are to melt completely and to emulsify the gum entering the melter and flowing at a rate .controlled by the pump 2. Steam is alsoadmitted through the plate 30 when the temperature of the outflow from the head 26 falls below the operating temperature, about 212 F. for instance.

Pressure gauges 61 and 62 on the head 26 and just below the screen 34, respectively, indicate the fluid pressure above and below the said screen. During operation of the pump 2, the difierence in pressure shown by these two gauges indicates the resistance to the flow of liquid due to the layer of trash beneath the screen 34. It is desired not to compress this trash layer to such an extent that there is an appreciable pressure drop between the two sides of the screen. When the difierence in pressure reaches an upper limit which is determined from experience in operation, the connection of the pump 2 with the melter is changed from the head 26 to the annular space 45 by closing the valve 55 and opening the valve 56. This relieves the upward pressure on the screen 34 and on the layer of trash beneath it. High velocity jets of hot water and steam are preferably successively or alternately blown through the orifices 39 to break up thecake in the trash layer and to clean the lower surface of the screen 34. After this cleaning operation, the pump 2 is again connected to the head 26. After a period, when the accumulated trash below the screen 34 can no longer be kept sufliciently porous, the pumping is continued from the annular space 45. Still later, the pump connection is changed to the annular space 47 and when this becomes necessary the hopper valve 14 is closed and low pressure steam is admitted in the top of the melter through preferably one section of the conduit 35. Thus only sufiicient pressure is produced in the melter to facilitate the flow of its liquid content to the pump 2 or to a tank (not shown) connected to the sump 23 by a pipe 63 provided with a valve 64.

During substantially the last stage of the melting cycle, the higher gravity, relatively insoluble oleo-resinous materials settle into the sump 23 and displace lower gravity material that has perchance flowed into it prior to closing the valve 14. The displaced material moves upwardly through the orifices 32 and the perforated plate 30. The sump 23 is provided with a sight glass 65 which renders visible any accumulations of the relatively insoluble oleoresinous material. Each time an accumulation of such material is removed from the sump, it is found advan-' tage'ous to admit a small amount of steam through pipe 22 to make certain that the top side of the perforations of plate 30 are not clogged with sediment. After the removal of insoluble oleo-resin material, the pump 2 completes the removal of liquid from the melter through the pipes 54 and 50 by opening valve 58.

During the time that one melter is being emptied, another melter is being filled by opening the valve 14 in theconduit connected thereto. As soon as the first melter is empty, the pump 2 is connected to the second melter and the cycle is repeated.

Solvent, such as turpentine, is admitted in a melter, through a pipe 66 after the oleo-resinous'liquid has been pumped out. The solvent is heated and agitated with the trash by introduction of steam through the pipe 22 and the sump 23. The solvent dissolves the resinous material'- adhering to the trash and the resulting solution is withdrawn through pipe 63 while steam is admitted in the top of the melter through orifices 39. It is preferable to make two extractions with solvent. For instance, the first Wash may be made with turpentine that has been used once in a previous extraction and the second wash is made with fresh turpentine which in the first wash of a succeeding charge. Tanks (not shown) are provided for the various washes. After completion of the extractions, solvent remaining in the melter is removed and recovered by passing steam, admitted through the orifices 39, downwardly through the trash,

through the sump 23, and out through the valve 64 to; a condenser (not shown). into a pit 68 through the door 49.

After the trash is removed, charging of the melter is repeated by opening the hopper valve 14. A supply of crude oleo-resin is maintained in the hoppers .12 to pro vide for continuous flow of the crude to the melters. Charging of the melters is greatly facilitated by exhausting the air therein prior to opening the valve 14 therefor. This can be done by means of a jet exhauster (not shown) or by displacing air with steam passed through the melter. Two melters operating in cycle with each other make it possible to maintain a continuous flow of strained oleo-resin through the pump 2. Also a long period in the time cycle permits of cleaning the extraneous trash and the recovery of the volatile solvent from, the cleaned solid materials. removed from the (not shown).

turn is used for.

The trash is then removed:

The latter are periodically, pit68 by means of a dredging bucket;

.In thecourse of melting crude oleo-re'sin and feeding the liquefied resin from a melter into a chain A or A (Fig. 1), various agents maybe added to the resin 'when and if. desired. A pump 70 with proportioning means and variable speed drive, serves to introduce, by proper adjustment, a desired flow of solvent such as turpentine, or reagent such as acids preferably in aqueous solution into the stream of material maintained by the pump 2. The solventvor agent, if added, may be introduced at any point between the hopper valve 14 and the heat exchanger 3. .When it is desired to thin the crude oleoresin with turpentine or other solvent, the pump 70 is set to deliver such solvent in proportion to the quantity of liquid handled by the pump 2.. It is found advantageous,=for instance, to add turpentine to the stream of crude in the conduit 15, through the pipe 66. In the section 16'the turpentineis' immediately. mixed withthe crude, violentlyagitated by steam from the spargers 18. Alternatively, 'itglS found advantageous to add the solvent to the :melted ,oleo-resin after it has passed through purnpZ. I i-this instance, by proper valve manipulation, the stream from pump2 is conducted into an. agitator '71 where it becomesthoroughly mixed with the agent flowing from pump.70 before the resulting 'mix enters the .heat exchanger 3. Any desired reagent .may be added, by means of flow meters or 'proportioning pumps, to the stream of material maintained by the pump 2. For example, oxalic acid in aqueous solution can be used to convert ferric iron contained in crude oleo-resin into a water-soluble salt so.

that the iron can be removed with the water content of the oleo-resin aggregate.

,As indicated in Fig. 2, the pump .2 operates against a pressure determined by thesetting of the relief valve 5. This, predetermined pressure is maintained to permit heating of .theprocessed materials to elevated temperatures, preferably above the boiling pointv of water, at normal atmospheric pressure, namely, above 212 F. As the temperature is increased, the water and oleo-resin become increasingly incompatible. The surface .tension of water andfoleo-resin, and viscosity of the oleo-resin aggregate are also affected, in that the surface tension and the viscosity are diminished with increase of temperature. The cubical coefficient of expansion of mix-,

tures of rosin and turpentine is greater than that of water. the ten perature is increased there is an increasing difference in specific gravity between water and oleos n-1; e

l -It'is further noted that small particles of cellular extraneous matter present in, the processed liquid at low latter is not materially lowered by the flash boiling of the water.

As will be seen in connection with the operation of apparatus further to be described, the various phenomena noted above are taken advantage of and are involved in the separation of suspended matter and water from oleo-resinous aggregates. With the valve 5 set to maintain a pressure of for instance, 70 pounds per square inch in the system between the pump 2 and valve 5, and with the temperature in heat exchanger 3 at for instance, 284 F, the oleo-resinous stream is passed through the heat exchanger into the bottom of the pressure tank 4. The tank 4 is provided with a steam jacket 72 whichis maintained at the same temperature as the heat exchanger 3. This heating is done in such a manner that convection currents are prevented while the liquid flows through the tank 4. Insulation, substituted for the steam jacket 72, serves also to a sufficient extent pressure are caused-to sink when the pressure, of the liquid in which the particles are suspended is increased. The

rate ofsinking or settlingyis also increased by thedecrease in viscosity-with increasein temperature. Also, it is notedtthat when at an increased pressure a miittureof water and oleo-re sin is heated appreciably above its boilingpointand is then permitted to enter a region of lower pressure, a flash boiling activity occurs. The heat lost incident to such boiling comeslargely from the water in the: mixture. The boiling action breaks any emulsion of water and oleo-resin and the water quickly forms into large drops or globules until a surface equilibrium of the drops of water withtvaporfrom the surface of the drops is-reached. Thehigh latent heat of water causes a slow rate ofevaporation from-the surface of the drops while the low thermal conductivity of liquid oleo-resin also contributes to'the establishment of this equilibrium which results ihthe retention of drops of water in a liquid of inuchzhigher temperature than the boiling point of water.

Theidensity of Water at 212 Ffis 0.958, and at 284 F( appreciable increase inthe density of the oleo-resino'us materials,'-due to the fact that the temperature of the to prevent and to materially reduce convection currents, r

and to maintain the temperature in the tank substantially uniform from the bottom to the top thereof. The cross sectionalrarea of tank 4 serves to limit the vertical velocity of the liquid passing through it. For example, witha tankhaving a cross sectional area of 4,071 square inches (72 inches in diameter), and with the pump 2 pumping at the rate of 30 gallons per minute, the vertical velocity of the stream in tank 4 is substantially 1.7 inches per minute. In any case, the velocity in tank 4 should be sufficiently slow to permit effective sedimentation of suspensions having a higher specific a gravity than the oleo-resin aggregate. The liquid in tank 4. normally contains finely divided solids that pass through the screening means in the melters 1.

The tank 4 has a cylindrical outlet chamber or sump 74 extending from the bottom thereof, and a cylindrical head chamber 75 extending upwardly from the top thereof. The sump 74 and the head 75 each has an outlet 76 and 77 and a sight glass 78 and 79 respectively. Extraneous matter, such as particles of trash and water, collects either in sump 74 or in the head 75 and can be readily expelled by the pressure in the tank 4 upon opening either valve 80 or 81. An outlet pipe 82 connects the head 75 to the relief valve 5, and a screen 83 is positioned across the entrance to said pipe 82 for passage of clarified liquid under pressure of the pump.

As above indicated, the extraneous trash with its cells filled with vapor or air as, a result of the. treatment in a melter 1, is subjected to pressure exerted by the pump 2 and the liquid is forced into the cells. The buoyancy of a trash particle is thus materially decreased and as the stream from pump 2 enters the tank 4, the particle sinks. Particles that sink are removed from the sump 74,'and particles that are carried upward are removed from the head 75.

The streampassing through the relief valve5 is conducted into the flash compartment 7 of the vessel 6 (Fig. 2A). Referring to Figs. 7, 8 and 9 whichillus trate the details of vessel, 6, oleo-resin containing water is conveyed in a stream through pipe 35 into the flash compartment 7 which is in the uppermost zone of a cylindrical vessel 86. In the bottom 87 of the compartment 7 is a central depressed or cup-like portion 88 through which a tube 89 passes that is supported vertically by supports 90. The upper end 91 of the tube 89 flares outwardly and serves as a weir. The lower end of tube 89 is positioned near the bottom of the lower zone or compartment 92 of the vessel 86. Small openings 93 are provided in the tube 89 at a level within the cup 88 to permit continuous seepage of liquid into preferably the lowermost part of the zone 92.

The mixture of oleo-resin and water previously sub jected to the aforementioned elevated pressure and tem: perature enters the flash compartment 7 which ismaintained at a considerably lower pressure, as for example, substantially atmospheric. The unvaporized liquids col,

9 lect in the bottom of compartment '7, and after the. flash boiling the'temperature of the water has lowered to such an extent that its specific gravity has risen substantially so that it settles out of the mixture relatively quickly. A substantial proportion of the water settles into the cup 88, passes through the openings 93, and is conducted through the tube 89 to the lower level of zone 92. Overflow liquid from compartment 7 passes intto the tube through the upper end 91. Vapors from compartment 7 pass upwardly through an opening 94 above which is a deflecting baflie 95. Above this baflie is a refluxcondenser 96. Condensates pass from the annular space around the opening 94 downwardly through a pipe 97 and into the lower level of zone 92. v

The water, which at 212 F. has a specific gravity of 0.958 as contrasted to 0.926 at 284 F., continues to settle to the bottom of zone 92, while the oleo-resin having a specific gravity of substantially 0.932 at 284 F. (with 28 pounds rosin to a gallon of turpentine) rises and flows upwardly to outlets 98. A 'heating jacket 99 around a substantial part of the zone 92 ensures against conv'ectional currents by uniformly heating the liquid in this zone and particularly the upper levels of this liquid. The heat so applied maintains the temperature of the oleo-resin so that its specific gravity remains low with respect to the specific gravity of the water in the lower portion of the zone 92. The water may be withdrawn at selected intervals through the outlet pipe 100 provided with a sight glass 191.

The zone or compartment 92 has two outlets 98. for liquid oleo-resin aggregate from which water has been removed. Each outlet is connected by a pipe 102, havinv a valve 103, to a pipe 104 which extends with its open end to a level close to the bottom of an accumulator 8. With two such accumulators 8 in each chain A and A, a constant or continuous flow of liquid oleo-resin to the stills 9 through a pipe system 105 (Figs. 1 and 2A) is maintainable. I

A sump 106 is provided for each accumulator 8, into which waterthat is ,not removedin vessel 6 settles and is withdrawn through a pipe 107' having a valve 108. The piping 105 extends to the bottom of the sump 106 andis connected to the pipe 107. The piping 105 is also connected directly to an accumulator 8 adjacent the bottom thereof by a pipe 110 with a valve 111, and can thus serve substantially as a means for the continuation of the flow from pipe 104. V

Y The head 112 of each accumulator 8 is connected by a piping 113 to the vapor space of the reflux condenser 96 to serve as a pressure equalizer.

The still 9, in each of the chains A and A, is a batch vacuum steam still which is highly satisfactory for distillation of oleo-resins to obtain rosin and turpentine. A vacuum pump (not shown) is connected to the vapor space of a condenser 114 in unitby means of a pipe 115. The reduced pressure in the still 9 causes the oleo-. resin to flow through the piping 105 from the -accumulators into a heat exchanger 116 and thence 'into the still 9. The heat exchanger ensures maintenance of the feed at a predetermined temperature as for instance, 300 F. Suitable means such as thermostats may be employed tocontrol the steamsupply to provide the desired tempera, ture. a 7 'Figs, 10-14 may be referred to for details ofthe still 9. The still is divided into two sections 118 and 119 by a flash plate 120. A manhole 121 with a cover 122 is provided in the center of the flash plate, and bubble caps 123 are distributed in the annular portion of the plate. A channel 124 extends radially across the annular space from the manhole 121 to the outer wall of the still. The wall 125 of the channel has its upper edge at a higher level than the upper edge of the wall 126 so that the wall 126 serves as a weir and heatedliquid oleo-resin entering the still through a pipe 127 from the heat exchanger 116 flowsclockwise in the annular space aroundthe manhole and over the weir 126 into the channel 124.- The ole'd; resin from the channel enters the lower section 1190f the still through a seal pipe 128. The level of the-oleoresin on the plate, is determined by the weir 126. Suitable perforations, generally referred to as weep holes (not shown), are provided in flash plate 120 so that it will not retain liquid thereon after the flow to the still is stopped.

A flash plate 130 without bubble caps may be used in place of plate 120 as illustrated in Figs. 12,13 and 14. A channel 131 formed by walls 132 and 133 in the manner as shown in the case of channel 124, causes the heated liquid oleo-resin entering through a feed pipe 134 to flow around an uncovered manhole 135 and over the wall 133 into the channel 131. The liquid in this channel flows downwardly through an opening 136 into an annular space 137 formed by a cylindrical screen'138 in alignment with the manhole 135, and an outer cylindrical wall 138' extending down from the flash plate 130. The bottom wall 139 of the annular space 137 is providedwith perforations 140. Some of the liquid in the space 137 runs down through these perforations into the lower section 119 of the still, but a major portion of the liquid flows through the screen 138 and thence into the section 119.

The section 119 of the still 9 is provided with closed steam coils 141 and an open steam sparger 142. After the sparging steam passes through a batch of oleo-resin collected in the bottom of the still, the steam rises and passes through the bubble caps 123 of the flash plate 120 shown in Figs. 10 and 11. In the use of the plate arrangement shown in Figs. 12, 13 and 14, the oleo-resin flowing through the screen or perforated plate 138 is contacted by the sparge steam moving upwardly through the manhole 135.

A flash plate is highly desirable for distillation of oleoresins since it secures economy and saves time in the steam-stripping of terpenes from resin acids. One of the most undesirable defects in gum rosins is low melting points caused by inadequate stripping of higher boiling terpene oils from the rosins.

Vapors of terpenes and water pass upwardly through the dome of the still 9, then through a conduit 144 and a foam separator 145 into the condenser and receiver unit 10. The receiver 146 of this unit is positioned beneath the condenser 114 which refluxes distillates into the receiver. The distillates are passed through a sight glass vessel 147 into a tank 148. An open pipe 149 passing through the bottom 150 of the receiver to an upper level in the tank 148 serves to equalize the pressure between the receiver and this tank.

Abatch distillation operation is completed by discon tinuing the flow of oleo-resin to the still; by continuing the flow of open steam through the sparger 142; and by sampling the distillate by closing a valve 152 in the pipe glass vessel 147 until the latter is leading to the sight filled to the glass level. The valve 153 is then closed,- and the distillate in the sight glass vessel 147 is permitted to separate into a Water layer and a turpentine layer, the turpentine layer being visible. The thickness of the turpentine layer indicates the degree to which the volatile oils have been removed from the batch in the still. While the sampling is in progress, the pipe 149 serves as an overflow means. i

The tank 148 is connected to a tank 155 by a pipe-156- provided with a valve 157. Upon opening the valve 157,

the distillate flows from tank 148 into tank 155. The

tops of these tanks are connected by a pipe 158 having a valve 159. The pressure in these tanks is equalized by opening the valve 159. While the tank 155 is being emptied, tank 148 is disconnected from tank 155 by closing the valve 157. A complete disconnection is eifected by also closing valve 159.

In connection with the present process it should be noted that the variability of crude exudates from pine genome trees is so great that a process for purifying oleo resins obtained'therefrom must be sufficientlyflexible topermit variations in the process to cope with the treatments needed :due to variations in the crudes. The seasonal variations in the crudes, as between those collected in thespring months and those collected in the fall and Winter months, include variations of the ratio of resin acids to turpentine content of the oleo-resins, and variations in the proportions of oxidized materials present in the crudes. The ratio of resin acids to turpentine vary from pounds of resin acids to one gallon of turpentine in the spring and early summer months, to 40 pounds resin acids in a gallon of turpentine in the fall months. For the entire producing season the average ratio is 28 pounds of resin acids to a gallon of turpentine. lt has been found in thisprocess that the ratio of these constituents is a convenient means of defining a crude olco-resin with reference to its processing.

The following tabulation shows the variation in the specific gravity of mixtures of resin acids and gum turpentine at the temperatures selected for purposes of illustration Specific Gravity Percent Ga1s./ Ratio Units Tur- Unit at pentine 70 F. 212 F. 284 F. 212 F.

25 lbs. 110511111 g. 22. 3 1. 015 0. 903 0. 030 4.07 28 lbs. .Rosinzl g. T 20. 4 1. 020 0. 972 0. 933 4. lbs. Rosiml g. '1 15. 2 1.033 0.981 0. 952 s. 16.8 lbs. Rosiml g. '1 30.0 1.000 0. 945 0. s 3. 04 13.41bs. Rosinzl g. 35.0 0. 900 0. 934 0.893 2.83

The values in the last two lines of the above tabulation illustrate the results obtained by thinning with turpentine to lower the specific gravity of natural aggregates. Converting the 25 lb. rosin unit to the 13.4 lb. rosin unit it is necessary to have a turpentine content in the 25 lb. unit of or 1.865 gallons. This requires an addition of .865 gallon of turpentine to the 4.07 gallons in the 25 lb. unit. If the pump .2 in the above-described apparatus is set to deliver 30 gallons pcr minute then pump 70 is set to deliver or about 6.4 gallons of turpentine per minute to the stream of. liquid emerging from the pump 2.

The above calculation applies. when the turpentine is added on the pressure side of the pump. 27. When the turpentine for thinning is introduced into the charging conduit 15 of the melter 1, the pump 2 handles the thinned units (in the above table) of 2.83 gallons per unit, for

When it is desirable to maintain constant the rosin content of the liquid passing through pump 2, its capacity is increased to 36.4 gallons per minute and pump 70 delivers 6.4 gallons of turpentine per minute to'the conduit 15. This is a preferred adjustment.

k The specific gravity of water at 212 ,F; and 284 F. is respectively 0958 and 0.926. It is seen from the above tabulation 'that by using atemperature of 284 F. C.) for instance, in tank 4 and causing the liquid delivered 'to'compartment 7 to flash boil, it is possible to separate water elfectively in compartment 92 from all of the natural oleo-resinous aggregates except types collected in the fall months (usually called scrape), in which case suitable thinning may be resorted to.

The increasing use of sulfuric acid as a stimulant for the production of oleo-resin by trees brings in another variable with respect to crudes. This requires more effective washing of crude oleo-resins than has heretofore been considered necessary. Such washing requires larger quantities of water than those contemplated in the process of Patent No. 2,140,514. When water is used in relatively large amounts, it is preferable to thin crude oleo-resin with turpentine to an extent that water separates freely from the aggregate in tank 4 from which it can be withdrawn continuously through valve 80. The pump 70 can be used for adding turpentine for thinning as described above, and an additional pump or flow meter (not shown) is used to introduce the desired amount of water into the agitator 71. his generally preferable in such cases to introduce,

the turpentine for thinning into the melter 1.

Upon withdrawing excess water from tank 4 through valve 80, the water remaining in the aggregate passing through the relief valve 5 is to a large extent in the dispersed phase of the relatively stable emulsions that have been described in Patent No. 2,140,514.

A specific example of processing oleo-resinous exudates of pine trees in accordance with the present invention is given below as an illustration: i

Crude oleo-resin flows from a hopper 12 into a chamher 1 through a conduit 15 wherein melting and emulsification are initiated and effected. Relatively insoluble or infusible resinous matter settles to the bottom of the chamber 1 or adheres to floating trash under the screen 34. A partially purified liquid oleo-resin is withdrawn from the chamber 1 through 34, 44 and 46 selectively or in any suitable order, by pump 2. The liquid stream from pump 2 is under pressure determined by the setting ofrelief valve 5 which serves as a pressure regulator. The pressure is,'for example, 70 pounds per square inch on the liquid between pump 2 and valve 5. The increased pressure forces some liquid into the cellular structure of small pieces of extraneous trash that incidentally flow along in the liq'uid stream from the chamber 1. The stream passes through the heat exchanger 3 where it is heated to 284 F.', for example, whereby the specific gravity and viscosity of the elecresinous material are lowered. The oleo-resinous material maintained at this temperature and the above pressure moves slowly upwardly through the'tank 4, wherein the particles of trash settle to the bottom, and thence through the valve 5. The pressure on the liquid is suddenly released and drops substantially to, for example, atmospheric pressure. Flash boiling results and a surface equilibrium is reached between the water and oleo-resin,

and drops of the water at 212 F. are formed in the liquid .oleo-resin which is at substantially 284 F. The specific gravity of the water materially increases, and therefore an increase in the disparity in the specific gravities'between liquid water and liquid oleo-resin results which causes the water to separate more rapidly from the lower gravity oleo-resin. The oleo-resin stream, substantially free from solid particles of extraneous trash andaque'ous matter, then moves to the still 9. After removing terpenes, rosin remaining in the still is dropped mto a rosin receiver 161. The receiver 161 is preferably r a blow case from which the rosin is transferred to tank cars,' drums or other containers by means of compressed air.

The steps employed in the above example are highly effective in the processing of oleo-resins with or without the use of materials to modify, or, raise or lower, the

' of extraneous trash from oleo-resin, or it may include under other conditions the removalof aqueous liquid, preceded by liquefaction orfollowed by distillation or. both.

Up to the time of this invention it has been the practice to process oleo-resins at atmospheric pressure, the pressure being maintained by open vents connected with condensers. Air moves in and out through these vents as tanks are emptied and filled, and overheating of the mixtures of water and oleo-resin sometimes results in violent boiling as .the mixtures are released. Such conditions result in unnecessary agitation in settling tanks as well as unnecessary losses of turpentine. In the present inventionno vents are employed between the hopper 12 and the still 9, and instead, receivers 8, for example, are connected to eachother for pressure equalization. An entire system can be 'kept closed to form a single expansion chamber. The various apparatus units serve, in efiect, primarily as zones in a continuous system for conducting steps in the process. The outflow of material from the receivers to the stills can be made to equal substantially the inflow from the vessel 6, so that there is not much, or minimum, fluctuation in pressure. This so-called system or expansion chamber is protected against undesirable pressures by means of low pressure relief valves.

For controlling temperatures and pressures throughout the system suitable instruments including thermometers, pressure meters and thermostats are properly placed for determining temperatures and pressures in each step. Thermostatic control, for example, is employed for heatexchanger 3 as well as for heat exchanger 116.

Though specific temperatures and pressures have been mentioned hereinabove for purposes of illustration, in

view of the nature of the material treated, and particularly in view of its variableness, these temperatures and pressures may vary over wide ranges. The temperatures and pressures employed in the oleo-resinous stream passing from the melting chamber to the still are adjustable and depend on the composition of this stream and on other factors. The temperature, for instance, to which the stream is heated in the heat exchanger 3 and tank 4, the pressure therein, and the subsequent reduced pressure in the vessel 6, are in general, such as to provide an appreciable increase in the speed of separation of solid and liquid suspended impurities. The rate of flow of the stream can be adjusted in accordance with the apparatus employed and the speed at which the impurities settle out in the liquid. Preferred temperatures and pressures in the stage in which the suspended solid impurities are separated from the oleo-resin aggregate may be such that the liquid is at a temperature above the normal boiling temperature of water and below the ebullition temperature of oleo-resin constituents or of the mixture, at the raised pressure employed. Overheating is avoided to prevent detrimental chemical change, and throughout the processing up to the distillation stage, the bulk of the oleo-resin aggregate remains in the liquid state. The higher pres sure in the stage in which the solid impurities are removed is such that all the normally liquid constituents remain in the liquid phase and the oleo-resins remain substantially unchanged in chemical composition. In'the water-removal stage at the lower pressure, which may under certain conditions be above, below, or at atmospheric pressure, no complete vaporization of the Water content takes place.

The pressure-drop is efie'cted primarily to obtain a wideneddiflerencebetween the specific gravity of the oleo-resins and the specific gravity of the water, while maintaining the major portion of each in a given processed oleo-resin mixture in liquid form, so that the water will more readily separate from the oleo-resins. 4

What is claimed is:

1. A process of treating oleo-resins containing a dispersed aqueous phase to separate water therefrom, the said process comprising while continuously passing liquid oleo-resin containing water dispersed therein through a closed system having a superatmospheric pressure zone and a decreased pressure zoneheating the liquid oleoresin and water mixture below ebullition temperature of said mixture and passing said heated mixture from said pressure zone into the decreased pressure zone and removing separated water in liquid form from the said decreased pressure zone. Y V

2. A process of treating oleo-resins containing a-dispersed aqueous phase to separate water therefrom, the said process comprising submitting a liquid oleo-resin and water mixture to superatmospheric pressure at atemperature above the normal boiling point of water and below the ebullition temperature of said mixture at said superatmospheric pressure, suddenly releasing the pressure to cause sudden momentary boiling and partial vaporization of the water thereby lowering the temperature of the water to obtain an increase in disparity in the specific gravities between the liquid water and oleoresin, and separating from said cleo-resin the liquid water that settles out of said mixture.

3. In a process of purifying crude oleo-resins, heating crude pine oleo-resin containing water and suspended solid impurities in a melting zone to liquefy said oleoresin, continuously passing the heated liquefied crude pine oleo-resin from said melting zone into an enclosed superatmospheric pressure zone while removing at least a portion of the suspended solids from said resin, heating the resulting mixture containing oleo-resin, dispersed water, and suspended extraneous solid particles in said pressure zone to a temperature above the normal boiling temperature of water and below the ebullition temperature of said mixture while subjecting the suspended extraneous solid particles in said mixture to gravity sedimentation to obtain a water and .oleo-resin mixture relatively free from suspended extraneous solids, continuously passing the resulting water and oleo-resin mixture from'said superatmospheric pressure zone into a decreased pressure zone to cause sudden momentary boiling and partial vaporization of the water, thereby lowering the temperature of the water to obtain an increase in disparity in the specific gravities between the liquid water and oleoresin, and continuously passing the oleo-resin through said decreased pressure zone at a rate to permit settling out of liquid water in said latter zone.

4. In a method of operating a system for the purification of crude oleo-resinous material, passing liquefied oleo-resin aggregate containing suspended extraneous solid particles and water through a uniformly heated sedimenration zone under superatmospheric pressure in said system, heating said aggregate in said sedimentation zone to a temperature above the boiling point of water at atmospheric pressure but below the ebullition temperature of the aggregate at said superatmospheric pressure while permitting said solid particles to separate from said aggregate, passing liquid oleo-resin aggregate containing water from said sedimentation zone into a decreased pressure zone and permitting the water in said aggregate to separate in said decreased pressure zone in liquid form, the said system being closed to prevent escape of vapors of oleo-resinous matter to the atmosphere.

5. In a method of operating a system for the purification of crude oleo-resinous material, heating liquid oleoresin aggregate containing water under superatmospheric pressure at a temperature above the normal boiling tem- "15 perature of water butbelow theeb'ullition temperatureof the aggregate at said superatmospheric pressure, and reducing the pressure on said aggregate while permitting water'to'settle out in liquid form in said system, the said system being closed to prevent escape of vapors of oleoresinous matter to the atmosphere.

6. In a method of operating a system'for the purification of crude oleo-resinous material, passing crude oleoresinous material containing suspended extraneous solids and water into a melting zone in said system and heating the material to liquefy the oleo-resin aggregate therein, passing liquefied oleo-resin aggregate containing suspended extraneous solid particles and water from said melting zone through a uniformly heated sedimentation zone under superatmospheric pressure in said system, heating said aggregate insaid sedimentation zone to a temperature above the boiling point of waterat atmosphericpressure but below the ebullition temperature of the aggregate at said superatmospheric pressure while permitting said solid particles to separate from said aggregate, passing liquid oleo-resin aggregate containing water from said sedimentation zone into a decreased pressure zone and permitting the water in said aggregate to separate in said decreased pressure zone in liquid form, the said system being closed to prevent escape of vapors of oleo-resinous matter to the atmosphere, and passing the resulting oleo-resin aggregate continuously from said system into a distillation zone for separation into rosin and turpentine.

7. In a process of purifying crude oleo-resins, mixing oleo-resin aggregate containing combined iron with an aqueous solution of a reagent for converting the combined iron into a water soluble iron compound, heating the resulting mixture of oleo-resin aggregate containing an aqueous solution of said iron compound under superatmospheric pressure to a temperature above the normal boiling 'point of water but below the ebullition'temperature of the oleo-resin aggregate, and releasing the pressure on the said mixture andseparating iron-containing aqueous matter in liquid form from the said mixture.

8. In a method of operating a system for thepurification of crude oleo resinous material, injectinga mixture containing oleo-resin and water dispersed thereinat a temperature of substantially the boiling point of water but below the boiling temperature of the mixture into a low-pressure atmosphere to flash-boil the water while maintaining the oleo-resin in a heated liquid state, thereby effecting a decrease in the temperature of the water with a resulting increase in its specific gravity and separation thereof in liquid form in the body of the oleo-resin fluid, maintaining the oleo-resin hot with a consequent relatively lowered specific gravity and maintaining the result ing fluid body'unagitated toeffect settlingout of the water from'the said oleo-resin. I

References Cited in the file of'this patent UNITED STATES PATENTS OTHER REFERENCES Lawrencez'Industrial and'Engineering Chem vol. 34,

Claims (1)

1. A PROCESS OF TREATING OLEO-RESINS CONTAINING A DISPERSED AQUEOUS PHASE TO SEPARATE WATER THEREFROM, THE SAID PROCESS COMPRISING WHILE CONYINUOUSLY PASSING LIQUID OLEO-RESIN CONTAINING WATER DISPERSED THEREIN THROGH A CLOSED SYSTEM HAVING A SUPERATMOSPHERIC PRESSURE ZONE AND A DECREASED PRESSURE ZONE HEATING THE LIQUID OLEORESIN AND WATER MIXTURE BELOW ELBULLITION TEMPERATURE OF SAID MIXTURE AND PASSING SAID HEATED MIXTURE FROM SAID PRESSURE ZONE INTO THE DECREASED PRESSURE ZONE AND REMOVING SEPARATED WATER IN LIQUID FROM FROM THE SAID DECREASED PRESSURE ZONE.

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