US1143743A - Evaporating appratus. - Google Patents

Description

L. P. BAUER.

EVAPORATING APPARATUS.

APPLICATION FILED APR. 29. I9II.

PalentedJune 22, 1915.

2 SHEETS-SHEET 1.

L. P. BAUER.

EVAPORATING APPARATUS.

LJi AJWABQ APPLICATION FILED APR.29,I9I1.

Patented June 22,1915.

2 SHEETSSHEET 2.

LOUIS 3P. BAUER, 0F JPN,- ILLINOIS.

EVAJPOTING APPARATUS.

masses.

Specification of Letters Patent.

Patented. June 22, NW5.

Application filedApztlctB; 2 .911. Serial'llto. 624 M.

To all whom it may concern:

Be it known that 1, Louis =P. Bapnma citizen of the United States,.res1d1ng.at

Pekin, in the county of Tazewe'll and State.-.

evaporators and particularly to vacuum e vaporators- It pertains primarily to a structure in an apparatus for evaporatingliquids of various kinds by which a very high efiiciency may be maintained at all times.

Many evaporating pans are so equipped that the heat necessary. for evaporation cannot be applied to a suflicientdegree to obtain the quickest and best results... Furthermore, a high efliciency of these pans cannot be maintained since the interior structures are such that they soon become clogged and covered with incrustations, the heating surfaces after a short time-being rendered less and less useful by such incrustations, and in order to restore efficiency the surfaces must, of course, be cleaned requiring the apparatus to be ,shut down. When cleaned the apparatus may stand at say 100% efliciency in heat transmission, but later this gradually falls to a very low point, because the steam introduced thereto cannot yield the best results by reason of the adhering matter.

Havingthis in mind one ofmy objects is to produce an interior structurefor a vacuum pan in which the entire heating surface can always be utilized to the best advantage. That is to say, anobject is to provide such an arrangement in anevaporatingapparatus that its parts can be maintained practically free of: adhering matter so that its efliciency will be maintained at practically 100%, or an efliciency after long use which will substantially equalthat at which it stood at the beginning:

Another object is to provide a structure in a vacuum. pan-in which-the heating elementor eiementsiare'made to evaporate the liquids under treatment either by immersion of said element in the liquid orby treatmg said. liquor through the well known film process of evaporation these methods being elective, the latter, however, being preferred;

Another object is to provide a vacuum panuin which the largest heating surface that .it is possible to produce in a pan, can always be maintained.-

Another and important object is the provision of an evaporating apparatus yielding rapid results-in the evaporating process. A further object-is the accessibility to all the parts of an evaporating apparatus by providing for the withdrawal of its heating and evaporating element from the pan for making repairs.

A further .objectis to provide a vacuum pan-with-an open side through which the mechanism that assists in the 'process of evaporation can be'introduced or removed, such open side being provided, of course, with a tight closure.

A further object is to provide an evaporating mechanism for a vacuum pan composed of-a' number of parts built up to constitute a complete heating unit, all said parts being. clamped together for immersion in the'liq'uid to be'evaporated.

A further object is to provide, in a vacuum pan, a mechanism for the reception of the heating member and to provide means for automatically keeping the said-member cleared of deposits by revolving one of the parts relatively to the other.

Other objects and advantages will appear in the following specification aided by the accompanying drawings in which,

Figure 1 is a rearelevation of a vacuum pan. Fig. 2 is a vertical longitudinal section of the casing of the vacuum pan. Fig. 3 is a sectional elevation of the lower half of the same-0n a much enlarged scale. Fig. 4 is a rear elevation of the lower half of the'pan, also on an enlarged scale. Fig. 5 is an elevation of a heating element, and Fig.6 is a longitudinal section of certain parts shown in Fig. 3 on a greatly enlarged scale.

From wide experience with various types of' evaporators it has been found that although any one of them may operate satisfactorily and with a high efliciency under certain definite conditions, it may fail entirely to give satisfaction under other conditions. For example, it may be well suited to the demands of sugar plants but when called upon to evaporate distillery slop, tankage, or steepwater in starch and glucose plants, or, in general, liquid which tends to form voluminous and slimy precipitates during concentration, the evaporator may be a complete failure. From this knowledge I have been able to construct a vacuum pan having a heating element that can be kept clean during operation so as to maintain the desired high efliciency and to so arrange the structure of the entire apparatus that this element may be readily and quickly removed from the pan in case of needed repairs.

Those familiar with evaporator-s realize the serious delays caused by'leaks in the ,heating system, the adhering of scale and incrustations, the necessity of boring out plugged vents and the numerous other sources of trouble all of which the structure to be described herein is designed to eliminate.

I prefer in my vacuum apparatus when using the socalled pan indicated as a whole by the letter A, to make it in two sec tions for convenience, there being an upper and a lower one indicated by a and b respectively and joined in any usual manner as, for instance, by means of flanges indicated' at 0; At the top of the upper section is a flanged outlet ,connection 03 for a vapor pipe not shown, while the lower section at the bottom is provided with a similar flanged connection 6. What I term the rear side of the pan, for convenience, is provided with an opening B having a plate 0 as a closure therefor. This said plate is provided with a central opening D to'receive certain rotating portions, to be hereinafter described, while the front side of the pan has a' similar but larger opening E. The

heating member or unit for evaporating purposes is made up of a series of hollow disks F indicated clearly in Figs. 3 and 6. The latter figure shows these disks on quite a large scale as compared with Fig. 3, most of the said disks being shown in transverse section. They are each composed of two dishedplates f provided each with a circumferential flange g placed upon one another, as indicated, forming a receptacle for steam. The disks thus made up are clamped together near their centers with rings or gaskets G between them, there also being within each disk between the plates f a gasketor ring I-I. When all the disks and said rings are secured together as, for instance, by means of bolts J, a conduit K is created through the entire series of disks or throughout the entire length of the unit. It is understood, of course, that the center portions of all the disks are removed leaving openings of substantially the same diameter as the bores of the said rings all of the latter serving to make close joints so that there can be, no leakage of fluids, using red-lead or similar material if desired to make anabsolutely tight joint. \Vhen thus assembled a bore L is also created which extends through all of the rings and the disks F as shown by previously having provided holes in all of these parts to be brought into register. Communicating with said bore L within each disk is a pipe M secured in each of the rings H by means, for instance, of screw threads M, the opposite open end of each said pipe terminating adjacent to the inner wall of the disk at the flanged portion of the same. In each said ring H, also, are two openings M permitting communication between the bore K and the interior of each disk. Against each end of the unit made up of the series of disks is a plate. One is indicated at N, and the other at N the said bore L being closed by the said plate N, and these plates serve as the actual clamping members through said bolts J. The plate N is provided with a bore 0 which communicates with and is perpendicular to the said bore L, while a centrally disposed bore P in said plate communicates with said bore 0 and lies parallel to the said bore L, said plate having a central extension Q, wherein said bore P is centrally disposed with reference to the circumference of the disks and this extension Q lies within the bore D of the plate 0, there being any usual stufling-box R to prevent leakage around said extension. Communicating with the bore P is a pipe S, there being a packing gland at T also to prevent leakage around said pipe.

The opposite plate N is provided with a bore U communicating with the interior bore K of the disks and rings and upon this is placed the flange V of a hollow stem or pipe V which flange may be secured to said plate N by means of a series of bolts but two of them being shown, however, at V in Fig. 3. The stud-bolts thus provided serve to clamp the said stem or pipe and the plate N rigidly together, any means (not shown) being used to provide for a fluid tight joint between them. The said stem or pipe V extends through the bore E of the front of the pan and a suitable stuflingbox W provides for maintaining a'tight joint. Secured to said stem or pipe in suitable manner is a worm wheel 2 which meshes with a worm 3 mounted on a shaft l supaaaaraa said pipe or stem V it being understood,

however, that any other means of rotation may be used. A flange 6 on the outer end of the pipe provides for the attachment of any suitable steam connection (not shown) all of which, however, will be understood later.

ln the device illustrated I prefer to rotate the series of disks which are partially immersed in the liquor intended to be evaporated and, as stated, this is done through the worm and worm-'wheel'and although the extension Q and sterner pipe VT may constitute shafts to support the disks in the bores D and B other ways'of supporting the disks may be used. I prefer-to mount the unit between spiders 7 for convenience in removing the mechanism from the pan in the easiest possible way. Each spider is provided with a body of sutlicient area,

Fig. 4, to be bored out at 8 to receive the plates N, N and each has, also, a series of arms, two opposite ones 9 of which are connected by bars 10 to move on runways 11 shown in said Fig. 4 and indicated by dotted lines in Fig. 8. Preferably it provide a series of balls 11 for the runway to support these bars and for providing for easy movement of said bars in removing the mechanism for the pan. The spiders further include two arms 12 disposed at right angles to the said arms 9. As a matter of fact their exact position relative to the arms 9 is not important, that described being merely a preference. Connecting the opposite arms 12 of each of the spiders'is a bar 13, Figs. 3

and 4, which serve to space said spiders apart and secure them rigidlytogether.

The'numeral 14 indicates a series of chains :whose ends are secured to the members 13 in suitable manner, each chain having a position between two adjacent 'disks F as clearly shownin Figs. 3 and 6 although in these figures they have not been shown in full in order to leave the drawing clear and easily read. In Fig. 4:, also, the position of one of the chains is shown wherein at its middle it lies against .one of the rings H, its extremities lying upon the full exposed surface of each disk outward from said rings.

It is now to be noted that since the disks are adapted toorevolve independently of the spider and thechains 14: the -are continually rubbed o'r sdrap'ed by sai' chains resulting in keeping those surfaces entirely free of adherin matter and incrustations which naturally orm, each chain being of such a size as to lie snugly between two adjacent disks so as to insure actual frictional, wiping or rubbing contact with both. It is to be stated, however, that other means for producing the rubbing of the disk surfaces metal surfaces cleaned. It may be stated further, however, that the most important ofice' of these chains, ropes, or equivalent members, is'that of keepingthe liquors in a turbulent condition and in a marked degree preventing incrustations forming upon the heated disks.

It is evidentthat as the disks revolve the tendency of the liquor is to follow in the direction of rotation and to be drawn up between the disks during such rotation. But the chains or other members used lie in the path of the liquor, resulting in keeping it in agitation upon the disk-surfaces keeping them free and clean of adhering matter.

The disks in their rotation will naturally cause the liquor to take up more or less of a whirling motion in the same direction but thechains break up andprevent said whirling motion.

I provide means for introducting steam as the evaporating agent and provision is also made for the removal of air, gases, and

the water of condensation. In the present instance the steam is introduced through any pipe connection, not shown, which may be bolted to the flange 6 on the outer end of the rotating stem or pipe V; thence passing into the central conduit IQ where' it enters the disks F through the openings M in the rings H while thepipe S at the opposite end of the apparatus is the discharge for air and gases and condensed steam. The disks in rotating and in being partially immersed in the liquorunder treatment are continually covered with a film of'said liquor whichthe steam within quickly evaporates; the vapor passing off through the upper part of the pan and the connection (Z at the top. Water of condensation formed in the disks will be withdrawn through the pipes M as their open ends become immersed therein, due to pressure of steam within the disks, the water being forced up from time to time through said pipes into the bore L, and finally out through the bore P, as the pressure of steam i here given. The width of the pan measured.

between the closure C and the front end of said pan is in the neighborhood of 30 inches while the thickness of the disks is about three quarters of an inch; there being a space between each. disk of from one half 15.

inch to five eighths of an inch, and the diameters of said disks are in the neighborhood or 36 inches. It is thus seen that a very large heating surface is providedand in fact a much larger one than would be 'posslble by. any other form of heating device such assteam coils, for example. Since the spiders remain stationary and have the rating apparatus of which I am aware.

Instead of rotating the series of disks the spiders may be rotated, the said disks in "this case effecting the evaporation by their immersion only. However, to assist in evaporation the chains in rotating with the spider will act to keep the exposed surfaces of the disks covered with a film of liquor which will aid-materially in the speed of evaporation. I

If atany time it is desired to withdraw the mechanism from the pan for repairs it is only necessary 'to remove the stud-bolts V These are readily reached from the front side of the pan by removing a covering plate V of a hand hole V in said front side, the series of disks being turned little by littleso as to bring the several said bolts uppermost, one at a time, where each can be reached with a wrench through the said hole. Having removed these, the closure C at the rear side of the pan having been removed, the entire inner mechanism can be readily withdrawn, the flange V being removed from the plate N. After repairs the mechanism is replaced in the position it first occupied.

Other types of evaporators have used rotating heating elements but none of them have been arranged upon a supporting track so as to be easily and quickly withdrawn but must be withdrawn at the expense of considerable hard work and loss of time since theends only thereof are supported' -within the receptacle in which the element lies. In my preferred form of element, however, made up of disks which 1t is the desire to partially submerge, and which 11; 1s also the desire to rotate, the structure is such.

that said element almost entirely fills the pan or receptacle and a track is desirable in order to easily and quickly remove from and return the element to the pan. Necessarily, also, a support movable upon the track and in which the element can rotate is used as a novel construction as differing from evaporators having an element slidably mounted on a track but not adapted to rotate and which therefore requires no support between it and the track.

The ease and readiness with which the disks F can be built up to make a heating unit by the using of the several dished plates f together with the described rings or gaskets G H is important since but little fitting of parts is required thus resulting in a saving of time. And furthermore the unit can be made of any desired extent of heating surface, more or less of the disks being used to suit requirements.

In my apparatus a much larger heating surface is provided than is possible with any other plan of the closed type working under vacuum and having the same interior space, the efficiency of the same is maintained at the highest point, and both the film method.

of evaporation and the common method of immersion are possible.

I desire to state that it is not my intention to be confined to the exact structure shown in the drawings and described herein since various changes may be made that will lie within the meaning and intent of the inven tion. Any suitable means may be used to support the disks when they remain stationary and any suitable driving connection may be employed to impart movement to said chains. When the disks are to remain stationary the pipe M may be duplicated within each disk so that while one is uppermost, as shown in Fig. 5 for the remoy'al of the air, the other may open into the bottom of the disk for removing the water.

The invention also contemplates the rotation of the disks and chains relatively in opposite directions this being possible by certain adaptations of the structures. And beside this the device is susceptible of other changes.

'lhe area of heating surface of the unit made up of the disks is very large compared with the space occupied, and, in fact, it is of any system of pipe coils occupying the same space, and the disks being made preferably of copper have a high heat conductivity. Much stress has been laid, 'in practice, upon the advantage of film evaporation and several types of apparatus are based on this method but most of them have not been productive of the best results. In the present instance the advantage of film evaporation is gained and the surfaces of the disks are always kept clean.

The liquor circulates in the narrow spaces between adjacent disks and this coupled with the high conductivity of the heating surfaces makes this circulation practically as productive of good results as types of evaporators of much larger size intended for film evaporation even though the said disks larger than it would be possible by the use may remain stationary, which may be one form of my device as stated previously. Furthermore, my form of. evaporator is far more satisfactory from the standpoint of adaptability to the evaporation of all classes of liquors which is not true of many other types. The speed of rotation and level of liquor are under control and can be so reglated as to produce conditions of the very highest efficiency. r

The structure I employ has not. been used in an evaporating apparatus adapted to work under vacuum which is the system by which most all liquors can be handled to the best advantage when considering the matter of time, low cost of the heating agent (spent steam) and ease and rapidity of handling large quantities of liquor.

Having described my claim 1. In an evaporator, the combination of a invention, I

receptacle and a track therein, of a support mounted upon and adapted to move along the track and including two spaced end portions, :1 member having hollow trunnions at its ends andcarried byand rotatable in said end portions, a separate conduit communicating with each said trunnion, and a series of-fiexible members carried by the support and lying in close proximity to the said rotatable member.

2. In an evaporating apparatus, a receptacle for the liquor to be evaporated, a rotatable member therein comprising a series of hollow disks separated from one another by a narrow'space, a conduit extending through the disks conducting a heated gas thereto,

and a flexible member lying in each space between adjacent disks, the disks rotating relative to said members, their surfaces rubbing upon the members in their rotation.

3. In an evaporating apparatus including a receptacle for liquor to be evaporated, a

track, a rotatable heat containing member in said, receptacle, a member to carry said rotatable member and mounted upon the track and adapted for withdrawal from the receptacle, means adapted for frictional engagement with the rotatable member, and means for rotating said member.

4:. In an'evaporator the combination of a receptacle for the liquor to be evaporated, a rotatable member therein comprising a series vof hollow disks each provided with a pair of openings in its walls, supporting trunnions for said member, rings interposed between the walls of all of the disksand con- 'stituting, together with one series of said a vacuum pan, of a series of hollow spaced members rotatably mounted in said pan, means to space apart said members, a'steam conduit directly communicating with the members, a discharge conduit for water, a pipe in each member communicating with said discharge conduit, and a flexible member suspended between the adjacent surfaces of adjoining members.

6. In an evaporating apparatus the combination of a pan, a series of hollow disks, spacing members interposed between the several said disks, a spacing member inclosed in each said disk, means to clamp the series of disks and members together, hollow trunnions for carrying the series of disks, there bein two separate bores extending through alIthe disks and said members, and a pipe in each disk communicating with one of said bores. V

'Z. The combination in an evaporating apparatus, of a series of plates adapted in pairs to constitute receptacles for steam, there being two spaced openings in each plate, a ring lying at each side of each plate and provided each with apertures corresponding with those of the plates and together with the latterforming two separate conduits throughout the series, there being an aperture in each of the rings lying within the receptacles and each of said apertures communicating with one of the conduits, and a'pipe in each receptacle connected with the other of the conduits.

8. In an evaporating apparatus including a receptacle for the liquor to be evaporated, a member within said receptacle made up of a series of hollow disk-like portions, a ring interposed between each pair of portionsfa ring also interposed between the walls of and within each said disk-like portion, said mit communication of the latter with said conduit, there being a conduit extending through the rings and the walls of all the disk-like members, and a pipe within each disk communicating at one end with the last named conduit. its other end having communication with. the interior of said disk.

9. An evaporator comprising in its construction a series of hollow disk-like members and a series of rings interposed betweenthem and a series of rings within them, said members having openings in their walls to correspond to the openings of the rings, there being an opening also 1n each said ring and in each wall of each of the members separate from the openings first described, the two separate openings 1n the members and the rings when all are clamped In testimony whereof I afiix my signature, 1n presence of two wltnesses.

LOUIS P. BAUER.

Witnesses:

CHARLES V. MILES, EUNICE BECKUM.

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