US2259902A

US2259902A - Solar heater

Info

Publication number: US2259902A
Application number: US235471A
Authority: US
Inventors: Mccain John David
Original assignee: Individual
Current assignee: Individual
Priority date: 1938-10-17
Filing date: 1938-10-17
Publication date: 1941-10-21
Anticipated expiration: 1958-10-21

Description

J. D. M CAIN SOLAR HEATER Filed Oct. 17, 1938 F/GZ.

[NV EN TGR.

A TTORNE Y Patented Oct. 21, 1941 UNITED STATESfPATENT OFFICE 2,250.09: soua mm John David min, Phoenix, Aria. Application October 11, ms, Serial No. team (or. ire-s11) scum.

My invention relates to solar heaters of the type adapted to collect the rays of the sun and direct the concentrated rays to a focal point on an object to be heated.

One of the objects of my invention is to provide such a device of simple, rugged construction character in whichadiustment of the focal point is not critical and in which adjustment may be made to allow for the seasonal change in the apparent path of the sun easily and quickly.

A further object is to provide a device of this kind in which the concentrating lens may be easily replaceable in case it becomes damaged in use: and

A further object is to provide a device of the character mentioned in which a lens of novel type is combined with apparatus for receiving the heat concentrated and converting same into a form of energy which may be easily applied to useful work.

Other objects will appear hereinafter.

I attain the foregoing objects by means of the apparatus, device and mechanical constructions illustrated in the accompanying drawing in which Figure 1 is a side elevational view of my type of lens;

Figure 2, an end or edgewise view thereof;

Figure 3, a side elevation of the device adapted to utilize said lens for the production of vapor from fluids, or the like, with certain portions thereof shown in section to better illustrate their construction.

Similar numerals refer to similar parts in all views.

Considering first, the lens, attention is directed to Figures 1 and 2. The lens, or refractor, is made of cast and polished glass in the general shape of a ring, a section of which is uniformly convex. Thus formed, I have provided a continuously annular convex lens adapted to concentrate the suns rays striking its outer periphery within a semi-cylindrical focal area having an axis coinciding with that of the ring.

In use, this lens is positioned with its axis at right angles to the Plane of the ecliptic; that is, so that its central diametric plane coincides with the ecliptic and the apparent path of the tioned, only the upper portion of the lens is used at any one time. It might be presumed that it would be easier to construct an arcuate semicircular lens of this nature. However, I have found that it is more eflclent to construct a lens in circular form, as here illustrated. In this form it may be easier cast and ground that would be the case with semi-circular arcuate segments. The diameter of the lens ring is such that, with a given sectional convexity of the annular body of the lens, light will be focused within an area around the periphery of cylinder 8. As the sun moves from horizon to horizon, the focused rays move in an annular path, as indicated by numeral 4, around the central portion of this cylinder. Concentration of light rays 3 is effected principally by the convexity of the section I of the ring but secondarily -by the annular convex shape of the ring body. Therefore, it may be said that the focal area of the lens body lies within an annular space surrounding the axis of the ring 2. At any one time the point or area of concentrated light and heat is directed on one spot or portion of the surface of the generator cylinder. As the sun moves, this place of concentration moves accordingly around a selected portion of the cylinder. In order to maintain an even focus, the axis of the cylinder, therefore, must coincide with the axis of the ring. Further, the radius of the ring must. be proportioned so that, with a given (or predetermined) convexity of the ring section I, the focal area will lie approximately upon the surface of the generator cylinder. The generator, of course, may have a spherical shape or a semi-cylindrical shape rather than that shown. In all cases, however, it should have an annular surface, the axis of which coincides with the axis of the ring body. The position of this focal area, as generated for the entire ring, is indicated by numeral 4.

It is to be understood that the sun's rays are not concentrated to a fine point upon the surface of the generator within the focal area but only sufficiently to obtain the degree of heat required. In some instances, therefore, with a lens of the same proportions, a generator having a.

larger, or another having a similar cylinder may be used. The focal area in such cases, wouldv have a greater or less diameter depending upon the size of the generator cylinder, and broadly might be better termed as a. focal space surrounding the axis of the ring. The outer periphery of the ring is indicated by numeral 5, the inner sun from horizon to horizon. when thus posi- P ip y y numeral 8 and the relative convexity of these surfaces-shown in section at I in Figure 3.

Anadaption of this type of lens to one form of device is illustrated in Figure 3. Here numeral 8 indicates a closed metallic cylinder which may be termed a generator or boiler, having an outlet tube 8 at its upper and right hand and an inlet l axially positioned and extending from the right hand end into the body of the cylinder as indicated by dottedlines ii, to a position near the left hand end of the cylinder. This inlet or return pipe is provided with a check valve i2.

This cylinder is mounted on trunnions i4, supported in a yoke i5 near its right hand end and on an axially extending rod It at its left hand end. This rod is held by thumb adjusting nut and bolt I! in an arcuate slot [8 in the are shaped supporting bar IS. The lens 2 is positioned with its axis coinciding with that of generator cylinder 8 and supported on a frame 28 which, in turn, is supported on a sleeve 2| fitted around cylinder 8. This sleeve may have a comparatively loose fit around the cylinder and thus permit both longitudinal axial adjustment of the lens along the body of cylinder 8 as well as circumferential rotary movement of the lens when desired.

In order to control the amount of heat applied to cylinder 8 at the area of concentration 4, I have provided a cylindrical mask 22 of metal, or other suitable material, mounted on spokes 23 attached to a hub 24, and this, in turn, mounted on cylinder -8 to provide a sliding fit so that the entire mask assembly may be easily moved longitudinally on the cylinder by control rod 25, which may be connected by levers and rods or cables to any position desired for remote control.

When thus set up, the device may be positioned so that the axis of the ring is at right angles to the .plane of the ecliptic. The axis of the ring is perpendicular to the dotted line EE, which represents a plane bisecting the annular body of the ring. When the axis of the cylinder and ring is placed in a north and south position the plane E--E may be made to coincide with the ecliptic by varying the position of rod 8 in support l8. Thus the position of the lens may be adjusted to have the correct angular position necessary to maintain the proper focus according to the season. Liquid to be vaporized is then introduced into cylinder 8 through pipe Hi. This may be water which is desired to be converted into steam for the purpose of operating a machine or it may be liquid containing gas such as Freon to be driven oif under pressure and used for obtaining refrigeration. In either case, after boiling or vaporization, due to the heat applied to cylinder 8, at the focal point, vapor escapes through the outlet pipe 8 and condensed liquid is returned from a closed circuit through check valve I2 and inlet I 0, to the lower or left hand portion of cylinder 8.

aasaeoe When it is desired to reduce the action of the device while the sun is shining, a portion of the rays to be concentrated is cut ofl by moving the mask 2: in thedirection indicated by the arrow 28. Thus regulation may be eflected.

Aside from the use above illustrated and described, the device may be used to heat a semihorizontal portion of vent pipe leading from a room to be ventilated to the atmosphere. By heating a portion of this vent pipe with a lens of this type, a hot spot is created on the pipe. air therewithin expanded, and a draft created; all without the necessity of any moving parts whatever.