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.

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.

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.