CN108444555A - A kind of novel Venturi tube-type spreader flowmeter - Google Patents

Abstract

The invention discloses a novel Venturi tube type flowmeter, which consists of a Venturi tube body and a Venturi tube throat. The outlet rectangular channel section, the inlet rectangular channel section is provided with the first pressure measuring hole, the middle section is provided with the first pressure measuring channel, the venturi tube throat and the middle section of the Venturi tube body are installed together by interference fit , the throat of the Venturi tube is provided with a second pressure measurement channel, which vertically overlaps with the first pressure measurement channel, thereby forming a second pressure measurement hole. Compared with the general traditional Venturi tube flowmeter, the Venturi tube flowmeter disclosed by the present invention has stronger applicability, not only can accurately measure different flow rates, but also reduces manufacturing and use costs, and the economic benefits are very considerable .

Description

A New Venturi Tube Flowmeter

technical field

The invention belongs to the field of flow measurement, and relates to a flow measurement device, in particular to a novel Venturi tube flowmeter.

Background technique

Differential pressure flowmeter, as a traditional measurement method, has a history of nearly a hundred years, and it is still the most widely used industrial on-line flow measurement instrument today.

According to the structure, the Venturi tube is divided into a built-in Venturi tube and an inserted Venturi tube. Good results have been obtained in the measurement of combustion-supporting air, cold air, and gas (blast furnace gas, coke oven gas, converter gas) of hot blast stoves in iron and steel plants, and the measurement of primary air and secondary air of boilers in thermal power plants with large diameter and low flow velocity. It solves the problem of accurate measurement of various gas flows at medium and low pressures, large pipe diameters, and low flow rates in current industrial enterprises. Fluid measuring device with wide measuring range and easy installation. The unique structural design and data processing method have strict fluid mechanics basis, and the actual flow calibration is carried out in the national large-scale key wind tunnel laboratory.

When the fluid filled with the Venturi flowmeter pipe flows through the throttling piece in the Venturi flowmeter pipe, the flow velocity will form a local contraction at the Venturi flowmeter throttling piece, so the flow velocity increases and the static pressure decreases, so in A pressure differential is created before and after the throttle of the Venturi flowmeter. The greater the fluid flow rate, the greater the pressure difference generated, so the flow rate can be measured according to the pressure difference. This measurement method is based on the flow continuity equation (law of conservation of mass) and the Bernoulli equation (law of conservation of energy).

Contents of the invention

The purpose of the present invention is to provide an improved differential pressure type venturi tube flowmeter, which is more versatile than the ordinary venturi tube flowmeter, and realizes the control by only changing the design size of the venturi tube throat. Accurate measurement of different flow intake ranges without replacing the entire Venturi tube, thereby reducing manufacturing and maintenance costs and improving economic efficiency.

Technical scheme of the present invention is:

A novel Venturi tube type flowmeter, which consists of a Venturi tube body and a Venturi tube throat, is characterized in that the middle section of the Venturi tube body and the Venturi tube throat are positioned by a rectangular second measurement Press holes, and interference fit.

Further, the Venturi tube body is a Venturi-shaped rectangular channel opened axially at one end of the cylindrical entity, which sequentially includes an inlet rectangular channel section, a decompression section, a middle section, a pressurization section and an outlet rectangular channel section, On the inlet rectangular channel section, a first pressure measuring hole is provided at a position that is one-third of the length of the entire inlet rectangular channel from the inlet end face, and a first pressure measuring channel is provided at the middle part of the middle section.

Further, the throat of the Venturi tube is provided with a positioning section, a second pressure measuring channel and an end slope section, the positioning section is positioned and connected with the decompression section of the Venturi tube body and the slot at the junction of the middle section, and the second pressure measuring The channel is concentric with the first pressure measurement channel provided in the middle section of the Venturi tube body, and has the same diameter as the first pressure measurement channel. The combination of the first pressure measurement channel and the second pressure measurement channel forms the second pressure measurement hole, and the slope section at the end Cooperate with the same slope as the supercharging section of the Venturi tube body.

The beneficial effects of the present invention are:

1. Compared with the ordinary Venturi tube flowmeter, the biggest difference of the new Venturi tube flowmeter of the present invention is that it adopts a split design, which can be realized by only changing the design size of the Venturi tube throat. Accurate measurement of flow intake range without replacing the entire Venturi tube, which greatly saves manufacturing and use costs;

2. The present invention adopts a built-in venturi tube in a rectangular pipeline. Compared with a built-in venturi tube in a circular pipeline, it has a large differential pressure, high precision, and a wide measurement range. clogging phenomenon.

Description of drawings

Accompanying drawing 1, the structural representation of the novel Venturi tube flowmeter of the present invention.

Accompanying drawing 2 is the schematic cross-sectional structure diagram of the Venturi tube body of the novel Venturi tube flowmeter of the present invention.

Accompanying drawing 3, the structure diagram of venturi tube throat of the novel venturi tube type flowmeter of the present invention.

Accompanying drawing 4, the sectional structure schematic diagram of venturi tube throat of the novel venturi tube type flowmeter of the present invention.

In the figure: 1. Inlet rectangular channel section, 2. First pressure measuring hole, 3. Decompression section, 4. Second pressure measuring hole, 5. Middle section of Venturi tube body, 6. Throat of Venturi tube, 7 , Venturi tube body, 8, booster section, 9, outlet rectangular channel section, 10, first pressure measurement channel, 11, second pressure measurement channel, 12, throat entrance positioning section, 13, throat end slope section .

Detailed ways

The specific structure and implementation mode of the present invention will be further described below in conjunction with the accompanying drawings.

Referring to Figures 1 to 4, the structural composition of the venturi flowmeter with a built-in rectangular pipe and split type of the present invention includes a venturi body (7) and a venturi throat (6). The middle section (5) of the Venturi tube body and the throat (6) of the Venturi tube locate the second pressure measuring hole (4) through a rectangle, and are interference fit.

The Venturi tube body (7) is a venturi-shaped rectangular channel opened axially at one end of a cylindrical entity, including an inlet rectangular channel section (1), a first pressure measuring hole (2), a decompression section (3 ), the middle section of the Venturi tube body (5), the booster section (8), the outlet rectangular channel section (9), and the first pressure measuring channel (10); on the inlet rectangular channel section (1), the distance from the inlet end face is A first pressure measuring hole (2) is provided at one-third of the entire entrance rectangular channel; and a first pressure measuring channel (10) is provided at the middle part of the middle section (5).

The throat of the Venturi tube (6) is provided with a throat inlet positioning section (12), a second pressure measuring channel (11) and a slope section (13) at the end of the throat, and the throat inlet positioning section (12) is connected to the venturi The connection between the decompression section (3) and the middle section (5) of the inner pipe body is fixed and connected with the card groove, and the second pressure measurement channel (11) is connected with the first pressure measurement channel ( 10) Concentric and the same diameter as the first pressure measurement channel (10), the combination of the first pressure measurement channel (10) and the second pressure measurement channel (11) forms the second pressure measurement hole (4), the slope section at the end of the throat (13) Cooperate with the supercharging section (8) of the Venturi tube body on the same slope.

Working process of the present invention is as follows:

The novel Venturi tube flowmeter of the present invention can meet the requirements for accurate measurement of different intake flow ranges by changing the design size of the throat. When it flows into the throttling part of the Venturi flowmeter pipeline, that is, the decompression section (3), due to local contraction, the flow rate increases and the static pressure decreases, so the inlet rectangular channel (1) is before and after the throttling part of the Venturi flowmeter. There is a pressure difference between the pressure reducing section (3); because the first pressure measuring hole (2) and the second pressure measuring hole (4) are respectively connected to the inlet rectangular hole (1) and the throat of the Venturi tube (6) are connected, so we can measure the respective specific pressure values at the first pressure measuring hole (2) and the second pressure measuring hole (4), so as to obtain the inlet rectangular channel (1) and the decompression section (3) pressure difference between them. The greater the fluid flow rate, the greater the pressure difference generated, so the flow rate can be measured according to the pressure difference. And because the size of the Venturi tube throat (6) determines the accuracy and range of the measured flow rate, when the current Venturi tube flowmeter can no longer meet the accurate measurement of the current changing flow rate, we can choose to replace it with a different size. Venturi tube throat (6) to meet the requirements without replacing the entire Venturi tube, so as to reduce production costs and improve economic benefits.

The basic principles and main features of the present invention have been shown and described above. The present invention is not limited by the above-mentioned embodiments, and the above-mentioned embodiments and instructions describe only the principles of the invention. Without departing from the spirit and scope of the present invention, the present invention also has various changes and improvements. These inventions and improvements All belong to the scope of the claimed invention.

Claims (3)

1. a kind of novel Venturi tube-type spreader flowmeter, composition includes Venturi tube ontology and venturi throat, feature It is：The interlude of the Venturi tube ontology positions the second pressure tap with venturi throat by rectangle, and interference is matched It closes.

2. a kind of novel Venturi tube-type spreader flowmeter according to claim 1, it is characterised in that：Venturi tube ontology is In the Venturi tube-type spreader rectangle duct that cylindrical solid one end opens up in an axial direction, successively include entrance rectangle duct section, decompression section, in Between section, boost section and outlet rectangle duct section be entire entrance rectangle duct away from entrance face in the section of entrance rectangle duct At one third, equipped with the first pressure tap, position is equipped with the first measuring pressure passage therebetween on interlude.

3. a kind of novel Venturi tube-type spreader flowmeter according to claim 1, it is characterised in that：The Venturi tube Throat is equipped with positioning section, the second measuring pressure passage and end gradient section, and positioning section connects with Venturi tube ontology decompression section and interlude The place's of connecing card slot is located by connecting, and the second measuring pressure passage and the first measuring pressure passage that Venturi tube ontology interlude is equipped with are concentric, and Identical as the first measuring pressure passage diameter, the first measuring pressure passage and the second measuring pressure passage combine to form the second pressure tap, the end gradient Section coordinates with Venturi tube ontology boost section with the gradient.