US2871574A

US2871574A - Drier apparatus

Info

Publication number: US2871574A
Application number: US552883A
Authority: US
Inventors: Thies Alfred Friedric Bernhard
Original assignee: Individual
Current assignee: Individual
Priority date: 1951-03-21
Filing date: 1955-12-13
Publication date: 1959-02-03
Anticipated expiration: 1976-02-03

Description

Feb. 3, 1959 AR B. THIES" DRIER APPARATUS Filed Dec. 13, '1955 Unite States The present invention relates to a drier apparatus.

More particularly, the present invention relates to a drier apparatus which is adapted to dry textile materials or the like.

There exist drier apparatuses wherein bobbins or spools of textile material and the like are exposed to a suitable gaseous drying medium. The arrangement is usually such that the gaseous drying medium is circulated through a suitable drying chamber within which the bobbins or spools of textile material are contained. The gaseous drying medium is, before being passed through the drying chamber, heated to a sufliciently high temperature, and after the gaseous drying medium leaves the drying chamher, it is subjected to the action of a suitable moisture extractor for moving accumulated moisture from the drying medium. In known structures, provision is usually made for passing the gaseous drying medium through the drying chamber in but one direction, so that the drying action is relatively inefiicient. Moreover, in known apparatus the entire drying process requires considerable periods of time.

It is therefore an object of the present invention to provide a drying apparatus which overcomes the above disadvantages.

It is another object of the present invention to pro vide a drying apparatus which will rapidly and efficiently dry bobbins or spools of textile material or the like.

The objects of the present invention also include the provision of a drying apparatus in which a gaseous drying medium may be passed through the materials to be dried in opposite directions.

It is still another object of the present invention to provide a drying apparatus wherein the direction in which a gaseous drying medium is passed through the materials to be dried is controlled automatically.

It is a still further object of the present invention to provide a drier apparatus wherein the extent to which the material to be dried has been dried controls the direction in which the gaseous medium passes through the material.

It is yet another object of the present invention to provide a drier apparatus which operates completely automatically and consequently requires a minimum of supervision.

It is also an object of this invention to provide a drying apparatus which is provided with suitable control means for controlling the individual components of the apparatus.

A still further object of this invention is the provision of a drier apparatus which will automatically terminate operation as soon as the drying process is completed.

With the above objects in view the present invention mainly resides in a drier apparatus which includes a closed receptacle defining a chamber and having spaced opening means each placing the chamber in communication with the exterior thereof. A combined blower, heater and moisture extractor means having inlet and outlet means is provided, thus combined blower, heater and moisture extractor being hereinafter referred to, in

ate'nt O both the specification and claims, as a conditioning means. The conditioning means includes a blower, a heater and a moisture extractor in cascade connection, with the heater being nearer to the outlet means than the moisture extractor, and in the preferred embodiment the blower is arranged intermediate the moisture extractor and the heater. The conditioning means serve to move a gaseous drying medium from the inlet means to the outlet means while at least partially extracting moisture from the gaseous medium, thereby at least partly drying the same, and thereafter heating the thus-dried gaseous medium.

The blower includes drive means for driving the same and'the drive means in turn include drive actuator means for actuating the drive means. The drive actuator means is movable between on and off positions. The heater includes heating means and heating means in turn include heating actuator means for actuating the heating means. The heating actuator means is movable between on and off positions. Similarly, the moisture extractor includes cooling means and the cooling means in turn include cooling actuator means for actuating the cooling means. The cooling actuator means is movable between on and off positions.

The drier apparatus further includes connecting means in communication with the opening means of the receptacle and with the inlet and outlet means of the conditioning means'for placing the receptacle and the conditioning means in closed circuit communication with each other. The connecting means are movable between a first position wherein the inlet means of the conditioning means is in communication with one of the opening means of the receptacle and wherein the outlet means of the conditioning means is in communication with the other of the opening means of the receptacle, and a second position wherein the inlet means is in communication with the other opening means and wherein the outlet means is in communication with the one opening means.

First temperature-responsive operating means are located at the inlet means of the conditioning means and are connected to the connecting means for maintaining the same in one of its positions while the temperature of the gaseous medium entering the conditioning means is below a predetermined temperature, for moving the connecting means to the other of its positions when the tem-. perature of the gaseous medium entering the conditioning means attain this predetermined temperature, for maintaining the connecting means in its other position while the temperature of the gaseous medium entering the conditioning means is equal to at least this predetermined temperature but is below a predetermined higher temr perature, and for moving the connecting means back to its one position when the temperature of the gaseous medium entering the conditioning means attains this predetermined higher temperature.

Second temperature-responsiv'e control means are 10- 1 cated at the inlet means of the conditioning means and are connected to each of the above mentioned actuator means for moving the same to their respective ofi positions when the temperature of the gaseous medium entering the conditioning means attains a predetermined still higher temperature.

By virtue of the above arrangement, an at least partly dried and heated gaseous drying medium may be passed through the receptacle in one direction while the temperature of the gaseous medium entering the conditioning means is below this predetermined temperature, in the opposite direction when the gaseous medium entering the conditioning means is equal to at least this predetermined temperature but is below this predeter mined higher temperature, and. again in the one direction when the gaseous medium entering the conditioning means, attain this predetermined higher tempera- '3 ture. The material within the chamber of the receptacle is thus dried. Also, when the gaseous medium entering the conditioning means attains this predetermined still higher temperature, each of the actuator means is moved to its respective off position, thereby deactivating the drive means and consequently the blower, the heating means and consequently the heater, and cooling means and consequently the moisture extractor. This brings about the cessation of circulation of gaseous drying medium through the receptacle, the heating of gaseous medium by the heater, and the extracting of moisture from the gaseous medium by the moisture extractor.

If desired, additional temperature-responsive operating means may be located between the heater and the outlet means of the conditioning means and be connected to the heateractuator means for moving the same to its olf position when the temperature of the gaseous drying medium heated by the heater attains a predetermined temperature. In this way, when the heater heats the gaseous drying medium so that the same attains this last-mentioned predetermined temperature the operating means moves the heating actuator means to its off position, thereby deactivating the heating means and consequently the heater. The heater is thus prevented from heating the gaseous drying medium to a temperature exceeding this last-mentioned predetermined temperature.

If desired, additional temperature-responsive operat' ing means may be located between the moisture extractor and the heater and be connected to the cooling actun ator means for moving the same to its off position when the temperature of the gaseous medium the moisture .of which has been extracted by the moisture extractor is below a predetermined temperature. In this way,

when the cooling means cools the gaseous medium passing through the moisture extractor to a temperature below this last-mentioned predetermined temperature, the operating means moves the cooling actuator means to its off position, thereby deactivating the cooling means and consequently the moisture extractor. The cooling means is thus prevented from cooling the gaseous medium passing through the moisture extractor to a temperature below this last-mentioned predetermined temperature.

The drier apparatus according to the present invention may also be provided with manually operable vent means in communication with the receptacle for placing the same, and consequently the closed circuit formed by the receptacle, the conditioning means, and the connecting means, in communication with atmosphere. As a result, the receptacle, and consequently the closed circuit may, whenever desired, be vented manually. Also, manually operable valve means may be located at the inlet and outlet means of the conditioning means opening and closing the same, so that the receptacle and the conditioning means may, if desired, be placed out of communication with each other manually.

Also, a source of gaseous medium under pressure may be in communication with the receptacle or with the closed circuit formed by the receptacle, the conditioning means, and the connecting means, for automatically maintaining the pressure in the receptacle above a predetermined pressure.

In the preferred embodiment the closed receptacle defines a substantially cylindrical chamber adapted to receive a substantially tubularly shaped mass of material or any other mass of material which is arranged in such a manner as to have an interior space. Such receptacle is provided with inner and outer opening means each placing the chamber in communication with the exterior thereof. The inner opening means is ar ranged so that it communicates with that portion of the chamber which is coincident with the interior space of the mass of material while the latter is received within the chamber and the outer opening means is arranged v so that it communicates with that portion of the chamber which encompasses the mass of material. The connecting means which is associated with the above described receptacle is movable between a first position wherein the inlet means of the conditioning means is in communication with the inner opening means of the receptacle and wherein the outlet means of the conditioning means is in communication with the outer opening means of the receptacle, and a second position wherein the inlet means is in communication with the 'outer opening means and wherein the outlet means is in communication with the inner opening means. In this way, when the connecting means is in its first position, an at least partly dried and heated gaseous medium may be passed through the mass of material from the outside thereof to the inside thereof, and when the connecting means is in its second position an at least partly dried andheated gaseous medium may be massed through the mass of material from the inside thereof to the outside thereof.

This application is a continuation-in-part application of my copending application Serial No. 277,100, filed March 18, 1952, now Patent No. 2,739,392 dated March 27, 1956, and discloses and claims a drying apparatus capable of carrying out the process disclosed and claimed in said copending application. Patent No. 2,739,392 has been reissued as Patent No. Re. 24,260 dated December 25, 1956.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read inconnection with the accompanying drawings, in which:

Fig. 1 is a schematic. showing of apreferred embodiment of the present invention, the parts being shown in one operative positiomand Fig. 2 is a fragmentary schematic showing of a part of the embodiment illustrated in Fig. l, with. the parts being shownin another operative position.

Referring now to the drawing, there is shown a preferred embodiment of a drier apparatus according to the present invention. The drier apparatus includes a closed receptacle 1%) which defines a substantially cylindrical drying chamber 11 adapted to receive a mass of material which is arranged in such a manner as to have an interior space. The mass of material may be constituted by a tubularly shaped bobbin or spool 12 of thread or yarn or the like which is supported within the chamber 11 in any suitable manner.

The receptacle 10 is formed with spaced inner and outer opening means 13 and 14, both of which place the chamber 11 in communication with its exterior. The inner opening means 13 communicates with: that portion of the chamber which is coincident with the interior portion 15 of the bobbin i2 and the outer opening means 14 communicates with that portion of the chamber which encompasses or surrounds the bobbin 12. In this way, a gaseous medium which is introduced through the opening means 1-3 andle-aves the receptacle iii through the opening means 14 will pass through the bobbin 12 from the inside thereof to the outside thereof, and a gaseous medium which is introduced through the opening means 1 4 and leaves the receptaclelt) through the opening means 13 will pass through the bobbin 12 from the outside thereof to the inside thereof.

It will be understood from the above that if the material constituting the bobbin 12 is wet, a suitable gaseous drying medium may be passed through the bobbin 1?. either from the inside thereof to the outside thereof or vice versa.

The drier apparatus further includes a combined blower,

heater and moisture, extra'ct'ormeans 2t) io'r'preparing and moving a gaseous drying medium through the recepe.

tacle 10, The combined blower, heater and moisture extractor means 20, which, as set forth above, are vhereinafter referred to as conditioning means, includes a blower 30, a heater 40 and a moisture extractor 50 arranged in cascade or series connection, the inlet means of the conditioning means 26 being indicated at 21 and the outlet means thereof at 22. The heater is nearer to the outlet means 22 than the moisture extractor 50, and the blower 30 is preferably, though not necessarily, arranged intermediate the moisture extractor 5t) and the heater 40.

The blower 30 serves to move a gaseous medium from the inlet means 21 to the moisture extractor 50 and from there to the heater 40, in the direction of the arrows 23, so that the gaseous medium is expelled from the combined blower, heater and moisture extractor means through its outlet means 22. The blower includes suitable drive means 31, such as an electric motor, and the drive means 31 in turn include drive actuator means 32 which may be a suitable switching arrangement for.

actuating the motor. The drive actuator means 32 is movable between on and off positions, so that the blower 30 may be activated and deactivated.

The heater includes suitable heating means 41 which may be a steam or electrical heating arrangement. In the illustrated embodiment, the heating means 41 is steam operated and is connected to a suitable source of steam (not shown). The heating means 41 includes a heating actuator means 42 which may take the form of a valve suitably arranged in the steam inlet of the heating means 41. The valve 42 is movable between on and ofl, i. e. open and closed, positions so that the heating means 41 may be activated and deactivated.

It will be seen that when the valve 42 is in its open position, a gaseous medium flowing through the heater 40 will be heated.

If desired, a manually-operated by-pass valve 43 may be provided enabling manual activation of the heating means 41' while the valve 42 is in its closed position.

Also, a suitable steam trap or steam condenser (not shown) may be provided at the outlet of the heating means 41.

The moisture extractor includes a suitable cooling means or moisture condenser 51. The latter may take the form of apipe or heat exchange arrangement through which cooling water flows. The cooling means 51 is connected to a suitable source of cooling water (not shown) and includes a cooling actuator means 52 which may take the form of a valve suitably arranged in the cooling water inlet. The valve 52 is movable between on and oif, i. e. open and closed, positions, so that the cooling means 51 may be activated and deactivated. The condensed water extracted from the gaseous medium passing through the moisture extractor 50 may be removed at 54. i

It will be seen that when the valve 52 is in its open position, a moist gaseous medium flowing through the moisture extractor 50 will be cooled. Consequently, the moisture contained in such gaseous medium will be at least partially condensed and extracted, so that the gaseous medium is at least partly dried.

If desired, a manually-operated by-pass valve 53 may be provided enabling manual activation of the cooling means 51 while the valve 52 is in its closed position.

It is clear from the above that the blower 30, the heater 40 and the moisture extractor 50 together constitute the conditioning means 20 which serves to move a gaseous medium from the inlet means 21 to the outlet means 22 while at least partially extracting moisture from the gaseous medium, thereby at least partly drying the same, and thereafter heating the thus-dried gaseous medium. 7

Suitable connecting means are provided for placing the receptacle 10 in closed circuit communication with the conditioning means 20. The connecting-means include a four-way valve 61 and four

conduits

62, 63, 64 and 65, the arrangement being such that when the fourway valve 61 is in its first position, illustrated in Fig. 1, the outlet 22 of the conditioning means 20 is in communication with the outer opening means 14 of the receptacle 10 by way of the

conduits

62 and 63 and the inlet 21 is in communication with the inner opening means 13 by way of the

conduits

64 and 65. When the four-way valve 61 is in its second position, illustrated in Fig. 2, the outlet 22 is in communication with the inner opening means 13 by way of the

conduits

62 and 64 and the inlet 21 is in communication with the outer opening means 14 by way of the

conduits

63 and 65.

From the above, it Will be clear that a gaseous medium circulated by the blower 30 will, when the four-Way valve 61 is in its first position, flow through the connecting means 61) and the receptacle 10 in the direction of the arrows a (Fig. 1), so that the gaseous medium passes through the bobbin 12 from the outside thereof to the inside thereof. Contrariwise, when the four-way valve 61 is in its second position, a gaseous medium circulated by the blower 30 will flow through the connecting means 60 and the receptacle 10 in the direction of the arrows b (Fig. 2), so that the gaseous medium passes through the bobbin 12 from the inside thereof to the 2 closed so that the receptacle and the conditioning means outside thereof.

Irrespective of the position of the four-way valve 61, the operation of the device, as described so far, is as follows:

When the conditioning means 20 is in closed circuit communication with the receptacle 10, the blower 30 will move a gaseous medium in the closed circuit through the receptacle 10 and into the inlet means 21. If the receptacle 10 contains a Wet material, the gaseous medium will, while moving through the receptacle 10, absorb moisture contained in the material. Initially, the gaseous medium, in addition to absorbing the moisture, may carry water droplets along mechanically, and the gaseous medium entering the conditioning means 20 will therefore contain a certain amount of moisture. This moisture will be at least partially extracted by the moisture extractor 50, so that the gaseous medium leaving the moisture extractor 50 will have been at least partiallydried. The thus-dried gaseous medium is thereupon continued to be moved through the conditioning means 20 in the direction of the arrow 23 to the heater 40. The latter will raise the temperature of the gaseous medium, which thereupon leaves the conditioning means 20, through its outlet means 22, as a gaseous drying medium. This gaseous drying medium is then recirculated through the drier 10 where it will absorb more moisture, after which it will be reintroduced into the conditioning means 20 through its inlet means 211.

The above cycle is then repeated until the material within the receptacle 10 has attained the desired degree of dryness.

If desired, the conditioning means 20 may be provided with manually operable valves 25 located at or near the inlet means 21 and the outlet means 22, respectively. The inlet and outlet means may. thus be 20 may, if desired, be placed out of communication with each other manually, thereby facilitating cleaning or adjustment of either of the components, or of both.

Also, suitable valves 26 and conduits 27 may be pro vided for isolating from each other the several components constituting the conditioning means 20, and for placing, whenever desired, the close circuit in communication with other apparatus.

Furthermore, the receptacle 10 may be provided with vent means which include a conduit 16 in communication with atmosphere and with the chamber 11. The conduit 16 may include a valve 17, which may be a manually operable one, so that the chamber 11 and garners consequently the closed circuit formed by the receptacle 10, the conditioning means 24) and the connecting means 60 ma whenever desired, be vented.

Moreover, a suitable source 18 of gaseous medium under pressure may be provided which is in communication with the recepetacle 1t) and which automatically maintains the pressure within the chamber 11 above a predetermined pressure. It has been found that the efficacy of the drying is greatly enhanced by the presence of superatmospheric pressure within the drying chamber. In this connection, reference is made to the above-mentioned copending application.

If desired, a valve 19, which may be a manually operable one, may be interposed in the conduit connecting the source 18 and the receptacle 10.

Additionally, the conduit 64 which places the inner opening means 13 of the receptacle in communication with the four-Way valve 61 may be provided, at its lowermost portion, with a drainage conduit 66, thereby facilitating draining of the conduit 64. A suitable valve 67 is included in the conduit 66 for opening and closing the same.

As set forth above, the fourway valve 61 is movable between first and second positions so that a gaseous drying medium may be passed through the container in opposite directions, i. e., so that the gaseous drying medium may be passed through the bobbin 12 either from the inside thereof to the outside thereof or vice versa.

It has been found that the drying operation may be accomplished most efficiently by varying, during the drying operation, the direction in which the gaseous drying medium is passed through the bobbin. In particular, it has been found that the direction of flow of the gaseous drying medium through the bobbin should be dependent upon the degree of dryness of the material to be dried, and it is therefore within the scope of the present invention to provide an automatic operating mechanism by means of which the four-way valve 61. is moved between its two positions in accordance with the degree of dryness of the material to be dried.

It has also been found that the temperature of the gaseous drying medium leaving the receptacle 10 after it has passed through the bobbin is a function of the degree of dryness of the material to be dried. Inasmuch as the temperature of the gaseous drying medium leaving the receptacle 10 is substantially equal to the temperature of the gaseous drying medium entering the conditioning means 29, a suitable temperature-responsive or thermostatic control device 70 may be located at or near the inlet means 21. The thermostatic control device is connected to the four-way valve 61 in such a manner as to move the same between its two positions as a function of the temperature of the gaseous medium entering the conditioning means 20.

It has further been found that the drying process may be best accomplished in three steps, the first being the preliminary drying or squeezing step in which the gaseous drying medium is passed from the outside of a bobbin to its inside, the second being the main drying step in which the gaseous drying medium is passed from the inside of the bobbin to its outside, and the third being the finishing step in which the gaseous drying medium is again passed from the outside of the bobbin to its inside.

Accordingly, the thermostatic control device 70 is interconnected to the four-way valve 61 in such a manner that the four-way valve is maintained in its first position, illustrated in Fig. 1, while the temperature of the gaseous drying medium entering the conditioning means 20 is below a predetermined temperature. When the tempcrature of the entering gaseous medium attains this predetermined temperature, the four-way valve 61 is automatically moved to its second position, illustrated in Fig. 2, and is maintained in this second position while responsive switching or valve mechanism.

8 the temperature. of the entering gaseous medium is equal; to at least the predetermined temperature but is below apredetermined higher temperature. When the entering gaseous medium thereafter attains this predetermined higher temperature, the four-way valve 61 is automatically moved back to its first position.

The four-way valve 61 may be a pneumatically or electrically operated one, and the thermostatic control device 7i may be constituted by a suitable temperature- In either event. the two components are interconnected with each other in a manner well known in the art. In the illustrated embodiment, valve 61 is turned by lever :610 which is articulated to a piston rod 611 carrying a piston 612. Piston 612 is movable in a cylinder 613 which is pivotally mounted on a support 614. A pump is connected by conduits to the ends of cylinder 613 and is driven by an electric motor, which is connected to the terminals of a source of voltage S.

A reversing switch 702 is shiftable to a position 702a for energizing motor M to turn in direction of the arrow,

and to a position 702b for reversing the motor. Switch 702 is mechanically connected to thermostat 70 by a linkage 701 indicated by a broken line.

When the temperature of the drying medium is below a predetermined temperature, for example 100 F., switch 702 and piston 612 are in the illustrated position. When the temperature of the drying medium attains the predetermined temperature, thermostat 70 shifts.

switch 702 to position 702a effecting rotation of the motor and pump in the direction of the arrow so that the control fluid passes into cylinder 613 and moves the piston to position 612a so that valve 61 is turned through ninety degrees to its second position illustrated in Fig. 2, in which it remains until a predetermined higher temperature is reached, for example 190 F. At this temperature, thermostat 70 shifts the switch to position 702b in which motor M is reversed and turns in direction opposite to the arrow so that valve is turned back to its initial position.

In practice, the thermostatic control device 70, which is shown as being arranged at the inlet means 21, may be located at any point intermediate the moisture extractor 50 and that opening means of the receptacle 10 which, during any given step, constitutes the outlet opening. Thus, the thermostatic control device 70 may be located along the conduit 65 which places the fourway valve 61 in communication with the inlet means 21 of the conditioning means 20.

If desired, the illustrated thermostatic control device may be replaced by two thermostatic control devices (not shown), one of which is located along the conduit 64 or at the opening means 14. Both thermostatic control devices are interconnected to the four-way valve 61 in such a manner that the first-mentioned thermostatic control device, i. e., the one located along the conduit 64 or at the opening means 13, serves to actuate the fourway valve 61 while the latter is in its first position, shown in Fig. 1, and that the other thermostatic control device, i. e., the one located along the conduit 63 or at the opening means 14, serves to actuate the four-way valve while the latter is in its second position, shown in Fig. 2.

The following is illustrative of a drying process carried out by an apparatus of the type disclosed.

A bobbin or the like having a water content of be tween 300 to 350% (i. e., the weight of the water is 3 to 3 /2 times the weight of the dry bobbin) is placed Within the chamber 11 of the receptacle 1%, and is initially subjected to the above-described squeezing step, the four-way valve 61 being in its first position so that the gaseous drying medium passes through the bobbin from its outside to its inside.

When the water content of the bobbin has been reduced to between 60 and the temperature of the gaseous medium entering the inlet means 21 of the conditioning means 20 will be between approximately 100 and 140 F. This will occur within approximately ten minutes.

With, the thermostatic control device 70 being set to move the four-way valve 61 from its first position to its second position at a predetermined temperature which lies within this range of approximately 100 to 140 F., the second or main drying step will be initiated when the entering gaseous medium attains this predetermined temperature. After the four-way valve 61 has been moved to its second position, the gaseous drying medium passes through the bobbin from its inside to its outside.

During the main drying step, which will require about thirty minutes, the water contents of the bobbin will be reduced to between and and the temperature of the gaseous medium entering the inlet means 21 will, at the completion of the main drying step, be between approximately 190 and 220 F.

With the thermostatic control valve 70 being set to move the four-way valve 61 from its second position back to its first position at a predetermined temperature which lies within this higher range of approximately 190 v and 220 F., the third or finishing step will be initiated when this last-mentioned predetermined temperature is attained. The four-way valve 61 is then moved back to its first position so that the gaseous drying medium once again passes through the bobbin from its outside to its inside.

It is desirable to discontinue the finishing step of the drying operation when the water contents of the bobbin has been reduced to between 4 and 12% so as to prevent overdrying of the material. If the material to be dried is nylon, the dried product should contain between 4 to 6% water, if the material to be dried is cotton, approximately 8% water should be retained, and if the material to be dried is wool, approximately 12% water should be retained. The desired degree of dryness will be obtained approximately five minutes after commencement of the finishing step, and the temperature of the gaseous medium entering the inlet means 21, whenthe desired degree of dryness has been attained, will be between approximately 240 and 250 F.

Accordingly, it is within the scope of the present invention to provide control means for automatically deactivating the several components of the conditioning, means as soon as the desired degree of dryness of the material to be dried has been reached. The control means include a thermostatic control device 71 which is located near or at the inlet means 21 and is responsive to the temperature of the gaseous medium entering the conditioning means 20. The thermostatic control device 71 is connected to the drive actuator means 32 of the blower 30, to the heating actuator means 42 of the heater 40 and to the cooling actuator means 52 of the moisture extractor 50 for moving each of these actuator means to their respective ofi positions when the temperature of the gaseous medium entering the conditioning means 20 has attained a predetermined temperature which lies within the last-mentioned range of approximately 240 to 250 F.

As set forth above, the drive actuator means 32 may be a' suitable switching arrangement, and the thermostatic control device 71 may include a suitable switching element electrically connected to the drive actuator means 32 for shutting off the blower when the drying operation has been completed.

As also set forth above, the heating actuator means 42 and cooling actuator means 52 may take the form of suitable valves. These valves may be pneumatically or electrically operated ones, and the thermostatic control device 71 may include suitable switching or valve elements interconnected with the actuator means 42 and 52 in a of the moisture extractor 50 and corresponds to the alternate locations set forth above in connection with the thermostatic control device 70.; Similarly, the thermostatic control device 71 may be -replaced by two thermostatic control devices (not shown) arranged as described above, it being obvious, however, that if the drier apparatus is I to be usedexclusively for performingthe above-described three-step drying process, the single thermostatic con trol device 71 may be located at any point .along that portion of the closed circuit which includes

elements

13, 64, 61, ('35, 21 and 50, it being unnecessary to replace the thermostatic control device 71 by' two thermostatic control devices inasmuch as in the above-described threestep drying process the gaseous medium leaving the receptacle 10 will, during the finishing step, do so through the inner opening means 13.

If desired, the thermostatic control devices and 71 may be incorporated in a single composite structure.

A suitable control arrangement may be provided for preventing the heater 40 from overheating the gaseous drying medium. The arrangement may include a thermostatic control device 72 which is located downstream of the heater 40 and which is electrically or pneumatically connected to the heater actuator means 42 for moving the same to its otf position when the temperature of the gaseous drying medium heated by the heater attains a predetermined temperature. In this way, the temperature of the gaseous drying medium entering the receptacle 10 is prevented from exceeding a predetermined maximum temperature.

7 Another suitable control arrangement may be provided from preventing the moisture extractor 50 from overcooling the gaseous medium. This arrangement may include a thermostatic control device 73 which is located downstream of the moisture extractor 50 and which is electrically or pneumatically connected to the cooling actuator means 52 for moving the same to its ofi' position when the temperature of the dried gaseous medium leaving the moisture extractor falls below the predetermined temperature. the dried gaseous medium leaving the moisture extractor 50 and entering the heater 40 is prevented from falling below a predetermined minimum temperature.

It will be understood that each of the elements de scribed above, or two or more together, may also find a useful application in other types of drier apparatuses differing from the types described above.

While the invention has been illustrated and described as embodied in a drier apparatus for drying bobbins or the like, it is not intended to be limited to the details shown, since various modifications and structural changes.

may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist'of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be by Letters Patent is:

1. A drier apparatus comprising, in combination, a closed receptacle defining a chamber and having spaced secured opening means each placing said chamber in communi-' cation with the exterior thereof; conditioning means having inlet and outlet means and including a blower, a

heater and a moisture extractor in cascade connection, with said heater being nearer to said outlet means than said moisture extractor, for moving a gaseous drying thereafter heating the thus-dried gaseous medium; con- In this way, the temperature of necting means in communication with said opening means of said receptacle and with said inlet and outlet means of said conditioning means for placing said receptacle and said conditioning means in closed circuit communication with each other, said connecting means being movable between a first position wherein said inlet means of said conditioning means is in communication with one of said opening means of said receptacle and wherein said outlet means of said conditioning means is in communication with the other of said opening means of said receptacle, and a second position wherein said inlet means is in communication with said other opening means and wherein said outlet means is in communication With said one opening means; and temperature-respo'nsive operating means located at said inlet means of said conditioning means and connected to saidconnecting means for maintaining the same in one of its positions while the temperature of the gaseous medium entering said conditioning means is below a predetermined temperature, for moving said connecting means to the other of its positions when the temperature of the gaseous medium entering said conditioning means attains said predetermined temperature, for maintaining said connecting means in-its other position while the temperature of the gaseous medium entering said conditioning means is equal to at least said predetermined temperature but is below a predetermined higher tem perature, and for moving said connecting means back to its one position when the temperature of the gaseous medium entering said conditioning means attains said predetermined higher temperature, whereby an at least partly dried and heated gaseous drying medium may be passed through said receptacle in one direction while the temperature of the gaseous medium entering said Conditioning means is below said predetermined temperature, in the opposite direction when the gaseous medium entering said conditioning means is equal to at least said predetermined temperature but is below said predetermined higher temperature, and again in said one direction when the gaseous medium entering said conditioning means attains said predetermined higher/temperature, thereby drying a material within said chamber of said receptacle.

.2. A drier apparatus comprising,- in combination, a closed-receptacle defining a chamber and having spaced opening means each placing said chamber in communication with the exterior thereof; conditioning means having inlet and outlet means and including a blower, a heater and a moisture extractor in cascade connection, with-said heater being nearer to said outlet means than said moisture extractor, for moving a gaseous drying medium from said inlet means to said outlet means while at least partially extracting moisture from the gaseous medium, thereby at least partly drying the same, and thereafter heating the thus-dried gaseous medium,-said blower including drive means for driving the same and said drive means in turn including actuator means for actuating said drive means, said actuator means being movable between on and off positions; connecting means in communication with said opening means of said receptacle and with said inlet and outlet means of said conditioning means for placing said receptacle and said conditioning means in closed circuit communicationwith each other, said connecting means being movable betweenra first position wherein said inlet means of said conditioning means is in communication with,

one of said opening means of said receptacle and wherein said outlet means of said conditioning means is in communication with the other of said opening means of said receptacle, and a--second position wherein said inlet zmeans is in communication with said other openingymeans and wherein said outlet means is in communication with said one opening means; first temperature-respcnsive operating means located at said inlet means of said conditioning means and connected to said connecting means f or maintaining the same in one of its positions while the temperature of the gaseous medium entering said conditioning means is below a predetermined temperature and for moving said connecting means to the other of its positions when the'temperature of the gaseous medium entering said conditioning means attains said predetermined temperature; and second temperature-responsive control means located at said inlet means of said conditioning means and conected to said actuator means for moving the same to its off position when the temperature of the gaseous medium entering said conditioning means attains a predetermined higher temperature, whereby an at least partly dried and heated gaseous drying medium may be passed through said receptacle in one direction while the temperature of the gaseous medium entering said conditioning means is below said predetermined temperature and in the opposite direction when the gaseous medium entering said conditioning means attains said predetermined temperature, thereby drying a material within said chamber of said receptacle, and whereby when the gaseous medium entering said conditioning means attains said predetermined higher temperature, said actuator means is moved to its off position, thereby deactivating said drive means and consequently said blower so as to bring about the cessation of circulation of gaseous drying medium through said receptacle.

3. A drier apparatus comprising, in combination, a

closed receptacle defining a chamber and having spaced opening means each placing said chamber in communication with the exterior thereof; conditioning means having inlet and outlet means and including a blower, a heater and a moisture extractor in cascade connection, with said heater being nearer to said outlet means than said moisture extractor, for moving a gaseous drying medium from said inlet means to said outlet means while at least partially extracting moisture from the. gaseous medium, thereby at least partly drying the same, and thereafter heating the thus-dried gaseous medium; connecting means in communication with said opening means of said receptacle and with said inlet and outlet means of said conditioning means for placing said receptacle and said conditioning means in closed circuit communication with each other, said connecting means being movable between a first position wherein said inlet means of said conditioning means is in communication with one of said opening means of said receptacle and wherein said outlet means of said conditioning means is in communication with the other of said opening means of said receptacle, and a second position wherein said inlet means is in communication with said other opening means and wherein said outlet means is in communication with said one opening means; temperature-responsive operating means located at said inlet means of said conditioning means and connected to said connecting means for moving the same between its first and second positions in response to the temperature of a gaseous medium entering said conditioning means, whereby an at least partly dried and heated gaseous drying medium may be passed through said receptacle in a direction which is dependent upon the temperature of the gaseous -medium entering said conditioning means, thereby drying a material within said chamber of said receptacle; manually operable vent means in communication with said receptacle for placing the same, and consequently the closed circuit formed by said receptacle, said conditioning means, and said connecting means, in communication with atmosphere, whereby said receptacle, and consequently said closed circuit may, whenever desired, be vented manually; and manually operable valve means located at said inlet and outlet means of said conditioning means for opening and closing the same,

whereby said receptacle and said conditioning means 13 may, if desired, be placed out of communication with 5,2 each other manually. 2,722,057

References Cited in the file of this patent UNITED STATES PATENTS 5 231?: 2,101,461 Steinen Dec. 7, 1937 2,347,601 Jackson Apr. 25, 1944 2,520,871 Wright Aug. 29, 1950 14 Hc'megger May 6, 1952 Pugh Nov. 1, 1955 FOREIGN PATENTS France July 6, 1910 Germany June 18, 1925 OTHER REFERENCES Carrier Eng. Corp., Drying and Processing, 1929.