US1536873A - Preheating device for concentrating evaporators - Google Patents

Description

M s, 1925. 1,536,873 I L. J. BARTHELEMY PREHEATING DEVICE FOR CONCENTRATING EVAPORATORS Filed June 29, 1921 4 Sheets-Sheet l wrussss May 5, 1925. I

' L. J. BARTHELEMY PREHEATING DEVICE FOR CONCENTRATING EVAPORATORS I FiledJune 29, 1921 Y 4 sheets-sheet 5 L. J. BARTHELEMY PREHEATING DEVICE FOR CONCENTRATING EVAPORATORS Filed June 29, 1921 4 Sheets-Sheet 4 m 3 jk J v09' 00 k1 QO 0 QQO OOO/ 000 000 004 0 ooo 000 first body from whence it is conducted to the vapor-belt of the second body 6 and supplies heat for further evaporation of the juice contained within such body. In like manner the vapor from each body is suc cessively utilized in every succeeding body up to the last which is connected to the condenser. A large percentage of the water in the juice is thus evaporated in the quadruple efiect, leaving the sirup, as it is then called, in a much concentrated condition. After passing out of the last pan the sirup is clarified and subsequently passed to the vacuum pan, not shown, where the final evaporation takes place. However, the vapors after leaving the last or fourth pan 8, and also the vacuum pan, previously mentioned, pass on to the condenser at a very high temperature and ordinarily constitute a great loss and waste in heat. Moreover, a very large volume of water is required to condense such vapors which are very valuable as a fuel.

By means of the present invention, however, it is possible to utilize the heat of these vapors to the maximum extent and to reduce the temperature of the vapors going to the condenser so as to require less water to be used in the condenser. In other words, the invention enables the raw juice to be heated before it is subjected to the evaporating process usually carried on within the evaporating pan. It embodies a heater which may be made into a single integral structure, or made into sections bolted or otherwise fastened together, and may also be built in one or as many more stages as may be desired when a large capacity is required.

In itssimplest form or single stage, the heater comprises a cylindrical tube or drum 13 having annular flanges l4 and 15 provided each with an endless series of bolt or rivet holes 16. Integrally associated with the drum and formed upon the inner wall thereof so as to be centrally located between the open ends, is a plurality of closed compartments 17, arranged in pairs connected by a communicating passage 18. A similar arrangement of compartments 19 is had on the portion of the wall immediately opposite. The compartments of each series are closed by an upper wall 20 and a lower wall 21 while the front or inner wall 22 serves as a tube sheet and is accordingly pierced with a suitable number of openings, either five, eight or more, according to the number required. The tubes, indicated at 23, are supported crosswise of the drum, as shown in Figure 3, and in groups between the two series of compartments; the ends of the tubes being inserted through and expanded behind the tube sheet of opposed, corresponding compartments. Each group and the tubes. thereof, are all relatively spaced to provide for passage between them. and through the drum when the heater is in place on the evaporator. On opposite sides the drum is provided with short pipes, each of which constitutes an inlet or outlet for one of the series of compartments as found most convenient, since the juice can be entered. on either side. The juice enters the drum on one side through the inlet pipe, indicated in the drawings at 24, and circulates back and forth through the tubes of each group, passing from one compartment to the other until discharged through outlet 25 on the other side. Each compartment can be provided with a suitable hand hole and cover to permit the cleaning'of the tube or to permit the detaching and replacing of leaky tubes.

In its more elaborate form the heater may include as many stages or groups of compartments and tubes, as may be desired. for increasing the capacity of the device. In Figure 4:, a heater of the double stage is illustrated. This, as shown, is quite similar in construction to the single stage heater previously described, and shown to advantage in Figure 2 of the drawings. In fact, the double heater differs from the other only in that it consists of a unit having two separate and distinct sets of compartments and tubes arranged one above the other, as shown in Figure i, and providing, respectively, an upper stage 27 and a lower stage 28. Connecting the two stages and providing a passage from one to the other is a conduit 29 having a flow-control valve 30 and a drain valve 31 provided therein for the purposes indicated. The juice enters the heater through the inlet 32 of the lower stage and after circulating back and forth through the latter is conducted to the upper stage from which it is subsequently discharged through outlet 33. The openings indicated are for the rivets or bolt fasteners35 whereby the heater is secured to the flanges of the dome and vapor belt of the evaporator body to which it is applied.

To facilitate setting up the device and enabling it, also, to be shipped or otherwise transported without dif'iiculty, the unit or heater of both single and double type may be built in sections, such as indicated at 36, 37 and 38, in Figure 3; the end sections 36 and 38 being bolted to the middle section as shown at 39.

In applying the invention to the apparatus, a heater or unit of either the single or double type is placed between the vapor belt 10 and the dome 11 of an evaporating pan or effect, being fastened to the flanges of each, as illustrated in Figure 2. Whether the heater be of a single or double stage, its general association and method of use with an evaporator pan is the same, and hence, the following remarks concerning the use and operation of the double stage heater may be taken to apply equally well to the single stage- 'typeif As sho'wii in Fignre -IQ general arrangement? of" the luv heater or unit is placed in only the with and first body of"the quadruple effect but through pipe 42 through the lower. stage 28' of the heaterin the last or fourth body 8 of the apparatus, passingback and fourth through the tube until forced throughcom duit 29 and into upper stage, 27 from whence the third, et cetera.

it passes through pipe 40. into the heater of the first body or pan 5, entering the lower stage of the heater. After passing through the nest of tubes of'the upper and lower stages, the juice is discharged from the heat er and conveyed through discharge pipe 43 to a defecator forsettling, prior to its introduction into and subsequent subjection to the evaporating process within the'bodies or pans 1n the usual manner. During the usual operation of the apparatus the hot vapors arising fromv the steam heated juice within the vapor belt of the successive pans passes upwardly between and around the tubes of the heaters or units comprising the invention, and serve to heat the juice flowing therethrough. The vapors of the first pan pass into the second pan and from there into In this manner it is possible to utilize all the vaporsfifrom the severalbodies; utilizing the vapors of the fourth or last body, which are deemed coldest, and. the ones most usually wasted, for heating the cold juice; that is, as first introduced into the heater." By thus using these wasted vapors to first heat the raw juice: there is a gain of the heat or temperature that is sent to be cooled by the condenser. The coldest vapors are utilized to heat the juices at its coldest degree, as the heated juices come in contact with the hottest vapors. In this manner the high heat going from-one body to another is maintained, whichwould not be the case if the cold juices were fed against the hottest vapors. Besides, the raw juices coming in contact with thevapors that rise with the last body has tendency to carry off a certain amount in entrainment. Now, these globules when coming in contact with the cold juices that are in the tubes of the heater will serve two purposes; the globules will bethrown back into the vapor belt and then the vapors will heatthe juices to as high a temperature as possible. This is an important feature as it will prevent entrainment, etc,, heat the juices, and requires less water for the condenser.

. By the addition of more heating units or of units with more stages, the area of heating surface may be increased and the capacity in the are , possible ieaeaaee aie emanate-puss sa nae tlie wvorkof sugar ceirtrals can bbdbii witli bagasse alone,- as other heaters; new in use *in all factories usifrg "the eiihau'st steam will not immune used after" the efi ct's' arm started in} operation Mo1*'e" Bea custom be a dded; if desaeu, botlf the fourtl1, -thi rd and second bodies, so thatall the juices may be heated before entering the effect, and the temperature of the juice raised to the boiling point before it enters the first body for evaporation. This will enable the bodies or pans to do more work, and thereby increase the capacity of the plant. It is to be noted that the juices are passed through the lower stage first and then sent through the upper stage. This is done to keep the tube always well filled. Two, three or more of the units of thesingle stage type may be used together, if desired, to provide a heater of increased capacity, and when mounted, one above the other and fastened in place "between the vapor-belt and dome of an effect,will have the desired amount of heating surface to suit the capacity-of the plant. Both single and double types of heaters can be used 1nterchangeably. With a unit of two stagesv the heating surface is doubled and at less cost than if two single stage units are used for the same amount of heating surface, hence, its use is preferred in plants of large capacity although more expensive. In placing the units between the vapor-belt and the dome, the joints are made with putty as this gives no trouble, and the number of tubes in each group or stage will be governed by the capacity required to handle the juices from the'total amount of ground cane,.as all theraw juices must pass through the tubes...

a From the foregoing it will be seen that the invention provides a heater and pre-heater for the raw juices, which is economical in construction and so designed as to make use of the vapors from the various pans and effects of evaporating apparatuses of various types, it being here mentioned that the invention is equally applicable to all standard eflects, whether they be of the horizontal orvertical type. I desire it to be understood that I may make such changes in the construction, combination and arrangement of parts, materials, dimensions. et cetera, as may prove expedient and fall with the scope of the appended claim.

Having thus described my invention, what I- claim as new and desire to secure by Let ters Patent is:

v The combination with a liquor evaporator comprising a steam belt, a vapor belt and a dome, of a preheating device for the liquor disposed between the vapor belt and dome comprising a cylindrical drum, a set of compartments disposed on one side of the evaporator, a similar set of compartments disposed on the opposite side of the evaporator, the compartments of each set being arranged in stepped relation relative to each other, tubes connecting oppositely disposed compartments, the alternate compartments on the same side communicating, whereby a zig-zag passage is formed, and an inlet and an outlet for the liquor communicating with the end compartments of one set.

In testimony whereof I afiix my signature in presence of two witnesses.

LOUIS JOSEPH BARTHELEMY. Witnesses:

J UAN VALLDYAR, J ANVIL STEVNSON.

Images