Infra-red radiation device

The present invention relates to an infra-red radiation device comprising a shell or reflector body and holders mounted on the ends thereof, and also holders for accommodating IR-lamps. Each shell or body includes a plurality of individual reflector parts comprising reflector plates preferably of parabola shape. The body holder comprises a web and a recumbent U-shaped element, located at the end of the body adjacent the open reflector side. The free leg of the U-shaped element includes a glass holder in which a glass plate can be inserted, to insulate IR-lamps from dust and dirt. The U-shaped element is provided with holes for screws. The holder or reflector and/or the body holder includes, or include, air gaps or holes intended for cooling air, which preferably cools the ends of the lamps.

FIELD OF THE INVENTION 
The present invention relates to an infra-red radiation device of the kind 
described more specifically in the preamble of claim 1. 
Such radiation devices are used in widely differing fields for widely 
differing purposes. 
SUMMARY OF THE INVENTION 
The present invention relates to a infra-red radiation device comprising a 
reflector body having mounted thereon holders for accommodating infra-red 
lamps. The reflector body is provided with means for conducting cooling 
air and for insulating the device against the surrounding air. 
The radiation device according to the present invention is intended 
particularly, although not exlusively, for drying and/or treating paper 
and other web-forming materials from which, for example, water is to be 
removed by evaporation. In this respect, high drying powers per unit of 
surface area are required if the treatment device is not to become 
excessively bulky and expensive. In addition, there is required a high 
energy efficiency, a high degree of reliability, and the possibility of 
servicing and maintaining the device in a ready and simple fashion. These 
requirements are caused by the desire to effect production, for example, 
on a paper machine practically continuously, without interruption, 
throughout the whole year. The most serious factors liable to cause 
disturbances in this respect are the particularly large amounts of dirt 
and dust generated and high air humidities. 
Consequently, the object of the present invention, particularly with a view 
to the aforesaid difficulties, is to provide an infra-red radiation device 
which will counter-act these problems to the greatest possible extent. 
This object is achieved in accordance with the invention by designing an 
infra-red radiation device of the kind mentioned in the introduction in a 
manner to obtain the characterizing features set forth in the 
characterizing clause of claim 1.

In the drawings identical or like elements are identified by the same 
reference numerals. 
In the drawings, the reference 1 identifies a shell or reflector body 
comprising, for example, two to five individual reflectors 9, 10, 11. The 
reflector body is intended to support a reflector plate or the like 2 for 
directing radiation 12 incident thereupon and other elements. 
Consequently, an intrinsically rigid multiple arrangement of reflectors 
guarantees that respective infra-red lamps 5 of the arrangement do not 
irradiate mutually adjacent lamps, which would otherwise shorten the 
useful life thereof. 
The reflector plates or the like 2 are mounted between projections 13, 14 
which extend towards one another from the free edges of each of the 
reflectors. In this way, the flexible plate is curved to a parabola 
configuration, although without abutting the inside of the associated 
reflector. This is effected with the aid of spacers 15, arranged at 
various locations, upon which the plates 2 can rest, although it is not 
necessary for the plates to lie against all of the spacers of a reflector. 
Apart from this, the inside of each of the reflectors is of an irregular 
form, i.e. it follows solely the conditional shape of the inserted plate, 
wherewith there is formed in conjunction with the spacers continuous air 
gaps, which afford valuable heat insulation. This reduces the otherwise 
high thermal load on the reflector body. In certain instances, the spaces 
between plate and reflector body may be filled with a heat insulating 
material. It will be understood that the profile shape of the reflector 
body conforms substantially to the whole contour of the inserted plates. 
The inside of respective reflector bodies is also characterized by planar 
surfaces 16 located on mutually identical levels and lying opposite one 
another at the transition region or juncture between the web and legs of 
the reflector bodies. As a result of these planar surfaces 16, holder 
means (not shown) can be mounted thereon when manufacturing the reflector 
bodies, which enables the web portions to be punched-out or recessed at 
the ends thereof, with the aid of a mechanical punch. This recessing is 
necessary in order to mount the holder means. The shell or reflector body 
according to the invention is most suitably extruded from aluminium or an 
aluminium alloy, which means that the required recesses at the ends of the 
reflector bodies of desired length cannot be pre-formed. Consequently, it 
has been necessary hitherto to mill out the desired recesses, resulting in 
higher working costs and longer working times. Arranged on the side of the 
web remote from the inside of the reflector body is a continuous, 
substantially C-shaped groove 17 which is open away from the reflector 
body and in which a lamp holder 6 or some other element can be secured, 
preferably with the aid of a screw or nut or like fastener. 
As illustrated in larger scale in FIG. 3, in a preferred embodiment of the 
invention there is arranged in the web or bottom transition region between 
the individual reflector bodies, preferably at each location, a 
longitudinally extending body mounting groove 18. As will be seen from the 
figure, the groove 18 is enclosed by a substantially ring-shaped wall 
describing an angle greater than 180.degree. in the peripheral direction, 
there being arranged at equal angular distances shoulders or like 
promontories 19 in which the thread of for example, self-tapping screws 
are readily able to form screw threads, so as to ensure a positive 
anchorage. These self-tapping screws or the like 26 serve to mount a body 
holder 3 in the manner illustrated in more detail in FIGS. 7-9. 
As will be seen from these figures, such a body holder extends over the 
whole width of a multiple reflector body and is provided in the transverse 
direction thereof with a lower continuous U-shaped element 28, the one leg 
of which extends into a U-shaped glass holder 20, while the other leg of 
said element merges with an upwardly extending web 29 terminated at its 
other end with a short, angular gripping flange 30. As will be seen from 
FIG. 7, the glass holder 20 serves to support the end of a glass plate 4, 
wherewith the open side of the reflector body is shielded against the 
ingress of dirt, and also protected against the risk of fire, such risk 
being created by the ingress of combustible substances. The glass holders 
20 enable glass plates to be inserted at right angles to the longitudinal 
direction of the reflector bodies. 
The holder 3 is mounted on transverse rails or bars 21 with the aid of the 
outwardly projecting U-shaped element 28, more specifically with the aid 
of a row of holes 22, 25 formed in the two legs of said element, through 
which screws 8 can be inserted from the side facing the glass plate 4. 
These screws carry firstly a shield for the ends 7 of respective lamps and 
hold the shield firmly on the inside of the leg of the U-shaped element 28 
merging with the web 29, at the same time as the screw-threaded portion of 
the screw enters a corresponding screw-threaded hole in the bar 21. The 
fact that the U-shaped element 28 projects outwardly in relation to the 
web 29 enables a plurality of reflector bodies to be mounted in mutually 
abutting relationship, end to end, on a common bar 21. Of the mounting 
holes the holes 25 adjacent the glass holder 20 are preferably provided 
with a larger diameter, enabling the heads of the screws 8 to pass 
therethrough. 
As will be seen from FIG. 10, the reflector bodies are arranged in the form 
of modules 23, for example beneath a hood 24. Air of suitable temperature 
is blown into the hood 24, in order to cool the reflector bodies and the 
ends of the lamps. In the majority of cases, the temperature of the ends 
of said lamps should not exceed 300.degree. C. As a result of the 
construction according to the invention, air is conducted particularly 
along a movement path 27, i.e. intensively past the ends of the lamps, the 
end shields 7 of respective lamps contributing to define said path. 
Finally, the air flows through holes 25 in a direction conditioned 
thereby. The air is heated herewith to a temperature of about 50.degree. 
C. and improves thereby the drying process as a result of its directional 
effect. Air is also conducted herewith through the protective glass 4. 
In a typical case, the temperature of the protective glass 4 will lie 
between 300.degree. and 400.degree. C., as a result of the infra-red 
radiation absorbed. This temperature has an intrinsic cleansing effect, 
since the most common binders used in the coating of paper are organic 
substances, for example cellulose filaments, latex and starch. These 
substances carbonize at temperatures above about 225.degree. C. 
The infra-red lamps 5 mounted in the lamp holders 6 can be readily 
replaced, by removing the screws 8, having a diameter of about 10 mm, 
whereupon the glass 4 can be displaced to one side and the lamp-end shield 
7 lifted. This will release the lamp from the lamp holder. 
In addition to conducting cooling air past the ends of the lamps, the 
lamp-end shields also serve to prevent reflected radiation from 
irradiating the ends of the lamps and therewith heating the same. Such 
heating of the lamp-ends would shorten the useful life of the lamp. 
The reflector plates or the like 2 comprise a highly reflective material 
capable of withstanding high thermal loads over long periods of time. 
Suitable materials in this respect are gold or ceramic material. The 
plates can be readily withdrawn from the reflector body, for example when 
replacing the same. As will be understood, an inward pressing from the 
free side of the reflector body is also possible. 
The aforedescribed embodiments illustrated in the figures of the drawings 
are only to be considered as nonrestricting embodiments, which can be 
modified and developed within the scope of the concept of the invention.