JP4555399B2 - Medical waste treatment equipment - Google Patents

Description

  The present invention relates to an apparatus for treating medical waste, and more particularly to a continuous treatment type medical waste treatment apparatus using superheated steam.

In order to treat medical waste, it is necessary to sterilize and disinfect it to make it harmless.
In recent years, in the medical field, waste is put into a sealable container to prevent infection, so that the conventional sterilization method using live steam may cause incomplete sterilization.
In addition, incineration has not only the problem of dioxin generation but also a problem of large environmental load.
Therefore, a method using superheated steam heated to a high temperature of 200 ° C. to 400 ° C. has been proposed.

For example, Japanese Unexamined Patent Application Publication No. 2003-251296 discloses a technique for putting medical waste into a heating chamber filled with superheated steam.
However, the technique disclosed in this publication is to melt plastics and the like, and is difficult to handle after that, and there is a problem that harmful gases are generated when carbonized organic substances such as fibers.

  In addition, Japanese Unexamined Patent Application Publication No. 2004-129993 discloses a combustion chamber for generating superheated steam and a technique for effectively using the combustion gas generated here. It is not suitable.

JP 2003-251296 A JP 2004-129993 A

  An object of this invention is to provide the medical waste processing apparatus which can crush and sterilize medical waste continuously, and is excellent in infection prevention property at low cost.

  A medical waste treatment apparatus according to the present invention comprises a medical waste input port, a crushing tank, a sterilization tank, and a discharge port continuously and shielded from the outside air. The sterilization tank has a paddle stirring means and a superheated steam supply means.

In the present invention, when medical waste is introduced from the inlet, it can be crushed in a crushing tank provided at the tip and continuously superheated with steam in the next sterilization tank.
Since it is sterilized by superheated steam after finely pulverizing the medical waste, not only the reliability of sterilization is increased, but also the waste that is put out by sealing medical equipment etc. that may be infectious in a container, The container can be put into the processing apparatus of the present invention from the inlet.
Here, in order to prevent crushed dust and bacteria from leaking to the outside, the waste input port opens the outer door (external door), throws in waste, closes the outer door, and then closes the inner door (inner door). It is preferable to make a double door structure so that it is opened and fed into the crushing tank.
Moreover, it is preferable to employ | adopt the rotary type feeder (it is also called a rotary valve) which can interrupt | block outside air, discharging | emitting the detoxified material processed continuously at a discharge port.
Furthermore, it is ideal to have suction means for maintaining the entire interior of the apparatus in a negative pressure state.

The crushing means from the rotary blade and the fixed blade provided in the crushing tank has high crushing efficiency when the rotary blade is alternately provided with a long blade having a relatively long blade edge and a short blade having a short blade edge.
Here, the arrangement of the rotary blade is characterized in that the length of the blade edge is different between the long blade and the short blade, and there is no particular limitation around the rotation axis, but when the fixed blade is provided on the left and right in the horizontal direction May be a two-way blade with a cutting edge arranged approximately every 180 degrees.
The plurality of rotary blades are preferably arranged such that adjacent rotary blades are shifted by a predetermined angle around the axis.
Medical waste is crushed when the fixed blade and the rotary blade are engaged, but if some of the fixed blades corresponding to the short blade are removed, there is a gap between the rotary blade and the fixed blade. Can do.
For example, the case where fixed blades are provided at two positions on the left and right around the rotation axis will be described.
Of rotary blade fixed blade provided in the direction of the position where the rotation from top to bottom (Fig. 1-3 reference numeral 32a), when the dropping some fixed blade S ₁ corresponding to the short edge 31b (FIG. 3 S portion ₃₎ Te, in this part a gap between the short blade and the fixed blade.
In such a part, it acts to crush the processed material greatly and, when metal medical instruments are mixed, prevent the trouble that this medical instrument bites and stops between the fixed blade and the rotary blade. Can do.

  Furthermore, if a screen casing having a plurality of holes of a predetermined size is installed below the rotary blade, the size of the processed product moving to the sterilization tank can be controlled.

The paddle stirring means provided in the sterilization tank is for the purpose of efficiently bringing the processed product into contact with superheated steam, and a screw-type paddle capable of continuous rotation is preferable for continuous sterilization, for example, Two paddle screws may be arranged in parallel on two axes, and the rotation direction of the two axes may be rotated oppositely from the bottom to the upper side on the opposite side.
If it does in this way, since a processed material will be stirred forward so that it may scoop up from the bottom, it will touch superheated steam uniformly.

Revised in 2004 (2004), which was enacted based on the law on waste treatment and cleaning in Japan, “Regarding infectious waste disposal methods, Hei 16.3.16 According to Chapter 7 of the “Abandoned Development 040316002” guideline, sterilization using a high-pressure steam sterilizer is defined as “acting at a temperature of 121 ° C. or higher for 20 minutes or longer”.
Therefore, the superheated steam in the present invention refers to high-temperature steam at 121 ° C. or higher that satisfies the above-mentioned conditions, and any means for generating superheated steam is usable.
The sterilization time of 20 minutes or more is adjusted by the length and rotational speed of the paddle screw.
In order to use superheated steam efficiently, it is also possible to circulate the inside of the processing apparatus. When a reheat sterilization means and a catalyst processor for removing odors are provided in the middle of the flow path exhausted outside, It is possible to reliably prevent external leakage of bacteria and environmental measures.

In the medical waste treatment apparatus according to the present invention, since the crushing tank and the sterilization tank are continuously provided while blocking the apparatus main body from the outside air, the input medical waste is crushed in the crushing tank, Sterilization can be performed with superheated steam while stirring.
As a result, the processed product is sufficiently exposed to high-temperature heat, sterilization reliability is high, and continuous processing can be performed at low cost.
In addition, the use of superheated steam for sterilization is an environmentally friendly treatment method compared to conventional incineration treatment methods.

The structure of the medical waste processing apparatus which concerns on this invention is shown typically. The internal structure of the crushing tank is shown. The positional relationship of the fixed blades 32a and 32b is shown. The structural example of a screen casing is shown. The internal structure of a sterilization tank is shown. AA line sectional view of a sterilization tank is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Medical waste processing apparatus 20 Input port 21 External door 22 Internal door 30 Crushing tank 31 Rotating blades 32a and 32b Fixed blade 34 Screen casing 40 Sterilization tank 41 and 42 Paddle screw 50 Discharge port 60 Unloading conveyor 70 Superheated steam generator

A structural example of a medical waste treatment apparatus 10 (hereinafter simply referred to as a treatment apparatus) according to the present invention will be described below with reference to the drawings.
FIG. 1 schematically shows the structure of the entire processing apparatus, FIGS. 2 and 3 show examples of the structure of the crushing tank 30, and FIG. 4 shows a screen casing 34 provided at the lower part of the crushing tank.
FIG. 5 shows the internal structure of the sterilization tank 40, and FIG. 6 shows a cross-sectional view taken along line AA.

As shown in FIG. 1, the treatment apparatus 10 according to the present invention has a medical waste input port 20, a crushing tank 30 provided below, and further a sterilization tank 40 arranged in a substantially horizontal direction from the lower side. A discharge port 50 is provided at the tip of the sterilization tank.
The input port 20, the crushing tank 30, the sterilization tank 40, and the discharge port 50 are a continuous processing apparatus designed integrally with the outer wall 11.

Next, it demonstrates according to the flow of a process.
Medical waste is input by opening the external door 21 of the input port 20.
Medical waste that may be infectious is, for example, sealed in a container with a capacity of about 40 L and discarded.
When the external door 21 is opened, the internal door 22 is closed, and the inside of the apparatus is shut off from the outside air.
Next, the outer door 21 is closed, the inner door 22 is opened, and the processed material is put into the crushing tank 30.
The means for putting the temporarily placed processed material into the crushing tank 30 between the outer door 21 and the inner door 22 is not shown in the figure.

In the present embodiment, the crushing tank 30 is provided below the charging port, and the processed material is charged into the crushing tank by free fall.
The crushing tank 30 has a rotary blade 31 that rotates on a rotary shaft 33 with respect to fixed blades 32a and 32b arranged on the left and right in FIG.
As shown in FIG. 2, the rotary blade 31 is provided with a plurality of long long blades 31a having a large outer diameter from the rotating shaft and a plurality of short blades 31b having a short outer diameter and a short outer blade. The positions are shifted by a predetermined angle.
FIG. 3 is a plan view showing the positional relationship between the fixed blades 32a and 32b from above with the covers of FIG. 2 removed.
Rotary blade are arranged alternately and long blades 31a and short blades 31b, the fixed blade 32a, 32b may have a recess _{S 2} that corresponds to the protrusion _{S 1} and Nagaha 31a corresponding to the short edge 31b but the direction of the fixed blade 32a, having a _{S 3} that the missing part of the projection _{S 1,} generally, the number of _{S 1} of the fixed blade 32a is turned half of the fixed blade 32b.
Thus, the processed blade is roughly crushed by the fixed blade 32a whose blade edge is fixed in the downward direction from above, and finely broken by the fixed blade 32b on the opposite side.
The portion of the S ₃ of the fixed blade 32a from a gap is formed between the short blades 31b, the foreign matter that can not be crushed in the rotary blade (for example, a metal having a relatively large medical device) is not contaminated if Even if this occurs, it is possible to prevent a trouble that the rotary blade stops due to falling from the gap and foreign matter biting between the rotary blade and the fixed blade.
Each rotary blade 31 is a two-way blade as schematically shown in FIG.
Since the crushing tank 30 has such a structure, for example, even in the case of a 40 L medical waste container, it can be sufficiently crushed even at a slow rotation speed of about 2 seconds per rotation.
As shown in FIG. 4, the screen casing 34 is provided along the rotation outer diameter of the rotary blade 31 at the lower part of the crushing tank, and the size of the drop holes 34a and 34b provided in the screen casing 34 is set as follows. It is possible to control the size of the processed material put into the sterilization tank 40.

The processed material that has passed through the drop holes 34a and 34b of the screen casing 34 is put into a sterilization tank 40 provided therebelow.
The sterilization tank 40 has an internal structure as shown in FIGS.
6 is a cross-sectional view taken along line AA in FIG.
The bottom of the sterilization tank 40 has a substantially W-shaped cross section as shown in FIG. 6, and paddle screws 41 and 42 are arranged in parallel in two axes (41b and 42b).
The paddle screw 41 and the paddle screw 42 have their rotational directions reversed as W ₁ and W ₂ so as to scoop up the processed material from the bottom upward.
In addition, the blades 41a to 41d and 42a to 42d are arranged so as to face each other so that the processed materials are sequentially fed.

As shown in FIG. 1, superheated steam generated by a superheated steam generator 70 is supplied to the sterilization tank 40.
Various known methods can be employed for the structure of the superheated steam generator 70.
For example, the water in the container is heated to discharge the superheated steam from the container to a high pressure exceeding 1 atm, and high-pressure steam is generated from a water conduit around which an induction heating coil is wound. The method of making it etc. is mentioned as an example.
In addition, the tank shown with the code | symbol 70a in FIG. 1 is an example of a water supply tank, and you may connect water supply piping directly to the superheated steam generator 70. FIG.
The superheated steam is supplied from the processed material inlet of the sterilization tank 40 toward the outlet 50 and is controlled so that the sterilization conditions are 121 ° C. or higher and 20 minutes or longer.
Sterilization becomes insufficient when the temperature of the superheated steam is 120 ° C. or lower.
On the other hand, if the superheated steam is at a high temperature, the sterilization efficiency is increased. However, if the temperature is too high, the plastic or the like is melted, so the temperature is preferably controlled in the range of 125 ° C to 150 ° C.
Moreover, if the temperature drop seems to be large toward the discharge port side, a heater 43 may be provided as necessary.
The superheated steam is supplied into the sterilization tank 40 in the direction indicated by the arrow a ₁ in FIG. 1, and is circulated by the circulation fan 71 from the discharge port 50 side as indicated by the arrow a ₃ .
Further, a part of the superheated steam is supplied also to the crushing tank 30 as shown by an arrow a ₂ , thereby preventing the sterilization tank from being cooled by the injected medical waste and sterilizing the upper part of the apparatus. .
When submitting a medical waste, as shown in suction fan 75 arrow a ₄ by running from near the top of the apparatus of the inlet side, to aspirate the apparatus, is controlled to be in a negative pressure state .
The sucked gas inside the re-heating sterilization heating heater 73 provided in the middle flow channel in the case of exhaust or if circulation gas discharged to the outside air to the outside as shown by an arrow a _5, further filling of the catalyst Then, the odor gas and the like are removed by the catalyst processor 74 and discharged from the exhaust tower 76 to the outside.

A rotary feeder 51 is provided at the discharge port 50, and the processed material rendered harmless while blocking outside air is discharged to the outside, and is conveyed to the storage tanks 62 and 63 by the discharge conveyor 60.
In this embodiment, an example is shown in which a magnetic substance is sorted into the storage tank 63 by using a magnetic separator 61.

  The medical waste treatment apparatus according to the present invention is particularly effective in detoxifying highly infectious waste.

Claims (2)

A medical waste input port, a crushing tank, a sterilization tank, and a discharge port are provided continuously and shielded from the outside air,
The crushing tank has crushing means consisting of a rotary blade and a fixed blade,
The sterilization tank has paddle stirring means and superheated steam supply means,
The crushing chamber and a re-superheating sterilizing means for sterilizing the exhaust from the sterilization vessel, the medical waste disposal which characterized in that it has a catalytic treatment device for removing odor from an exhaust sterilized in the re-superheated sterilizing means apparatus. A medical waste input port, a crushing tank, a sterilization tank, and a discharge port are provided continuously and shielded from the outside air,
The crushing tank has crushing means consisting of a rotary blade and a fixed blade,
The rotary blade has long blades with long blade edges and short blades with short blade edges alternately,
There are a plurality of fixed blades corresponding to the rotary blades, and some of the fixed blades corresponding to the short blades of the rotary blades are missing,
The sterilization tank has a paddle stirring means and a superheated steam supply means.

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