U.S. patent number 3,861,198 [Application Number 05/303,631] was granted by the patent office on 1975-01-21 for fluid analyzer with self-cleaning viewing windows.
This patent grant is currently assigned to Gam Rad, Inc.. Invention is credited to James J. Shea.
United States Patent |
3,861,198 |
Shea |
January 21, 1975 |
FLUID ANALYZER WITH SELF-CLEANING VIEWING WINDOWS
Abstract
A turbidimeter or fluid analyzer having the light transmitting
windows maintained clean by apparatus directing a flow of fluid
thereupon.
Inventors: |
Shea; James J. (Dearborn
Heights, MI) |
Assignee: |
Gam Rad, Inc. (Detroit,
MI)
|
Family
ID: |
23172990 |
Appl.
No.: |
05/303,631 |
Filed: |
November 3, 1972 |
Current U.S.
Class: |
73/61.41;
137/238; 137/240; 250/239; 356/246; 356/441; 359/509 |
Current CPC
Class: |
G01N
21/15 (20130101); G01N 21/85 (20130101); Y10T
137/4245 (20150401); Y10T 137/4259 (20150401) |
Current International
Class: |
G01N
21/15 (20060101); G01n 021/26 (); G02b () |
Field of
Search: |
;137/240,238
;73/36,61R,DIG.11,355 ;350/63X ;251/118,61 ;356/208,246,207
;250/239,218 ;138/46,44,45 ;116/117C ;134/166C |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Cohan; Alan
Assistant Examiner: Miller; Robert J.
Attorney, Agent or Firm: Zwerdling, Maurer, Diggs &
Papp
Claims
I claim:
1. A fluid analyzer comprising an annular, elongated flow tube,
said tube having at least one window whereby the fluid can be
analyzed, and flow means operatively connected to said flow tube
for directing fluid flow across the surface of said window in said
tube whereby said surface of said window will be maintained clean,
said flow tube including means for transmitting the fluid to be
analyzed through a first passageway past said window whereby the
analyzed fluid can be viewed and with said flow means comprising
separate passage means for directing fluid across the surface of
said window via a second passageway separate from said first
passageway, said flow means comprising a different annular
elongated tube supported within said flow tube and defining with
said flow tube said first and second passageways.
2. A fluid analyzer comprising a flow tube, said tube having at
least one window whereby the fluid can be analyzed, and flow means
operatively connected to said flow tube for directing fluid flow
across the surface of said window in said tube whereby said surface
of said window will be maintained clean, said flow tube including
means for transmitting the fluid to be analyzed through a first
passageway past said window whereby the analyzed fluid can be
viewed and with said flow means comprising separate passage means
for directing fluid across the surface of said window via a second
passageway separate from said first passageway, said flow means
comprising shunt means for receiving a portion of the fluid to be
analyzed and directing that portion across the surface of said
window.
3. A fluid analyzer comprising a flow tube, said tube having at
least one window whereby the fluid can be analyzed, and flow means
operatively connected to said flow tube for directing fluid flow
across the surface of said window in said tube whereby said surface
of said window will be maintained clean, said flow means directing
fluid to be analyzed across the surface of said window.
4. The analyzer of claim 1 with said flow means transmitting all of
the fluid to be analyzed.
5. A fluid analyzer comprising a flow tube, said tube having at
least one window whereby the fluid can be analyzed, and flow means
operatively connected to said flow tube for directing fluid flow
across the surface of said window in said tube whereby said surface
of said window will be maintained clean, said flow means comprising
flow restrictor means located approximate to said window for
providing fluid flow at an increased velocity.
6. The analyzer of claim 5 with said flow restrictor means defining
a restricted passageway and with said tube adapted to transmit all
of the fluid to be analyzed through said restricted passageway.
7. The analyzer of claim 6 with said restricted passageway
terminating adjacent said window and communicating therewith a
substantially increased volume whereby the fluid flow will be
turbulent in the vicinity of the surface of said window.
8. The analyzer of claim 7 with said flow restrictor means
comprising a closed tube supported within said flow tube and
located to define said restricted passageway.
9. The analyzer of claim 7 with said flow restrictor means
comprising a generally conically shaped member located to define
said restricted passageway with the base downstream.
10. The fluid analyzer of claim 9 with said base having a contour
similar to the contour of the confronting surface of said flow
tube.
Description
SUMMARY BACKGROUND OF THE INVENTION
The present invention relates to turbidimeters and more
particularly to a turbidimeter having apparatus for cleaning the
light transmitting windows.
With the recent emphasis on pollution control the potential
applications for turbidimeters or fluid analyzers as fluid flow
monitors has increased. In some applications, however, the fluid to
be monitored or analyzed can be such as would deposit particles on
or eventually coat the windows; clearly the effectiveness of the
device could be maintained only through periodic cleaning. In the
present invention, this problem is solved by utilizing a flow of
fluid over the window to clean and/or insulate the window from
contamination.
Therefore, it is an object of the present invention to provide a
new and improved turbidimeter having means for maintaining the
light transmitting window clean.
In one form of the invention the window is maintained clean by
providing, in a sense, a curtain of water or other clean fluid,
different from the monitored or analyzed fluid, across the window
to maintain a thin protective film or barrier thereacross. Thus it
is another object of the present invention to provide a
turbidimeter of the above described type having apparatus for
providing a curtain or film of fluid, different from the monitored
fluid, across the light transmitting windows to maintain them
clean.
In another form of the invention, apparatus is provided to increase
the flow of the monitored fluid on the area adjacent the windows
and then to maintain the windows clean by the velocity of the fluid
or in a different form by turbulence. Thus it is another object of
the present invention to provide a turbidimeter having apparatus
for cleaning the light transmitting windows by using the monitored
fluid and by increased velocity across the windows and/or
turbulence at the windows.
It is still another general object to provide for an improved
turbidimeter.
Other objects, features, and advantages of the present invention
will become apparent from the subsequent description and the
appended claims, taken in conjunction with the accompanying
drawings, in which:
FIG. 1 is a longitudinal sectional view taken generally along the
lines 1--1 of FIG. 2 of a turbidimeter having apparatus for
providing a film of fluid across the transmitting windows, which
film of fluid is different from the fluid being analyzed;
FIG. 2 is a sectional view of a portion of the turbidimeter of FIG.
1 and taken generally along the lines 2--2 of FIG. 1;
FIG. 3 is a fragmentary view of a modified flow tube for a
turbidimeter similar to that of FIG. 1 having a construction for
providing a separate flow of fluid across the transmitting windows
which is the same fluid as that being analyzed;
FIG. 4 is a fragmentary view of a different, modified flow tube in
which all of the fluid to be monitored is directed through a
restriction adjacent the windows; and
FIG. 5 is a fragmentary sectional view of still another form of the
invention for providing a restriction adjacent the transmitting
windows.
Looking now to FIG. 1, a turbidimeter or fluid analyzer is
generally shown and is indicated by the numeral 10 and includes a
flow tube assembly 12 and a support housing 14. The tube assembly
12 includes a main outer tube 16 which has a flange 18 at its
outlet end and a threaded adaptor 20 secured to its inlet end. The
adaptor 20 receives the end of a pipe 22.
The main tube 16 has a necked down portion 24 intermediate its
ends, which necked down portion is provided with a plurality of
flats including flats 26 and 28 which facilitate the mounting of a
light source assembly 30 and a sensor assembly 32. The light source
assembly 30 includes a lamp 33 which can be energized in a suitable
source of electricity and the output of which can be sensed and
regulated via a regulator 34; regulator 34 can be of a type well
known in the art and hence the details thereof have been omitted
for purposes of simplicity. The lamp 33 is connected to transmit
its light through a lense assembly 36 and thence into the necked
down portion 24 of the flow tube 16 via a window assembly 38. The
window assembly 38 is connected to the flat portion 26 and includes
a window 40 which has its inner surface generally flush with the
flat portion 26.
As can be seen from FIG. 2, the flat portion 28 is at quadrature
with flat portion 26. Looking again to FIG. 1, the sensor assembly
32 is connected to a lense assembly 42 which in turn is connected
to a window assembly 44. The window assembly 44 is connected to the
flat portion 28 and includes a window 46 which has its inner
surface generally flush with the flat portion 28. The sensor
assembly 32 includes a suitable photoresponsive member and can be
connected to suitable output indicating apparatus (not shown)
whereby an indication of the turbidity of the fluid being analyzed
can be obtained. The output indicating apparatus can be of
construction well known in the art and hence a description thereof
has been omitted for purposes of simplicity.
As noted the turbidimeter 10, having the light source and
photosensitive member at a relative angle of 90.degree. operates on
the Tyndall Effect. It should be understood, however, that the
present invention is not limited to Tyndall Effect turbidimeters
but can be used generally with any turbidimeter or fluid analyzer
having a window exposed to the fluid being analyzed. A window
assembly 47 (FIG. 2) provides for pass through of the light from
source 30 and minimizes errors from reflected light from that
opposite wall.
An inner smaller diameter tube 48 has an enlarged end portion 50
which is snugly, sealingly held to the inside diameter of adaptor
20. The tube 48 extends generally up to the windows 40 and 46 and
is in direct communication with the pipe 22 such that the fluid to
be analyzed will be carried by the inner tube 48 and transmitted
into the main tube 16 at the windows 40 and 46 whereby the fluid
will be exposed for analysis via the light means 30 and sensor
means 32.
The inner tube 48 has a reduced diameter portion 52 which defines
an annular passageway 54 with the main tube 16; the inner tube 48
terminates in a reduced diameter end portion 56 which is located in
close clearance relation to the necked down portion 24 and defines
therewith a restricted passageway 58 which terminates just ahead of
the windows 40 and 46.
The end portion 56 is also provided with flats similar to the
reduced diameter portion 24.
An inlet pipe 60 is connected to the main tube 16 at a position to
communicate the annular passageway 54 and a source 62 of fluid. The
source 62 can be varied to vary the pressure of the fluid to
regulate the velocity of fluid across the windows 40 and 46. While
the preferred fluid from source 62 could be clean water any fluid
which would not adversely affect the analysis of the fluid from
pipe 22 can be used.
In operation, the clean fluid from source 62 is directed to flow
across the windows 40 and 46; the pressure of the clean fluid from
the source 62 is selected such that the velocity of clean fluid
from the restricted passage 58 is sufficient to provide a thin film
or curtain across the windows 40 and 46 to, in a sense, insulate
them from the fluid being analyzed. The pressure at the exit of
passageway 58 is also selected to be sufficiently high to assure
that the fluid to be analyzed, from pipe 22, will not back up into
passageway 54. Thus with the design of FIG. 1, the windows 40 and
46 will be maintained clean from contamination by the film or
curtain of clean water or other suitable fluid from source 62.
in the embodiments of FIG. 3-5 a separate fluid is not utilized and
the windows are maintained clean providing a curtain of film of the
fluid being analyzed at an increase in velocity in the area
adjacent the window so that the windows are maintained clean by a
scrubbing action caused by the increased velocity and/or by
turbulence. In the description of the embodiments of FIG. 3, 4 and
5, elements similar to like elements in the embodiment of FIG. 1
and 2 have been given the same numeral designation with the
addition of the letter postscripts a, b and c, respectively.
Looking now to FIG. 3, the need for fluid source 62 has been
eliminated and pipe 60a is now connected as a shunt from between
passageway 54a and pipe 22a. Thus, a portion of the fluid to be
analyzed flowing in pipe 22a is bypassed into passageway 54a while
the remainder flows through inner tube 48a. The remainder of the
construction is generally the same as that of FIG. 1. It is known
that the velocity of a fluid in a pipe is greater at the center
than at the outer extremity. However, by use of the fluid flow
through the restriction (similar to restricted passageway 58 of
FIG. 1) the velocity of the fluid is increased over what it would
have been if the outer tube 12a had been used alone in the
conventional manner. Thus, the fluid in passage 54a is discharged
adjacent the windows and at an increase in velocity; hence, the
windows are maintained clean by the scrubbing action of the film of
fluid flowing thereacross at an increase in velocity.
In the embodiment of FIG. 3 an auxiliary pump 67 is supplied in
line 60a to raise the pressure in line 60a to a level to provide
the desired flow through the restriction (similar to 58) for the
cleaning purpose noted. Alternatively a flow restriction could be
provided (in lieu of pump 67) in tube 50a to provide the necessary
differential in pressure between the fluid on tube 50a and that in
tube 60a to provide the desired flow through the restriction
(similar to 58).
Looking now to FIG. 4, again the fluid to be analyzed is used to
maintain the windows clean. Here the inner tube 48b is blocked at
opposite ends by plugs 64 and 66 and all of the fluid to be
analyzed is transmitted to the passageway 54b and pipe 60b. Now all
of the fluid to be analyzed is transmitted through the restricted
passageway 58b and flows across the windows 40b and 46b at an
increased velocity. In addition because the fluid from restricted
passageway 58b includes all of the fluid flowing through the main
tube 12b and the restricted passageway 58b opens abruptly into an
enlarged volume as defined by the necked down portion 24b adjacent
the windows 40b, 46b, there will be turbulence in this enlarged
volume. The turbulence and increase in velocity across the windows
40b, 46b will assist in maintaining the windows 40b, 46b clean.
In the embodiment of FIG. 5 the inner tube has been omitted and now
all of the fluid to be analyzed flows directly through the inner
tube 12c from the inlet pipe 22c. However, a flow restrictor 68 is
supported generally in the necked down portion 24c adjacent the
windows 40c, 46c and defines a restricted passageway 58c. In the
embodiment shown in FIG. 5 the flow restrictor 68 is generally
conically shaped and is supported in the main tube 12c via a
plurality of legs 70. The restrictor 68 terminates at its large or
base end in a plurality of flats 72 having an outer contour
generally similar to the contour of the confronting surface of the
flated, necked down portion 24c. The action of the restrictor 68 is
similar to that of the closed inner tube 48b of FIG. 4 in that it
provides for both an increase in velocity of fluid across windows
40c, 46c and also provides for turbulence in that area. This action
will assist in maintaining the windows 40c, 46c clean.
Note that the analysis or indication or turbidity is not affected
by the velocity of the fluid or by the turbulence of the fluid and
hence the apparatus of the embodiment of FIGS. 1-5 will not affect
the analysis being made.
Thus, in each of the embodiments shown, there is provided apparatus
for self-cleaning of the windows whereby the frequency of
maintenance can be reduced.
While it will be apparent that the preferred embodiments of the
invention disclosed are well calculated to fulfill the objects
above stated, it will be appreciated that the invention is
susceptible to modification, variation and change without departing
from the proper scope or fair meaning of the invention.
* * * * *