US1951971A - Heating apparatus - Google Patents

Description

March 20, 1934- J. R. FARBRIDGE HEATING APPARATUS Filed No'v. 5, 1931 4 Sheets-Sheet 1 4 Sheets-Sheet 2 J. R. FARBRIDGE HEATING APPARATUS Filed Nov. 5. 1931 March 20, 1934.

March 20, 1934 J. R. FARBRIDGE HEATING PPARATUS Filed Nov. 5, 1933 4 Sheets-Sheet 3 Match 20, 1934. J, R, FARBRlDGE 1,951,971

HEATING APPARATUS Filed Nov. 5, 1931 {Sheets-Sheet 4 Patented Mar. 20, 1934 HEATING APPARATUS John Robert Farbridge, Colombo, Ceylon Appiication November 5, 1931, Serial No. 573,288 In Great Britain November 7, 1930 5 Claims.

This invention relates to heating apparatus of the kind comprising a plurality of separated flues or passages through or on each side of which the heating medium passes, and on eachv side or 5 through which the medium to be heated passes.

The invention relates particularly to apparatus of this kind adapted to yield a supply of hot air for drying and other purposes and has more particular reference to the apparatus covered by l thepresent applicants co-pending application Serial No. 462,324 of which the present application is a continuation in part.

Y An object of the invention is to provide improvements in apparatus of the above kind l whereby it is possible to obtain a higher ratio of economy in regard to the quantity of fuel consumed by the apparatus relatively to the amount `of heat imparted to the air or other medium passing through the apparatus and to control and conserve the temperature and heat of such apparatus. v

` With this and other objects in View the invention Vconsists in the features to be hereinafter described, illustrated in theV drawings and dened in the appended claims.

In the accompanying drawings Figure 1 is a front Yelevation of a form of apparatus according to the invention which lis adapted to burn liquid fuel;

Figure 2 is a part sectional plan taken on the line I-I-H of Figure 1; Y

Figure 3 is a part sectional front elevation taken on the line J-J of Figure 2, and

Figure 4 is a sectional side elevation taken on the line K-ls` of Figure 2.

The general construction and arrangement of apparatus according to the particular embodiment herein described is similar to that disclosed in the said copending application Serial No.

462,324 and need not be fully described herein, it being sumcient for an understanding of the present invention to mention that it comprises air heating chambers forming a plurality of isolated flue passages formed from groups of tubular elements, hot furnace gases being caused to traverse such flue passages so that heat is imparted to air or other medium which passes through the tubular due-forming elements, the hot air or other heated medium being received in a suitable chamberwhile the furnace gases after traversing the nue passages are led away through a main smoke ue to a chimney or the like which may be located at the back of the apparatus or at the front as desired.

In carrying the invention into effect in one convenient manner and as applied to. apparatus of the kind described in the said co-pending application Serial No. 462,324 which comprises a central fireplace or combustion chamber ,1, ues 2 and multitubular air-heating or nue-forming 60 elements 3 carried by top and bottom tubeplates 4, 5, the flue-forming members 3 are inclined towards each other in an upward direction so that they enclose a combustion chamber of substantially triangular cross section. f 65 The arrangement of the tube plates 4, 5 for the flue-forming elements is substantially the same as that disclosed in the earlier specification but the tube plates are modied somewhat in order to suit the inclined arrangement of tubes or ilueforming elements, the upper tube plate 4 being of angular form and built up of a plurality of angular members which are supported at their ends upon a framework 6. 1

The combustion chamber 1 enclosed by the 75 tubes on either side is thus of substantially triangular form in cross section and the arrangement ofthe inclined tubes has the advantage that no brickwork or other furnace crown is required while it has the further advantage that the apparatus may be made perfectly smoke tight and a comparative saving in the cost of manufacture and construction thereof is made possible.

The said air-heating elements 3 are so spaced that the nues or chambers enclosed between them g5 decrease progressively in width from the front of the apparatus towards the back as is clearly shown in Figure 4. This arrangement is adopted because in apparatus of the above kind the velocity of thegases in each iiue passage diminishes gradually in a direction away from the smoke outlet 7 so that the velocity of? the gases through the flue passages at the back of the apparatus will be at a maximum and the Velocity of the gases through the flue passages at the front ,will be a minimum. This difference in the velocity of the furnace gases is thus compensated in the present invention so as to obtain a uniform heating of the flue-forming elementsv by successively increasing the spacing of the .fiues in a direction away from the chimney. Alternatively, the spacing of the fiues may be otherwise varied, so that this effect of uniform heating is obtained.

The tubes 3 are reduced somewhat in diameter for a short distance at their upper ends, as indicated at 34a, from the part where they leave the neck 3b of the top tube plate 36c and enter stuinng boxes 3a formed in the latter the tubes touching one another in the neck of the tube plate but being separated from each other, in the neighbourhood of their reduced portions, by annular spaces which permit of packing being applied all around these portions of the tubes.

Retarders or baiTles 3e are inserted in the tubes to prevent too rapid passage of the air to be heated, these retarders or baffles causing the air to circulate in contact with the internal surfaces of the heated tubes and thus increasing the rate at which the air absorbs heat from the tubes and adding to the efficiency of the apparatus.

The smoke ue passage 9 provided at the bottom of the apparatus is formed as a separate unit,

this having the advantage that the eiiiciencybf the apparatus as regards the elimination or" any smoke or other impurities from the furnace entering the heated air will not be impaired in any way due to there being any unevenness in the flooring construction where it is desired to install the apparatus.

This smoke flue unit comprises a plate 10 having sides l1 welded or otherwise secured thereto and -channel irons 12 or other suitable supports riveted kor otherwise secured to such sides and adapted to support in part the lower tube plates 5 yfor-the flue-forming elements 3, the supports for the latter at'the bottom being also constituted byangle irons 13 or other suitable means secured within the opposite side walls of the heating apparatus. Y

The sides'of the smoke flue unit are provided with valves 14 for controlling the flow of the furnace gases to the smoke outlet 7 while the top plate of the said unit is adapted to support rirebricks 15 or any other suitable structure enclosing and forming the lower part of the combustion chamber. The said valves 14 for controlling the-flow ofthe furnace gases from the flue passages 2 Yto'the smoke'outlet 7 via the main smoke iiue 9 maytake the form of iiap valves common to all the outlets from each battery of iiues or a separate flap valve may be provided for each flue passage outlet, thesaid valve or valves being'suitably supported in position and adapted to be operated from the outside by hand wheels 16 so as to regulate the volume of gases allowed to pass through the multitubular smoke flues 2.

Byso regulating the volume of gases passing `through the flue passages the temperature of the hot-fair passing throughv the interior of the flueform-ing elementscan be regulated as desired.

Iheapparatuss fitted with a liquid fuel burner 17-which is-adapted to -give a vertical ame and is disposed inthe lower half of the combustion chamber'and supplied with air and fuel through pipes 18, 19 respectively. A fan 20 is provided at ythesinoke outlet '7 whereby it is possible to have a complete mechanical control of the combustion in the furnace, the said fan operating to draw and/or force the required amount of air into the furnace to complete combustion while it may also be arranged to operate so as to withdraw the gases from the furnace.

By the Ause'of a fan or like device the heater is under-complete control and is not aiected by atmospheric changes which interfere with the draught of an ordinary smoke chimney.

A preheatingchamber 24a is provided at the front of `each air-heating chamber and the air supply to the burner 17 is conveyed by a pipe 24D through one chamber and the oil supply is likewise conveyed to the burner through the other chamber by a pipe 24C.

The air is caused to flow downwardly through the tubes 3 by providing a cold air chamber 38 having an inlet 39 under the control of a regulating valve 40 and a fan 41 adapted to draw the air downwardly through the tubes and through a hot air chamber 42. The openings 5c in the bottom tube plate are graduated in size, being larger the nearer they are to the furnace.

I claim:

1. Heating apparatus comprising in combination, walls dening a combustion chamber, walls defining a heat exchange chamber having communication with the combustion chamber so that the combustion gases may flow from the combustion chamber through the heat exchange chamber, means for withdrawing the combustion gases from the apparatus after said gases have traversed the heat exchange chamber, and banks of tubes disposed within the heat exchangechamber so as to form fiues, for the passage'of'thecombustion gases, of successively increased areasinl a direction away from the end of the combustion chamber where the combustion vgases are dis-` charged from the apparatus'the said tubes,which serve for the passage of the medium to be heated, having inlet openings which, in each bank of tubes, are successively decreased in size in a direction away from the combustion chamber.

2. Heating apparatus comprising in combination, walls defining a combustion chamber, walls defining a heat exchange chamber which receives the combustion gases from the combustion chamber, a fan disposed adjacent tonne endof the. combustion chamber and adapted to control the ow of the combustion gases andto exhaust same and a plurality of banks of tubes disposedwithin the heat exchange chamber with the "end tubes of each row in close proximity tothe adjacent walls ofthe said heat exchange chamber and'with the tubes in each bank in close contact with each other, the said banks of tubes being also disposed within the heat exchange chamber so as to form Aiues, for the passageoi the combustion gases,- of` successively increased areas in a direction away from the end of the Acombustion chamber where the said fan is located, and the said'tubes,l which serve for the passage of the medium to be heated, having inlet openings which, in each bank'of 125 tubes, are of successively increased areas in a direction away from the combustion' chamber;

3. Heating apparatus according to claim2 comprising a fan adapted to control the passage through the tubes of the ,medium tovbe, heated;

4. Heating apparatus according to claimi2'comprising a stuiing box for the ends of said tubes, which latter have their end portions of reduced diameter adapted to permit of the entire circumferential surfaces of the tubes being packed, the portions of the tubes of greater diameter; being adaptedfor close contact with one another.

5. Heating apparatus according to claim 2 having a heat exchange chamber on each side ofthe combustion chamberv and having the banks of JOHN ROBERT FARBRIDGE.

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