JPS6010565B2 - Flow rate diversion measurement control device using a critical flow nozzle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a flow rate diversion measurement control device using a critical flow nozzle.

Traditionally, there have been devices for collecting samples proportional to the flow rate or measuring the total flow rate in channels where the flow rate changes, but these devices are too expensive due to their complex structures, and the measurement accuracy is limited. There are also problems in this respect, and users are not necessarily satisfied.

The present invention was made in view of this, and its purpose is to provide a flow rate diversion measurement control device using a critical flow nozzle that is extremely simple and has high measurement accuracy. In addition to being able to collect samples proportional to the flow rate and measuring the total flow rate during changing flow rates, it can also be applied to various exhaust gases and large-capacity flow path systems.

Hereinafter, the present invention will be explained based on embodiments shown in the drawings.

A column 3 is fixed at right angles to the direction of flow of the fluid 1 in a pipe 2 of uniform thickness through which a fluid 1 having a substantially uniform flow velocity distribution flows. A branch pipe 4 having a small diameter and a constant length is provided extending from the upstream side to the downstream side in the direction of the flow of the fluid 1, and the flow is located at a position in the pipe line 2 that provides a typical flow rate condition. shall be. The above-mentioned branch pipe 4 is provided with a pipe name with the same conditions as "Multiple branch pipes".

The branch pipe 6 is arranged parallel to the branch pipe 4 and similarly penetrates the column 3, and its downstream part is separated from the pipe case 2 by the conduit 6, and its tip is a sonic nozzle with a variable area. 7, further connected to a pump 8, and finally connected to a discharge pipe 9. Inside the branch pipes 4 and 5, there is a relatively responsive current meter, for example, a hot pig anemometer 10.
and 1 1 are provided, and the fluid 1 passing through the branch pipes 4 and 5
They are each connected to a comparison device 12 so that the average value of the speed of each vehicle can be detected and compared under substantially the same conditions.

The comparator 12 is further connected to a servo device 3 that controls the area of the throw section of the variable area sonic nozzle 7;
Further, a flow rate measuring device 4 is connected between the sonic nozzle 7 and the servo device blade 3.

The absolute value of the flow rate of the branch pipe 5 can be measured and controlled based on the area of the throw section of the variable area sonic nozzle 7, the pressure P and the temperature T at the upstream section thereof.

As described above, the present invention has the following features: ``When the fluid 1 in the pipe line 2 flows from before the column 3 to the branch pipes 4 and 5, the inside of the branch pipes turtle and 6 has a relatively responsive hot wire wind velocity. A servo device that operates according to the output of comparison device 2 is used to detect and compare the average values of the respective flow velocities under the same conditions. The area of the throat part of the sonic nozzle 7 with a variable area is controlled by the turtle 31, and as a result, the
The flow rate can always be the same as that of the branch pipe 4 or at a constant ratio.

In this way, the accurate flow rate of the flow branch pipe 5 can be recorded by the measuring device Tomikawa. In addition, the downstream of the branch pipe 5 passes through a conduit and flows into a sonic nozzle 7, which is then sucked in by a pump 8 and sampled through a discharge pipe 9, or discharged. Any of these can be selected arbitrarily.The present invention is characterized in that by controlling and measuring the flow rate of the branch pipe 5 as described above, the flow rate of the entire pipe line 2 can be measured, and at the same time, the flow rate of the sample proportional to the flow rate can be measured. It is possible to collect samples by isokinetic suction within the conduit 2, and it is an extremely simple device that has excellent effects such as being able to improve measurement accuracy.

[Brief explanation of the drawing]

The figure shows an embodiment of a flow rate diversion measurement and control device using a critical flow nozzle according to the present invention. Tortoise...Fluid" 2...Pipe line t Tortoise...Diversion pipe" 6...Diversion pipe,
y...Sonic speed nozzle with variable area.

Claims (1)

[Claims] 1. A channel through which a fluid with a substantially uniform flow velocity distribution flows, and a plurality of predetermined units arranged within this channel that maintain a constant flow rate with respect to the total flow rate flowing through the channel with the same inlet conditions. a sonic velocity nozzle with a variable throat area connected to one of the branched channels and connected to a conduit led out of the flow channel; and a sonic nozzle connected to the downstream side of the sonic nozzle. a pump that leads out of the flow path, a flow meter provided inside one of the flow paths in the flow path, a comparison device that compares the measured values of these flow speed meters, and the comparison device a servo device that is activated based on the comparison result and controls the throat area of the sonic nozzle so that it is equal to or a constant ratio of the flow rate in the branch flow path having the current meter; pressure,
and a flow rate measuring device that measures the flow rate based on temperature, so that it is possible to measure the divided flow rate and the total flow rate before dividing while sampling a sample proportional to the total flow rate of the flow path through the sonic nozzle. A flow rate diversion measurement control device using a critical flow nozzle.