Cement pipe hand digging type pipe jacking construction closed space air supply and exhaust system

Abstract

The utility model discloses a cement pipe hand digging type pipe jacking construction closed space air supply and exhaust system which comprises an original soil layer, a working pipe, a curved surface air pipe, an air supply box and an oxygen content detector, the working pipe is arranged in the original soil layer, the curved surface air pipe is installed on the inner top of the working pipe, a plurality of air supply outlets are formed in the curved surface air pipe, and the oxygen content detector is arranged on the air supply box. The multiple air supply outlets are located in the position close to one side of a working area in the working pipe, the air supply box is installed on the other side of the curved-surface air pipe, the air supply end of the air supply box is communicated with the interior of the curved-surface air pipe, and the oxygen content detector is installed in the working area in the working pipe. The air supply box is provided with a signal receiver used for receiving signals sent by the oxygen content detector. The noise reduction device is high in safety and low in manufacturing cost, meanwhile, the comfort level of the working environment is remarkably improved by controlling the noise level, and the noise reduction device has good economical efficiency and practicability.

Description

Technical Field

[0001] The utility model relates to the technical field of exhaust ventilation, in particular to an air supply and exhaust system for a confined space in cement pipe hand-dug jacking construction. Background Art

[0002] Currently, the ventilation systems used in confined spaces during hand-dug concrete pipe jacking construction often use a nozzle-type blasting method to deliver air to the interior of the pipe. When the soil-dumping railcar is transporting soil outside, the two-speed blower must be moved away from the nozzle, stopping air supply within the confined pipe. When the soil-dumping railcar reenters the pipe, the two-speed blower must be repositioned at the nozzle to resume air supply. This is time-consuming and labor-intensive, and cannot guarantee uninterrupted ventilation within the confined space. Due to the limited range of the two-speed blower, when the cement pipe exceeds its range, the innermost working area of ​​the pipe cannot be effectively ventilated, and the oxygen content in the working environment cannot be guaranteed, significantly reducing work safety. Utility Model Content

[0003] In order to solve the above problems, the utility model provides a confined space air supply and exhaust system for cement pipe hand-dug jacking construction to solve the problem.

[0004] To achieve the above objectives, this application provides the following technical solutions:

[0005] A confined space ventilation and exhaust system for cement pipe hand-dug jacking construction comprises an original soil layer, a working pipe, a curved air duct, an air supply box, and an oxygen content detector. The working pipe is placed in the original soil layer, the curved air duct is installed on the top of the working pipe, a plurality of air supply ports are provided on the curved air duct, and the plurality of air supply ports are located on one side close to the working area in the working pipe. The air supply box is installed on the other side of the curved air duct, and the air supply end of the air supply box is connected to the inside of the curved air duct. The oxygen content detector is installed in the working area in the working pipe; the air supply box is provided with a signal receiver for receiving signals sent by the oxygen content detector.

[0006] It is further configured as follows: a plurality of air supply ports are opened on the lower surface of the curved air duct.

[0007] It is further configured as follows: a tie belt is provided in the curved air duct.

[0008] It is further configured as follows: a plurality of the curved air ducts are provided, and the plurality of the curved air ducts are connected by cables.

[0009] It is further configured as follows: a plurality of first embedded steel plates are horizontally arranged on the inner top of the working tube, and a strong magnetic hook is provided on the lower surface of the first embedded steel plate; air duct hanging points are evenly arranged on the outer top of the curved air duct, and the strong magnetic hook passes through the air duct hanging points and is adsorbed on the first embedded steel plate.

[0010] It is further configured as follows: a plurality of second embedded steel plates are horizontally arranged on the inner side of the working tube, a magnetic block is arranged on the oxygen content detector, and the oxygen content detector is magnetically attracted to the second embedded steel plate through the magnetic block.

[0011] It is further configured that: an air supply module and a refrigeration module are provided inside the air supply box.

[0012] It is further configured that the calculation formula for the height of the curved air duct is:

[0013] Where h represents the height of the curved duct; R represents the inner radius of the working tube; and N represents the number of workers inside the working tube.

[0014] It is further configured that the calculation formula for the cross-sectional length of the curved air duct is:

[0015] l = 0.78πR; where l represents the cross-sectional length of the curved duct; and R represents the inner radius of the working tube.

[0016] The calculation formula for the number of air outlets is:

[0017] Where n represents the number of air outlets; N represents the number of workers inside the working tube; and d represents the aperture of the air outlet.

[0018] Compared with the prior art, the beneficial technical effects of the present invention are:

[0019] 1. This utility model abandons the traditional air duct materials and shapes and uses flame-retardant fiber fabric curved air ducts. The system cost is low and the installation space is small, ensuring that the effective working space inside the working pipe is not affected and the soil dumping rail car can operate normally;

[0020] 2. Compared with traditional nozzle air blasting, this utility model is not affected by the length of the cement pipe. The curved air duct can be connected and extended by zipper splicing, and fresh air is continuously and directly delivered to the working area. The air temperature and humidity are controllable, which greatly improves the safety and comfort of the working environment. This system has two working modes: normal air supply and emergency air supply. The two working modes can be switched automatically according to the oxygen concentration in the working area, ensuring that the oxygen concentration in the working area always meets the requirements of the operators, greatly improving the safety of the working environment.

[0021] In summary, the air supply and exhaust system provided by the utility model has high safety and low cost. At the same time, by controlling the noise level, it significantly improves the comfort of the working environment and has good economy and practicality. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0023] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0024] Figure 2 It is a front view of the utility model;

[0025] Figure 3 for Figure 2 A magnified schematic diagram of part A in the middle;

[0026] Figure 4 This is a schematic diagram of the appearance of the curved air duct of the present utility model;

[0027] Figure 5 This is a schematic diagram of the internal structure of the curved air duct of the present invention;

[0028] Figure 6 This is a schematic diagram of the connection of multiple curved air ducts in the present invention.

[0029] Figure numerals: 1. original soil layer; 2. working pipe; 3. curved air duct; 4. air supply box; 5. oxygen content detector; 6. first embedded steel plate; 7. strong magnetic hook; 8. tie belt; 9. air duct hanging point; 10. second embedded steel plate; 11. magnetic block. DETAILED DESCRIPTION

[0030] The following is a clear and complete description of the technical solution of the present invention in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0031] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating positions or relationships, are based on the positions or relationships shown in the accompanying drawings and are intended solely to facilitate the description of this utility model and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0032] In the description of this utility model, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; direct connections, indirect connections through an intermediate medium, and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on specific circumstances.

[0033] Example

[0034] Reference Figures 1-6 , which is a confined space ventilation system for cement pipe hand-dug jacking construction disclosed in the utility model, comprising an original soil layer 1, a working pipe 2, a curved air duct 3, an air supply box 4, and an oxygen content detector 5. The working pipe 2 is a cement pipe and is buried in the original soil layer 1. A plurality of first embedded steel plates 6 are horizontally arranged on the inner top of the working pipe 2, and a strong magnetic hook 7 is provided on the lower surface of the first embedded steel plate 6;

[0035] In this embodiment, multiple curved air ducts 3 are provided, and the multiple curved air ducts 3 are connected by cables. Furthermore, the multiple curved air ducts 3 are all made of flame-retardant fiber fabric, and a tie band 8 is provided inside them to ensure that the air ducts have a curved shape when the internal pressure is positive. The curvature of the curved air duct 3 is the same as that of the cement pipe, so as to minimize the space inside the cement pipe and ensure that the air ducts do not affect the manual excavation operation.

[0036] Furthermore, duct hanging points 9 are evenly arranged on the outer top of the curved duct 3. Strong magnetic hooks 7 pass through the duct hanging points 9 and are adsorbed on the first embedded steel plate 6, thereby hanging the curved duct 3 on the inner top side of the working pipe 2.

[0037] The calculation formula for the height of the curved air duct 3 is:

[0038]

[0039] Where h represents the height of the curved duct; R represents the inner radius of the working tube; and N represents the number of workers inside the working tube.

[0040] The calculation formula for the cross-sectional length of the curved air duct 3 is:

[0041] l=0.78πR (Formula 2);

[0042] Where l represents the cross-sectional length of the curved duct; R represents the inner radius of the working tube.

[0043] A plurality of air supply ports are provided on the inner bottom wall of the curved air duct 3;

[0044] In this embodiment, the air supply port is opened on a side close to the working area in the working tube.

[0045] The calculation formula for the number of air outlets is:

[0046]

[0047] Where n represents the number of air outlets; N represents the number of workers inside the working tube; d represents the aperture of the air outlet, which is 2 cm.

[0048] The air supply box 4 is arranged on the side of the curved air duct 3 farthest from the air supply port. Specifically, the air supply end of the air supply box 4 is connected to the interior of the curved air duct 3. The interior of the air supply box 4 is provided with an air supply module and a refrigeration module to meet the temperature and humidity requirements of the staff.

[0049] A plurality of second embedded steel plates 10 are horizontally arranged on the inner side of the working tube 2. A magnetic block 11 is provided on the oxygen content detector 5. The oxygen content detector 5 is magnetically attracted to the second embedded steel plates 10 through the magnetic block 11.

[0050] The air supply box 4 is provided with a signal receiver for receiving the signal sent by the oxygen content detector 5. In order to ensure that the oxygen content in the confined space of the cement pipe hand-dug jacking construction meets the personnel needs.

[0051] In this embodiment, the refrigeration module can adopt the form of "semiconductor refrigeration plate + heat exchange fin plate", or use a window air conditioner. Both achieve refrigeration by consuming electrical energy. The refrigeration working principle of the refrigeration module is a conventional technology in the relevant technical field and will not be described in detail here.

[0052] The air supply module adopts a two-speed fan. The low-speed operation state of the two-speed fan is used for normal air supply, and the high-speed operation state of the two-speed fan is used for emergency air supply. Specifically, when the oxygen concentration in the working area is lower than the lower limit value, the oxygen content detector 5 sends a signal to the signal receiver of the air supply box 4, and the fan of the air supply box 4 is immediately switched from the low-speed normal air supply operation state to the high-speed emergency air supply state, thereby increasing the air supply volume in the working area. When the oxygen concentration in the working area reaches the upper limit value, the oxygen content detector 5 sends a signal to the signal receiver of the air supply box 4, and the operation state of the fan of the air supply box 4 is switched back to the low-speed normal air supply state, thereby realizing the automatic maintenance function of the oxygen content in the working area.

[0053] The utility model directly supplies air to the working area, so that the wind pressure in the working area inside the working pipe 2 is increased, forming a wind pressure difference from the working area to the inlet end of the working pipe 2, and an air flow direction from the working area of ​​the working pipe 2 to the inlet of the cement pipe is formed in the pipeline, so that the air flow inside the cement pipe is unobstructed.

[0054] Furthermore, the cross section of the connection between the air box 4 of the curved air duct 3 and the curved air duct 3 is taken as cross section 1, and the pressure at this cross section is P1 (i.e., the side pressure of the curved air duct). The cross section at the air outlet of the curved air duct is taken as cross section 2, and the pressure at this cross section is P2. The pressure drop between cross section 1 and cross section 2 is P 1-2 , according to Bernoulli's equation:

[0055] P1=P 1-2 +0.25ρ(Formula 4);

[0056] Where ρ is the air density. As can be seen from Formula 4, when selecting the fabric material for the curved air duct 3, it is only necessary to ensure that the material pressure is greater than the side pressure P1 of the curved air duct.

[0057] Furthermore, the cross section of the working pipe at the air outlet is taken as cross section 3, the pressure at this cross section is P3, the cross section at the outlet of the working pipe 2 is taken as cross section 4, the pressure at this cross section is P4, and the pressure drop between cross sections 3 and 4 is P 3-4 , according to Bernoulli's equation:

[0058] P3=P 3-4 (Formula 5);

[0059] According to the "Design Code for Heating, Ventilation and Air Conditioning of Industrial Buildings GB50019-2015", the pressure difference between different air conditioning areas should be 5Pa~10Pa, so P3=P 3-4 =5Pa~10Pa, the ventilation requirements can be met; when P3 is greater than the set value, a wind curtain is set inside the curved air duct. When P3 is less than the set value, P3 can be increased by adding a fan to meet the ventilation requirements.

[0060] This utility model also takes noise control into consideration to improve the comfort of the working environment. The calculation formula for the sound power level is:

[0061]

[0062] The working principle and beneficial effects of the utility model are as follows:

[0063] The utility model abandons the traditional air duct material and shape and uses the flame-retardant fiber fabric curved air duct 3, which has a low system cost and requires a small installation space, ensuring that the effective working space inside the working pipe 2 is not affected and the soil dumping rail car can operate normally;

[0064] Compared with traditional nozzle air blasting, the utility model is not affected by the length of the cement pipe. The curved air duct 3 can be extended by zipper connection and splicing, and fresh air is continuously and directly delivered to the working area. The air temperature and humidity are controllable, which greatly improves the safety and comfort of the working environment. The system has two working modes: normal air supply and emergency air supply. The two working modes can be switched automatically according to the oxygen concentration in the working area, ensuring that the oxygen concentration in the working area always meets the requirements of the operators, greatly improving the safety of the working environment.

[0065] In summary, the utility model provides a confined space air supply and exhaust system for cement pipe hand-dug jacking construction, which has high safety and low cost. At the same time, by controlling the noise level, it significantly improves the comfort of the working environment and has good economy and practicality.

[0066] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A confined space ventilation system for cement pipe hand-dug jacking construction, characterized in that: The invention comprises an original soil layer (1), a working pipe (2), a curved air duct (3), an air supply box (4), and an oxygen content detector (5). The working pipe (2) is placed in the original soil layer (1), the curved air duct (3) is installed at the top of the working pipe (2), a plurality of air supply ports are provided on the curved air duct (3), and the plurality of air supply ports are located at one side of a working area in the working pipe (2). The air supply box (4) is installed on the other side of the curved air duct (3), and the air supply end of the air supply box (4) is communicated with the inside of the curved air duct (3). The oxygen content detector (5) is installed in the working area in the working pipe (2); and the air supply box (4) is provided with a signal receiver for receiving signals sent by the oxygen content detector (5).

2. A confined space ventilation system for cement pipe hand-dug jacking construction according to claim 1, characterized in that: The plurality of air supply ports are opened on the lower surface of the curved air duct (3).

3. A confined space ventilation system for cement pipe hand-dug jacking construction according to claim 1, characterized in that: A tie belt (8) is provided inside the curved air duct (3).

4. A confined space ventilation system for cement pipe hand-dug jacking construction according to claim 1, characterized in that: A plurality of the curved air ducts (3) are provided, and the plurality of curved air ducts (3) are connected by cables.

5. The air supply and exhaust system for a confined space in cement pipe hand-dug jacking construction according to claim 1 is characterized in that: A plurality of first embedded steel plates (6) are horizontally arranged on the inner top of the working tube (2), and a strong magnetic hook (7) is provided on the lower surface of the first embedded steel plate (6); air duct hanging points (9) are evenly arranged on the outer top of the curved air duct (3), and the strong magnetic hook (7) passes through the air duct hanging points (9) and is adsorbed on the first embedded steel plate (6).

6. A confined space ventilation system for cement pipe hand-dug jacking construction according to claim 1, characterized in that: A plurality of second embedded steel plates (10) are horizontally arranged on the inner side of the working tube (2), a magnetic block (11) is arranged on the oxygen content detector (5), and the oxygen content detector (5) is magnetically attracted to the second embedded steel plates (10) through the magnetic block (11).

7. The air supply and exhaust system for a confined space in cement pipe hand-dug jacking construction according to claim 1 is characterized in that: An air supply module and a refrigeration module are provided inside the air supply box (4).

8. The air supply and exhaust system for a confined space in cement pipe hand-dug jacking construction according to claim 1 is characterized in that: The calculation formula for the height of the curved air duct (3) is: Where h represents the height of the curved duct; R represents the inner radius of the working tube; and N represents the number of workers inside the working tube.

9. The air supply and exhaust system for a confined space in cement pipe hand-dug jacking construction according to claim 1, characterized in that: The calculation formula of the cross-sectional length of the curved air duct (3) is: l=0.78πR; wherein l represents the cross-sectional length of the curved air duct; and R represents the inner radius of the working tube.

10. The air supply and exhaust system for a confined space in cement pipe hand-dug jacking construction according to claim 1, characterized in that: The calculation formula for the number of air outlets is: Where n represents the number of air outlets; N represents the number of workers inside the working tube; and d represents the aperture of the air outlet.

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