JP7276086B2 - Device for promoting solubilization of organic matter - Google Patents

Description

TECHNICAL FIELD The present invention relates to an organic substance solubilization promoting device for promoting the solubilization of organic substances such as microorganisms contained in sludge or the like.

As a technique for destroying the cell walls of microorganisms in sludge to promote solubilization, for example, Patent Document 1 discloses heating the sludge to be treated to 60 to 95 ° C. and further generating cavitation in the sludge. ing.
Further, Patent Document 2 discloses that microbubbles made of a non-condensable gas such as CO ₂ are brought into contact with a heated organic residue, and the crushing of the microbubbles accelerates the solubilization of the organic residue.

In addition, although it is not a device for promoting the solubilization of organic matter, Patent Document 3 discloses that a venturi tube nozzle is provided with a large number of steam holes at a plurality of positions in the radial direction and the downstream direction, and LNG is circulated through the venturi tube nozzle. Also, a technique is disclosed for efficiently reliquefying by injecting the evaporative gas of LNG from the steam vent and bringing the evaporative gas into contact with the LNG.

JP-A-2004-195421 JP 2017-121603 A JP 2016-183781 A

As disclosed in Patent Document 1, the liquid substance is heated and cavitation is generated, and in addition, as disclosed in Patent Document 2, a process of generating microbubbles by injecting non-condensable gas is performed. By doing so, a greater solubilizing effect can be expected than when each treatment is performed alone or when any two treatments are performed.
A venturi tube type fluid nozzle that expands after contracting a flow path can be applied as a device that simultaneously incorporates all of the processes of heating, generating cavitation, and generating microbubbles by injecting non-condensable gas as described above.

However, when cavitation is generated in the liquid substance to be treated and, in addition, microbubble treatment is performed by injecting a non-condensable gas, the liquid substance flows as a gas-liquid two-layer flow. When a venturi tube type fluid nozzle is applied to a flow field in which such a gas-liquid two-phase flow occurs, the pressure loss becomes larger than in the case of a liquid single-phase flow with the same flow velocity, and the flow through the venturi tube type fluid nozzle A problem arises in that the energy consumption of the device (power-driven pump, steam-driven injector, etc.) increases.

In this regard, it is conceivable to generate microbubbles with a condensable gas instead of a noncondensable gas. The aforementioned Patent Document 3 can be cited as a device in which a condensable gas is blown into a venturi tube type fluid nozzle. The venturi tube-type fluid nozzle of Patent Document 3 is a device that sucks condensable evaporative gas from a large number of dispersed steam holes and mixes it with a low-temperature liquid that flows through the venturi tube-type fluid nozzle.

However, since the venturi tube type fluid nozzle of Patent Document 3 has a large number of steam holes, the flow velocity of the evaporative gas sucked from each steam hole is small, and the jetted evaporative gas contacts the low-temperature fluid and immediately condenses.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and provides an apparatus for promoting the solubilization of organic matter that can efficiently promote the solubilization of organic matter contained in sludge or the like without increasing energy consumption. It is an object.

(1) A device for promoting solubilization of organic matter according to the present invention promotes solubilization of organic matter contained in a liquid substance,
a heating device that heats the liquid substance; a fluid nozzle that causes the liquid substance heated by the heating device to flow to generate cavitation in the liquid substance; and a steam injection nozzle that injects at the above speed.

(2) In the nozzle described in (1) above, the fluid nozzle is a venturi tube nozzle having a throat, and the steam injection nozzle is provided in and/or in the vicinity of the throat. It is characterized by

(3) In the above (1), the fluid nozzle is a venturi tube nozzle having a throat, and the steam injection nozzle is the throat and/or defined by the following formula (1): It is characterized in that it is provided at the position of the cross-sectional area A of the flow path.
Ath≦A≦Q×(0.5×ρ÷ΔP) ^0.5 (1)
However, Ath: cross-sectional area of the throat A: cross-sectional area of the flow path in the cavitation region Q: flow rate of the liquid substance ρ: density of the liquid substance ΔP: the ratio between the outlet pressure of the venturi tube nozzle and the saturated vapor pressure of the liquid substance Pressure difference

(4) Further, in the above (1) to (3), the steam injection nozzle is a Laval type nozzle.

In the present invention, a heating device for heating a liquid substance, a fluid nozzle for generating cavitation in the liquid substance by circulating the liquid substance heated by the heating device, and a cavitation generation region in the fluid nozzle By installing a steam injection nozzle that injects steam at a speed higher than the speed of sound, microbubbles generated by cavitation and steam promote the solubilization of organic matter in the liquid material. In addition, since the remaining microbubbles disappear by condensation, the liquid material becomes almost a liquid monolayer flow, and the pressure loss does not increase. can efficiently promote

BRIEF DESCRIPTION OF THE DRAWINGS It is explanatory drawing of the solubilization acceleration|stimulation apparatus of the organic matter which concerns on embodiment of this invention. FIG. 2 is an explanatory diagram of a mounting mode of a steam injection nozzle in the solubilization promoting device shown in FIG. 1; FIG. 3 is an explanatory diagram of another aspect of the steam injection nozzle in the solubilization promoting device shown in FIG. 1; FIG. 5 is an explanatory diagram of another mounting mode of the steam injection nozzle in the solubilization promoting device of the present embodiment; FIG. 4 is an explanatory diagram of another aspect of the fluid nozzle in the solubilization promoting device of the present embodiment;

An organic substance solubilization promoting device 1 according to one embodiment of the present invention is a device for promoting the solubilization of organic substances contained in a liquid substance. A heating device 3, a fluid nozzle 5 for circulating a liquid substance heated by the heating device 3 to generate cavitation in the liquid substance, and steam injected into a cavitation generation region 7 of the fluid nozzle 5 at a speed equal to or higher than the speed of sound. It is characterized by having a steam injection nozzle 9 that
Each configuration will be described in detail below.

<Organic matter>
Organic matter is, for example, microorganisms and other organic matter contained in liquid substances such as excess sludge and thickened sludge generated in wastewater treatment facilities.

<Warming device>
The heating device 3 is a device for heating the liquid substance to, for example, 60 to 95° C., for example, heating by heat exchange with hot water.

<Fluid nozzle>
The fluid nozzle 5 is a device that circulates a liquid substance containing an organic substance to generate cavitation. Cavitation occurs when the static pressure of a fluid is lower than the saturated vapor pressure of the fluid. Also, when the fluid is water, the higher the liquid temperature, the higher the saturated vapor pressure. In this embodiment, a venturi type nozzle as shown in FIG. 1 is used as the fluid nozzle 5 that can generate cavitation by utilizing the pressure drop that converts the static pressure into the dynamic pressure by narrowing the aperture.

According to the principle of cavitation generation in a venturi nozzle, if the liquid temperature is low, the saturated vapor pressure is low, so the flow velocity must be increased in order to generate cavitation. However, as the flow velocity increases, the pressure loss also increases, so the required nozzle inflow pressure also increases.
Therefore, in the present embodiment, as shown in FIG. 1, the liquid substance is heated by the heating device 3 and supplied to the fluid nozzle 5, thereby increasing the flow velocity without increasing the nozzle inflow pressure. Cavitation can be easily generated without increasing the size.

<Steam injection nozzle>
The steam injection nozzle 9 is a nozzle for injecting steam into the cavitation generation region 7 of the fluid nozzle 5 at a speed equal to or higher than the speed of sound. A shaped nozzle is used.
In addition, as shown in FIG. 2, the steam injection nozzle 9 is installed in the cavitation generation area 7 so as to inject in the tangential direction of the cross section of the flow path of the area.
When the fluid nozzle 5 is a venturi type nozzle, the cavitation generation region 7 in the fluid nozzle 5 is the throat portion 11 and its vicinity. is the range represented by formula (1), and more preferably the range represented by formula (2) in which cavitation occurs strongly.
Ath≦A≦Q×(0.5×ρ÷ΔP) ^0.5 (1)
Ath≦A≦Q×(0.4×ρ÷ΔP) ^0.5 (2)
where, Ath is the cross-sectional area of the throat, A is the cross-sectional area of the cavitation area, Q is the flow rate of the liquid material, ρ is the density of the liquid material, and ΔP is the outlet pressure of the venturi tube nozzle and the liquid material. is the pressure difference from the saturated vapor pressure.

As the steam, as shown in FIG. 1, for example, steam generated in a boiler 13 is used. Microbubbles are generated by injecting steam from the steam injection nozzle 9 into the cavitation generation region 7 at a speed equal to or higher than the speed of sound. This principle will be explained below.
Steam may be any gas other than water vapor as long as it is a gas that is wholly condensed or wholly dissolved in the processing fluid.

In general, when gas is ejected into a liquid, bubbles are generated and split by the action of fluid force between the liquid and the gas. As the flow velocity difference between the liquid and the gas increases, the fluid force acting between the liquid and the gas increases, and the bubbles are easily split and the diameter is reduced.

On the other hand, when steam generated by a boiler or the like is ejected into water at normal temperature and normal pressure, the steam tends to condense into water, making it difficult to generate and split sufficient bubbles.
However, for example, when a processing fluid heated to 60 to 95° C. is passed through the fluid nozzle 5 to generate cavitation, the region is in a boiling state at a pressure lower than the saturated vapor pressure of the processing fluid. Blowing steam over an area does not condense the steam.

In addition, the pressure in the cavitation generation region 7 has a large pressure difference with the steam generated by the boiler 13 or the like. Steam can be blown into it at high speed.
The vapor blown into the cavitation generation region 7 does not condense in the processing fluid, and since it is at high speed, it becomes air bubbles by the action of the fluid force between the processing fluid and splits to form microbubbles.

The microbubbles generated from the blown steam are crushed in the process of expanding the flow path of the venturi tube nozzle and recovering the pressure, and exhibit the action of solubilizing organic matter. For this reason, the frequency of bubble collapse is increased compared to the case where only liquid cavitation is performed without injecting steam, so that the solubilization of organic matter is promoted.

In addition, since steam is condensable with respect to the processing fluid, microbubbles remaining without being crushed disappear by condensation. As a result, the liquid substance becomes almost a monolayer flow, and pressure loss does not increase, so energy consumption does not increase.
Some of the gases (mainly air) contained in the processing fluid and the injected steam remain as bubbles, but the amount of the bubbles is small, and eventually they dissolve and disappear.

In the apparatus 1 for promoting solubilization of organic matter configured as described above, liquid substances such as excess sludge generated in wastewater treatment facilities, for example, are heated to 60 to 95° C. by the heating device 3, for example, It is supplied to the fluid nozzle 5 at a flow rate of 5 to 30 m/s. The supplied liquid substance has a saturated vapor pressure in the throat 11 . On the other hand, steam is injected from the steam injection nozzle 9 at a pressure of about twice or more the saturated steam pressure of the throat 11 .
The injected vapor becomes microbubbles, and the cavitation generated by the fluid nozzle 5 and the crushing of the microbubbles solubilize the organic substances.
However, microbubbles are generated by condensable vapor, and the bubbles are crushed in the region of the expanded flow path of the venturi nozzle, and the processing fluid becomes a liquid single-phase flow without causing a large pressure loss. , downstream.

As described above, in the present invention, by blowing steam into the cavitation generation region 7 of the fluid nozzle 5 at high speed, microbubbles are additionally generated and crushed, and the steam condenses in the trailing stream to form a liquid single-phase flow. Therefore, promotion of solubilization can be realized with relatively low energy consumption.

The shape of the steam injection nozzle 9 is not limited to the tapered type shown in FIG. 1, but may be a straight type as shown in FIG. Applicable. A Laval type nozzle is more preferable because it facilitates the jetting of steam at supersonic speed.
Also, the direction in which steam is injected from the steam injection nozzle 9 is not limited to the tangential direction of the cross section of the fluid nozzle shown in FIG. 2, and may be the radial direction of the cross section of the fluid nozzle as shown in FIG.
Further, the number of steam injection nozzles 9 may be singular or plural (preferably about 1 to 4) under the condition that the steam can be jetted at the speed of sound or higher. When a plurality of steam injection nozzles 9 are provided, they may be provided on the same cross section of the fluid nozzle 5 or may be provided on different cross sections shifted in the direction of the flow path.

Further, when a venturi type nozzle is used as the fluid nozzle 5, the inner surface shape of the region where the flow path expands on the downstream side of the throat portion 11 in the venturi type nozzle is a flat shape as shown in FIG. However, as shown in FIG. 5, the flow path may have a shape that expands in a stepwise manner.
When the diameter of the flow path expands stepwise, the vapor splits at the stepped portion to form finer microbubbles, and the number of bubbles increases, so that the effect of promoting solubilization by collapsing the bubbles can be enhanced.

REFERENCE SIGNS LIST 1 solubilization promotion device 3 heating device 5 fluid nozzle 7 cavitation generation region 9 steam injection nozzle 11 throat 13 boiler

Claims (3)

An organic substance solubilization promoting device for promoting the solubilization of organic substances contained in a liquid substance,
a heating device for heating the liquid substance; a fluid nozzle having a throat portion for causing the liquid substance heated by the heating device to flow to generate cavitation in the liquid substance; and a cavitation generation region in the fluid nozzle. and a steam injection nozzle for injecting steam at a speed equal to or higher than the speed of sound, provided to inject steam in the tangential direction or radial direction of the cross section of the flow channel at and/or in the vicinity thereof. Device for promoting the solubilization of organic matter. The fluid nozzle is a venturi tube nozzle having a throat, and the steam injection nozzle has a channel cross-sectional area that is a cavitation generation region in the throat and/or the fluid nozzle defined by the following formula (1). 2. The device for promoting solubilization of organic substances according to claim 1, wherein the device is provided at position A.
Ath≦A≦Q×(0.5×ρ÷ΔP) ^0.5 (1)
However, Ath: cross-sectional area of the throat A: cross-sectional area of the flow path in the cavitation region Q: flow rate of the liquid substance ρ: density of the liquid substance ΔP: the ratio between the outlet pressure of the venturi tube nozzle and the saturated vapor pressure of the liquid substance Pressure difference 3. The apparatus for promoting solubilization of organic matter according to claim 1, wherein the steam injection nozzle is an integrated Laval type nozzle in which the inside of the nozzle is continuous from the tapered portion to the diverging portion .

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