U.S. patent number 3,796,541 [Application Number 05/190,704] was granted by the patent office on 1974-03-12 for disinfecting apparatus.
Invention is credited to Albert F. Gentil.
United States Patent |
3,796,541 |
Gentil |
March 12, 1974 |
DISINFECTING APPARATUS
Abstract
Apparatus for sequentially evaporating a liquid disinfectant and
a neutralizing agent at constant flow rates and feed level. The
apparatus includes sealed containers for the liquids to be
evaporated; the containers communicating with open evaporating
vessels via conduits which are provided with bevel-cuts at the ends
immersed in the evaporating vessels, valves positioned to control
the flow through the conduits, absorbent pads extending above the
level of liquid in the vessels, and a blower for directing a flow
of heated gas across the absorbent pads.
Inventors: |
Gentil; Albert F. (Saint-Maur,
FR) |
Family
ID: |
22702421 |
Appl.
No.: |
05/190,704 |
Filed: |
October 20, 1971 |
Current U.S.
Class: |
422/108; 137/454;
137/624.11; 261/DIG.65; 261/104; 422/292; 422/305 |
Current CPC
Class: |
A61L
2/204 (20130101); Y10T 137/86389 (20150401); Y10T
137/7501 (20150401); Y10S 261/65 (20130101) |
Current International
Class: |
A61L
2/20 (20060101); A61l 009/02 () |
Field of
Search: |
;21/74R,117,121-126,110
;261/99,104,107,142 ;137/453,454,624.11 ;239/39,42,44 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Wolk; Morris O.
Assistant Examiner: Davis; Stephen B.
Claims
1. Disinfecting apparatus comprising:
a first sealed container, said first container being adapted to be
charged with a first liquid solution to be evaporated;
a second sealed container, said second container being adapted to
be charged with a second liquid to be evaporated;
first open evaporating vessel means vertically displaced from said
first sealed container and adapted to receive liquid to be
evaporated therefrom;
second open evaporating vessel means vertically displaced from said
second sealed container and adapted to receive liquid to be
evaporated therefrom;
a first tubular member providing communication between the interior
of said first container and said first evaporating vessel means,
said first tubular member having a first end displaced from said
first container and extending into said first evaporating vessel
means, said first end of said first tubular member being provided
with a bevel-cut;
a second tubular member providing communication between the
interior of said second container and said second evaporating
vessel means, said second tubular member having a first end
displaced from said second container and extending into said second
evaporating vessel means, said first end of said second tubular
member being provided with a bevel-cut;
first normally closed valve means disposed in said first tubular
member;
second normally closed valve means disposed in said second tubular
member;
liquid absorbing means positioned in each of said evaporating
vessel means, said absorbing means extending above the level of
liquid permitted in said vessel means and becoming charged with
liquid from said vessel means by capillary action;
means for directing a flow of heated gas across said absorbing
means to evaporate liquid therefrom at a rate which will maintain a
balance between the evaporated volumes of the constituents of the
liquids in said first and second sealed containers; and
means for selectively opening said valve means in accordance with a
preselected schedule, said means for opening said valves also
energizing
2. The apparatus of claim 1 wherein said gas flow directing means
comprises:
3. The apparatus of claim 1 further comprising:
4. The apparatus of claim 3 wherein said pressure relief means each
comprise:
tube means extending between the top of the container and said
conduit
5. The apparatus of claim 1 wherein said means for directing heated
gas comprises:
electric resistant heater means positioned adjacent to said
evaporating vessel means; and
6. The apparatus of claim 5 further comprising:
7. The apparatus of claim 6 wherein said pressure relief means each
comprise:
tube means extending between the top of the container and said
conduit
8. The apparatus of claim 7 further comprising:
adjustable baffle means for directing the flow of gases emanating
from said
9. The apparatus of claim 1 further comprising:
adjustable baffle means directing the flow of gases emanating from
said
10. The apparatus of claim 9 further comprising:
11. The apparatus of claim 10 wherein said pressure relief means
each comprise:
tube means extending between the top of the container and said
conduit means downstream of said valve means.
Description
BACKGROUND OF THE INVENTION
1 Field of the Invention
The present invention relates to the vaporization of substances
within an enclosure. More specifically, the present invention is
directed to apparatus for evaporating liquids, such as formalin and
ammonia, at a constant flow rate and feed level. Accordingly, the
general objects of the present invention are to provide novel and
improved methods and apparatus of such character.
2 Description of the Prior Art
While not limited thereto in its utility, the present invention is
particularly well suited for use in the fumigation or disinfection
of closed rooms. The treatment of rooms which are to be disinfected
by fumigating trioxymethylene, which is the trimer of formic
aldehyde (formaldehyde), is known. In accordance with one prior art
technique, the disinfectant is liberated by heating dry
formaldehyde. This technique, however, has a number of
disadvantages. The principal disadvantage is that the released dry
product does not develop its full disinfection power except in the
presence of water-vapor. Also, the dissipated aerosol particles are
far too large to permit deep penetration of the vapors and this, in
turn, additionally results in a rapid precipitation of the
particles.
It is also known to volatilize formalin solutions for disinfection
purposes by heating. In the prior art such evaporation, however,
has not been performed in a continuous, regular and uniform manner
and polymerization of the formaldehyde may occur. Accordingly, an
individual entering a fumigated room which has been treated by
volatilizing formalin solution will usually be inconvenienced by
the fumes and vapors of formalin and/or ammonia remaining in the
room.
SUMMARY OF THE INVENTION
The present invention overcomes the above briefly discussed and
other deficiencies and disadvantages of the prior art by providing
for the evaporation of liquids, and particularly disinfectants, at
a constant flow rate and feed level. Apparatus in accordance with
the invention comprises at least one sealed container which
communicates, at its lower end, with a bevel-cut pipe immersed in
an evaporating vessel having absorbent elements arranged
therein.
In accordance with a preferred embodiment of the invention,
apparatus for disinfecting an enclosed space includes a first
container filled with a formalin solution which is to be vaporized
to disinfect the enclosure. The apparatus further comprises a
second container filled with a solution of ammonia which is to be
vaporized in the interest of neutralizing the formalin. The first
and second containers are each provided, at their lower ends, with
a bevel-cut pipe and a valve controlling the liquid flow is
disposed within such pipes. Each of the bevel-cut pipes is immersed
in a separate evaporating vessel; the evaporating vessels having
absorbent elements disposed therein and being associated with means
for causing the volatilization of the liquid.
BRIEF DESCRIPTION OF THE DRAWING
The present invention may be better understood and its numerous
objects and advantages will become apparent to those skilled in the
art by reference to the accompanying drawing wherein like reference
numerals refer to like elements in the several figures and in
which:
FIG. 1 is a schematic representation of a first embodiment of
apparatus for evaporating formalin and ammonia in accordance with
the present invention; the embodiment of FIG. 1 operating
automatically and being adapted for disinfecting an enclosure such
as a hospital ward;
FIG. 2 is a cross-sectional side view of a second embodiment of the
present invention installed in a heating or ventilating duct;
and
FIG. 3 is a view, partly in section, of a third embodiment of the
present invention in the form of a mobile unit.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference now to FIG. 1, a container 1, which may be charged
with a formalin solution, is provided with an upper spout through
which the container may be filled. The spout may, in turn, be
sealed by means of a cap 2. The embodiment of FIG. 1 further
comprises an evaporating vessel 5 which communicates with the
bottom interior of container 1 via a conduit 4. A solenoid operated
valve is positioned in conduit 4 so as to control the delivery of
the solution from the container to the evaporating vessel.
The evaporating vessel has an open top and is provided with an
absorbent pad or pads 6 which, in the manner well known in the art,
become charged with liquid delivered to vessel 5 by capillary
attraction. The lower end 7 of the conduit 4, that is the end which
extends into vessel 5, is cut at an angle as shown. By varying the
angle of the bevel-cut at the lower end of conduit 4 the level of
the solution in vessel 5 can be controlled in accordance with the
rate of evaporation from pads 6 to thereby maintain the correct
rate of absorption by the pads. Accordingly, vessel 5 will contain
only the amount of liquid required for complete impregnation of the
absorbent pads 6 and the refilling of the vessel will be maintained
in accordance with the rate of evaporation from the pads.
The evaporator includes, in addition to vessel 5 and pads 6, a
blower 8 and associated electric resistance heater 9. The blower
delivers ambient air past heater 9 and thus directs heated air
across pads 6 to enhance the rate of evaporation of the liquid from
the pads. Control over valve 3, blower 8 and heater 9 is exercised
by a program transmitter or timer 10 in the manner to be described
below; power being delivered to the valve, heater and blower from
the timer by respective electrical conductors 11, 12 and 13.
The apparatus of FIG. 1 further comprises a second container 14
which may be charged, by removal of sealing cap 15, with ammonia.
The outlet pipe 17 of container 14, which discharges into a second
evaporating vessel 20, is provided with a solenoid operated control
valve 16. Like vessel 5, vessel 20 is provided with absorbent pads
21 and the evaporation of solution absorbed by pads 21 is promoted
by means of a blower 18 and associated resistance heater 19. Valve
16, blower 25 and heater 19 are controlled by a second program
transmitter or timer 22 which is connected to the elements to be
controlled by conductors 23, 24 and 25.
In a typical operating cycle, container 1 is filled with a 40
percent formalin solution with a capacity of about 20 ml per
m.sup.3 of the volume of the room or other enclosure to be treated.
After container 1 has been charged the program transmitter 10 is
set to the required treatment. As a general rule, periods of up to
6 hours are required but longer periods of up to 24 hours may be
necessary to destroy certain viruses. If neturalization of the odor
of the formaldehyde is required or desired, as is usually the case,
container 14 will be charged with ammonia with a capacity of about
10 ml per m.sup.3 of enclosure volume and program transmitter 22
will be set to the required neutralizing time.
Operation of the apparatus of FIG. 1 is initiated by means of
closing an electric switch, not shown, to activiate the preset
program transmitters 10 and 22. The transmitter 10 will energize
the solenoid of valve 3 thus opening the valve and will
simultaneously start blower 8 and energize resistance heater 9. Air
heated to about 100.degree. C will be blown against the absorber
pads 6 and the evaporation of the aqueous solution of formalin from
vessel 5 will occur at a regular and constant rate maintaining the
correct balance between the evaporated volumes of formalin and
water.
At the end of the treatment period selected in the initial setting
of program transmitter 10, valve 3 will automatically be closed and
blower 8 and heater 9 deenergized. At this time, preset program
transmitter 22 will energize the solenoid of valve 16 thus
permitting the delivery of ammonia to vessel 20. Program
transmitter 22 will also simultaneously energize blower 18 and
resistance heater 19 for the prescribed neutralizing period.
It will be of interest to note that the rate of evaporation from
vessels 5 and 20 may be regulated to satisfy the required operating
conditions through selection of the number of pads 6 and 21 and the
surface areas of these pads. It will also be noted that care must
be taken to maintain a sufficient concentration of vapors at the
highest located point within the enclosure being treated. For very
large closed spaces the apparatus of FIG. 1 may be mounted on a
turntable to insure adequate and uniform treatment.
The embodiment of FIG. 1, as well as the embodiments of FIGS. 2 and
3, may be employed for evaporating solutions other than formalin
and ammonia and thus it is to be understood that these substances
have been mentioned by way of example only.
In order to obtain a more effective disinfection of an enclosure it
is often advantageous to preheat the enclosure to about
30.degree.C. Preheating the enclosure yields an excellent
efficiency of the formalin vapors and also reduces the quantity of
precipitates which may deposit on cold surfaces such as windows,
x-ray screens, etc. In the interest of preheating, the apparatus of
FIG. 1 includes a further blower 26 which recirculates air
preheated by an electric resistance heater 27; blower 26 and heater
27 operating under control of program transmitter 28.
Due to the volatile nature of ammonia and formalin solutions,
during a preheating period a fairly high vapor pressure may often
develop within containers 1 and 14. This high vapor pressure, in
turn, may cause the solutions to be ejected forcefully from the
lower ends of conduits 4 and 17 upon the opening of valves 3 and 16
under the control of their respective program transmitters 10 and
22. This forceful ejection of material may result in the
overflowing of vessels 5 and 20. In order to prevent such
overflowing, the containers 1 and 14 are provided with respective
pressure relief conduits 29 and 30 which provide communication
between the tops of the containers and respective conduits 4 and 17
downstream of the valves 3 and 16. Pressure relief conduits 28 and
30 provide permanent pressure relief whereby no vapor pressure will
build up in the receivers and the liquid levels in vessels 5 and 20
will thus remain stable precisely at the level fixed by the angle
of the bevel-cut of the ends of conduits 4 and 17.
Apparatus similar to that described above may, in addition to use
within rooms and other enclosures, be employed to inject gaseous
formalin and ammonia into ventilation or air condition ducts in the
interest of disinfecting these housings and various objects
positioned therein. Accordingly, with reference now being made to
FIG. 2, apparatus in accordance with the invention may be
incorporated into shafts and ducts of forced ventilation systems.
In FIG. 2 an evaporator 40, which includes absorbent pads 42, is
shown mounted from a duct 41. The apparatus includes movable flaps
43 and 43' mounted within duct 41 and controlled by movable arms or
levers 44, 44'. Levers 44 and 44' are displaced by means of an
external screw 45 and associated spindle 46. Fastener means 48, 48'
allow the removal of inspection doors 47 and 47' respectively thus
giving access to the evaporator elements 42 and the liquid supply
container 49.
A mobile unit in accordance with the present invention is shown in
FIG. 3. The embodiment of FIG. 3 comprises an evaporator unit 50
mounted on a carrier provided with rollers 51. The evaporator is
provided with a pair of containers, not shown, which may be charged
by removing respective caps 53 and 54. Evaporator 50 also includes
program timers 55A, 55B and 55C which respectively correspond to
program timers 28, 10 and 22 of the embodiment of FIG. 1. The
evaporator 50 of FIG. 3 is energized, either with or without
preheating, by means of a control switch 56.
Unit 50 is provided with outlets or discharge ports 57 and 58,
respectively for the vaporized formalin and ammonia, in its front
side. The outlets 57 and 58 are provided with directional baffles
which preferably are adjustable and which will normally direct the
gas flows upwardly. Unit 50 is also provided with a third outlet or
discharge port 59 for the preheated air; outlet 59 also being
provided with adjustable directional baffles.
The embodiment of FIG. 3 also includes a device for reducing
precipitation of the reaction products of formalin and ammonia.
This device is indicated at 60 and is also mounted on rollers 65.
Device 60 is electrically connected to the evaporator unit 50 and
is controlled by means of a timer switch. The timer switch will be
preset to cause device 60 to operate for a predetermined period of
time after the formalin treatment has been completed and before the
neutralization or ammonia treatment has been started. When device
60 is operative the air within the enclosure, which has been
activated with formalin, is aspirated by a fan 61, as indicated by
arrows 62, and passes through a bed or layer 63 of activated carbon
or other material capable of binding the formalin. In most cases,
if fan 61 of device 60 has been operated for a sufficiently long
time, only a very small quantity of ammonia will be required for
neutralization.
It is noteworthy that apparatus in accordance with the present
invention can be mounted, if required for special application,
within a hermetically enclosed space which may or may not have an
exhaust port for discharging the gases resulting from the
evaporation to the atmosphere.
While preferred embodiments have been shown and described, various
modifications and substitutions may be made thereto without
departing from the spirit and scope of the invention. Accordingly,
it is to be understood that the present invention has been
described by way of illustration and not limitation.
* * * * *