JP4344157B2 - Method and apparatus for processing used animal flooring material - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a processing method and a processing apparatus for flooring material for drying, deodorizing and sterilizing the flooring material used as flooring for laboratory animals, livestock and the like.
[0002]
[Prior art]
In the breeding of laboratory animals and livestock, chips such as wood and paper are used as a floor covering material to absorb animal urine and excrement. When the animal flooring material absorbs animal urine and excreta, it produces a bad odor due to ammonia, the water and oil absorbability deteriorates, and spoilage bacteria also occur. Therefore, it is regularly exchanged so as not to deteriorate the animal breeding environment.
[0003]
[Problems to be solved by the invention]
Here, until now, used flooring materials have been disposed of as medical waste. If the used flooring material can be dried, deodorized and sterilized for reuse, it is preferable because it saves resources.
[0004]
An object of the present invention is to propose a processing method and a processing apparatus that can recycle a used animal flooring material by drying, deodorizing and sterilizing it.
[0005]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the floor covering material processing method of the present invention is a method for exposing a used animal floor covering material to water vapor having a pressure lower than a saturated vapor pressure, and thereby removing foreign matter contained in the floor covering material. And the floor covering material is dried, deodorized and sterilized . That is, as described below, it is characterized by selectively dissolving and extracting / separating foreign substances with dry steam and decomposing bacterial microorganisms.
[0006]
By treating the used animal flooring material with water vapor having a pressure lower than the saturated vapor pressure, the flooring material can be efficiently dried. In addition, when the flooring material is heated with water vapor having a pressure lower than the saturated vapor pressure, the perishable substance is decomposed into a hardly perishable substance, and sterilization such as spoilage bacteria is performed. Furthermore, since the ammonia causing the bad odor can be separated by thermal decomposition, the flooring material is also deodorized. Furthermore, by controlling the severe decomposition / reduction reaction due to thermal decomposition by adjusting the temperature and pressure of water vapor with a pressure lower than the saturated vapor pressure, the absorbability of animal excrement in the treated flooring material Can be recovered.
[0007]
Moreover, in the method of this invention, the temperature of the water vapor | steam of the pressure lower than the said saturated vapor pressure is made into the range from 100 degreeC to 200 degreeC . Further, the pressure of the water vapor having a pressure lower than the saturated vapor pressure is set in a range from 0.1 MPa to the saturated vapor pressure .
[0008]
Furthermore, in the method of the present invention, the vapor density of water vapor having a pressure lower than the saturated vapor pressure is controlled using an inert gas . In this case, nitrogen gas can be used as the inert gas.
[0010]
In addition, it is desirable that the gas generated by the thermal decomposition is cooled and separated into a gas phase gas and a liquid phase gas, and the separated gas phase gas and liquid phase gas are separately recovered .
[0011]
Next, the present invention is a flooring material processing apparatus, characterized in that the used animal flooring material is regenerated by the above processing method. That is, the processing apparatus for flooring material of the present invention includes: putting a used laboratory animal flooring material, exposing the used animal flooring material to water vapor having a pressure lower than a saturated vapor pressure, A heat treatment chamber for decomposing, deodorizing and sterilizing the used animal flooring material, and generating water vapor at a pressure lower than the saturated vapor pressure; A steam generation chamber for supplying the processing chamber; a separation chamber for separating the extraction gas discharged from the processing chamber into a liquid phase gas and a gas phase gas; and a liquid phase gas and a gas phase gas from the separation chamber separately. And a collection chamber for collection.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
An example of a flooring material processing method and processing apparatus to which the present invention is applied will be described below with reference to the drawings.
[0013]
(Processing equipment for flooring materials)
FIG. 1 is a schematic configuration diagram showing the floor covering material processing apparatus of this example. As shown in this figure, the processing apparatus 1 of this example includes a processing chamber 3 in which a wooden chip 2 that is a used floor covering material for laboratory animals is placed, and steam generation that generates water vapor having a pressure lower than the saturated vapor pressure. Chamber 4. By supplying steam having a pressure lower than the saturated vapor pressure from the steam generation chamber 4 into the processing chamber 3, the wooden chip 2 in the processing chamber 3 is heated and thermally decomposed to dry, deodorize and sterilize the wooden chip 2. And the wood chip 2 is regenerated.
[0014]
Further, the processing apparatus 1 includes a separation chamber 5 that separates an extraction gas generated by pyrolyzing the wood chip 2 and discharged from the processing chamber 3 into a liquid phase gas and a gas phase gas, and a liquid from the separation chamber 5. And a recovery chamber 6 for separately recovering the phase gas and the gas phase gas. Thereby, the contaminants of the extraction gas can be separated and recovered.
[0015]
The processing chamber 3 has a cylindrical shape extending vertically, and the inside can be heated by a heater 32 attached to the outer wall 31. Inside the processing chamber 3, a plurality of storage shelves 33 for storing the wood chips 2 for each predetermined amount are stacked from the bottom wall 34. Pipes 41 a, 41 b, 41 c from the steam generation chamber 4 are connected to the bottom wall 34. A thermocouple 36 for measuring the internal temperature and a pipe 51 communicating with the separation chamber 5 are attached to the upper wall 35 of the processing chamber 3.
[0016]
The steam generation chamber 4 has a cylindrical shape that extends vertically like the processing chamber 3, and can heat steam with a heater 43 attached to the outer wall 42 to generate water vapor having a pressure lower than the saturated vapor pressure. It has become. The steam generation chamber 4 is filled with a large number of beads 4a each having a diameter of about 2 mm made of a metal (copper, brass, etc.) having good heat conductivity, and a heater wire 4b for heating the beads 4a is formed in a coil shape. Has been routed. By heating a large number of beads 4a, the steam generation chamber 4 can also be heated from the inside. A pipe 41 a communicating with the processing chamber 3 is connected to the upper wall 44 of the steam generation chamber 4, and steam having a pressure lower than the saturated vapor pressure is supplied to the processing chamber 3 through the pipe 41 a.
[0017]
Further, a thermocouple 46 for measuring the internal temperature is attached to the upper wall 44, and a pipe 41 b communicating with the processing chamber 3 is also connected. The pipe 41b has a tip 41d extending to the vicinity of the bottom wall 47 of the steam generation chamber 4, and is connected to a pipe 45b of the organic water mixed solvent supply pump 45 through a switching valve 45a. The organic water mixed solvent supply pump 45 can supply the organic water mixed solvent to one of the processing chamber 3 and the steam generation chamber 4 by switching and controlling the switching valve 45a.
[0018]
The bottom wall 47 of the steam generation chamber 4 is connected to a discharge side pipe 48 a of a water supply pump 48 and a pipe 49 a from an inert gas supply source 49. The pipe 48a on the discharge side of the water supply pump 48 is connected to the pipe 41c communicating with the processing chamber 3 via the switching valve 48b, so that water can be supplied to the processing chamber 3 as well. The inert gas supply source 49 is for supplying an inert gas, for example, nitrogen gas, to the steam generation chamber 4.
[0019]
Next, the separation chamber 5 includes a condenser tube 52 that cools the extraction gas discharged from the pipe 51 connected to the processing chamber 3 and separates it into a gas phase gas and a liquid phase gas. The condensing pipe 52 is connected to the recovery chamber 6.
[0020]
The recovery chamber 6 includes a gas phase gas recovery chamber 61 and a liquid phase gas recovery chamber 62, which are joined at a branching portion 53 of the condensing pipe 52 via pipes 61a and 62a, respectively. Ammonia contained in the gas phase gas recovered in the gas phase gas recovery chamber 61 is absorbed by the sulfuric acid solution filled in the gas phase gas recovery chamber 61.
[0021]
(Processing procedure for wood chips)
A processing procedure of the wood chip 2 using the processing apparatus 1 configured as described above will be described.
[0022]
First, a predetermined amount of the used wood chips 2 is stored in a plurality of storage shelves 33 in the processing chamber 3. Next, water is supplied to the steam generation chamber 4 from the water supply pump 48, and the steam generation chamber 4 is heated by the heater 43 and the internal heater wire 4b to generate water vapor having a pressure lower than the saturated vapor pressure. While supplying water vapor having a pressure lower than the saturated vapor pressure to the processing chamber 3, maintaining the inside of the processing chamber 3 at a predetermined temperature and a predetermined pressure, and adjusting a supply flow rate of water vapor having a pressure lower than the saturated vapor pressure, The wood chip 2 is heated and thermally decomposed. Thereby, the wood chip 2 is dried, deodorized, and sterilized.
[0023]
The temperature of the water vapor having a pressure lower than the saturated vapor pressure is set in a range from 100 ° C. to 200 ° C., and the pressure is set in a range from 0.1 MPa to the saturated vapor pressure. By adjusting the temperature and pressure of water vapor having a pressure lower than the saturated vapor pressure so as to be in this range, the severe decomposition / reduction reaction in the thermal decomposition of the wood chip 2 can be mitigated.
[0024]
The vapor density of water vapor having a pressure lower than the saturated vapor pressure can be adjusted as follows. That is, an inert gas is supplied to the steam generation chamber 4 from an inert gas supply source 49, a mixed gas with water vapor having a pressure lower than the saturated vapor pressure is supplied to the processing chamber 3, and the supply amount of the inert gas is increased. The process chamber 3 is adjusted to a desired vapor density state. Further, the vapor density in the processing chamber 3 may be adjusted by supplying the inert gas directly from the inert gas supply source 49 to the processing chamber 3.
[0025]
In addition, the selective reaction in the decomposition / reduction reaction with water vapor having a pressure lower than the saturated vapor pressure can be controlled as follows. That is, selective reaction control is performed by adjusting the type and amount of the organic substance in the organic water mixed solvent supplied to the processing chamber 3. If the organic water mixed solvent is supplied to the processing chamber 3 from the organic water mixed solvent supply pump 45 to the steam generation chamber 4 and mixed with water vapor and / or an inert gas having a pressure lower than the saturated vapor pressure, Good. Further, the organic water mixed solvent may be directly supplied to the processing chamber 3 from the organic water mixed solvent supply pump 45.
[0026]
In the processing chamber 3, the extraction gas generated by pyrolyzing the wood chip 2 is separated into a gas phase gas and a liquid phase gas through the condensation pipe 52 of the separation chamber 5. These gas phase gas and liquid phase gas are recovered in the gas phase gas recovery chamber 61 and the liquid phase gas recovery unit 62, respectively.
[0027]
(Wood chips after processing)
Here, the following experiment was performed using the processing apparatus 1 of this example. For 6 grams of wood chips 2 soaked in 8.5 grams of 10% ammonia water, the temperature ranges from 120 ° C. to 200 ° C. and the pressure is 0.2 MPa as water vapor having a pressure lower than the saturated vapor pressure. To 0.62 MPa was supplied for 80 minutes. As a result, the following points were confirmed.
[0028]
First, it was confirmed that the color of the wood chip 2 after the treatment became darker as the temperature and pressure of water vapor having a pressure lower than the saturated vapor pressure increased.
[0029]
Next, the dryness of the treated wood chip 2 was examined. Therefore, as shown in FIG. 2, the weight reduction rate of the wood chip when using water whose pressure is lower than the saturated vapor pressure and whose pressure is 0.36 MPa and whose temperature is changed from 120 ° C. to 200 ° C. Was measured. As a result, it was confirmed that when the pressure of the water vapor having a pressure lower than the saturated vapor pressure is constant, the wood chip 2 is better dried as the temperature is higher.
[0030]
Further, the weight reduction rate of the wood chip 2 was measured when the temperature of water vapor having a pressure lower than the saturated vapor pressure was made constant. When water vapor having a pressure lower than the saturated vapor pressure and having a temperature of 170 ° C. and a pressure of 0.2 MPa was used, the weight reduction rate was 5.1%. On the other hand, when the pressure was 0.36 MPa, the weight reduction rate was 3.7%. Therefore, it was confirmed that the lower the pressure, the better the dryness of the wood chip 2.
[0031]
Next, the deodorization condition of the treated wood chip 2 was examined. As shown in FIG. 3, the vapor pressure of the vapor phase gas recovery chamber 62 when the water vapor pressure is lower than the saturated vapor pressure is 0.36 MPa and the temperature is changed to 120 ° C., 140 ° C., 170 ° C., 200 ° C. The recovery rate of ammonia was measured. As a result, the ammonia recovery rate was 54% or more. When steam having a temperature lower than the saturated vapor pressure at 200 ° C. was used, the ammonia recovery rate was 97%. Therefore, it was confirmed that the higher the temperature, the higher the degree of deodorization.
[0032]
Moreover, the temperature of the water vapor having a pressure lower than the saturated vapor pressure was set to 170 ° C., and the deodorization condition of the wood chip 2 when the pressure was changed was examined. The ammonia recovery rate was 53.6% at a pressure of 0.2 MPa, and 54.8% at a pressure of 0.36 MPa.
[0033]
Next, among the absorbability of ammonia and oil of the wood chip 2, the absorbability with respect to ammonia was examined. 2 g of dried, deodorized and sterilized wood chips were placed in a beaker containing 6 g of a 10% ammonia solution, placed in a sealed dry container, left for 15 hours and then taken out, and the ammonia absorption rate was measured. As shown in FIG. 4, when the water vapor having a pressure lower than the saturated vapor pressure is 0.36 MPa and the temperatures are 120 ° C., 140 ° C., 170 ° C. and 200 ° C., the pressure is 0.21 MPa and the temperature is 170 ° C. In this case, the pressure was 0.62 MPa and the temperature was 170 ° C. As a result, the ammonia absorption rate of the treated wood chip 2 was equal to or higher than the ammonia absorption rate of the unused wooden chip, and had an ammonia absorption rate equal to or higher than that of the unused product.
[0034]
Next, the absorbability with respect to the oil of the processed wood chip 2 was examined. For this purpose, a glass tube filled with the treated wood chips 2 was immersed in oil, and the absorption height of the oil was measured. When the pressure of water vapor lower than the saturated vapor pressure is 0.36 MPa and the temperature is 120 ° C., 140 ° C., 170 ° C. and 200 ° C., the pressure is 0.21 MPa and the temperature is 170 ° C., the pressure is 0 The oil absorption height after the treatment was measured when the temperature was set to 170 ° C. at 0.62 MPa. The result is shown in FIG. It was confirmed that the oil absorption height was higher than that of the unused product, and the oil absorption was superior to that of the unused product.
[0035]
Here, it was observed that a hole portion observed in the unused wood chip was connected to the surface texture of the treated wood chip 2 to form a wide open recess. It is considered that the oil absorbability is improved by such a change in the surface texture.
[0036]
【The invention's effect】
As described above, in the floor covering material processing method and processing apparatus of the present invention, water vapor having a pressure lower than the saturated vapor pressure is used for drying, deodorizing and sterilizing the used floor covering material.
[0037]
It was confirmed that by using water vapor with a pressure lower than the saturated vapor pressure, the flooring material can be efficiently dried, and the septic substances contained therein can be decomposed into refractory substances and can sterilize spoilage bacteria. . It was also confirmed that ammonia causing the bad odor was separated by thermal decomposition, and the flooring material could be deodorized. Furthermore, it was confirmed that the absorbability of animal excreta was also improved.
[0038]
Therefore, according to this invention, the method and apparatus which can reproduce | regenerate the animal flooring material are realizable.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing an embodiment of an apparatus for treating flooring material according to the present invention.
FIG. 2 is a graph showing a weight reduction rate of a wood chip due to a difference in temperature of water vapor having a pressure lower than a saturated vapor pressure in the method of the present invention.
FIG. 3 is a graph showing the ammonia recovery rate from the flooring material according to the difference in the temperature of water vapor having a pressure lower than the saturated vapor pressure in the method of the present invention.
FIG. 4 is a table showing the ammonia absorption rate of the flooring material after treatment according to the difference in temperature and pressure of water vapor having a pressure lower than the saturated vapor pressure in the method of the present invention.
FIG. 5 is a graph showing the oil absorption height of the flooring material after treatment according to the difference in temperature and pressure of water vapor having a pressure lower than the saturated vapor pressure in the method of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Floor covering processing apparatus 2 Floor covering material 3 Processing chamber 4 Steam generation chamber 5 Separation chamber 6 Recovery chamber 31 Outer wall 32 Heater 33 Storage chamber 34 Bottom wall 35 Upper wall 36 Thermocouple 41a, 41b, 41c Piping 42 Outer wall 43 Heater 44 Above Wall 46 Thermocouple 47 Bottom wall 45 Organic water mixed solvent supply pump 45a Switching valve 45b Pipe 48 Water supply pump 48b Switching valve 49 Inert gas supply source 51 Pipe 52 Condensation pipe 53 Branch portion 61 Gas phase gas recovery chamber 62 Liquid Phase gas recovery room

Claims (4)

The used animal flooring material is exposed to water vapor having a pressure lower than the saturated vapor pressure to thermally decompose foreign matter contained in the flooring material, and the flooring material is dried, deodorized and sterilized.
The temperature of the water vapor at a pressure lower than the saturated vapor pressure is within a range from 100 ° C. to 200 ° C .;
The pressure of water vapor having a pressure lower than the saturated vapor pressure is within a range from 0.1 MPa to saturated vapor pressure,
A method for treating a flooring material, wherein the vapor density of water vapor having a pressure lower than the saturated vapor pressure is controlled using an inert gas. In claim 1,
The method for treating a flooring material, wherein the inert gas is nitrogen gas. In claim 1 or 2,
A method for treating a flooring material, wherein the gas generated by the thermal decomposition is cooled and separated into a gas phase gas and a liquid phase gas, and the separated gas phase gas and liquid phase gas are separately collected. A processing apparatus for flooring material for reclaiming used animal flooring material by the processing method according to any one of claims 1 to 3,
Put the used animal flooring material, expose the used animal flooring material to water vapor with a pressure lower than the saturated vapor pressure, and thermally decompose foreign substances contained in the used animal flooring material. And a processing chamber for drying, deodorizing and sterilizing the used animal flooring material,
A steam generation chamber that generates water vapor having a pressure lower than a saturated vapor pressure and supplies the water vapor to the processing chamber;
An inert gas supply source for supplying an inert gas to the steam generation chamber;
A separation chamber for separating the extraction gas discharged from the processing chamber into a liquid phase gas and a gas phase gas;
An apparatus for processing a flooring material, comprising: a recovery chamber for separately recovering a liquid phase gas and a gas phase gas from the separation chamber.

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