HRP20120691A2 - Marine flue gases purifier with sox removing and dry separation of solid particles - Google Patents

Abstract

The technical problem that must be solved by the present invention is to find a solution for desulphurization and removal of soot from combustion gases in marine applications for environmental protection as well as to save energy and increase ship safety, and avoid the risk of fire in engine exhaust boilers. This problem is solved by a marine exhaust gas purification device consisting of a fan-separator (1) with an axial-radial type rotor equipped with axial blades (1.7) curved into radial part (1.8) for centrifugal ejection of solid particles through the free cross section ( 1.12) which have a bent end so that part of the solid particles from the centrifugal separator part (1.8) does not escape into the pressure centrifugal blades (1.6) and the centrifugal part for expelling the received exhaust gases containing separate soot through the free cross section (1.12). is connected to a fan-separator containing wet filters (5) with nozzles (6) for spraying seawater, a heat exchanger (2) which is connected between the fan-separator and a desulphurisation device for heat exchange between partially purified exhaust gases from the fan - separators and purified exhaust gases from the desulphurisation plant.

Description

The field to which the invention relates

The invention relates to ecology, that is, the purification of exhaust gases from harmful substances created by the combustion of fossil fuels in marine engines and boilers.

Technical problem

Combustion of fossil fuels containing sulfur produces sulfur oxides (SOX) and solid particles in the form of soot, ash and unburned hydrocarbons. All these combustion products are harmful to the environment. The IMO organization (International Maritime Organization) has begun to introduce restrictions on the use of heavy fuel (fuel oil) with a high sulfur content in ports and some protected zones, which will be significantly expanded in 2015, while by 2020 all the world's must. Ships have the option of using sulfur-free fuel (euro diesel), or heavy cheap fuel with a high sulfur content, but with a built-in device for desulfurization and filtering of solid particles.

State of the art

There are several manufacturers of marine SOX scrubbers such as Wartsila, Aalborg - Alfalaval, Hamworthy, which have started production. The principle of operation is similar for all of them, and it consists in the fact that exhaust gases from engines or boilers are mixed with water in channels or nozzles for cooling, fed to the bottom of the desulphurization device and led vertically upwards (to the wet filter), where the wet soot is now heavier falls to the bottom of the device. Sooty water is cleaned of soot in separators, which is then stored in tanks. After passing through wet filters, where sulfur oxides chemically bond with water and form sulfuric acid, its neutralization is done by dosing sodium lye (NaOH).

A steam heater is installed at the end of the device, which heats the now cooled exhaust gases to a certain temperature, in order to avoid the formation of a white cloud of condensate at the exit of the ship's chimney. This represents a large expenditure of energy.

Presentation of the essence of the invention

The goal of the invention is to find a new solution for exhaust gas desulphurization for the purpose of saving energy and increasing the safety of the ship, avoiding the risk of fire outbreaks in engine exhaust gas boilers.

The exhaust gases are cleaned of soot and other solid particles in a specially designed fan-separator and lead to the upper part of the desulphurization device, where the gas-gas cross heat exchanger is located, i.e. the hot exhaust gases entering the device are cooled, and at the same time heated cooled gases at the exit from the device. With this design of the heat exchanger, the device cools itself, that is, it heats itself with energy that is thrown into the environment by other systems. When the device is used to desulphurize the exhaust gases of a marine engine, and behind which, as a rule, an exhaust gas boiler 12 is always installed, which serves for energy utilization, the fan - separator, as an integral part of the purifier, is installed before the exhaust gas boiler 12 (shown in Figure 2). With this solution, the exhaust gas boiler is protected from the formation of soot deposits, and the risk of fire in the exhaust gas boiler is avoided, which increases the safety of the ship and the efficiency of the exhaust gas boiler itself, since there is no drop in capacity due to contamination.

A short list of drawings

Figure 1: Section of the device

Figure 2: Position of the fan - separator in relation to the engine and the exhaust gas boiler

Figure 3: Longitudinal section of fan - separator

Figure 3a: Cross section (A-A) of fan - separator

Figure 4: Construction of the heat exchanger on top of the desulfurization device

Figure 5: Construction of wet filters

A detailed description of at least one way of realizing the invention

The exhaust gases are cleaned of soot using the fan - separator 1, which is introduced through the pipe 10 from the separator channel into the bag filter 11 and collected in the container. In this case, we have dry separation of soot and other solid particles, unlike other existing devices that have wet separation. The cleaned gases enter the heat exchanger 2, the construction of which can be seen in Figure 4, which is located on top of the desulphurization device, and which is composed of a large number of rectangular tubes that are polished on both the inside and the outside, in order to increase the heating surface.

The hot gases enter the inner channels of the rectangular tube, and are cooled by the gases previously cooled in the desulphurization device itself, which pass through the outer channels of the rectangular tube. As you can see, it is a cross heat exchanger. The cooled gases enter the channel 3, in which the temperature of the gases is further lowered with the help of sea water, which is supplied through the nozzles 4, which are installed in a counter current. At the same time, the desulphurization process begins in the channel, that is, the chemical bonding of sulfur oxides with seawater, and the formation of sulfuric acid. Sulfuric acid is simultaneously neutralized due to the alkaline nature of seawater. From channel 3, the now completely cooled exhaust gases enter the lower part of the purifier and pass upwards through the first wet filter 5, a structure visible in Figure 5, being sprayed with sea spray from nozzles 6. In the first stage, the bulk of desulfurization takes place. In the second wet filter 5, construction visible in Figure 5, additional desulphurization takes place to a very high percentage. Wet filters 5 are composed of a very large number of polypropylene plates that have a large number of shoots on them, in order to achieve a large exchange surface. After passing through the second stage, the exhaust gases pass through the cross exchanger, which was described at the beginning, and the construction is visible in Figure 4, where they are heated and pass through the ship's chimney into the atmosphere. The dispersed sea is collected at the bottom of the purifier, and it is thrown out of the ship through pipe 8. The sea that is ejected from the ship is clear, because the soot was separated in the fan - separator, and contains only sulfates as products of neutralization of sulfuric acid. Sulfates, i.e. gypsum, are allowed to be released into the sea because they are completely harmless. Connection 9 serves for, if necessary, complete emptying of the purifier.

Fan - separator 1, as one of the most important parts of the purifier, is assembled as follows:

The rotor is cantilever-suspended on the electric motor using hub 1.1. The base plate 1.2 is attached to the hub with screws, to which the pipe 1.3 is welded, which serves as a support for the vanes 1.6, 1.7 and 1.8. Between the base plate 1.2 and the tube 1.3, a cone-shaped tube 1.4 is welded with a radius in order to minimize flow resistance. The rotor is axial-radial type. At the entrance to the rotor, axial blades 1.7 are placed, which are welded to radial blades 1.8, which in this case are separator blades. The number of blades 1.7 and 1.8 is chosen so that the blades capture soot from the exhaust gases before the exhaust gases leave the separator section. Separator blades 1.8 are bent at their end to catch soot and centrifugally eject it through channel 1.12. From the section A - A in Figure 3, it can be seen that a partition 1.10 and a partition 1.11 are welded between the separator blades 1.8 in order to reduce the free section 1.12 through which a small amount of exhaust gases mixed with separated soot flows.

Method of application of the invention

In this way, the invention enables a new exhaust gas desulfurization technology that simplifies the system and makes it competitive.

List of used call signs

1 Fan - separator

1.1 Rotor hub

1.2 Rotor base plate

1.3 Blade holder

1.4 Conical rotor sheet

1.5 Conical rotor inlet

1.6 Main centrifugal blades

1.7 Axial vanes

1.8 Separator vanes

1.9 Lateral conical covers of separator blades

1.10 Partition sheets of separator blades

1.11 Partition sheets of separator blades

1.12 Free cross-section for the outflow of exhaust gas mixed with separated soot

2 A simplified heat exchanger, Figure 4

3 Connecting channel of the upper and lower parts of the purifier

4 Nozzles in the channel

5 Polypropylene needle plates of wet filters, picture 5

6 Wet filter nozzles

7 Gas outlet from the purifier

8 The outlet pipe of the sea

9 Exhaust - drainage hole

10 Output of separated carbon black

11 Bag filter

12 Engine exhaust gas boiler

Claims (10)

1. On-board SOX flue gas purifier with dry separation of solid particles characterized by: - Fan - separator (1) for receiving exhaust gases from engines or boilers, with an axial-radial type rotor equipped with axial blades (1.7) curved in the radial part (1.8) for centrifugal ejection of separated soot through the free section (1.12), which have a bent end so that part of the solid particles from the centrifugal separator part (1.8) does not escape into the pressure centrifugal blades (1.6) - a desulfurization device that has an inlet connected to the fan outlet - a separator for desulfurization of partially purified exhaust gases, a desulfurization device that contains wet filters (5) with nozzles (6) that cover the exhaust gases with seawater, and an outlet for the transfer of purified flue gases, - a heat exchanger (2) which is connected between the outlet of the fan-separator (1) and the outlet of the desulphurization device for the purpose of exchanging heat between partially purified and purified exhaust gases, with the fact that the partially purified exhaust gases are cooled before entering the wet filters (5 ) and the purified exhaust gases are heated after leaving the desulphurization device. 2. Ship's SOX flue gas purifier with dry separation of solid particles according to claim 1, characterized in that the exchanger (2) is composed of rectangular tubes, polished on the outside and inside. 3. Marine SOX flue gas scrubber with dry separation of solid particles according to requirements 1 or 2, characterized by the fact that the exchanger is placed on top of the desulphurization device. 4. Shipboard SOX flue gas purifier with dry separation of solid particles according to any of the previous requirements, characterized in that the desulphurization device is connected to the heat exchanger (2) through a channel (3) in which nozzles (4) are installed for wetting with sea water. 5. Ship's SOX flue gas purifier with dry separation of solid particles according to any of the previous requirements, characterized in that the wet filters (5) are made of polypropylene plates that have a large number of needles on one side. 6. Marine SOX flue gas purifier with dry separation of solid particles according to any of the previous requirements, characterized in that the fan-separator (1) has laterally connected partition sheets (1.9, 1.10, 1.11) that close the separator blades (1.8). 7. Marine SOX flue gas purifier with dry separation of solid particles according to any of the previous requirements, indicated by the fact that the rotor has a built-in conical cap (1.5). 8. Marine SOX flue gas scrubber with dry separation of solid particles according to any of the previous requirements, characterized in that the rotor has radius-shaped conical tubes (1.4) to which the main centrifugal blades (1.6) are welded. 9. Marine SOX flue gas purifier with dry separation of solid particles according to any of the previous requirements, characterized in that the bag filter for soot (11) is connected to the channel (1.12) of the fan - separator (1). 10. Marine SOX flue gas scrubber with dry separation of solid particles according to any of the preceding claims, characterized in that the electric motor is connected to the rotor.