US1586817A - Regenerative air preheater - Google Patents

Description

June 1,1926.

F. LJUNGS'TRM REGENERATIVE AIR PREHEATER Fiied August 5, 1922 s sheets4sheet 1 June 1 1926. 1,586,817

F. LJUNGSTRM REGENERATVE AIR PREHEATER F11 t 5. i922 3 eats-sheet 2 FIG. 2. ,6

June 1Q, 1926. 1,586,817

F. LJUNGSTRM REGENERATVE AIR PREHEATER Filed August 5,1922 3 sheets-sheet 5 .Patented dirne ll, i926. narran atraen entrant carton.

FRIEDRICH LJUNGSTRM, F LIDINGO-BREVIK, SWEDEN, ASSIGNOR T0 AKTIEBULGET 'QJ'UNGSTROMS ANGTURBIN, STOCKHOLM, SWEDEN, A CORPOTEON,

REGENERATIVE AER FREHEATER.

lApplication i'led August 3, 1922, Serial No. 579,543, and in Sweden September l, 1921.

rlhis invention relates to regenerative air preheaters. ln regenerative air preheaters in, which a rotor containing a heat absorbing and heat rejecting materialheremafter called, for ease of description, regenerative mass, rotates continuously or 1ntermittently within two channels through which gases pass, one of which is warmer than the other, whereby heat is transferred from the warmer gas to the cooler one, the

drawback is met with that there is a transfer of the gas accompanying the regenerative mass from one channel to the other. ln my application Serial No. L1:60,(500 for Letters Patent a regenerative air preheater is disclosed in which a tight joint at the partitions between the channels is obtained by the use of sector plates of such a size that they entirely cover one of the sections into which the regenerative mass is divided.

As disclosed in that application such a section passes from one channel to the other the sector plates on either end of the regenerator rotor simultaneously cut oid this section containing regenerative mass. When so cut oiil this section contains gas enclosed between the sector plates such gas being oit the same nature as the gas present in the channel from which the said section is just G about to move. This transfer of gas is particularly inconvenient when the regenerator is used as an air preheater for boilers or the like, in that tlue'gases are thereby transferred to the fresh air.

rlhe present invention comprises means for preventing such a transfer of gas from one channel to the other and consists in arranging the walls of the rotor, the partitions between the channels for air and gas, and the sector plates in such position relative to each other that `lfresh air may pass during the rotation into the channel for lue gases through that section of the rotor which is just about to pass into the air channel. rlhis is preferably attained by displacing the sector plates with respect to one another, and a suilicient amount of scavenging air is obtained by maintaining constant the relation between the speed of the driving t5@ means which rotates the air preheater and that of the driving means for the fans which force the gases through the air preheater.

and by maintaining a higher pressureiin the air channel than in .the gas channel.

The invention is illustrated in the accomright hand side,

. edge of the rotor.

panying drawings in which Fig. l shows diagrammatically one embodiment which is represented in Figs. 2. 3, 4 and 5 as applied in actual practice. Fig. 2 being a longitudinal section taken on line 24-2, Fig. 3 with the rotor and other parts in elevation, Fig. 3 a plan view thereof, Fig. 4t, a cross-section of part of the rotor taken on line 4 4 of Fig. 5 and Fig. 5, a plan view of part of the rotor. Fig 6 shows diagrammatically another embodiment.

ln the embodiment illustrated in Figs. 1-5 inclusive, reference character 1 designates the rotor of t-he regenerator. rlhe rotor is divided into compartments such as 2, 3 and 9 by means of walls 13, which are preferably situated radially o the rotor. Regen- -erative mass 12 is placed in the Ysaid com-y partments. By way of example, l have shown, as one form of regenerative mass capable ofy use with my invention, alternately disposed substantially straight and corrugated plates, although it is to be 'understood that any type of regenerative material may be used. The regenerative material is described and claimed in my co-pending application Serial No. 460,600 above referred to. As shown in Fig. t, walls 13 extend the full height of the rotor but the plates of the regenerative mass l2 do not extend the full height but are so arranged that a space is lett at the top and bottom extending across the whole of each compartment, the purpose of which will b e apparent as the description proceeds. rlhe rotor rotates in the direction of arrow 8.

Partitions 4, 5, 6 and 7 serve to separate the channels 16 and 17 for air and flue gases respectively. ln the embodiment shown in the air passes upwardly on the left hand side and the :due gases downwardly on the as indicated by arrows. Attached to the partitions are sector plates 10 and 1l. rlhese sector plates are indicated by shaded surfaces in Fig. l. Fach sector plate is of such a size that it covers one compartment of the rotor and lits snugly to the ln previous constructions, these sector plates were placed directly opposite each other with respect to the rotor. By so doing, at certain times in the operation of the regenerator, a whole compartment would be completely blocked on giving 'the disadvantage, above pointed out, that a certain amount ot due gases would be carried over in such a blocked ottl compartment i'rom the tlue gas channel to the air channel.

In the embodiment 'of present invention shown in Figs. 1 5, these sector plates are displaced with respect to each other, on that end ot the regenerator rotor where the rotor travels out ot the flue gas channel 1T -and into the air channel 16, the upper sector 10, with the flow ot gases as shown, being in advance ot the lower sector plate ll, as regardsI the direction ot` rotation oi` the rotor. 'l`hat is. the lower open end of any and'each sector-shaped compartment is first closed by the lower sector plate ll and then after turther travel ot the compartment in the direction ol the arrow, the upper open end of the compartment is closed by the upper sector plate 1f). By this means, in operation` there will be a time when each compartment is 1n communication with the tlue gas channel on the one hand and the air channel on the other. For example, as shown in Fig. l, sector plate l has not vet closed ofl' the upper opening ot` compartment 9, whereas the lower opening ot' compartment t) has passed beyond that point at which it is entirely cutI off b v sector plate ll and is in communication with the air channel. Now at this time, by maintainingT a somewhat higher pressure in the air channel than in the lue. gas channel, a small amount ot` air can pass from the air channel, through coinpartment 9 and into the flue gas channel, carrying the flue gases in the compartment haelt into the flue gas channel. rlhis is in part eflected by the arrangement of the regenerative material in the rotor, which is shorter than the outer cylinder and the walls of the rotor so that there is a space across the whole top and the whole bottom ot the compartment, thus permitting air to pass across the whole bottom of the compartment. up through all the passages ot' the regenerative mass, across the top of the compartment and out into the tlue gas channel.

2i and designate fans which are driven together with the rotor l, preferably by a common driving means such as electric motor QG. The fans are directly connected to the motor shaft and the rotor is driven from the shaft by means ot` a belt or chain, or in any other way. It ther rotor and the t'ans are driven Yfrom separate motors, the speeds ot' the latter must be controllable in such a manner that. the proper relation between the speeds ot' the driving means is always maintained. rflic regenerative mass on passing from the tlue gases channel to the air channel has its highest temperature and evidently will be somewhat cooled by the scavenging air. However, as this air will subsequently pass through another section of the rotor .1 in the direction of the tlue gases, this heat willl lalso be utilized in the same manner as the heat from the liuc gases. In order that no more than the requisite quantity ol" air 'shall pass through the section to be scavenged, in that an unnecessary vigorous cooling of this section would otherwise take place, care should be taken that no more than a certain quantity ot air, depending on the speed ot the rotor, will be allowed tio pass through the same, and such delinite quantity of air is obtained by the driving means of the fans which force air or gases through the rotor and the driving meansI of the rotor having constant speeds relatively to each other, in such a manner that, for example, on the speed of the rotor being doubled, the speed of the fans will likewise be doubled. By the employment of the vtaus it is moreover possible to regulate the pressures so that gas will never pass into the air channel.

Fig. (i shows a modification in which the walls and 5 and 6 and 7 which separate the channels for air and flue gases are all situated in one plane. rlhe scavenging el'- fect obtained in Fig. l is here attained b v the walls between the rotor sections having such oblique positions as to allow air to pass in the direction ot' the broken line arrow through each rotor sect-ion to the flue gas channel while the rotor is rotating.

lith the arrangements described an increased etiiciency is obtained in the rcgenerator and in the boiler or the like with which it is connected, in that the air is not contaminated in the regenerator.

It should be evident that a combination of the structures ot Figs. l and is conceivable, the rotor being t-hen devised according to Fig. l but the partitions t to 7 straight as in Fig. (S. lthis is simply attained by the sector plates l() and ll being displaced relatively to one another the same as in Fig. l. Such an embodiment is obviously comprised in the principle ot' the invention above set forth it is only considered that the sector plates form part of the partitions. Various other modifications` are obvious within the scope of the invention.

*What I claim as new and desire to secure by Letters Patent of the United States is 1. A regenerative heater comprising a first channel for a fluid, a second channel for a fluid, a regenerative material, meam 'for etfecting e relative motion between said channels and said material and means to pass fluid from the first channel through the part, ot the material which is about to enter said channel and into the second channel.

2. A regenerative heater comprising a l'irst channel for a Huid, a second channel for a fluid, a regenerative rotor adapted to move within each of said channels and means to pass fluid from the first channel through the part of the rotor which is about to enter the rst channel and into the second channel.

3. A regenerative heater comprising a plurality of channels for fluids, a regenerative rotor adapted to move within'each of said channe-ls and means to pass iiuid from one channel to another through the rotor in the opposite direction to the rotation of* the rotor.

4. A regenerative heater comprising a plurality of lchannels for fluid, partitions separating said channels, a rotor adapted to move 1n each of said channels, walls in said rotor dividing the lrotor into'compartments, regenerative material in said compartments, said compartments being open at the ends`of the rotor, sector plates on the partitions at opposite ends lof the rotor adapted to cover said openings, said sector'iplates being so disposed with respect to said Walls that when a compartment passes from one channel to another there is simultaneously a communication between the compartment and each of such channels.

5. A regenerative heater comprising a plurality of channels for fluid, a rotor adapted to move Within each of -said chan` nels, walls dividing said rotor -into compartments,- regenerative material in said compartments, openings in said compartments, a sector plate adapted to close one of said openings in a given position of the rotor with the edge of the sector plate in line with one of said Walls, a second sector plate at the opposite end of said compartment so arranged in the said given position that its corresponding edge is out of alinement with said Wall.-

6. A regenerative heating device comprising a casing, partitions in said casing forming a plurality of channels for Huid, a rotor in said casing, walls in said rotor dividing the same into compartments, regenerative material in said compartments, means to move said rotor through said channels,and means whereby each compartment when it passes from one channel into another is simultaneously in communication with both channels.

In testimony whereof I affix :my signature.

FREDRIK LJUNGSTRM.

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