RU97828U1 - PROTECTIVE DEVICE FOR THE PITO-Prandtl Measuring Tube - Google Patents

Abstract

 1. The protective device of the Pitot-Prandtl measuring tube, containing a sealing and fixing unit, on one of the two ends of which there is an element for connecting the unit to the stop valves of the pipeline, and the other end is equipped with an oil seal, through which a thick-walled tube of high-strength alloy steel is placed, placed in the sealing -fixing unit with the possibility of its limited axial reciprocating movement, provided at one end with a stop restrictive element, T is placed at its other end a sharp tee, characterized in that the T-shaped tee is made L-shaped, that is, a rectangular slot in size with the size of the upper, with mutually perpendicular bends, part of the Pitot-Prandtl tube, the lower measuring part of which protrudes from the thick-walled the tube to the nominal value of H, in the gap between the restrictive element of the latter and the Pitot-Prandtl tube, a seal is placed, while both branches of the T-tee and mutually perpendicular bends of the Pitot-Prandtl tube are equal to length, in the body of the T-shaped tee around the outlets of the Pitot-Prandtl tube, bores are made in which centering metal washers and bushings of sealing material are put on the outlets of the Pitot-Prandtl tube, and connecting threads are made on the outside of each of these outlets of the T-shaped tee for union end nuts of discharge hoses. ! 2. The protective device for the Pitot-Prandtl measuring tube according to claim 1, characterized in that the T-shaped tee is equipped with an eye and / or an arm for hanging and / or a hard hook

Description

The utility model relates to devices for measuring the volume and / or mass of fluids by passing them in a continuous stream with a measurement of its velocity and / or velocity head as the difference between the total and static flow pressures using the well-known Pitot-Prandtl measuring tube and is designed to operate on toxic, chemically aggressive and / or explosive fluids.

The prior art in this area is characterized by the presence in the information field (patent and technical documentation, Internet, reference literature) of descriptions of such structures, which are described for example in [USSR, A.S. 453599, G01P 5/16, 02.10.72; USSR, A.S. 885894, G01P 5/16, 11/13/79; RU, 2152017 C1, G01N 1/22, 12/17/98; RU, 60724 U1, G01N 1/22, 09/26/06].

In wall-limited fluid flows (ventilation ducts, gas and chimneys, pipelines of any local networks or main pipelines), the well-known Pitot-Prandtl pipe [Polytechnic Dictionary, M., Soviet Encyclopedia 1989 p.380, column 2; Popov S.G., Measurement of air flow, M.-L., 1947; Physical measurements in gas dynamics and during combustion, translation from English, parts 1-2, M., 1957; Gorlin SM, Slezinger II, Aeromechanical measurements, M., 1964], the inlet measuring part of which is placed in the stream by means of some sealing-fixing unit on the wall of the object to position the tube in the proper position. The channels of the opposite part of the tube are connected to measuring the total and static pressure of the fluid, the readings of which characterize (with appropriate conversion) the productivity of the pipeline, that is, the flow rate. However, it should be noted that for a number of reasons, modern Pitot-Prandtl tubes have acquired a very specific form, shape and size, for example, the optimal ones are: outer diameter up to 8 mm, maximum length up to 3 m, measuring part with a hemispherical end and the opposite part with equal mutually perpendicular bends to each other about 50 mm long, one of which is coaxial to the tube itself. Note, moreover, that the Pitot-Prandtl tube is an all-metal non-separable structure with calibrated holes in its measuring part, it is a means of measurement [see in the State Register of the SI RF RF number 21099-06], that is, it must undergo periodic verification in the metrological service and no other functions for this product are specified by operational standards. The disadvantages of the known Pitot-Prandtl tubes, not touching their measuring qualities, can and should be attributed to their vulnerability to damage during transportation and repeated installation and dismantling at the measurement site, since these tubes are not always stationary means of instrumentation and A. In addition, modern the Pitot-Prandtl tube does not have sufficient rigidity, which, when the cantilever (with respect to the sealing-fixing assembly on the pipe wall) ends and small diameters is significant, limits its use, and taking into account I specificity measurements in environments of reactive and / or have toxicity to varying degrees, as well as in explosive environments, making it unsafe to operate and requires no additional protection and precautionary means.

The closest to the claimed object in terms of essential features, that is, its prototype, is a device for sampling along the pipeline from the lower to the upper generatrix of the pipe in continuous or discrete mode [RU, 2171891 C2, 09/28/99], which is a sealing-fixing assembly with an element of its attachment to a shut-off straight-through valve on the pipe wall and thick-walled, up to 4 mm (with its outer diameter 16 mm), a tube of high-strength alloy steel with the possibility of its limited axial reciprocating relative movement relative to this node. The end of the outer part of the tube is equipped with an angular shut-off valve with a T-shaped body and a conical element locking the valve seat, coaxial with the tube.

The known design could be used with some design refinement as a Pitot-Prandtl tube directly, however, to expand the range of measuring instruments for this purpose, firstly, there is no urgent need for existing and certified standard sizes, and secondly, it is not economically feasible.

Therefore, the technical task of creating the claimed utility model is to create a reliable means of protecting the Pitot-Prandtl pipe with the appropriate design refinement of the already known prototype object, which ultimately allows the reliable operation of the Pitot-Prandtl pipe in conditions, for example, of an oil or gas production enterprise, i.e. in the field with very wide variations in the size of pipelines, as well as speeds, pressures, temperatures and physico-chemical properties of fluids.

The problem is solved in that in a known design containing a sealing-fastening assembly, on one of the two ends of which there is an element for connecting it to the stop valves of the pipeline, and the other end is equipped with an oil seal, through which a thick-walled tube made of high-strength alloy steel is placed, placed in a sealing - a mounting unit with the possibility of its limited axial reciprocating movement. The tube at one end is equipped with a stop restrictive element, at its other end there is a T-shaped tee, in which an L-shaped, that is, rectangular in plan, slot with the size of the upper placed in the T-shaped tee, with mutually perpendicular bends, is made, part Pitot-Prandtl tubes, the lower measuring part of which protrudes from the thick-walled tube by a standard value N. In the gap between the restrictive element of the thick-walled tube and the Pitot-Prandtl tube, a seal is placed, with both T-shaped taps tee and mutually perpendicular bends of the Pitot-Prandtl tube are equal in length. Bores are made in the body of the tee around the branches of the Pitot-Prandtl pipe, in which centering washers and bushings of sealing material are put on the branches of the Pitot-Prandtl pipe, while on the outside of each of the branches with bores of the T-shaped tee, connecting threads for cap end outlet hose nuts. The T-shaped tee of a thick-walled tube can additionally be equipped with an eye and / or an arm for hanging and / or rigid attachment to any supporting structure with a significant cantilever protrusion of the part of the thick-walled tube protruding from the pipeline.

A comparative analysis of the claimed device, as a set of essential features (including distinctive ones), with solutions known from the regulatory, technical and patent documentation, allows us to argue that the proposed technical solution meets the "criteria" of the utility model, that is, it has "novelty" and "Industrial applicability."

The utility model provides safe and convenient operation of the Pitot-Prandtl tube, while allowing, if necessary, to replace the latter with another, similar, without dismantling the entire device. To do this, it is enough to raise the thick-walled tube to the stop of the stopper in the sealing-mounting assembly, close the pipeline locking device, disconnect the end union nuts of the outlet hoses from the T-tee, remove the Pitot-Prandtl tube through the L-shaped slot, after removing the centering washers and bushings from the sealing material, put another Pitot-Prandtl tube and carry out all operations in the reverse order.

The utility model is illustrated by graphic materials, where in the drawing (Fig. 1) a general view of the device is shown, and in Fig. 2 - the lower part of the device before it is extended to the measuring position in the pipeline cavity.

The protective device for the Pitot-Prandtl measuring tube contains (see Fig. 1 and Fig. 2) a sealing and fixing unit 1, on one of its two ends an element 2 for connecting the unit to the stop valves of the pipeline is made, and the other end is provided with an oil seal 3, through which missed a thick-walled tube 4 made of high-strength alloy steel, placed in the sealing-fixing unit 1 with the possibility of its limited axial reciprocating movement. A thick-walled tube 4 at one end is provided with a stop restrictive element 5, and a T-shaped tee 6 is placed on its other end 6. A T-shaped tee 6 is made L-shaped, that is, a rectangular slot 7 in size with a size placed in T- the upper tee, with mutually perpendicular bends, the part of the Pitot-Prandtl tube, the lower measuring part of which protrudes from the thick-walled tube 4 by a standard value N. In the gap between the restrictive element 5 of the thick-walled tube 4 and the Pitot-Prandtl tube seal 8. Both branches 9 and 10 of the T-shaped tee 6 and the mutually perpendicular branches of the Pitot-Prandtl tube are equal in length. Bores 11 and 12 are made in the body of the T-shaped tee 6 around the branches of the Pitot-Prandtl tube, in which centering metal washers 13 and 14 and bushings 15 and 16 of sealing material are put on the branches of the Pitot-Prandtl tube, and on the outside of each of these T-shaped tee bends 6 have connecting threads 17 for union end nuts of the outlet hoses.

The T-shaped tee 6 is equipped with an eye and / or an arm 18 for hanging and / or rigidly fastening to any supporting structure with a significant cantilever extension of the part of the thick-walled tube 4 protruding from the pipeline.

Before the operation of the facility / structure, the following assembly operations are provided:

- a T-shaped tee 6 is screwed onto the upper part of the thick-walled tube 4;

- inside the thick-walled tube 4 with a T-shaped tee 6, a Pitot-Prandtl tube is placed, which is fixed in the T-shaped tee 6 using centering metal washers 13 and 14 and bushings 15 and 16 of sealing material;

- to each of the branches of the T-shaped tee 6 on the connecting threads 17 are screwed cap end nuts of the outlet hoses, sealing bushings 15 and 16;

- thick-walled tube 4 through the gland 3 is inserted into the sealing-mounting unit 1;

- a seal 8 is installed on the lower part of the thick-walled tube 4 and a stop restrictive element 5 is screwed on, the thick-walled tube 4 rises upwards in the sealing-fixing unit 1 until it stops.

The protective device for the measuring tube Pitot-Prandtl works as follows. Sealing and mounting unit 1 is attached to the shut-off valve on the pipeline. The oil seal 3 is tightened. The discharge hoses are connected to the secondary device. The stopcock opens. Thick-walled tube 4 with a Pitot-Prandtl tube placed inside it falls into the cavity of the pipeline to a predetermined depth. Flow metering is in progress. After measurement, operations are carried out in reverse order.

An example of a specific implementation of a utility model is a design developed, manufactured, tested and recommended for use with the following design parameters:

- sealing and mounting unit D _at 20;

- N = 100 mm;

- thick-walled tube d _n = 16 mm, δ = 3.5 mm.

In addition to the above, it can be noted that the Pitot-Prandtl tube moved by the measuring part along the flow cross-section allows a fluid sample to be taken to determine its physicochemical parameters through shut-off and switch devices (not shown in the figures) on the outlet hoses between the measuring device and the Pitot tube -Prandtl.

Claims (2)

1. The protective device of the Pitot-Prandtl measuring tube, containing a sealing and fixing assembly, on one of the two ends of which there is an element for connecting the assembly to the stop valves of the pipeline, and the other end is equipped with an oil seal, through which a thick-walled tube of high-strength alloy steel is placed, placed in the sealing -fixing unit with the possibility of its limited axial reciprocating movement, provided at one end with a stop restrictive element, at its other end is placed T- a sharp tee, characterized in that the T-shaped tee is made L-shaped, that is, a rectangular slot in size with the size of the upper, with mutually perpendicular bends, part of the Pitot-Prandtl tube, the lower measuring part of which protrudes from the thick-walled the tube to the nominal value of H, in the gap between the restrictive element of the latter and the Pitot-Prandtl tube, a seal is placed, while both branches of the T-tee and mutually perpendicular bends of the Pitot-Prandtl tube are equal to length, in the body of the T-shaped tee around the outlets of the Pitot-Prandtl tube, bores are made in which centering metal washers and bushings of sealing material are put on the outlets of the Pitot-Prandtl tube, and connecting threads are made on the outside of each of these outlets of the T-shaped tee for union end nuts of discharge hoses. 2. The protective device for the Pitot-Prandtl measuring tube according to claim 1, characterized in that the T-shaped tee is equipped with an eye and / or bracket for hanging and / or rigid attachment to any supporting structure with a significant cantilever overhang of the part protruding from the pipeline thick-walled tube.