Apparatus and method for cleaning

An apparatus and a method for cleaning a device using ozonated water.

BACKGROUND OF THE INVENTION 
The present invention relates to an apparatus and method for cleaning and 
disinfecting a machine or device. For example, in the past, the standard 
method for cleaning a dialysis machine entailed delivering a solution of 
cleaning chemicals, such as an acid or base solution, a detergent, or an 
enzyme, into the dialysis machine and running the cleaning solution 
through the dialysis machine until any contaminants, such as blood, were 
removed from the machine, and all pathogens were killed. To prevent any 
traces of the cleaning chemical from being left in the dialysis machine, 
which would contaminate the next patient's blood, the dialysis machine had 
to be rinsed several times with water before the next dialysis procedure 
could be performed. 
The standard method of cleaning a dialysis machine, while satisfactory to 
the extent of producing a clean dialysis machine, has a number of 
disadvantages associated with it. One significant problem is the amount of 
time required to complete one cleaning procedure, which is approximately 
an hour. A technician must be present to operate the process, so this 
process is expensive in terms of labor costs. Also, the chemicals are 
expensive, and large amounts of water are used, which is also expensive, 
both in terms of the cost of the water and in terms of the cost of 
treating the water which leaves the machine. Also, since the dialysis 
machine cannot be used while it is being cleaned, a long cleaning cycle 
severely limits the amount of time a machine can be used during a day, 
thereby limiting the number of patients that can be served and the income 
that can be generated from using the machine. 
Another problem occurring with the standard method of cleaning a dialysis 
machine is the disposal of the cleaning solution after the cleaning 
process is completed. The used cleaning solution is often considered to be 
a toxic chemical requiring special disposal. Another problem with the 
standard method of cleaning a dialysis machine is that, if any traces of 
the cleaning chemicals are left in the machine, they can end up in the 
next patient's blood stream, perhaps harming the patient. 
SUMMARY OF THE INVENTION 
It is an object of the present invention to provide a fast method of 
cleaning a machine or device in order to reduce the "down time" of the 
machine or device and to reduce the labor costs associated with cleaning 
the machine or device. 
It is a further object of the present invention to provide a method of 
cleaning a machine or device without using solutions of toxic chemicals. 
It is a still further object of the present invention to provide a cleaning 
method using a cleaning solution which does not leave any residue of a 
toxic chemical on a machine or device being cleaned. 
It is another object of the present invention to provide a cleaning method 
that does not require extensive use of water for rinsing a machine or 
device after the machine or device has been cleaned. 
It is yet another object of the present invention to provide a cleaning 
method that does not require extensive purification of the rinse water 
after a machine or device has been rinsed. 
Accordingly, the present invention provides an apparatus and method for 
fulfilling the above objectives. 
The present invention uses ozonated water as a cleaning agent instead of 
using cleaning solutions. The ozonated water disinfects and cleans quickly 
and without leaving any residue, because the ozone quickly converts to 
oxygen and goes into the atmosphere. Thus, little or no rinsing is 
required after using the ozonated water to clean a machine or device. 
While the use of ozone to purify water is well known, ozonated water has 
not been used in the past to disinfect a machine or a device.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
The cleaning apparatus 10 of the present invention is shown in FIGS. 1-3. 
The apparatus 10 has a water inlet 12, a tank 20 for holding water, a 
first pump 16 having an inlet side 16a and an outlet side 16b, a second 
pump 18 having an inlet side 18a and an outlet side 18b, an ozone 
generator 26, and a water outlet 14. A float 22 is located inside the tank 
20, buoyantly riding atop a water level 80, which is shown in phantom in 
FIG. 2. The tank 20 is vented to the atmosphere by an opening 36 in the 
top face 20a of the tank 20, as seen in FIG. 1. A first Y-shaped water 
conduit 40 is mounted to the top of the tank 20. A first leg 40a of the 
conduit 40 is connected to the water inlet 12 through a pipeline 50 
equipped with a solenoid valve 24, while a second leg 40b of the conduit 
40 is connected to a Venturi tube 28 through a line 58. A second Y-shaped 
water conduit 42 is mounted to the bottom of the tank 20. A first leg 42a 
of the conduit 42 is connected to the inlet side 18a of the second pump 18 
by a line 54, while a second leg 42b of the conduit 42 is connected to the 
inlet side 16a of the first pump 16 by a line 52. The ozone generator 26 
has an air filter 30 and a pressure switch 32 and is connected to the 
Venturi tube 28 by a line 60. The Venturi tube 28 is also connected to the 
outlet side 16b of the first pump 16. The outlet side 18b of the second 
pump 18 is connected to the water outlet 14 by a line 62 equipped with a 
pressure gauge/bypass valve 34. There is a bypass path from the line 62 
through the pressure gauge/bypass valve 34 through bypass line 56 back to 
the tank 20. As best seen in FIG. 3, the cleaning apparatus 10 includes an 
electric box 70, an on/off switch 72, a timer 74, a counter 76, and a red 
light 78. The apparatus 10 is also equipped with rear wheels 11, front 
legs 13, and a handle 15. The path from the leg 42b at the bottom of the 
tank 20 through the line 52, through the pump 16, through the Venturi tube 
28, through the line 58, and back into the tank 20 is referred to as an 
ozonation loop, because the water from the tank 20 is ozonated as it 
passes through this loop. 
The operation of the cleaning apparatus 10 can best be understood by 
reference to FIG. 2. Before the apparatus 10 is used, the tank 20 is 
supplied with water from a water supply (not shown). For best results, 
purified water, such as from a reverse osmosis machine, should be used. 
After the water supply is connected to the inlet 12 by some means, such as 
a hose or a pipe, and the water supply is turned on, water from the water 
supply will enter the apparatus 10 at the inlet 12 and will flow through 
the line 50 and leg 40a into the tank 20. The water will flow through the 
tank 20 until it fills lines 52, 54, and 56, and then the water will begin 
filling the tank 20. Then, the water level 80 in the tank will rise until 
the float 22 reaches a predetermined level, at which point the float 22 
activates the solenoid valve 24 at the water inlet 12. The solenoid valve 
24 then closes off line 50 and stops the flow of water into the tank 20. 
When an operator turns on the apparatus 10 by flipping the on/off switch 
72, the first pump 16 and the ozone generator 26 are turned on. The first 
pump 16 begins pumping water from the tank 20 through the line 52 through 
the Venturi tube 28, where the water is mixed with ozonated air from the 
ozone generator 26, through the line 58, and back into the tank 20. At the 
same time, the ozone generator 26 begins to take in air through the air 
filter 30, as indicated by arrow 31. The air is filtered to remove 
contaminants, is dehumidified, and then the ozone generator 26 converts 
the oxygen in the air to ozone by passing an electric arc through the air, 
in a known process. Ozone exits the ozone generator 26 through the line 60 
and enters the Venturi tube 28. The Venturi tube 28 provides a reduced 
diameter in the water flow path, which creates a vacuum that pulls the 
ozonated air into the water flow path and mixes the water and the ozonated 
air in a well-known manner. Thus, because the first pump 16 is 
continuously recirculating water between the tank 20 and the ozone 
generator 26, the water in the tank 20 becomes ozonated. 
When the pressure switch 32 associated with the ozone generator 26 detects 
a pressure change which indicates that ozone is being drawn into the 
Venturi tube 28, the pressure switch 32 activates the second pump 18. The 
second pump 18 begins to take water from the tank 20 through the line 54 
and to pump this water to the outlet 14 via the line 62. This causes the 
water level 80 in the tank 20 to go down, which causes the float 22 to 
open the solenoid valve 24, thus allowing water from the water supply to 
flow into the tank 20, thus keeping an adequate supply of water coming to 
the apparatus 10. It will be appreciated that the water being pumped to 
the outlet 14 by the second pump 18 will not be ozonated at first, since 
the water standing in the line 54 will be pumped out first, but the water 
being pumped to the outlet 14 will be ozonated water once the pump 18 
begins to receive water from the tank 20, since ozonated water has now 
been pumped into the tank 20. 
The pressure gauge 34 monitors the pressure of the water flowing through 
the line 62. To ensure that the pressure of the water exiting outlet 14 
does not exceed rated levels, the pressure gauge 34 includes a bypass 
valve which will be opened whenever the water in the line 62 reaches a set 
pressure. When opened, the bypass valve in the gauge/valve 34 sends some 
of the water flowing through the line 62 into the bypass line 56, and back 
into the tank 20. 
It has been found through testing that the use of two separate pumps is 
preferable to the use of a single pump, because a single pump was unable 
to maintain the proper outlet pressure for water passing through the 
outlet 14. Also, by using one pump solely for ozonating the water in the 
tank 20, the embodiment described herein ensures constant circulation of 
ozonated water to the tank 20. 
By reference to FIG. 1, a method for the use of the preferred embodiment of 
the cleaning apparatus 10 to clean a device, such as the dialysis machine 
100, can be understood. An operator moves the apparatus 10 into the 
desired position by pushing down on the handle 15 and tilting the cleaning 
apparatus 10 backwards so that the weight of the apparatus 10 is taken off 
of the legs 13 and placed entirely upon the wheels 11, which makes the 
apparatus 10 easy to roll into place. When the apparatus 10 is in the 
desired position, the operator merely tilts the apparatus 10 forward until 
the legs 13 contact the ground. A hose 64 is used to carry ozonated water 
from the outlet 14 of the apparatus 10 into the dialysis machine 100. The 
ozonated water flows along an enclosed liquid pathway 102, which is shown 
in phantom, inside the dialysis machine 100, removing contaminants and 
disinfecting the interior of the pathway 102. The ozonated water and 
associated impurities from the dialysis machine 100 exit through a liquid 
outlet 66 and go to a drain (not shown). 
Since the ozone in the enclosed pathway is protected from contact with the 
atmosphere, the ozone gas tends to stay in solution in the water during 
the time the ozonated water is being pumped through the enclosed pathway 
102. However, when the ozonated water exits the outlet 66 and comes into 
contact with the atmosphere, any remaining ozone in the ozonated water is 
quickly converted to oxygen, which dissipates into the atmosphere. Since 
no refrigeration or heating devices are shown, it can be seen that no 
artificial chilling or heating of the water is done from the time the 
water enters the tank until it leaves the dialysis machine. After turning 
off the cleaning apparatus 10 and removing the hose 64 from the inlet of 
the dialysis machine 100, any ozone remaining in the dialysis machine 100 
dissipates to the atmosphere, leaving no contaminants in the dialysis 
machine 100. 
The dialysis machine 100 is then ready for use, with no further cleaning or 
rinsing being necessary. However, while it will usually be unnecessary, 
once the flow of ozonated water to the dialysis machine 100 has stopped, 
it can be followed by a flow of clean rinse water to flush out the 
dialysis machine 100. Even if the dialysis machine 100 is rinsed with 
fresh water, a much smaller amount of water will be necessary than the 
amount of water needed to rinse a chemical cleaning solution out of the 
dialysis machine 100, thereby saving the expense of the extra water and 
the increased "down time". 
The operation of the control system of the cleaning apparatus 10 is as 
follows: the on/off switch 72 turns on the electric power supply to the 
electric box 70, and turns on the ozone generator 26 and the first pump 
16. The timer 74 sets the desired amount of cleaning time, and the counter 
76 lets an operator of the dialysis machine 100 know how much time is left 
in the cleaning cycle. The red light 78 lights up whenever the apparatus 
10 is in use, letting any persons desiring to use the cleaning machine 10 
know that they will have to wait before using it. The float 22 in the tank 
20 controls the solenoid valve 24, ensuring that there will be enough 
water inside the tank 20. The pressure switch 32 of the ozone generator 26 
turns on the second pump 18 upon detecting a pressure change which 
indicates that ozone is being drawn into the Venturi tube 28. 
Thus, an apparatus and a method for using ozonated water to clean and 
disinfect a machine or a device has been described. The use of the present 
inventive method, especially when performed by use of the present 
inventive apparatus, provides a quick way of cleaning and disinfecting a 
machine such as a dialysis machine, thus reducing "down time" and allowing 
the machine to be used more often. This quick cleaning is accomplished 
without the use of any toxic chemicals and leaves very little, if any, 
residue on the machine. Moreover, since cleaning chemicals can be quite 
expensive to buy and to dispose of properly, the present inventive method 
provides a much more economical way of cleaning a machine. It should also 
be understood that the present inventive method of cleaning a machine or 
device using ozonated water, as described herein, is fully applicable for 
cleaning other machines and devices having an enclosed liquid pathway with 
an inlet and an outlet. 
It will be obvious to those skilled in the art that modifications may be 
made to the embodiment described above without departing from the scope of 
the present invention.