JPS5940729B2 - Intermittent pneumatic transport device - Google Patents

Description

[Detailed Description of the Invention] Currently, municipal waste is collected and transported by garbage trucks, but this poses problems such as high costs due to rising labor wages, pollution problems such as the scattering of bad odors caused by garbage trucks, and traffic congestion, as well as social problems. pneumatic waste transportation systems have been attracting attention as a new alternative collection system.

However, not only pneumatic transportation of municipal waste, but also any pneumatic transportation in general, requires more power (blower W - pressure CP) and air volume (Q)) than other transportation devices (conveyors, etc.). One disadvantage is that the power is large, and the greatest aim of the present invention is to reduce this required power.

In general pneumatic transport as well as waste pneumatic transport, the wind speed within the transport pipe is generally constant.

However, there are those that are designed to locally change the wind speed by changing the horizontal and vertical pipe diameters, or those that are structurally sleeve-type and have steps for horizontal and vertical expansion and contraction, such as grain newmar. .

However, to date, there have been no designs in which the diameter of the pipe is changed over the entire area (section) in order to reduce pressure loss in the acceleration region, or in which a device is installed to control the wind speed and changes.

The equations of motion of objects to be transported, i.e., particles, in these conventional pneumatic transportation devices can be expressed as equations 0 and 0, and if this is shown diagrammatically, it can be expressed as shown in Figure 1. can.

m: Mass of particle Us Two powder particle speed t: Time g Double force Ur: Relative velocity - Ua - TJs Ua = Speed of air γS: Specific gravity of transported object γa: Specific gravity of air Cw: Resistance coefficient d: Particle diameter - Two In the case of ascending transport +: In the case of descending transport, or in the case of bottom-sliding transport such as garbage transport, if the lump is regarded as a single capsule, the equation of motion of the capsule can be expressed as in equation 3, Moreover, if this is shown diagrammatically, it can be expressed as shown in FIG.

Ws: Weight of the capsule C: Speed of the capsule Va: Speed in the transport pipe fs: Coefficient of friction As: Pressure-receiving area of the capsule These ■■■ formulas are all based on basically the same concept, and from these equations of motion, The relationship between particle or capsule velocity and time is as shown by curve 1 in FIG. 3.

According to this figure, the particle (capsule) velocity is thought to change moment by moment over time, and eventually reach a constant steady velocity.

This curve l varies depending on the conditions (particle diameter, particle mass, capsule pressure receiving area, wind speed, drag coefficient, friction coefficient, etc.), but it is an existing fact that it has been introduced in various literature.

In any case, due to the wind speed in the transport pipe, the particles or capsules have an initial velocity of 0, but the initial velocity increases.
and the next dUs dC dt
dt Reception (this is clear from the * mark in Figure 3), final speed Us
t or C1 is reached.

On the other hand, when we show actual measurement curves of pressure drop, distance, and time for pneumatic transport and garbage transportation, Figure 4 shows the interrelationship between pressure drop and distance for continuous transportation, and Figure 5 shows the correlation between pressure drop and distance for garbage transportation (intermittent transportation). The relationship between pressure drop and time is shown in the case of (transportation).

FIG. 5 shows garbage transportation, that is, when a garbage group is transported by a wind speed of Va by opening the discharge valve 32 in which a certain amount of garbage is stored in the chute 31 in FIG. 6, at a specific point 33. The measured time and pressure changes are plotted on an oscillograph.

As is clear from FIGS. 4 and 5, in both cases, either the pressure drop is large during the initial acceleration of transportation, or the pressure rise is large in the initial acceleration region of transportation.

The present invention was made for the purpose of reducing the rapid drop or rise in pressure at the initial stage of transportation as described above, reducing the size of the head of the propeller, and thereby reducing overall power consumption. A transported material supply device is connected to the pipe, and one acceleration adjustment valve is provided in the transport pipe for the required number of transported material supply devices, and the acceleration adjustment valve allows the transport material to be accelerated in the acceleration region. It is characterized by being configured so that the wind speed can be gradually accelerated.

In addition, for a certain transport distance, a certain amount of transported goods,
When transporting by rapid acceleration method and gradual acceleration method, the following relationship holds true.

The energy required for transportation over a certain distance is purely mechanically constant regardless of changes in intermediate states, and therefore, the reduction in transportation pressure due to the gradual acceleration method appears as an extension of the transportation time.

In other words, from an energy standpoint, it goes without saying that the rapid acceleration method and the gradual acceleration method are the same.

However, the present invention characterizes the phenomenon of ΔP1>ΔP2 and aims at reducing the power of equipment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The principle of the present invention will be explained in detail below, and then the embodiments will be explained in detail.

FIG. 8 shows a curve C- shown in FIG.

In FIG. 8, l indicates a curve C- at a constant wind speed, and 13 indicates a constant acceleration curve.

In the present invention, when objects to be transported (capsules, particles, etc.) are transported at a constant wind speed, the particle speed is l, but by accelerating more slowly than this, for example, 11°12.14.
The purpose is to provide a device such as No. 15 that causes less pressure rise than conventional devices.

Now, three representative curves 1, 13, and 15 in FIG. 8 are shown in FIG.

In general, objects to be transported in a transport pipe are transported by the velocity energy due to the wind speed inside the pipe, and as a result, the pressure head at two fixed points (the drop ΔP of the pressure head necessary for transport) appear.

If the diameter of the transport pipe is d, then π 2 Area of the transport pipe 1d Pressure drop between two fixed points ΔP (mm1q)
Force between two fixed points -d2×ΔP Purely mechanical mass of the transported object m Force for imparting acceleration α F=mα−m and d Ci can be respectively expressed.

Although the flow within the transport pipe is complex, it goes without saying that the pressure drop between two fixed points and F=mα are in a proportional relationship.

In other words, the relationship holds true.

When this relationship is applied to FIG. 10, the relationship shown in FIG. 11 is established.

That is, l (constant wind speed transport, sudden acceleration) → initial pressure loss 3 (wind speed change - uniform acceleration) → constant pressure lS (wind speed change - gradual acceleration) → pressure gradual increase ΔPI>Δ
The following relationship holds: P15>ΔP13.

In this way, the curve 11 located below the 1 curve in FIG.
t12 t 13.14 v 15 are all ΔPF
It is clear that less pressure is required.

Therefore, the main problem of the present invention is how to change the speed of the transported object over an hour, or in other words, change the acceleration so that the curve is located below the curve 1.

Specific examples thereof will be described below based on the drawings.

FIG. 12 is a flow sheet of the entire general municipal waste vacuum suction transportation system.

In the figure, 1 is an inlet, 2 is a dust chute, 3 is a discharge valve, 4 is an air suction valve, 5 is a transport pipe, and 6 is a
Membrane separator (cyclone), 7 is a discharger, 8 is a second stage separator (pack filter), 9 is an air source (blower and motor group), 10 is an air pipe, 11 is a silencer, 12 is an exhaust stack, 13 is a safety valve, 14 is a starting air intake valve, 16 to 19
indicate the dust shoot groups.

FIG. 13 shows details of a conventional dust chute group, and corresponds to an enlarged view of the portion A-D in FIG. 12.

FIG. 14 is a diagram according to an embodiment of the present invention.

Comparing FIG. 14 and FIG. 13, it is found that the dust chute group according to the present invention consists of an inlet 1, a dust chute 2, a discharge valve 3, an air intake valve 4, and a transport pipe 5, which is the same as in the conventional type. The difference from the conventional type is that one acceleration adjustment valve 15 is provided for each of one or more dust chutes 2.

In addition, in FIG. 14, the case where one acceleration adjustment valve is attached to one dust chute 3 is shown by a two-dot chain line,
One acceleration adjustment valve 1 for multiple dust chutes 3
The solid line indicates the case where 5 was given.

In the above configuration, the problem in design is how to size the acceleration regulating valve 15 with respect to the diameter of the transport pipe, and it is desirable to design the acceleration regulating valve 15 so as to satisfy the flow characteristics shown in FIG. 15.

That is, by adjusting the profile of the valve body or the opening/closing speed, the flow rate characteristics are expressed by curves a''c.

Now, when the acceleration adjustment valve 15 is closed (opening degree = 0), the speed of the wind flowing inside the transport pipe 5 is equal to the capacity of the air source 9 Qm37vu'
n, the characteristic curve of the air source 9, and the pipe resistance at that time, and the planned wind speed is va.

Also, the flow rate when the acceleration adjustment valve 15 is fully open is 9 m3//
lll1IL, the flow rate on the upstream side of the acceleration adjustment valve 15 is Qlq, the wind speed is ■a-■b, the flow rate on the downstream side of the acceleration adjustment valve 15 is Q, and the wind speed is Va.

This state can be schematically represented as shown in FIG.

That is, during a certain period of time from when the acceleration adjustment valve 15 is fully opened to when it is fully closed, the wind speed on the upstream side of the acceleration adjustment valve 15 is Va-Vb.
It can be adjusted from to Va.

Therefore, by changing the acceleration adjustment valve from fully open to fully open during the required time t after putting the transported object into the transport pipe 5, the transport wind speed of the transported object can be changed from Va-Vb to Va. This change in wind speed increases the transport speed l(V
11,1 which has a smaller initial pressure loss than (when a is constant)
It is possible to give speed changes such as 2, 13, 14°15.

That is, the object of the present invention can be achieved.

In the above embodiments, the opening/closing time of the acceleration regulating valve 15, the mounting position of the counter valve 15, etc. are a matter of implementation of the present invention, and it goes without saying that they can take various values.

Furthermore, when there are multiple dust chutes, the flow in the transport pipe becomes a plurality of collective flows, but the collective flow after the acceleration adjustment valve is transported at the planned wind speed.

FIG. 17 is another embodiment of the present invention, showing the case of pressure feeding.

In FIG. 17, 20 is a seal valve, 21 is a batch type supply cylinder, 22 is an acceleration adjustment valve, 23 is an exhaust valve, 24 is a balance valve, and 25 is a blower.

In the above explanation, we have mainly shown the effect of reducing pressure drop at the transport start point, but in exactly the same way, acceleration after the bent pipe (acceleration after the transported object has been decelerated at the bent pipe part) ), or acceleration adjustment control in the middle of a transport pipe, such as acceleration in an inclined pipe section.

Since the intermittent pneumatic transport device of the present invention is constructed as described above, it exhibits the following excellent effects.

(1) Since the acceleration adjustment valve is used to gradually accelerate the wind speed in the acceleration region of the transported object, even when accelerating the transport speed of the transported object at the start of transportation or in the middle of the pipeline, it is possible to There is no sudden pressure rise, the pressure head of the blower can be lowered, and therefore the blower requires less horsepower per drive.

(11) According to (1) above, with the same power, the transportation capacity can be increased to a dog.

(iii) The load on the electric source drive prime mover (blower motor) can be kept almost constant.

GV) Since the acceleration adjustment valve is provided on one side for the required number of transported object supply devices, the equipment can be simplified and control can be performed easily.

[Brief explanation of the drawing]

Figures 1 to 7 are diagrams explaining the method of movement of transported objects in general pneumatic transport. Figure 1 is a schematic diagram of a single particle in a vertical riser pipe, and Figure 2 is a capsule sliding at the bottom of the tube. Fig. 3 is a graph showing the curve C-; Fig. 4 is a graph showing the pressure envelope curve at each point in continuous transportation;
The figure is a graph showing a P- curve in intermittent transportation, FIG. 6 is a schematic diagram of a transportation pipeline in intermittent transportation, and FIG. 7 is a pressure comparison graph between the rapid acceleration method and the gradual acceleration method. Figures 8 to 11 are diagrams related to detailed explanation of the present invention, in which Figure 8 is a graph showing C- as a curve, Figure 9 is an enlarged graph of C- as a curve, and Figure 10 is α- as a graph. Graph showing a curve, 1st
Figure 1 is a graph showing a curve of ΔP-. Figures 12 to 17 are diagrams related to embodiments of the present invention, where Figure 12 is a flow sheet of a general municipal waste vacuum collection and transportation system, Figure 13 is an enlarged view of the dust chute section in Figure 11, and Figure 14. 1 is a schematic explanatory diagram showing one embodiment of the present invention.
Fig. 5 is a graph showing the relationship between the opening degree of the acceleration adjustment valve and the wind speed in the pipe, Fig. 16 is a schematic diagram showing the state of change in the flow rate in the pipe and the wind speed, and Fig. 17 is a schematic explanatory diagram showing another embodiment of the present invention. It is. 1...Inlet, 2...Dust chute, 3...Discharge valve, 4...
・Air suction valve, 5...Transport pipe, 15...
・Acceleration adjustment valve.

Claims (1)

[Claims] 1. Connect the transported material supply device to the transport pipe, and connect the transport pipe to the
Intermittent pneumatic transportation characterized in that one acceleration adjustment valve is provided for a required number of transport object supply devices, and the acceleration adjustment valve is configured to gradually accelerate the wind speed in the acceleration region of the transport object. Device.