JPH0511486B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a dust collector used to collect dust from a duct generated from a plurality of dust sources such as a coal storage tank and a blending tank.

(Prior art) In a dust collector in which branch ducts with end dampers are arranged for multiple dust sources,
Normally, the main damper of the exhaust fan is kept fully open, and each end damper is opened or closed depending on the state of dust generation. However, this method only increases the pressure loss within the duct system and has the drawback that the load on the exhaust fan drive motor is always kept at a maximum. Therefore, as shown in Japanese Unexamined Patent Publication No. 55-94616, the main damper of the exhaust fan is opened and closed depending on how many end dampers among the n branch ducts are opened, and thereby the necessary It has been proposed to reduce the load on the drive motor according to changes in the amount of dust air. However, in this conventional method, the opening degree of the main damper is controlled in accordance with the number of end dampers that are opened, so if the air volume of each branch duct is uniform, favorable control can be achieved. There was a problem that accurate control could not be performed when the air volume differed.

(Problems to be Solved by the Invention) The present invention solves the conventional problems as described above, and when the air volume of each branch duct is different, the entire system can be operated under optimal conditions. Moreover, it was completed with the aim of creating a dust collector that can reduce the load on the drive motor of the exhaust fan in accordance with the required total dust collection air volume.

(Means for Solving the Problems) The present invention is a dust collector in which a plurality of branch ducts facing a plurality of dust sources and each opened and closed by an individual end damper are connected to an exhaust fan via a main duct. A limit switch is installed on each end damper to detect its opening/closing, and the required total dust collection air volume is calculated based on the on/off signal of each limit switch on the exhaust fan.Based on this, the pressure loss between the dust collector and the duct system is calculated. Furthermore, the present invention is characterized in that an arithmetic unit that calculates the number of rotations of the exhaust fan based on this and an inverter controller that controls the number of rotations according to the output of this arithmetic unit are connected.

(Embodiment) Next, the present invention will be described in detail with reference to the illustrated embodiment. In FIG.
Branch ducts are opened and closed by a to 3e, 4 is a main duct, 5 is a dust collector, 6 is a main damper of the main duct 4, and 7 is an exhaust fan. Each end damper 3a-3
Limit switches 8a to 8e are attached to e to detect the opening and closing thereof, and the output of each limit switch 8a to 8e is input to a computing unit 9.

The arithmetic unit 9 is, for example, a program controller, and has the function of performing three stages of arithmetic operations as shown in FIG. As a first step,
The limit switches 8a to 8e receive on/off signals indicating which end damper 3 of each branch duct 2a to 2e is open and which end damper 3 is closed. The computing unit 9 stores a unique air volume value for each end damper 3,
The computing unit 9 calculates the required total dust collection air volume by adding up the characteristic air volume values of the branch ducts 2 in which the end dampers 3 are opened. As a second step, the calculator 9 calculates the overall pressure loss based on the calculated required total dust collection air volume. The pressure loss is composed of the resistance of the duct system and the resistance of the dust collector 5, and the resistance of the duct system is proportional to the square of the air volume, and the resistance of the dust collector 5, such as a bag filter, is a linear function of the air volume. After calculating the pressure loss based on these calculation formulas, in the third step, the rotation speed of the exhaust fan 7 is calculated based on the required total dust collection air volume and the pressure loss. The rotation speed is determined so as to ensure the required total dust collection air volume and to obtain the required static pressure.

Reference numeral 10 denotes an inverter controller connected to the exhaust fan 7, and when the computing unit 9 determines the rotation speed of the exhaust fan 7 as described above, the rotation speed of the drive motor of the exhaust fan 7 is controlled accordingly.

(Function) The device configured in this way has multiple dust sources 1
Among the branch ducts 2a to 2e facing a to 1e,
It is the same as before that only the end dampers of the necessary branch ducts are opened to suck in the dust-containing gas, and the dust-containing gas is collected in the main duct 4 and then collected by the dust collector 5. . However, in the present invention, the end damper of which branch duct is opened is detected by the limit switch 8 attached to each end damper, and the calculator 9 adds up the characteristic air volume values in accordance with the on/off signals of each limit switch 8a to 8e. The required total dust collection air volume is calculated, and the pressure loss and the rotation speed of the exhaust fan 7 are calculated below based on this required total dust collection air volume. The control system can be simplified compared to the control system, and the exhaust fan 7 can always be operated under optimal conditions even when the air volume values differ greatly for each end damper 3a to 3e.
can drive. In addition, in the present invention, the inverter controller 10 controls the drive motor of the exhaust fan 7 according to the calculation result of the calculator 9 to control the rotation speed to an optimal value taking into consideration the air volume and pressure loss. It is possible to accurately reduce the load on the drive motor in accordance with the load.

(Effects of the Invention) As is clear from the above description, the present invention allows the entire system to be operated under optimal conditions without unnecessarily increasing the number of control stages even when the air volumes of the branch ducts differ individually. At the same time, the power of the exhaust fan can be reduced in accordance with the required total dust collection air volume. Therefore, the present invention greatly contributes to the development of industry as a dust collector that solves the conventional problems.

[Brief explanation of drawings]

FIG. 1 is a piping system diagram showing an embodiment of the present invention, and FIG. 2 is a block diagram of a control system. 1: Dust source, 2: Branch duct, 3: Terminal damper, 4: Main duct, 5: Dust collector, 7: Exhaust fan,
8: Limit switch, 9: Arithmetic unit, 10: Inverter controller.

Claims (1)

[Claims] 1 A dust collection device in which a plurality of branch ducts 2 facing a plurality of dust sources 1 and opened and closed by individual end dampers 3 are connected to an exhaust fan 7 via a main duct 4, and each end damper 3 has a A limit switch 8 is installed to detect the opening/closing of the exhaust fan 7.
The required total dust collection air volume is calculated based on the on/off signal of each limit switch 8, and based on this, the dust collector 5
A calculator 9 that calculates the pressure loss between the air blower and the duct system, and further calculates the rotation speed of the exhaust fan 7 based on this, and an inverter controller 10 that controls the rotation speed according to the output of the calculator 9. A dust collector characterized by being connected.