JPH1133432A - Hopper heater controller for eletrostatic precipitator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hopper heater controller for eelctrostatic precipitator capable of controlling the temps. of plural hoppers independently without increasing its cost. SOLUTION: Heaters 4-1 to 4-3 are attached to the respective hoppers 6-1 to 6-3 of an electrostatic precipitator 7, and the temps. of the hoppers 6-1 to 6-3 are controlled by the heaters 4-1 to 4-3. In this hopper heater controller of the electrostatic precipitator, the contacts 7-1 to 7-3 of the respective thermostats 5-1 to 5-3 set on the hoppers 6-1 to 6-3 are directly interconnected to a power source circuit to the heaters 4-1 to 4-3 attached to the hoppers 6-1 to 6-3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hopper heater control device for an electrostatic precipitator.

[0002]

2. Description of the Related Art Generally, when an electric dust collector is used, it is necessary to heat a hopper for storing dust and the like. When a plurality of hoppers are provided in one electric precipitator, conventionally, as shown in FIG.
6 and the main circuit MCCB.
(Molded Case Circuit Braker) 12, Contactor 1
3. By operating the control panel 11 having the control circuit 18 and the like, power is supplied to each heater 14 from one power source (one feeder), not shown, and each hopper 16
Is heating.

At this time, on / off of power supply to each heater 14 is controlled mainly by turning on / off the contactor 13. For example, each hopper 16 is provided with a thermostat 15 for preventing overheating. When any one of the hoppers 16 reaches a set temperature, the control circuit 18 receives a signal from the corresponding thermostat 15.
As a result, the contactor 13 is turned off, and the power supply to each heater 14 is cut off.

FIG. 3 shows an example of a control block for performing such control. In this example, the OR of the ON terminal signals of the thermostats 15 is obtained by the OR gate 20, and the result is inverted by the NOT gate 23 before being input to the AND gate 22. On the other hand, the main circuit MCC
A signal obtained by inverting the ON terminal signal of B12, a signal obtained by inverting the TRIP terminal signal of the main circuit MCCB12 by the NOT gate 24, a signal obtained by inverting the OFF terminal signal of the predetermined push button switch (PB) 19 by the NOT gate 25, and OR Gate 2
The AND gate 21 obtains the logical product of the output signal 7 (the logical sum of the ON terminal signal of another PB 19 and the output signal of the AND gate 21), and inputs the output signal to the AND gate 22. Then, the output signal of the AND gate 22 is directly input to the ON terminal of the contactor 13, and
The ON / OFF of the contactor 13 is controlled by inputting to the OFF terminal after being inverted by the T gate 26.

[0005]

In a conventional hopper heater control device, when one of a plurality of hoppers reaches a set temperature, the contactors are turned off regardless of the temperatures of the other hoppers, and all the heaters are turned off. Therefore, there is a problem that the temperature of each hopper cannot be controlled independently because power supply to the hopper is cut off.

As a countermeasure, a power supply and a contactor are provided for each heater to control the power supply to each heater and to independently control the temperature of each hopper. Cable must be added to perform the operation, thereby increasing the cost. In particular, in the case of a large-sized electric precipitator, the number of hoppers may be ten or more, and the rate of cost increase also increases.

[0007] The present invention has been made to solve such a problem, and without increasing the cost.
An object of the present invention is to provide a hopper heater control device of an electric dust collecting device capable of independently controlling the temperatures of a plurality of hoppers.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention relates to a hopper heater control device for an electric dust collector, in which a heater is attached to each hopper of the electric dust collector and the temperature of each hopper is controlled by the heater. The power supply circuit for the heaters mounted on each hopper is directly interposed with the contacts of each thermostat installed on each hopper, so that the temperature of each hopper can be controlled independently.

[0009]

FIG. 1 is a diagram showing an electric precipitator according to an embodiment of the present invention. FIG. 1 shows an electric precipitator 7 and a control panel 1 thereof, and only a portion related to hopper heater control is shown.

The electric dust collector 7 has three hoppers 6-6.
1 to 6-3 are provided. Hoppers 6-1 to 6-3
Are for storing collected fine particles such as dust, and heaters 4-1 to 4-3 for heating are provided one by one.
Is attached.

The heaters 4-1 to 4-3 are operated by electric power supplied from one heater power supply (not shown), and contact points 7 of the thermostats 5-1 to 5-3.
-1- 7-3, Main circuit MCCB (Molded Cas
e Circuit Braker) 2 and a contactor 3 are connected to a heater power supply. In this case, turning on / off the contactor 3 of the control panel 1 controls on / off of the entire heaters 4-1 to 4-3. Further, as will be described later, on / off of each of the heaters 4-1 to 4-3 is independently controlled by the contacts 7-1 to 7-3 of the thermostats 5-1 to 5-3.

The thermostats 5-1 to 5-3 prevent the hoppers 6-1 to 6-3 from being overheated by the heaters 4-1 to 4-3. Each heater 4-
1-4-3 are respectively installed at predetermined positions of the hoppers 6-1 to 6-3, and the respective contacts 7-1 to 7-3 are connected to heaters 4-1 to -7 via a control panel 1 from a heater power supply. The power supply line to 4-3, that is, the power supply circuit of the heaters 4-1 to 4-3 is directly interposed. Here, each thermostat 5-
The set temperatures 1 to 5-3, that is, the temperatures at which the contacts 7-1 to 7-3 are turned off, can be set to different values for each of the thermostats 5-1 to 5-3.

When the thermostats 5-1 to 5-3 are, for example, a heater power supply of 400V class, it is desirable to use a contact capacity of the contacts 7-1 to 7-3 of about 480V class. .

Here, when using the electrostatic precipitator 7, the thermostats 5-1 to 5-3 are turned on, and the control panel 1 is operated to switch the contactor 3 on. From heater power supply to heater 4-1
To the heaters 4-1 to 4-3.
-3 heats the poppers 6-1 to 6-3, respectively.

At this time, if any one of the hoppers 6-1 to 6-3 exceeds the set temperature of the thermostats 5-1 to 5-3, the contacts 7-1 to 7-7 of the thermostats 5-1 to 5-3. -3 are turned off, and heaters 4-1 to 4 corresponding to overheated hoppers 6-1 to 6-3
Only the power supply to -3 is cut off. At this time, if the set temperature of each of the thermostats 5-1 to 5-3 is changed, the hoppers 6-1 to 6-3 can be kept at different temperatures, and the hoppers 6-1 to 6-3 can be maintained at different temperatures. Temperature control is performed.

As described above, in the electric precipitator 7 of this embodiment, the contacts 7-1 to 7-3 of the thermostats 5-1 to 5-3 are directly interposed in the power supply circuit of the heaters 4-1 to 4-3. When any one of the hoppers 6-1 to 6-3 exceeds the set temperature of the thermostats 5-1 to 5-3, the contacts 7-1 to 7-3 of the thermostats 5-1 to 5-3. Heaters 4-1 to 4-
Hopper 6-1 because only the power supply to the hopper 3 is cut off.
Temperature control can be performed every 6-3.

In addition, it is only necessary to directly interpose the contacts of the thermostats 5-1 to 5-3 on the power supply lines of the heaters 4-1 to 4-3, and the number of parts of the entire apparatus does not increase.
There is no risk of increasing costs.

[0018]

As described above, according to the present invention, the power supply circuit for the heaters mounted on each hopper is directly interposed with the contacts of the thermostats installed on the hoppers, so that the heaters are connected to the heaters. Can be individually switched, so that the temperature of each hopper can be controlled independently. In addition, it is only necessary to directly interpose a thermostat contact in the power supply circuit to the heater, and the number of parts of the entire apparatus does not change, so that there is no possibility of increasing the cost.

[Brief description of the drawings]

FIG. 1 is a diagram showing an electric precipitator according to an embodiment of the present invention.

FIG. 2 is a diagram for explaining a conventional hopper heater control device.

FIG. 3 is a diagram showing an example of a control block of a conventional hopper heater control device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Control panel 2 ... Main circuit MCCB 3 ... Contactor 4-1 to 4-3 ... Heater 5-1 to 5-3 ... Thermostat 6-1 to 6-3 ... Hopper 7-1 to 7-3 ... Contact

Claims (1)

[Claims] A hopper heater control device for an electric dust collector, wherein a heater is attached to each hopper of the electric dust collector and the temperature of each hopper is controlled by the heater. A power supply circuit for a heater attached to each hopper. A hopper heater control device for an electric dust collecting device, wherein a contact point of each thermostat installed in each hopper is directly interposed so that the temperature of each hopper can be controlled independently.