A ship open desulfurization system scrubber

Abstract

The application discloses a ship open desulfurization system scrubber, which is provided with two layers, including a scrubber inner layer and a scrubber outer layer, and a slanting array type air inlet is arranged on the upper portion of the outer wall of the scrubber outer layer; waste gas enters the scrubber from the slanting array type air inlet, and is washed for the first time in the scrubber outer layer; then the waste gas enters the scrubber inner layer from the lower portion of the scrubber inner layer, and is washed for the second time in the scrubber inner layer through a gas-liquid separation vortex plate; and the waste liquid after washing is discharged from the scrubber through a liquid vortex channel of the gas-liquid separation vortex plate in a wall-attached vortex state. The slanting array type air inlet arranged on the upper portion of the scrubber can avoid the threat of waste liquid backflow to the safe operation of a diesel engine, and the gas-liquid separation vortex plate is arranged to realize gas-liquid separation and flow through, so that the waste liquid after washing is discharged from the scrubber in a wall-attached vortex state, and the threat of waste liquid backflow to the safe operation of the diesel engine is completely avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of ship diesel engine exhaust gas purification, and particularly relates to a ship open desulfurization system scrubber. BACKGROUND

[0002] With the rapid development of world trade, the amount of goods between countries increases dramatically, and sea transportation undertakes more than 90% of the world's cargo transportation. Diesel engines are widely used as ship propulsion power devices due to their good performance. At present, the ship engine mainly uses low-quality heavy oil as fuel, and the exhaust gas contains a large amount of SO2. The International Maritime Organization (IMO) and the environmental protection department of China have strict emission standards for SO2 emissions of ships. The main measure to meet the relevant emission standards for ship exhaust gas sulfur emissions is to use low-sulfur fuel oil and install a desulfurization tower. Compared with low-sulfur fuel oil, high-sulfur oil has advantages in quality and price, and many studies have shown that for ships in operation and newly built ships, using high-sulfur fuel oil with a desulfurization tower is a more economical way. Many scientific research institutions at home and abroad are committed to the research of ship desulfurization system.

[0003] As an important place for material exchange and reaction in the wet washing process, the wet scrubber has a significant impact on the performance, energy consumption, operation reliability and installation convenience of the wet washing system. The scrubber is generally installed in the chimney above the deck, and there is a high drop from the outlet of the scrubber to the outlet outside the hull. Due to the large flow of the open washing system, the downward "pouring" drainage of the washing liquid is prone to cause poor drainage, thereby causing the washing waste water to backflow, which seriously threatens the normal operation of the diesel engine. The open washing system usually uses seawater as the washing liquid, and compared with the closed system, the open system has limited absorption potential. In order to ensure the desulfurization effect, the spray quantity and the number of spray layers need to be increased, so the height of the open system scrubber is very high, which not only significantly increases the installation difficulty, but also greatly increases the energy consumption of the system. Although many researchers are committed to the research of the open system scrubber, there are still defects in the technology.

[0004] In the patent "A scrubbing tower for exhaust gas desulfurization of a marine diesel engine" with application number 201910025980.3, a Venturi U-shaped tower is used as a washing unit, which will significantly increase the exhaust back pressure of the diesel engine and affect the working performance of the diesel engine. The U-shaped tower occupies a large space, and the use of the upper air inlet method will further increase the exhaust back pressure. The packed tower is not allowed to be dry, so the arrangement of the exhaust gas pipeline will increase the difficulty. The tower body in the present application is not equipped with an overflow pipe, which is easy to cause the formation of a water seal at the exhaust inlet due to the poor flow of the water at the lower part of the tower body, thereby affecting the operation of the system.

[0005] In the patent with application number 201910032733.6, "Marine diesel engine exhaust desulfurization I type desulfurization tower", I type straight tower is used as desulfurization washing tower. In the invention, the water flow at the bottom of the washing tower is prone to cause serious water accumulation at the bottom of the washing tower due to poor water flow, thereby forming backflow. Since the exhaust gas contains PAHs, this type of washing method is prone to cause the PAHs content in the washing liquid to exceed the emission standard limit value of IMO. The exhaust gas temperature is low after I type tower washing, thereby reducing the plume height of the exhaust gas. Therefore, the invention has obvious technical problems. In the patent with application number 201811044107.0, "Ship exhaust gas desulfurization device", a washing tower with a lateral air inlet mode is used as a desulfurization reaction tower. In the invention, a transparent window is opened on the wall of the washing tower, which significantly reduces the strength of the tower body. Since there are many impurities in the washing wastewater, the visibility of the washing liquid is not high, and the transparent window cannot play the role of observing the internal condition of the washing tower. The invention has obvious technical defects.

[0006] In summary, the existing ship desulfurization system washing device has many problems in actual application, and it is necessary to develop a washing device that is reliable in performance, safe, energy-saving and convenient to install. SUMMARY

[0007] The present application provides a ship open desulfurization system washing device, and provides the structure and working principle of the washing device.

[0008] In the present application, the washing device is divided into an inner layer and an outer layer. The diesel engine exhaust gas spirals into the outer layer of the washing device from the oblique array type air inlet at the upper part of the washing device. Under the action of the spray in the outer layer, the exhaust gas spirals downward in the outer layer of the washing device, and the desulfurization process is carried out in the outer layer of the washing device. The exhaust gas washed by the outer layer enters the inner layer below, moves upward in the inner layer of the washing device, and is discharged from the top of the washing device through the gas-liquid separation vortex plate and the washing layer. The washing liquid is discharged in a vortex shape after passing through the gas-liquid separation vortex plate. This discharge mode can significantly improve the problem of washing liquid discharge obstruction, and greatly reduce the threat of washing liquid backflow to the safe operation of the diesel engine.

[0009] The specific working process of the ship open desulfurization system washing device provided by the present application is as follows:

[0010] (1) The ship diesel engine exhaust gas enters the washing device from the oblique array type air inlet at the upper part of the washing device. Under the action of the spray layer above the air inlet, the exhaust gas and the washing liquid move downward, and at the same time, part of the SO2 in the exhaust gas is removed.

[0011] (2) The waste gas enters the inner layer of the scrubber from below after being washed by the outer layer, then moves upward through the gas phase channel of the gas-liquid separation vortex plate, and is sprayed and washed by the spray layer above the gas-liquid separation vortex plate, and then is discharged from the top of the scrubber.

[0012] (3) The spray liquid above the inner layer of the scrubber falls on the liquid phase vortex channel of the gas-liquid separation vortex plate after being washed, and the washing liquid flows downward along the liquid phase vortex channel, and the flow rate gradually increases, then the washing liquid with a larger flow rate spirally flows down from the inner wall of the inner layer of the scrubber, and continuously spirally descends on the discharge channel of the washing liquid, greatly improving the flow smoothness of the discharge.

[0013] Compared with the prior art, the present application has the following advantages:

[0014] (1) In the present application, the waste gas spirally enters the outer layer of the scrubber from the oblique array type gas inlet at the top of the scrubber, which improves the vortex mixing degree of the waste gas and the washing liquid, effectively reduces the height of the scrubber and the washing spray amount, and reduces the energy consumption of the system. Since the waste gas inlet is located at the uppermost part of the scrubber, the present application can reduce the threat of washing liquid backflow to the safe operation of the diesel engine.

[0015] (2) In the present application, the gas-liquid separation vortex plate can realize the simultaneous reverse passing of the waste gas and the washing liquid, and the washing liquid will show a strong vortex downward motion trend under the action of the gas-liquid separation vortex plate. This vortex downward drainage method can greatly improve the flow smoothness of the waste liquid discharged from the scrubber, completely eliminate the threat of washing liquid backflow to the safe operation of the diesel engine, and improve the operation stability of the open desulfurization washing system. BRIEF DESCRIPTION OF DRAWINGS

[0016] Fig. 1 is a schematic diagram of the scrubber of the open desulfurization system of the ship of the present application.

[0017] In Fig. 1, 1 is the outer wall of the outer layer of the scrubber, 2 is the gas-liquid separation vortex plate, 3 is the waste gas inlet, 4 is the waste water outlet, and 5 is the waste gas outlet.

[0018] Fig. 2 is a three-dimensional structure of the outer wall of the outer layer of the scrubber.

[0019] Fig. 3 is the gas-liquid separation vortex plate, in which Fig. 3, 6 is the gas phase channel, and 7 is the liquid phase channel.

[0020] Fig. 4 is a front view of the gas-liquid separation vortex plate, and Fig. 5 is a top view of the gas-liquid separation vortex plate,

[0021] In Fig. 5, 8 is the washing liquid discharge outlet. DETAILED DESCRIPTION

[0022] The exhaust gas of diesel engine enters the scrubber from the oblique arrayed air inlet above the outer layer of the scrubber shown in Fig. 2, and the SO2 removal is carried out under the spraying action of the spraying layer above the oblique arrayed air inlet.

[0023] After the scrubbing action of the outer layer of the scrubber, the exhaust gas enters the inner layer of the scrubber from below the inner layer of the scrubber, then the exhaust gas passes through the gas-liquid separation vortex plate shown as 2 in Fig. 1, and moves upward through the gas phase channel shown as 6 in Fig. 3, and the SO2 removal process is carried out again under the scrubbing action of the upper part of the gas-liquid separation vortex plate.

[0024] The scrubbing liquid of the spraying layer above the gas-liquid separation vortex plate falls onto the liquid phase vortex channel shown as 7 in Fig. 3 after scrubbing the exhaust gas, the scrubbing liquid falling onto the liquid phase vortex channel flows downward with vortex acceleration, and finally passes through the scrubbing liquid discharge shown as 8 in Fig. 5 at high speed in the vortex state, and is discharged to below the scrubber, and flows out of the scrubber in the state of wall-attached vortex, so that the smooth discharge of the scrubbing liquid is realized, and the threat of backflow of the scrubbing liquid to the safe operation of the diesel engine is effectively avoided.

Claims

1. A scrubber for an open FGD system of a marine vessel, characterized in that: The scrubber is provided with two layers, the outer layer is provided with an air inlet on the top, the air inlet is provided with an inclined array type air inlet, a spraying layer is arranged above the air inlet in the outer layer, a gas-liquid separation vortex plate is arranged in the inner layer, a spraying layer is arranged above the gas-liquid separation vortex plate, the gas-liquid separation vortex plate is in an umbrella shape, the gas phase channel and the liquid phase channel are in a spiral shape on the surface of the umbrella shape, the gas phase channel is higher than the umbrella surface, and the liquid phase channel is composed of the wall surface of the gas phase channel, and a washing liquid discharge outlet is arranged at the outlet of the lowermost part of the liquid phase channel of the gas-liquid separation vortex plate.

Images