A fast dust removal device and method suitable for tunnel blasting

Abstract

The present invention discloses a rapid dust removal device and method suitable for tunnel blasting, the device comprises a container body arranged in a blasthole, the container body is a cylindrical container with an upper opening and a bottom closing, hydrazine hydrate is arranged in the middle of the inner cavity of the container body, hydrogen peroxide is evenly arranged on the upper and lower sides of the hydrazine hydrate, hydrazine hydrate and hydrogen peroxide are respectively wrapped by a solution bag body of plastic material, and the two are separated by a crushed stone filler. The present invention utilizes the characteristic that hydrogen peroxide and hydrazine hydrate react quickly to produce water vapor and nitrogen, so that water molecules can quickly contact with dust, so as to achieve the effect of rapid dust removal; the chemical reaction adopted does not produce harmful gases, and has the characteristics of being green and safe.

Description

Technical Field

[0001] The invention relates to the technical field of rock mass blasting, and in particular to a rapid dust removal device and method suitable for tunnel blasting. Background Art

[0002] After tunnel blasting, the dust and harmful gas content in the tunnel seriously exceeded the standard within a certain period of time. The existence of this problem not only seriously affects the safety of tunnel construction, but also causes serious damage to the health of construction workers. In addition, since the wind circulation in the tunnel cannot make the dust escape and settle quickly, and waiting for the dust to settle naturally will delay the construction period and increase the construction cost. Therefore, it is necessary to use blasting dust removal equipment to reduce the dust.

[0003] Chinese patent CN212701181U discloses a tunnel dust removal device. Although this device can remove dust in the tunnel, the terrain in the tunnel is complex and the cart cannot move smoothly, resulting in low dust removal efficiency. In addition, Chinese patent CN101046366A discloses an environmental protection engineering hydraulic blasting hole and its blasting method. Although this method can improve the blasting utilization rate, it has low efficiency in dust degradation.

[0004] Therefore, there is an urgent need for a rapid dust removal device and method suitable for tunnel blasting that has high dust reduction efficiency and is easy to implement. Summary of the invention

[0005] In view of the problem that dust disappears slowly after blasting, the present invention proposes a rapid dust removal device and method suitable for tunnel blasting, which utilizes the characteristic that hydrogen peroxide reacts with hydrazine hydrate to quickly produce water vapor and nitrogen, so that water molecules can quickly contact with dust, thereby achieving the effect of rapid dust removal.

[0006] To achieve the above-mentioned purpose, the present invention is a fast dust removal device suitable for tunnel blasting, which is special in that it includes a container body arranged in a blasthole, the container body is a cylindrical container with an open top and a closed bottom, hydrazine hydrate is arranged in the middle of the inner cavity of the container body, hydrogen peroxide is evenly arranged on the upper and lower sides of the hydrazine hydrate, the hydrazine hydrate and hydrogen peroxide are respectively wrapped by solution bags made of plastic material, and the two are separated by crushed stone filling material.

[0007] Furthermore, the container body is arranged at the bottom of the blasthole, and the top is separated from the detonator and explosive in the blasthole by a water bag. The water bag is installed to prevent the high temperature generated by the explosion of the explosive from decomposing the hydrogen peroxide and causing incomplete reaction.

[0008] Furthermore, the outer surface of the container body is wrapped with iron sheet, and the iron sheet contacts the inner wall of the blast hole. Since cracks appear in the rock after blasting, the liquid is prevented from being lost due to the cracks. Placing the iron sheet can enhance the effect of the reaction and reduce the loss of effective substances.

[0009] Furthermore, the mass ratio of hydrazine hydrate to hydrogen peroxide is 25:34.

[0010] Furthermore, the length of the container body is 30 to 50 cm.

[0011] Based on the above device, the present invention also proposes a rapid dust removal method suitable for tunnel blasting, the method comprising the following steps:

[0012] 1) Determine the required mass of hydrogen peroxide and hydrazine hydrate according to the tunnel section excavation parameters;

[0013] 2) Drill holes according to the blasthole arrangement;

[0014] 3) placing the quick dust removal device suitable for tunnel blasting at the bottom of each blast hole, and placing a water bag, a detonator, explosives and gun mud in sequence above the quick dust removal device suitable for tunnel blasting;

[0015] 4) According to the blasting process, the groove holes are blasted first, followed by the auxiliary holes, and finally the peripheral holes to ensure the blasting effect. The peripheral holes explode to form water mist to accelerate dust removal.

[0016] Preferably, the method for determining the required content of hydrogen peroxide and hydrazine hydrate according to the tunnel section excavation parameters in step 1) is: calculating the volume of water required to be produced by the reaction in a single blasthole According to Calculate the masses of hydrazine hydrate and hydrogen peroxide needed.

[0017] Preferably, the volume of water required to be produced by the reaction in the single blasthole is The calculation method is:

[0018]

[0019] In the formula, is the volume of water required for the reaction in a single blasthole, η is the dust content per unit volume after blasting, is the excavation depth of a single blast, s i is the cross-sectional area of ​​excavation in a single blasting. is the number of blastholes equipped with rapid dust removal devices suitable for tunnel blasting, λ is the uncoupling coefficient of blasthole charge, Γ c This is the correction factor for the water molecules produced by the reaction to capture dust particles by inertia.

[0020] Preferably, the volume of water required to be produced by the reaction in the single blasthole is The mass relationship with hydrazine hydrate and hydrogen peroxide is:

[0021]

[0022] In the formula, Respectively represent the masses of hydrazine hydrate and hydrogen peroxide.

[0023] Preferably, the depth of the blasthole when drilling the blasthole in step 2) satisfies: the depth of the blasthole = the conventional blasthole depth + the length of the rapid dust removal device suitable for tunnel blasting.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. The present invention utilizes the characteristic that hydrogen peroxide reacts with hydrazine hydrate to quickly generate water vapor and nitrogen, so that water molecules can quickly contact with dust, thereby achieving the effect of rapid dust removal.

[0026] 2. The present invention takes into account that after blasting, cracks may appear in the rock. To prevent the loss of liquid due to the cracks, the iron sheet can be provided to enhance the effect of the reaction and reduce the loss of effective substances.

[0027] 3. The water bag installed above the device of the present invention can prevent the high temperature generated by the explosion of explosives from decomposing hydrogen peroxide and causing incomplete reaction.

[0028] 4. The chemical reaction adopted by the method of the present invention will not produce harmful gases and is green and safe. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The present invention is a schematic structural diagram of a rapid dust removal device suitable for tunnel blasting installed in a blasthole.

[0030] Figure 2 The present invention is a flow chart of a rapid dust removal method suitable for tunnel blasting.

[0031] Figure 3 This is the layout diagram of the smooth blasting holes.

[0032] In the figure, there are a container body 1, hydrazine hydrate 2, hydrogen peroxide 3, crushed stone filler 4, iron sheet 5, blast hole 6, water bag 7, detonator 8, explosive 9, and taphole mud 10. DETAILED DESCRIPTION

[0033] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0034] like Figure 1As shown, the present invention proposes a rapid dust removal device suitable for tunnel blasting, comprising a container body 1 arranged in a blasthole 6, the container body 1 is a cylindrical container with an upper opening and a bottom closed, a hydrazine hydrate 2 is arranged in the middle of the inner cavity of the container body 1, and hydrogen peroxide 3 is evenly arranged on the upper and lower sides of the hydrazine hydrate 2, the hydrazine hydrate 2 and the hydrogen peroxide 3 are respectively wrapped by a solution bag body of plastic material, and the two are separated by a crushed stone filler 4.

[0035] The outer surface of the container body 1 is wrapped with an iron sheet 5, which contacts the inner wall of the blast hole 6. The container body 1 is arranged at the bottom of the blast hole 6, with a length of 30 to 50 cm, and the top is separated from the detonator 8 and the explosive 9 in the blast hole 6 by a water bag 7. The water bag is installed to prevent the high temperature generated by the explosion of the explosive from decomposing the hydrogen peroxide and causing incomplete reaction.

[0036] The container body 1 is made of plastic material, and the hydrazine hydrate 2 and the hydrogen peroxide 3 are sealed with a solution bag, and the solution bags are made of plastic material and placed in a corresponding order in the container body 1. Sharp gravel is filled between adjacent bags to ensure that the solution bags can be broken by high pressure, so that the two can react chemically.

[0037] The order of loading the container is: first, fill the hydrogen peroxide solution, then fill 1cm to 2cm with gravel, then fill the hydrazine hydrate solution bag, then fill 1cm to 2cm with gravel, then fill the hydrogen peroxide solution bag. Finally, seal the container side of the opening with a water bag.

[0038] The reaction mechanism is: after hydrogen peroxide and hydrazine hydrate react, nitrogen and water are generated. Due to the violent reaction and heat release, water is generated in the form of water vapor, and the narrow space of the blast hole 6 causes the water vapor to be carried out by the nitrogen and combined with the dust, accelerating the dust to fall. The dust removal effect is achieved. Since the mass ratio of the reaction of hydrazine hydrate and hydrogen peroxide in the chemical reaction equation is 1:2, hydrazine hydrate 2 and hydrogen peroxide 3 are divided equally to ensure that the hydrazine hydrate solution reacts completely, generating enough water and nitrogen, and the formed water mist can attach to dust particles for dust removal.

[0039] Based on the above device, the present invention proposes a rapid dust removal method suitable for tunnel blasting, such as Figure 2 As shown, the following steps are included:

[0040] 1) Determine the required mass of hydrogen peroxide and hydrazine hydrate according to the tunnel section excavation parameters:

[0041] The tunnel section excavation area in this embodiment is: 70m 2 The excavation depth is 3m, and smooth blasting is used. According to the calculation formula and parameters, the required content of hydrogen peroxide and hydrazine hydrate is determined:

[0042]

[0043] The volume of water required to produce the reaction in a single blasthole

[0044] η: The dust content per unit volume after blasting (measured using conventional explosion-proof dust sampling instruments): 360 mg / m 3

[0045] The excavation depth for a single blast is 3m;

[0046] s i :Single blasting excavation cross-sectional area, take 70m 2 ;

[0047] The number of blastholes for installing this device is 20;

[0048] λ: uncoupling coefficient of blast hole charge, taken as 0.8;

[0049] Γ c : The correction factor for the water molecules produced by the reaction to capture dust particles by inertia is taken as 0.3.

[0050] Bring the above parameter values ​​into The calculation formula is Therefore, according to The required mass of hydrogen peroxide and hydrazine hydrate is calculated as follows:

[0051] Calculate the formula based on the chemical reaction equation

[0052] N2H4·H2O+2H2O2=5H2O+N2↑

[0053] The above formula calculates that the required H2O content in a single blasthole is 1.4175L, and 1.5L is taken.

[0054] Therefore, the content of hydrazine hydrate and hydrogen peroxide is calculated according to the mass conservation principle of the chemical reaction equation:

[0055]

[0056] 2) If Figure 3 As shown, according to the arrangement of blastholes 6, the blastholes are drilled. The depth of blasthole drilling = conventional blasthole depth + device length, wherein the conventional blasthole depth is generally 1m, and the length of this device is 30cm. Therefore, the blasthole depth is 1.3m.

[0057] 3) A rapid dust removal device suitable for tunnel blasting is placed at the bottom of each blast hole, and a water bag 7, a detonator 8, explosives 9 and gun mud 10 are placed in sequence above the rapid dust removal device suitable for tunnel blasting; wherein the container device and the inner wall of the blast hole 6 are wrapped with a layer of iron sheet 5 to prevent the solution from flowing into the rock mass through the cracks after blasting, resulting in low reaction efficiency.

[0058] 4) According to the blasting process, the groove holes are blasted first, followed by the auxiliary holes, and finally the peripheral holes to ensure the blasting effect. The peripheral holes explode to form water mist to accelerate dust removal.

[0059] The FCC-25 explosion-proof dust sampling instrument was used to collect dust concentration in the face blasting project without any dust reduction measures under the same conditions. The collection locations were 10m, 20m, and 30m away from the face. According to the collected data, the dust concentration at 5m away from the blasting area was 328-397mg / m 3 The dust concentration at 10m is between 159 and 193mg / m 3 The dust concentration at 15m is between 83 and 105mg / m 3 It can be seen that the dust concentration in tunnel blasting will gradually decrease with the distance, and the dust concentration decays slowly when the blasting is more than 15m away.

[0060] Table 1 Comparison of dust removal effects in face blasting projects

[0061]

[0062] Compared with the new technology of explosion water mist dust reduction, the dust concentration obtained by the same method is: the dust concentration at 5m away from the gun area is 122mg / m 3 , the dust concentration at 10m is 80mg / m 3 , the dust concentration at 15m is 41mg / m 3 . Through calculation, it can be concluded that the maximum blasting dust concentration is reduced by 65%, which is a very obvious dust reduction effect for tunnel blasting. The amount of blasting dust without any dust reduction measures is doubled compared to the amount of smoke and dust after this measure is adopted. The dust reduction effect of explosion water mist is also very obvious when observed with the naked eye on site.

[0063] Although the preferred embodiments of the present invention have been described above in conjunction with the accompanying drawings, the present invention is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms of specific changes without departing from the scope of protection of the purpose of the present invention and the claims, which all fall within the scope of protection of the present invention.

Claims

1. A rapid dust removal device suitable for tunnel blasting, characterized in that: The invention comprises a container body (1) arranged in a blasthole (6), wherein the container body (1) is a cylindrical container with an upper opening and a lower closing, wherein a hydrazine hydrate (2) is arranged in the middle of the inner cavity of the container body (1), and hydrogen peroxide (3) is evenly arranged on the upper and lower sides of the hydrazine hydrate (2), wherein the hydrazine hydrate (2) and the hydrogen peroxide (3) are respectively wrapped by a solution bag body made of a plastic material, and the two are separated by a crushed stone filler (4); the container body (1) is arranged at the bottom of the blasthole (6), and the top is separated from the detonator (8) and the explosive (9) in the blasthole (6) by a water bag (7); the outer surface of the container body (1) is wrapped with an iron sheet (5), and the iron sheet (5) is in contact with the inner wall of the blasthole (6); the mass ratio of the hydrazine hydrate (2) to the hydrogen peroxide (3) is 25:34; The method for determining the required content of hydrogen peroxide (3) and hydrazine hydrate (2) according to the tunnel section excavation parameters is as follows: Calculate the volume of water required to be produced by the reaction in a single blasthole (6) According to the volume of water Calculate the mass of water According to The mass of hydrazine hydrate (2) and hydrogen peroxide (3) required for calculation; the mass of water required to be produced by the reaction in the single blast hole (6) The mass relationship with hydrazine hydrate (2) and hydrogen peroxide (3) is: In the formula, Respectively represent the masses of hydrazine hydrate (2) and hydrogen peroxide (3).

2. The rapid dust removal device suitable for tunnel blasting according to claim 1 is characterized in that: The length of the container body (1) is 30 to 50 cm.

3. A rapid dust removal method suitable for tunnel blasting, the method is implemented based on a rapid dust removal device suitable for tunnel blasting according to claim 1 or 2, characterized in that: The method comprises the following steps: 1) Determine the required mass of hydrogen peroxide (3) and hydrazine hydrate (2) according to tunnel section excavation parameters; 2) drilling the blast holes according to the arrangement of the blast holes (6); 3) placing the quick dust removal device suitable for tunnel blasting at the bottom of each blast hole, and placing a water bag (7), a detonator (8), explosives (9) and blasting mud (10) in sequence above the quick dust removal device suitable for tunnel blasting; 4) According to the blasting process, the groove holes are blasted first, followed by the auxiliary holes, and finally the peripheral holes to ensure the blasting effect. The peripheral holes explode to form water mist to accelerate dust removal.

4. A rapid dust removal method suitable for tunnel blasting according to claim 3, characterized in that: The volume of water required to be produced by the reaction in the single blasthole (6) The calculation method is: In the formula, is the volume of water required for the reaction in a single blasthole, η is the dust content per unit volume after blasting, is the excavation depth of a single blast, s i is the cross-sectional area of ​​excavation in a single blasting. is the number of blastholes equipped with rapid dust removal devices suitable for tunnel blasting, λ is the uncoupling coefficient of blasthole charge, Γ c This is the correction factor for the water molecules produced by the reaction to capture dust particles by inertia.

5. A rapid dust removal method suitable for tunnel blasting according to claim 3, characterized in that: In the step 2), the depth of the blasthole drilling satisfies: the depth of the blasthole drilling = the conventional blasthole depth + the length of the rapid dust removal device suitable for tunnel blasting.

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