Intelligent weighing type flowmeter and measuring control method

Abstract

The invention provides a flow controller with high precision of detection control, which can be applied to strong corrosion liquid. Two methods of weighing and weightlessness are adopted for detecting flow. A method that a stepping motor operator is used for controlling flow is adopted by output to realize continuous and stable control of liquid flow while no ripple component is available in the flow. A weightlessness self-correcting algorithm is utilized for monitoring curve correction, thereby being capable of realizing that the accumulative error of the flow approaches zero. The flow controller consists essentially of a buffer barrel, a weighing barrel, a liquid feeding electromagnetic valve and a liquid drain electromagnetic valve, a weighing display, an intelligent controller and a stepping motor operator valve. Level of the weighing barrel rises through that the buffer barrel drains liquid. When the level of the weighing barrel increases, the flow at the outlet of the motor operator valve increases and the stepping motor operator valve is gradually closed. When the level of the weighing barrel decreases, the valve is gradually opened for maintaining the flow unchanged. The process is repeated again and again. The closing speed and the opening speed of the stepping motor operator valve are exactly equal to the square roots of the rise speed and the decrease speed of liquid weight of the weighing barrel, thereby controlling the flow to be a stable straight line.

Description

(1) Technical field: [0001] This patent belongs to high-precision and continuous liquid flow detection and control technology. (two) background technology: [0002] When the mixed material enters the reactor, mixing tank and other equipment, it is necessary to perform high-precision flow detection and control of the liquid to control the product quality. At present, there are mass flowmeters, ultrasonic flowmeters, and electromagnetic flowmeters for high-precision liquid flow detection, but they are expensive, have large errors in micro-flow detection, and have no flow control. The flow detection error of the loss-in-weight flowmeter is small, but the output control must cooperate with the injection pump (metering pump). The flow output has pulsating components, and the failure to form a continuous and stable flow control has an impact on occasions that require strict uniformity such as mixing. The second is that the measurement of the flow rate is lost during the filling o...

AI Technical Summary

Problems solved by technology

In this method, the overall weight of the storage tank and the storage liquid is large. Due to the limited resolution of the load cell and the measurement system, the feeding error is large when used in small flow situations, and the measurement and control is in a blind area when the storage tank is filled with liquid.

Images