JPS6034392B2 - Steam sterilizer air obstruction removal device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION When steam sterilizing medical instruments and materials such as scalpels, tweezers, forceps, woven belts, surgical gowns, etc., the present invention provides for and an air obstruction removal device for eliminating air within the object to be sterilized so that the sterilization effect is not hindered due to the presence of air.

The evacuation process for removing air obstructions includes a high preliminary vacuum method, a downward movement method, an intermittent evacuation method (positive pressure), an intermittent vacuum method (negative pressure), a vacuum supply method, etc., but the present invention is widely used today. The purpose of this invention is to obtain a device that can effectively remove air from inside a sterilization chamber, and is aimed at the currently practiced vacuum steam supply method.

The present invention makes it possible to efficiently remove air from a decompression chamber by keeping the pressure reduction ratio constant for each wave of repeated pressure reduction in the sterilization chamber by the vacuum pump and pressure increase by the steam supply, and also to prevent the failure of the vacuum pump. If the degree of vacuum in the sterilization room cannot be sufficiently lowered due to performance deterioration or leakage from the sterilization room, vacuum piping, etc., depending on the degree, an alarm will be issued indicating that work is not possible, or a warning will be issued to ensure that work is possible. In the event of a serious problem, we have obtained an air obstruction removal device that can perform air removal processing corresponding to this situation. The present invention will be described below with reference to the drawings.

FIG. 1 schematically shows the basic form of the main parts of a steam sterilizer.

1 is a pressure-resistant sterilization chamber equipped with a tightly fitting lid 2, and the pressure is moderately reduced through a steam supply pipe 4 equipped with a valve 3 (through which sterile steam and sterile air are passed during the sterilization and drying process). It is supplied with steam, and is brought to a low pressure by a removal pipe 7 having a valve 5 and a vacuum pump 6.

In order to eliminate the air in the sterilization chamber 1 sealed with the pipe 2 by vacuum steaming, open the valve 5 with the valve 3 closed, operate the vacuum pump 6, and eliminate the air in the sterilization chamber through the pipe 7. , then close the valve 5 and stop the vacuum pump 6, open the valve 3 and send a small amount of reduced pressure steam into the chamber 1 from the pipe 4, then close the valve 3 again, open the valve 5 and operate the vacuum pump 6. Repeat the operation several times to lower the pressure in chamber 1.

The state of pressure change in the sterilization chamber during the process of eliminating air is as shown in FIG.

Solid line a in FIG. 2 indicates that the vacuum pump 6 is operating normally and the lid 2 is
, indicates a normal state with no leakage to the vacuum system such as tubes 4 and 7, and T
, the pressure inside the sterilization chamber 1 decreases from Po to P by operating the vacuum pump 6 for hours.

A small amount of steam is subsequently supplied from the pipe 4, and the pressure increases to P2 after L hours. When air removal by the vacuum pump is started again, the pressure becomes P3 after T3 hours, the vacuum pump is stopped and steam is supplied from valve 3, and the pressure becomes P4 after T4 hours. The pressure inside becomes P5, and then the vacuum pump 6 is stopped and the sterilization chamber 1 is removed.
A large amount of high-pressure sterilizing steam is blown into the container to begin the sterilization process. However, if the vacuum pump does not operate normally or the vacuum system leaks significantly, and the air removal from the sterilization chamber 1 is extremely poor, the pressure drop within the sterilization chamber 1 over time will be as shown by the broken line b. . In this case, the sterilizer must be stopped and the defective part repaired immediately. When the air removal of the sterilization chamber 1 is poor but better than the case shown by the broken line b, it becomes as shown by the two-dot chain line c.

The present invention is designed to allow emergency sterilization to be carried out in such cases by flowing low-pressure steam. If there is a small amount of air leakage due to poor sealing of the lid 2, leakage of piping, etc., the air exclusion from the sterilization chamber 1 will be as shown by the dashed-dotted line d.

In such a case, the present invention increases the air removal rate by increasing the pressures P2 and P4 during steam supply as shown in the figure, and also uses steam blowing to sufficiently eliminate air obstructions. This was taken into consideration so that the Generally solid line a
The air removal rate K when the pressure decreases due to the vacuum pump and the pressure increases due to the steam supply is repeated is approximately K: Building
The quantity X becomes XQ.

Q' is the air removal rate when steam blowing is used, and cannot be determined by calculation. The present invention
The degree of vacuum in the sterilization chamber is automatically detected, and the above-mentioned curve a,
The present invention provides an air obstruction removal device for a sterilizer that can operate appropriately depending on the conditions b, c, and d.

FIG. 3 schematically shows an embodiment of the present invention, in which a multiple pressure switch 10 communicating with the inside of the sterilization chamber 1 is added to the basic configuration shown in FIG.

As shown in Figure 1, the steam trap, pressure reducing valve,
Ancillary equipment provided to the sterilizer, such as a safety valve and an air filter, are not shown. Next, the operation of this air obstruction removal device will be explained with reference to the block diagram shown in FIG. 4 showing the basic operation.

In FIG. 4, the vacuum pump is designated VP. When the start switch 11 is closed, the vacuum pump 6 is started and the valve 5 is opened. If you continue operating the vacuum pump in this state for 2 minutes,
The pressure inside the sterilization chamber 1 changes from Po to P. Starting and stopping of the vacuum pump, opening and closing of valves, etc. are controlled by a timer and controller (not shown). After two minutes have elapsed, the vacuum pump 6 is stopped and the valve 5 is closed.

The magnitude of the sterilization chamber pressure P, at this time is detected by the multiple pressure switch 101, and this is 0.9 atm (
Absolute value (same below) If not less than the pressure switch 1
0a, it is detected as a failure, and a signal A is sent to the buzzer 8, which is an alarm device, to issue an alarm. 0 even below 0.9 atmospheres
．． If the pressure is not lower than 4 atm, a signal B indicating that the performance of the vacuum pump 6 has deteriorated is issued from the pressure switch 10b, which opens both valves 3 and 5, and the reduced pressure steam sent from the pipe 4 is It blows through the sterilization chamber 1 and exhausts the air inside the object to be sterilized together with steam.

This blow steam supply time may be about 2 minutes, and it is controlled by a timer and a controller (not shown), and after 2 minutes, the valve 5 is closed, and the steam sterilization is carried out using a large amount of steam sent from the pipe 4.
Move on to the drying process. When the pressure P in the sterilization chamber 1 is below 0.4 atm but not below 0.2 atm, the timer is started by the signal C output from the pressure switch 10c, and the pressure P after the sand in step 6 is changed to the pressure switch 10e. Detected by

This allows us to know whether the vacuum level is not rising due to a leak in the vacuum system of the sterilizer, or whether it is due to a decline in the performance of the vacuum pump itself. (Vacuum pump performance includes temperature,
There is a fluctuation of 0.1 to 0.2 atm depending on the water temperature (in the case of a water seal type), moisture absorption of the object to be sterilized, capacity, etc. ) Close the valve 5 and leave it as it is, for example, the pressure in the sterilization room will change from 0.2 atm to 0.25 atm.
If the air pressure rises, there is a leak and there is a danger that contaminated air from outside will leak into the sterilization chamber, so a signal 〇 is sent from the pressure switch 10e to the buzzer 8. be warned. If the pressure rise is small and does not appear to be a leak in the vacuum system, turn pressure switch 1 on.
The valve 3 is opened by the signal 0' of 0e, and steam at, for example, 1.6 atmospheres is supplied from the pipe 4 for a short time, blows through the sterilization chamber 1, and is discharged through the open valve 5. , perform air exclusion.

When the pressure in the sterilization chamber is lower than 0.2 atm but not below 0.1 atm, the pressure switch 10d outputs a signal D, opens the valve 3, and removes air by a flow of low-pressure steam at 1.2 atm. .

If the pressure inside the sterilization chamber 1 is under normal conditions of 0.1 atm or less, there is no need to blow the steam, but in the embodiment shown in FIG. Steam is blown at a pressure of 0.8 atm.

After that, the same goes for the cases where the steam is blown at 0.2 atm or more and 0.1 atm or more, but a signal is sent to the counter 9 and the number of air removal processes is counted.
While the air removal operation is not repeated, for example, 3 times, the counter 9
Valve 3 is closed by signal E from , the above operation from the start is repeated, and once the 3 lines have been returned, the next sterilization,
Move on to the drying process. As described above, the air obstruction removal device for a steam sterilizer of the present invention uses a pressure switch to detect the pressure inside the sterilization chamber, which has been reduced by a vacuum pump, and removes air by changing the degree of pressure increase due to steam supply depending on the level of the pressure. It automatically operates to maintain a good rate, to use a blow of steam at a moderately reduced pressure if the air removal is not good, and to issue an alarm if the air removal is extremely poor,
This device is effective as a device that always performs good air obstruction removal and allows subsequent sterilization and drying steps to be performed well.

This air obstruction removal device can be applied not only to steam sterilizers but also to gas sterilizers, and can be used safely by providing a device that renders the removed gas harmless and disposes of it. be.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram showing the basic configuration of a conventional steam sterilizer for removing air obstructions, Fig. 2 is a diagram showing pressure changes in the sterilization chamber, and Fig. 3 is a diagram showing the air obstruction removal device of the present invention. A schematic diagram of a steam sterilizer, FIG. 4 is a diagram showing the operation of this device. 1: Sterilization chamber, 2: Lid, 3, 5: Valve, 4, 7: Pipe, 6: Vacuum pump, 8: Buzzer, 9: Counter, 10: Multiple pressure switch, 10a to 10e: Pressure switch, 11: Start switch. Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] 1. In a steam sterilizer in which a steam supply pipe 4 equipped with a valve 3 and a discharge pipe 7 equipped with a valve 5 and a vacuum pump 6 are connected to a sealable sterilization chamber 1, the operating pressures differ. A plurality of pressure switches are connected to the inside of the sterilization chamber 1, and the pressure switches shall issue a signal depending on the degree of pressure drop in the sterilization chamber, and the corresponding pressure switch shall be set to an alarm in the event that operation is not possible. If connected and operational, the higher the pressure inside the sterilization chamber, the higher the pressure is blown into the sterilization chamber, the higher the decompression ratio inside the sterilization chamber, the air is repeatedly removed, and finally the reduced pressure steam is supplied as it blows through the sterilization chamber. An air obstruction removal device for a steam sterilizer, characterized in that it is connected to a controller.