JPS595198Y2 - Cyclic plant - Google Patents

Description

[Detailed description of the invention] The present invention is applicable to combinations of blowers, pumps, compressors, etc. whose discharge sides are periodically opened and closed in accordance with the operating cycle of the plant, such as air blowers for cyclic gasification plants. This invention relates to a surging prevention device for things.

Conventionally, so-called cyclic plants (hereinafter referred to as cyclic plants), for example, operate a blower periodically.
When applied to the plant, opening and closing the plant valve installed in the air line from the blower to the cyclic plant will cause
In either state during opening or closing, the total discharge flow rate falls within the surging flow rate range, causing various troubles.

From this point of view, the present invention branches the air blowing line leading to the cyclic plant to control the operating cycle of the cyclic plant (
A pattern relief line that opens and closes in synchronization with the plant valve is provided, and a regulating valve that adjusts the discharge flow rate is installed in this pattern relief line, and a regulating valve that adjusts the discharge flow rate is installed downstream of this regulating valve in conjunction with the plant valve. A surging prevention control valve that changes the discharge flow rate of the plant valve is installed, and a control device is provided to operate the surging prevention control valve stepwise in a direction opposite to the opening/closing direction of the plant valve, thereby solving the above-mentioned drawbacks of the conventional method. When the plant valve closes, the surging prevention control valve opens in stages, and conversely, when the plant valve opens, the surging prevention control valve closes in stages, causing surging. This is to prevent

An embodiment of the present invention will be described below with reference to the accompanying drawings.

Figure 1 shows the entire blower system for a cyclic gasification plant (hereinafter referred to as a cyclic plant), not shown, in which 1 is a blower, 2 is a plant air line from this blower 1 to the cyclic plant, and 3 is this plant air blower. A plant valve installed in the line 2, 4 is a pattern relief line that opens and closes in synchronization with the operating cycle (pattern) of the cyclic plant branched from the upstream side of the plant valve 3 in the plant ventilation inlet 2. ,
5 is a regulating valve for adjusting the flow rate inside the pattern relief line installed in the pattern relief line 4;
' is this regulating valve operator.

6 is a surging prevention control valve installed in the pattern relief line 4 and downstream of the control valve 5; 7 is a surging prevention control valve 6 that is closed in stages when the plant valve 3 is open; A control device is used to control the control valve 6 so that the plant valve 3 is opened in stages when it is closed, and 8 is a surging device that receives the opening/closing signal of the plant valve 3 and sends a signal to the control device. This is a prevention circuit.

Note that when the surging prevention control valve 6 is opened and closed in stages by the control device 7, as shown in FIG. On the other hand, when closing, as shown in FIG. 2 (2), the speed is high until a certain time, and after a certain time, it is closed at a low speed.

Further, the characteristics when the plant valve 3 is in the closing direction are as shown in FIG.

Therefore, when trying to close the plant valve 3, if the surging prevention control valve 6 is operated in the opening direction with the characteristics shown in FIG. 2 (1), the total flow rate due to the two valves will be as shown in FIG. can be made to hardly change, so that the discharge flow rate of the blower 1 can be kept almost constant.

Next, the operation and effect of the above embodiment will be explained. In FIG. 1, when the cyclic plant is in operation, air is blown from the blower 1 through the plant air line 2.

When the plant stops from this operating state and Plan I valve 3 closes, a signal is sent from the surging prevention circuit 8 to the control device 7 in response to this closing signal, and the control device 7 first closes the surging prevention control valve 6. It opens at high speed to a certain opening degree, and then gradually opens at low speed until it is fully open.

As a result, as shown in Fig. 3, the total flow rate caused by the plant valve 3 and the surging prevention control valve 6 hardly changes, and therefore the discharge flow rate of the blower 1 remains almost constant, and this discharge flow rate falls within the surging flow rate range. never reach it.

In other words, the surging prevention control valve 6 is opened and closed in stages to determine its flow rate characteristics as shown in Figures 2 (1) and (2).
As a result, the total flow rate of the two valves (plant valve 3, control valve 6) is made approximately constant.

Therefore, according to the present invention, since the discharge flow rate of the blower 1 is also substantially constant, there is an effect that surging does not occur due to opening and closing of the plant valve 3.

Although the present invention has been explained in terms of a blower device for convenience, it can also be applied to surging prevention in other plants that use pumps, compressors, etc., and even if it is implemented in these, it is within the scope of the present invention. .

[Brief explanation of the drawing]

Figure 1 is a system diagram of a blower system for a cyclic plant in which the present invention is implemented, Figure 2 is a flow characteristic diagram of a surging prevention control valve, and Figure 3 is an explanatory diagram showing changes in total flow rate due to the implementation of the present invention. be. 1...Blower, 2...Plant ventilation line, 3...Plant valve, 4...Pattern relief line, 5...Adjustment valve , 6...
・Surging prevention control valve, 7...control device,
8... Surging prevention circuit.

Claims (1)

[Scope of utility model registration request] A plant ventilation line leading from the blower to the plant, a plant valve for opening and closing the plant ventilation line installed in the plant ventilation line, and a pattern in which the plant ventilation line is branched on the upstream side of the plant valve. a relief line; a control valve installed in the pattern relief line to adjust the discharge flow rate discharged through the pattern relief line; and a control valve installed downstream of the control valve in the pattern relief line and interlocked with the plant valve. a surging prevention control valve that suppresses changes in the discharge flow rate of the pattern relief line when the pattern relief line is opened and closed; and a control device that opens and closes the surging prevention control valve in a stepwise operation in a direction opposite to the opening and closing direction of the plant valve. A surging prevention device for a cyclic plant characterized by comprising: