JP2013203485A - Powder conveyance system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a powder conveyance system that facilitates production of dry air, and prevents a risk of dust explosion, etc. resulting from conveyance of the dry air when conveying powder by means of the dry air.SOLUTION: In a system for conveying powder in a powder mixer 2 into a silo 7 through a first conveyance pipe 5 by means of air conveyance by a blower 6, dry air generated by dry air production device 31 is supplied to the blower 6. The dry air is generated by cooling and dehumidifying outside air in a coil 33a by brine sent from a brine chiller 31. In winter when the humidity of outside air is low, outside air is used as such dry air as it is without being cooled and dehumidified.

Description

  The present invention reduces the moisture content of the powder when pneumatically conveying the powder, making it convenient for transportation and use of the powder after transportation, and eliminating the danger of explosion due to static electricity and maintaining the equipment safely. The present invention relates to a powder conveyance system.

  For example, foods such as salt and sugar, and powders such as charcoal have a property of absorbing moisture, and after absorbing moisture, the quality cannot be sold as it is, and the measurement is hindered. Furthermore, even if they are processed, if they absorb moisture, they form a lump like “dama”. In addition, if these powders containing moisture are transported, they have become a cause of blockage in a delivery part such as a storage tank or in piping. In addition, when these moisture-absorbed powders or lumps adhere to the inner wall of a tank, etc., for those with an open / close lid, the worker scraped off these deposits with a spatula etc. There was also a need for decomposition.

  Therefore, if the inside of the transport system is replaced with low-humidity air and the powder is transported along with the low-humidity air, powder agglomeration, adhesion to the inner walls of tanks and tubes, blockage, and the like can be prevented. Further, even if the powder before being charged into the system contains moisture exceeding the schedule, it can be expected that moisture is transferred to the carrier air during the transportation due to the mass transfer.

  In this regard, conventionally, low-humidity air is used in the powder process, and a quantitative supply device (Patent Document 1) that supplies dry air to a feeder for limestone, the dehumidified air in the feeder, and the feeder An air transport device (Patent Document 2) that is supplied between a hood and a cyclone has been proposed.

  Furthermore, when air is transported using low-humidity air, friction occurs between the powder and the inner wall of the transport system such as a pipe during the transport process, and the pipe is often bent, and the powder is charged. In this state, sparks and the like may cause dust explosion. For this reason, conventionally, there has been a case in which a static eliminator is installed when conveying powder with low-humidity air (Patent Document 3).

JP 2008-290045 A JP 2005-89029 A JP 2010-285238 A

  However, there is no specific description about the supply source of dry air in the device described in Patent Document 1. In this respect, Patent Document 2 uses a so-called dry rotor as a dehumidifier, and uses low dew point air obtained through this dry rotor. However, maintenance and installation of the dry rotor is time-consuming and costly. It was necessary to improve in this respect. And in the thing of patent document 3, in order to prevent that a granular material adheres to the inner wall of a feeder, although the soft X-ray irradiation static elimination apparatus is employ | adopted, the gas to supply is to illustrate carbon dioxide gas Stays.

The present invention has been made in view of the above points, and has improved the supply source of dry air, and further ensures the safety in the above-described low-humidity system accompanying the transfer by dry air. The purpose is to provide.

  In order to achieve the above object, the present invention provides a powder transport system for transporting powder in a powder input section into a target tank by air transport by a blower through a pipe line, The dry air production apparatus for supplying dry air and the powder from the powder input unit to the inside of the target tank, and the powder from the outside of the transfer system pipe line, the powder input unit or the target tank through the soft X-ray transparent body. A soft X-ray irradiation device that irradiates the body with soft X-rays, and the dry air production device dehumidifies outside air using an evaporator of a refrigerator and supplies the air to the blower. It is characterized by that.

  According to the present invention, the dry air to be used for conveying the powder is installed in a factory or facility because the outside air is cooled and dehumidified using the evaporator of the refrigerator and supplied to the blower. An air conditioner refrigerator can be used, and installation of a dedicated dry rotor or the like as in the prior art is unnecessary, and labor and cost can be reduced accordingly. Further, since the soft X-ray irradiation device can neutralize the powder from the outside of the pipeline, tank, etc., it is possible to prevent dangers such as explosion due to static electricity accompanying conveyance with dry air.

  The apparatus has a powder adhesion preventing device that blows dry air against the inner wall of the soft X-ray transmissive body, and the soft X-ray irradiation device is applied to the dry air that is blown against the inner wall of the soft X-ray transmissive body. Alternatively, they may be arranged to irradiate soft X-rays. By adopting such a configuration, it is possible to further prevent the powder from adhering to the inner surface of the soft X-ray transmitting body.

  The soft X-ray transmitting body is made of a transparent material, and the soft X-ray transmitting body is employed in a bent portion of a conveyance system pipeline, and the soft X-ray irradiating device is disposed outside the bent portion. You may do it. For example, bent parts such as elbows tend to be clogged with powder, but by using a soft X-ray transparent material made of a transparent material for such bent parts, such clogging can be confirmed visually. In addition, by irradiating the bent portion with soft X-rays using a soft X-ray irradiation device, charging of the powder can be prevented and clogging itself can be prevented. Therefore, stable operation of the equipment can be realized.

  The dry air production device has a heating device that heats the dehumidified outside air before supplying the blower to the blower, and the heat source of the heating device is steam generated in a factory where the powder conveyance system is installed. May be.

  ADVANTAGE OF THE INVENTION According to this invention, the dry air used for conveyance of powder can be easily obtained using the existing refrigerator, and the danger resulting from static electricity etc. accompanying conveyance with dry air can be prevented. it can.

It is explanatory drawing which shows the outline of a structure of the powder conveyance system concerning embodiment. FIG. 2 is a cross-sectional explanatory view of the vicinity of the upper part of the silo in the powder conveyance system of FIG. FIG. 2 is a cross-sectional explanatory view in the vicinity of a soft X-ray irradiation apparatus provided on the top of a silo in the powder conveyance system of FIG.

  FIG. 1 shows an outline of the configuration of a powder transport system 1 according to an embodiment, and powder to be transported is put into a powder mixer 2. The powder mixer 2 is provided with a stirring device 3 for stirring the powder in the mixer.

  The powder in the powder mixer 2 falls into the first transport pipe 5 through the pipe 4, is pneumatically transported in the first transport pipe 5 by the blower 6, and is transported to the upper part of the silo 7. . The pipe 4 is provided with a rotary valve 4a.

  The powder in the silo 7 falls into the second transport pipe 12 through the pipe 11, is pneumatically transported through the second transport pipe 12 by the blower 13, and is transported to the upper part of the receiver tank 14. The piping 11 is provided with a rotary valve 11a for discharging. Then, the powder in the receiver tank 14 is supplied in a fixed amount to a powder packaging machine 17, for example, through a metering device 16 through a pipe 15. The pipe 15 is provided with a rotary valve 15a.

  The air supplied to the silo 7 through the first transport pipe 5 is sent to the scrubber 23 after passing through the filter 22 from the exhaust pipe 21 connected to the upper part of the silo 7. The exhaust pipe 24 connected to the upper part of the scrubber 23 is exhausted to the outside by the blower 25. The powder in the scrubber 23 is dropped into the container 27 by the pipe 26. The pipe 26 is provided with a rotary valve 26a.

  The air supplied to the receiver tank 14 through the second transfer pipe 12 joins the exhaust pipe 21 connected to the upper part of the silo 7 from above the receiver tank 14, and passes through the exhaust pipe 21. , And sent to the scrubber 23.

  In the example of FIG. 1, the blower 25 may be set so as to be activated upon detection that the system pressure has abnormally increased.

  The dry air production apparatus 31 according to the present embodiment uses the cold heat of the frozen brine of the blownler 32. The brachinler 32 can be an evaporator of a refrigerator. The frozen brine from the blownler 32 is sent to the coil 33a of the air conditioner 33. The coil 33a exchanges heat with the outside air, and cools and dehumidifies the taken outside air. For example, the dew point temperature of the introduced outside air can be reduced to 4 to 5 ° C. The dehumidified outside air is sent as dry air to the blowers 6 and 13 by the fan 33b. If the temperature of the supplied dry air is too low, the quality of the powder to be conveyed is adversely affected. Is supplied to the blowers 6 and 13 after being heated to a predetermined temperature, for example, 20 to 25 ° C. by the heating device 35. In the present embodiment, a heat exchanger that uses steam generated in a factory or facility as a heat source is used as the heating device 35.

  In this embodiment, for example, the chiller outlet temperature of the frozen brine is −3 ° C., whereby the outside air is adjusted to a relative humidity of 35% RH, and the temperature of the dry air is 22 ° C. by the heating device 35. It is set to be.

  In the dry air production apparatus 31, the brine after heat exchange with the outside air in the coil 33 a is returned to the inlet side of the blownler 32 by the pump 38 through the three-way valve 36 and the cushion tank 37. One of the three-way valves 36 is connected between the forward pipe 39 and the return pipe 40 and opens and closes a bypass pipe 41 that bypasses the air conditioner 33. Therefore, when the supply of dry air to the blowers 6 and 13 is unnecessary, the three-way valve 36 is operated and no brine flows through the coil 33a of the air conditioner 33. That is, when the humidity of the outside air is low, such as in winter, the necessary dry air can be produced by operating the three-way valve 36.

  In the present embodiment, a plurality of soft X-ray irradiation devices 51 are provided on the upper surface of the silo 7 as shown in FIG. That is, as shown in FIG. 3, the top surface of the silo 7 is provided with a convex portion 52 that forms a space (a space convex upward when viewed from inside the silo 7), and the top plate of the convex portion 52. The soft X-ray irradiating device 51 is installed outside the convex portion 52 so that the transparent body 53 is provided in the portion and the irradiating unit of the soft X-ray irradiating device 51 is arranged outside the transmitting body 53. However, a part of the side plate of the powder mixer 2 is replaced with a permeator, and a transparent elbow is applied to the dry air flow that is irradiated with soft X-rays facing the supplied dry air or entrained with powder in the transport pipe. You may make it irradiate a soft X ray from an orthogonal direction through.

  As the soft X-ray irradiation device 51, a field emission electron source method using a cold cathode can be used in addition to a filament method using a heated filament as an electron emission source. The transmissive body 53 may be made of a material that transmits soft X-rays. However, if a transparent material is used, the presence or absence and degree of irradiation can be visually observed. Examples of the transparent transmissive body include acrylic, nylon, glass and the like.

  A jet outlet 61 for injecting dry air to the surface of the transmission body 53 is provided inside the transmission body 53 in the convex portion 52. Dry air from the above-described dry air production apparatus 31 is sent to the jet outlet 61 by a blower 63 through a supply pipe 62. The soft X-ray irradiation device 51 is installed with an irradiation angle that can irradiate the entire flow of dry air blown from the jet outlet 61 with soft X-rays.

  The powder conveyance system 1 according to the embodiment has the above-described configuration, and the powder charged into the powder mixer 2 is silo 7 through the first conveyance pipe 5 by air conveyance by the blower 6. Sent in. Depending on the powder to be transported, an appropriate filter may be installed on the upstream side or downstream side of the blowers 6, 13, 63.

  At this time, the air sent by the blower 6 is low-humidity air having a relative humidity of 35% RH, for example, produced by the dry air production device 31, so that the quality of the powder deteriorates due to moisture absorption during transportation. Or it can be prevented from causing clogging.

  The powder sent into the silo 7 is irradiated with soft X-rays by the soft X-ray irradiation device 51 and subjected to charge removal processing. Therefore, dangers such as explosion caused by static electricity associated with conveyance using low-humidity air are prevented. Of course, the subsequent powder transfer from the silo 7 to the receiver tank 14 is also performed by air transfer using low-humidity air having a relative humidity of 35% RH manufactured by the dry air manufacturing apparatus 31, for example. The quality is not deteriorated due to moisture absorption, and blockage does not occur. In addition, since the static elimination process is performed by the soft X-ray irradiation device 51 in the silo 7, there is no danger of dust explosion caused by static electricity.

  Moreover, in the present embodiment, in generating the low-humidity air as described above in the dry air production apparatus 31, the outside air is cooled and dehumidified with the brine of the blownler 32 using the evaporator of the refrigerator. Since low-humidity air is generated, a dedicated dehumidifying device such as a conventional dry rotor is unnecessary.

  Furthermore, since a bypass pipe 41 can be provided between the outgoing pipe 39 and the return pipe 40 of the brachinler 32 and supply of the brine to the coil 33a can be stopped, for example, in the winter season, dry air is not produced. However, when the outside air of low humidity is introduced and can be used as it is as the dry air used for the blowers 6 and 13, it is not necessary to use extra energy and the energy saving effect is high. Such an operation can also be performed by switching the three-way valve 36.

  Further, in the present embodiment, since dry air can be injected from the jet outlet 61 to the inner surface of the transmissive body 53 in the convex portion 52, the powder adheres to the surface of the transmissive body 53, and the soft X It can prevent that the transmittance | permeability of the soft X-ray irradiated from the beam irradiation apparatus 51 falls. Furthermore, in the present embodiment, the soft X-ray irradiation device 51 is installed with an irradiation angle that can irradiate soft X-rays to all of the flow of dry air blown from the jet outlet 61, so that the dry air itself However, static elimination can be performed, and adhesion of the powder to the surface of the transmission body 53 can be more effectively prevented.

  In the above-described embodiment, steam generated in a factory or facility is used as the heat source of the heating device 35. However, the condensation heat of the blownler 32 can also be used. That is, the heat of the refrigerator condenser can be used. For example, in the case of a water-cooled type, the condenser outlet (not shown) and the coil 33a inlet may be connected by a pump and, if necessary, water piping via a cooling tower to circulate. In the case of the air-cooling type, warm exhaust may be received by a hopper or the like and introduced into the coil 33a by an air pipe via a fan. In this case, the coil outlet may be open.

  The coil 33a and the reheating coil of the heating device do not necessarily require the use of the air conditioner 33. A duct unit provided with a filter and an inspection port is provided with a heat insulating material attached as necessary to increase the plate thickness. In addition, these coils 33a and the like may be accommodated. However, in such a case, it is necessary to provide a drain pan and a drain outlet as a countermeasure against condensed water below the coil 33a (cooling coil).

  Further, the air outlet of the air conditioner 33 or the duct unit (not shown) is connected via a pipe to the blowers 6 and 13, but an outside air intake pipe may be provided in the middle of the pipe. As described above, the pipe line can be switched with the outside air intake pipe so that the outside air can be used when the outside air is dry, such as in winter. It can be proposed to perform this switching by measuring outdoor humidity and using an automatic valve. This automatic valve may be provided on two sides of the air conditioner 33 and the duct unit side, or a three-way valve may be used at the position of a merging pipe (a merging portion between the air from the coil and the outside air intake pipe). Further, when the temperature management is important, the joining position with the outside air intake pipe may be upstream of the reheating coil (heating device 35). In the case where an absorption refrigerator is used instead of the brachinler 33, the regenerative heat can be taken out using the cooling water whose temperature has been raised by the absorber.

  In the above embodiment, the soft X-ray irradiation device 51 is installed on the upper part of the silo 7, but it may be provided in a tank or container in which the powder to be neutralized accumulates or in a transport pipe that flows. For example, the powder mixer 2, the first transport pipe 5, and the second transport pipe 12 may be installed outside the surface. By installing on the outside, maintenance of the soft X-ray irradiation apparatus becomes easy. In addition, if a transparent transmission body is provided on the elbow in the pipeline and the soft X-ray irradiation device 51 is installed, it is particularly beneficial for measures against the inside of the sealing mechanism that cannot be easily maintained by an operator. .

  In the system described above, the inside of the transport system such as the first transport pipe 5 and the second transport pipe 12 needs to be maintained at a positive pressure, but the blowers 6, 13, and 63 are, for example, the rotary valve 11 a of the silo 7. The opening may be detected and activated, and the opening may be controlled. In addition, air may be supplied according to an instruction from a pressure gauge installed in the transport system so that the inside of the system is always positive with respect to the outside of the system.

  The blower 6, the powder mixer 2, the silo 7, etc. are each provided in one system. For example, the blower is integrated as one unit in two systems (in that case, the pipe is also branched and integrated using a junction pipe). Or a single blower may be used for backup.

  The present invention is useful when conveying powder by pneumatic conveyance with dry air.

DESCRIPTION OF SYMBOLS 1 Powder conveyance system 2 Powder mixer 3 Stirring device 5 1st conveyance pipe 6, 13, 25, 63 Blower 7 Silo 12 2nd conveyance pipe 14 Receiver tank 21 Exhaust pipe 23 Scrubber 31 Dry air production apparatus 32 Blainchler 33 Air conditioner 33a Coil 35 Heating device 36 Three-way valve 38 Pump 39 Outgoing pipe 40 Return pipe 41 Bypass pipe 51 Soft X-ray irradiation device 53 Permeator 61 Spout

Claims (4)

A powder transfer system for transferring powder in a powder input section into a target tank by air transfer by a blower through a pipe line,
A dry air production apparatus for supplying dry air to the blower;
A soft X-ray that irradiates the soft X-rays to the powder through the soft X-ray transmitting body from the outside of the conveyance system conduit, the powder input unit, or the target tank between the powder input unit and the target tank. An X-ray irradiation device,
The dry air production apparatus cools and dehumidifies the outside air using an evaporator of a refrigerator and supplies the air to the blower. Having a powder adhesion preventing device for blowing dry air to the inner wall of the soft X-ray transparent body;
The soft X-ray irradiation apparatus is arranged to irradiate soft X-rays even to dry air blown against an inner wall of the soft X-ray transmission body. Powder conveying system. The soft X-ray transparent body is made of a transparent material, and the soft X-ray transparent body is employed in a bent portion of a conveyance system pipeline,
3. The powder conveyance system according to claim 1, wherein the soft X-ray irradiation device is disposed outside the bent portion. 4. The dry air production apparatus has a heating device that heats the dehumidified outside air before supplying it to the blower,
The powder transfer system according to any one of claims 1 to 3, wherein the heat source of the heating device is steam generated in a factory where the powder transfer system is installed.

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