JP2008289992A - Method and apparatus for deodorization - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and an apparatus for deodorization effective as a measure against odors emitted when odorant sources stored in a hopper are discharged out of the hopper. <P>SOLUTION: The method and apparatus are used to deodorize odors produced around facilities when odorant sources stored in the hopper are discharged out of the hopper. A first spray nozzle 11 is arranged in the periphery of the discharge door of the hopper: when the discharge door of the hopper is opened, a deodorant is sprayed from the spray nozzle. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a deodorizing method that can suitably deodorize a malodor source stored inside a hopper to a malodor that is generated when the odor source is carried out of the hopper, and a deodorizing apparatus for performing the deodorizing method.

  Sulfur, sewage treatment, paper mills, food factory wastewater treatment, etc., sulfur substances such as hydrogen sulfide and methyl mercaptan, fishery wastewater treatment, amine substances, garbage treatment plants etc., fatty acid substances such as isovaleric acid, livestock facilities And malodorous substances such as ammonia are generated at compost plants. Often, malodorous substances generated from these establishments diffuse into the neighborhood and cause odor pollution. As a countermeasure against these odorous substances, many facilities try to reduce odors by using deodorization equipment such as activated carbon adsorption and biological deodorization, but places where strong odor sources are discharged to the outside, such as dewatered cake in the sewage facility sludge treatment process inside the hopper When storing and transporting it to the outside, it is difficult to deodorize by deodorizing equipment because malodorous substances such as hydrogen sulfide diffuse at a high concentration of several tens to several hundred ppm or more into the work space. Insufficient deodorization diffuses bad odors into the work space, so there are many cases where the work environment in the facility deteriorates or leaks outside the facility, causing odor pollution to the neighborhood.

In order to cope with such a problem, a method of suppressing the generation of malodorous substances by adding a deodorant to wastewater or sludge that is a source of malodor has been proposed (Patent Document 1). However, when the odor source stored inside the hopper is discharged to the outside, such as when the odor is strong, even if these methods are taken, a sufficient deodorizing effect may not be achieved. In addition, in order to suppress the generation of malodor, a deodorant must be added to the entire malodor source to some extent, which is a problem that the amount used is increased.
JP 2001-300545 A

  An object of the present invention is to provide an effective deodorization method as a countermeasure against bad odor when discharging a bad odor source stored inside the hopper to the outside of the hopper.

As a result of repeated studies on the application form of the deodorant in order to solve the above problems, the inventors of the present invention, against the odor when the odor source stored inside the hopper is discharged outside the hopper, the outer periphery of the hopper discharge door The inventors have found that a high deodorizing effect is exhibited by spraying a deodorant when the discharge door is opened, and the present invention has been completed. That is, the present invention is as follows.
1. A deodorizing method for discharging a bad odor source stored inside a hopper to the outside of the hopper, wherein a first spray nozzle is disposed on the outer periphery of the discharge door of the hopper, . The deodorizing method characterized by spraying a deodorizer from the spray nozzle.
2. In addition, a second spray nozzle is disposed inside the hopper, and the deodorizer is sprayed from the second spray nozzle when the discharge door is opened. Deodorization method of description.
3. The spraying on the outer periphery of the discharge door is started before the discharge door is opened. Or 2. Deodorizing method as described in 4.
4). 1. The spraying to the outer periphery of the discharge door is performed even after the discharge door is closed. ~ 3. Deodorizing method according to any one of the above.
5. A deodorant tank, a pump for supplying the deodorant from the deodorant tank to the pipe, a plurality of first spray nozzles connected to the pipe and provided on an outer periphery of the discharge door of the hopper, and the discharge door A deodorizing apparatus comprising: a control device that drives the pump to spray the deodorant from the first nozzle when the gas is opened.
6). The apparatus further comprises a second spray nozzle connected to the pipe and provided in the hopper, and the control device also controls spray from the second nozzle. Deodorizing apparatus described in 1.
7). The control device includes a control mechanism that controls ON / OFF of the spray based on an external input. Or 6. Deodorizing apparatus described in 1.
8). The discharge door opening / closing detection device is provided, and the control device includes a control mechanism for controlling ON / OFF of the spray based on a signal from the opening / closing detection device. . Or 6. Deodorizing apparatus described in 1.
9. The control device further includes a timer that controls the spray time of the deodorant, and a control mechanism that controls ON / OFF of the spray based on a signal from the timer. Said 5. ~ 8. Deodorizing apparatus according to any one of the above.

  A high deodorizing effect can be obtained with a relatively small amount of deodorant. As a result, the work environment can be improved, odor pollution can be suppressed, and the amount of deodorant used can be reduced.

  The present invention will be specifically described below. Odor sources include wastewater from wastewater treatment plants, sewage treatment plants, livestock, garbage disposal plants, paper mills, food factories, etc., wastewater treatment processes, sludge, dehydrated cakes, and other general garbage and garbage. In addition, those that generate a strong odor such as yeast residue and raw material residue, or those that generate a strong odor when stored. The hopper is a device such as a container or a tank for temporarily storing these malodorous sources (reserved materials), and a device having a discharge door for discharging the stored materials by gravity or a screw at the lower part. Say.

  When the odor source is discharged from the inside of the hopper to the outside, the odor substance diffuses into the discharged space. This is the case when malodorous sources are moved to transport trucks, containers, etc. At this time, by properly spraying the deodorant, the amount of malodorous substances diffused can be reduced, and the amount of malodorous substances diffused into the discharge space can be reduced. Improve the working environment and prevent the spread of malodorous substances outside the facility.

  As the deodorant that can be applied to the present invention, a wide range of deodorants that can reduce the malodor concentration by contact with the target malodorous substance can be used. It is preferable that it is a chemical | medical agent which has a deodorizing effect on nitrogen-type malodorous substances, such as sulfur-type malodorous substances, such as hydrogen sulfide and methyl mercaptan, fatty acid-type malodorous substances, amines, and ammonia which are typical as malodorous substances. Moreover, generally known natural deodorants and chemical deodorants can be used as deodorants. Examples of natural deodorants include wood vinegar, green tea and cypress extracts, plant extracts such as conifers and soybeans, soybean oil derivatives, plant extracts containing flavonoids and terpenes, essential oils, and the like.

  Chemical deodorants include aldehyde compounds such as formaldehyde, glyoxal, glutaraldehyde, malonaldehyde, benzaldehyde, succinaldehyde, and malealdehyde, oxocarboxylic acids such as glyoxylic acid and pyruvic acid, oxalic acid, citric acid, and malonic acid , Succinic acid, glutaric acid, adipic acid, pimelic acid, fumaric acid, methyl malic acid, isocitric acid, tartaric acid, gluconic acid, maleic acid, methyl maleic acid, methyl fumaric acid, itaconic acid, acetylenic acid, malic acid, formic acid, acetic acid , Lauric acid, linoleic acid, oleic acid, acrylic acid, polyacrylic acid, hydroxyacetic acid, sorbic acid, lactic acid, alginic acid, aspartic acid, glycine and other aliphatic carboxylic acids, benzoic acid, nicotinic acid, gallic acid, abietic acid , Cinnamic acid, fu Aromatic carboxylic acids such as phosphoric acid, terephthalic acid, trimellitic acid, and halogen-substituted esters of these organic acid compounds, alkali metal salt compounds and acid anhydrides, methacrylic acid esters such as lauryl methacrylate, and maleic acid such as dimethyl maleate Unsaturated ester compounds such as esters, organic nitrogen compounds such as monoethanolamine, diethanolamine, and triethanolamine and their salts, inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium bicarbonate, calcium carbonate, sulfuric acid , Inorganic acids such as phosphoric acid and hydrochloric acid, iron compounds such as divalent iron, manganese compounds such as potassium permanganate and manganese dioxide, titanium oxide, zirconium oxide, silicon oxide, calcium oxide, aluminum oxide, alum, sulfuric acid Armini , Copper sulfate, zinc carbonate, zinc sulfate, zinc chloride, nickel, tin, lead, cobalt, platinum, palladium, silver, molybdenum, ruthenium, strontium and other metal compounds, hypochlorous acid, sodium hypochlorite, chlorine Acid salt, chlorite, chlorine dioxide, chlorine, salicin powder, chlorine compounds such as chlorinated isocyanuric acid, peroxides such as hydrogen peroxide, sodium percarbonate, calcium peroxide, ozone, hydrogen, hydrogen perboron Compounds, aluminum hydroxide compounds, sodium sulfite, sodium nitrate, sodium nitrite, hydrogen iodide, hydrazine and other redox agents, ethylene oxide, propylene oxide, butylene oxide and other epoxide compounds, cyclodextrins and other dextrin compounds, lauryl dimethyl Betaine compounds such as aminoacetic acid betaine, benzal chloride Substances such as cationic surfactants such as cornium and benzethonium chloride, amphoteric surfactants such as betaine type and glycine type surfactants, and surfactants such as anionic surfactants and nonionic surfactants can be widely used. .

  These may be used alone or as a mixture of a plurality of substances. In particular, a deodorant containing a betaine compound, glyoxal, or glyoxylic acid is more preferable in terms of a wide range of deodorizing effects, safety, and handleability. Adding an aromatic component such as essential oil to the deodorant is effective in that it can functionally remove malodorous substances that cannot be completely removed.

  In order to enhance the deodorizing effect by the neutralization reaction, those containing a pH adjusting agent can also be suitably used. For acidic odors such as hydrogen sulfide and organic acid odors, neutral to alkaline deodorants are effective. For alkaline odors such as amine and ammonia, acidic deodorants are effective. The pH adjustment range can be set according to the acid alkalinity of the target malodorous substance, preferably in the range of pH 3.0 to 10.0, and in the range of pH 6.0 to 9.0 in terms of use environment such as corrosivity and handleability. More preferred. As the pH adjuster that can be used, any deodorizing component described above can be used as long as it dissolves in water and exhibits acidity and alkalinity. Malic acid, potassium hydrogen malate, malic acid, which are designated as food additives, can also be used. Sodium tartaric acid, sodium tartrate, potassium hydrogen tartrate, sodium tartrate, calcium tartrate, potassium bitartrate, adipic acid, ammonium adipate, potassium adipate, sodium adipate, ammonia water, potassium alum, carnauba wax, carnauba wax, citric acid, Calcium citrate, trisodium citrate, glucono delta lactone, gluconolactone, sodium gluconate, magnesium gluconate, succinic acid, monosodium succinate, disodium succinate, soda ash, fumaric acid, potassium fumarate, fumar Calcium phosphate, sodium fumarate, monosodium fumarate, Brazil wax, alum, phosphoric acid, magnesium phosphate, monopotassium phosphate, monosodium phosphate, diammonium hydrogen phosphate, dipotassium hydrogen phosphate, hydrogen phosphate Disodium, diammonium phosphate, dipotassium phosphate, disodium phosphate, potassium dihydrogen phosphate, sodium dihydrogen phosphate, ammonium bicarbonate, sodium bicarbonate, heavy carbon soda, calcined alum, ammonium acetate, calcium acetate , Sodium acetate, ammonium carbonate, potassium carbonate, carbon dioxide, sodium carbonate, ammonium bicarbonate, sodium bicarbonate, carbon soda, lactic acid, ammonium lactate, sodium lactate, potassium aluminum sulfate, adipic acid, itaconic acid, glycine, repose Sodium, sodium hydroxide, potassium hydroxide and the like can be more suitably used.

  The amount of the deodorant sprayed depends on the deodorizing ability of the applied deodorant and the reactivity with the target malodorous substance, and the more the deodorizing effect can be enhanced. The total amount of the deodorant sprayed on the malodorous source is preferably 0.01 to less than 1% by weight of the malodorous source weight, and more preferably 0.1 to 0.6% by weight from the viewpoint of an increase in the malodorous source weight. The deodorant can be used after being diluted to the extent that the deodorizing effect is not lost when sprayed. The dilution factor is preferably selected in consideration of the increase in the malodor source weight after spraying and the cost of using the deodorant because the amount of the deodorizing active ingredient relative to the amount of the spray liquid decreases due to dilution.

  A plurality of spray nozzles for spraying the deodorant are disposed on the outer periphery of the hopper discharge door (these spray nozzles are referred to as first spray nozzles). Here, the outer periphery means a peripheral portion in the vicinity of the discharge door, and it is preferable to surround the malodorous source so as to be as small as possible. The arrangement number of the first spray nozzles per discharge door can be determined in consideration of the size of the spray application area, the spray cover range of the application nozzles, and the like. At this time, it is more preferable to install the first spray nozzle so that the spray cover ranges sufficiently overlap. Thereby, the mist barrier by a spray deodorant can be made and the deodorizing effect can be improved.

  Spraying is performed when the hopper discharge door is opened, but spraying itself may be performed manually, or automatic spraying may be performed in conjunction with the opening / closing control of the discharge door. Moreover, the time of opening means the time when the discharge door is actually opened, but it does not stop there and includes a certain time range in which the discharge doors before and after that are closed. In other words, the deodorant may be sprayed after the hopper discharge door is opened, but before the hopper discharge door is opened, the deodorant is sprayed in advance in the open space of the odor source discharged from the hopper. It is preferable to leave it because the deodorizing effect can be further enhanced. The spray start time when the deodorant is sprayed before the hopper discharge door opens can be set backward from the time when the hopper discharge door starts to open, and only the deodorant droplet floating time (time required for dropping) The time required for the deodorant droplets to float before the hopper discharge door opens is the time required for the deodorant droplets discharged from the nozzle to land on the floor of the spray space. Say.

The theoretical value of the deodorant droplet floating time is that water (fluid density 1000 kg / m ³ ) particles are in air (fluid density 1.2 kg / m ³ , fluid viscosity coefficient 1.8 × 10 ⁻⁵ Pa · s). Assuming that the initial falling velocity of water particles is equal to the final velocity when falling and the falling distance is 3 m, the theoretical floating time of the deodorant droplet particles is about 1.5 seconds when the average particle diameter is 500 μm. When the average particle size is 200 μm, the time is about 4 seconds, when the average particle size is 100 μm, the time is about 10 seconds, when the average particle size is 50 μm, the time is about 40 seconds, and when the average particle size is 10 μm, the time is about 1000 seconds. Since the droplets discharged from the nozzles at this time have a considerable particle size distribution, the average particle size is used for the calculation. As described above, the particle floating time becomes longer because the drop speed becomes slower as the particle size of the deodorant droplet becomes smaller. When the particle diameter is 0.5 μm or less, the dropping speed is 7.56 × 10 ⁻⁶ m / s or less, which is less than the moving distance due to the Brownian motion, and thus does not fall. However, the particle size of the deodorant droplets discharged from the spray nozzle actually has a certain particle size distribution, and there are also external factors such as air flow, so the deodorant droplet floating time will be shorter than the theoretical value. There is also.

  From the above, the spray start time is preferably set before the hopper discharge door is opened within the range of 1.5 seconds to 1000 seconds, which is a theoretical calculation value when the average particle diameter is 10 μm or more and less than 500 μm. Is more preferably in the range of 1.5 seconds to 300 seconds. Further, when the average particle diameter is less than 10 μm, it is preferable to set it within 1000 seconds at the longest, and when it is 500 μm or more, it is preferable to set it within 1.5 seconds from the viewpoint of reducing the amount of deodorant used and workability.

  Also, spraying the deodorant for a certain period of time after the hopper discharge door is closed is preferable because it can reduce the malodorous substance diffused outside the hopper and enhance the deodorizing effect. The time to continue spraying the deodorant immediately after the hopper discharge door is closed depends on the deodorizing effect of the deodorant used, but the time is sufficient to remove the amount of malodorous substances to the desired deodorizing level. What is necessary is just to set to the time which can reach | attain the level which the target malodorous substance density | concentration reaches the measurement detection lower limit as a standard. The lower limit of detection is preferably less than a level measurable with a commercially available gas detector tube or a malodor measuring device capable of detecting malodorous components. It is practically preferable that the longest spraying time after the hopper discharge door is closed is 15 minutes or less.

  In addition to spraying the outer periphery of the hopper discharge door, the deodorant can be efficiently deodorized by providing a spray nozzle inside the hopper and spraying the deodorant (this spray nozzle is the second spray nozzle). Called). For example, in the case of discharging the dewatered cake (stored amount 9 tons) stored in the dewatered cake hopper (maximum weight 10 tons) of the sewage treatment plant, the cake stored in the hopper is stored, so that hydrogen sulfide or Odorous substances such as methyl mercaptan are generated. The amount of these malodorous substances generated increases as the cake (bad odor source) is compressed near the bottom of the cake stored in the hopper and the bottom of the hopper and is easily shielded from the outside air, so that decay and anaerobic progress. However, malodorous substances are confined in the cake when stored, and are difficult to diffuse outside. In many cases, the upper space of the hopper is deodorized by the exhaust duct and the deodorizing equipment is installed. If it is operating normally, there are few problems with bad odor.

  However, when the cake when the dehydrated cake is discharged collapses, the malodorous substance diffuses into the atmosphere and becomes malodorous. At this time, the dehydrated cake, which is a source of malodor, moves to a truck or container for external discharge, but the malodorous substance also accumulates in the discharge space or inside the hopper. These phenomena were clarified from the measurement of the concentration of malodorous substances when the malodorous source was discharged from the hopper. This means that there is a malodorous substance that can also be called a second malodorous source in the empty hopper after the malodorous source is discharged. This second odor source is that when the remaining amount of dehydrated cake in the hopper to be discharged is close to 50% by weight of the maximum weight of the hopper (5 tons remaining), the cake that has formed a bridge in the hopper collapses and the outside of the hopper A through-hole (air passage) is created, and the cake diffuses to the outside of the hopper until the discharge of the cake is completed and the hopper discharge door is completely closed. If the malodorous source is dispersed, the amount of deodorant used for deodorization will increase, but by dividing the spray of the deodorant and spraying the deodorant inside the hopper, the absolute amount of the second malodorous source can also be obtained. If it can be reduced, more efficient deodorization can be achieved. As described above, the deodorant spray in the hopper focuses on the second malodor source in the hopper that has been overlooked so far and more efficiently performs the deodorization when the malodor source is discharged from the hopper.

  The installation position of the second spray nozzle in the hopper is preferably provided in the upper part of the hopper internal space because it is difficult to contact the stored substance and the deodorant can be sprayed widely in the hopper. The number of nozzles arranged is sufficient if the deodorant is sufficiently diffused in the hopper, and can be determined by the size of the hopper and the nozzle used (average particle size of the deodorant to be sprayed). A plurality may be arranged.

  The spraying time of the spray inside the hopper may be performed simultaneously with the spray around the hopper discharge door when the hopper discharge door is opened when the odor source is discharged, but when the odor source storage weight exceeds 50% by weight of the maximum hopper storable weight It is more preferable to spray when the amount of the hopper is less than 50% by weight of the maximum storable weight from the viewpoint of reducing the amount of spray deodorant used. Although spray control can also be performed manually, it is preferable from the viewpoint of workability that automatic control is performed based on the weight of the weigher in the hopper. In the case of automatic control, spraying may be started automatically when the remaining amount of odor source in the hopper reaches the set weight, and spraying may be stopped when the hopper discharge door is closed. A mechanism that can be arbitrarily set according to the remaining amount of bad odor source may be incorporated in the spray control device.

  The deodorant sprayed by spraying around the hopper discharge door and spraying inside the hopper can be applied in different types, but the same deodorant shares the deodorant tank, pump, spray equipment line and small equipment This is practical because

  Here, with reference to drawings, the deodorizing apparatus for implementing said deodorizing method is demonstrated. FIG. 1 is a conceptual diagram showing a schematic configuration of a deodorizing apparatus relating to a one-fluid spray of a deodorant. The deodorizing apparatus in FIG. 1 includes a plurality of first fluid spray nozzles 11 and a plurality of second fluid spray nozzles 12, a deodorant tank 13, a pump 14, and a pump 14 to a deodorant valve 16. , A pipe extending to the first or second spray nozzle, a pipe connecting the pump and the deodorant tank, a pump drive control, and a control for controlling the spray ON / OFF by the deodorant valve 16 The apparatus 15 constitutes a main part related to spraying. In order to spray the deodorant, the deodorant stored in the deodorant tank 13 is discharged into the pipe by the pump 14 and pressurized. The pressurized deodorant is discharged from the one-fluid spray nozzles 11 and 12. Spray ON / OFF control is performed by controlling the pump drive by the control device 15 and opening / closing the deodorant valve 16 in the case of one fluid spray. The deodorant valve 16 may be opened and closed manually.

  FIG. 2 is a schematic view showing a configuration of a deodorizing apparatus related to two-fluid spraying of a deodorant. A plurality of first two-fluid spray nozzles 21, a plurality of second two-fluid spray nozzles 22, a deodorant tank 23, a pump 24, an air compressor 27, and the pump 24 via a deodorant valve 26. A pipe that leads to the first or second spray nozzle, a pipe that connects the pump and the deodorant tank, and a pipe that leads from the air compressor 27 via the air valve 28 to the first or second spray nozzle. The main part related to the spraying is constituted by the control device 25 for controlling the pump drive and the ON / OFF control of the spraying by the deodorant valve 16 and the air valve 28. The deodorant stored in the deodorant tank 23 is discharged by the pump 24 and supplied to the deodorant spray nozzles 21 and 22. The deodorant is discharged into the pipe by a pump in the same manner as in the apparatus of FIG. 1, further mixed with the compressed air supplied from the air compressor 27, and discharged from the two-fluid spray nozzles 21 and 22. The spray control of the first spray and the second spray is performed by opening / closing control of the deodorant valve 26 and the air valve 28 by the control device 25. Note that the opening / closing control of the deodorant valve 26 and the air valve 28 may be performed manually.

  The operation of the deodorizer is performed by turning on and off the pumps 14 and 24 which are spraying power sources in the one-fluid deodorizer and the two-fluid deodorizer, respectively. Control is performed by control devices 15 and 25 that perform opening and closing control. The control devices 15 and 25 can be provided with a control mechanism such as a switch for turning the spray ON / OFF by an external input such as manual operation. In addition, a discharge door open / close detection device is installed to link the spray with the open / close control of the hopper discharge door, and a control mechanism is provided to turn on / off the deodorant spray based on a signal from the open / close detection device. May be. In addition, it has a timer that controls the spray time such as spray start time, spray duration time, spray end time, etc. of the deodorant, and a control mechanism that controls ON / OFF of the spray based on the signal from this timer. Also good.

  Spray control can be used by combining these control mechanisms in combination. For example, spraying is manually turned on before opening the hopper discharge door, and then the spray control is transferred to the linked spray control when the hopper discharge door is opened. It is also possible to perform control such that the spray is automatically turned off after the timer set time has elapsed since the closing of. These deodorant spray control switches and the like may be installed at a position where they can be easily operated outside the control device, or may be remotely controlled.

  As the spray nozzle, a known nozzle can be used without particular limitation. It is preferable to spray with a droplet of 1 to 1000 μm from the viewpoint that the contact area between the sprayed droplet and the malodorous substance is increased and the reaction efficiency is increased as the nozzle capable of fine spraying, and spraying with a droplet of 1 to 500 μm is more preferable. preferable. As the spray nozzle type, a commercially available one-fluid spray nozzle or a two-fluid spray nozzle that simultaneously discharges compressed air and a deodorant using a compressor can be used. The material, spray pattern, spray angle, and the like of the spray nozzle are not particularly limited, and may be selected according to the spraying location. The 1-fluid spray nozzle is effective in terms of downsizing the equipment because the spray power source can be only a pump, and the 2-fluid spray nozzle is particularly deodorized because the spray droplet diameter can be easily reduced. This is effective when the space volume is large.

  As the spray pump, in the case of one-fluid spray, a high-lift pump that can be operated at a discharge pressure of 0.5 to 5 MPa, such as a spiral pump, a magnet pump, or a diaphragm pump, can be suitably used. In the case of two-fluid spray, any pump can be used as long as it can discharge a flow rate corresponding to the target spray amount, and a metering pump with less pulsation can be used particularly preferably.

  The deodorant spray amount of the deodorant spray on the outer periphery of the hopper discharge door and the deodorant spray on the inside of the hopper can be adjusted by providing a flow rate adjusting mechanism such as a flow rate adjusting valve. The amount of spray can be adjusted by the number of spray nozzles, the amount of spray, and the level of spray pressure. In order to prevent clogging of the spray nozzle, it is effective to install a filter in the deodorant line leading to the spray nozzle. Moreover, it is preferable to install a pressure gauge or a flow meter in terms of adjusting the spray amount. Further, a check valve may be provided for the purpose of not removing the deodorant in the deodorant pipe in order to speed up the response of the spray start. In order to prevent liquid dripping from the nozzle, an electromagnetic valve may be installed in the deodorant spray line, and a deodorant liquid drain (residual pressure release) mechanism that controls to open after spraying is stopped may be provided.

  The method of surrounding the outer periphery of the hopper discharge door with a curtain or sheet to improve the deodorizing efficiency of the spray deodorant has the effect of suppressing the spread of malodorous substances and deodorant droplets widely in the space. It has an effect of increasing the contact efficiency between the deodorant and the malodorous substance, and is effective. Also, the method of heating and spraying the deodorant is effective because it has the effect of increasing the reactivity between the deodorant and the malodorous substance. Similarly, it is also effective to increase the deodorant spray environment temperature with a temperature controller or the like.

  The deodorizing method or deodorizing apparatus according to the present invention can be used in combination with other deodorizing techniques such as other deodorant addition methods and spraying methods. For example, it can be applied to a method of increasing the deodorization level by combining the method of reducing the amount of malodor generated when a deodorant is added to the odor source in advance and discharged from the hopper, and this deodorization method. .

  The present invention will be described below based on examples and comparative examples, but the present invention is not limited to these specific embodiments. Preconditions of the examples and comparative examples are as follows.

  A deodorizing device was installed in the dewatered cake storage hopper of the A sewage treatment plant, and the deodorizing effect was measured by spraying a deodorant when discharging the dewatered cake to the outside of the hopper. The maximum storage weight of the cake hopper is 10 tons, and the amount of dewatered cake discharged per time is 9 tons.

  The determination of the deodorizing effect was performed on the basis of the concentration of hydrogen sulfide which was the main malodorous substance among the malodorous substances generated. The hydrogen sulfide concentration was measured by a diffusion hydrogen sulfide measuring instrument (trade name: GHS-7AT) manufactured by Gastec Corporation. A sensor range of 0 to 100 ppm was used. The logging interval was set at 1 minute, and calibration with hydrogen sulfide gas was performed before measurement. The sensor installation position is close to the outside of the hopper discharge door (hereinafter referred to as sensor position A), inside the hopper suspended from the top of the hopper (hereinafter referred to as sensor position B), and the cake unloading chamber where the hopper is installed. The measurement was performed in a work space near the entrance (hereinafter referred to as sensor position C).

The deodorizing agent was sprayed using a deodorizing apparatus having the same configuration as the deodorizing apparatus shown in FIG. 1 or 2, which is composed of a spray nozzle, a pump, piping, and a tank. The spray nozzle uses UniJet spray nozzle TP800005-SS (hereinafter referred to as spray nozzle a) and KYNARVeeJet spray nozzle HBU-KY12002 (hereinafter referred to as spray nozzle b) manufactured by Spraying Systems Japan Co., Ltd. The pump used was Nikuni 20NED07Z. As the deodorant, a commercially available deodorant (trade name: Shutter SR250FS, manufactured by Asahi Kasei Clean Chemical Co., Ltd.) containing an organic acid salt and a surfactant was used.
[Example 1]

A deodorizing apparatus having the same configuration as that of the deodorizing apparatus shown in FIG. 1 was used except that the second spray nozzle 12 was not used. 28 spray nozzles a are arranged as the first spray nozzle 11 so as to surround the outer periphery of the discharge door of the hopper, and the deodorant spray is applied when the hopper discharge door is opened (the time from when the hopper discharge door is opened until it is closed). The liquid volume was adjusted to 7.5 L / min and sprayed. Table 1 shows the hydrogen sulfide peak values at the sensor positions A, B, and C at this time. Hydrogen sulfide concentration could be greatly reduced, and high deodorization results were obtained.
[Example 2]

A deodorizing apparatus having the same configuration as the deodorizing apparatus shown in FIG. 1 was used. The first spray nozzle 11 is the same as that of the first embodiment, and two spray nozzles b are arranged diagonally toward the center of the hopper at the upper position of the hopper inner space as the second spray nozzle 12. When the hopper discharge door is open (the time from when the hopper discharge door is opened until it is closed), the total amount of deodorant sprayed from all spray nozzles is adjusted to 7.5 L / min. Sprayed. The ratio of the spray amount on the outer periphery of the hopper discharge door and the spray amount inside the hopper was set to 3: 1. At this time, the hydrogen sulfide peak values at the sensor positions A, B and C are shown in Table 1. Better deodorization results were obtained than in Example 1. When the spray is divided into the outer periphery of the hopper discharge door and the inside of the hopper, it can be seen that a higher deodorizing effect is exhibited even when the spray amount of the deodorant is the same as that in the case of only the outer periphery.
[Example 3]

Deodorizing treatment was performed in the same manner as in Example 2 except that the deodorant spraying on the outer periphery of the hopper discharge door was performed 5 seconds before the hopper discharge door opened. At this time, the hydrogen sulfide peak values at the sensor positions A, B and C are shown in Table 1. The hydrogen sulfide peak was sufficiently low, and a high deodorizing effect was obtained.
[Example 4]

Deodorant spraying on the outer periphery of the hopper discharge door was performed in the same manner as in Example 2 except that spraying was continued for 10 seconds after the cake discharge was finished and the hopper discharge door was closed. At this time, the hydrogen sulfide peak values at the sensor positions A, B, and C are shown in Table 1. The hydrogen sulfide peak was remarkably low, and a high deodorizing effect was obtained.
[Comparative example]

  The odor was measured in the same manner as in Example 1 except that the deodorant was not sprayed. At this time, the hydrogen sulfide peak values at the sensor positions A, B and C are shown in Table 1.

It is a schematic diagram which shows the structural example of a deodorizing apparatus. It is a schematic diagram which shows the other structural example of a deodorizing apparatus.

Claims (9)

  A deodorizing method for discharging malodorous sources stored inside a hopper to the outside of the hopper, wherein a first spray nozzle is arranged on the outer periphery of the discharge door of the hopper, and the first spray nozzle is opened when the hopper discharge door is opened. A deodorizing method comprising spraying a deodorant from one spray nozzle.   In addition, a second spray nozzle is disposed inside the hopper, and the deodorizer is sprayed from the second spray nozzle when the discharge door is opened.   The deodorizing method according to claim 1 or 2, wherein spraying on the outer periphery of the discharge door is started before the discharge door is opened.   The deodorizing method according to any one of claims 1 to 3, wherein spraying on the outer periphery of the discharge door is performed after the discharge door is closed.   A deodorant tank, a pump for supplying the deodorant from the deodorant tank to the pipe, a plurality of first spray nozzles connected to the pipe and provided on an outer periphery of the discharge door of the hopper, and the discharge door A deodorizing apparatus comprising: a control device that drives the pump to spray the deodorant from the first nozzle when the gas is opened.   6. The apparatus according to claim 5, further comprising a second spray nozzle connected to the pipe and provided inside the hopper, wherein the control device also controls spray from the second nozzle. Deodorizing device.   The deodorizing apparatus according to claim 5 or 6, wherein the control apparatus includes a control mechanism for controlling ON / OFF of the spray based on an external input.   The discharge door open / close detection device is provided, and the control device includes a control mechanism for controlling ON / OFF of the spray based on a signal from the open / close detection device. The deodorizing apparatus according to 5 or 6.   The control device further includes a timer that controls the spray time of the deodorant, and a control mechanism that controls ON / OFF of the spray based on a signal from the timer. The deodorizing apparatus according to any one of claims 5 to 8.

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