US1435152A - Drying means - Google Patents

Description

C. H. CURRIER.

DRYING MEANS.

APPLICATION FILED FEB. 2, 1920.

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Patented Nov. M, 1922.

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A TOHNEY C. H. CURRIER.

DRYING MEANS.

APPLICATION FILED FEB. 2, 1920.

Patented Nov. M, 1922.

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maaier cams H. CUBRIER, or CHICAGO; ILLINOIS, Aiss'IGNoR To Darme SYSTEMS, me.,

OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS DRYING MEANS.

application med February 2, 1920. serial No. 355,673.

To all 'wlwmz'tmay concern: e Be itv known that I, CHARLES H. CURBI'ER, a citizen of the United States of America, and a resident of Chica-go, county of Cook, and State of Illinois, have invented certain new and useful Improvements in Drying Means, of which the following is a specification. Y This invention relates to methods and i@ means adaptedy for use Vin drying siccative coatings, as for instance, in drying-room installations for finishing automobile bodies, furniture, cabinets, and the like, for which purpose itais desirable to treat the air to be used respecting' its temperature, humidity,

and purity.

Heretofore, attempering or conditioning devices have been installed for washing, hu*- midifying and adjusting the temperature of 2e the air in drying rooms for paint,fx varnish,

and the like, for instance as set forth in my Patent No. 1,230,282, dated June 19, 1917, and separate drying rooms have been Sprovided having dii'erent atmospheric conditions corresponding With'the several stages generally recognized in the'drying process, namely the solvent evaporatingv stage, the oil oxidizing stage, and the hard drying stage.

The main objects of this invention are to '30 provide an improved process and corresponding means for drying siccative' coat- Lings, particularly finishing coatsv of varnish; to provide Successive stages in a continuous drying process whereby the object to be treated may be advanced from one stage to another, in which the atmospheric conditions respecting temperature and relativehumidity correspond with the degree of dryness and hardness of the coating; to provide such do a System adapted for operation and use all in one room and includin a. common attempering unit; to provide or improved distribution of the air including cross circulation,'and to provide for a final cooling treateo'ment with correspondingly attempered air beforend-ischarge from the dryingroomnto provide in a pluristage dryingroom means- .of improved form for circulating the air and distributing same etliectually to accom- 5@ plish the ^purpose stated; to`provide distributed step-by-'step attempering means adapted to efect the desired result; to pro- -vide for advancing a number of lines of units to be driedfdirectly from `the point of applying the coatings into and through the drying room in parallel relation to and independent of one another; and to provide automatic means for maintaining the desired conditions at ta predetermined graded standard throughou 4 4An illustrative embodiment of this invention is shown in the accompanying drawings, in which Fig. l is a plan of an installation including the essential features of the invention, the view being on a horizontal section at 1-1 of F1g. 2, and the roof of the drying room being removed. l

-F ig. 2 is a vertical section 1 and 3, with the front end of the drying room removed.

Fig. 3 is an enlarged vertical section at wall and doors ,3`3 Von Fig. l.

sive. fluid pressure motor or diaphragm vallve system for automatic attempering contro In the construction shown in the drawings the pluristage drying room l is built into a larger building or workroom 2 with provii sion`v adjacent to the ends of the drying room at 2 2 onFigs.

for installation of the attempering apparatuses 3, such as illustrated at the right end A of Fig. 1.

The device 3 here shown includes air wash ing, heating and humidifying means, namely,

the preheater 4, thev air s raying Washer and humidifier 5, andthe re eater 6. Adjacent thereto' are -ow-pans 7, drip-pans 8, and' means for distributing the objects to be coated for parallel entry into the drying, room,'namely,. a transverse runway or dis! tributing space 9.

The drying room as a Whole is'relatively long and narrow with a number of parallel runways or tracks '10 extending lengthwise thereof for 'simultaneous transmission of several lines of the coated objects 11 through the drying room. As here shown there are ten ways which may be regarded as constituting groups A and B of five ways each for the two pans 7 respectively.

A pair of air conduits 12 ,and 13 extend lengthwise of the drying room, except adja-` Y for discharge to a greater or less extent into the open air, as provided forl at ventilator 14 at the outlet end of the collecting main 13.

The conduit 12 which supplies the treated air for the main bodyfof the drying room is disposed in the upper part of the workroom 2, preferably over the center of the drying room and close to the roof 1 thereof. It comprises a plurality of sections or stages, for example 15, 16, and-17, corresponding -with the several progressive temperatures desired, with auxiliary heating means or boosters 18 at the junction points where successive stages meet. These temperature boosters 18. include steam coils or the like, substantially as used in the heaters 4 and 6, as will be understood, though not shown in detail. The relative humidity is decreased by said boosters as the temperature is raised. Each state is provided with a set of branch discharge conduits. 19 extending crosswise of the room in opposite directions, and each having one or more arms 19 extending downward through ceiling 1 and adjacent to the floor, where upwardly turned discharge nozzles 20 are provided adapted to direct the treated air diagonally upwardly and backward crosswise' against the coated ob jects 11, and toward the return conduit 13. Said supply conduit isdiminished in size as at the points21 between successive branching points, so as to compensate for the dimlnishing air load an'thus assure and maintain a uniform pressure for the discharge nozzles 20 throughout the length of the con-V duit. The branches 19 are all of substantially the same size and character, except that the branches having more than one downward arm are somewhat larger than the others, and are reduced at the arm, branching points, as at 19". Part of the arms 19 are largely hidden behind the pillars 2 Which support the roof 2".

Heatfis so a plied to the attempered air that a. relative y slight rise in temperature is provided for the first stage; a somewhat higher temperature is provided for the second stage; and so on, except that in the last stage the temperature is much lower, being preferably about the same as in the first and is preferably near one side of the drying room. `It is provided with a series of branches or arms 22'extending through said ceiling and downward adjacent to the floor where the ports 23 are provided for collecting the.cooled and vitiated aifr in the lower part of the room. Said return conduit is somewhat similar to the supply conduit respecting its adaptability to maintain a substantially uniform air pressure, sub-normal for suction, throughout its length. The pressure is negativerather than positive, as the return conduit is subject to the suction of the blower, tending to cause a vacuum wherebythe air is driven into the conduit. For this purpose the size of the conduit is increased between the successive branching points 24 in the direction extending toward the airtreating means 3.

The ventilator 14 in conduit 13 near the attemperer 3 is provided with a vent ue 25 and an intake flue 26, said iiues, together with the main flue at this point, being provided with valves or dampers 27, 28, and 29 respectively, adapted to cause discharge of the collected air outside of the building and replacement thereof by fresh air, or the air may be all returned .to the air-treating means, or if desired, the said valves may be adjusted intermediately in such manner as to provide for artial exchange and partial re-treatment ofp the air, as will be readily understood by reference to the drawirgs.

In this connection, see also my Patent 1,230,282. These valves may be thermostatically controlled as are the three similar valves shown in Fig. 4 and hereinafter described.

The' distributing nozzles 20 are provided' with dampers 30 adapted for adjustment -for any desired capacityf Similarly, the collectingports 23 are provided with adjustable dampers 30'. .A

In order to properly, completethe drying process so as to insure a hard and durable flawless finish, means are provided in the Ifinishing section or final stage for applying relatively cool moist air to the goods 11. For this purpose supply and return means 31' and 32 are furnished which are independent of the similar air-carrying means above described. To this end the supply conduit 31, which may be placed under the Hoor. is provided with two branches 33 and 34 disclosed crosswise of the drying room in spaced relation lengthwise of the room. Each of these branches diminish s in size step by step as at 35 between the outlet nozzles 36, toward the extremities remote from the source. The return conduit 32 is in the vupper part of the dryingroom and is disposed transversely of the room: It is provided with a series of intake means 37. This ner as described in connection with the corresponding apparatus at theo opposite end of the room. The attempering meansjor this Y supplemental or finishingl step may to advantage be more or less combined with the main attemperer (Fig. 7 as will be understood, thoughab'ove' explained as a separate means.

Automatic control of the temperature of the air at the several .points indicated is effected by means of adjustable thermostats operatively connected to the heating means through the medium of fluid' pressure motors. 4

.Such atmospherieally respnsive control means are shown in the fragmentary diagram of Fig. 8. The thermostatically controlled air pressure motors 45, 46, 47, 48, and

49, having valves connected therewith as uiiderstood in the art, regulatethe passage of steam from the supply main--50 to the pre- .f

heater 4f reheater 6, and the three boosters 18 respectively. The motor 51 is hygrometrically responsive to the degree of humidity of the air leaving the reheater 6 and serves to supply humidifying .steam thereto ifArequired in order to obtain the desired moisture.

vThe compressed -aiir for operating the motors 45 et cetera, is supplied through the air main 52 leading to the air tank 53 adjacent to thecontrol operators panel 54.

The art of automatic control of the atrn'osphere by means which are responsive to changes in temperature or humidity or both is already well understood and full explained in the published art. Hence, will merely refer to certain United States patents showing atmospherically responsive means` directly operate the steam valve, substantially as may be used in my drying room equipment. The Johnson P atent No. 542,733 shows a heat regulating apparatus, also using` air motors to operate steam valves. he drying roomproper is preferably arranged, for the sake'of efliciency and economy, with its ceiling l little more than high enough to clear the objects 11 to be treated, and it is for this reason that the distributing and Ventilating conduits are,

disposed in the space above the drying-room roof. i

Referring to the air-treating equipment, it is to `be understood that same may beV of any of the various well-known forms adapted to effect the desired treatment. The preheating member. the combined air-washer and humidifier, the reheating member, and the fan 55 and the motor 56 for operating same may be variously designed to fit specific needs.

The return flue amd ventilator valves'42, 43, and 44, see Fig.`4, may to advantage be operatively connected mechanically to one another andto a thermostat 57, responsive to temperature changes "in said flue, whereby control of the gradual replacement of used air by cool outside air may be effected automatically in a manner to maintain any desired temperature at the point where the thermostat is located. The valvesl 27, 28, and 29 at ventilator 14 may be controlled in similar manner. Y

The operation of the drying room and associated apparatus is as follows: The goods to be treated, for instance, automobile bodies, having been sprayed or otherwise ycoatedwith varnish at theflow pans, and having stood sufiiciently over the drip pans to eliminate all surplus varnish, are moved forward from-the drip pans and distributed'transversely in the cross space at the front end of the dryer room and distributed ,to the several runways or lines 10. The goods are carried preferably about 28" from the floor, either on trucks or other suitable conveyers, not shown, as will be understood. The goods are permitted to rel main a s'ufiicient length of time inthe firststage to partly dry the varnish, whereupon they are moved forward successively 'through the remaining stages. AThis movement may be either slow andcontinuous or the goods may bee advanced in batches priodically.

In the next to the-laststage, the varnish drying is completed, whereupon the goods are delivered tothe final or cooling stage', where the varnish is subjected to relatively cool -moist air, whereby it`is acclimated for subsequent exposure to the outer air, without danger of developingfine cracks whichresult from sudden changes of temperature, and whereby it is made ready to' be immediv jured by contact with workmens hands.

ately handled without danger of being inllore specifically, in the first stage, Where the temperature is moderate, the solvents and thinners are evaporated from the varnish and the work as a whole is heated up Without causing any case hardening or the formation of a surface film. The temperature in this stage may be held at about 100 F. dry ,bulb and 86o wet bulb. corresponding to a relative humidity of 56% and with a moisture content of 11.07 grains per cubic foot. In the second stage the oils in the varnish are oxidized, so as to put the varnish in a sufficiently dry state to remove all trace of tackiness and to get the entire coat uniformly dry. This stage may be held at about 108O dry bulb and 88o wet bulb, corresponding to a relative humidity of 45% and a moisture content of 11.12 grains per cubic foot.

In the third stage the varnish is sufliciently dried down and hardened so that the object may be handled safely when cooled. ,Here the dry bulb may be maintained at 120o and the wet bulb at 90, which corresponds to a relative humidity of 31% and moisture content of 10.73 grains per cubic foot.

In the last. stage, which in this instance is the fourth, the coating is subjected to an appropriately conditioned cooling atmos-l phere, where the varnish is acclimated for exposure to the outer air. Here the temperature may be 80o F. and therelative humidity 90%.

The operation of the air attempering and distributing apparatus is substantially automatic when once adjusted and set into operation. The air of the drying room is circulated through the attempering means 3 and distributed in .the manner above described, the rate of flow and the gradual renewal of the air through the ventilators being controlled by atmospherically responsive means/adjusted manually from time to time to maintain the precise conditions desired. The automatic temperature control means 4, 6, and .18, as well as the moisture controlling means, may also be adjusted from time to time as may be required.

In ordei` to insure a substantially uniform condition of the air adjacent to the ends and to enhance the efficiency of the device, movable closure means 58 and 59 are provided at the entrance and discharge ends of the drying room. Said means may be providedl in various ways, as for instance swinging doors or curtains may be used,l as understood in theart.

' As a result of this unified pluristage proccess, the product is'uniform and dependable to a degree not practicable to obtain commercially with devices heretofore known, and the efficiency of the plant and labor elements of production are greatly increased.

Although but two specific embodiments of this invention are herein shown and described, it is to be understood that'some of the details of the methods and .devices set forth may be altered or omitted without departing from the` spirit of this invention as defined by the following claims.

I claim:

1. A system of the character described, comprising a common drying room `adapted for the progressive movement therethrough of objects to be dried, means adapted to distribute a supply of air and to locally circulate same in successive parts of said room, and a pluralityof air attempering means adapted and arranged in progressive order to effect nearly uniformgraduated adjustment of atmospheric `conditions along the path of said objects, so as to closely approach the best drying conditions for successive stages of the drying process.

2. A pluristage drying room provided with an air distributing main extending therethrough, having attempering boosters positioned along its length and air outlets between said boosters.

3. A pluristage drying room provided' with an air distributing main having at-r tempering boosters positioned along its length, atmospherically responsive means operatively associated with each of said boosters to automatically control their several effects in accordance with predetermined atmospheric conditions for the corresponding stages, and air outlets between said boosters. i

.4. A pluristage drying room having means to provide atmospheric conditions of upwardly progressive temperature in the first stages and a diminution of temperature in the final stage.4

5. A pluristage drying room having means to provide atmospheric conditions of upwardly progressive temperature in the first sta es and a diminution of temperature in t e final stage, means being provided adapted and arranged to preheat the air supply, means to wash the heated air, and means for heating different parts of the air going to the initial stages and-the finishing stage respectively to different degrees re' in the return main adapted to permit of partial renewal of the air to a greater or less extent during the operation of the device.

'7. A drying room having successive stages merging one into another in which the atmospheric conditions are serially adapted to effect substantially the following results respectively on siccative coatings, first, drying out of the solvmts and thinners, second. oxidizing of the oils. and third, drying 10 down and hardening the coating, 'the successive stages being adjusted for increasing temperature and decreasing relative humidity.

Signed at Chicago this ninetenth day of 16 January 1920.

CHARLES H. CURB-IER.

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