CN216213117U

CN216213117U - Flame-proof thermal difference type flow switch

Info

Publication number: CN216213117U
Application number: CN202122193676.5U
Authority: CN
Inventors: 黄离京; 王旭婷
Original assignee: Wuhan Huamingyuan Technology Co ltd
Current assignee: Wuhan Huamingyuan Technology Co ltd
Priority date: 2021-09-11
Filing date: 2021-09-11
Publication date: 2022-04-05
Anticipated expiration: 2031-09-11

Abstract

The utility model discloses a flame-proof thermal difference type flow switch, which comprises a base, wherein the top of the base is provided with a mirror window upper cover, and the bottom of the base is provided with a thermal difference type flow probe; the top of the upper cover of the mirror window is provided with a hollowed-out window, a transparent mirror window sheet is arranged in the upper cover of the mirror window, the transparent mirror window sheet is fixed in the upper cover of the mirror window through a mirror window pressing sheet and a mirror window pressing ring, and the transparent mirror window sheet and the upper cover of the mirror window are sealed through epoxy resin; the explosion-proof thermal difference type flow switch disclosed by the utility model can be safely used in any IIC-level explosion-proof occasions specified in national standards GB3836.1 and GB 3836.2; the protection grade IP65 can meet the requirement of normal use in the field environment; the product has compact structure, small size and delicacy, and is very convenient to install, use and maintain; no moving parts and extremely low power consumption, so the service life of the product is 3 to 5 times longer than that of the same type of products at home and abroad.

Description

Flame-proof thermal difference type flow switch

Technical Field

The utility model belongs to the technical field, and particularly relates to an explosion-proof thermal difference type flow switch.

Background

In the process industry of petroleum, petrochemical industry and the like, a potential explosive environment can occur, and corresponding explosion-proof measures must be taken on field related equipment in the system in practice. The explosion-proof technology adopted by the automatic control instrument mainly comprises the following steps: intrinsic safety (Exi), explosion suppression (Exd), increased safety (Exe), positive pressure (Exp), encapsulation (Exm) and the like. Among the explosion-proof technologies, the explosion-proof and explosion-proof technology, which is a safety technology for blocking the energy of an ignition source as an explosion-proof means, is widely used in engineering projects of various industries at present, and the explosion-proof and explosion-proof instrument puts forward new requirements on products in terms of structure and material, and there is an urgent need to design an explosion-proof thermal difference type flow switch.

SUMMERY OF THE UTILITY MODEL

The utility model provides an explosion-proof thermal difference type flow switch, aiming at solving the existing problems.

The utility model is realized in this way, a flame-proof type heat difference type flow switch, including the base frame, there are upper covers of the mirror window on the top of the said base frame, the bottom of the said base frame is fitted with the heat difference type flow probe; the top of the upper cover of the mirror window is provided with a hollowed-out window, a transparent mirror window sheet is arranged in the upper cover of the mirror window, the transparent mirror window sheet is fixed in the upper cover of the mirror window through a mirror window pressing sheet and a mirror window pressing ring, and the transparent mirror window sheet and the upper cover of the mirror window are sealed through epoxy resin; the differential flow probe of heat includes the mount pad, the mount pad bottom is provided with two U type sensors, U type sensor includes the stainless steel protective sheath of U type, install PN junction semiconductor temperature sensing element in the stainless steel protective sheath, PN junction semiconductor temperature sensing element's both ends are followed respectively stainless steel protective sheath both ends are stretched out, just PN junction semiconductor temperature sensing element with it has insulating fixed filler to fill between the stainless steel protective sheath.

Furthermore, an inner thread is formed in the inner wall of the upper cover of the mirror window, an outer thread is formed in the base body, a sealing ring is arranged between the upper cover of the mirror window and the base body and is in threaded connection with the base body, M95-1.5 threads are adopted, the number of thread buckles is larger than 8, and the thread precision is 6g 6H.

Further, a functional circuit module and a data display module are arranged on the seat body, and the data display module is over against the transparent sheet of the mirror window; the socket, the data display module and the thermal difference type flow probe are electrically connected with the functional circuit module respectively.

Further, the base body is connected with the mounting base through screws, the base body and the mounting base are sealed through epoxy resin, and the height difference between the top surface of the sealed glue and the bottom surface of the inner wall of the base body is 8-12 mm.

Further, the surface of the upper cover of the mirror window is provided with a forbidden identification area, the surface of the base body is provided with a nameplate installation area, and the side edge of the wiring socket is provided with a grounding identification.

Furthermore, the top of the mounting seat is provided with a connecting part, a cavity is formed in the mounting seat, insulating fixing fillers are filled in the cavity, and the insulating fixing fillers are temperature-resistant insulating epoxy resin.

Furthermore, a mounting hole is formed in the bottom of the mounting base, and the end of the stainless steel protective sleeve is riveted and fixed with the mounting hole.

Furthermore, one of the U-shaped sensors is a reference sensor, and the other U-shaped sensor is a self-heating sensor.

Furthermore, the surface of the upper cover of the mirror window is provided with anti-skid convex ribs.

Compared with the prior art, the utility model has the beneficial effects that: the explosion-proof thermal difference type flow switch disclosed by the utility model can be safely used in any IIC-level explosion-proof occasions specified in national standards GB3836.1 and GB 3836.2; the protection grade IP65 can meet the requirement of normal use in the field environment; the product has compact structure, small size and delicacy, and is very convenient to install, use and maintain; no moving parts and extremely low power consumption, so the service life of the product is 3 to 5 times longer than that of the same type of products at home and abroad.

Drawings

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is a front view in half section of the present invention;

FIG. 3 is a top half sectional view of the present invention;

FIG. 4 is a schematic diagram of a thermal differential flow probe according to the present invention;

FIG. 5 is a cross-sectional view of a thermally differential flow probe of the present invention;

FIG. 6 is a schematic view of a U-shaped sensor according to the present invention;

in the figure: the device comprises a 1-PN junction semiconductor thermosensitive element, a 2-stainless steel protective sleeve, a 3-insulating fixed filler, a 4-mounting seat, a 5-U-shaped sensor, a 6-base body, a 7-mirror window upper cover, an 8-thermal differential flow probe, a 9-mirror window transparent sheet, a 10-mirror window transparent sheet, an 11-mirror window pressing ring, a 12-data display module, a 13-functional circuit module, a 14-plug and a 15-wiring socket.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the utility model and are not intended to limit the utility model.

In the description of the present invention, it is to be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on the orientations or positional relationships illustrated in the drawings, and are used merely for convenience in describing the present invention and for simplicity in description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed in a particular orientation, and be operated, and thus, are not to be construed as limiting the present invention. Further, in the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

Referring to fig. 1-6, the present invention provides a technical solution: a flame-proof type thermal difference type flow switch comprises a base 6, wherein the top of the base 6 is provided with a mirror window upper cover 7, and the bottom of the base 6 is provided with a thermal difference type flow probe 8; the top of the upper cover 7 of the mirror window is provided with a hollow window, a transparent sheet 9 of the mirror window is arranged in the upper cover 7 of the mirror window, the transparent sheet 9 of the mirror window is fixed in the upper cover 7 of the mirror window through a pressing sheet 10 of the mirror window and a pressing ring 11 of the mirror window, and the transparent sheet 9 of the mirror window and the upper cover 7 of the mirror window are sealed by epoxy resin; thermal difference type flow probe 8 includes

mount pad

4, 4 bottoms of mount pad are provided with two U type sensors 5, U type sensor 5 includes the stainless steel protective sheath 2 of U type, install PN junction semiconductor thermistor 1 in the stainless steel protective sheath 2, PN junction semiconductor thermistor 1's both ends are stretched out from stainless steel protective sheath 2 both ends respectively, and it has insulating fixed filler 3 to fill between PN junction semiconductor thermistor 1 and the stainless steel

protective sheath

2, 7 surfaces on the mirror window are provided with anti-skidding stupefied.

In the embodiment, the explosion-proof shell of the flow switch has the structural strength capable of bearing the internal explosion pressure. In order to adapt to the severe environment in the field and meet the explosion-proof requirement, an aluminum alloy shell is selected. According to the material for manufacturing the shell of the class II thermal difference type flow switch, the magnesium content is not allowed to be more than 6 percent by mass percent. The transparent piece of the observation window of the upper cover of the explosion-proof shell is also a part of the explosion-proof shell and can bear the action of explosion pressure in the shell; secondly it can withstand the effects of external conditions in the environment of use: mechanical (bumping, pounding, bumping), chemical, thermal, etc. The transparent piece is made of glass material.

In order to ensure the pressure resistance of the explosion-proof shell, the shell with enough structural strength is designed under the condition of correct material selection. In designing the flow switch housing, the strength of the housing should be determined taking into account the volume of the housing. The strength of the shell can be determined by calculation based on the material and the pressure it may be subjected to. In addition, the pressure overlapping phenomenon in the shell is also considered in the design process of the flameproof shell. The housing is not adapted to be formed as a multi-cavity body with small holes communicating with each other. The mounting of the electrical components in the housing should also avoid dividing the entire cavity into several small cavities. In addition, the longitudinal and transverse dimensions of the housing should not be too large, otherwise pressure overlap within the housing may occur. The strength of the shell in which the pressure overlap phenomenon exists can be determined only after the dynamic pressure test.

This shell intensity design has considered and has reached: the class IIC thermal difference type flow switch shell can bear a 1.5MPa water pressure test and can not be damaged after 12 seconds.

Specifically, the inner wall of the upper mirror window cover 7 is provided with an internal thread, the base body 6 is provided with an external thread, a sealing ring is arranged between the upper mirror window cover 7 and the base body 6 and is in threaded connection with the internal thread, M95-1.5 threads are adopted, the number of thread buttons is greater than 8, and the thread precision is 6g 6H. The base body 6 is provided with a functional circuit module 13 and a data display module 12, and the data display module 12 is over against the transparent lens 9; a wiring socket 15 is arranged on one side of the seat body 6, a plug 14 is arranged on the other side of the seat body 6, and the wiring socket 15, the data display module 12 and the thermal difference type flow probe 8 are electrically connected with the functional circuit module 13 respectively.

The base body 6 is connected with the mounting base 4 through screws, the base body 6 and the mounting base 4 are sealed through epoxy resin, and the height difference between the top surface of the seal and the bottom surface of the inner wall of the base body 6 is 8-12 mm. The surface of the upper cover 7 of the mirror window is provided with a forbidden identification area, the surface of the base body 6 is provided with a nameplate installation area, and the side edge of the wiring socket 15 is provided with a grounding identification.

Connecting portion are provided with at 4 tops of mount pad, have seted up the cavity in the mount pad 4, and the cavity intussuseption is filled with insulating fixed filler 3, and insulating fixed filler 3 is the insulating epoxy of temperature resistant. The mounting hole has been seted up to mount pad 4 bottom, and 2 tip of stainless steel protective sheath are fixed with the mounting hole riveting. One of the U-shaped sensors 5 is a reference sensor, and the other U-shaped sensor 5 is a self-heating sensor.

In the present embodiment, the flow rate switch includes a power supply lead-in, a load output, an electric signal input/output, and the like. For this purpose, it is necessary to provide a lead-in device for the input or output.

The utility model discloses an explosion-proof thermal difference type flow switch which adopts an introducing device with a rubber sealing ring. The sealing ring is a main component for realizing the explosion-proof function in the lead-in device. In the design, the sealing ring is made of silicon rubber and nitrile rubber, the international hardness of the sealing ring is 65-70 degrees, and after the sealing ring is tightly pressed and sealed, the minimum axial size of the seal meets the minimum length requirement of a flame path.

Specifically, the temperature-sensitive sensor disclosed by the utility model is manufactured by using a special semiconductor, specifically a PN junction semiconductor thermosensitive element 1. The two sensors are physically very close and separated from each other by a distance, and have negligible thermal influence on each other. The sensor pair tracks the temperature of the media. The voltage drop of these sensors is proportional to temperature and operates over a wide temperature range with accuracy.

In this embodiment, 4 tops of mount pad are provided with connecting portion, seted up the cavity in the mount pad 4, the cavity intussuseption is filled with insulating fixed filler 3, insulating fixed filler 3 is the insulating epoxy of temperature resistant, the mounting hole has been seted up to 4 bottoms of mount pad, 2 tip and mounting hole riveting fixed of stainless steel protective sheath, one of them U type sensor 5 is the benchmark sensor, another U type sensor 5 is self-heating sensor, two parallel intervals of U type sensor 5 set up in 4 bottoms of mount pad.

One sensor is heated to be higher than the temperature of the medium and is a self-heating sensor, the other sensor has the same temperature with the medium, and the sensor with the same temperature with the medium is a reference sensor. An equal constant current flowing through the two sensors creates a voltage difference whose magnitude is inversely proportional to how much heat is absorbed away by the medium on the self-heating sensor. Since the flow velocity of the medium is proportional to the quantity of heat to be taken away, the current flow velocity of the medium can be known by measuring the voltage difference between the two sensors, and the flow rate of the medium can be known by calculation.

The two sensors are riveted on the mounting base according to a certain distance, the mounting base 4 is filled with temperature-resistant insulating epoxy resin to fix the sensors, and meanwhile, temperature-sensitive elements in the sensors are completely insulated and isolated from media and the environment.

When the device is used specifically, two sensors of the probe are placed in a flowing medium at the same time, one of the two sensors is heated by a self-heating mode to enable the temperature of the other sensor to be higher than that of the medium, and the temperature sensing information of the sensors is output; and the other one is the same as the medium temperature, and medium temperature information is output. The double sensors form a thermal temperature difference, and the sensors are self-heaters and temperature-sensing information samplers at the same time.

The utility model adopts a self-heating mode of the sensing element, and does not need to additionally heat the sensor, so that the processing and the installation are simple; the power consumption of the element is low, only 300mW is needed, and the service life is long; because the sampling probe is horizontally arranged in the U-shaped tube and basically fully immersed in a fluid medium, the contact area is maximized, so that a sampling signal is stable and sensitive, and the effective rate of the signal is at least more than 95%.

The probe is placed in the measured fluid, and the flow rate control point required to be controlled can be adjusted and set. When the medium flow reaches the control point, the state of the output switch signal is inverted, so that the downstream unit element or equipment is controlled to be switched on or switched off.

The present invention is not limited to the above preferred embodiments, and any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. The utility model provides a flame-proof type thermal difference formula flow switch which characterized in that: the heat differential type flow meter comprises a base body, wherein the top of the base body is provided with a mirror window upper cover, and the bottom of the base body is provided with a heat differential type flow probe; the top of the upper cover of the mirror window is provided with a hollowed-out window, a transparent mirror window sheet is arranged in the upper cover of the mirror window, the transparent mirror window sheet is fixed in the upper cover of the mirror window through a mirror window pressing sheet and a mirror window pressing ring, and the transparent mirror window sheet and the upper cover of the mirror window are sealed through epoxy resin; the differential flow probe of heat includes the mount pad, the mount pad bottom is provided with two U type sensors, U type sensor includes the stainless steel protective sheath of U type, install PN junction semiconductor temperature sensing element in the stainless steel protective sheath, PN junction semiconductor temperature sensing element's both ends are followed respectively stainless steel protective sheath both ends are stretched out, just PN junction semiconductor temperature sensing element with it has insulating fixed filler to fill between the stainless steel protective sheath.

2. The flameproof thermal differential flow switch of claim 1, characterized in that: the inner wall of the upper cover of the mirror window is provided with internal threads, the base body is provided with external threads, a sealing ring is arranged between the upper cover of the mirror window and the base body and is in threaded connection with the base body, M95-1.5 threads are adopted, the number of thread buttons is greater than 8, and the thread precision is 6g 6H.

3. The flameproof thermal differential flow switch of claim 1, characterized in that: the base body is provided with a functional circuit module and a data display module, and the data display module is over against the transparent sheet of the mirror window; the socket, the data display module and the thermal difference type flow probe are electrically connected with the functional circuit module respectively.

4. The flameproof thermal differential flow switch of claim 1, characterized in that: the base body is connected with the mounting base through screws, the base body and the mounting base are sealed through epoxy resin, and the height difference between the top surface of the seal and the bottom surface of the inner wall of the base body is 8-12 mm.

5. The flameproof thermal differential flow switch of claim 3, characterized in that: the mirror window upper cover surface is provided with forbidden identification area, the pedestal surface is provided with nameplate installation area, the connection socket side is provided with the ground connection sign.

6. The flameproof thermal differential flow switch of claim 1, characterized in that: the mounting base top is provided with connecting portion, sets up the cavity in the mounting base, the cavity intussuseption is filled with insulating fixed filler, insulating fixed filler is temperature resistant insulating epoxy.

7. The flameproof thermal differential flow switch of claim 1, characterized in that: the mounting base is provided with a mounting hole at the bottom, and the end part of the stainless steel protective sleeve is riveted and fixed with the mounting hole.

8. The flameproof thermal differential flow switch of claim 1, characterized in that: one of the U-shaped sensors is a reference sensor, and the other U-shaped sensor is a self-heating sensor.

9. The flameproof thermal differential flow switch of claim 1, characterized in that: the surface of the upper cover of the mirror window is provided with anti-skid convex ribs.