US3272207A

US3272207A - Tobacco moistening

Info

Publication number: US3272207A
Application number: US343090A
Authority: US
Inventors: Frank B Doyle
Original assignee: Individual
Current assignee: Individual
Priority date: 1964-02-06
Filing date: 1964-02-06
Publication date: 1966-09-13
Anticipated expiration: 1983-09-13

Description

Sept. 13, 1966 F. B. DOYLE TOBACCO MOISTENING Filed Feb. 6, 1964 Inventor FRANK B. DOYLE 85/ y rlgz, m't'fi fH-ko (11.215 6 WATER TEMP. IH PAN \08 0F F\G.|.

United States Patent 3,272,207 TOBACCQ MOISTENING Frank B. Doyle, R0. Box 237, Raymond, Ill. Filed Feb. 6, 1964, Ser. No. 343,090 7 Claims. (Cl. 131-133) The present invention relates to an improved process and apparatus for conditioning organic products in bulk and, more particularly, it relates to a process and appa ratus for conditioning tobacco.

Tobacco generally is stored for lengthy periods between the time that it is harvested from the fields and the time that it is used. When tobacco is stored for such periods, moisture is dissipated from the leaves and the product becomes dry and brittle. It, therefore, is necessary to condition the product prior to use. In moistening bulk products, such as tobacco, the material generally is placed in a hermetically sealed chamber from which air is drawn. Steam then is introduced to the chamber, the chamber again evacuated and steamed a second time to increase the probability of even distribution of moisture throughout the body of tobacco. The above steps may, of course, be repeated until a satisfactory product is realized. It should be noted, however, that economical processing must be realized in order to provide a product that will be competitive and to that extent moistening in optimum time is desired.

The method and apparatus set forth herein include means set forth in my Patents 2,832,353 and 2,997,046, relating to equipment for moistening materials in bulk.

A frequent problem encountered in the conditioning or moistening of tobacco products in bulk is that cold spots occur Within the body of tobacco. These cold spots are defined by areas of tobacco that have not been moistened and warmed during the steaming portion of the conditioning cycle. One cause of such cold spots is that all of the residual air or non-condensible gases may not be removed from the hogshead of tobacco and pockets form to block movement of the steam front uniformly over the entire tobacco surface. Repeated cycling, i.e. evacuation and steaming, will improve the uniformity of the treated tobacco product, but frequently cold spots will still occur.

The apparatus and method as set forth here-in do not introduce steam directly into the chamber. The steam, instead, is passed into the condenser, through the first stage ejector, and then into the conditioning chamber. By this method steam of the proper quality is supplied to the chamber Without the need of supplementary moistening devices as required on conditioning apparatus in conventional conditioning processes. It has been found that the condenser and ejector absorb a sufficient quantity of heat from the steam to render it suitable for conditioning the tobacco. It is important, however, that the air-vapor mixture in the condenser be controlled carefully during evacuation of the chamber and of the condenser during initial evacuation thereof to assure that non-condensible gases are exhausted to atmosphere and do not remain in the chamber or condenser for introduction to the tobacco during the steaming portion of the conditioning cycle.

In the vacuum process for conditioning tobacco, or other organic material to add moisture thereto, it first is necessary to evacuate the conditioning chamber to a suffici'ently low absolute pressure so that moisture will be evaporated from the material. Vapor continues to be discharged from the material due to the fact that water molecules are continuously being withdrawn from the chamber are-a and it is the natural characteristic of any fluid to reach equilibrium condition in its local area. To this extent evaporation will continue and will serve to remove or scrub out the residual air or non-condensible gases from the inter-cellular spaces of the hygroscopic materials so that when water vapor is admitted to the conditioning chamber during the steaming portion of the conditioning cycle, the vapor Will readily penetrate all of the fibers of the material, condense upon the relatively cooler surfaces and add the desired moisture to the material.

It should be observed that when the outside temperature at the tobacco conditioning installation is relatively low the initial evacuation period required to evacuate the conditioning chamber and the condenser must be lengthened relative to the evacuation period during elevated ambient temperature conditions to reduce the absolute pressure in the conditioning chamber to the point where the vapor in the tobacco, or other material, begins to be expelled from the material. During these colder conditions, the cooling water supplied to the condenser of the system is relatively cold and if the system, for example, is adjusted to admit the larger amount of cooling water required during elevated thermal conditions then the condenser Will be at too low a temperature for optimum processing. The increased evacuation time during initial cycling with low ambient temperate conditions is essential to assure removal of air from both of the chamber and the condenser space. Further, the cold condenser Water introduced during the low outside temperature conditions introduces little water vapor to the condenser space.

The present invention is directed to the provision of an improved process and apparatus wherein the non-condensible gases are removed from the system during conditioning. The process and apparatus of the present invention contemplate the use of means to control the airvapor mixture Within the condenser, to assure proper preparation of the condenser for the steaming portion of the cycle and thereby to provide a system that will not result in reintroduction of non-condensible gases to the conditioning chamber during the steaming portion of the conditioning cycle. The invention is specifically directed to the provision of means to control the absolute pressure (or temperature, which is a function of the pressure) in the condenser. It should be observed that if the non-condensible gases are not removed from the conditioning chamber during initial evacuation, or if non-condensible gases are introduced during steaming, said noncondensibles will enter the body of material being conditioned along with the steam and will define a block to prevent the entry of steamto the gas occupied portion of the tobacco or material with the result that a cold spot (unconditioned area) will be formed due to failure of the steam to reach the area to moisten and Warm the body of tobacco. These cold spots are highly objectionable in a conditioned product and may result in partial product loss upon subsequent processing of the conditioned tobacco, or other material.

It, therefore, is a general object of the present invention to provide an improved method and apparatus for conditioning tobacco.

Another object of the present invention resides in the provision of an improved method for conditioning tobacco wherein steam for conditioning said tobacco is introduced to the conditioning chamber through a condenser.

A further object of the present invention resides in the provision of an improved method for condtioning tobacco that eliminates cold spots in the conditioned tobacco regardless of ambient conditions under Which the method is performed.

An additional object of the present invention resides in the provision of an improved tobacco moistening apparatus having means to control the character of the air-vapor mixture within the condenser during the conditioning cycle.

A further object of the present invention resides in the provision of an improved apparatus for moistening tobacco having means continuously to control the vapor condition within the condenser above the dead end level of the condenser ejector to assure discharge of non-condensible gases to atmosphere.

Another object of the present invention resides in the provision of an improved method for conditioning tobacco wherein the body of tobacco is uniformly moistened and warmed by steam of proper character and condition, the steam passing through the condenser and first stage ejector path prior to injection into the conditioning chamber.

A further object of the present invention resides in the provision of an improved method for conditioning tobacco that is economical to use, that provides uniform conditioning of tobacco regardless of ambient conditions in which the process is conducted and that is readily adapted for use with present conditioning equipment of the type set forth herein.

An additional object of the present invention resides in the provision of an improved apparatus for conditioning tobacco that is easy to install in present conditioning apparatus, that is economical to install and use, that is durable in continued use, that is adapted to close conditioning control during processing, that will provide a uniform conditioned product in use, that will assure uniform conditioning of the tobacco free from cold spots and in optimum processing times.

The novel features which are believed to be characteristic of my invention are set forth with particularity in the appended claims. The invention itself, however, together with further objects and advantages thereof, will best be understood by reference to the following description taken in conjunction with the accompanying drawings, in which:

FIGURE 1 is an elevation view, with parts broken away, of tobacco moistening means for conditioning said tobacco in the manner set forth herein; and

FIGURE 2 is a graphic illustration of the control and sequencing of the conditioning method.

As seen in FIGURE 1, tobacco moistening equipment of the type that may be employed in carrying out conditioning of the tobacco product in accord with the present invention includes a hermetically sealed chamber, illustrated generally at 10. The chamber may be adapted to receive one or more hogsheads of tobacco, indicated at 12, depending upon the requirements of the user. The chamber 10 includes

removable doors

14 and 16 at either end thereof securely fastened to the body of said chamber during the conditioning process, said doors defining means for insertion and removal of the tobacco. Chamber 10 includes a ceiling 18 and floor 20. The ceiling or top 18 is provided with an opening 22 through which the chamber can be evacuated and through which steam is introduced.

A conduit 24 is connected to the opening 22 of chamber 10 in air-tight relation therewith and extends continuously between the chamber 10 and the low pressure side 30 of the evacuating means 32 (described in detail hereinbelow) for the conditioning chamber. A conduit 26, communicating with the atmosphere, is connected to the pipe 24 and chamber 10. The pipe 26 is provided with a valve 28 which, when opened, serves to break the vacuum in chamber 10 and to connect chamber 10 to atmosphere.

As noted above, the low pressure side 30 f the chamber evacuator or steam ejector 32 is connected to the chamber through conduit 24. The first stage or chamber ejector 32 preferably is of the type disclosed in my Patent 2,997,046, wherein the throat area 34 of said ejector is at least .05 square inch per cubic foot of volume of the conditioning chamber. Other dimensions and variations are set forth in detail in said patent. The discharge side 36 of the evacuator 32 is connected to the condenser 38.

A steam supply source 40 is provided for the improved process and apparatus of the present invention. Thelow pressure side 30 of evacuator or steam ejector 32 is connected to the steam source 40 through flow control valve 42 and conduit 44. When the valve 42 is opened steam is introduced to the evacuator 32, passes through the throat 34 and through the discharge 36 to condenser 38. When steam is introduced through the nozzle 46 of the evacuator 32, a lower pressure area is established, as indicated generally at 47, to draw non-condensible gases from the conditioning chamber 10 thereby lowering the pressure in said chamber. Preferably evacuation of the chamber 10 is continued until vaporization of moisture occurs from the tobacco product to be conditioned. This vaporization will assist in removal of non-condensible gases from the body of tobacco and will help to prepare the product for optimum conditioning during the steaming portion of the cycle.

The second stage, condenser ejector or evacuator 48 is defined by a low pressure side 50, a reduced throat area 52 and a discharge side 54. The low pressure side 50 of ejector 48 is connected to the condenser 38 through the conduit 56. The discharge side 54 of ejector 48 exhausts to atmosphere through valve 58. The valve 58 is operable to open or closed position by an air cylinder valve operator 60.

The low pressure side of ejector 58 is connected through the valve 62 and conduit 64 to the steam source 40. When the valve 62 is opened steam is introduced into the low pressure side 50 of the ejector 48 through the nozzle 51 creating a lowered pressure in area 53 to evacuate the condenser 38 through said ejector. During evacuation of the chamber 10 and condenser 38 the valve 58 is in open position to permit discharge of steam and non-condensible gases to atmosphere.

The condenser 38 is connected to the cooling water supply 66 through conduit 68, safety shut-off valve 70 and automatic fiow control valve 72. The cooling water from supply 66 flows into the condenser to distributor plate 74 to provide water dispersion in a manner most effective to assure full interchange of the vapors in the condenser with the cooled water. The condensed fluids collect at the bottom of the condenser 38. A fluid pump 76, driven by an electric motor 78, pumps the condensed fluids back to the cooling tower 66 through conduit for recirculation after cooling in the tower 66. Pump 82 may be employed to aid the pumping action. The pump 82 is driven by electric motor 84. When motor 78 is not operating during the cycle the water circulates through conduit 68, conduit 86, flow controller 88, pump 82 and conduit 80 to reduce the temperature of the water in the cooling tower 66. A check valve 77 is provided in conduit 80 to prevent back flow of fluid toward pump 76.

Steam may be introduced to the condenser by closing valve 58 causing a back flow into the condenser from supply 40. The steam is introduced to the condenser prior to introduction to the conditioning chamber 10 for moistening and warming of the tobacco. In view of the nature of this processing wherein steam is introduced to the chamber 10 through the condenser 38 it is essential that the non-condensible gases be removed from the condenser 38 so that they will not be reintroduced to the chamber 10 and thereby to the tobacco 12 in the chamber during the steaming portion of the conditioning cycle. The most important object during conditioning, of course, is to introduce only water vapor to the chamber during steaming so that there will be no cold spots and thereby the tobacco may be uniformly conditioned in optimum conditioning time.

The condenser 38 is provided with a transducer 96 adapted to measure the condition of a variable inside the condenser. The transducer may be in the form of a pneumatic or electric sensing device of the type known in the control art for measuring the condition of a function and converting the measurement to a pneumatic or electric signal proportional to the measured level of said condition. The signal proportional to the measured level of the condition is fed through means, indicated at 98, to the control element 100 of the flow control valve 72. The control element 100 is moved in response to the signal to a position which is a function of the measured level of the variable condition Within the condenser to vary the rate of flow of cooling water to the condenser by opening or closing the closure element of valve 72 in accord with the signal feedback from the transducer 96.

The transducer 96, in this present invention, preferably is an absolute pressure controller and is adapted to measure the absolute pressure in the condenser 38. The sig nal fed to the control valve 72 is directed to control the rate of cooling Water from supply 66 to keep the absolute pressure in the condenser at a level above the dead end level of the second stage ejector 48 so that the non-condensible gas Will be removed from the condenser and exhausted to atmosphere. The transducer 96 is adjusted to respond to the need of the predetermined absolute pressure level in the condenser to control the position of the valve 72 and thereby the rate of flow of water to the condenser 38 during evacuation of the apparatus prior to steaming. It should be observed that the transducer 96 may be a thermally responsive device adapted to measure the sensible heat in the space 39 and to control the flow of cooling water in accord with the measured temperature level. Temperature, of course, is a function of the absolute pressure. A device of this type may be acceptable due to .low initial cost, acceptable control response, and durability in use. The controller 100 may serve to move the valve closure member of valve 72 to full open or full closed position in accord with the magnitude or character of the signal from transducer 96. Thus, in one position flow of cooling water to the condenser 38 may be terminated.

Operating control ofthe moistening process and equipment may be achieved with an automatic controller 102. The controller 102 includes a timer 104, which timer may be an electric motor having a geared shaft. The

valves

28, 42, 62, 70 and 58 may be automatically operated valves actuated by compressed air controlled by pilot valves. The

pilot valves

28a, 42a, 62a, 70a and 60a are installed in the automatic controller 102 and may be operated by cams carried on the shaft of the timer 104. Pilot valve 70a is provided only to open valve 70 to permit introduction of water to the condenser space 39. The rate of flow of Water through conduit 68 to the plate 74 will be governed by the flow control valve 72 in the manner set forth hereinbelow. Timer 104 also operates a cam-operated switch 78a which controls the energization of electric motor 78 which drives the water pump 76. The automatic controller 102 has a temperature controller 106 which is connected to a bulb 10611 in water in a pan 108 on the top of the chamber below the opening 22. The temperature controller operates to turn on the timer 104 after a predetermined temperature has been reached. The timer has a cam Which, after a predetermined time, resets the temperature controller 106 so that it will energize the timer 104 at a new predetermined temperature. Such a temperature controller is described in Taylor Instrument Companies Bulletin 98,159 of April, 1953.

Operation of the conditioning cycles with the apparatus herein described is commenced by placing the hogsheads of tobacco 12 within the chamber 10 and sealing the

doors

14 and 16 at either end to provide an air-tight chamber area. The temperature of the water in the pan 108 will be about 120 degrees Fahrenheit from the previous conditioning cycle. At this point in the cycle all of the automatically operable valves are closed and the pump motor 78 is de-energized.

In the process of the present invention the controller 102 is programmed to permit the second stage ejector 48 to begin the cycle and to operate for a predetermined period to evacuate the condenser space 39. The second stage ejector 48 is rendered operative by opening of valve 62 by pilot valve 62a. This will permit the introduction of steam to the low pressure side 50 of the ejector 48. Simultaneously with the opening of valve 62 the pilot valve 60a operates to open the valve 58 through the air cylinder operator 60 to permit discharge of the steam to atmosphere. In one particular installation and with a second stage ejector with a varying capacity of zero pounds per hour at 1.6 inches of mercury absolute pressure to 6,600 pounds per hour at 30 inches of mercury absolute pressure I found that after about seven minutes of operation the absolute pressure in the condenser space was reduced to about 1.6 inches of mercury, the dead end point of the ejector employed. From the table of Properties of Saturated Steam-Temperature it will be found that 1.6 inches of mercury absolute pressure corresponds to about 94 F.

Thus, at T the second stage ejector is rendered operative and is effective to begin evacuation of the condenser space 39. At time T and during continued evacuation of the space 39, the absolute pressure in the chamber 10 is reduced to a point where the water therein begins to vaporize taking away heat and lowering the temperature of the water in pan 108. At time T the

valves

42 and 70 are opened by the controller 104 and the pump motor 78 is energized to begin pumping action by the pump 76. Opening of valve 70 permits the circulation of water through the condenser 38 and opening of valve 42 begins the operation of the first stage ejector. When the first stage ejector 32 is operating the chamber 10 is quickly evacuated to remove vapor and non-condensibles therefrom. The vapor is condensed and in the condenser space 39 while the non-condensibles are discharged to atmosphere through the second stage ejector 48.

During operation of the first stage ejector, the vapor passing from the discharge side 36 thereof into condenser space 39 will, of course, be at relatively high temperatures. In our specific example, noted above, if the vapors in the space 39 are maintained below 94 F. the absolute pressure in the condenser 38 will remain at about 1.6 inches of mercury. If, however, the vapors in condenser space 39 rise to, for example, F., then the absolute pressure will rise to about 1.933 inches of mercury. Sufficient Water will vaporize in this condition to satisfy the capacity of the second stage ejector. The first stage ejector 32 remains operative until the pressure in the chamber 10 is reduced to the dead end point of said ejector.

It has 'been considered to be good operating practice, when conditioning tobacco with equipment of the type noted herein, to provide condenser cooling water at as low a temperature as feasible. The theory of this operating practice is that with colder condenser water the first stage ejector will evacuate the chamber 10 to a slightly lower absolute pressure than it would if the process were operated at design conditions. I have discovered the surprising fact that careful control of the temperature of the condenser water will eliminate the cold spots (unconditioned areas) in the tobacco being conditioned to assure a uniformly conditioned product regardless Otf the ambient conditions under which the process is carried out. Such conditioning control is difficult to achieve with present operating methods and equipment.

I have noted that the cold spots in the tobacco tend to occur when the process is carried out under conditions wherein the body of tobacco may be introduced to the chamber 10 while relatively cool (e.g. about 40 F.)as occurs during winter in the higher latitudes-and wherein the cooling water employed in the process (or the waste water if a waste Water conditioning process is being employed) also is relatively cool.

If, for example, the body of tobacco is taken directly from a warehouse without prior warming and introduced to the chamber at about 40 F. then it is apparent that the chamber temperature must be lowered below 40 F. in order to flash the moisture from the center of the body of tobacco to flush out the non-condensibles trapped therein. It should be noted that the temperature of operation of the process is a function of the absolute pressure in the system and to that extent as a measured condition, may be interchangeable therewith in function for operation of the process in the manner desired. If the condenser water supply also is at about 40 F. the second stage ejector will dead end at about 1.6 inches of mercury absolute. If the water flow is not carefully controlled or is adjusted to permit large temperature rises in accord with design of the equipment (for example, if the condenser is regulated for operation under ambient conditions higher than the relatively cool conditions described) the water flow will be sufficient to permit continued cooling of the space 39. Under such operating conditions the temperature in space 39 may rise to the design maximum, 15 F. for example, resulting in a temperature of 55 F. (40 F. and 15 F.). From the tables of Properties of Saturated Air-Vapor Mixtures it can be seen that at 1.6 inches of mercury absolute pressure at 55 F. the percent of dry air, by weight, in a mixture of air saturated with water vapor is 82%. It can readily be seen that an appreciable amount of air will remain in the condenser space 39 under such conditions.

With my apparatus and process the quantity of cooling water to the condenser space 39 will be reduced in accord with the control function of the transducer 96 acting upon the valve 72 so that the operating steam from the discharge of the first stage ejector plus the vapor from the tobacco will elevate the sensible temperature in space 39 (for example, to 100 F.). The corresponding absolute pressure noted in the tables will be 1.933 inches mercury. This same table will indicate that zero percent of air is present at this condition. The second stage ejector can effectively remove the non-condensibles from the space 39 since at this absolute pressure the second stage ejector has an appreciable air handling capacity and would scrub the air out of the space 39 to a point where the ejector was being satisfied by the vapor being boiled off of the condenser water.

At time T the second stage ejector is shut down by closing

valves

58 and 62, the first stage ejector is shut down by closing valve 42 and the supply of cooling water is terminated by closing valve 70. Valve 58 is closed and steam is introduced to the condenser space 39 from the steam supply 40. The steam then flows from the condenser space 39 through the first stage ejector 32, through conduit 24 and into the conditioning chamber 10.

When the steam is introduced directly into a chamber from a source it is in the super-heated stage because of the expansion of the steam and the pressure reduction. In this condition moisture must be added from an external source of water to produce the necessary moistening of the product. However, in the present apparatus and with the process herein described, the supplementary addition of moisture is not required. As the steam passes through the condenser space 39 and the ejector 32, sufiicient heat is absorbed by these structures before the steam is introduced into the chamber to bring the steam to a saturated state to moisten the product.

The temperature within the chamber 10 rises when the steam is introduced until it reaches a predetermined value as established by the temperature control 106 which value may, for example, be 150 F. When this temperature is reached at T the timer 104 is actuated by .the temperature controller 106 in response to said temperature level.

' At time T the valve 58 is opened and re-evacuation of the chamber is resumed. Re-evacuation and steaming are repeated as indicated at T through T to assure uniform conditioning of the tobacco within the chamber 10. At time T the steam fiow to chamber 10 through the condenser 38 is again terminated and the second stage ejector 48 is rendered operative to resume evacuation by said ejector. At time T valve 70 is opened by the controller 102 to begin the flow of water to the condenser space. Before the time T the timer motor actuates the temperature controller 106 to lower the predetermined temperature at which the controller 106 energizes the timer 104. This new predetermined temperature may be, for example, F. At time T the fiow of water to the condenser is again terminated, the.

ejector 48 is rendered inoperative, and the valve 28 is opened to break the vacuum in said chamber at time T It should be observed that an isolating valve may be employed in the place of the vacuum breaker valve 28 Without altering the operation of the process disclosed herein.

While a specific embodiment of the present invention is shown and described it will, of course, be understood that process modifications and alternative constructions may be used without departing from the true spirit and scope of the invention. It isintended by the appended claims to cover all such process modifications and alternative constructions as fall within their true spirit and scope.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. An improved apparatus for conditioning tobacco and having a cooling water supply, said apparatus comprising: a hermetically scalable conditioning chamber having means for insertion and removal of said tobacco; a first steam ejector having a low pressure side and a discharge side, the low pressure side of said ejector being in communication with the conditioning chamber; a condenser connected to the discharge side of said first steam ejector, said condenser being connected through flow control means to the cooling water supply; a second steam ejector having a low pressure side and a discharge side, the low pressure side being in communication with said condenser; transducer means responsive to the pressure condition in the condenser and operatively connected to control means to control the flow of cooling water to said condenser and thereby to control the pressure condition within the condenser to a predetermined level above the dead end level of the second steam ejector; and means for introducing steam to the conditioning chamber.

2. An improved apparatus for conditioning tobacco and having a cooling water supply, said apparatus comprising: a hermetically scalable conditioning chamber having means for insertion and removal of said tobacco; a first steam ejector having a low pressure side and a discharge side, the low pressure side of said ejector being in communication with the conditioning chamber; a condenser connected to the discharge side of said first steam ejector, the cooling water supply being connected to said condenser through flow control means; a second steam ejector having a low pressure side and a discharge side, the low pressure side being in communication with said condenser; transducer means responsive to the condition of the vapor in the interior of the condenser and operatively connected to the flow control means to control the flow of cooling water from the cooling water supply to said condenser thereby being effective to control the vapor condition within the condenser to a predetermined level; and means for introducing steam to the conditioning chamber.

3. An improved apparatus for conditioning tobacco and having a cooling water supply, said apparatus comprising: a hermetically scalable conditioning chamber having means for insertion and removal of said tobacco; a first steam ejector having a low pressure side and a discharge side, the low pressure side of said ejector being in communication with the conditioning chamber; a condenser connected to the discharge side of said first steam ejector, said condenser being connected to the cooling water supply; an automatic control valve interposed in the fluid connection between the cooling water supply and condenser to control the rate of flow of cooling water to the condenser;

a second steam ejector having a low pressure side and a discharge side, the low pressure side being in communication with said condenser; transducer means responsive to the pressure condition in the condenser and operatively connected to the control valveto position said valve for delivery of a measured amount of coo-ling water to the condenser to control the pressure condition in the condenser to a predetermined level above the dead end level of the second steam ejector; and means for introducing steam to the conditioning chamber.

4. An improved apparatus for conditioning tobacco and having a cooling water supply, said apparatus comprising: a hermetically sealable conditioning chamber having means for insertion and removal of said tobacco; a first steam ejector having a low pressure side and a discharge side, the low pressure side of said ejector being in communication with the conditioning chamber; a condenser connected to the discharge side of said first steam ejector, the cooling Water supply being connected to said condenser through flow control means; a second steam ejector having a low pressure side and a discharge side, the low pressure side being in communication with said condenser; thermally responsive means operatively connected to the interior of the condenser and to the floW control means and eifective to position the flow control means to control the flow of cooling water from the cooling water supply to said condenser and thereby to control the temperature within the condenser to a predetermined level; and means for introducing steam to the conditioning chamber through the condenser and first ejector.

5. An improved process for conditioning tobacco by moistening it with steam in a system including a conditioning chamber, a condenser, cooling water supply for said condenser, a steam ejector to evacuate the chamber and discharging into the condenser, and an evacuator for the condenser, said process comprising the steps of: evacuating said condenser to a predetermined pressure level; introducing steam to said steam ejector to evacuate the chamber while continuing evacuation of said condenser with said condenser evacuator; introducing cooling water to the condenser and automatically controlling the rate of introduction of the cooling water in response to the transient vapor condition within said condenser; ceasing evacuation of the chamber and condenser when said chamber and condenser are at predetermined pressure levels, respectively, and isolating the cooling water supply from the condenser when said pressure levels are reached; and, passing super-heated steam into the condenser whereby said super-heated steam is conditioned prior to introduction to the conditioning chamber by cooling in passage through the condenser and steam ejector to the conditioning chamber to a safe level for conditioning of the tobacco and to place the steam in the saturated vapor state.

6. An improved process for conditioning tobacco by moistening it with steam in a system including a conditioning chamber, a condenser, cooling water supply for said condenser, a steam evacuator to evacuate the conditioning chamber and an evacuator for the condenser, said process comprising the steps of: introducing steam to said steam evacuator to evacuate the chamber while evacuating said condenser with said condenser evacuator to predetermined pressure levels, respectively; introducing cooling water to the condenser and controlling the rate of intro duction of cooling water in response to and as a function of the transient vapor condition in the condenser to control the vapor condition within said condenser; isolating the chamber and condenser evacuators from the system when said chamber and condenser are at a predetermined pressure level and isolating the cooling water supply from the condenser when said pressure levels are reached; and, passing super-heated steam into the condenser whereby said super-heated steam is conditioned prior to introduction to the conditioning chamber by cooling in passage through the condenser to the conditioning chamber to a safe level for conditioning of the tobacco and to place the steam in the saturated vapor state.

7. An improved process for conditioning tobacco by moistening with steam in a system including a conditioning chamber, a condenser, cooling water supply for said condenser, and an evacuator for the chamber and condenser, respectively, said process comprising the steps of: simultaneously evacuating the chamber and condenser to predetermined pressure levels, respectively; introducing cooling water to the condenser and automatically controlling the rate of introduction of the cooling water in response to and as a function of the transient vapor condition in the condenser to control the vapor condition within said condenser; isolating the chamber and condenser evacuators from the system when said chamber and condenser are at a predetermined pressure level, respectively, and isolating the cooling water supply from the condenser when said pressure levels are reached; and, passing super-heated steam into the condenser whereby said super-heated steam is conditioned prior to introduction thereof to the conditioning chamber by cooling in passage through the condenser to the conditioning chamber to a safe level for conditioning of the tobacco and to place the steam in the saturated vapor state.

References Cited by the Examiner UNITED STATES PATENTS 2,217,935 10/1940 Smith et al 131-140 2,245,833 6/1941 Smith et a1 131-133 2,285,331 6/1942 Doyle 131133 2,285,469 6/ 1942 Smith et al. 131-140 2,528,476 10/1950 Roos et a1.

2,621,492 12/1952 Beardsley et al 131133 2,832,353 4/1958 Doyle 131-133 2,997,046 8/1961 Doyle 131-433 3,124,142 3/1964 Philbrick et al. 131133 SAMUEL KOREN, Primary Examiner.

P, DEELEY, Assistant Examiner.

Claims

1. AN IMPROVED APPARATUS FOR CONDITIONING TOBACCO AND HAVING A COOLING WATER SUPPLY, SAID APPARATUS COMPRISING: A HERMETICALLY SEALABLE CONDITIONING CHAMBER HAVING MEANS FOR INSERTION AND REMOVAL OF SAID TOBACCO; A FIRST STEAM EJECTOR HAVING A LOW PRESSURE SIDE AND A DISCHARGE SIDE, THE LOW PRESSURE SIDE OF SAID EJECTOR BEING IN COMMUNICATION WITH THE CONTDITIONING CHAMBER, A CONDENSER CONNECTED TO THE DISCHARGE OF SAID FIRST STEAM EJECTOR, SAID CONDENSER BEING CONNECTED THROUGH FLOW CONTROL MEANS TO THE COOLING WATER SUPPLY; A SECOND STEAM EJECTOR HAVING A LOW PRESSURE SIDE AND A DISCHARGE SIDE, THE LOW PESSURE SIDE BEING IN COMMUNICATION WITH SAID CONDENSER; TRANSDUCER MEANS RESPONSIVE TO THE PRESSURE CONDITION IN THE CONDENSER AND OPERATIVELY CONNECTED TO CONTROL MEANS TO CONTROL THE FLOW OF COOLING WATER TO SAID CONDENSER AND THEREY TO CONTROL THE PRESSURE CONDITION WITHIN THE CONDENSER TO A PREDETERMINED LEVEL ABOVE THE DEAD END LEVEL