CN204953165U - Two venturi ceramic nozzle device again - Google Patents

Abstract

A double-venturi ceramic nozzle device is composed of: the first Venturi structure contraction section, the first Venturi structure throat, the first Venturi structure diffusion section, the critical flow velocity nozzle orifice, the orifice throat, the second Two Venturi structure diffusion sections, corundum ceramics, and stainless steel sleeves, the nozzle inlet of the critical flow rate is provided with the first Venturi structure contraction section, the middle of the nozzle is provided with the first Venturi structure throat, and the nozzle mouth is provided with the first Venturi structure diffusion section , the critical flow velocity nozzle orifice plate is set inside the nozzle mouth, and the second Venturi structure diffusion section is set outside the orifice plate; a hole is reserved in the middle of the critical flow velocity nozzle orifice plate, and a stainless steel sleeve is set in the hole. The hole is reserved, and the throat of the orifice plate is set in the hole; the double Venturi structure slows down the direct erosion of the nozzle and the throat diameter; the use of corundum ceramics improves the wear resistance of the critical flow rate nozzle by at least twice, ensuring the critical flow rate of the nozzle. service life.

Description

A double-venturi ceramic nozzle device

technical field

The utility model relates to a critical velocity nozzle for regenerated flue gas, in particular to a double-venturi ceramic nozzle device.

Background technique

At present, the critical flow rate nozzle is the key component of the catalytic cracking unit to control the pressure balance of the tertiary cyclone separator and the quantitative flow of flue gas into the smoke machine. Its working temperature can reach 700°C, the flue gas flow rate can reach 200m/s, and it is eroded by the air flow containing a small amount of catalyst particles. The quality of its working conditions directly affects the efficiency of catalyst recovery by the three-stage cyclone separator, the power generation capacity of the smoke machine, and the stable operation of the smoke machine; in the 1990s, the cobalt-based alloy Venturi structure critical velocity nozzle was adopted, which became the main application of critical velocity nozzles in my country form. After 2000, my country's catalytic cracking unit increased the operating cycle to three years, because the most serious wear of the catalytic cracking unit is the wear of the orifice body and nozzle throat outlet by the vortex formed by the catalyst and gas; the critical flow rate of the orifice structure Nozzles have become the mainstream again. In recent years, the operating cycle of some catalytic cracking units has reached more than four years, but the wear resistance of critical flow rate nozzles is poor and cannot meet the three-year service cycle. New growth requirements are put forward for the life cycle of critical flow rate nozzles; in view of the above reasons, The wear resistance of the critical velocity nozzle of the existing catalytic cracking unit in our country is poor, and the service life of the nozzle is less than three years. Now a ceramic nozzle device with double Venturi has been invented.

Utility model content

The purpose of this utility model is to overcome that the current catalytic cracking unit in our country improves the operation period to four years or more, and the orifice structure critical flow velocity nozzle cannot meet the service period of four years or more. Through reasonable design, it provides A ceramic nozzle device with double Venturi and double Venturi structure. The first structure increases the pressure drop of the nozzle with a certain critical flow velocity before the orifice plate, slowing down the impact of flue gas and catalyst on the orifice body of the critical flow velocity nozzle and the throat diameter of the orifice plate. The second structure interferes with the vortex flow of flue gas and catalyst at the outlet, and slows down the wear of the orifice plate body and the orifice throat diameter outlet.

In order to achieve the above object, the utility model adopts the following technical scheme: a double-venturi ceramic nozzle device is composed of: the first Venturi structure shrinkage section, the first Venturi structure throat, and the first Venturi structure diffusion section , critical flow rate nozzle orifice, orifice throat, second Venturi structure diffusion section, corundum ceramics, stainless steel sleeve, the critical flow rate nozzle inlet is provided with the first Venturi structure contraction section, and the middle of the nozzle is provided with the first Venturi structure throat The first Venturi structure diffusion section is set at the nozzle mouth, the critical velocity nozzle orifice plate is set inside the nozzle mouth, and the second Venturi structure diffusion section is set outside the critical velocity nozzle orifice plate; the hole is reserved in the middle of the critical velocity nozzle orifice plate, A stainless steel sleeve is arranged in the hole, a corundum ceramic is arranged in the stainless steel sleeve, a hole is reserved in the middle of the corundum ceramic, and an orifice throat is arranged in the hole.

The beneficial effects of the utility model are: adopting the Venturi double structure, slowing down the direct erosion of the flue gas and the catalyst on the orifice plate body and the throat diameter of the nozzle; corundum is a material whose hardness is second only to diamond in nature, and its wear resistance is much higher than that of stainless steel , higher than the surfacing alloy, using corundum ceramics, improving the wear resistance of the critical flow rate nozzle at least twice, ensuring the service life of the critical flow rate nozzle.

The flue gas of the utility model enters the inlet of the critical velocity nozzle, which is the inlet end of the first Venturi structure contraction section. The flue gas decelerates continuously through the contraction section, and reaches the throat of the Venturi structure and decelerates to the maximum value. The pressure drop of the critical velocity nozzle is now Throat pressure drop of the first Venturi structure plus orifice throat pressure drop: The pressure drop of the critical velocity nozzle of the current orifice structure is equal to the orifice throat pressure drop.

The orifice throat and the diffusion section of the second Venturi structure form the second Venturi structure.

The connection between the corundum ceramic and the orifice plate is through a stainless steel sleeve, the stainless steel sleeve and the corundum ceramic are mechanically connected, and the stainless steel sleeve and the orifice plate are welded.

Description of drawings

Below in conjunction with accompanying drawing, the utility model is further described:

Figure 1 is a schematic diagram of the assembly structure;

Fig. 2 is a schematic diagram of a cross-sectional structure of a nozzle orifice;

In Figure 1.2: the first Venturi structure contraction section 1, the first Venturi structure throat 2, the first Venturi structure diffusion section 3, the critical velocity nozzle orifice 4, the orifice throat 5, and the second Venturi structure diffusion Section 6, corundum ceramics 7, stainless steel cover 8.

detailed description

Below in conjunction with accompanying drawing and specific embodiment the utility model is described in further detail:

The inlet of the critical flow rate nozzle is provided with the first Venturi structure contraction section 1, the middle part of the nozzle is provided with the first Venturi structure throat 2, the nozzle mouth is provided with the first Venturi structure diffusion section 3, and the critical flow rate nozzle orifice is provided inside the nozzle mouth 4. The second Venturi structure diffusion section 6 is set on the outer side of the nozzle orifice plate 4 of the critical flow rate; a hole is reserved in the middle of the critical flow rate nozzle orifice plate 4, and a stainless steel sleeve 8 is set in the hole, and a corundum ceramic 7 and a corundum ceramic 7 are set in the stainless steel sleeve 8 A hole is reserved in the middle, and an orifice throat 5 is arranged in the hole.

Claims (2)

1. A ceramic nozzle device with double Venturi structure is composed of: the first Venturi structure contraction section (1), the first Venturi structure throat (2), the first Venturi structure diffusion section (3), critical Flow rate nozzle orifice plate (4), orifice plate throat (5), second Venturi structure diffusion section (6), corundum ceramics (7), stainless steel sleeve (8), is characterized in that: the critical flow rate nozzle inlet is set The first Venturi structure shrinkage section (1), the first Venturi structure throat (2) is set in the middle of the nozzle, the first Venturi structure diffusion section (3) is set at the nozzle mouth, and the critical velocity nozzle orifice plate is set inside the nozzle mouth (4), the critical velocity nozzle orifice plate (4) is provided with a second Venturi structure diffusion section (6). 2. according to the ceramic nozzle device of a kind of double Venturi described in claim 1, it is characterized in that: critical velocity nozzle orifice plate (4) middle part reserves hole, and stainless steel sleeve (8) is set in the hole, stainless steel sleeve ( 8) is provided with a corundum ceramic (7), a hole is reserved in the middle of the corundum ceramic (7), and an orifice throat (5) is provided in the hole.