US1673074A

US1673074A - Method of and apparatus for forced-air heating

Info

Publication number: US1673074A
Application number: US214546A
Authority: US
Inventors: Houghtby George Titus
Original assignee: Individual
Current assignee: Individual
Priority date: 1927-08-22
Filing date: 1927-08-22
Publication date: 1928-06-12
Anticipated expiration: 1945-06-12

Description

June 12, 1928. 1,673,074

4 GT. HOUGHTBY METHOD OF AND APPARATUS FOR FORCED AIR HEATING F l Augi 1927 2 ShetsShe 1 June 12, 1928.

(5. T. HOUGHTBY METHOD OF AND APPARATUS FOR FORCED AIR HEATING 2 Sheets-Sheet Filed Aug. 22, 1927 Patented June 12, 1928.

UNITED STATES GEORGE TI TUS HOUGH'IBY, OF LONDON, ONTARIO, CANADA.

METHOD or AND ArrAnAT'U's Foal FORCED-AIR HEATING.

Application filed August 22, 1927. Serial No. 214,546.

In a warm air heating system, convection is the means by which heat is transferred from the heating surfaces of the furnace to the register and the number of heat units delivered in a given space of time is determined by the volume and temperature of the air that issues from it. Tests have shown that the average air temperatures at the register range from 120 to 220 F. depend ing upon the rate at which the fuel is consumed and the initial temperature of the air entering the heating zone of the furnace,

pound of air that passes into the room during the hour must contain 36 B. t. u. available for producing the desired heating effeet and it will therefore require 368 pounds of air hourly to equal the loss. If the air temperature at the register is 120 F. every pound of air that passes into the room during the hour will contain 12 B. t. u. available for producing the desired heating effect and instead of 368 pounds of air it will be necessary to supply 1100 pounds of air hourly to equalize the heat loss or three times as much air by weight must be supplied to the room if the temperature at the register is 120 F. as would be required-if the temperature is 220 In gravity warm air heating systems a single current enters the heating zone of the furnace and expands or becomes lighter in weight as its temperature rises, thereby producin an unbalanced condition on the warm and cold air sides and causing a displacement or circulation limited largely by the capacity of the intake and discharge. To offset these limitations it is customary to use a centrifugal fan for increasing the velocity head of the current but heretofore the use of the fan has been confined to the acceleration of this single air current and the air temperature at the register has been limited to the B. t. u.'from the heated sur faces of the combustion zone.

My present invention relates to a forced air heating system in which an air current is established through each of two zones. One of these zones is heated from the surfaces of the combustion chamber to a temperature which may exceed 220 F. and contain over 36 B. t. u.s per pound of air at the register, and the other zone may be heated, by the waste products' of combustion passing through the smoke pipe to a temperature which may exceed 120 F. and contains at least 12 B. t. u.s per pound of air at the register or this last mentioned zone may su ply a. current of fresh or cold air. The ve ocity head of each current is mechanically maintained by a centrifugal fan the speed of which is regulated to the required. capacity of the furnace. The fan comprises a rotor provided with two sets of blades each operating to create an accelerated current through its respective zone and with a diaphragm which effects the separation of the two currents untilexpelled by the fan beyond the rotational path of the blades, where they are mixed and combined into a singlecurrent.

In the construction shown in the drawings and hereinafter described. the fan blades of one set are hollow or tubular, their inner ends are bevelled or chisel shaped to form a central co noidal, recess around the hub, the bones of the blades are open atboth ends, and the inner ends of the bores communicate withthe recess. The other set con sists of web-shaped vanes extending radially from the hub and operating to draw the air into the recess and expelit through the hollow or tubular blades. Flanges extend latorally from the upper edges of the sides of each blade and flanges of adjacent blades are riveted, welded or otherwise secured together to form a diaphragm which connects and braces the. blades and separates the air currents at one side of the rotor from the air currents at the other side. An annular plate or ring overlies'and is secured to the top of the hollow blades and to the web shaped vanes for securing them together and ensuring their united rotation, and this annular plate or ring is formed with a central orifice co-axial with the conoidal recess. At one side-0f the diaphragm, the vanes create a current in the conoidal recess and expel it through the'hollow blades and at the other sidethe blades create a current which is separate from that in the recess until the two currents are expelled beyond the rotational path of the rotor.

For an understanding of the invention part of the furnace on the line 22, Fig. 1, v

reference is to beihad to the following description and to the accompanying drawings, in which:

Fig. 1 is a sectional plan view of the furnace, r Fig. 2 is a vertical'section otthe upper Fig. 3 is aplan view of the rotor partly in section on a larger scale than Figs. 1 and'2, r n

Fig. 4 is a vertical section on the line 4--1, Fig. 3,

Fig. 5 is a plan view of the fan hub,

Fig. 6 is a vertical section on the line 66, Fig. 5, I

Fig.7 is a perspective view of one of the fan blades,

Fig. 8 is a side elevation showing an alternative method of fan installation, and

Fig. 9 is a vertical section of the smoke pipe and a heater or drum surrounding it.

Like numerals of reference refer to like parts. throughout the specification and draw-' from a zone exterior ofthe turnaceand ineither'case is combined with the air from the other zone. In both of these Zones the movement of the air currents is accelerated by a fan which includes arotor compris ing a hub and two separated sets of blades,

each of which creates a current independently of the other set. f I

The fan shown in; the drawings comprises 'a set of hollow or tubular blades 4 and ahub consisting of a "sleeve 1 provided with jfour web-shaped arms 2 extending radially from it and a'lug 3 at the outer end of each arm. The bore 5 of each blade 4'is open at both ends for the circulation of the air through the blade, and the inner end of each blade is bevelled or chisel shaped. The blades are'assembled with the hubrafter the manner of the spokes of a wheel, as shown inFi'g. 3. and in this'assembly the bevelled or'chisel shaped ends of the blades abut'around the central sleeve 1 and form a conoidal recess 8. 'The inner end of the bore 5 of each blade communicates with the recess and the web-shaped arms 2 extend'from the-sleeve across the which separates the air currents at one side of the rotor from the air currents at the other side. An annular plate or ring 6 overlies the blades 4 and is secured to them a and to the lugs 3 for connecting the blades to'lugs 3 and this plate or ring is formed with a central aperture or orifice 7 overlying and of corresponding area to the recess 8. At the lower edge of each blade 4 is a curved or inclinedflange 9 extending radially from the sleeve part way to the periphcry of the rotor and laterally from the lower edge of the blade, for the purpose of efi'ectin'g an uplift of the air into the path of the blade during its revolution. The

. the two air currents to mixwhen expelled beyond the periphery of the rotor.

The fan housing or casing 10 contains two chambers 12 and 1i and the rotor revolves in the chamber 12. The chamber 14 is above the chamber 12 and has a sloping bottom 15 formed with a central aperture 16 and a downturne'd flange 17 entered through the central aperture '7 in the plate or ring 6.

The chambenll i has an inlet 18 connected 1 by a pipe -18 with a drum or heater 18 surrounding the smoke pipe 18 The heater or drum may consist of two telescopic sections which can be contracted for decreasing, or extended for increasing, its heating capacity.

The drum is provided with a damper controlled air intake 18 which may be connected with a cold air supply leading to the exterior of the building or toany other convenient location. The air circulates through the damper controlled intake to the heater or drum and through the inlet 18 to the chamber 14. Thi inlet'18 is provided with a balanced damper 19 which automatically opens under the pressure of the inf'lowing air during the operation of the tan and auto matically closes when the fan stops. An electric motor 20 is mounted'on the top of the housing or casing 10 and is provided with a motor shaft 21 which extends into and is'connected with the fan hub. but any other type of drive may be used. The fan is shown in 1 and 2 to be located above the heating surfaces of the furnace butit may be installed between the furnace and the registers or in any other part of the system, shown ,in Fig. 8, and used to temper anddistribute the air or to supply a current of fresh air taken from the exterior of the building and mix it with the heated air. The blades 1 of the fan during its operation, create a forced circulation of air from the heating zone or free airspace between the heated surfaces of the combustion chamber 30 and the casing 31 and expel it beyond the rotational path'of the fan and the webshaped arms or vanes 2 create a current into i in CAI

, these two currents into a single current within the fan housing.

Having thus fully described my invention what I claim as new and desire to secure by Letters Patent is:

1. The hereindescribed method of forced air heating which consists of simultaneously creating an air current in each of two separated zones, heating the air in at least one of the zones, maintaining the separation of the currents during the heating stage, expelling them from their respective zones, and combining them when expelled.

2. The hereindescribed method of forced air heating which consists of simultaneously creating an air current in each of two separated heating zones, heating the air in at least one of the zones, maintaining the separation of the currents during the heating stage, increasing their velocity head, expelling them from their respective zones, and combining them when expelled.

3. In an apparatus for forced air heating, the combination of a furnace having two separate heating zones. a centrifugal fan for creatinga current through each of the two separate zones. said fan having a rotor comprising a hub, a set of hollow blades open at both ends and shaped at their inner ends to form a recess around the hub. a set of vanes extending radially from the hub into the recess, and a diaphragm separating the air current at one side of the rotor from the air current at the other side, the blades creating at one side of the diaphragm an air current through one of the Zones and expelling it from the fan, and the vanes at the opposite side of the diaphragm creating an air current through the other zone into the recess and expelling it through the hollow blades to combine with the air current expelled by the blades. I

4. In an apparatus for forced air heating, the combination of a furnace having two separate heating zones. a centrifugal fan for creating a current through each of the two separate zones, said fan having a rotor comprising a hub, a set of hollow blades open at both ends and shaped at their inner ends to form a recess around the hub. a set of vanes extending radially from the hub into the recess, and a diaphragm separating the a r current at one one side of the rotor from the air current at the other side, the blades creating at one side of the diaphragm an air current through one of the zones and expelling it from the fang'a-n-d the vanes at the opposite side of the diaphra rn creating an air current through the ot'cr zone into the recess and expelling it through the hollow blades to combine with the air current expelled by the blades, and deflectors for retarding the re.- 7

tation of the air currents and causing the velocity head to build up as the rotor revolves.

5. In an apparatus for forced'air heating as claimed in claim 3, in which the rotor of the centrifugal fan is enclosed in a housing containing two chambers, in one of which the rotor revolves and is in communication with one of said zones, and the other of which is above the first mentioned chamber and is provided with an inlet in communication with the other zone and the recess.

6. In an apparatus for forced air'heating as claimed in claim 3 in which each blade is I provided with a radial flange extending laterally from its lower edge for effecting the uplift of the air into the path of the blade during the rotation of the rotor.

7 In an apparatus for forced air heating, the combination of a furnace having two separate heating zones, a centrifugal fan for creating a current through each of the two separate zones, said fan having a rotor comprising aset of blades for creating an air cur-,

rent at one side of the rotor through one of the zones and expelling it from the fan, and a set of vanes at the other side of the rotor for creating an air current through the other zone and expelling it to combine with the first mentioned current, and a diaphragm for maintaining the separation of the two currents until expelled.

8. In an apparatus for forced air heating, the combination of a furnace having two separate heating zones, a centrifugal fan for oreating a current through each of the two separate heating zones, said fan comprising a rotor having a set of hollow blades for creating, at one side of the rotor, an air current through one of the zones and expelling it from the fan, and a set of vanes at the other side of the rotor for creating an air current through the other zone and expelling it through the hollow blades to combine with the first-mentioned current.

9. In an apparatus for forced air heating, a

furnace having a free air space heated from the combustion zone. and a drum heated by the products of combust on, 1n combination with a fan comprising a rotor having two sets of blades separated by a diaphragm, one set of blades creating a current through said free air space, and the other set of blades creating a current through the drum, each set of blades increasing the velocity head of its respective current and expelling it from the fan to combine with the other current, and the diagram maintaining the separation of the two currents until expelled by the fan.

10. In an apparatus for forced air heating the combination of afurnace having two sepis heated in the other zone and expelled arate heating zones and a centrifugal fan through'the hollow blades to combine vwith 10 having a rotor comprising a set of hollow the first-mentioned current.

blades for creating at one side of the rotor an Dated at the city of London, in the county. air current Wl'llCll lS heated in one '01": the of Middles eX and Province'ot Ontario, Do-

zones and expelled by the blades from the minion of Canada, the thirteenth day o1 tan and a set of vanes for creatin gnt the August, 1927.

, other side of the rotor an air current Which GEORGE TITUS HOUGrHTBY.