阅读说明：本技术 一种应用于降膜除尘的非均匀降膜管及单元和装置 (Non-uniform film falling pipe, unit and device applied to falling film dust removal ) 是由 余徽 刘泽坤 魏文韫 熊国栋 熊波 杨雅琪 于 2019-09-30 设计创作，主要内容包括：本发明公开了一种应用于降膜除尘的非均匀降膜管及单元和装置。上述降膜管包括圆管本体和位于圆管本体上的限流槽；限流槽底面上最低点和最高点距横截面圆边线的径向距离分别为0.3～5.9mm,0.1～1mm,限流槽的开槽角度为30～210°。上述单元包括分布板和上述非均匀降膜管；所述分布板包括顶部分布板和底部分布板。上述装置包括上述单元和导流通道；导流通道将多个单元交叉连通；底部分布板包括第二通孔；第二通孔的中心位于由相邻第一通孔组成的三角形几何中心。本发明有效降低了用水量,进而降低了循环输送水的能耗；并且通过设置限流槽,避免了过多的液膜布置；在限流槽的约束下形成稳定液膜,可承载较高气速而不容易发生雾沫夹带现象。(The invention discloses a non-uniform film falling pipe, a unit and a device applied to falling film dust removal. The falling film tube comprises a circular tube body and a flow limiting groove positioned on the circular tube body; the radial distance between the lowest point and the highest point on the bottom surface of the flow-limiting groove and the circular side line of the cross section is 0.3-5.9 mm and 0.1-1 mm respectively, and the grooving angle of the flow-limiting groove is 30-210 degrees. The unit comprises a distribution plate and the non-uniform film falling pipe; the distribution plates include a top distribution plate and a bottom distribution plate. The device comprises the unit and a flow guide channel; the guide channel connects the multiple units in a cross way; the bottom cloth plate comprises a second through hole; the center of the second through hole is positioned at the geometric center of a triangle formed by the adjacent first through holes. The invention effectively reduces the water consumption, thereby reducing the energy consumption of circularly conveying water; and excessive liquid film arrangement is avoided by arranging the flow limiting groove; form stable liquid film under the restraint of restriction groove, can bear higher air velocity and be difficult to take place the foam and carry the phenomenon secretly.)

1. The non-uniform film falling pipe applied to falling film dust removal is characterized by comprising a circular pipe body (11) and a flow limiting groove (12) positioned on the outer side surface of the circular pipe body (11);

the flow-limiting groove (12) comprises a bottom surface (1201) and a side surface (1202);

in the same cross section: the radial distances between the lowest point and the highest point on the bottom surface (1201) and the sideline of the cross-sectional circle (1101) are 0.3-5.9 mm and 0.1-1 mm respectively; the intersection point of the side line of the side surface (1202) and the side line of the cross-section circle (1101) and the center of a circle form a current-limiting groove opening angle (1203) of 30-210 degrees.

2. The non-uniform film falling pipe applied to falling film dust removal according to claim 1, wherein the simulated pipe diameter and the pipe length of the circular pipe body (11) are respectively as follows: 2-5 mm, 300-400 mm; in the same cross section: the radial distance between the lowest point on the bottom surface (1201) and the side line of the cross-sectional circle (1101) is 0.3-4.4 m; the grooving angle (1203) of the flow limiting groove is 60-120 degrees; the included angle (1204) formed by the bottom surface (1201) and the side surface (1202) is 60-120 degrees.

3. The non-uniform falling film tube applied to falling film dust removal according to claim 1 or 2, wherein the bottom surface (1201) is a plane or an arc surface.

4. The non-uniform falling film tube for falling film dust removal according to claim 3, wherein the number of the flow-limiting grooves (12) is 1 or more.

5. A non-uniform falling film dedusting unit is characterized by comprising a distribution plate and the non-uniform falling film pipe applied to falling film dedusting according to any one of claims 1-4;

the distribution plates comprise a top distribution plate (21) and a bottom distribution plate (22);

the top distribution plate (21) is provided with a plurality of first through holes (2101), and the cambered surfaces of the first through holes (2101) are matched with the cambered surface of the non-uniform falling film pipe circular body (11); the first through holes (2101) are uniformly distributed in a triangular staggered manner;

the bottom distribution plate (22) is provided with a plurality of counter bores (2201), and the counter bores (2201) are matched with the projection area of the first through hole (2101);

the distance between the top distribution plate (21) and the bottom distribution plate (22) is matched with the length of the film falling pipe; one end part of the non-uniform membrane reducing pipe is embedded into the counter bore (2201), and the other end part and the first through hole (2101) form a liquid leakage area;

the slotted surface of the flow limiting groove (12) is orthogonal to the flowing direction of the gas-phase fluid.

6. The non-uniform falling film dust removal unit according to claim 5, wherein the first through holes (2101) are uniformly distributed in the shape of a regular triangle.

7. The non-uniform falling film dust removal unit according to claim 5, wherein the first through holes (2101) are round holes.

8. The non-uniform falling film dust removal unit according to claim 7, wherein the shape of the weep area matches the cross section of the flow-restricting trough (12).

9. A non-uniform falling film dust removal device is characterized by comprising a plurality of non-uniform falling film dust removal units and flow guide channels which are stacked up and down and are according to any one of claims 5 to 8;

the guide channel is used for communicating the plurality of dust removal units;

the bottom distribution plate (22) also comprises a plurality of second through holes (2202);

the center of the second through hole (2202) is positioned at the geometric center of a triangle formed by the adjacent first through holes (2101).

10. The non-uniform falling film dust collector according to claim 9, wherein the number of said dust collecting units is 3.

Technical Field

The invention relates to the technical field of washing and dust removal, in particular to a non-uniform film falling pipe, a unit and a device applied to falling film dust removal.

Background

In recent years, with the rapid increase of national economy, society has attracted more and more attention to the problem of atmospheric environment. A large part of dust-containing particles in the atmosphere come from metallurgical steelmaking electric furnaces and raw coal-fired boilers, and tail gas pollutants discharged by the furnaces cause great harm to the surrounding environment. The nation sets increasingly severe emission standards for the emission of industrial tail gas, and the latest emission standard of atmospheric pollutants for thermal power plants (GB13223-2011) jointly issued by the national ministry of environmental protection and the national Central office of quality supervision, inspection and quarantine in 7/18 th 2011 indicates that for coal-fired power plants, the concentration of particulate matters in the tail gas is 50mg Nm^-3(emission standard of atmospheric pollutants of thermal power plant, GB13223-2003) to 30mg Nm^-3. Compared with standards before and after revision, the regulation on the emission quality of industrial tail gas is stricter, which puts higher requirements on the tail gas dust removal technology.

Industrial tail gas dust removal can be divided into an electric dust remover, a filter dust remover, a washing dust remover and the like according to a trapping mechanism. The electrostatic precipitator utilizes electrostatic force to separate dust particles from air flow, and is usually classified according to plate type and tube type, and is characterized by small air flow resistance, high dust removal efficiency up to more than 99%, high investment and large floor area. Dust particles are separated and trapped when dust-containing gas in the filter dust remover flows through a filter material, and the dust remover adopts two modes of internal filtering and surface filtering, wherein the dust removing efficiency is generally 90-99 percent, but the dust remover is not suitable for high-temperature dust-containing gas.

The principle of washing and dedusting is that the liquid is used for washing the dust-containing gas, so that dust particles are captured by colliding with liquid drops or a liquid film, the dedusting efficiency is 80% -95%, but the method has low economy and consumes a large amount of energy on liquid phase circulation; on the other hand, the device using the liquid film type dust removal is poor in capability of stabilizing the liquid film due to the fact that the liquid film is thin, so that entrainment is easily generated in the device, and dust removal efficiency is affected.

Disclosure of Invention

The invention provides a non-uniform film falling pipe applied to falling film dust removal, which mainly solves the technical problems that the traditional film falling dust removal device is high in energy consumption and poor in economical efficiency, and entrainment is easy to generate.

The invention also provides a dust removal unit matched with the non-uniform falling film pipe.

The invention also provides a non-uniform falling film dust removal device comprising a plurality of dust removal units.

In order to solve the technical problems, the invention adopts the following specific technical scheme:

the non-uniform film falling pipe applied to falling film dust removal comprises a circular pipe body and a flow limiting groove positioned on the outer side surface of the circular pipe body; the flow-limiting groove comprises a bottom surface and a side surface; in the same cross section, the radial distances between the lowest point and the highest point on the bottom surface and the circular borderline of the cross section are respectively 0.3-5.9 mm and 0.1-1 mm; the slotting angle (hereafter referred to as slotting angle) of the current-limiting slot formed by the intersection point of the side sideline and the section circular sideline and the circle center is 30-210 degrees.

The simulated pipe diameter of the circular pipe body is the diameter of the circular pipe under the condition that the flow limiting groove is not arranged.

The cross-section circle is a circumference determined by the outermost edge line of the circular tube body in the cross section, and the circumference is a complete circle.

The radial distance between the lowest point and the highest point on the bottom surface of the flow-limiting groove and the circular boundary line of the cross section is related to the shape of the bottom surface. When the bottom surface of the flow-limiting groove is an arc surface matched with the circular pipe body, the radial distances between the lowest point and the highest point on the bottom surface and the cross-section circular side line are equal, and the radial distances are the depth of the flow-limiting groove.

The current-limiting groove notching angle in the invention is related to the Reynolds number and the separation angle of gas flowing around the cylinder. The specific design basis is as follows:

when gas-phase fluid flows across the array cylinder, pressure difference is generated in the boundary layer of the surface of the cylinder, boundary layer separation phenomenon occurs between the gas phase and the wall surface of the cylinder, and the separation position of the boundary layer is a separation point. The position of the separation point and the cylinder show a corresponding relation related to Reynolds number. The higher the Reynolds number is, the more downstream the gas-phase fluid is located at a position where the boundary layer separation of the gas-phase fluid from the cylindrical wall surface occurs. When 7 is<Re_D<When 200, the process:

in the formula [ theta ]_sIs the separation angle, °; re_DIs the cylinder apparent Reynolds number; u is the main flow velocity of the continuous phase fluid, m.s^-1；D_cIs the diameter of the cylinder, m; v is the kinematic viscosity of the continuous phase fluid, m²·s^-1。

When the cylinder is pure liquid column, dusty gas bypasses the cylinder and climbs under the low reynolds number and flows under the motion, can divide into 3 regions with the cylinder surface according to the ability that the cylinder caught the particulate matter: windward area, escape area and leeward area. In the invention, the flow-limiting groove is arranged at the windward area, namely, towards the flowing direction of the liquid phase fluid, and the flow-limiting groove is specifically arranged in the direction of the flow-limiting groove in the subsequent dust removal unit. The particles are mainly captured by the cylinder in the windward area, and the escape area has less removal of the particles; the leeward area is positioned behind the boundary layer separation point of the gas-phase fluid and the cylindrical surface, the gas-phase fluid and the cylindrical surface have boundary layer separation, and particulate matters are not captured any more.

Therefore, the grooving angle of the non-uniform falling film pipe should correspond to the separation angle, but it is not necessarily exactly the same as the separation angle, because when the grooving angle is larger, although the particle removal efficiency is increased, the liquid amount required for stabilizing the falling film is increased, resulting in increased water delivery energy consumption and reduced equipment operation economy. Therefore, the grooving angle needs to consider the comprehensive judgment of the particulate matter removal efficiency and the water delivery energy consumption at the same time. Therefore, in the invention, the slotting angle of the flow-limiting groove formed by the intersection point of the side surface of the flow-limiting groove and the circular side line of the cross section and the circle center is set to be 30-210 degrees.

When the diameter of the opening of the distribution plate is the same as the simulated diameter of the non-uniform film falling pipe, the liquid leakage area is matched with the cross section of the non-uniform film falling groove, the outer surface of a liquid film at an inlet of the distribution plate is basically the same as the outer edge surface of the flow limiting groove, the flow rate of the liquid film is slowly increased under the action of gravity, the film thickness is slightly reduced, the fluctuation of the liquid film is slowly increased, when the liquid falls to a certain height, the gravity borne by the liquid in the film is balanced with the shearing force of the wall surface to the liquid, the flow rate is kept unchanged, the thickness of the liquid film is not changed any more, the falling height:

in the formula Q_ml0Is the liquid mass flow of a single falling film pipe, kg.s^-1；u_AIs the average flow velocity of the liquid in the liquid film, m.s^-1；A_lIs a cross-sectional area of liquid flow, m²。

The average velocity in the liquid film can be solved by the following formula:

wherein g is the acceleration of gravity, m.s²(ii) a Delta is the thickness of the liquid film, m; rho_lIs liquid density, kg.m³；μ_lLiquid viscosity, pas. When the mass flow of a single falling film pipe is known, the average flow velocity of the liquid film and the maximum flow velocity in the film when the liquid film vertically flows downwards can be obtained through the formula. If the thickness of a liquid film in the falling film flowing time slot is the same, the water consumption under the working condition of a single cylinder is in direct proportion to the slotting angle, as shown in the following formula:

and analyzing and calculating the lowest operation energy consumption of the film-reducing pipes with different grooving angles, wherein the gas-phase energy consumption is gas-phase fluid conveying pressure drop, and the liquid-phase energy consumption is circulating water conveying energy consumption. When the grooving angle range is known, the water consumption under the working condition of a single cylinder can be solved and calculated through the formula (5), and the operation energy consumption can be solved through the following formula:

aQ_vl＝Q_vl0n_all (7)

H_m＝az₀ (8)

w_l＝H_mQ_vlρ_lg (9)

wherein A is a gas phase flow cross-sectional area, m²；h₁Is the effective falling film height of the falling film tube, m; n is_allThe total number of non-uniform film reducing pipes required when the dust removal tower reaches 80% of mass removal rate under different slotting angles of the device is obtained; a is the number of device layers; q_vlAmount of circulating water required for a single layer of the device, m³·s^-1； Q_vl0M is water quantity for single non-uniform falling film pipe³·s^-1；H_mM is the total height of the device; w is a_lThe lowest energy consumption for conveying the liquid phase is W. For gas phase transport pressure drop, the gas phase flow rate is low, so thatNeglecting the energy consumption generated by dynamic wind pressure, the minimum transmission energy consumption can be solved by the following formula:

w_g＝Δp_gQ_vg (10)

in the formula w_gThe lowest energy consumption for conveying the gas phase is W; Δ p_gThe total pressure drop of the gas path is Pa; q_vgFor the gas processing amount under the operation task, m³·s^-1。

The radial distance between the lowest point and the highest point on the bottom surface of the flow-limiting groove and the circular boundary line of the cross section is related to the stability of the liquid film and the energy consumption of liquid transportation. When the distance between the lowest point and the highest point on the bottom surface of the flow-limiting groove and the distance between the cross-section circular line and the cross-section circular line are relatively low in the radial direction, the liquid film fluctuation caused by falling film flowing can prevent the liquid from being completely limited in the flow-limiting groove; the radial distance between the lowest point and the highest point on the bottom surface of the flow-limiting groove and the circular side line of the cross section is too large, so that the liquid flow is increased, and the operation energy consumption is high.

According to the invention, liquid phase fluid flows into the flow-limiting groove from one end to the other end and flows out to form a liquid film, and the liquid film formed in the flow-limiting groove effectively reduces the water consumption and the energy consumption of circularly conveying water compared with the traditional full-covering liquid film on the outer surface of the falling film pipe; in addition, the opening surface of the flow limiting groove faces the windward area, so that the position advantage is fully utilized, and excessive liquid film arrangement is avoided; meanwhile, the liquid film is not easy to generate entrainment under the protection of the flow limiting groove, and the formed liquid film is very stable.

From the above principle and equations (3) to (10), the following preferred parameters can be derived.

As a preferred scheme of the present invention, the simulated pipe diameter and the pipe length of the circular pipe body are respectively: 2-5 mm, 200-500 mm.

As a preferred aspect of the present invention, on the same cross section: the radial distances between the lowest point and the highest point on the bottom surface and the cross-section circular sideline are respectively 0.3-5.9 mm and 0.1-1 mm; the slotting angle of the flow-limiting groove formed by the intersection point of the side top sideline and the section circle and the circle center is 30-210 degrees; the bottom surface and the side included angle of 30 ~ 150.

As a further preferable scheme of the invention, the simulated pipe diameter and the pipe length of the circular pipe body are respectively 2-5 mm and 300-400 mm.

As a preferred aspect of the present invention, on the same cross section: the radial distances between the lowest point and the highest point on the bottom surface and the cross-section circular sideline are respectively 0.3-4.4 mm and 0.1-1 mm; the slotting angle of the flow-limiting groove formed by the intersection point of the side surface and the section circular sideline and the circle center is 60-120 degrees; the bottom surface and the side included angle of 60 ~ 120.

In order to match the use of the non-uniform film falling pipe applied to falling film dust removal, the invention also provides:

a non-uniform falling film dust removal unit comprises a distribution plate and the non-uniform falling film tube; the distribution plates comprise a top distribution plate and a bottom distribution plate; the top distribution plate is provided with a plurality of first through holes, and the cambered surfaces of the first through holes are matched with the cambered surface of the non-uniform falling film pipe circular body; the first through holes are uniformly distributed in a triangular staggered manner; the bottom distribution plate is provided with a plurality of counter bores, and the counter bores are matched with the projection area of the first through holes; the distance between the top distribution plate and the bottom distribution plate is matched with the length of the film falling pipe; one end part of the non-uniform membrane reducing pipe penetrates through the first through hole and is embedded into the counter bore, and the other end part and the first through hole form a liquid leakage area; the open slot of the flow-limiting slot faces to the windward area of the gas phase fluid.

The top distribution plate is provided with a plurality of first through holes, the cambered surfaces of the first through holes are matched with the cambered surface of a circular tube body of the non-uniform falling film tube, when one end of the non-uniform falling film tube is embedded into the first through hole, the cambered surface of the circular tube body is matched with the through holes, and the cross section of the flow limiting groove on the non-uniform falling film tube and the through holes form a liquid leakage area; the first through holes are uniformly distributed in a triangular staggered manner, so that the flowing distance of gas-phase fluid is effectively prolonged, the mass transfer efficiency is increased, and the space is saved. The bottom distribution plate is provided with a counter bore, when liquid flows to the counter bore and is fully collected, the liquid in the counter bore overflows, and the liquid distribution plate plays a role in one aspect

The non-uniform membrane falling pipe is fixed, and on the other hand, the liquid collecting effect is achieved. The area of the liquid leakage area is related to the resistance loss of the dry plate of the distribution plate where the liquid leakage area is located, when liquid flows down from the upper layer through the non-uniform film falling pipe, a liquid layer is formed on the distribution plate on the lower layer, when the liquid flows down through the liquid leakage area to form a liquid film, the liquid is subjected to the pressure of the liquid layer on the liquid, the gravity of the liquid and the resistance of the distribution plate to the liquid caused by the liquid leakage area, and when the area of the liquid leakage area is changed, the resistance of the distribution plate to the liquid, the height of the liquid layer on the distribution plate and the thickness of the liquid film formed by the. The side surface of the bottom distribution plate is provided with an overflow groove to prevent the thickness of the liquid collecting layer on the bottom distribution plate from continuously thickening to interfere the liquid film to capture particles in the gas phase.

As the preferred scheme of the invention, the first through holes are uniformly distributed in the shape of a regular triangle, and the arrangement mode is more favorable for improving the dust removal efficiency and the space utilization rate.

As a preferable scheme of the invention, the first through hole is a round hole, and the structure is matched with the non-uniform falling film pipe.

As a preferable scheme of the invention, the liquid leakage area is matched with the cross section of the non-uniform falling film tube flow limiting groove, so that liquid phase fluid can conveniently enter the flow limiting groove to form a stable liquid film.

In addition, the invention provides the following for further improving the dust removal efficiency:

a non-uniform falling film dust removal device comprises a plurality of non-uniform falling film dust removal units stacked up and down and a flow guide channel; the guide channel is used for communicating the plurality of dust removal units; the bottom cloth plate also comprises a plurality of second through holes; the center of the second through hole is positioned at the geometric center of the triangle formed by the adjacent first through holes.

When a plurality of dust removing units are piled up and down for use, the bottom distribution plate is provided with a plurality of second through holes and a plurality of counter bores, the purpose is to take the plate as a flow distribution plate and also take the plate as a support plate, the structure of the device is simplified, and the technical effect of 'one plate is dual-purpose, and two plates are integrated' is achieved.

As the preferred scheme of the invention, the number of the dust removal units is 3, so that reasonable energy consumption and better dust removal effect can be realized.

When a plurality of dust removal units are arranged, the openings of the flow limiting grooves of the non-uniform film falling pipes in the adjacent upper and lower layers of dust removal units are opposite or back to each other.

Compared with the prior art, the invention has the beneficial effects that:

in the invention, liquid phase fluid flows into the flow limiting groove from one end to the other end and flows out to form a liquid film, so that the liquid film formed in the groove does not need to be arranged on the outer surface of the whole falling film pipe compared with the traditional liquid film fully covered on the outer surface of the falling film pipe, the water consumption is effectively reduced, and the energy consumption of circularly conveying water is further reduced; in addition, the opening surface of the flow limiting groove is orthogonal to the flowing direction of the gas-phase fluid, the key position is fully utilized, relevant parameters are determined through the research of a fluid mechanics mechanism, and excessive liquid film arrangement is avoided; meanwhile, the liquid film is not easy to generate entrainment under the protection of the flow limiting groove with a concave structure, and the formed liquid film is very stable.

The top distribution plate is provided with the first through holes which are uniformly distributed in a triangular staggered manner, so that the flowing distance of gas-phase fluid is effectively prolonged, the mass transfer efficiency is increased, and the advantage of saving space is achieved. The bottom distributing plate is provided with a counter bore, when liquid flows to the counter bore and is collected fully, the liquid in the counter bore overflows, on the one hand, the effect of the fixed non-uniform film falling pipe is achieved, and on the other hand, the effect of liquid collection is achieved. The area of the liquid leakage area is related to the resistance loss of the dry plate of the distribution plate where the liquid leakage area is located, when liquid flows down from the upper layer through the non-uniform film falling pipe, a liquid layer is formed on the distribution plate on the lower layer, when the liquid flows down through the liquid leakage area to form a liquid film, the liquid is subjected to the pressure of the liquid layer on the liquid, the gravity of the liquid and the resistance of the distribution plate to the liquid caused by the liquid leakage area, and when the area of the liquid leakage area is changed, the resistance of the distribution plate to the liquid, the height of the liquid layer on the distribution plate and the thickness of the liquid film formed by the. The side surface of the bottom distribution plate is provided with an overflow groove to prevent the thickness of the liquid collecting layer on the bottom distribution plate from continuously thickening to interfere the liquid film to capture particles in the gas phase.

When a plurality of dust removing units are piled up and down for use, the bottom distribution plate is provided with a plurality of second through holes and a plurality of counter bores, so that the purpose is to use the plate as a flow distribution plate and also as a support plate, the structure of the device is simplified, and the technical effect of 'one plate is dual-purpose, and two plates are integrated' is achieved.

Drawings

FIG. 1 is a schematic structural diagram of a non-uniform membrane-reducing tube.

Fig. 2 is a schematic cross-sectional view taken along a line a in fig. 1.

Fig. 3 is a schematic cross-sectional structure diagram of a plurality of flow-limiting grooves.

Fig. 4 is a schematic perspective view of a non-uniform membrane-dropping tube.

FIG. 5 is a schematic front view of a dust removal unit with two non-uniform film falling tubes.

FIG. 6 is a schematic top view of a distributor plate.

Fig. 7 is a schematic view of a part of the enlarged structure at B in fig. 6.

Fig. 8 is a schematic perspective view of the dust removing unit.

Fig. 9 is a partially enlarged structural view of a portion C in fig. 8.

Fig. 10 is a partially enlarged view of the structure at D in fig. 8.

Fig. 11 is a schematic perspective view of a dust removing device having a plurality of dust removing units.

Fig. 12 is a schematic view of a part of an enlarged structure at E in fig. 11.

Fig. 13 is a schematic front view of a dust removing device having a plurality of dust removing units.

FIG. 14 is a schematic perspective view of a dust removing device with a plurality of dust removing units, wherein the dust removing device is covered with non-uniform film falling pipes.

In the figure:

1. a non-uniform membrane-reducing tube;

11. a circular tube body; 1101. a cross-sectional circle;

12. a flow limiting groove; 1201. a bottom surface; 1202. a side surface; 1203. grooving angle; 1204. an included angle;

2. a distribution plate;

21. a top distribution plate; 2101. a first through hole;

22. a bottom distribution plate; 2201. a counter bore; 2202. a second through hole;

3. a flow guide channel.

Detailed description of the preferred embodiments

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