SYSTEM FOR FILTERING RESIDUAL CONTAMINANT PARTICLES FOR SMOKES AND GAS THROUGH ATOMIZED ULTRAFREEZING

Abstract: The invention discloses a filter (1) having an inlet mouth (4), through which a contaminated fluid (gas or smokes) can pass to the inside of the filter, at an appropriate temperature, and mixes there with fine water drops and then with liquid nitrogen flowing through showers (9, 10), all of which forming a hail-like mass which precipitates to a decanter (14) whre the separation of solidified contaminant particles will take place, said particles coming out to the outside through a discharge valve (15) while clean air will be expelled to the atmosphere through a chimmney (17). It is provided, as a second option, to incorporate a coil as a substituion to liquid nitrogen showers mentioned hereabove. Finally, it is to be noted that it is possible to avoid said water drops, depending on the type of contaminated fluid.

Description: The present invention refers to a system for filtering residual contaminant particles for smoke and gas through atomized ultrafreezing, which proves to be a very efficient and low cost system in comparison with other conventional ones that carry out the same function. It advantageously avoids contaminant particles and gas from coming out to the outside, without thus producing "acid rain", which seriously harms plants. On the other hand, this system of the invention allows some elements of the residual product to be recovered. Presently, different systems to purify gas and smoke consisting of water baths or baths of other liquids that act as a filter for the products to be purified are known. The efficiency of said systems is not as good as would be expected, whereas the cost of the assembly and installation thereof is very high. Besides, the purification is not totally correct, which implies that some contaminant elements come out to the outside after purification. WO-A-92/08937 discloses an apparatus according to the preambles of claims 1 and 2 of this patent. To overcome the above mentioned problems, the invention proposes a system for filtering residual contaminant particles for smoke and gas through atomized ultrafreezing, mainly preventing the contaminant elements that cause the so-called "acid rain" from being expelled to the atmosphere. Another important feature is that the cost of assembly and installation of the unit is relatively inexpensive. In short, it is a very efficient system. The smoke to be purified passes first of all through a top inlet mouth and then continues until it reaches a Venturi-type valve, that regulates the speed of the smoke or gas, that then passes through a group of sprayed or atomized water injectors, then forming a fine rain, which is then ultrafreezed by the action of two liquid nitrogen showers, which will cause an advantageous solidification of the fine rain into a hail-like mass, which then precipitates to a bottom decanter. The decanter includes two separators, one which retains the precipitated hail that later comes out through a discharge valve and a second slower separator inserted before the outlet mouth or chimney, through which the totally purified air is expelled to the atmosphere. On the other hand, for the purpose of reducing the liquid nitrogen consumption and as a second embodiment, replacement of the showers of this gas by a coil protected by a suitable insulating material is provided for, at the same time that it will be placed outside over the decantation duct, said coil occupying part of the bottom decanter. Depending on the temperature of the fluid (smoke or gas) to be purified, inclusion of a heat exchanger when it is necessary to reduce the temperature of the fluid or a condenser when it is necessary to increase said temperature, in the inlet mouth has been provided for. This particular fact is important, since in order to attain total efficiency of the system, it is necessary for the fluid to be at the most suitable temperature upon entering the system. Depending on the type of fluid to be purified, there is the possibility of using or not using atomized water injectors. Hereinafter to provide a better understanding of this specification and forming an integral part of the same, a series of figures wherein the object of the invention has been represented in an illustrative and non-restrictive manner is attached hereto. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic view of the entire system for filtering residual contaminant particles for smoke and gas through atomized ultrafreezing, object of the invention. Among other elements, it includes some liquid nitrogen showers to solidify the contaminant products. Figure 2 is a view similar to the previous one, wherein the liquid nitrogen showers have been replaced by an outside coil through which said liquid nitrogen flows in order to condense or freeze the contaminant products. DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the numbering used in figure 1, the system for filtering residual contaminant particles for smoke and gas through atomized ultrafreezing is defined by a filter supported by a housing (1) whose entire surface is provided with an insulating material (2), at the same time that it rests on some legs (3). In principle, the filter has a top inlet mouth (4) through which the contaminant fluid which is to be completely purified passes, such as smoke or gas, which then reach a Venturi-type valve, provided with a regulator (6) to vary the speed of the contaminant fluid. The incorporation of a fluid temperature regulator (7), such as a heat exchanger to reduce the temperature or a condenser to prevent liquation, in the inlet mouth (4) has been provided for. This regulator element (7) is important, since the same keeps the temperature of the contaminant fluid at the suitable degrees when it passes through the inlet mouth (4), thus achieving in subsequent stages of the process, a correct and efficient purification. Continuing the process and the flow of fluid, the latter will pass from the Venturi valve (5) propelled by the valve to a group of atomized or sprayed water injectors (8), thus forming a fine rain, which will then solidify, in the form of hail, by the action of two liquid nitrogen showers (9) and (10), said hail then precipitating to a bottom decanter (11). The water that feeds the injectors (8) comes from an outside duct (12). The nitrogen that feeds the two showers (9) and (10) also comes from another outside duct (13). Hence, the decanter (11) incorporates a first separator (14) that retains the precipitated hail that later comes out through a discharge valve (15), and a slower second separator (16), which is inserted outside before the outlet mouth (17) or chimney, through which the totally purified fluid is expelled to the atmosphere. On the other hand, cleaning by ultrasound takes place in the decanter (11) which permits the contaminant elements to be separated from the hail-like mass, in such a way that these contaminant elements will come out solidified through the discharge valve (15), at the same time that the same, in some cases, include residue capable of being recycled. The separator (16) that is close to the outlet mouth (17) can also be called a drop separator, since the hail that has been previously collected by the first separator (14) practically does not reach the same. In figure 2, the liquid nitrogen showers (9) and (10) have been advantageously replaced by the outside coil (18) thereof coupled around the down pipe (19) where said showers (9) and (10) were located, this coil occupying part of the bottom decanter (11). The outside coil (18) through which the liquid nitrogen will flow closed-circuit, is covered by a suitable insulating material (20), at the same time that it has an inlet duct (21) and another outlet duct (22). With this arrangement, cooling is caused by said outside coil (18) over the down pipe (19) and part of the bottom decanter (11). Depending on the cooling efficiency, the contaminated fluid can be condensed or frozen, as is done with the atomized nitrogen when it flows through the showers (9) and (10). The consumption of liquid nitrogen is reduced considerably upon using the outside coil (18), at the same time that the liquid nitrogen will not mix with the contaminated fluid as in the case of the nitrogen showers (9) and (10); therefore, subsequent separation thereof will not be necessary.

Claims: An apparatus for filtering residual contaminant particles for smoke and gas through atomized ultrafreezing by liquid nitrogen, comprising an inlet mouth (4) leading to a down pipe (19) with liquid nitrogen means, said down pipe entering and forming part of a housing (1) inside of which a filter is housed, part of the said filter consisting of a decanter (11), the decanter comprising two separators (14,16), one (14) of said separators being located close to a discharge valve (15) in the lower part of the housing (1), the other separator (16) being located close to the outlet mouth (17), and an outlet mouth (17) or chimney extending from the housing (1), characterized in that it also comprises a contaminant fluid temperature regulating element (7) in the inlet mouth (4), a Venturi-type valve (5) provided with a fluid speed regulator (6), said Venturi-type valve (5) being located between the inlet mouth (4) and the down pipe (19), atomized water injectors (8) located directly after the Venturi-type valve (5), and an ultrasound cleaning device for effecting ultrasound cleaning inside decanter (11) in order to separate the contaminant particles from the hail, whereby the liquid nitrogen means comprises liquid nitrogen showers (9,10) located directly after the water injectors, said water injectors (8) are capable of forming a fine rain and the liquid nitrogen showers (9,10) are capable of solidifying the said fine rain in the form of hail, separator (14) is capable of retaining the said hail, and discharge valve (15) is capable of discharging the separated contaminant particles and hail previously retained by separator (14). An apparatus for filtering residual contaminant particles for smoke and gas through atomized ultrafreezing by liquid nitrogen, comprising an inlet mouth (4) leading to a down pipe (19) with liquid nitrogen means, said down pipe entering and forming part of a housing (1) inside of which a filter is housed, part of the said filter consisting of a decanter (11), the decanter comprising two separators (14,16), one (14) of said separators being located close to a discharge valve (15) in the lower part of the housing (1), the other separator (16) being located close to the outlet mouth (17), and an outlet mouth (17) or chimney extending from the housing (1), characterized in that it also comprises a contaminant fluid temperature regulating element (7) in the inlet mouth (4), a Venturi-type valve (5) provided with a fluid speed regulator (6), said Venturi-type valve (5) being located between the inlet mouth (4) and the down pipe (19), and atomized water injectors (8) located directly after the Venturi-type valve (5), and an ultrasound cleaning device for effecting ultrasound cleaning inside decanter (11) in order to separate the contaminant particles from the hail, whereby the liquid nitrogen means comprises an external closed-circuit coil (18) through which the liquid nitrogen flows, said coil being coupled around external portions of the down pipe (19) and part of the decanter (11), said external coil (18) being covered by a suitable insulating material (20), said water injectors (8) are capable of forming a fine rain and the external liquid nitrogen closed-circuit coil (18) is capable of solidifying the said fine rain in the form of hail, separator (14) is capable of retaining the said hail, and discharge valve (15) is capable of discharging the separated contaminant particles and hail previously retained by separator (14).

Inventors: MORO FRANCO EUSEBIO, MORO FRANCO, EUSEBIO
Applicants: MORO FRANCO EUSEBIO, MORO FRANCO, EUSEBIO
Application year: 1995
Main classification: B01D47
IPC codes: B01D49, B01D8, B01D47