CN220460672U

CN220460672U - Continuous hydrolysis kettle for production of nitro guanidine

Info

Publication number: CN220460672U
Application number: CN202321932957.0U
Authority: CN
Inventors: 吴根龙; 吴全生; 吴全龙; 周利成; 李建军; 祁建军; 金跃新; 张根宝; 杨亚明; 黄学东; 钱卫兵; 陈德元; 刘萍; 陈雅新; 刘长明; 王松; 杜卫刚; 杨勇
Original assignee: Ningxia Soochow Agrochemical Co ltd
Current assignee: Ningxia Soochow Agrochemical Co ltd
Priority date: 2023-07-20
Filing date: 2023-07-20
Publication date: 2024-02-09
Anticipated expiration: 2033-07-20

Abstract

The application discloses a be used for continuous hydrolysis kettle of nitro guanidine production, the jar body lateral wall of this equipment is provided with the intermediate layer, coiler and display controller, display controller real-time supervision jar is interior temperature and the concentration of solution of hydrolysising, inject steam through the steam injection pipe and promote jar internal temperature, condensate water inlet tube water injection reduces jar internal temperature, the unnecessary cold and heat exchange medium of gaseous phase discharge pipe discharge, make new medium get into and continue to carry out the heating up and cooling to jar body and handle, guarantee nitro guanidine can be under constant temperature continuous hydrolysis, through the control valve on control inlet pipe and the water injection pipe, make nitro guanidine can constantly hydrolyze under certain temperature reach the nitro guanidine hydrolysis solution of required concentration, use display controller real-time supervision to adjust the concentration of solution of hydrolysising and the temperature in the jar, thereby reduce continuous hydrolysis kettle internal temperature and hydrolysis solution concentration control degree of difficulty, the error that exists in the nitro guanidine hydrolysis process, the influence of temperature to hydrolysis reaction has been reduced.

Description

Continuous hydrolysis kettle for production of nitro guanidine

Technical Field

The application relates to the field of production of nitro guanidine, in particular to a continuous hydrolysis kettle for production of nitro guanidine.

Background

The hydrolysis kettle is simply that various substances are stirred and mixed in the hydrolysis kettle to generate needed products after hydrolysis reaction, in the hydrolysis reaction process, certain temperature and pressure are needed, most of the hydrolysis kettles are pressure vessels and are provided with heating devices, the whole hydrolysis kettles are made of metal materials, and in order to ensure that the hydrolysis kettle can work with high efficiency, a continuous hydrolysis kettle is needed. The control difficulty of the temperature and the hydrolysis concentration in the existing continuous hydrolysis kettle is larger, errors exist in the hydrolysis process, the efficiency of the hydrolysis reaction is affected, and the continuous hydrolysis kettle for the production of the nitro guanidine is provided for solving the problems.

Disclosure of Invention

The utility model provides a be used for continuous hydrolysis kettle of nitro guanidine production, the jar body lateral wall of this equipment is provided with the intermediate layer, coiler and display controller, display controller real-time monitoring is in jar temperature and the concentration of hydrolysis solution, inject steam through the steam injection pipe and promote jar internal temperature, condensate water inlet tube water injection reduces jar internal temperature, the unnecessary cold and heat exchange medium of gaseous phase discharge pipe discharge, make new medium get into and continue to carry out the heating up and cooling to jar body and handle, the temperature of the internal hydrolysis reaction environment of control jar, guarantee nitro guanidine can be under constant temperature continuous hydrolysis, through the control valve on control inlet pipe and the water injection pipe, make nitro guanidine can constantly hydrolyze under certain temperature reach the nitro guanidine hydrolysis solution of required concentration, use display controller real-time monitoring to adjust the concentration of hydrolysis solution and the temperature in the jar, thereby reduce continuous hydrolysis kettle internal temperature and hydrolysis solution concentration control degree of difficulty, the error that has reduced the temperature and has reduced the influence of temperature to hydrolysis reaction.

The application provides a continuous hydrolysis kettle for producing nitro guanidine, which comprises a tank body and a tank cover, wherein a water injection pipe and an observation port are arranged at the top of the tank cover, a stirring paddle penetrating through the tank cover is arranged on the tank cover, a cover sealing device is arranged at the contact position of the stirring paddle and the top of the tank cover, a gearbox is fixed above the cover sealing device and connected with an output end of a motor, a circle of sealing gasket is arranged inside the edge of the tank cover, and a plurality of buckles are arranged around the outside of the tank cover;

the tank cover is covered at the top of the tank body, a steam injection pipe, a feed pipe, a gas phase discharge pipe, a condensed water inlet pipe and a display controller are arranged on the side wall of the tank body, an interlayer and a coil pipe are additionally arranged on the side wall of the tank body, the bottom of the tank body is in a conical shape, the discharge pipe is connected, the tank body is arranged on a support frame, and a plurality of support legs are welded at the bottom of the support frame;

the water injection pipe, the steam injection pipe, the feeding pipe, the gas phase discharging pipe, the condensed water feeding pipe and the discharging pipe are all provided with control valves, and each control valve is electrically connected with the display controller.

Further, the motor is specifically a servo motor.

Furthermore, the gearbox adopts a D-shaped gearbox.

Further, a display screen and control buttons are arranged on the display controller.

Further, the display controller is electrically connected with a temperature sensor, a pressure sensor and a solution concentration detector.

Further, the steam injection pipe, the gas phase discharge pipe and the condensed water inlet pipe are communicated with the interlayer and the coil pipe.

According to the technical scheme, the continuous hydrolysis kettle for producing the nitroguanidine comprises a tank body and a tank cover, wherein the tank body plays a role in supporting and fixing, is used for fixedly mounting an interlayer and a coil pipe, and is fixedly connected with a steam injection pipe, a feed pipe, a gas phase discharge pipe and a condensate water inlet pipe on the side wall of the tank body, a favorable reaction environment is created for the nitroguanidine hydrolysis, the tank cover mainly plays a role in sealing, the tank body is sealed, the pressure and the temperature in the tank body can reach the pressure and the temperature required by the nitroguanidine hydrolysis, the position of a stirring paddle is fixed, the stirring paddle can sufficiently stir a nitroguanidine hydrolysis solution, so that the nitroguanidine hydrolysis is more efficient, the top of the tank cover is provided with a water injection pipe and an observation port, the water injection pipe is an injection channel for the nitroguanidine hydrolysis reaction with the nitroguanidine in the tank body, the control valve is arranged on the water injection pipe for controlling the water injection quantity, thereby achieving the purpose of controlling the concentration of the nitroguanidine hydrolysis solution, the observation port can observe and know the reaction condition in the tank in real time, is convenient for controlling the condition in the tank, can timely react and timely process when adverse effects such as machine faults or hydrolysis errors occur, reduces the loss, is provided with the stirring paddle penetrating through the tank cover, plays a stirring role, and is driven by the power output structure to stir the mixture of the nitroguanidine and the water, increases the hydrolysis rate of the mixture, thereby improving the production efficiency, and the contact position of the stirring paddle and the top of the tank cover is provided with the capping device, enhancing the sealing performance of the device, reducing the loss of heat and pressure, ensuring the hydrolysis environment of the nitroguanidine, ensuring the constant hydrolysis of the nitroguanidine under certain conditions, reducing the influence of the temperature and the pressure on the hydrolysis of the nitroguanidine, the gearbox is fixed above the capping device, and is used for carrying out variable speed treatment on power output by the motor, so that the power can meet the stable operation of the stirring paddle, the normal operation of the equipment is ensured, the gearbox is connected to the output end of the motor, the power output structure is used for driving the stirring paddle to carry out stirring treatment on a mixture of the nitroguanidine and water after the treatment of the gearbox, so that the hydrolysis rate of the nitroguanidine is accelerated, the whole nitroguanidine preparation process is promoted, a circle of sealing gasket is arranged inside the edge of the tank cover, the sealing performance of the tank cover is enhanced, the sealing effect of the tank cover is better, a plurality of buckles are arranged on the periphery outside the tank cover, the tank cover and the tank body are tightly combined together, the sealing performance of the equipment is further enhanced, the environment required by the reaction is ensured, and the nitroguanidine is strongly supported for hydrolysis;

the tank cover is covered on the top of the tank body, a steam injection pipe, a feed pipe, a gas phase discharge pipe, a condensed water inlet pipe and a display controller are arranged on the side wall of the tank body, the steam injection pipe is a steam injection channel for injecting proper amount of steam, thereby raising the temperature in the tank, enabling the temperature in the tank to reach the temperature required by the hydrolysis of the nitroguanidine, enabling the nitroguanidine to be constantly hydrolyzed at a constant temperature, the feed pipe is a nitroguanidine injection channel for injecting the nitroguanidine, an interlayer and a coil pipe are additionally arranged on the side wall of the tank body, the circulating storage channel for the medium for raising and lowering the temperature of the tank body is communicated with the steam injection pipe, the condensed water inlet pipe and the gas phase discharge pipe, the injection quantity of the steam and the condensed water is controlled by controlling a control valve on the steam injection pipe and the condensed water inlet pipe, and the redundant cold and heat exchange medium is released by controlling a control valve on the gas phase discharge pipe, the novel cold-heat exchange medium is led into the tank body, the constant temperature of the tank body is ensured, so that continuous hydrolysis of the nitroguanidine can be carried out at constant temperature, the influence of the temperature on continuous hydrolysis of the nitroguanidine is reduced, the bottom of the tank body is in a conical shape, a discharge pipe is connected, the conical tank bottom is favorable for completely discharging products after the nitroguanidine hydrolysis, the residue retention rate in the tank body is reduced, the discharge pipe is a discharge channel after the nitroguanidine hydrolysis, the tank body is supported on a supporting frame, the tank body is supported by the bottom of the supporting frame, a plurality of supporting legs are welded at the bottom of the supporting frame, the whole supporting frame is supported, meanwhile, enough installation space is reserved for the installation of the discharge pipe, the discharge pipe is convenient to install, the conical tank body plays the maximum role, the hydrolyzed nitroguanidine solution can be completely discharged out of the tank body, and the pressure and the temperature loss in the tank body are ensured to be the lowest, providing a strong support for the continuous hydrolysis of nitroguanidine;

the control valves are arranged on the water injection pipe, the steam injection pipe, the feeding pipe, the gas phase discharge pipe, the condensed water inlet pipe and the discharge pipe, each control valve is electrically connected with the display controller, the steam injection pipe, the condensed water inlet pipe and the control valve on the gas phase discharge pipe are controlled to be opened and closed, so that the injection and discharge of steam and condensed water are controlled, the temperature in the control tank body is regulated to be constant, the nitroguanidine can be continuously hydrolyzed at constant temperature, the influence of the temperature on the continuous hydrolysis of the nitroguanidine is reduced, the injection quantity of water and the nitroguanidine required by each nitroguanidine hydrolysis is controlled by controlling the opening and closing of the control valves on the water injection pipe and the feeding pipe, the concentration of the nitroguanidine hydrolysis solution can reach the required concentration of the nitroguanidine hydrolysis solution, the nitroguanidine hydrolysis solution is prevented from leaking before the complete hydrolysis of the nitroguanidine is ensured by controlling the opening and closing of the control valve on the discharge pipe, the nitroguanidine hydrolysis solution after the complete hydrolysis is controlled to be matched with the control valve on the water injection pipe and the feeding pipe, the nitroguanidine can be continuously hydrolyzed at constant temperature, and the constant pressure of the nitroguanidine is ensured.

In summary, the beneficial effects of the present application are as follows:

1. the control button is used for adjusting and controlling the opening and closing of the control valves on the steam injection pipe, the condensed water inlet pipe and the gas phase discharge pipe, so that the injection and discharge of steam and condensed water are controlled, the temperature in the pot is ensured to be constant, continuous hydrolysis of the nitroguanidine can be performed at constant temperature, the influence of the temperature on continuous hydrolysis of the nitroguanidine is reduced, and the control button is used for controlling the opening and closing of the control valves on the water injection pipe, the feed pipe and the discharge pipe, so that the influence of the feed and the discharge on the pressure in the pot is not great, and continuous hydrolysis of the nitroguanidine is ensured under constant pressure.

2. The concentration of the hydrolysis solution, the temperature in the tank and the pressure intensity are monitored and regulated in real time by using the display controller, so that the control difficulty of the temperature in the continuous hydrolysis kettle and the concentration of the hydrolysis solution is reduced, the error existing in the hydrolysis process is reduced, and the influence of the error on the hydrolysis reaction is reduced.

3. The stirring paddles are arranged, and after the nitroguanidine is mixed with water, the hydrolysis rate of the nitroguanidine is increased through the stirring of the stirring paddles, so that the production efficiency is improved.

4. The stirring rake is provided with the capping ware with tank cap top contact position, and tank cap edge inside is provided with round sealed pad, and a plurality of buckles are installed around the tank cap outside, and capping ware and sealed pad can strengthen the sealed effect of tank cap, with the tank cap lid on the jar body, closely combine tank cap and jar body together through the buckle to further strengthen the leakproofness of this equipment, thereby guarantee the required environment of reaction, do powerful support for the continuous hydrolysis of nitroguanidine.

Drawings

For a clearer description of the technical solutions of the present application, the drawings that are necessary for the implementation will be briefly described, it being obvious to a person skilled in the art that other drawings can be obtained from these drawings without inventive effort.

Fig. 1 is a schematic structural diagram of the present application.

Illustration of:

the device comprises a 1-tank body, a 2-tank cover, a 3-water injection pipe, a 4-observation port, a 5-motor, a 6-gearbox, a 7-capping device, an 8-buckle, a 9-sealing gasket, a 10-steam injection pipe, an 11-feeding pipe, a 12-stirring paddle, a 13-gas phase discharge pipe, a 14-interlayer, a 15-condensate water inlet pipe, a 16-discharge pipe, a 17-supporting frame, 18-supporting legs and a 19-display controller.

Detailed Description

In order to better understand the technical solutions in the present application, the following description will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the accompanying drawings.

The technical scheme can be seen as follows:

example 1:

see fig. 1.

A continuous hydrolysis kettle for producing nitro guanidine comprises a tank body 1 and a tank cover 2, wherein the tank body 1 plays a supporting and fixing role, is used for fixedly mounting an interlayer 14 and a coil pipe, and is fixedly connected with a steam injection pipe 10, a feed pipe 11, a gas phase discharge pipe 13 and a condensate water inlet pipe 15 on the side wall of the tank body, a favorable reaction environment is created for nitro guanidine hydrolysis, the tank cover 2 mainly plays a role of sealing, the tank body 1 is sealed, the pressure and the temperature in the tank body 1 can reach the pressure and the temperature required by nitro guanidine hydrolysis, the position of a stirring paddle 12 is fixed, the stirring paddle 12 can fully stir a nitro guanidine hydrolysis solution, so that the hydrolysis of nitro guanidine is more efficient, a water injection pipe 3 and an observation port 4 are arranged at the top of the tank cover 2, the water injection pipe 3 is an injection channel of water for nitro guanidine hydrolysis, the water is injected into the tank body 1 to carry out hydrolysis reaction with nitro guanidine, the water injection pipe 3 is provided with a control valve for controlling the water injection amount so as to achieve the purpose of controlling the concentration of the nitroguanidine hydrolysis solution, the observation port 4 can observe and know the reaction condition in the tank in real time, is convenient to control the condition in the tank, can timely react and timely process and reduce the loss when the adverse effects such as machine faults or hydrolysis errors occur, the tank cover 2 is provided with a stirring paddle 12 penetrating through the tank cover to play a stirring role, the mixture of the nitroguanidine and the water is stirred under the drive of the power output structure, the hydrolysis rate is increased, the production efficiency is improved, the contact position between the stirring paddle 12 and the top of the tank cover 2 is provided with a sealing cover 7, the tightness of the equipment is enhanced, the loss of heat and pressure is reduced, the hydrolysis environment of the nitroguanidine is ensured, the nitroguanidine is constantly hydrolyzed under a certain condition, the influence of temperature and pressure on the hydrolysis of the nitroguanidine is reduced, the gearbox 6 is fixed above the capping device 7, the power output by the motor 5 is subjected to variable speed treatment, so that the power can meet the stable operation of the stirring paddle 7, the normal operation of the equipment is ensured, the gearbox 6 is connected to the output end of the motor 5, the power output structure is used for driving the stirring paddle 7 to stir the mixture of the nitroguanidine and water after the output power is processed by the gearbox 6, the hydrolysis rate of the nitroguanidine is accelerated, the whole nitroguanidine preparation process is promoted, a circle of sealing gasket 9 is arranged inside the edge of the tank cover 2, the sealing performance of the tank cover 2 is enhanced, the sealing effect of the tank cover 2 is better, a plurality of buckles 8 are arranged on the periphery outside the tank cover 2, the tank cover 2 and the tank body 1 are tightly combined together, the sealing performance of the equipment is further enhanced, and the environment required by the reaction is ensured, so that the hydrolysis of the nitroguanidine is strongly supported;

the tank cover 2 is covered on the top of the tank body 1, a steam injection pipe 10, a feed pipe 11, a gas phase discharge pipe 13, a condensate water inlet pipe 15 and a display controller 19 are arranged on the side wall of the tank body 1, the steam injection pipe 10 is an injection channel of steam and is used for injecting proper amount of steam, thereby raising the temperature in the tank, the temperature in the tank reaches the temperature required by the hydrolysis of the nitroguanidine, the nitroguanidine is constantly hydrolyzed at a constant temperature, the feed pipe 11 is an injection channel of the nitroguanidine and is used for injecting the nitroguanidine, an interlayer 14 and a coil pipe are additionally arranged on the side wall of the tank body 1, a circulation storage channel of media for raising and lowering the temperature of the tank body is communicated with the steam injection pipe 10, the condensate water inlet pipe 15 and the gas phase discharge pipe 13, the injection quantity of the steam and the condensate water is controlled by controlling a control valve on the gas phase discharge pipe 13, releasing redundant cold-heat exchange medium, allowing new cold-heat exchange medium to enter, ensuring constant temperature in the tank body 1, so that continuous hydrolysis of nitroguanidine can be carried out at constant temperature, thereby reducing the influence of temperature on continuous hydrolysis of nitroguanidine, the bottom of the tank body 1 is in a conical shape, and is connected with a discharge pipe 16, the conical tank bottom is beneficial to completely discharging products after nitroguanidine hydrolysis, the residue retention rate in the tank body 1 is reduced, the discharge pipe 16 is a discharge channel after nitroguanidine hydrolysis, the tank body 1 is supported on a support frame 17, the tank body 1 is supported, a plurality of support legs 18 are welded at the bottom of the support frame 17, the whole support frame 17 is supported, meanwhile, enough installation space is reserved for installation of the discharge pipe 16, the conical tank body plays the maximum role, and the hydrolyzed nitroguanidine solution can be completely discharged out of the tank body 1, meanwhile, the pressure and temperature loss in the tank body is ensured to be the lowest, and a powerful support is provided for continuous hydrolysis of the nitroguanidine;

the water injection pipe 3, the steam injection pipe 10, the feeding pipe 11, the gas phase discharging pipe 13, the condensed water inlet pipe 15 and the discharging pipe 16 are all provided with control valves, each control valve is electrically connected with the display controller 19, the steam injection pipe 10, the condensed water inlet pipe 15 and the gas phase discharging pipe 13 are controlled to be opened and closed by controlling the control valves on the steam injection pipe 10, the condensed water inlet pipe 15 and the gas phase discharging pipe 13, so that the injection and the discharge of steam and condensed water are controlled, the temperature in the control tank 1 is regulated to be constant, the nitroguanidine can be continuously hydrolyzed at constant temperature, the influence of the temperature on the continuous hydrolysis of the nitroguanidine is reduced, the injection quantity of water and the nitroguanidine required by each nitroguanidine hydrolysis is controlled by controlling the opening and closing of the control valves on the water injection pipe 3 and the feeding pipe 11, the concentration of the nitroguanidine hydrolysis solution can reach the required concentration of the nitroguanidine hydrolysis solution, the nitroguanidine hydrolysis phenomenon can not occur before the complete hydrolysis is guaranteed by controlling the opening and the discharge of the nitroguanidine hydrolysis solution after the complete hydrolysis, the nitroguanidine hydrolysis solution is controlled to be discharged, the nitroguanidine hydrolysis is controlled, and the constant temperature and the continuous hydrolysis pressure of the nitroguanidine can not be influenced by the constant pressure of the continuous hydrolysis tank.

As a preferred embodiment, the motor 5 is particularly a servo motor, realizes closed-loop control of position, speed and moment, overcomes the problem of step motor out-of-step, has strong overload resistance, can bear load three times of rated torque, accords with the characteristics of instantaneous load fluctuation, quick start requirement and the like of a stirring paddle of the continuous nitroguanidine hydrolysis kettle, and ensures the normal operation of the equipment.

In the preferred embodiment, the gearbox 6 is a D-type gearbox, the high torque resistance of the gearbox is utilized, the output torque of the gearbox is improved by adopting a mode of improving the reduction ratio, the requirement on input torque is reduced, the power of the motor 5 is reduced, and the energy-saving purpose is achieved.

As the preferred embodiment, be provided with display screen and control button on the display controller 19, can observe temperature, pressure and nitroguanidine hydrolysis solution's in the jar concentration through the display screen real-time, make things convenient for the temperature in the timely adjustment jar of people and control water and nitroguanidine's injection amount, prepare the nitroguanidine hydrolysis solution of required concentration, be provided with control button, the switching of every control valve is controlled through control button, and is simple and convenient, still efficient.

As the preferred embodiment, the display controller 19 is electrically connected with a temperature sensor, a pressure sensor and a solution concentration detector, and is arranged in the tank body 1, and is used for detecting and sensing in real time through the temperature sensor, the pressure sensor and the solution concentration detector, transmitting the sensing to a display screen of the display controller 19, facilitating people to respond timely, and adjusting the temperature, the pressure and the solution concentration in the tank body 1 by controlling the opening and closing of a control valve through a control button, so that the continuous hydrolysis of the nitroguanidine and the production of the nitroguanidine hydrolysis solution with the required concentration are supported forcefully.

As a preferred embodiment, the steam injection pipe 10, the gas phase discharge pipe 13 and the condensate water inlet pipe 15 are communicated with the interlayer 14 and the coiled pipe, so that the temperature in the tank is conveniently controlled by steam and condensate water, the nitroguanidine can be continuously hydrolyzed at a constant temperature, and the influence of the temperature on the continuous hydrolysis of the nitroguanidine is reduced.

Other embodiments of the present application will be apparent to those skilled in the art from consideration of the specification and practice of the application disclosed herein. This application is intended to cover any variations, uses, or adaptations of the application following, in general, the principles of the application and including such departures from the present disclosure as come within known or customary practice within the art to which the application pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope of the application being indicated by the following claims.

It is to be understood that the present application is not limited to the precise arrangements and instrumentalities shown in the drawings, which have been described above, and that various modifications and changes may be effected without departing from the scope thereof. The above-described embodiments of the present application are not intended to limit the scope of the present application.

Claims

1. The utility model provides a be used for continuous hydrolysis kettle of nitro guanidine production, its characterized in that includes, jar body (1) and cover (2), cover (2) top is provided with water injection pipe (3) and viewing aperture (4), install one stirring rake (12) that runs through cover (2) on cover (2), stirring rake (12) with cover (2) top contact position is provided with closing cap ware (7), closing cap ware (7) top is fixed with gearbox (6), gearbox (6) select for use "D type" gear box, gearbox (6) are connected at motor (5) output, motor (5) are specifically servo motor, cover (2) edge inside is provided with round sealing pad (9), a plurality of buckle (8) are installed all around to cover (2) outside.

The novel solar energy water heater is characterized in that the tank cover (2) is covered at the top of the tank body (1), a steam injection pipe (10), a feed pipe (11), a gas phase discharge pipe (13), a condensed water inlet pipe (15) and a display controller (19) are arranged on the side wall of the tank body (1), a display screen and a control button are arranged on the display controller (19), the display controller (19) is electrically connected with a temperature sensor, a pressure sensor and a solution concentration detector, an interlayer (14) and a coil pipe are additionally arranged on the side wall of the tank body (1), the steam injection pipe (10), the gas phase discharge pipe (13) and the condensed water inlet pipe (15) are communicated with the interlayer (14) and the coil pipe, and a discharge pipe (16) is connected, the tank body (1) is arranged on a support frame (17), and a plurality of support legs (18) are welded at the bottom of the support frame (17).

The water injection pipe (3), the steam injection pipe (10), the feeding pipe (11), the gas phase discharging pipe (13), the condensed water inlet pipe (15) and the discharging pipe (16) are respectively provided with a control valve, and each control valve is electrically connected with the display controller (19).

2. The continuous hydrolysis tank for the production of nitro guanidine according to claim 1, characterized in that the bottom of the tank (1) is arranged in a "conical" shape.