US1021486A

US1021486A - Evaporating apparatus having multiple evaporation.

Info

Publication number: US1021486A
Application number: US62109811A
Authority: US
Inventors: Waclaw Rusiecki
Original assignee: Individual
Current assignee: Individual
Priority date: 1911-04-14
Filing date: 1911-04-14
Publication date: 1912-03-26
Anticipated expiration: 1929-03-26

Description

W RUSIEGKI. I EVAPORATINGAPPARATUS HAVING MULTIPLE EVAPORATION.

APPLIOATION FILED APR.14, 1911.

Patented Mar. 26, 1912.

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COLUMBIA PLANDGRAPH co.. WASHINGTON. D c.

W. RUSIEGKL EVAPOBATING APPARATUS HAVING MULTIPLE EVAPORATION.

. APPLICATION FILED APR. 14, 1911. 1,021,486. Patented Mar. 26, 1912.

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W. RUSIEGKI. EVAPORATING APPARATUS HAVING. MULTIPLE EVAPORATION.

AP'PLIOA-TIQNIFILED APR.14, 1911.

3 SHEETS-"SHEET 3.

WITNESSES. [NVEN'T'O'HI 6 Arron/van.

COLUMBIA PLANOGRAPH (IO-,WASHINGTON. D. C.

Patented Max 26, 1912. V

UNITED STATES PATENT OFFICE.

WAGLAW RUSIECKI, 0E RAKITNAJA, RUSSIA.

EVAPORATING APPARATUS HAVING- MULTIPLE EVAPORATION.

' the other chambers obtain their heat for evaporation from the steam or vapors formed in the first chamber. In order to obtain favorable and rapid evaporation, suction of the steam or partial evacuation in the chambers is employed in the known manner.

A primary object of my invention is to increase the output and efficiency of the evaporation process, which end I attain by arranging and constructing the heating batteries in an improved manner.

One illustrative embodiment of my invention is represented by way of example in the accompanying drawings, wherein Figure 1 is a plan of an evaporating apparatus comprising four elements, Fig. 2 a vertical longitudinal section on the line AB in Fig. 1, Fig. 3 a section on the step-shaped line G-D-EFG KL in Fig. 2, Fig. 4 a side elevation and Fig. 5 a front elevation according to Fig. 4 as seen from the left.

Similar letters of reference indicate corresponding parts throughout the several figures of the drawings.

Referring to the drawing, each element of my improved evaporating apparatus is an ordinary horizontal evaporator of box shape, in which the tubes b k iv, h forming the heating surface are not arranged longitudinally, but transversely. The first, or lowermost element, into which the liquid to be boiled enters through the valved pipe al has on its side a steam admission chamber M to which the steam for heating is supplied through one or more supply pipes a, in order to be sucked away by a pump or the like as condensed. water by way of the branchpipe 6 after passing through the Specification of Letters Patent.

air and the like.

Patented Mar. 26, 1912.

Application filed April 14, 1911. Serial No. 621,098.

heating tubes and out of the chamber N The branch pipe 0 is for removing gases,

the elements are connected one with another in such a manner that the steam chamber of the preceding element plays the part of a steam admission chamber for each of the following elements. In this manner the steam chamber of the first element serves as steam admission chamber for the second, and so on. The second, third, fourth and any other elements are provided with the chambers N N N having outlet-pipes b 6 I2 and c c 0 for conducting away the water and gases which are removed in the known manner by means of automatic devices or pumps.

The level of the liquid, 6. g. the level of the cane-juice in sugar-mills, must be lower in the lowermost element than the lowermost tier-of heating tubes in the next following element, and so on so that the foam of the juice and the particles of spray from one element cannot the following.

The valved branches d d (5 merely serve for conducting the juice from one element to the next following elements, in connection with the branch-pipes c c 6 The juice is sucked successively through the pipes and valved branchesv e (1 e d and 6 d from one element into another. The inspissated juice is removed through the branch-pipe c of the uppermost chamber None of the other ele-' 'ments has a steam admission chamber, but

pass into the tubes of by means of a pump. In order to be able to regulate both the supply of the juice and its passage from one element into the others special valves are provided. The branch 0 is for conducting the vapor of the juice in the uppermost element to the condenser.

P P andP designate inclined baffleplates for preventing the juice from passing from one element into the small tubes in the next. As will be understood from Fig. 2, the bafiie-plates areattached to one longitudinal wall and to the two end'walls. The free spaces or gaps It R R between the top edges of the battle-plates and the other longitudinal wall of the elements serve for conducting the vapors formed in these elements into the small tubes of the following elements.

Q Q Q Q, designate manholes while S designate peepholes.

The small tubes forming the heating surfaces may either be beaded into the walls of the chambers or packed therein with the aid of india-rubber rings.

In order clearly to explain the mode of operation of an evaporating plant arranged in the aforesaid manner, I will assume that the steam of the first element is not to be employed for any other purpose except for evaporation work in the other elements. Further, I will assume that chemically pure water is evaporated which forms no sediment on the small tubes, that, for the heating, steam from the engines is used at a pressure of about three atmospheres, and that the vapors pass out of the uppermost element into the condenser and into an airpump which maintains in said uppermost element a constant, rarefied atmosphere of 60 ems. column of water. Under these conditions the absolute pressure of the exhaust steam equals 1.5 atmospheres and the absolute pressure in the air space of the fourth element will be 0.2 atmosphere.

When all the elements have an equal area, the pressure in the first element will amount to 1.17 5 atmos, that in the second element will amount to 0.850 atmos, that in the third element will amount to 0.525 atmos, and in the fourth element will amount to 0.200 atmos.i. 6., the difference of pressure in two adjacent elements is 0.325 atmos.:3.8 m. of a column of water. Assuming that the specific weight of the liquid in the third element is 1.3., the column of this liquid which is to balance a column of water 1.3 m. high mustbe 3.313 254 111. It follows that with a difierence of 2 m. in the levels of the liquid in the third and fourth receptacles, the liquid can be unimpededly sucked from one element into another. When the difference in pressure between each preceding and following element is equal, the difference in temperature will also be equal and will be approximately 1 1 C. Now when the difference in temperature between the elements is equal and the heating surface the same and made of the same material, and when the heating tubes are of the same diameter, it is generally assumed that the capability of performance of the heating elements is the same always supposing that chemically pure water is evaporated in all the chambers The constructions of all customary evaporators known heretofore is based on this principle. In practice it has been found, however, that the first elements have a much greater capability of performance than the last. Experiments and consideration have shown that the cause of the reduction of the capability of performance of the following elements is that the volume of steam increases with the diminution of the pressure.

According to Zeuners table 1 kg. of steam has at a pressure of 1.5 atmos. a volume of 1.1268 cub. m. and, consequently, when the pressure in the 1st element is 1.17 5 atm. a volume of 1&197 cub. in. when the pressure in the 2nd element is 0.350 atm. a volume of 1.9295 cub. m. and when the pressure in the 3rd element is 0.525 atm. a volume of 3.0465.

As all evaporating apparatuses have heretofore been so constructed that in all the elements the total of the sections of the tubes through which the steam passes is almost equal, it follows that with an assumed ve locity in the first element of 20 meters per see, the velocity in the second element must be 25 m., in the third 35 m., and in the fourth 60 m. In other words, in spite of the diminution of pressure the velocity must rise, but this, however, is contrary to law. In fact, in apparatuses known heretofore no increases in velocity took place, for which reason the steam in the last element could not flow over the entire surface, whereby, again, a considerable portion of the heating surface remained unutilized and the evaporation did not correspond to the heating area. Theoretical considerations show that, when the velocity of the steam in the tubes of the first element is 20 1n. per second, for the purpose of most advantageously giving up its heat, this velocity at the low pressure must be less than 20 m. in the following elements and in no case greater. This conclusion is based on the following considerations: Supposing that a long pipe is immersed into water of constant temperature and steam of any desired pressure is admitted into one end of the pipe, as the distance from the inlet increases the temperature of the steam will gradually fall until it is equal to the temperature of the water. Calculations show that with a steam pressure of 1.5 atmos, a copper tube 20 mm. in diameter, and a temperature of the water of 20 C., the temperature of the steam at a distance of 25 m. from the inlet is equal to the temperature of the water of 20 C. Consequently at this point the delivery of heat equals zero, whereas the delivery of heat at the inlet is (11220) 22, when 112 is the temperature of the steam, 20 the temperature of the water and 22 the coefficient of the delivery of heat. The diminution of the capability of delivering heat takes place uniformly and amounts per meter run to (112-20) 22: 25:91 calories. In this manner the 1st meter run transmits 2025 calories, the 10th:2025(81.10):1215, the 20th:2025(81.20):405 and the 25th: 2025(81.25):0. From this it follows that the average amount of heat delivered by a tube 25 m. long is 1012 calories,

C by one 20 meters long.

and lastly by one 10 meters long:

2 1620 calories.

the elements, and for this purpose the total section of all the heating tubes of the individual elements must be in such a relation one to another as the volumes of their vapors, in other words these sections must be inversely proportional to the steam pressures in the individual elements. heating surfaces in all the elements are equal and if the same consist of small tubes of equal diameter, it is clear that for observing this rule the number of tubes in each following element must be greater than in the preceding one, whereas their length must be less. But as the capacity of the tubes increases relatively to their shortness, it follows that in an evaporating plant based on the aforesaid principle all the elements will have an equal capacity, and the capacity of the entire plant must be greater as compared with that of plants known heretofore. The plant in the illustrative embodiment constructed according to my new principle has heating surfaces of the following dimensions: 1st element: length of tube 3 m., number 112 pieces; 2nd element: length of tube 2.5 m., number 140 pieces; 3rd element: length of tube 1.75 m., number 196 pieces; 4th element: length of tube 1.25 m., number 301 pieces. As men tioned above, these dimensions only relate to an evaporating plant in which the steam in the first chamber only is employed in the plant and in which chemically purewater is used. If, instead of water, cane-juice or another liquid is to be boiled, the area of each following element must of course be rather largerthan that of the preceding. This enlargement must correspond to the coefli- If the.

cients of the diminution of the power of conducting heat, which are determinable in practice in each case, in consequence of the inspissation of the juice and the sediment in the tubes. If steam for heating other apparatus is withdrawn from one of the ele ments, e. g.,.tl1e third, the area of this ele ment, and also the areas of all the preceding elements mustbe increased by a corresponding number of tubes.

I claim r 1. In an evaporating apparatus of the character described, the combination, with a series of box-like horizontal elements arranged adjacent to each other and stepshaped one above theother, of a system of rectilinear heating tubes arranged transversely of the same and communicating with the preceding chamber, liquid supply pipes connecting each preceding element with the next following element, a liquid supply-pipe for the lowermost element, means for supplying steam to the transverse heating tubes of the lowermost element, and means for conducting the steam away-from the heating tubes of all the elements.

2. In an evaporating apparatus of the character described, the combination with a series of box-like, horizontal elements arranged adjacent to but step-shaped one above the other, of transverse heating tubes arranged in each element and communicating with the next preceding element, liquid supply pipes connecting each preceding element with the next following element, a liquid supply-pipe for the lowermost element, means for supplying steam to the transverse heating tubes of, the lowermost element, and

means for conducting the steam away from the heating tubes of all the elements, the total cross-section area of the tubes in each element being greater in each following element than in the preceding element.

3. In an evaporating apparatus of the character described, the combination with a series of box-like, horizontal elements, ar ranged adjacent to but step-shaped one above the other, of a plurality of rectilinear heating tubes arranged transversely in said elements and communicating at one end with the next preceding element, liquid supply pipes connecting each preceding chamber with the next following chamber, a liquid supply-pipe for the lowermost element, means for supplying steam to the transverse heating tubes of the lowermost element, and means for conducting the steam away from the heating tubes of all the elements, the length of the tubes in each element being less in each following element than in the preceding one.-

'4. In an evaporating apparatus of the character described, the combination, with a series of box-like, horizontal elements arranged adjacent to and step-shaped one above the other, of a plurality of rectilinear heating tubes arranged transversely in said elements and opening at one end into the preceding chamber, valved liquid supply-pipes connecting each preceding chamber with the next following chamber, a liquid supply pipe for the lowermost element, means for supplying steam to the heating tubes of the lowermost element, and means for conduct ing the steam away from the heating tubes of all the elements, the level of the liquid in each following element being higher than that in each preceding element but below the lowermost tier of heating tubes in the next element.

5. In an evaporating apparatus of the character described, the combination, with a series of box-like, horizontal elements arranged adjacent to and stepshaped one above the other, of a plurality of rectilinear heating tubes arranged transversely in said elements and opening at one end into the preone element to the heating tubes of the next following one.

In testimony, that I claim the foregoing as my invention, I have signed my name in presence of two subscribing witnesses.

. WACLAXV RUSIEGKI.

WVitnesses:

GYPRIAN KossoBUDsKI, AUG. MIGHIs.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. 0.