US2358874A - Heat exchange - Google Patents

Description

Sept. 26, 1944. G. B. MULLOY HEAT EXCHANGE Filed NOV. 20, 1942 3 sheets -sheet 1 HIGH MTERL/A/E 40W WA TEE LINE P 26, 1944- G.- B. MULLOY.

HEAT EXCHANGE Filed Nov. 20, 1942 3 Sheets-Sheet 2 l mill/MM) Sept. 26, 1944. G. B. MULLOY 2,358,874

HEAT EXCHANGE .Filed Nov. 20, 1942 3 Sheets-Sheet 3 a ii 5% $1 eare. a

Patented Sept. 26, 1944 HEAT EXCHANGE George B. Mulloy, Wilmette, Ill., assignor to Mead, Mulloy Corporation, Chicago, 111., a corporation of Illinois Application November 20, 1942, Serial No. 466,353

'5 Claims.

My present invention relates to heat exchange and mor particularly to a means for heating a liquid by contact with a gas, such as water with steam.

Among the objects of the invention i to provide a novel means for producing heat exchange by supplying heat to a liquid, such as water in a sheet or film form, by the passing of a heated gas, such as steam, through the liquid sheet or film. Heat exchangers have been of various forms,

such as the open type, the closed type, the economizer typ and the spray type. The present invention comprises a novel film type of heater.

The open type heater-s may be grouped into three main classes; (a) those generally known as the live steam purifier type wherein live steam at'a relatively high temperature, such as about 300 F., is used to precipitate out scale, as sulphate of lime, magnesia, etc.; (b) those using exhaust steam at atmospheric or sub-atmospheric pressure, and (0) those using steam, to heat the water, at a low pressure ranging from atmospheric to 7 about twenty pounds pressure or so.

In any of the above types the steam usually enters the chamber into what may be called a mixing chamber where the water to be heated the water flows about or around the tubes to absorb' the heat transmitted from the steam through the walls of the tubes, and in the latter the water to be heated passes through the tubes while the steam surround these tubes to transmit heat through the walls of the tubes to the water therein.

The economizer type of heater may be similar to th closed type referred to above, wherein the hot or waste gases, such as the products of combustion, pass through the tubes surrounded by water, or pass about the tubes through which the water flows.

In the spray type of heater the heating medium,

such as steam, is supplied in any suitable way into a chamber where the water, under suitable pressure, is sprayed or atomized to commingle with the steam and settle as hot water to the lower part of the chamber. In this case also some of th steam condenses and gives up latent heat of vaporization to the water mist or the like, the collected hot water being the product of the condensed steam and the heated water spray.

The present invention, more particularly, comprehendsa novelmeans for formingand moving the water to be heated in a thin-sheet or film, as

' over a porous urface, and the passing of steam through such sheet or film, as causing the flow of steam through the porous surface, to give up heat contained in the steam and to also condense the steam so that the heated water and the condensate collect as hot water in the lower part of the chamber where the water and steam contacting is efiected.

More particularly the novel device comprises an outer or main chamber into which the heated water is collected and an inner or auxiliary chamber into which the steam is supplied, the inner chamber having a wall with a plurality of openings, such as slits among a series of spaced rods, and means in the outer chamber and so located near the walls of the inner chamber as to produce a fiow of a sheet or fihn of water over said Another feature of th invention is to provide I the above referred to device with a water seal for condensed steam or water overflow to prevent loss of steam or vapor from the collecting chamber.

Another object of the invention is to provide a novel means for producing heat exchange by flowing a thin sheet or film of water over the surface of a wall having openings through which steam may pass to pierce said film and to cause the steam to so act upon the film as to heat up.

Other' objects, capabilities, advantages, features, process steps and the like are comprehended by the invention as will later appear and as are inherently possessed by the invention,

Referring to the drawings:

Fig, l is a vertical sectional view with a part shown in elevation through a heat exchanger constructed in accordance with the invention;

Fig. 2 is a transverse sectional view taken in a plane represented by line'22 in Fig 1 of the drawings;

Fig. 3 is a fragmentary sectional view on an enlarged scale taken in a plane represented by line 3--3 of Fig. 4 of the drawings;

an alternate form of means for holding the rods.

in place.

Referring now more in detail to the drawings, the embodiments selected to illustrate the invention are shown as comprising a container or outer chamber I having a bottom 2 to which is connected an outlet pipe 3 for feeding hot water from the compartment 4 in the lower portion of the chamber I. To the bottom 2 may be also connected a blowout connection 5 having any suitable valve 6. The chamber or container I has a top I having a steam inlet fitting 8.

Within the chamber I is an inner chamber comprising a hollow cylindrical portion 9 having at itsupper end a flange ill suitably secured to the top I. To the lower end of the cylindrical member 9 isconnected, .in a manner more fully explained hereinafter, a lower portion I of this chamber. This portion I 0 has a bottom wall II. The wall of the portion In is of cylindrical form and is provided with a plurality of openings through which steam entering by way of the inlet 8 and into the chamber compartment 9 may pass through into the outer chamberI, mor fully explained hereinafter.

Spacedly below the top I is an annular wall or partition I2 suitably secured at itsouter rim-by way of suitable means such as angle bar ring I3 which may be welded or otherwise fastened to the wall of the outer chamber I, as shown.

The inner rim of this wall I 2 has a depending lip I4 concentric with the cylindrical wall of the chamber portion 9 and spaced therefrom to provide an opening I5 for the downward flow of a cylindrical sheet of water over the outer surface of the lower portion I0 of the inner chamber. On the wall I2 is provided an upstanding annular wall I6 which with the side wall of the chamber I and the wall I2 provides an annular chamber or channel I! for containing the water to be heated. To the top 'I is connected a vapor vent pipe I8 the lower end of which extends through, in any suitable manner, the wall I2 as shown in Fig. l. Atone side the outer chamber I is provided with an inlet means I9 through which water, such as that coming from the condensers of engines, coils, pumps, or other similar devices, may flow into the annular channel I'I. Inthe event additional water is to be supplied to the channel I! to maintain the level of the water therein a supply pipe 2-3 may be connected'to supply water into the channel I1 and controlled by a suitable valve, such as a gate valve 2 I, connected by way of operating means 22 in turn connected to a float 23 within the chamber I and.

operative by the water level in the lower portion of the container I as shown in Fig. 1.

Should the steam condense at a rate asto accumulate at a higher level than the high water level indicated in Fig. 1 a relief duct 24 may be provided for the escape of the condensed steam. It is preferable to connect this relief duct with a .water seal or trap. See Fig, 6. The trap in this case is in the form of a U-shaped duct 25 with inlet and outlet connections at the top of this trap, the inlet being connected to the outlet 24. As the steam condenses in the chamber I it flows into the trap 25 and the condensate is maintained at the level of the duct 24. The liquid in the trap 25 will prevent the escape of the steam vapor into the atmosphere or otherwise.

In the illustrative embodiments the lower portion II] of the inner chamber 9 comprises an annular series of vertical rods 26 spaced from each other at given distances to provide Vertical openings or slits 2'I. Said series of rods constitute a cylindrical surface or wall of the lower section ID of the inner chamber. The lower ends 28 of these rods rest upon the bottom II and in an annular channelformed between a pair of concentric rings 29 and 30 secured to the bottom II as by spot welding or otherwise. The upper ends 3I of the rods 26 are disposed in contact with the lower end portion 32 of the chamber portion 9, as clearly shown in Fig. 3. In order that these rods may be maintained in proper spaced relation it is preferable that the alternate rods 'be provided with upper and lower collars 33 and 34 the thickness of the collar gauging the spacing of. the rods. Of these rods, a certain number of them, six of them given by way of example in this case, and designated 35 in Fig. 4, are in fixed position by welding the lower ends of these 'rods 35 to the bottom 'I I and by welding the upper end portions of these rods 35 to the lower portion 32 of the chamber portion 9. These rods, therefore, constitute posts or suspending members for the bottom I I.

The other rods 26 are merely placed in position with their lower ends 28 in the channel between the rings 29 and 30 and with their upper ends 3I in contact with the lower end portion 32 of the inner chamber 9. When assembling these rods it is always necessary that those carrying the collars 33 and'34 are alternate with those not carryto laterally extending fins 40 fixed at their inner ends to the hanger posts 35. After the rods are in place .these segments 31 may be placed against the rods and bolted inplace so as to hold the removable rods in position.

. Referring to-Fig. 7, ,in lieu of the bar 36 an annular ring 4| of angle or Z cross sectional form may be suitably secured to the wall of the chamber portion 9 over the upperends of the rods and at a suitable spaced relation thereto with the lower flange of the ring 4I extending down sufiiciently to overhang the upper ends of the rods 26 as shown. In this case when the rods are inserted the upper ends are moved upwardly into the channel between thefiange of the ring 4| and wall so as to form a continuous ring sheet flowing down over-the inner annular portion 42 of the wall I2 and time lip I4 where thecylin- ;drical sheet of water will flow downalong the rods 23gandover the openings 21 between such rods. See Fig. 5. The water will form a film on the outer and inner surfaces of these rods as shown in Fig. and by reason of surface tension will also fill the slits 21 between the rods 26. This sheet or film of water flows downwardly over these rods which constitute in the aggregate a surface with openings therein, spanned by the.

film of water. The steam being admitted through the inlet 8 and into the chamber portion 9 will pass through the slits 21 and pierce this film of water so as to give up its heat to the water. The steam will also condense and mix with the water. Both combined will flow down into the lower chamber portion 4 of the chamber l to be accumulated there or stored.

The water being used may form scale depending more or less upon the character of the water. This scale may collect on the rods 26. To remove the scale the rods may be removed and suitably treated and then replaced or other clean rods put in their place. Or as an alternative, it may be merely necessary to strike the rods with a hammer or the like to shake ofi the scale. Any scale that falls within the chamber upon the bottom ll may be easily removed by removing some of the rods to make an opening.

It is intended as part of this invention that the rods be made of a material to which scales will not attach themselves or easily form. The rods may be made of any suitable metal, such as iron or steel, and may be coated with a metal or an enamel to which scale will not readily adhere or cohere.

While I have herein described and upon the drawings shown a few illusrative embodiments of the invention, it is to be understood that the invention is not limited thereto but comprehends other constructions, details, arrangements of parts, features or the like without departing from the spirit of the invention.

Having thus disclosed the invention, I claim:

1. A heat exchanger of the liquid and gas contact type, comprising a main chamber having a compartment for the collecting of liquid therein, an auxiliary chamber in said main chamber and having an upright wall provided with vertically extending elongated openings, said openings extending from end to end of said wall and means in the main chamber for conducting a sheet of water to and over said wall for forming a continuous film of water flowing down over the surface of said upright wall and the openings therein, and means for supplying steam into said auxiliary chamber for passing through said-openings and said film.

to provide upright openings between the bars,

2-. A heat exchange device for heating a liquid said bars being individually insertable in place with the lower ends of the bars resting on said bottom and the upper ends of said bars contacting the lower end portion of said skirt, and means surrounding the bars to normally maintain them in place.

3. A heat exchange device for heating a. liquid having an outer and an inner chamber respectively having outlet and inlet means, said inner chamber comprising an upper skirt and a bottom spacedly below the skirt with means connected to the skirt for supporting said bottom, a porous wall extending from the lower end of said skirt to said bottom and composed of a series of upright elongated bars spaced from each other to provide upright openings between the bars, said bars being individually insertable in place with the lower ends of the bars resting on said bottom and the upper ends of said bars contacting the lower end portion of said skirt, and means surrounding the bars to normally maintain them in place, said bars having the alternate bars thereof carrying spacing elements for spacing said bars to provide said openings.

4. A heat exchange device for heating a liquid having an outer and an inner chamber respectively having outlet and inlet means, said inner chamber comprising an upper skirt and a bottom spacedly below the skirt with means connected to the skirt for supporting said bottom, a porous wall extending from the lower end of said skirt to said bottom and composed of a series of upright elongated bars spaced from each other to provide upright openings between the bars, said bars being individually insertable in place with the lower ends of the bars resting on said bottom and the upper ends of said bars contacting the lower end portion of said skirt, and means surrounding the bars to normally maintain them in place, said surrounding means being connected to said skirt and having a portion thereof extending around the upper portions of said bars' for holding the bars in place.

5. A heat exchange device for heating a liquid having. an outer and an inner chamber respectively having outlet and inlet means, said inner chamber comprising an upper skirt and a bottom spacedly below the skirt With means connected to the skirt for supporting said bottom, a porous Wall extending from the lower end of said skirt to said bottom and composed of a series of upright elongated bars spaced from each other to provide upright openings between the bars, said bars being individually insertable in place with the lower ends of the bars resting on said bottom and the upper ends of said bars contacting the lower end portion of said skirt, and means surrounding the bars to normally maintain them in place, said surrounding means having means for connecting the same to said bottom supporting means, and being composed of segments removably connected to said connecting means.

GEORGE B. MULLOY.

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