Note: Descriptions are shown in the official language in which they were submitted.
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OPTICAL RADIATION SENSOR DEVICE AND
USE IN A RADIATION SOURCE MODULE
TECHNICAL FIELD
In one of its aspects, the present invention relates to an optical radiation
sensor device. In another of its aspects, the present invention relates to a
radiation source module comprising a novel optical radiation sensor device.
BACKGROUND ART
Optical radiation sensors are known and find widespread use in a number
of applications. One of the principal applications of optical radiation
sensors is
in the field of ultraviolet radiation fluid disinfection systems.
It is known that the irradiation of water with ultraviolet light will
disinfect
the water by inactivation of microorganisms in the water, provided the
irradiance
and exposure duration are above a minimum "dose" level (often measured in
units
of microWatt seconds per square centimetre). Ultraviolet water disinfection
units
such as those commercially available from Trojan Technologies Inc. under the
tradenames UV700 and UV8000, employ this principle to disinfect water for
human consumption. Generally, water to be disinfected passes through a
pressurized stainless steel cylinder which is flooded with ultraviolet
radiation.
Large scale municipal waste water treatment equipment such as that
commercially available from Trojan Technologies Inc. under the trade-names
UV3000 and UV4000, employ the same principal to disinfect waste water.
Generally, the practical applications of these treatment systems relates to
submersion of treatment module or system in an open channel wherein the
wastewater is exposed to radiation as it flows past the lamps. For further
discussion of fluid disinfection systems employing ultraviolet radiation, see
any
one of the following:
United States Patent 4,482,809,
United States Patent 4,872,980,
United States Patent 5,006,244,
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United States Patent 5,418,370,
United States Patent 5,539,210, and
United States Patent 5,590,390.
In many applications, it is desirable to monitor the level of ultraviolet
radiation present within the water under treatment. In this way, it is
possible to
assess, on a continuous or semi-continuous basis, the level of ultraviolet
radiation, and thus the overall effectiveness and efficiency of the
disinfection
process.
It is known in the art to monitor the ultraviolet radiation level by
deploying one or more passive sensor devices near the operating lamps in
specific
locations and orientations which are remote from the operating lamps. These
passive sensor devices may be photodiodes, photoresistors or other devices
that
respond to the impingent of the particular radiation wavelength or range of
radiation wavelengths of interest by producing a repeatable signal level (in
volts
or amperes) on output leads.
Conventional optical radiation sensors, by design or orientation, normally
sense the output of only one lamp, typically one lamp which is adjacent to the
sensor. If it is desirable to sense the radiation output of a number of lamps,
it is
possible to use an optical radiation sensor for each lamp. A problem with this
approach is that the use of multiple sensors introduces uncertainties since
there
can be no assurance that the sensors are identical. Specifically, vagaries in
sensor
materials can lead to vagaries in the signals which are sent by the sensors
leading
to a potential for false information being conveyed to the user of the system.
Accordingly, it would be desirable to have a radiation source module
comprising an optical sensor which could be used to detect and convey
information about radiation from a number ofradiation sources thereby
obviating
the need to use multiple optical radiation sensors.
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DISCLOSURE OF THE INVENTION
It is an obj ect of the present invention to provide a novel optical radiation
sensor which obviates or mitigates at least one of the above-mentioned
disadvantages of the prior art.
It is another object of the present invention to provide a novel radiation
source module which obviates or mitigates at least one of the above-mentioned
disadvantages of the prior art.
Accordingly, in one of its aspects, the present invention provides, an
optical radiation sensor device for detecting radiation in a field comprising:
a radiation collector for receiving radiation from a predefined arc around
the collector within the field and redirecting the received radiation along a
predefined pathway; and
a sensor element capable of detecting and responding to incident radiation
along the pathway.
In another of its aspects, the present invention provides a radiation source
assembly comprising a protective sleeve containing: (i) at least one radiation
source, and (ii) a radiation sensor device for detecting radiation in a field,
the
sensor device comprising: a radiation collector for receiving radiation from a
predefined arc around the collector within the field and redirecting the
received
radiation along a predefined pathway; and a sensor element capable of
detecting
and responding to incident radiation along the pathway.
In yet another of its aspects the present invention provides a radiation
source module comprising a frame having a first support member; at least one
radiation source assembly extending from and in engagement (preferably sealing
engagement) with a first support member, the at least one radiation source
assembly comprising at least one radiation source and a radiation sensor
device
for detecting radiation in a field, the device comprising: a radiation
collector for
receiving radiation from a predefined arc around the collector within the
field and
redirecting the received radiation along a predefined pathway; and a sensor
element capable of detecting and responding to incident radiation along the
pathway.
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In another of its aspects, the present invention provides a fluid treatment
system comprising an array of radiation sources for generating a field of
radiation, the array of radiation sources further comprising a radiation
sensor
device for detecting radiation in the field of radiation, the sensor device
comprising: a radiation collector for receiving radiation from a predefined
arc
around the collector within the field of radiation and redirecting the
received
radiation along a predefined pathway; and a sensor element capable of
detecting
and responding to incident radiation along the pathway.
Thus, the present inventors have discovered an optical radiation sensor
having a radiation collector for incident radiation which can collect and
redirect,
as appropriate, incident radiation from a number of radiation sources to a
single
sensor and convey information about the radiation output of the plurality of
radiation sources via a single radiation sensor. Preferably, this is achieved
by
having a radiation collector at an end of the radiation sensor which has a
concave
surface or a convex surface. Preferably, if a concave surface is used, the
surface
additionally comprises a reflective coating to enhance collection of
radiation.
As used throughout this specification, the term "concave surface" is
intended to mean a surface of a radiation collector which extends into the
body
of the collector (generally, the surface would protrude proximally with
respect to
the sensor element). Further, as used throughout this specification, the term
"convex surface" is intended to mean a surface of the radiation collector
which
protrudes out of the collector body (generally, the surface would protrude
distally
with respect to the sensor element).
Thus, the radiation collector in the present optical radiation source device
serves to gather or collect radiation from a predefined arc around the
collector and
redirect this radiation toward the radiation sensor. When the collector is in
the
form of a concave surface, a mirror effect may be used to reflect the
radiation
toward the sensor whereas when the collector is in the form of a convex
surface,
the incident radiation is refracted, internally reflected or diffused toward
the
radiation sensor. Preferably, the predefined arc around the collector is a
360° arc
although, in some cases, it may be useful and even advantageous to have a
single
arc of less than 360° or a number of arcs less than 360°C
contained within the
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field of radiation. Those of skill in art will recognize that the it is not
necessary
for the predefined arc to be coterminous with the arc of the field of
radiation at
the plane of radiation incidence.
In a further preferred embodiment, the sensor device is oriented with
respect to an elongate radiation source such that the predefined arc referred
to
above is in a plane which is substantially transverse to the longitudinal axis
of the
radiation source.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the present invention will be described with reference to
the accompanying drawings, wherein like numerals denote like elements and in
which:
Figure 1 illustrates a schematic of an array of radiation source assemblies
in partial section including a radiation source assembly in accordance with
the
present invention;
Figure 2 illustrates a schematic of a cross-sectional view of an array of
radiation source assemblies including a radiation source assembly in
accordance
with the present invention; and
Figure 3a-3h each illustrate an end view and side elevation view of a
number of embodiments of radiation collectors useful in the present invention.
BEST MODE FOR CARRYING OUT THE INVENTION
With reference to Figure 1, there is illustrated a trio of radiation source
assemblies 120,130,140. These radiation source assemblies could be contained
in a radiation source module such as the ones described in the United States
patents referred to hereinabove and/or in the radiation source module
described
in copending United States patent application S.N. 09/258,142 (Traubenberg et
al.).
Radiation source assembly 120 comprises a radiation source 122 disposed
within a protective sleeve 124.
Radiation source assembly 130 comprises a radiation source 132 disposed
within a protective sleeve 134.
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Radiation source assembly 140 comprises aradiation source 142 disposed
within a protective sleeve 144.
As will be apparent to those of skill in the art, radiation source assemblies
120 and 140 are similar in construction.
Radiation source assembly 130 also comprises an optical radiation sensor
150. Optical radiation sensor 150 comprises a radiation collector 152
connected
to a sensor photo-diode 154. Sensor photo-diode 154 is connected to a housing
156. Emanating out of housing 156 is an electrical cable 158. The sensor photo-
diode or other sensor material may be chosen from conventional sensors
materials. For example, a suitable sensor material is commercially available
from
UDT Sensors Inc. (Hawthorne, California)..
Disposed between optical radiation sensor 150 and radiation source 132
is a radiation shield 180. Radiation shield 180 serves to block radiation from
radiation source 132 being detected by radiation sensor 150.
Radiation collector 152 comprises a concave surface 153. Concave
surface 153 has disposed thereon a specularly or diffuse reflective material
156
(e.g., a TeflonTM coating) which serves to reflect incident radiation
impinging
thereon toward sensor photo-diode 154. Since radiation collector 152 is a
solid
body, it is preferred that it be constructed from a radiation transparent
material
(e.g., quartz and the like).
With reference to Figure 2, there is illustrated, in schematic an array of
radiation source assemblies 120 and 140 surrounding radiation source assembly
130. As illustrated, a portion of the radiation emanating from radiation
source
assemblies 120,140 will be that depicted by the dashed arrows in Figure 2.
This
radiation will impinge on reflective material 155 on concave surface 153 and
be
reflected toward sensor photo-diode 154. In this manner, optical radiation
sensor
150 may be viewed as a "360 ° sensor" in that it can receive and detect
radiation
from a substantially 360° plane (2-dimensional) or conoid (3-
dimensional)
around the collector. This constitutes a significant advance in the art in
that the
use of multiple sensors can be avoided.
With reference to Figure 3a, there is illustrated an enlarged view of
radiation collector 152 shown in Figure 1. Again, it is useful to coat the
concave
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surface with a reflective material that will reflect incident radiation toward
the
photo-diode. As illustrated radiation collector 152 in Figure 3a may be
constructed from solid quartz and is attached directly to the photo-diode
(154).
With reference to Figures 3b-3h, there are illustrated a number of alternate
embodiments for radiation collector 152 illustrated in Figures 1 and 3a.
Figure 3b is a modification of the embodiment of Figure 3a wherein the
radiation collection and reflection element is not directly connected to the
photo-
diode. In other words, in the embodiment illustrated in Figure 3b, the
radiation
collection and reflection element is remote from the photo-diode. Otherwise,
the
operation of the radiation collector in Figure 3b operates in the same manner
as
that described hereinabove for the radiation collector of Figures 1-2.
The radiation collector illustrated in Figures 3c-3g share the feature of
having a collector with a convex surface. In this instance, a reflective
coating is
not required. Rather, incident radiation on the convex surface of the
collector is
redirected to the photo-diode by refraction, reflection and/or both (i.e., a
"prism
effect"). In essence, Figures 3c-3g illustrate that the particular shape of
the
convex surface of the radiation collectors not particularly restricted
provided that
the appropriate refraction or "prism effect" can be achieved to redirect
incident
radiation toward the photo-diode. Generally, if the cross-section of the
radiation
collector parallel to a plane of incident radiation is circular (e.g., as
shown in
Figures 3a-3e), the radiation collector will have a radiation collection arc
of
substantially 360°. Generally, if the cross-section of the radiation
collector
parallel to a plane of incident radiation is polygonal (e.g., pentagonal as
shown
in Figure 3f, octagonal as shown in Figure 3g, triangular as shown in Figure
3h
and the like), the radiation collector will have one or more radiation
collection
arcs of less than 360°.
While the present invention has been described with reference to preferred
and specifically illustrated embodiments, it will of course be understood by
those
of skill in the arts that various modifications to these preferred and
illustrated
embodiments may be made without the parting from the spirit and scope of the
invention. For example, while the present invention has been illustrated with
reference to radiation source modules similar in general design to those
taught in
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United States Patents 4,872,980 and 5,006,244, it is possible to employ the
present radiation source assembly in a module such as the one illustrated in
United States Patents 5,418,370 , 5,539,210 and 5,590,390 - i.e., in a module
having a single support for one or more elongate source assemblies extending
therefrom. Further, it is possible to em ploy the present radiation source
assembly in a fluid treatment device such as those commercially available from
Trojan Technologies Inc. under the tradenames UV700 and UV8000. Still
further, while, in the embodiments illustrated and described above, the
optical
sensor is disposed at the end of the protective sleeve opposite the end where
electrical connections for the lamp are located, it possible to locate the
optical
radiation sensor at the same end as the electrical connections for the lamp
thereby
allowing for use of the protective sleeve having one closed end. Still
further, it
is possible to utilize an optical radiation source sensor disposed between two
radiation sources, all of which are disposed within a protective sleeve. Still
further it is possible to modify radiation collector 152 in Figures 1 and 3a
so that
the reflective coating is in a number of bands thereby modifying the collector
to
have one or more radiation collection arcs less than 360°. Other
modifications
which do not depart from the spirit and scope of the present invention will be
apparent to those of skill in the art.
