Installation and operation method of dual control valves in a high pressure fluidized bed system

Abstract

The present invention is directed to a high pressure fluidized bed system using dual control valves, and an inner pressure control method thereof. The high pressure fluidized bed system includes a fluidized bed reactor, a pressure sensor which measures a pressure in the interior of the fluidized bed reactor, a cyclone part which is coupled to the fluidized bed reactor, a first valve allowing controlling of the exhaust gas, and a second valve allowing manually controlling of exhaust gas except for the exhaust gas controlled by the first valve. The first valve is capable of opening and closing automatically, and the second valve is capable of opening and closing manually, and are used in combination in the high pressure fluidized bed, allowing decreasing of the pressure variation within the reactor and improving the operation stability of the reactor.

Claims

1. A high pressure fluidized bed system comprising: a fluidized bed reactor; a pressure sensor which measures a pressure in the interior of the fluidized bed reactor; a cyclone part which is coupled to the fluidized bed reactor, allowing collecting entrained particles and releasing exhaust gas; a first valve which is coupled to the cyclone part and the pressure sensor, allowing controlling the exhaust gas; and a second valve which is coupled to the cyclone part, allowing manually controlling exhaust gas except the exhaust gas controlled by the first valve out of the exhaust gas from which the exhaust gas released from the cyclone part.

2. The high pressure fluidized bed system of claim 1, wherein a permissive flow rate of the second valve is lower than a permissive flow rate of the first valve.

3. The high pressure fluidized bed system of claim 1, wherein the first valve is automatically controlled by a difference between a pressure value measured by the pressure sensor and a set pressure value.

4. The high pressure fluidized bed system of claim 1, wherein the second valve is manually controlled in a state that an opening ratio is not 0.

5. The high pressure fluidized bed system of claim 4, wherein an opening ratio of the second valve is increased and/or decreased in proportion to a velocity in the change of an inner pressure of the fluidized bed reactor.

6. An inner pressure control method of a high pressure fluidized bed system, in the high pressure fluidized bed system according to claim 1, comprising: a first valve setting step for setting up an inner pressure of the fluidized bed reactor as a target value; a gas injecting step for injecting gas into the fluidized bed reactor in a state that the second valve is completely opened; an opening ratio decreasing step for decreasing an opening ratio of the second valve; and a first valve operating step for controlling the first valve to reduce a variation of a pressure of an interior of the fluidized bed reactor.

7. The inner pressure control method of a high pressure fluidized bed system of claim 6, wherein a permissive flow rate of the second valve is lower than a permissive flow rate of the first valve.

8. The inner pressure control method of a high pressure fluidized bed system of claim 6, wherein the first valve is automatically controlled by a difference between a pressure value measured by the pressure sensor and a set pressure value.

9. The inner pressure control method of a high pressure fluidized bed system of claim 6, wherein the second valve is manually control.

10. The inner pressure control method of a high pressure fluidized bed system of claim 6, wherein a velocity in the decrease of an opening ratio of the second valve is controlled in proportion to a velocity in the change of an inner pressure of the fluidized bed.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows a high pressure fluidized bed system according to an exemplary embodiment.

(2) FIG. 2 shows a high pressure fluidized bed system which is equipped with a differential pressure transducer for the test.

(3) FIG. 3 shows a graph for the test using a single pressure control valve according to the related art.

(4) FIG. 4 shows a graph for the test using a dual pressure control valves according to an exemplary embodiment of the present invention.

(5) FIG. 5 shows a high pressure fluidized bed reactor according to the related art.

(6) FIG. 6 shows a fluidization flow regime depending on the gas velocity together with a change in the pressure drop (differential pressure) of a solid bed according thereto.

(7) FIG. 7 shows a high pressure fluidized bed system according to the related art.

DETAILED DESCRIPTION OF THE EMBODIMENTS

(8) The present invention is capable of applied with various modifications and may have diverse embodiments. Thus, particular embodiments will be described accompanying drawing to explain the detailed description of the invention specifically. However, the present invention is not limited to the particular embodiments. It should be understood that the present invention includes all of modifications, equivalents or substitutes which are within the idea and technical scope thereof.

(9) The respective drawings will be described using similar reference symbols for similar elements.

(10) Wording, such as first, second, etc., are used for explaining various elements. However, such elements should be not limited thereto. Such wording is only used for the purpose of distinguishing one element from others.

(11) For example, a first element may be referred to as a second element. Similarly, a second element may be also referred to as a first element. Wording and/or may include any one of a plurality of described items relevant to each other, or any combination thereof.

(12) All terms including technical or scientific terminology used herein has the same meaning as that to be generally understood by a person having ordinary skill in the art to which the present invention pertains, unless otherwise defined.

(13) Terms defined in the generally used dictionary should be understood to have meanings which correspond to contextual meanings of the relevant technology. It should be not interpreted to have an idealistic or excessively formalistic meaning, unless other defined clearly in this application.

(14) A fluidization particle 120 may be provided in the interior of the fluidized bed reactor 100.

(15) A gas supply part 130 may be formed in the lower portion of the fluidized bed reactor 100, allowing supplying gas under the fluidization particle 120.

(16) A discharge part 110 may be formed in a upper portion of the fluidized bed reactor 100, allowing releasing the gas in the interior of the reactor.

(17) The discharge part 110 may be coupled to a cyclone part 300.

(18) The cyclone part 300 may collect and release entrained particles from the fluidized bed reactor 100.

(19) A first valve 410 and a second valve 420 may be coupled to the cyclone part 300.

(20) The first valve 410 may be coupled to the cyclone part 300 and a pressure sensor 200, allowing controlling exhaust gas released from the cyclone part 300.

(21) At this time, the first valve 410 may be automatically controlled by a difference between a pressure value measured by the pressure sensor 200 and a set pressure value.

(22) The second valve 420 may be coupled to the cyclone part 300, allowing manually controlling exhaust gas except the exhaust gas controlled by the first valve 410 out of the exhaust gas from which the exhaust gas released from the cyclone part 300.

(23) At this time, it may be preferable to manually control the second valve 420 in a state that an opening ratio is not 0.

(24) Meanwhile, it may be preferable to increase and/or decrease an opening ratio of the second valve 420 in proportion to a velocity in the change of an inner pressure of the fluidized bed reactor 100.

(25) In other words, the opening ratio of the second valve 420 may be increased when the velocity in the change of the inner pressure of the fluidized bed reactor 100 is rapid, while decreased when the velocity in the change of the inner pressure of the fluidized bed reactor 100 is slow.

(26) The pressure sensor 200 may be equipped to be coupled to the first valve 410 and the fluidized bed reactor 100, allowing measuring a pressure in the interior of the fluidized bed reactor 100.

(27) More particularly, the first valve 410 may be coupled with the pressure sensor 200 which measures an inner pressure of the fluidized bed reactor 100.

(28) The first valve 410 may be an automatic control valve which is automatically opened and closed depending on a difference between an inner pressure (P) of the reactor and a desired set pressure (P.sub.set).

(29) The first valve 410 may be a valve that is capable of opened or closed completely.

(30) Meanwhile, in the case of the second valve 420, a user may control an opening ratio thereof arbitrarily without any sensor such as the pressure sensor 200.

(31) That is, the second valve 420 may be a valve that is capable of operated in a state of having the arbitrarily controlled opening ratio.

(32) The two pressure valves 410 and 420 may be coupled to the side of vent lines formed in a upper portion of the cyclone part 300.

(33) The first valve 410 may automatically control the opening ratio depending on the inner pressure of the fluidized bed reactor 100.

(34) When operating the second valve 420 in a state of not closed completely, that is, the opening ratio is not 0, a portion of the gas injected into the fluidized bed reactor 100 may be discharged through the first valve 410, and the rest thereof may be discharged through the second valve 420.

(35) Accordingly, if the inner pressure of the fluidized bed reactor 100 is increased or decreased, a portion of the gas may be discharged through the second valve 420.

(36) Particularly, in the case that the first valve 410 is closed completely, total gas may be discharged through the second valve 420.

(37) That is, there are the fewer pressure changes in the interior of the reactor as compared with the case that only the first valve 410 is used.

(38) A procedure to adjusting the pressure of the reactor to a desired pressure by increasing the pressure from the atmospheric pressure is as follows.

(39) If setting up a desired pressure (P.sub.set) to the first valve 410 in a state of the atmospheric pressure, since the pressure (P) in the interior of the reactor is lower than the desired pressure (P.sub.set), the first valve 410 may be closed completely.

(40) Hereafter, in a state that the second valve 420 is opened all, that is, the opening ratio is 100%, gas is injected into the fluidized bed system.

(41) On this occasion, since the second valve 420 has been opened completely, the gas may be also discharged through the second valve 420.

(42) At this time, if the opening ratio of the second valve 420 is too high, it may be occurred that the pressure is not increased even though the first valve 410 has been closed.

(43) Therefore, in such case, it may be preferable to decrease the opening ratio of the second valve 420, allowing controlling the pressure by the first valve 410.

(44) At this time, it may be preferable to change the opening ratio of the second valve 420 depending on the velocity in the change of the inner pressure of the reactor.

(45) If the opening ratio of the first valve 410 is changed sharply, it may be preferable to increase the opening ratio of the second valve 420, allowing increasing a flow rate of the gas discharged continuously through the second valve 420.

(46) Meanwhile, if there is too much gas discharged through the second valve 420, it may be occurred that the pressure is not increased even though the first valve 410 has been closed.

(47) In this case, it may be preferable to select, as the second valve 420, a valve which is capable of controlling a low flow rate compared to that the first valve 410.

(48) That is, it may be preferable that the permissive flow rate of the second valve 420 is lower than that of the first valve 410.

(49) Hereinafter, described is a control method of an inner pressure of a high pressure fluidized bed system according to the exemplary embodiment of the present invention.

(50) A fluidization particle 120 may be provided in the interior of the fluidized bed reactor 100.

(51) In the first, an inner pressure of the fluidized bed reactor 100 may be set up as a target value (target pressure value), in a first valve setting step.

(52) In the second, gas may be injected into the fluidized bed reactor 100 in a state that a second valve 420 is completely opened, in a gas injecting step.

(53) In the third, an opening ratio of the second valve may be decreased.

(54) In the fourth, a first valve may be controlled, allowing reducing a variation of the pressure in the interior of the fluidized bed reactor 100, in a first valve operating step.

(55) At this time, it may be preferable that a permissive flow rate of the second valve 420 is lower than that of a first valve 410.

(56) Further, it may be preferable to automatically control the first valve 410 by a difference between a pressure value measured by a pressure sensor 200 and a set pressure value (target pressure value).

(57) Meanwhile, it may be preferable to manually control the second valve 420 and to control a velocity in the decrease of the opening ratio of the second valve 420 in proportion to a velocity in the change of an inner pressure of the fluidized bed 100.

(58) Hereinafter, explained is comparison of a test result cording to an exemplary embodiment of the present invention with a test result according to the related art.

(59) FIG. 2 shows a high pressure fluidized bed system which is equipped with a differential pressure transducer for the test.

(60) A fluidized bed reactor had an inner diameter of 0.052 m and a height of 1.2 m. Nitrogen gas was, as a fluidized gas, injected at a flow rate of 0.014 m/s in a lower portion of the fluidized bed reactor 100.

(61) A fluidization particle 120 used a particle having an average particle size of 101 m, a bulk density of 994 kg/m.sup.3 and a minimum fluidization velocity of 0.0068 m/s, and was charged into a height of 0.6 m inside the fluidized bed reactor 100.

(62) The fluidized bed reactor 100 was equipped with two differential pressure transducers 600, i.e., a first differential pressure transducer 610 and a second differential pressure transducer 620, respectively.

(63) One of such differential pressure transducers, the first differential pressure transducer 610 was coupled to pressure taps installed at each height of 0.09 m and 0.99 m respectively from the bottom of a fluidized bed, allowing measuring a differential pressure.

(64) The other one, the second differential pressure transducer 620 was coupled to pressure taps installed at each height of 0.09 m and 0.39 m respectively from the bottom of the fluidized bed, allowing measuring a differential pressure.

(65) The differential pressures measured at the respective positions represent values in proportion to the height of a solid bed present in the interior of a fluidized bed at the each position.

(66) A pressure in the interior of the fluidized bed was measured by a pressure transducer (hereinafter, referred to as PT) 500.

(67) The test was performed at room temperature. The pressure in the interior of the fluidized reactor 100 was measured by the PT and the pressure drop in the interior of the fluidized bed reactor 100 were measured by the first and second differential pressure transducers 610 and 620 respectively, while increasing the pressure from an absolute pressure of 1 bar to 6 bar.

(68) FIG. 3 shows a graph for the test using a single pressure control valve according to the related art. FIG. 4 shows test result using a high pressure fluidized bed system according to an exemplary embodiment of the present invention.

(69) Firstly, described is the test result using a single pressure control valve according to the related art, referring to FIG. 3.

(70) A pressure in the interior of a fluidized bed reactor 100 was increased from 1 bar. If reaching 6 bar, such pressure was slightly decreased by opening a pressure control valve and then fluctuated for a certain period of time (See Section A), followed by controlled to 6 bar ultimately.

(71) A differential pressure in the interior of a fluidized bed fluctuated sharply (See Section B). If an inner pressure of the fluidized bed reached 6 bar, as the pressure control valve was opened, gas expanded rapidly, allowing sharply increasing values measured from a second differential pressure transducer 620 and a first differential pressure transducer 610. Such values fluctuated, followed by converged on values in a normal state (See Section C).

(72) Hereinafter, described is the test result using a high pressure fluidized bed system according to an exemplary embodiment of the present invention, referring to FIG. 4.

(73) A pressure of a fluidized bed reactor 100 was controlled by dual pressure control valves.

(74) A flow rate of a second valve 420 was half of a first valve 410.

(75) The second valve 420 was in a state of manually opened 30%.

(76) A pressure in the interior of a fluidized bed reactor 100 was increased from 1 bar. If reaching 6 bar, such pressure was slightly decreased by opening a pressure control valve and then controlled to 6 bar ultimately.

(77) If using the dual pressure control valves 400, it took a little more time to reach a desired pressure (6 bar), whereas fluctuation was decreased after reaching the desired pressure (Compare Section A).

(78) A differential pressure in the interior of a fluidization bed tended to show gradual increase and/or decrease while a pressure was increased (Compare Section B). After the inner pressure of the fluidization bed reached the desired pressure 6 bar, it was identified that a change in values measured by a second differential pressure transducer 620 and a first differential pressure transducer 610 was not great (Compare Section C).

REFERENCE NUMERALS

(79) 100: a fluidized bed reactor 200: a pressure sensor 300: a cyclone part 410: a first valve 420: a second valve 500: pressure transducer 610: a first differential pressure transducer 620: a second differential pressure transducer