US3326278A - Closed circuit heat transfer devices - Google Patents

Description

June 20, 1967 c. COWAN CLOSED CIRCUIT HEAT TRANSFER DEVICES Filed Feb. 23, 1966 m'myrrve 194212-67 (av/rm I arr-02mg:

Patented June 20, 1967 3,326,278 CLOSED CIRCUIT HEAT TRANSFER DEVICES Robert C. Cowan, 578 I-Iarbison St, Winnipeg, Manitoba, Canada Filed Feb. 23, 1966, Ser. No. 529,415 2 Claims. (Cl. 165.105)

ABSTRAQT OF THE DISCLGSURE A closed circuit heating system having a boiler with radiating tubes extending upwardly therefrom through which vaporized fluid passes from the boiler to a sloping header tank and a condensate return conduit extending from the lower end of said sloping header tank to said boiler below the normal fluid level therein, said return conduit being shielded to prevent cosling thereof by air passing said radiator tubes.

My invention relates to new and useful improvements in heating devices, more specifically heating devices of the closed circuit type wherein fluid is heated in the boiler and vaporized, the vapour then passing through heat radiating tubes to a header tank, and the condensate then returning to the boiler.

The principal object and essence of my invention is to provide a device of the character herewithin described which improves the circulation of the vapour and condensate thereby increasing the efiiciency of the device.

Another object of the invention is to provide a device of the character herewithin described in wh'ch the condensate conveyor tubes are shrouded from the action of the air passing through the radiator formed by the vapour conveying tubes thus maintaining the returning condensate at a temperature higher than normal.

A yet further object of the invention is to provide a device of the character herewithin described in which the condensate in the header tank flows to one end of the header tank.

Another object of the invention is to provide a device of the character herewithin described which is simple in construction, economical in manufacture, and otherwise well suited to the purpose for which it is designed.

With the foregoing in view, and all those objects, purposes o-r advantages which may become apparent from consideration of this disclosure and specification, the present invention consists of the inventive concept embodied in the method, process, construction, arrangement of parts, or new use of the same, as herein particularly exemplified in one or more specific embodiments of such concept, reference being had to the accompanying figures in which:

FIGURE 1 is a side elevation, sectioned in part showing my device in situ with a conventional hot air system.

FIGURE 2 is a front elevation of my device per se.

FIGURE 3 is an end view of FIGURE 2.

FIGURE 4 is a sectional view along the line 4-4 of FIGURE 2.

In the drawings like characters of reference indicate corresponding parts in the different figures.

Proceeding therefore to describe my invention in detail, reference should first be made to FIGURE 1 in which illustrates a furnace casing generally having my device collectively designated 11 situated therewithin for the production of heat.

A fan 12 draws cold air through duct 13, through filters 14, and thence to duct 15 communicating with the furnace casing 10.

After passing through the heat radiating portion of my device 11, it passes to the hot air distribution duct 16 in the usual manner.

My device collectively designated 11, includes a boiler 17 having a substantially rectangular base 18 and a hemispherical upper wall 19.

Electric heating elements or similar heating means 20 extend into the lower portion of the boiler and may be connnected to a source of electrical energy (not illustrated) via terminals 21.

The boiler 17 is partially filled with fluid, preferably water, reference character 22 illustrating the water. level which is at all times above the heating element 20.

This provides a vapour space 23 above the water level, said vapour being steam formed by the heating of the water by means of a heating element, or elements 20.

A radiator collectively designated 24 surmounts the boiler 17 and comprises a pair of side plates 25 between which is situated a plurality of vapour conveying and heat radiating tubes 26. The lower ends 27 of these tubes communicating with the area 23 of the boiler and these tubes are preferably finned as shown at 28 to increase the heat radiating effect thereof, it being understood that the air passing through the furnace casing 1d, also passes by the finned tubes 26.

A header tank 2% surmounts the upper ends of these tubes and this header tank is substantially rectangular when viewed in plan. It comprises a pair of spaced and parallel longitudinal side walls 30 and a pair of spaced and parallel transverse end walls 31.

A base wall 32 and an upper wall 33 complete the header tank and the upper ends 34 of the tubes 26 extend through the base wall 32 and project above the level thereof as clearly shown in FIGURE 2. This is to prevent condensate forming within the header tank, from flowing downwardly through the tubes 26.

It will be noted that both the base wall 32 and the upper wall 33 of the header tank 29 slope downwardly from one end wall 31 towards the other end Wall so that condensate forming within the header tank, flows to the right-hand end Wall 31 (with reference to FIG- URE 2).

Adjacent the right hand end wall 31, I have provided a pair of condensate conveying ducts 35, the upper ends 36 of which are flush with the base wall 32 of the header tank and communicate therewith.

These ducts extend downwardly to the boiler and communicate with the interior thereof, the lower ends 37 of these ducts terminating adjacent the base 38 and below the fluid line 22.

In order to maintain the temperature of the condensate flowing down the tubes 35, at the h ghest possible temperature, I have provided a pair of baflles 39 situated at right angles to one another and extending from the base 32 of the header tank to the upper side 40' of the boiler.

These shroud the condensate conveying ducts 35 from the effect of the air passing through the radiator, it being understood that said air is moving in the direction of arrow 41.

The advantage of sloping the base 32 of the header from one side end to the other is to permit the condensate conveying duct to be situated at one end of the radiator and away from the tubes 26.

This prevents cool spots from occurring within the radiator, which cool spots have occurred previously when the return ducts have been centrally located.

Also by shrouding the condensate conveying ducts 35, the condensate running down these ducts will not cool down so fast and will be of a higher temperature than normal so that less time and heat energy is required to return the condensate up to the desired operating temperature.

This will result in a faster build up of heat in the boiler in a shorter time cycle thus improving the efliciency of the furnace.

I prefer to use a pair of condensate conveying ducts 35 so that the condensate is withdrawn more rapidly and danger of flooding the condensate return duct is eliminated.

Since various modifications can be made to the invention herein described Within the scope of the inventive concept disclosed, it is not intended that protection of the said invention should be interpreted as restricted to the modification or modifications or known parts of such concept as have been particularly described, defined, or exemplified, since this disclosure is intended to explain the construction and operation of such concept, and not for the purpose of limiting protection to any specific embodiment or details thereof.

What I claim as my invention is:

1. In a heat exchange device, the combination of a boiler adapted to be partly filled with fluid whereby to provide space for fluid vapour in the upper portion of the boiler, a set of vapour conveying and heat radiating tubes communicating with and extending upwardly from the top of said boiler, a header tank provided at the upper end of said tubes, said header tank being substantially rectangular when viewed in plan and including a pair of spaced and parallel longitudinal side walls and a pair of spaced and parallel transverse end walls, an upper wall and a base wall sloping downwardly from one transverse end wall towards the other transverse end wall, to facilitate the drainage of fluid concentrate towards said other transverse end wall, the upper ends of said tubes extending in said tank above the base wall thereof, and at least one condensate conveying duct extending from said header tank adjacent said one transverse end Wall to a point in the lower portion of said boiler below the normal level of fluid therein, whereby vapour condensate in the tank may gravitate through said duct into said boiler, and baflle means shrouding said condensate conveyor duct to reduce the cooling of said condensate conveyor duct.

2. The device according to claim 1 in which said baflle means shrouding said condensate conveying tube from the air passing by said vapour conveying and heat radiating tubes, comprises a pair of vertically situated plates extending at right angles from one another and extending in spaced relationship the length of said condensate conveyor tube between the upper end of said boiler and the base wall of said header tank.

References Cited UNITED STATES PATENTS 1,662,440 3/1928 Rushmore 165 1,898,571 2/1933 Prince -105 X 2,712,054 6/1955 King 2l9365 2,734,989 2/1956 Hoffman 219-365 X ROBERT A. OLEARY, Primary Examiner.

A. W DAVIS, Assistant Examiner.

Claims (1)

1. IN A HEAT EXCHANGE DEVICE, THE COMBINATION OF A BOILER ADAPTED TO BE PARTLY FILLED WITH FLUID WHEREBY TO PROVIDE SPACE FOR FLUID VAPOUR IN THE UPPER PORTION OF THE BOILER, A SET OF VAPOUR CONVEYING AND HEAT RADIATING TUBES COMMUNICATING WITH AND EXTENDING UPWARDLY FROM THE TOP OF SAID BOILER, A HEADER TANK PROVIDED AT THE UPPER END OF SAID TUBES, SAID HEADER TANK BEING SUBSTANTIALLY RECTANGULAR WHEN VIEWED IN PLAN AND INCLUDING A PAIR OF SPACED AND PARALLEL TRANSVERSE END WALLS, AN A PAIR OF SPACED AND PARALLEL TRANSVERSE END WALLS, AN UPPER WALL AND A BASE WALL SLOPING DOWNWARDLY FROM ONE TRANSVERSE END WALL TOWARDS THE OTHER TRANSVERSE END WALL, TO FACILITATE THE DRAINAGE OF FLUID CONCENTRATE TOWARDS SAID OTHER TRANSVERSE END WALL, THE UPPER ENDS OF SAID TUBES EXTENDING IN SAID TANK ABOVE THE BASE WALL THEREOF, AND AT LEAST ONE CONDENSATE CONVEYING DUCT EXTENDING FROM SAID HEADER TANK ADJACENT SAID ONE TRANSVERSE END WALL TO A POINT IN THE LOWER PORTION OF SAID BOILER BELOW THE NORMAL LEVEL OF FLUID THEREIN, WHEREBY VAPOR CONDENSATE IN THE TANK MAY GRAVITATE THROUGH SAID DUCT INTO SAID BOILER, AND BAFFLE MEANS SHROUDING SAID CONDENSATE CONVEYOR DUCT TO REDUCE THE COOLING OF SAID CONDENSATE CONVEYOR DUCT.

Images