Mixing and conveying device for emulsified granular ammonium nitrate fuel oil explosives

Abstract

The invention belongs to the technical field of emulsified ammonium nitrate fuel oil explosive devices, and provides an emulsified granular ammonium nitrate fuel oil explosive mixing and conveying device. The device comprises a hopper, a tubular spiral conveying device and a rack, the tubular spiral conveying device comprises a first tubular spiral conveyor and a second tubular spiral conveyor, and waterproof cover plates are arranged on the upper portions of the first tubular spiral conveyor and the second tubular spiral conveyor. Heat exchange devices are arranged at the bottoms of the first pipe type spiral conveyor and the second pipe type spiral conveyor, and meters are arranged in the first connecting pipeline, the second connecting pipeline, the flexible connecting pipeline and the third connecting pipeline. By arranging the waterproof cover plate, the explosive is prevented from being exposed in the external environment, the explosive can be prevented from being affected with damp and going bad, and the emulsification effect is improved; the heat exchange device is arranged, so that the temperature increased by mixed friction can be reduced; and the metering device is arranged to accurately meter the produced emulsified granular ammonium nitrate fuel oil explosives, so that the mixing and conveying device has the characteristics of metering, cooling and waterproof functions.

Description

Technical Field

[0001] The invention belongs to the technical field of emulsified ammonium nitrate oil explosive device, and more specifically, relates to an emulsified granular ammonium nitrate oil explosive mixing and conveying device. Background Art

[0002] Ammonium oil fuel oil explosive refers to a powdered or granular explosive mixture composed of ammonium nitrate and fuel, which is mainly suitable for open-air blasting projects and blasting projects without the danger of methane and mine dust explosion. Products include: powdered ammonium oil fuel oil explosive, porous emulsified granular ammonium oil fuel oil explosive, heavy ammonium oil fuel oil explosive, granular sticky explosive, and thickened granular ammonium oil fuel oil explosive.

[0003] In the related prior art, the emulsified ammonium oil-fuel mixture device on the market cannot accurately weigh the emulsified amount during the production process of the emulsified ammonium oil-fuel mixture, and because the porous emulsified granular ammonium oil-fuel mixture has a strong hydrophilicity, and the existing device is not provided with waterproof measures, the porous emulsified granular ammonium oil-fuel mixture is easily affected by moisture and deteriorated, resulting in a poor emulsification effect of the product.

[0004] For this reason, the present invention provides a kind of emulsified granular ammonium oil-fuel mixture conveying device. Summary of the invention

[0005] In view of the above-mentioned problems existing in the prior art, the object of the present invention is to provide an emulsified granular ammonium nitrate oil explosive mixing and conveying device with the characteristics of metering, cooling and waterproofing functions.

[0006] The purpose of the present invention can be achieved by the following technical solutions:

[0007] An emulsified granular ammonium nitrate-oil mixture conveying device comprises a hopper, a tubular screw conveying device, and a frame, wherein the hopper is used to contain porous emulsified granular ammonium nitrate; the hopper and the tubular screw conveying device are both arranged on the frame, the tubular screw conveying device comprises a first tubular screw conveyor and a second tubular screw conveyor, the feed port of the first tubular screw conveyor is connected to the discharge port of the hopper through a first connecting pipe, the first tubular screw conveyor is connected to a diesel storage tank through a second connecting pipe, the discharge port of the first tubular screw conveyor is connected to the feed port of the second tubular screw conveyor through a flexible connecting pipe, the second tubular screw conveyor is connected to an emulsified matrix IBC tank through a third connecting pipe, a waterproof cover plate is arranged on the top of the first tubular screw conveyor and the second tubular screw conveyor, a heat exchange device is arranged on the bottom of the first tubular screw conveyor and the second tubular screw conveyor, and a meter is arranged inside the first connecting pipe, the second connecting pipe, the flexible connecting pipe and the third connecting pipe. The waterproof cover plate arranged on the tubular spiral conveying device can prevent it from being exposed to the external environment, thereby preventing the porous emulsified granular ammonium oil-fuel oil explosive from getting damp and deteriorating; at the same time, the temperature increased by the mixed friction can be cooled down by utilizing the heat exchange principle through the arranged heat exchange device; in addition, the first connecting pipe, the second connecting pipe, the flexible connecting pipe and the third connecting pipe are all provided with metering devices inside to accurately measure the production of the porous emulsified granular ammonium oil-fuel oil explosive.

[0008] As a further preferred technical solution of the present invention, the hopper includes a funnel portion, a rectangular trumpet-shaped silo portion is arranged above the funnel portion, the funnel portion of the hopper is connected to the first connecting pipe, and a bag breaker is arranged in the silo, and the bag breaker is in a polygonal pyramid shape. The bag breaker can be used to puncture the bag of porous emulsified granular ammonium nitrate placed from the upper opening of the silo portion.

[0009] As a further preferred technical solution of the present invention, the first tubular screw conveyor includes a first conveying tube shell, the first conveying tube shell is covered with a waterproof cover plate, a first conveying rod is arranged inside the first conveying tube shell, one end of the first conveying rod is transmission-connected to a driving mechanism, and the other end of the first conveying rod is provided with a first revolution counter;

[0010] The second tubular screw conveyor includes a second conveying tube shell, which is covered with a waterproof cover plate. A second conveying rod is arranged inside the second conveying tube shell. One end of the second conveying rod is transmission-connected to a driving mechanism, and the other end of the second conveying rod is provided with a second revolution counter.

[0011] As a further preferred technical solution of the present invention, the driving mechanism includes an axial driver and a base, the base includes a longitudinal seat plate, a bending plate and a driver seat plate, the lower extension plate wall on the left side of the bending plate is fixed to the bottom side wall of the longitudinal seat plate by screwing, and the upper extension plate wall on the right side of the bending plate is fixed to the bottom side wall of the driver seat plate by welding, so that a spacing area is formed between the longitudinal seat plate and the driver seat plate;

[0012] The body of the axial driver is fixed on the driver base plate, and the shaft of the axial driver passes through the driver base plate and the spacing area and is connected to the first conveying rod or the second conveying rod.

[0013] As a further preferred technical solution of the present invention, the axial drive is a rotary motor or a rotary cylinder.

[0014] As a further preferred technical solution of the present invention, the first tubular screw conveyor and the second tubular screw conveyor are both arranged obliquely on the corresponding rack, and the discharge ends of the two are higher than the feed ends, and the first tubular screw conveyor is located above the second tubular screw conveyor, so that the projection shape between the first tubular screw conveyor, the flexible connecting pipe and the second tubular screw conveyor is Z-shaped. The Z-shaped design structure can be used to perform layered processing on the production of porous emulsified granular ammonium nitrate, making the processing more complete and improving the processing efficiency.

[0015] As a further preferred technical solution of the present invention, the frame includes a first support frame and a second support frame, the cross-section of the first support frame is trapezoidal, the cross-section of the second support frame is triangular, the first support frame is placed at the bottom of the hopper, and the second support frame is placed at the bottom of the first tubular screw conveyor and the second tubular screw conveyor.

[0016] As a further preferred technical solution of the present invention, the heat exchange device includes a plurality of arched heat exchange tubes, and two adjacent arched heat exchange tubes are connected by the straight heat exchange tube, and the heat exchange device is respectively wound and fixed on the outer wall of the first tubular screw conveyor and the outer wall of the second tubular screw conveyor.

[0017] As a further preferred technical solution of the present invention, the flexible connecting pipe includes a fourth connecting pipe and a flexible pipe, one end of the flexible pipe is connected to the discharge port of the first tubular screw conveyor, the other end of the flexible pipe is connected to the fourth connecting pipe, and the other end of the fourth connecting pipe is connected to the feed port of the second tubular screw conveyor.

[0018] As a further preferred technical solution of the present invention, the first connecting pipe, the second connecting pipe, the third connecting pipe and the fourth connecting pipe all include a connecting pipe shell, a first blanking plate is fixed in the connecting pipe shell, a second blanking plate with resilience is hinged in the connecting pipe shell, and the second blanking plate is abutted with the meter. By designing the above structure, it is convenient to count the blanking of the processed porous emulsified granular ammonium nitrate raw material.

[0019] As described above, the emulsified granular ammonium oil-fuel mixture conveying device provided by the present invention has the following beneficial effects: in the processing and production process, by setting a waterproof cover plate to prevent it from being exposed to the external environment, the porous emulsified granular ammonium oil-fuel mixture can be prevented from getting damp and deteriorating, thereby improving the emulsification effect; the heat exchange device can be set to cool down the temperature increased by the mixed friction; a meter is set to accurately measure the production of the emulsified granular ammonium oil-fuel mixture, so that the mixing and conveying device of the present invention has the characteristics of metering, cooling and waterproofing functions.

[0020] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0022] Figure 1 One of the three-dimensional diagrams of an emulsified granular ammonium oil-fuel mixture conveying device applied for by the present invention;

[0023] Figure 2 The second stereoscopic diagram of an emulsified granular ammonium oil-fuel mixture conveying device applied for by the present invention;

[0024] Figure 3 A schematic structural diagram of a first tubular screw conveyor (shelling) of an emulsified granular ammonium oil-fuel mixture conveying device applied for by the present invention;

[0025] Figure 4 This is an enlarged cross-sectional view of the first connecting pipe applied for in the present invention from one perspective.

[0026] Summary of reference numerals and their descriptions:

[0027] 100, hopper; 110, hopper part; 120, silo part; 200, tubular screw conveyor; 210, first tubular screw conveyor; 211, first conveying tube shell; 212, waterproof cover plate; 213, first conveying rod; 214, driving mechanism; 215, first revolution counter; 216, second conveying tube shell; 217, second conveying rod; 218, second revolution counter; 220, second tubular screw conveyor; 221, heat exchange device; 222, arched heat exchange tube; 223, straight tube;

[0028] 230, axial driver; 240, base; 241, longitudinal seat plate; 242, bending plate; 243, driver seat plate; 244, spacing area;

[0029] 300, frame; 310, first support frame; 320, second support frame; 400, first connecting pipe; 410, connecting tube shell; 420, first blanking plate; 430, second blanking plate; 440, meter; 500, second connecting pipe; 600, third connecting pipe; 700, flexible connecting pipe; 710, fourth connecting pipe; 800, diesel storage tank; 900, emulsified matrix IBC tank. DETAILED DESCRIPTION

[0030] The following is a description of the implementation of the present invention by means of specific embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0031] It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions that the present invention can be implemented, so they have no substantial technical significance. Any modification of the structure, change in the proportional relationship, or adjustment of the size should still fall within the scope of the technical content disclosed by the present invention without affecting the effects that the present invention can produce and the purposes that can be achieved. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" quoted in this specification are only for the convenience of description, and are not used to limit the scope of the implementation of the present invention. The change or adjustment of the relative relationship should also be regarded as the scope of the implementation of the present invention without substantial changes in the technical content. The specific structure can be described with reference to the drawings of the patent application.

[0032] Example 1

[0033] The present invention provides an emulsified granular ammonium oil explosive mixing and conveying device, please refer to Figures 1 to 4As shown, it includes a hopper 100, a tubular screw conveying device 200, and a frame 300, wherein the hopper 100 is used to hold porous emulsified granular ammonium nitrate; the hopper 100 and the tubular screw conveying device 200 are both arranged on the frame 300, and the tubular screw conveying device 200 includes a first tubular screw conveyor 210 and a second tubular screw conveyor 220, wherein the feed port of the first tubular screw conveyor 210 is connected to the discharge port of the hopper 100 through a first connecting pipe 400, the first tubular screw conveyor 210 is connected to a diesel storage tank 800 through a second connecting pipe 500, and the first tubular screw conveyor 2 The discharge port of the first tubular screw conveyor 210 is connected to the feed port of the second tubular screw conveyor 220 through a flexible connecting pipe 700, and the second tubular screw conveyor 220 is connected to the emulsified matrix IBC tank 900 through a third connecting pipe 600. A waterproof cover plate 212 is provided on the upper part of the first tubular screw conveyor 210 and the second tubular screw conveyor 220, and a heat exchange device 221 is provided at the bottom of the first tubular screw conveyor 210 and the second tubular screw conveyor 220. A meter 440 is provided inside the first connecting pipe 400, the second connecting pipe 500, the flexible connecting pipe 700 and the third connecting pipe 600.

[0034] When using the present invention, please combine Figures 1 to 4 As shown, the porous emulsified granular ammonium oil-fuel oil explosive is poured into a feed hopper 100, and mixed and transported by a tubular screw conveyor 200. Different raw materials are injected into a diesel storage tank 800 and an emulsified matrix IBC tank 900 during transportation for further processing and production; during the processing and production process, the waterproof cover plate 212 provided on the tubular screw conveyor 200 prevents the porous emulsified granular ammonium oil-fuel oil explosive from being exposed to the external environment, thereby preventing the porous emulsified granular ammonium oil-fuel oil explosive from getting damp and deteriorating, thereby improving the emulsification effect; at the same time, by using the heat exchange device provided, the temperature increased by the mixed friction can be cooled down by utilizing the heat exchange principle; in addition, the first connecting pipe 400, the second connecting pipe 500, the flexible connecting pipe 700 and the third connecting pipe 600 are all provided with a meter 440 to accurately measure the production of the porous emulsified granular ammonium oil-fuel oil explosive.

[0035] Example 2

[0036] Based on Example 1, please combine Figure 1As shown, the hopper 100 includes a funnel portion 110, and a rectangular trumpet-shaped silo portion 120 is arranged above the funnel portion 110. The funnel portion 110 of the hopper 100 is connected to the first connecting pipe 400, and a bag breaker is arranged in the silo (not shown in the figure, the same below), and the bag breaker is in the shape of a polygonal pyramid. By providing a bag breaker, the bag containing porous emulsified granular ammonium nitrate placed from the upper opening of the silo portion 120 can be punctured, so that the porous emulsified granular ammonium nitrate can flow smoothly from the funnel portion 110 into the first tubular screw conveyor 210 for processing, so as to achieve the effect of puncturing the material.

[0037] Reference Figures 1 to 3 As shown, the first tubular screw conveyor 210 includes a first conveying tube shell 211, the first conveying tube shell 211 is covered with a waterproof cover plate 212, a first conveying rod 213 is arranged inside the first conveying tube shell 211, one end of the first conveying rod 213 is transmission-connected to a driving mechanism 214, and the other end of the first conveying rod 213 is provided with a first revolution counter 215;

[0038] The second tubular screw conveyor 220 includes a second conveying tube shell 216, which is covered with a waterproof cover plate 212. A second conveying rod 217 is arranged inside the second conveying tube shell 216. One end of the second conveying rod is transmission-connected to the driving mechanism 214, and the other end of the second conveying rod 217 is provided with a second revolution counter 218.

[0039] Specifically, please combine Figure 1 and Figure 3 As shown, the driving mechanism 214 includes an axial driver 230 and a base 240, wherein the base 240 includes a longitudinal seat plate 241, a bending plate 242 and a driver seat plate 243, wherein the lower left side extending plate wall of the bending plate 242 is fixed to the bottom side wall of the longitudinal seat plate 243 by screwing, and the upper right side extending plate wall of the bending plate 242 is fixed to the bottom side wall of the driver seat plate 243 by welding, so that a spacing area 244 is formed between the longitudinal seat plate 241 and the driver seat plate 243;

[0040] The body of the axial driver 230 is fixed on the driver base plate 243 , and the shaft of the axial driver 230 passes through the driver base plate 243 and the spacing area 244 and is connected to the first conveying rod 213 or the second conveying rod 217 .

[0041] It should be noted that the axial driver 230 is a rotary motor or a rotary cylinder.

[0042] Example 3

[0043] Based on Example 1, please combine Figure 1 and Figure 2 As shown, the first tubular screw conveyor 210 and the second tubular screw conveyor 220 are both arranged obliquely on the corresponding racks, and the discharge ends of the two are higher than the feed ends. The first tubular screw conveyor 210 is located above the second tubular screw conveyor 220, so that the projection shape between the first tubular screw conveyor 210, the flexible connecting pipe 700 and the second tubular screw conveyor 220 is Z-shaped. With this Z-shaped design, the production of porous emulsified granular ammonium nitrate can be processed in layers, making the processing more complete and improving the processing efficiency.

[0044] Specifically, please combine Figure 1 As shown, the frame 300 includes a first support frame 310 and a second support frame 320, the cross-section of the first support frame 310 is trapezoidal, and the cross-section of the second support frame 320 is triangular, the first support frame 310 is placed at the bottom of the hopper 100, and the second support frame 320 is placed at the bottom of the first tubular screw conveyor 210 and the second tubular screw conveyor 220.

[0045] Please combine Figure 1 and Figure 2 As shown, the heat exchange device 221 includes a plurality of arched heat exchange tubes 222 and a plurality of straight tubes 223. Two adjacent arched heat exchange tubes 222 are connected via the straight heat exchange tubes 223. The heat exchange device 221 is respectively wound and fixed on the outer wall of the first tubular screw conveyor 210 and the outer wall of the second tubular screw conveyor 220. The heat exchange device 221 is respectively wound and fixed on the outer wall of the first tubular screw conveyor 210 and the outer wall of the second tubular screw conveyor 220.

[0046] The flexible connecting pipe 700 includes a fourth connecting pipe 710 and a flexible pipe (not shown in the figure, all below), one end of the flexible pipe is connected to the discharge port of the first tubular screw conveyor 210, the other end of the flexible pipe is connected to the fourth connecting pipe 710, and the other end of the fourth connecting pipe 710 is connected to the feed port of the second tubular screw conveyor 220.

[0047] Example 4

[0048] Based on Example 1, please combine Figure 1 and Figure 4As shown, the first connecting pipe 400, the second connecting pipe 500, the third connecting pipe 600 and the fourth connecting pipe 710 all include a connecting pipe shell 410, in which a first blanking plate 420 is fixed, and a second blanking plate 430 with rebound performance is hinged in the connecting pipe shell 410, and the second blanking plate 430 is abutted against the meter 440. By designing the above-mentioned structure, part of the porous emulsified granular ammonium nitrate raw material will contact the first blanking plate 420 and the second blanking plate 430. The first blanking plate 420 and the second blanking plate 430 each have a buffering blanking function, which slows down the input speed of the raw material and helps the processing and production, and also can avoid the phenomenon of raw material clogging the pipeline; and the second blanking plate 430 has resilience. When the porous emulsified granular ammonium nitrate raw material enters from the feed port of the connecting tube shell 410, the porous emulsified granular ammonium nitrate raw material intermittently contacts the second blanking plate 430, thereby achieving the purpose of facilitating its abutment and cooperation with the meter 440 for statistical measurement, and further having the technical effect of facilitating the statistical blanking of the processed porous emulsified granular ammonium nitrate raw material.

[0049] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

Claims

1. An emulsified granular ammonium nitrate oil mixture conveying device, comprising a hopper, a tubular screw conveying device, and a frame, wherein the hopper is used to hold porous emulsified granular ammonium nitrate; characterized in that: The hopper and the tubular screw conveyor are both arranged on a frame, and the tubular screw conveyor includes a first tubular screw conveyor and a second tubular screw conveyor, the feed port of the first tubular screw conveyor is connected to the discharge port of the hopper through a first connecting pipe, the first tubular screw conveyor is connected to a diesel storage tank through a second connecting pipe, the discharge port of the first tubular screw conveyor is connected to the feed port of the second tubular screw conveyor through a flexible connecting pipe, the second tubular screw conveyor is connected to an emulsified matrix IBC tank through a third connecting pipe, a waterproof cover plate is arranged on the top of the first tubular screw conveyor and the second tubular screw conveyor, a heat exchange device is arranged on the bottom of the first tubular screw conveyor and the second tubular screw conveyor, and meters are arranged inside the first connecting pipe, the second connecting pipe, the flexible connecting pipe and the third connecting pipe.

2. a kind of emulsified granular ammonium oil-fuel mixture conveying device according to claim 1, is characterized in that, The hopper comprises a funnel portion, a rectangular trumpet-shaped silo portion is arranged above the funnel portion, the funnel portion of the hopper is connected to the first connecting pipe, and a bag breaker is arranged in the silo, and the bag breaker is in a polygonal pyramid shape.

3. a kind of emulsified granular ammonium oil-fuel mixture conveying device according to claim 1, is characterized in that, The first tubular screw conveyor comprises a first conveying tube shell, the first conveying tube shell is covered with a waterproof cover plate, a first conveying rod is arranged inside the first conveying tube shell, one end of the first conveying rod is transmission-connected to a driving mechanism, and the other end of the first conveying rod is provided with a first revolution counter; The second tubular screw conveyor includes a second conveying tube shell, which is covered with a waterproof cover plate. A second conveying rod is arranged inside the second conveying tube shell. One end of the second conveying rod is transmission-connected to a driving mechanism, and the other end of the second conveying rod is provided with a second revolution counter.

4. a kind of emulsified granular ammonium oil-fuel mixture conveying device according to claim 3, is characterized in that, The driving mechanism includes an axial driver and a base, the base includes a longitudinal seat plate, a bending plate and a driver seat plate, the lower extension plate wall on the left side of the bending plate is fixed to the bottom side wall of the longitudinal seat plate by screwing, and the upper extension plate wall on the right side of the bending plate is fixed to the bottom side wall of the driver seat plate by welding, so that a spacing area is formed between the longitudinal seat plate and the driver seat plate; The body of the axial driver is fixed on the driver base plate, and the shaft of the axial driver passes through the driver base plate and the spacing area and is connected to the first conveying rod or the second conveying rod.

5. a kind of emulsified granular ammonium oil-fuel mixture conveying device according to claim 4, is characterized in that, The axial drive is a rotary motor or a rotary cylinder.

6. a kind of emulsified granular ammonium oil-fuel mixture conveying device according to claim 3, is characterized in that, The first tubular screw conveyor and the second tubular screw conveyor are both arranged obliquely on the corresponding frames, and the discharge ends of the two are higher than the feed ends. The first tubular screw conveyor is located above the second tubular screw conveyor, so that the projection shape between the first tubular screw conveyor, the flexible connecting pipe and the second tubular screw conveyor is Z-shaped.

7. according to a kind of emulsified granular ammonium oil-fuel mixture conveying device described in claim 1-6 any one, it is characterized in that, The frame includes a first support frame and a second support frame, the cross section of the first support frame is trapezoidal, the cross section of the second support frame is triangular, the first support frame is placed at the bottom of the hopper, and the second support frame is placed at the bottom of the first tubular screw conveyor and the second tubular screw conveyor.

8. according to a kind of emulsified granular ammonium oil-fuel mixture conveying device described in claim 1-6 any one, it is characterized in that, The heat exchange device includes a plurality of arched heat exchange tubes, and two adjacent arched heat exchange tubes are connected via the straight heat exchange tube. The heat exchange device is respectively wound and fixed on the outer side wall of the first tubular screw conveyor and the outer side wall of the second tubular screw conveyor.

9. according to a kind of emulsified granular ammonium oil-fuel mixture conveying device described in claim 1-6 any one, it is characterized in that, The flexible connecting pipe includes a fourth connecting pipe and a flexible pipe, one end of the flexible pipe is connected to the discharge port of the first tubular screw conveyor, the other end of the flexible pipe is connected to the fourth connecting pipe, and the other end of the fourth connecting pipe is connected to the feed port of the second tubular screw conveyor.

10. A kind of emulsified granular ammonium oil-fuel mixture conveying device according to claim 9, characterized in that, The first connecting pipe, the second connecting pipe, the third connecting pipe and the fourth connecting pipe all include a connecting pipe shell, a first blanking plate is fixed in the connecting pipe shell, a second blanking plate with resilience is hinged in the connecting pipe shell, and the second blanking plate is in abutment with the meter.

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