JPS5930605B2 - Pressure detection control method in municipal waste pneumatic transportation system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pressure detection control method that can improve the safety and reliability of a municipal waste pneumatic transportation system.

In recent years, pneumatic transportation systems for urban waste have been attracting attention, and studies and technological development are progressing in various fields.

A conventional pneumatic transportation system is shown in Figure 1A.

As mentioned above, there are dust chute methods and intermittent transport methods.

The dust chute system uses a power discharge valve 2at2b that provides a time interval from the dust chute 1a on the downstream side to the dust chutes 1b and 1c on the upstream side.
Dust chutes 1a, 1b, 1c are activated by sequentially operating 2c.
The intermittent transportation method involves supplying waste into the pipeline 3 and transporting it.The intermittent transport method involves sequentially opening the double discharge valves 4 and 5, and supplying the waste into the pipeline 3 and transporting it while giving a time interval. However, in both methods, garbage is supplied into the pipeline at fixed time intervals, so whether a blockage occurs or excessive pressure occurs in the pipeline depends on whether the garbage is supplied into the pipeline or not. It cannot be determined until later, and if the pressure in the pipeline exceeds a certain value as a result of the supply of waste, the safety device will be activated and the supply of waste will be temporarily stopped, or! d It is necessary to shut down the entire system to clean the inside of the pipeline, and if an abnormal phenomenon such as a rise in pressure occurs in the pipeline, it must be dealt with accordingly, resulting in a large loss of time. The system is unreliable because abnormalities cannot be prevented in advance, and the system has various drawbacks.

The present invention was developed with the aim of improving the safety and reliability of transporting waste, which has a wide variety of physical properties, sizes, and specific gravity, and whose flow conditions within pipelines are complex. The total pressure loss within the pipeline is detected by a pressure detector, and the pressure loss within the pipeline is calculated assuming that it will occur due to the next collection of dust that will be supplied into the pipeline from the multiple dust chutes provided in the pipeline.
The estimated pressure loss value and the detected total pressure loss value are summed to calculate the pressure loss in the pipeline due to the entire garbage group, and when the calculated pressure loss is smaller than a predetermined value,
Open the discharge valve of the dust chute scheduled to be supplied next, supply the next group of dust into the pipeline,
When the calculated pressure loss is larger than a predetermined value, the discharge valve is kept closed to extend the time interval of collective garbage supply, and when the pressure loss is smaller than the predetermined value, the discharge valve is opened;
This invention relates to a pressure detection control method in a municipal waste pneumatic transportation system characterized by supplying the waste to the next waste collection pipeline.

Embodiments of the present invention will be described below with reference to the drawings.

11.12, 13.14 in Figure 2 are dust chutes, 1
5.16, 17, 18 are garbage, 19, 20, 21.2 are discharge valves, 23 is pipeline, 24 (d
A separator, 25 is a bag filter, 126 is a pressure gauge, 27 is a suction type air source, 28 is a deodorizer, and the pressure gauge 26 is connected to a comparator 29 shown in FIG.

Now, one group of dust from the dust 15 in the dust chute 11 passes through the discharge valve 19 and enters the pipeline 2.
3 and reaches the position a in Figure 2, it is necessary to accelerate the garbage group to a constant speed, so the pressure loss in the pipeline 23 increases due to acceleration loss, and the garbage group reaches position b When it reaches the position, the pressure loss decreases because it becomes a steady loss.

When reaching C, pressure loss increases due to bent pipe loss, and d9e
Since the waste mass must be lifted up through an inclined section, the pressure loss increases.

When one garbage group is passed through the pipeline 23 in this way, the pressure loss indicated by the pressure gauge 26 changes from time to time, which can be expressed by the following equation.

That is, ΣΔp−Δpa+ΔpM+f1(pI, tt)−−
(1) Here, ΣΔp; Pressure loss Δpa expressed by the pressure detector; Dynamic friction loss ΔpM when air flows through the pipeline; Pressure loss fl (pl ? jl ) of equipment such as separators and bag filters: First Figure 4-a shows how this pressure loss changes.

Next, after a certain time interval ts has elapsed after the first garbage group is transported from the dust chute 11 into the pipeline 23, the second garbage group is supplied from the dust chute 12 into the pipeline 23.

Then, the change in pressure drop in the pipeline 23 due to the two garbage groups is ΣΔp=Δpa+ΔpM+ft (plt t, )
+ f2 (pt t t2) (i
i) It can be expressed as:

Here, f2 (pl, t2); Pressure loss due to the second garbage group The change in this pressure loss is shown in Figure 4.

After the second garbage group is supplied into the pipeline 23 in the same manner, the third garbage group is supplied into the pipeline 23 from the dust chute 13 after a certain time interval ts.

Then, the change in pressure loss in the pipeline 23 due to the three garbage groups is ΣΔp2Δpa+ΔpM+f1(1)t t ”1)
+f2 (pI t j2 ) +f3 (pI
*t3)...(iii).

Here, f3 (pl, t3): Pressure loss due to the third dust group The state of change in this pressure loss is shown in FIG.

Similarly, the pressure loss in the pipeline 23 when the n-th dust group is supplied from the n-th dust chute into the pipeline 23 is as follows: ΣΔp=Δpa+ΔpM+f1 (pt t jt
) +, b (pl, t2) + f3 (pl, t3) +...
... can be expressed as fn(let t tn)-[J.

Here, fn (pl, tn): Pressure loss due to n-th garbage group Next, when the allowable total pressure of the air source 27 is ΔpB, the relationship between pressure loss ΣΔp due to n garbage groups is always ΣΔp ΔpB・...(V).

When the n + 1-th solid dust mass is supplied into the pipeline 23 from the n + 1st dust chute, the pressure loss in the pipeline 23 is as follows: ΣΔp”=Δp1+ΔpM +ft (pt t pt
)+...fn(plttn)+fn+Hp1
, tn+1)...(VD).

Here, fn +1 (pt t t n + 1): n
+ Pressure loss formula due to the first garbage group (VD is ΣΔp'<ΔpB......(VD or ΣΔp'≧ΔpB...) in relation to the allowable pressure ΔpB of the air source 27 ...(■A white relationship is established.

Since the amount of the garbage group supplied from each dust chute at one time is approximately constant, and the pressure p1 immediately after the injection is estimated, f n+ 1 (p, , t n+1) is calculated by the comparator 29. Can be calculated.

However, this f n + 1 (pt t t n +
1), the comparator 29 similarly calculates ΣΔp' and compares the relationship with ΔpB.

If the relationship between ΣΔp' and ΔpB satisfies the relationship (V intermediate), the (n+1)th garbage group is supplied into the pipeline 23 according to a predetermined time interval, but ΣΔp' If ΔpB has the formula relationship (vii'), supplying the (n+1)th garbage group into the pipeline 23 will overload the system, so some of the garbage groups will flow inside the pipeline 23. When the waste has completely passed through and entered the separator 24, and ΣΔp' and ΣpB satisfy equation (vii), the (n+1)th garbage group is supplied into the pipeline 23.

That is, the time interval for supplying the garbage group into the pipeline 23 can be extended from ts to ts+α, and the supply of the garbage group can be adjusted.

Furthermore, from equation (Vii), by calculating the difference between ΔpB and ΣΔp', the time interval ts can be made smaller to increase the transport efficiency.

In the embodiments of the present invention, the case where the garbage group is transported by suction is explained, but it is also possible to adopt the case where the garbage group is transported by a pressure-feeding method. It may be set immediately after
Of course, various other changes may be made without departing from the scope of the present invention.

As mentioned above, the total pressure loss in the pipeline while transporting the garbage group is detected, and the pressure in the pipeline due to this pressure and the next garbage group to be supplied is calculated in advance, and the calculation result is below a certain level. The pressure detection control method in the municipal waste pneumatic transportation system of the present invention ensures that the waste mass can be supplied into the pipeline only when First, it can completely prevent blockage in the pipeline, resulting in safe and reliable operation.

[Brief explanation of drawings]

Figure 1 A2 is an explanatory diagram of the conventional waste transportation method, Figure 2 is an explanatory diagram of the pressure detection control method in the municipal waste pneumatic transportation system of the present invention, and Figure 3 is the pressure detection control of Figure 2. FIG. 4A is a diagram showing the procedure for calculating the pressure inside the pipeline in the method. Figures 1 and 2 are diagrams showing how the pressure loss changes when there is one, two, and three debris clusters in the pipeline. lL12, 13, 14 are dust chutes, 19.20,
2L22 is a discharge valve, 23 is a pipeline, 24 is a separator, 25 is a bag filter, 126 is a pressure gauge, 27 is an air source, 28 (is a deodorizer, and 29 is a comparison calculation device).

Claims (1)

[Claims] 1. A pressure detector detects the total pressure loss in the pipeline while transporting the waste mass, and detects the amount of pressure loss generated by the next waste mass to be supplied into the pipeline from the multiple dust chutes provided in the pipeline. The pressure loss within the pipeline due to the entire waste collection is calculated by summing the estimated pressure loss value and the detected total pressure loss value, and the calculated pressure loss is less than a predetermined value. When the pressure drop is smaller than the predetermined value, the discharge valve of the dust chute scheduled to be supplied next is opened to supply the next group of dust into the pipeline, and when the calculated pressure loss is larger than a predetermined value, the discharge valve is kept closed. Pressure in a municipal waste pneumatic transportation system characterized in that the time interval of waste mass supply is extended, and when the pressure loss becomes smaller than a predetermined value, the discharge valve is opened and the next waste mass is supplied into the pipeline. Detection control method.