JP4865125B2 - Roots blower pumping system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention belongs to the technical field of a pressure feeding system using a roots blower that transports a granular material in a transport pipe by an air flow from the roots blower.
[0002]
[Prior art]
For example, in a milling plant that mills wheat into wheat flour, wheat and flour are generally conveyed by a pumping system using a roots blower. In such a milling plant, a plurality of pumping systems are provided for transporting wheat and flour, and root pumps are installed in each pumping system. is set up. On the intake side of the plurality of roots blowers, a filter for purifying air for air transportation and a silencer for eliminating noise generated by the operation of the roots blower are provided for each unit.
[0003]
Here, the clearance between the rotors of the roots blower or between the rotor and the casing is about 100 μm, and if dust of a size larger than this is inhaled, it causes a failure. In addition, a filter is inevitably used in order to prevent dust from entering the object to be transported. However, the filter used is merely a filter for removing dust and is relatively small. It is a simple filter and is often incorporated in a silencer, and its structure is used to remove dust in the air using filter paper or filter cloth (hereinafter referred to as filter medium).
[0004]
Therefore, even if the filter medium becomes dirty or clogged by using a roots blower, it does not have the function of automatically removing dust and the like to clean it. Had to be replaced. In addition, since a small and simple filter is used in this way, the air resistance is unexpectedly large, and the air flow passage speed (F value: unit is (m ³ / min) / m ² = m) / Min) reached 60 m / min to 120 m / min, and energy loss due to filter pressure loss sometimes reached 30% of the total energy consumption.
[0005]
On the other hand, in the prior art, for example, as disclosed in FIG. 3 of JP-A-9-212226, there is a case where a bag filter is used on the suction side of the roots blower in the pneumatic transport device. Are used to prevent the residue of the air-carrying powder particles from being sucked into the roots blower in the suction-type pneumatic transport device or the suction-type pneumatic transport system. When used in a pressure-feed type pneumatic transport system, as shown in FIG. 1 of the above publication, only a filter is installed on the intake side of the Roots blower. It was not known to use a bag filter.
[0006]
[Problems to be solved by the invention]
The present invention has been made in view of the circumstances as described above, and its purpose is to solve the problems of the prior art and to perform periodic manual maintenance for cleaning or replacing the filter medium. It is to provide a pumping system using a roots blower that can greatly reduce the energy loss by reducing the pressure loss caused by the filter and greatly reducing the energy loss.
[0007]
[Means for Solving the Problems]
In order to solve such a problem, a pumping system using a roots blower according to the present invention includes a plurality of roots blowers, a plurality of transport pipes arranged on the exhaust side of each of the plurality of roots blowers, and the plurality of units. A bag filter disposed on the intake side of the roots blower, and a pipe having a plurality of branches for connecting the intake side of the plurality of roots blowers to the exhaust side of the one bag filter. The differential pressure at the air inlet and outlet of the bag filter is 10 mmAq to 300 mm Aq, and the granular material in each transport pipe is transported by the air flow from each roots blower cleaned by the bag filter. It is what.
[0009]
Further, it is preferable that the passing speed of the previous Fang Tsu air flow in the grayed filter positioning the bag filter such that 3 m / min~30m / min.
It is preferable that the bag filter can scrape dust accumulated on the filter medium formed in a cylindrical shape by mechanical vibration or an air flow that flows backward.
Furthermore, it is preferable to have a silencer provided in the piping on the exhaust side of the bag filter.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the pumping system by the Roots blower of this invention is demonstrated in detail based on drawing. In the following description, an example in which a bag filter is used as the above-described air filtering means will be described, but the present invention is not limited to this.
[0011]
FIG. 1 shows a granule pressure feeding system using a roots blower according to an embodiment of the present invention, and specifically shows an air transportation system for supplying wheat to a milling device in a milling plant.
In FIG. 1, 10 is a hopper, 12 is a transport pipe, 14 is a silo, 16 is a roots blower, 18 is a pipe, 20 is a bag filter, 22 is a rotary feeder, 24 is a cyclone, and 26 and 28 are branches. .
[0012]
The pneumatic transportation system described above is a pressure-feeding pneumatic transportation system that transports wheat put into the hopper 10 to the silo 14 by the air current in the transportation pipe 12 and stores it in the silo 14, and represents the first stage of the milling plant. It is what.
In this pressure-feed type pneumatic transportation system, a roots blower 16 is provided as an air source for pneumatically transporting wheat, and a bag filter 20 is installed on the intake side of the roots blower 16 via a pipe 18.
[0013]
Here, in FIG. 1, only one roots blower 16 is shown. However, when the flow rate of air necessary for air transportation is large, a plurality of roots blowers 16 are installed in parallel. Of course you can. In this case, the transport pipe 12 for conveying wheat is connected to the exhaust side of the plurality of roots blowers 16 as described above.
[0014]
A rotary feeder 22 is disposed at the lower end of the hopper 10, and the wheat in the hopper 10 is supplied into the transport pipe 12 by a predetermined amount by the rotary feeder 22. The wheat supplied into the transport pipe 12 is conveyed by the airflow supplied from the roots blower 16 in the transport pipe 12, separated from the airflow by the cyclone 24 at the upper part of the silo 14, and dropped into the silo 14, and actually milled. It is stored in silo 14 until the process is started. When milling, a predetermined amount is supplied to a milling device (not shown) from a feeding device such as a rotary feeder (not shown) provided at the lower end of the silo 14.
[0015]
In addition to this, the milling plant is provided with various pneumatic transportation systems such as conveying milled flour to a stockyard. These pneumatic transport systems also generally use a roots blower pumping system, and the roots blower for these pumping systems is connected to the branches 26 and 28 of the pipe 18 described above.
[0016]
Here, there is only one bag filter 20 that supplies the purified air to the plurality of roots blowers, and the air purified by the bag filter 20 is distributed by the pipe 18 and the branches 26 and 28. It is supplied to each of a plurality of roots blowers by piping (not shown).
[0017]
The capacity of the above-described bag filter 20 has a capacity that can sufficiently supply purified air even when all of the plurality of roots blowers are simultaneously operated. The bag filter 20 has an air flow passing speed (F value) of 40 m / min or less, preferably 3 m / min to 30 m / min when a plurality of roots blowers are operated simultaneously. It is desirable to do.
[0018]
By setting the air flow passage speed (F value) in the bag filter to the above-described value, it is possible to suppress the pressure loss in the pressure feeding system by the Roots blower, and it is possible to greatly reduce the energy loss.
[0019]
Further, in the pumping system using the roots blower according to the present embodiment, it is not usually necessary to provide a silencer, as will be described later. However, when a quiet operation is required for environmental conservation, an arbitrary silencer may be used as necessary. It is desirable to prevent noise from being generated.
[0020]
According to the pumping system using the Roots blower according to the above-described embodiment, the manual maintenance for cleaning or replacing the filter medium, which is the subject of the present invention, is greatly reduced in labor, and the pressure loss due to the filter is reduced. It is possible to realize a pumping system using a Roots blower that reduces the energy loss significantly.
[0021]
That is, as is well known, the bag filter can scrape dust accumulated on the filter medium formed in a cylindrical shape with mechanical vibrations or a reverse air flow, so that the filter medium can be cleaned and replaced regularly. Manual maintenance is not necessary, and labor can be saved significantly.
[0022]
Further, the capacity of the bag filter can be a capacity that can sufficiently supply purified air even when all of the plurality of roots blowers are operated simultaneously. The passage speed (F value) of the air flow in the filter which was about min to 120 m / min can be reduced to 30 m / min or less, and the pressure loss due to the filter can be greatly reduced.
[0023]
Furthermore, noise generated by pressure fluctuations caused by the roots blower can be compensated for when the multiple roots blowers are operated at the same time. Since it is sufficiently large, it becomes possible to drive relatively quietly.
[0024]
Furthermore, with regard to the initial cost of the plant (system), since only one bag filter is used for a plurality of roots blowers, the roots blower has an initial cost compared to the conventional technology in which a filter and a silencer are attached to each root blower. It becomes advantageous as the number of use increases. Accordingly, labor saving and cost reduction are possible.
[0025]
In addition, the said embodiment shows an example of this invention, and it cannot be overemphasized that various improvement etc. may be performed in the range which does not change the summary of this invention.
[0026]
【Effect of the invention】
As described above in detail, according to the present invention, periodic manual maintenance for cleaning and replacing the filter medium is greatly reduced and labor-saving is achieved, and pressure loss due to the filter is reduced and energy is reduced. There is a remarkable effect that a pumping system using a roots blower capable of greatly reducing the loss can be realized.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing a pumping system using a Roots blower according to an embodiment of the present invention.
[Explanation of symbols]
10 Hopper 12 Transport pipe 14 Silo 16 Roots blower 18 Pipe 20 Bag filter 22 Rotary feeder 24 Cyclone 26, 28 Branch

Claims (4)

With multiple roots blowers,
A plurality of transport pipes respectively disposed on the exhaust side of each of the plurality of roots blowers;
One bag filter disposed on the intake side of the plurality of roots blowers;
A pipe having a plurality of branches for connecting the intake side of the plurality of roots blowers to the exhaust side of the one bag filter;
Differential pressure at the air inlet and outlet of the bag filter is 10mmAq~ 300mm Aq,
A pressure feeding system using a roots blower, wherein the granular material in each transport pipe is conveyed by an air flow from each roots blower that has been cleaned by the bag filter.   2. The pressure feeding system using a roots blower according to claim 1, wherein the bag filter is arranged so that a passing speed of an air flow in the bag filter is 3 m / min to 30 m / min.   3. The pressure feeding system using a roots blower according to claim 1, wherein the bag filter can scrape dust accumulated on a filter medium formed in a cylindrical shape by mechanical vibration or an air flow that flows backward.   Furthermore, it has a silencer provided in the said piping in the exhaust side of the said bag filter, The pressure feeding system by the roots blower of any one of Claims 1-3 characterized by the above-mentioned.

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