US2284165A - Heating system - Google Patents

Description

' May 26, 1942.

s. R. PORWANCHER HEATING {SYSTEM Filed June 23, 1939 2 Sheets-Sheet l ?Z/e/e for javzzlef$ olYuarzrlzeiz Patented May 26, 1942 HEATING sxs'rlnvr Samuel R. Porwancher, Chicago, IlL, assignor to Drying Systems, 1110., Chicago,

tion'of Illinois 111., a corpora- Application June 23, 1939, Serial No. 280,737 1 Claim. (01. 34-86) This invention relates .to heating systems and. more particularly to reclaiming heat usually exhausted to the atmosphere or'otherwise dissipated without recovery in drying systems of paper making machines that employ air as the heat circulating medium.

In paper making machines, heated air is cir'- culated over the moist fibrous web to effect the desired drying or removal of moisture therefrom, andthis air is thereafter exhausted to the atmosphere or otherwise dissipated without having the heat thereinextracted therefrom. The primary object of the present invention is to recover heat from the heated drying air passing from a paper making machine prior to the exhausting of such air, to the atmosphere or other dissipation thereof. 7

Another object is to utilize heat recovered from the heated drying air from a paper making machine in any of a wide variety of ways.

A more specific object is to employ heat recovered from'the drying air passing from a paper making machine to heat or assist in heating the building in which the machine is housed or in the processing of the pulp fromwhichthe paper is produced.

Other objects and advantages of thepresent invention will be apparent from the following description wherein reference is made to the accompanying drawings in which Fig. 1 is a transverse sectional view taken through a building in which a paper'making machine is housed, and withwhich one form of my invention is associated; and

Fig. 2 is a horizontal sectional view of the building and apparatus shown in Fig. 1.

In the accompanying drawings I have shown' a paper making machine I 0, the details of which are unimportant for present purposes, and as is illustrated in Fig. 1 the machine is preferably mounted on a floor ll of a building [2 above the lowest floor of such building.

through the upper portion of the hood. As herein'shown two exhaust or vent ducts l4 and M are provided at spaced points :along the top of the hood l3. (Fig. 2'). In the present instance each duct I4 and 14' opens into an enlarged housing portion I5 and a'vent, stack l6 extends through the roof of the building l2 from each portion. [5. 'As shown in Fig. 1, each stack I 6 has draft inducing means, such as an exhaust ,fan ll, mounted therein and'such means is, in

the present "instance, driven by a belt l8 from a motor l9 mounted outside of the stack. The fans operateto withdraw heated air from the zone of the machinethrough the hood l3, ducts. l4 and I4 and housing portions l5 and cause discharge of the air so withdrawn to the atmosphere through the stacks I6.

The air which is so circulated is heated by conventional air heating means (not shown) and when drawn through the exhaust ducts l4 and hi this air still retains a large proportion of the heat which has thus been supplied, plus considerable moisture absorbed from the paper in the paper making machine. In accordance with the present invention, the heat in this exhaust air is recovered in such a way as to be 'usable, either in the paper making processor for heating the building I! or for other purposes. To this end, each of the housing portions l5 has a heat exchanger mounted therein. Thus, as

' shown in Fig. '2, the portion It: in the passage 14 'In the operation of a machine of this type the ture-laden air withdrawn from the zone of the machine I0 is collected. The air flows from the hood t3 through a plurality of ducts opening has a coil 20 so mounted therein that the air drawn through this housing must pass over the coillfl on its way to the exhaust stack l6 leadingfrom this housing. A similar coil 20is correspondingly mounted in the housing portion l5 in the duct l4. Preferably the coils 20 and 20' have radiating fins or plates'zl thereon so as to increase the efliciency thereof as heat transfer devices. p g V Aheat circulating mediumysuch as water, is passed through the coils 20 and 20 so that as the heated air from the zone of the ,machine flows over the coils or heat exchangers 20 and 20' 'heat therefrom may be transferred to the medium circulated through the coils or heat exchangers. Heat so taken up by the medium circulated through the heat exchanges 20 and 20 is carried by the medium to other heat exchangers or the like where such heat may be utilized.

As heatis extracted from the moisture-laden air by the coils 20 and 20, the temperature of the air usually drops slightly below its dew point,

whereby a film of moisture is deposited upon the coils. This is an advantageous feature in that hence a more eflicient heat exchange arrangement is afforded. V

To this end the two heat exchangers or absorbing devices and 20' are incorporated in a fluid circulating system whichincludes a liquid supply tank 22 on the lower floor-23 of the builda ing 42, and by means of a motor driven pump 24,

liquid, which may be water,-from the tank is forced upwardly through a riser pipe 25 (Fig. 1 m V 29 and 29 to have heat picked up thereby transferred to other than intake air for the building 1) and thence through a branch pipe line 26' (Fig. 2) into one end of the'heat absorbing can:

20 and through another branch pipe line2'l to;

'one end of the corresponding coil 20'. A pipe line 28 leads from the other end of the coil 2!! to a heat exchanger or transfer device 29 which,

in the present instance, is positioned in an air intake duct 30 through which fresh air is supplied to the interior of the building [2. As here in shown the intake duct 30 is connected toreceive airthrough a grilled opening 3| in a side wall 32 of the building I2, and is provided with an intakeblower 33 which is belt driven from a motor 34. Air drawn from the exterior ofthe building l2 throu'ghthe duct 30 is=discharged by-the blower 33 into a riserduct 35 from which it is' distributed about lthe building l2 through side discharge openings in connected overhead distributing-ducts36. 1 I i The heat exchanger 29 is herein shown as being of the-same type as the exchangersn and 20and since 'w'ater heated in the heat exchanger '20 .flows throughpipe line 28 to theheat exchanger the duct 30 having a blower 33 discharging through a riser 35' and overhead distributing ducts 36 disposed along side 32' of the building. 3

The intake duct 3ll' is also provided with a 'heat exchange device 29, similar to the heat exchanger 29, and which is supplied with heated water from the heat exchanger 20' through a pipe line 28. fThis liquid is discharged intothe tank 22 by a return pipe line 31 which, as shown in Fig. 1, joins with the line 3 1 at 40. i By way of example, if air withdrawn from'the zone of the machine It to flow through" the ex; haust ductsld and HI and housing portions-l5 over the heat exchangers 20 and 20"has a tem perature of from 170F. to 180 F.', sufficient heat may be taken therefrom in the heat exchangers 2n and 20' to reduce the temperature of this'air to about 90 F.. before discharge of the air through the stacks IS. The heat so extracted from the air in the heat exchangers 20 and 20 is carried by the medium circulated through these heat exchangers to the heat exchangers 29 and 29 where it may be utilized to heat fresh air taken in through the intake ducts 30 and 30' to a temperature of from F. to F. and this air I so heated is discharged from the ducts 36 and 36' to heat theinteriorof the building I2.

, .Of course, the'pheat circulating medium flowing through the heat exchangers 20 and 20' could'be directed to means other than heat exchangers as l2. ,For example,.water heated in the heat ex changers! and 20' could be employed in the paper making process or be otherwise utilized.

While Ihave illustrated and described a selected embodiment of my invention, it is to be understood that this is capable of variation and modification and I therefore do not wish to be limitedto the precise'details set forth but desire to avail myself of such changes and alterations as fall the purview of the following claims m-' 3 7 a The combination with'a'building having side 'di uin' isicirculatedfor the purpose of absorbing moisture-from paper material produced therein,

I a heat: reclaiming system c'omprising an exhaust hood overlying and f partiallyjenclosing saidj machine,- an exhaust'passage leading from said hood and communicating with the atmosphere outside the building, an exhaust fanin said passage for withdrawing heated air from the vicinity of the machine and discharging the same to atmosphere, a heat exchanger in said exhaust passage having coils through which a liquid may be circulated out of direct contact with the air flowing throughsaid passage but in heat exchange relation'itherewith to absorb heat therefrom, there being an inlet passage in' one of the building side walls, a heat transfer device situated adjacent said inlet passage 'and remote 'from said heat ex-, changer and having coils through which a 'liq uid may be circulated out of direct contact withair passed over said heat transfer device but in heat exchange relation; therewith to transfer heat thereto, means interconnecting the'coilsof said heat exchanger and said heat transfer device in a closed circulatory system, and pump' mea bodied in said system operable to circulate a liquid therethro'ugh for'carrying "heat absorbed in said heat exchanger to said heattransfer device, and a distributor duct communicating with the inlet passage and having a discharge outlet for air positioned adjacent the upper regions of the building and'remote from the paper making machinei i 7 I SAMUELRPORWANCHER.

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