JPS593313A - Incinerator exhaust gas flow rate measurement device - Google Patents

Abstract

PURPOSE:To make an inspection and a maintenance unnecessary by converting a detected amount of a detecting means of a current loaded to a driving motor for a waste gas drawing blower to a waste gas flow rate, basing on the waste gas flow rate - the load current characteristics of the motor obtained previously. CONSTITUTION:The load current characteristics of the waste gas flow rate motor 3 obtained based on an opening degree of an entrance damper 2 of the drawing blower 1, a static pressure characteristics of th blower 1 and the load current characteristics of the motor 3 are stored. The detected value (load current IM) of a current converter 4 is converted into the waste gas flow rate basing on the load current characteristics. The load current IM of the motor 3 is supplied to the first or second converter 7, 8 through a comparison arithmetic device 5, a changeover device 6. There, the current is converted into the waste gas flow rate and is inputted to a suitable display recording means, etc. through an OR circuit 9.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improved measuring device for incinerator exhaust gas flow rate.

The problems with conventional exhaust gas flowmeters used in incinerators are as follows.

(1), Porous Pitot tube ■) It is not possible to obtain a uniform laminar flow section and high accuracy cannot be obtained.

2) The measurement hole is blocked by dust that is mixed in the exhaust gas (regular maintenance required).

3) It is expensive to take anti-corrosion measures (all made of SUS).

(2) Turbine meter (blade wheel type anemometer) 1) A uniform laminar flow section cannot be obtained and high accuracy cannot be obtained.

2) An air hose is required to prevent dust from adhering to the rotating part bearing.

3) Corrosion countermeasures are required.

A more general problem is that (1) and (2) uniform flow is necessary to guarantee high accuracy, but this cannot be maintained due to the layout of the factory (there is no space), resulting in high accuracy. decreases. The biggest problem is that the exhaust gas is corrosive, and the operation is generally performed at temperatures above the acid dew point. (for example, low temperature during wet Hel removal equipment operation and high temperature during bino-gas operation), and the locations where flowmeters can be installed are limited, making it difficult to take countermeasures against corrosion.

Therefore, the present inventor conducted research to solve the above problems, and as a result, obtained the following findings.

(1) - The exhaust gas flow rate of the incinerator is controlled by changing the opening degree of the artificial damper of the induced blower so as to maintain the pressure inside the furnace at a constant negative pressure. At this time, the air volume (exhaust gas flow rate) is
Population damper J? It is determined at the point where the blower static pressure characteristic curve corresponding to the opening degree of the system matches the system-specific pressure curve (see the upper part of Figure 1). The load current characteristics of the drive motor for the induced blower also change depending on the opening degree of the artificial damper (see the lower part of FIG. 1).

(2) From the above, it is possible to obtain the exhaust gas flow rate vs. load current characteristic when the artificial damper + changes, and the relationship can be expressed by two linear approximations using, for example, the reference load current amount (actual measurement) as the boundary. (See Figure 2) 0 This invention was made based on the above knowledge, and includes a detection means for detecting the load current of a drive motor for an incinerator exhaust gas induced blower, and an artificial damper opening degree of the blower. , storage means for storing the exhaust gas flow rate-load current characteristic of the motor obtained based on the static pressure characteristic of the blower and the load current characteristic of the motor; The present invention is characterized in that the incinerator exhaust gas flow rate measuring device includes a converting means for converting the detected value of the detecting means into an exhaust gas flow rate.

The present invention will be explained below by way of examples with reference to the drawings.

FIG. 3 is a schematic configuration diagram of the apparatus according to the present invention. In the figure, 1 is an induced fan, and 2 is an induced fan A? , 3 is a motor for driving the induced fan 1, 4 is a current converter for detecting the load current In of the motor 3, and 5 is a load current IM and a reference current Is obtained in advance.
6 is a switch, 7 and 8 are first converters for low flow rate that correspond to a lower current than the reference current Is as a boundary, and , a second converter for high flow rate, which corresponds to a current higher than the reference current Is. First and second converter 7
and 8 are exhaust gas flow rate-load current characteristics of the motor 3 (
(see FIG. 2, F, , F2),
It also includes a conversion circuit for converting the detected value (load current IN) of the current converter 4 into an exhaust gas flow rate based on the exhaust gas flow rate-load current characteristic of the motor 3. 1st
The output signal of the second converter 7.8 is input via an OR circuit 9 to a suitable display/recording means (not shown). Comparison calculator 5 calculates that load current IM is reference current 1. A switching signal causes the switch 6 to send the load current IM to the second converter 7 when the load current II is lower than the reference current TS, and to send the load current IM to the second converter 8 when the load current II is higher than the reference current TS.
control.

With the above configuration, the load current IM of the motor 3 is sent to the first or second converter 7, 8 through the comparator 5 and the switch 6, where it is converted into an exhaust gas flow rate and OR
It passes through the circuit 9 and is input to a suitable display/recording means or the like.

Note that the reference current, approximate equation coefficients, etc. for determining the exhaust gas flow rate-load current characteristic can be determined or changed depending on the blower, motor, etc., for example.

As explained above, in this invention, since the exhaust gas flow rate is not directly measured, 1) The conventional protection, inspection, and maintenance of the detection end is unnecessary.

2) Settings can be made after Zorant is in operation and are flexible.

3) High accuracy can be obtained.

4) It is inexpensive and requires no maintenance costs.

Effects such as this can be obtained.

[Brief explanation of the drawing]

Figure 1 is a diagram showing the characteristics corresponding to the exhaust gas flow rate;
The figure shows the exhaust gas flow rate vs. motor load current characteristics.
The figure is a schematic configuration diagram of an apparatus according to the present invention. 1... Induced blower 2... Artificial damper 3...
Motor 7, 8...Converter 6 Applicant: Nippon Steel Tube Co., Ltd. Agent Keitabe Tsutsumi and 1 other person

Claims (1)

[Claims] Detecting means for detecting a load current of a drive motor for an incinerator exhaust gas induced blower, an artificial damper opening degree of the blower, static pressure characteristics of the blower,
and storage means for storing the exhaust gas flow rate-load current characteristic of the motor obtained based on the load current characteristic of the motor; , exhaust gas flow rate