US2501487A - Apparatus for treating soap - Google Patents

Description

March 21, 1950 R. s. WHITMAN APPARATUS FOR mums SOAP 2 Sheets-Sheet 1 Filed Sept. 30, 1946 III! I IHHHHHHH I HI I March 21, 1950 R cs WHITMAN I 2,501,437

APrARATUS FOR TREATING SOAP Filed Sept. so, 1946 2 Sheets-Sheet 2 Z M w l/fllll/lllll llllll/ Patented- Mar. 2!, 1950 UNITED STATES PATENT OFFICE APPARATUS FOR TREATING SOAP Robert George Whitman, Valley Stream, N. Y., assignor to Colgate-Palmolive-Peet Company, Jersey, City, N. J a corporation of Delaware Application September 30, 1946, Serial No. 700,263

- 2 Claims. 1

The present invention relates to the aeration of hot, powdered surface active agents, particularly hot, spray-dried soap particles and powdered synthetic detergent material to cool the same for packaging, and to apparatus for eifecting such cooling.

The invention will be illustrated in connection with a detailed description of a method of treating soap particles, particularly hot, spray-dried soap particles, to cool the same while they are being caused to travel on a sloping, detention cooling bed towards packaging apparatus; however, it is not to be construed as limited thereto, for it is applicable to the treatment of other hot, powdered surface active agents as indicated above.

In the normal operation of a spray-drying operation to form spray-dried soap particles, the particles, as they are withdrawn from the bottom of the spray tower, are at a temperature of about 170 to 195 F. and have a moisture content of about 8 to 14%. These particles are not in a suitable condition for packaging, for generally if spray-dried soap particles are packaged at a temperature in excess of about 95 F., there is a strong tendency for masses of these particles to stick or cake together and form lumps. These lumps are undesirable because they interfere with the free flow of the particles from .the packages and because the lumps do not dissolve rapidly in water.

In accordance with the present invention, cooling of the hot soap particles withdrawn from a spray tower, is effected on a stationary, perforated, sloping detention bed or table down which the particles travel towards the packaging apparatus, their movement being aided by air, gas or other aeriform body. In the practice of the invention the hot particles are introduced at or near the top of the perforated sloping bed and air or other aeriform body is introduced through the perforations from beneath the bed into the mass of particles to aerate and cool the same. The air passes through the perforations in the bed, preferably in the general direction of the product discharge end of the bed and this air aids in carrying the particles down the bed towards the discharge end and cools them while while they are being so conveyed. The aerated mass of particles, in a substantially fluidized state,

are accumulated in that state to a substantial depth while still on the bed, thereby prolonging the time of contact of the soap particles with the cooling medium. As the aerated mass of soap particles passes from the bed towards the packaging apparatus, the air separates from the cooled iii particles and is vented or recovered and conditioned for re-use.

The soap particles when first introduced onto the sloping perforated bed may be at a temperature and have a moisture content as set forth above, or they may be either cooler or hotter and contain more or less moisture. In any event they are in a condition unsuitable for packaging.

The air or aeriform body which is brought in contact with the hot soap particles to aerate, convey and cool them should be of a temperature and relative humidity and in such quantity as to reduce the temperature of the soap particles to about 95 F. or below during the time that the soap particles are moved from the inlet to the discharge end of the sloping perforated bed, without substantially increasing the moisture content of the particles. The air used to obtain the necessary conveying and cooling of the hot soap particles may be ambient air or it may be air which has been conditioned bothas to temperature and moisture content.

When spray-dried organic detergent particles are contacted with air, their moisture content,

may increase, decrease or remain substantially unchanged depending upon the relative humidity of the air and the moisture content of the par-- ticles. The term equilibrium humidity" is used herein to mean that relative humidity of air which effects neither a substantial increase nor in contact. Over the range of moisture contents encountered in the present process, the equilibrium humidity is practically directly proportional to the moisture content of the soap particles, which are discharged from the spray tower with a moisture content within the range of about 8% to 14%, usually 10% to 12%. Soap particles, for example, having about 8% moisture are in equilibrium with air of 50% relative humidity at a dry bulb temperature of approximately 75 F., whereas soap particles having about 14% moisture are in equilibrium with air of 78% relative humidity at said dry bulb temperature. The relative humidity of the air used in the'process of the invention to cool and transport the organic detergent particles preferably does not ex= ceed the equilibrium humidity and advantageously is lower. By using air having a relative humidity below the equilibrium humidity, moisture is evaporated from the soap particles, thereby intensifying the cooling effect of contacting soap particles with air and permitting the use of less conditioned air, or of conditioned air of higher 3. temperature or an intermediate combination of both while obtaining the same cooling effect oi air at equilibrium humidity.

when the relative humidity of the cool air is higher than the equilibrium humidity for the soap, moisture from the air condenses on the soap particles and this condensation increases the temperature of the soap particles somewhat and to this extent defeats the object of contacting the particles with relatively cool air to cool the same. Generally, therefore, the relative humidity of the cooling air is not higher than the equilibrium humidity of air for soap of the moisture content being treated, as pointed out above.

During the period of contact of the hot soap particles with air to effect cooling it is essential that the particles be in a state of turbulence or agitation so as to insure intimate contact of the air with the entire surface of the particles being treated. This agitation, however, should not be so intense as to cause substantial breakage of the particles. In accordance with the present invention the agitation is brought about by the passage of air under pressure through a mass of the particles on the sloping perforated bed. The air aerates and cools these particles and places them in a. more or less fluidized condition and in that condition the particles are caused to travel toward the bottom of the sloping table, where they are accumulated to a substantial depth to prolong the time of contact between the soap particles and the air and thereby efiect greater cooling of the former. From this accumulated mass the soap particles are delivered to suitable apparatus for packaging.

By conveying the particles of soap downwardly on a sloping perforated bed in a substantially fluidized state and holding them in that state for a while in an accumulated mass before passing them on to the packaging apparatus, more enlcient cooling of the particles takes place. Additionally, the force of the air necessary to effect movement of the particles in the substantially fluidized state is not so great as to induce in the particles such a state of agitation and turbulence as to cause substantial breakage of the particles and the production of objectionable quantities of fines-I! The velocity of the air which is introduced into the mass of particles on the perforated sloping bed in accordance with the present invention may vary over a wide range, the minimum being that velocity which is just suflicient to provide intimate contact between the treating air and the individual particles of soap in them'ass, and to convey or to aid these particles in traveling down the sloping table. A flow of about 0.125 to about 0.25 cubic feet per second per square foot of bed area satisfactorily aerates a mass of soap particles in accordance with .the present invention. A practical maximum air flow is somewhat below that at which the. soap particles become air-borne and can be conveyed vertically. The

air velocity in accordance with the present inven- Fig. 3 is a horizontal-section taken substantially along the line 3-4 of Fig. 2, showing the perforated sloping coming bed, only some of the perforations being shown;

Fig. 4 is a vertical section taken substantially along the line 1-4 of Fi 2. to ow e interior of the cooling chamber from the discharge end;

Figs. 5, 6 and 7 are, respectively, sections taken along the lines 6-5, 6-6 and 1-4 of Fig. 3, to show details of the cooling bed;

Fig. 8 is a fragmentary view, corresponding to Fig. 2, of a modified form of cooling chamber; an

Fig. 9 is a vertical section taken substantially along the line 9-8 of Fig. 8.

The conveying and cooling mechanism of the present invention consists essentially of an elongated cooling chamber III, of substantially rectangular cross section, having a top wall H, a bottom wall [2, side walls l3 and I4, and end walls i5 and 16, in which a sloping perforated bed I! is installed. Hot spray-dried soap particles or similar granular material of not over 10 to 20 mesh, suitably 50 to mesh, or finer, are carried by air or other aeriform body on the bed from the feed end, which receives the soap particles falling through inlet hopper ill, to the discharge end. Perforated bed ll slopes downwardly from the feed end to the discharge end, the slope varying widely, as desired, say from about 20 to 45 degrees. The slope of the bed, which is preferably somewhat less than the slope at which free flow of the powdered material occurs, aids in the desired movement of the particles.

Perforated bed ll divides the cooling chamber into a lower air distributing compartment is and an upper plenum chamber 20. Air is brought into compartment l9 through line 2! which is in communication with a suitable blower or compressor (not shown). The air under pressure in the lower compartment is passes through the perforations or louver openings 22 in bed l1 and through the mass of soap particles which is formed on the bed as the soap is introduced into the cooling chamber through the inlet [8. The air passing into the mass of soap particles aerates the same and aids them in traveling down the sloping perforated bed. The air which passes through or rises from the mass of soap particles passes through plenum chamber 20 and out through outlet 23, along with any dust which may become entrained therein.

In the operation of the cooling chamber it is preferred to maintain the interior thereof at substantially atmospheric pressure and to accomplish this, soap inlet It may be in communication with the surrounding air. Outlet 23 may also be in communication with the surrounding air but it is preferred to have it communicate with a suitable exhaust system operating at some pressure lower than atmospheric. This exhaust system may include therein one or more conventional air separating cyclones or one or more dust bag collectors or a combination thereof so that the dust may be separated from the air.

Sloping perforated bed l1 consists of a plurality of angularly disposed louver plates 24, suitably of metal, which extend lengthwise of the cooling chamber across the width thereof. It may, however, consist of a single louver plate having an area substantially equal to the combined areas of the smaller plates shown. The smaller plates are preferred from the standpoint 7c of ease of handling. The louver plates have up- 8 struck portions or shelves throughout the area thereof which overlie the louver openings or air slots 22 which are formed by striking up portions of plates 24 to form the shelves. Air passes through the slots to aerate the soap particles on the bed and the aerated mass moves or flows down the bed on these shelves.

Louver plates 24 are supported on supports 26 which extend between side walls is and I l of cooling chamber l0, and on wall member 21, at the bottom of perforated bed it. This wall member forms an end closure wall 28 for the air distributing chamber is and. has a depending portion 29 which extends below the bottom of cooling chamber it. Depending portion 29 together with similar and adjacent portions 30, 3! and 32, which extend downwardly from end wall i8 and side walls is and It, respectively, form a depending cooled product discharge outlet chamber 88, within which is positioned the discharge hopper 3%. Discharge outlet SIi-may be inserted through an opening in a floor if it is desired to convey the cooled soap particles from one floor to another.

The assembly of louver plates 25' to form perforated bed ii is obvious. Thus, supports 26 may be secured to the side walls l3 and it so that when the plates are laid thereon the bed will have the desired slope.

The bottom edge of the bottom louver plate is inserted in a slot (Fig. 5) which is formed by sandwiching a relatively narrow strip 36, between an overlying relatively wider strip 3'8 and the top of wall 28. The top edge of the louver plate rests on the first support it and it extends into a slot 38 (Fig. 6) which is formed by sandwiching a relatively narrow strip 39, substantially centrally between a relatively wider overlying strip dil and support 26. Strips 39 and Gil are maintained in proper position on support 26 as by nails 4i or by other suitable fastenin devices.

By assembling strip 39 substantially centrally both of strip Ml and of the top of support 26 slots are formed on either side of the central strip 39, slot 38 being the lower one and slot M the upper one. The bottom of the next succeeding louver plate 2 is inserted in slot 412 and the top one is inserted in a slot similar to slot 33 formed with the cooperation of the next succeeding support 26, as already described. The next succeeding louver plate is assembled in a similar fashion and the assembly of the plates is continued until the louver bed H is formed. The top edge of the top louver plate 26 extends into a slot 63 (Fig. 7) which is formed by sandwiching a relatively narrow strip between an overlying relatively wider strip 46 and the last support 28:. A nail Al or other fastening device may be used to maintain the strips in proper relationship.

When soap particles are introduced onto perforated bed ll and air passes through perforations 22 into this mass, the mass becomes aerated or fluidized and flows readily down the bed to the bottom thereof. At the bottom this fluidized mass is detained by a weir d9, of any desired height, which extends across the bottom of the bed and into opposing slots 50 formed on each of the inner sides of side walls l3 and M. The fluidized mass detained by the weir accumulates until it spills over the top of the weir. While the fluidized mass moves down the perforated bed and while it accumulates until it spills over the weir, cooling of the soap particles is effected without the formation of undue amounts of fines. As the mass spills over the weir most of the air separates from the soap particles and passes out through outlet 23. The cooled soap particles fall into discharge hopper 36, from which they may pass into a soap classifying device to separate the particles into sizes, or directly to the packaging apparatus, as desired.

The slope of perforated bed ll may be altered as desired to meet any need. A simple means of accomplishing this is to provide trunnions 5i and 52 on the opposite sides l3 and it of the cooling chamber adjacent the bottom of perforated bed H, and mount them for rotation in bearings in suitable side brackets 53 outside of the cooling chamber. A jack 54 or other similar lifting device, such as a hydraulic ram, for example, may be provided at the bottom of the cooling chamber adjacent end wall IE to pivot the entire cooling chamber at the trunnions and thereby alter the slope of bed ll. As is readily apparent, bed ll may bepivotally mounted within the chamber so that the slope of the bed may be varied independently of the chamber.

Some of the soap particles passing down perforated bed ll may fall through air slots 22 into air distributing chamber 59 and accumulate on 'the floor thereof. Chamber bottom i2 is provided ready access to all parts of the chamber for any desired purpose.

In Figs. 8 and 9 there is shown a conventional screw conveyor 5'? which runs lengthwise of air distributing chamber 59 at the bottom thereof and serves to carry the soap particles which fall through air slots 22 into chamber it to the exterior thereof. A deflecting plate 58 may be provided in the air distributing chamber l9 to deflect all soap particles which fall into the cham ber towards screw conveyor 5?.

In the operation of the system to cool spraydried soap particles, the particles are introduced onto the sloping perforated bed in the cooling chamber through inlet 58. These spray-dried particles may be entered into the cooling chamber directly from the bottom of the spray tower or from some intermediate stage of treatment of these particles to partially cool the same from the 170 to 195 F. temperature at which they are withdrawn from the spray tower. The air supplied to the cooling chamber through line H may be ambient air or it may be air which has been conditioned as to temperature and moisture content to effect the desired cooling in the product being entered into the cooling chamber. The entry of this produce into the chamber is preferably continuous as is also, of course, the entry of air through line 20.

It is manifest from the foregoing that the depth of the fluidized material on the sloping perforated bed will be progressively greater, from the inlet end to the discharge end. In order to provide sufiicient air to all portions of the fluidized mass on the bed to insure that it will be maintained in that state, horizontal partitions 60, extending between the side walls l3 and i lbelow the perforated bed, are provided to divide chamber I9 into air distributing ducts 6! which establish communication between inlet 2| and the perforated bed. The ends of-these partitions ad- These dampers serve to regulate the amount of air entering ducts 62. A similar damper is pivotaliy mounted on the floor of the chamber to control the flow of air through, the duct formed by the lowermost partition and the floor of the chamber. Dampers 62 are independently regulated from the exterior of the chamber, as by the handles 64 on the extremities of rods 63 which project through wall l3.

A similar flow control mechanism may be installed -in the cooling chamber illustrated in Figs. 8 and 9; however, in this embodiment of my invention'I prefer to use independently regulated dampers 65 positioned on rods 66 immediately beneath the perforated bed. These dampers are also regulated from the exterior of the chamber by the handles 61 which are secured to the pro jecting extremities of the rods. If desired, a plurality of these dampers may be ganged together for regulation by groups.

As pointed out above, the amount of aeriform body which may be used to convey and cool the particles on the sloping perforated bed maybe varied rather widely, as desired. For effective aeration of spray-dried soap particles of a particle size varying from about 50 to mesh and finer to substantially fiuidize the same and convey the same down the bed and over weir 49 to the aeriform body as to temperature and moisture content will, of course, be governed by the condition of the spray-dried soap particles to be treated.

When I refer to air in the foregoing, I refer not only to air but to other aeriform bodies such as gas, etc.

Iclaim:

1. An apparatus for cooling hot, spray-dried soap particles preparatory to packaging and which are at a temperature of about to ,ment to said perforated bed at contiguous sections throughout the length of said sloping bed, said means comprising horizontally disposed air ducts establishing communication. between said air inlet and said perforated bed, and dampers controlling the flow of air through said ducts.

2. An apparatus for cooling hot, spray-dried soap particles preparatory to packaging the same, comprising an enclosed chamber having an inlet for said hot, spray-dried soap particles and an outlet for cooled soap particles ready for packaging, a perforated bed sloping downwardly in a direction from said inlet to said outlet and di- F. and have a moisture content of about 8 to about 14%, comprising an enclosed chamber having a product inlet for said hot, spray-dried soap particles and a product outlet for cooled soap particles ready for packaging, a perforated bed sloping downwardly in a direction from said product inlet to said product outlet and dividing said chamber into an upper plenum compartment and a lower cooling air distributing com- 3 sloping bed, said means comprising horizontally disposed air ducts establishing communication between said air inlet and said perforated bed, and means for controlling the flow of air through said ducts.

ROBERT GEORGE WHITMAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,019,959 Hannam Mar. 12, 1912 1,213,962 Siler Jan. 30, 1917 1,472,314 Webster Oct. 30, 1923 1,567,031 Buensod Dec. 29, 1925 1,581,664 Schwantes Apr. 20, 1926 1,601,966 Harris Oct. 5, 1926 1,802,960 Simonds Apr. 28, 1931 1,942,418 Forte Jan. 9, 1934 1,971,566 Hutton Aug. 28, 1934 r 2,094,786 Flint Oct. 5, 1937 2,220,193 Ahlmann Nov. 5, 1940 2,316,664 Brassert et al Apr. 13, 1943 2,335,732 Bowen Nov. 30, 1943 2,346,500 Moore Apr. 11, 1944 2,371,619 Hartley Mar. 20, 1945 2,387,458 Mojonnier Oct. 23, 1945 2,404,944 Brassert July 30, 1946 OTHER REFERENCES Drying and Processing of Materials by Means of Conditioned Air, copyright 1929 by Carrier Engineering Corp.; page 59 discusses regain" or an equilibrium moisture content and page 181 gives a regain table for various substances including soap. 2

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