US1912784A - Rotary adsorber unit - Google Patents

Description

June 6, 1933.

E; B. MILLER ETQAL ROTARY ADSORBER UNIT 4 Sheets-She et 1 Filed March 31, 1931 June 6, 1933. E. B. MILLER El l. I r 1,912,784

ROTARY ABSORBER UNIT Filed March 31, 1931 4 Sheets-Sheet 2 Fan June 6, 1933. E. B. MILLER ET AL ,9

ROTARY ADS ORBER UNIT Filed March 31, 1931 4 Sheets-Sheet 3 249 v Z05 gwvmliow' M g M :3 fr Kg,

Patented June 6, 1933 .U reo- STATES. PATENT OFFICE ERNEST B. MILLER AND IBAYARD P. FOIDA, 0F BALTIMORE, MARYLAND, ASSIGNOBS ,TO THE SILICA GEL CORPORATION, OF BALTIMORE, MARYLAND, A CORPORATION OF HARYLAN D ROTARY ABSORBER UNIT This invention relates to adsorption systems and adsorbers, and more partlcularly to such systems and apparatus for continuousadsorption, using that type of adsorbent materialwhich can be reactivated or revivified by heating.

It'is a general object of the present invention toprovide a novel and improved adsorption system and apparatus therefor.

More particularly itis an object of the invention to provide an adsorption process and apparatus therefor wherein continuous operation is effected and in which cooling is provided for the treated gas during its pasgle adsorber unit and sage through the adsorbent,

'One of the important features of the invention consists in the provision of an adsorber unit of the type above described which is readily capable of use singly or in a battery by merely multiplying the unitsand providing appropriate duct systems. This provides a flexible system which can be enlarged as demands increase, without any rebuilding.

Another important feature of the inven-' tion resides in the construction and arrangement of the rotar .adsorber unit and its mountings and gas oods, ducts, etc.

Still another important feature of the system resides in the novel construction and arrangement of the cooling means used for maintaining a .low temperaturein the treated gases during adsorption.

A further feature of the invention resides in the construction and arrangement of the novel distributing valve for use: in directing the cooling fluid through various portions of the adsorber unit.

Other and further features and objects of the invention will be more apparent to those skilled in the art upon conslderation of the accompanying drawings and following specification wherein have been disclosed several exemplary embodiments of the invention as well as illustrations of its application. It

5 will of course, be understood that such changes and variations, including the substitution of parts from one form in another, such as fall within the scope of the appended claims, may be resorted to without departing from the spirit of the invention.

' a portion of the casing broken away to illustrate the rotor construction; i Figure 2 is a transverse or axial section taken on'broken line 2-2 of Figure 1;

Figure 3-is a partial section taken on line 3-3 of Figure 1; Figure 4 is an elevation of the outer face of one member of the distributing valve;

Figure 5 is a similar view of the inner or operatingface of thevalve member;

Figure 6 isa schematic showing'of a sinits operating appurtenances; Figure 7 is a vertical section, taken in the axial. direction, ofia modified form of adsorber unit; I

Figure 8 is an elevation of one form of hood arranged for a-dsorberunits of the typepreviously shown;

Figure 9 is a plan view of a plurality of adsorber units arranged in axial alignment for multiple operation and showing the associated duct systems, filters, fans, and activating furnace; a

Figure 10 is a side elevation of the apparatus of Figure 9; and i Figure 11 is a side elevation of the inner face of the ducts shown at the upper part of Figure 9 with the adsorber units removed. The present invention is chiefly concerned with adsorbers using, for instance, .a hard porous adsorbent of the nature of silica el. It is characteristic of such adsorbents t at they may readily adsorb certain constituents from a moving stream of, gaseous mixture and, when saturated with such constituent, can be renewed for reuse by heatin Such heating can conveniently be effected y passing hot combustion gases through the adsorbent material which is conveniently in granular form. It has usually been the practice to arrange theadsorbent material in stationary "beds in closed casings and supported on suitaccording to the present invention.

a system of dampers, suitable activating ases can be passed through the bed. This form of apparatus requires at least two adsorber beds, which are used for adsorption and activated alternately, and calls for a fairly complicated system of ducts and dampers or valves for controlling the various gases.

The present invention obviates these additional parts and permits a single bed of adsorbent material to be used continuously by the expedient of arranging it in the form of a solid of revolution, having screens on two surfaces of revolution, and passing this rotor by its rotation continuously through two chambers, one containing gases to be treated and the other containing activating gases.

By this arrangement, adsorption and activation are continuous, and all parts ofv the adsorbent are continuously in use. Activation can be done in the least possible time without regard to the rest of the cycle. The dehydration efiiciency of the adsorbent in the adsorption phase will not be uniform because at the intake into the adsorption chamber the material is fresh, and at the exit end it is saturated, but the over-all efficiency of the whole adsorption sector is uniform, and high saturation is obtainable. All temperature conditions are stable so far as the adsorption and activation chambers are concerned as a whole. The activation gas exit temperature is different for the different parts of the activation sector, but the exit temperature of the mixture is constant.

Referring now to the drawings for a further understanding of the invention, there will be found in Figures 1, 2, and 3 the main features of a single unit adsorber COHStIIK IItAIBId e adsorbent container or adsorber proper is in this case in the form of a figure of revolution and preferably a flat disc 10, the sides 11 of which are conveniently formed of suitable foraminous metal, such as bronze screen, and the peripheral border 12 of a suitable ring of solid metal sheet. The two screens are supported on and secured to the flanges 13 and 14 of a hub 15 secured to the shaft 16 journaledin suitable bearings 17 carried on the supporting standards 18.

The two screens are maintained properly spaced and are rigidly supported by the radial partitions 20, shown on an enlarged scale in Figure 3 as being of channel form and having the flanges 21 to which the screens 11 are secured as by soldering, brazing, or spot welding. These radial webs 20 extend from the hub to the peripheral band and are secured to both in an air-tight manner whereby they divide the adsorbent basket into a plurality of sectors which are open only through the screens onto the two faces of the disc. These sectors are filled with granular adsorbent material through suitiable filler openings.

In operation the air or gas to be treated, and from which one or more constituents are to be adsorbed by the adsorbent in the sectors, is passed in an axial direction through a number of the sectors simultaneously while the rotor is slowly rotating.- In accordance with Figure 1, the portion of the adsorbent basket or cage which is at the time at the left, and comprising substantially 180 thereof, is used for adsorption, and for that purpose there is applied against each face of the rotor a; hood, that on one side being numbered 23 and that on the other 24. These hoods have substantially air-tight engagement with the inner and outer peripheries of the rotor screens by arrangements which will be more fully described later, and they have engagement with the radial edges of seals which bear on the surfaces of the screens to limit the extentof arc of the rotor to which the gases in these hoods aresubjected, Each hood is provided with suitable inlet or outlet ports 25--26 for connection to L gases is to be effected. If cooling is to be.

pgssive and by radiation only, the hoods will substantially flat and without entrance and exit ports.

For purposes of convenience in the following specification the invention will h e described as if the system and apparatus were used for the purpose of dehydrating atmospheric air such as for conditioning the air for buildings, blast furnaces, or the like, but it will be understood that the invention is in no'sense so limited in its application.

In order to separate the inlet compartments formed by the hoods 23, 28, and 29 on one side of the rotor and the outlet compartments formed by the corresponding hoods on the other side, a seal is provided between each two compartments. Such seals are seen in elevation at 30, 31, and 32 in Figure 1, and one is shown in section in Figure 2. The seal proper comprises a sector 34 .of some suitable metal, such for instance as phosphor-bronze, which bears directly on the surface of the screen material 11 and is held in contact therewith by means of spring-backed plungers 35 received in tubes 36 having caps 37 thereon form adjusting the tension of the springs. These tubes 36 are carried by a plate 38, and there is provided a connection betweeneach seal plate compartment and the 7 through the adsorbent and issuing into another.

All of the hoods and seals on each side of the rotor are formed into a unitary structure by inner and outer bands 40 and 40, respectively. The outer band 40' is reinforced by angles 41 and 42. The angles 41 of the two hood and seal units. are secured together by straps 43 straddling the edge of the rotor. These straps hold the units together and against the sidesof the rotor. A circumferential ring or angle bar 44 of anti-friction material bears on each reinforced radial periphery 45 of the rotor under the action of the springs 46 arranged between it and the angle bar 41 and forms a seal against radial leakage of air from the hoods and seals. Equivalent structures are indicated at 47 at the inner edges of the screens 11 and function in the same-manner and for the same purpose. It will be appreciated that the type of seal, at the edges of the screen and between the hoods, is more or less immaterial insofar as the broad features of the invention are concerned, and any mechanism which 'Will insure substantial air-tightness with minimum friction at these places will be satisfactory for the purpose.

It is well-known that adsorbent material, on taking up vapors or gases, rises in temperature due to what is known as the heat of adsorption. It is further known that most adsorbentmaterials function much more effectively if the temperature is maintained low, and for this purpose means is preferably provided for removing the heat of adsorption from the adsorber and/or cooling the air on passage therethrough. In Figures 1 to 6, inclusive, this is done by embedding cooling coils in each of the sectors of the rotor, and preferably these cooling coils are of the finned type.

As seen in Figures 1 and 2, each cooling coil. 50 preferably comprises a singleloop or bight starting from the inner periphery of the screen and running radially outwardly near one screen, as at 51, and returning near the other screen, as at 52. As shown,'the twovparts of the loop may be connected t gethcr by a series of thin metal plates or fins 53 which may extend for substantially the full width of the sectors in orderto insure the removal of heat from substantially all of the adsorbent material and to provide contact with most of the air passing therethrough. The direction of the planes of the fins is such,however, that they do not interfere with the flow of gases in an axial direction through the rotor.

The hub of the rotor-has its larger flange 13 provided with the thickened peripheral portion 55 into which the ends of the cooling tubes 50 are inserted by bending them at right angles, as shown at 56, and securing them in the holes 57 and 58. These two holes lie in the same radial plane. It will be seen that I the outer face of the part 55 then will be provided with two concentric rows of holes leading to the pipe loops and that each row will have the same number of holes, the holes belonging to the same loop-lying along the same radial plane.

To conduct a cooling fluid, such for instance as' water, to these pipes in the proper order, a disc 60 is loosely mounted on the shaft 16 and maintained with its radial face in and the other with the inner ring of holes 58 in the valve member 55 movable with the rotor.

. A port 67 is provided through the disc 60 and is connected with a suitable source of cooling fluid, for instance cold water, and this port, as seen in Figure 5, enters the inner circumferential groove 66 to supply water thereto. Both grooves adjacent this port 67 are provided with the stops or closures 68 and 69 so that, as viewed in Figure 5, the water cannot flow to the left from the port 67. It enters the groove 66 and flows through all of the pipe loops which connect with that portionof the groove lying between the stop 69 and the stop 7 0 so that several sectors have the water flowing therethrough in parallel. The water delivered from these sectors is received in the groove 65 and then flows into the outer holes 57 leading to pipes in the ad jacent sectors, as far as permitted by the stop 71, and this water is discharged into the inmen groove between the stops 70 and 72 and again returns to the outergroove between the stops 71 and 73. This performance is repeated as far as the stop 75. This provides Before considering further the action of the valve members,it may be well to briefly outline the modeof operation of the device. It will be described in'connection with the dehydration of air since this forms a simple and convenient example. The air to be dehydrated is conducted into the hood 23 and flows through the sectors corresponding to approximately 180 of the rotor wherein the moisture is adsorbed and the stripped air delivered into the hood 24 and out through the duct 26. The rotor continues to be rotated slowly by suitable drive means acting on the gear 80 so that fresh sectors are continually brought beneath the adsorption hoods, and sectors having the adsorbent saturated with moisture are brought into the activating section. In this section heated gases, such as may result from the combustion of fuel gas, are forced from one hood to the other through theadsorbent material to drive out the moisture. In Figure 1 this would mean a rotation in a clockwise direction.

Leaving the activating sector, the material is brought into the cooling sector where some of the heat-of activation is removed. Entering the adsorbing sector as the rotation continues, the still warm sectors are subjected to the cool entering air and further cooled so that they progressively increase in adsorption quality as they proceed into the adsorption portion of the apparatus. After they have been in this portion for a time, however, they become partially saturated, and their eifectiveness begins to recede, and they must be kept cooler and cooler in order to take up the necessary quantity of moisture from the air passing through them.. It will be seen that the cooling fluid valve is arranged to provide maximum cooling for the sectors which are about to leave the adsorption phase, for the cold water enters them first and is progressively heated as it passes from the multiple grouping of cool .ing units of the sectors on its way to the stop 75.

From the stop 75 the water circulates, in the manner just described in connection with the adsorbing phase, through thecooling sector until it reaches the stop 81 and leaves the inner groove 66 through the port 82. During the passage through this 60 of arc, the water, which has previously been somewhat heated, receives much more heat in partially cooling down the adsorbent material which has just left the heated activating zone, and this hot water is. made use of to initially warm up the adsorbent material which leaves the adsorption zone and moves into the activating zone, so it is conducted by the pipe 83 into the port 84 which is just on the opposite side of the stop 69 fromthe cold water inlet port 67.

From the port 84 the'water enters the inner groove 65, and water flows between the stop 69 a ndthe stop 85 and is delivered into all of the coils which cooperatewith this portion of the groove and discharged by them into the outer channel between the stops 68 and 86 and then returned by other loops to the inner channel between the stops 85 and 87 and discharged through the outlet port 88. This water, which has received the heat of adsorption and the heat of cooling from the previously heated adsorbent material, is instrumental in preliminarily heatin up the adsorbent material about to be activated and assists materially in con'-' serving heat and reducing the expense of activating.

I Water which remains in the cooling coils which are moving from the sectorincluded between thestops69 and 87 is permitted to drain from both legs of the coil by gravity into the two channels and is discharged by gravity out of them respectively through the ports 89 and 90. These ports 89 and 90 are connected on the outer face of the valve disk by means of a pipe 91, and this pipe 91 is connected by a pipe 92 to the port 88 and to the common discharge pipe 93 which carries away all of the cooling water from the valve. -It will be clear that a flexible connection, such as a hose. will be attached to the pipe 93 as well as the pipe 94 leading to the inlet port 67.

It will be seen that, if the valve disc 60 were maintained stationary while the rotor moved steadily, there would be times when the stops in the channels would completely close off openings into the various coils and would at other times seriously throttle these openings, so it is found more desirable to permit the disc 60 to rotate in unison with -the disc 55 on the rotor for an arcuate distance equivalent to one sector and to then snap the disc 60 back to its initial position to repeat the operation. Since it is loosely mounted on the shaft, this can be elfected as follows:

The shaft carries permanently secured thereto a ratchet wheel 95 having the same number of teeth as there are sectors in the rotor. Pivoted at 96 onthe disc 60 is a dog 97 having the portion 98 which engages the teeth of the ratchet 95 so that, as is seen in Figure 4, as the ratchet rotates in a clockwise direction, the plate 60 is constrained to move therewith, tensioning the spring 99 secured between the screw 100 on the disc and an arm 101 carried on the stationary bracket 102 which is suitably connected to the support 18 for the rotor. Also carried by this bracket 102 is the arm 103 having thereon the pins 104 and 105 adapted to cooperate with the tail 106 of the dog 97. hen the disc 60 has moved from its initial position to a position removed therefrom an arcuate distance equivalent to the width of a sector, this tail 106 engages the pin 104 to release the dog from the ratchet to permit the disc 60 to be returned to its initial posi-v a convenient way of arranging a single adsorber unit for air conditioning. The air to be treated enters the filter 110, which re-' moves mechanical impurities therefrom to protect the adsorbent material, and is delivered to the fan 111' which places it under sufficient pressure to deliverit into the ducts 112 and 113. The duct 112 may connect to the hood 23 to pass air therethrough for dehydration, and the dried air is delivered into the hood 24 and out of the duct 26. A portion of the-air from the fan enters the duct 113 and may provide the primary and secondary air in a gas furnace 114. Any other way of heating the air, such as by steam coils or by the combustion of coal, oil, or the like, may be sorbent material, a similar result can be effected by providing two spaced rotors with suitable cooling means between them, and such a construction is shown in Figure 7. Here the construction, not otherwise described as different, is identical with that in the first five figures of the drawing. There are, however, two rotors 200 and 201 spaced apart a slight distance and mounted on the same shaft. They cooperate with hoods and seals both on the outsides and between the rotors in the same manner as described in connection with the preferred embodiment.

In the space between the adsorbers can be arranged cooling coils or pipes 202 which are of course, stationary and eliminate the need 0 valves and similar mechanism. The coils can be -disposed to provide the same type of cooling and heating as is done b the valve mechanism in the preferred modi cation, for these coils can firstconduct water between the adsorbers where they are on the adsorption phase, then between them where they are on the cooling phase, and finally for preheating during activation. During the actual heating by the activating gases, there is no need for conditioning by the cooling fluid so that pipes can be omitted in these sectors. It will be appreciated that various mechanical features can be applied to the construction of Figure which need not form any part of the present invention in order that it may successfully function from a mechanical standpoint. I

In Figure 8 is shown a side elevation of an adsorber unit in which the hoods have been arranged for two-stage adsorption. In such an arrangement the air will first be passed into the hood 205 and, on leaving with its tem- I perature raised from the heat of adsorption, can be passed'through 'a suitable inter-cooler, if desired, to again lower its temperature, and it is then returned either to the hood 206 or tothe corresponding hood on the other side if this makes for more convenient piping. This second stage of adsorption preferably takes place in adsorbent material which has just freshly been activated, so that it will be seen that the rotor in this arrangement should move in a clockwise direction, so that the most saturated adsorbent leaving the adsorbing section beneath the hood 205 will enter be: neath the hood 207, where the activating gases are conducted to it.

There may be provided a cooling sector 208 in which the cooling is effected either-by the cooling coils within the adsorbent orby efi'ecting a closed circuit between the hood 209 and the corresponding hood on the other side,

a fan, and an indirect cooler whereby a continuous circulation ofthe same air can beeffected for cooling the adsorber. In a good many cases, however, the cooling sector can be entirely omitted. That is particularly true in a two-stage adsorption unit, for the sorbent entering for the second stage of adsorption, and in this way a greater extent of adsorbent can be used for the actual adsorption.

In the various forms previously described, it will be seen that the adsorbent can be put to maximum effectiveness and a lesser quantity used than in the stationary types of bed adsorbers. Furthermore, the rate of adsorp-.

tion can be changed in accordance with the degree of saturation of the material to be treated by varying the speed of rotation and damping or advancing the rate of heating of the. activating fluid.

Where more capacity is desired than can be effected conveniently with a normal size single unit as just described, these units'can be conveniently arranged in batteries or gangs by placing'all of the. rotors on a single shaft 300, such as shown in Figure 9. .In this figure the rectangles 301 are considered to .be not only the rotors but their hood structures of units such as previously described. These hood structures are connected to large manifolding ducts so that all adsorber units 301 are connected in parallel.

In Figures 9, 10, and 11, the air filter302 is common to all 'adsorbers, and the air from it is placed under pressure by the fan 303 and delivered into the lower duct 304 having the branches 305 which connect to the proper inlet activation hoods on the adsorber units 301. The manifold. 306 is connected by the branches 307 to the outlet adsorption hoods on the separate units 301 and delivers into a suitable chamber 308 from which the air is delivered for use.

.On the opposite side the manifold 310 is connected by the branches 311 to the inlet activating hoods and provides heated gases from the furnace 312 for activating all of the adsorber sectors on that phase, in unison. The products of adsorption are withdrawn into the manifold 313 through the branches 314 connected to appropriate hoods on the units by the fan 315 which draws the combustion products through the adsorbent sectors and ejects them through a suitable stack 316. Any suitable form of drive, such as the motor 317, may be used for rotating the shaft carrying all of the units.

It will be appreciated that when less capacity is required than that provided by all of the units, several of them can be cut out by hand dampers, if desired. It will be seen that this construction permits of a convenient and flexible arrangement which can be enlar ed or reduced as desired by the simple addition of sheet metal ducts and branches so that any desired capacity can be obtained, while simplifying the manufacture of the actual units by maintaining them in a single standardized size for convenient fabrication.

Where the word gas is used in the claims, it is intended to cover mixtures of gases and/or gases and vapors.

-Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is '1. In an adsorber for treating gases, in combination, a rotatable cage having a series of sector like compartments, adsorbent material in each compartment, means to rotate the cage so that each compartment is brought into adsorbing position and subsequently into activating position, a fluid conducting coil in into a each compartment, means todeliver a cooling fluid to the coils of the compartments in adsorbing position to take up the heat of adsorption therefrom and means to deliver the heatedfluid to assist in the activating.

2. In an adsorber. for treating gases, in

- combination, a rotatable cage having a series of sector like compartments, adsorbent material in each compartment, means to rotate the ca e so' that each compartment is brought dsorbing position and subsequently into activating position, a fluid conducting coil ineach compartment, means to deliver a cooling fluid successively to the coils of several compartments in adsorbing position to take heat of adsorption therefrom.

11 an adsorber for treatin gases, in

combination, a rotatable cage having a series of sector like compartments, adsorbent material in each compartment, means to rotate the cage so that each compartment is brought into adsorbing position and subsequently into activating position, a fluid conducting coil in each compartment, means to deliver a cool ing fluid tothe coils of the compartment in adsorbing position to take up the heat ofadsorption therefrom and means to dellver the heated fluid to coils of compartments filled with adsorbent having just undergone.

activating position, a fluid conducting coil in each compartment, means to deliver a cooling fluid to the coils of the compartments in adsorbing position to take up the heat of adsorption therefrom, means to deliver the heated fluid to coils of compartments just activated to further heat it and means to then deliver the hot fluid to coils of compartments being activated.

5.,In an adsorber for treating gases, in combination, a rotatable cage comprising a pair of spaced circular screens, a closed peripheral member securing said screen edges together, spacers for said screens dividing the space between them into a plurality of sectors, adsorbent material filling each sector,

a cooling fluid pipe in each sector, a valve like compartments, adsorbent material in each compartment, means to rotate the cage continuously to bring each compartment successively into adsorbing and activating positions, a fluid conducting pipe in each compartment, a valve member rotatable with said cage and having therein the ports of all said pipes, a second valve member cooperating with said first member and means in said second member to direct a cooling fluid to coils in sectors in adsorbing position.

7. In an adsorber, in combination, a rotatable cage having a series of separate sectorlike compartments, adsorbent material in each compartment, means to rotate the cage continuously to bring each compartment successively into adsorbing and activating positions, a fluid conducting pipe in each compartment, a valve member rotatable with said with said first member and means in said second member to direct a cooling fluid'in parallel to coils in some sectors in adsorbing position.

8. In an adsorber, in combination, a rotatable cage having a series of separate sector- 5 like compartments, adsorbent material in each compartment, means to rotate the cage 7 continuously to bring each compartment successively into adsorbing and activating positions, a fluid conducting pipe in each compartment, a valve member rotatable with said cage and having therein the ports of all said pipes, a second valve member cooperating with said first member, and means in said second member to direct a cooling fluid in multiple series to the coils of all sectors in adsorbing position.

9. In an adsorber, in combination, a rotatable cage having a series of separate sectorlike compartments, adsorbent material in each compartment, means to rotate the cage continuously to bring each compartment successively into adsorbing and activating positions, a fluid conducting pipe in each compartment, a valve member rotatable with said cage and having therein the ports of all said pipes, a second valve member cooperating with said first member, means in said second member to direct a cooling fluid in parallel to coils in some sectors in absorbing position, and means to periodicallymove said second member with said first member an arcuate distance at least equal toone compartment sector and to return it rapidly.

10. 'In an adsorber, in combination, a rotatable cage having a series of separate sector-like compartments, adsorbent material in each compartment, means to rotate the cage continuously to bring each compartment successively into adsorbing and activatingpositions, a fluid conducting pipe in each compartment, a valve member rotatable with said the thus heated fluid through the sectors just entering the activation section to preheat those sectors.

In testimony whereof We hereunto aflix our signatures. e

ERNEST B. MILLER. BAYARD P. .FONDA.

cage and having therein the ports of all said pipes, a second valve member cooperating with said first member, and means in. said second member to direct a cooling fluid sues cessively through sectors in the adsorbing portion in a direction opposite to the movement of the cage.

11. In an adsorber, in combination, a rotatable cage having a series of separate sector ike compartments, adsorbent material in each compartment, means to rotate'the cage continuously to bring each compartment successively into adsorbing, activating, and cooling positions, a fluid conducting pipe in each compartment, a valve member rotatable with said cage and having therein theports of all said pipes, a second valve member cooperating with said first member, and means in said second member to direct a cooling fluid through sectors in the adsorbing and then the cooling section in a direction opposite tothe movement of the cage.

12. In an adsorber, In combination, a ro- 65 tatable cage having a series of separate sec-

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