Technical Field

[1] The present invention relates to a pneumatic pump system, and more particularly, to a pneumatic pump system that absorbs and discharges water inside a sump. Background Art

[2] A cargo warehouse "hold" in which cargos are loaded, is provided in a large-sized ship such as a cargo ship. The hold is open during cunstructing and a sump is provided in the cargo ship. Water filled in the sump can't be easily pumped and discharged. In addition, electricity is not used in a ship such as the cargo ship in danger of explosion or fire caused by a painting work during cunstructing. Thus, an pneumatic pump structure is used. However, when water filled in the sump rises above a predetermined water level, the water should be discharged at a good time, and a pump control system that is appropriate to discharging of water, is needed. Disclosure of Invention Technical Problem

[3] The present invention provides a pneumatic pump system in which, when water filled in a sump rises above a predetermined water level, an operation of a pneumatic pump is controlled to start so that water can be quickly discharged. Technical Solution

[4] According to an aspect of the present invention, there is provided a pneumatic pump system that discharges water inside a sump, the system including: a supply portion supplying air; a limit switch outputting air, supplied by the supply portion, to a first port as one of the first port and a second port when water inside the sump rises above a first predetermined water level; a timer resetting a predetermined amount of time by using air, output from the first port and supplied to a reset port, and waiting for driving of the predetermined amount of time; an air valve being open and allowing air, supplied by the supply portion, to pass through the air valve when air output from the first port is supplied to the air valve; and an pump driven by air that passes through the air valve and pumping water inside the sump.

[5] The limit switch may output air to the second port when water inside the sump falls below a second predetermined water level due to an operation of the pump, and the timer may start driving of the predetermined amount of time by using air, output from the second port and supplied to an input port, and the air valve may maintain the open state for the predetermined amount of time and may drive the pump one more time.

Advantageous Effects [6] As described above, in the pneumatic pump system according to the present invention, when water filled in a sump rises above a predetermined water level, an operation of an pump is controlled to start so that water can be quickly discharged. In addition, when the operation of the pump is performed one more time for a predetermined amount of time even after water filled in the sump falls below a predetermined water level due to the operation of the pump, a small amount of water that remains in the sump can be completely discharged. Brief Description of Drawings

[7] The above and other aspects of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings in which:

[8] FIG. 1 illustrates a structure of a pneumatic pump system according to an embodiment of the present invention;

[9] FIG. 2 illustrates control flow of pumping water when water inside a sump used in the pneumatic pump system of FIG. 1 rises above a first predetermined water level;

[10] FIG. 3 illustrates control flow of pumping water one more time for a predetermined amount of time when water inside the sump falls below a second predetermined water level due to FIG. 2;

[11] FIG. 4 illustrates control flow of stopping a pumping operation after a predetermined amount of time elapses in FIG. 3;

[12] FIG. 5 illustrates control flow of a manual mode in which water used in FIG. 1 is manually pumped;

[13] FIG. 6 is a detailed side view of a water inlet disposed in an inlet tube of the pneumatic pump system of FIG. 1 ; and

[14] FIG. 7 is a plan view of FIG. 6.

Best Mode for Carrying out the Invention

[15] FIG. 1 illustrates a structure of a pneumatic pump system 100 according to an embodiment of the present invention. Referring to FIG. 1, the pneumatic pump system 100 includes a supply portion 110, a limit switch 120, a timer 130, an air valve 140, and an pump 150.

[16] FIG. 2 illustrates control flow of pumping water when water inside a sump used in the pneumatic pump system 100 of FIG. 1 rises above a first predetermined water level. Referring to FIG. 2, the supply portion 110 is a portion to which air as a source for driving the pump 150 is supplied. The limit switch 120 outputs air supplied by the supply portion 110 to a first port A as one of the first port A and a second port B when water inside the sump rises above a first predetermined water level. Here, the limit switch 120 is operable using upward and downward displacement of a buoy 121 that is disposed due to buoyancy of water. However, the present invention is not limited to this, and the limit switch 120 may have other structures.

[17] The timer 130 resets a predetermined amount of time by using air, which is output from the first port A and is supplied to a reset port Yl, and waits for driving of the predetermined amount of time. When air output from the first port A is supplied to the air valve 140, the air valve 140 is open, and thus, air supplied by the supply portion 110 passes through the pump 150.

[18] Here, the pump 150 is driven by air that passes through the air valve 140 and pumps water inside the sump outside of the pump 150. In other words, the pump 150 absorbs water inside the sump through an inlet tube 151 and then discharges water through an outlet tube 152 outside of the pump 150.

[19] Meanwhile, when water inside the sump rises above the first predetermined water level, the pump 150 may operate, as described above, and when water falls below a second predetermined water level due to a pumping operation of the pump 150, the operation of the pump 150 may be stopped. However, for example, the limit switch 120 using buoyancy does not properly sense a small amount of water that remains in the sump, and water inside the sump is not completely discharged.

[20] FIG. 3 illustrates control flow of pumping water one more time for a predetermined amount of time when water inside the sump falls below a second predetermined water level due to FIG. 2. Referring to FIG. 3, the pneumatic pump system 100 drives the pump 150 one more time for the predetermined amount of time even after water inside the sump falls below the second predetermined water level. The structure causes the small amount of water that remains in the sump to be completely discharged.

[21] In other words, to this end, when water inside the sump falls below the second predetermined water level due to the operation of the pump 150, the limit switch 120 outputs air to the second port B. In this case, the timer 130 starts driving of the predetermined amount of time by using air, which is output from the second port B and is supplied to an input port Xl. Thus, the air valve 140 maintains the open state for the predetermined amount of time and drives the pump 150 one more time so that water that remains in the sump can be completely discharged.

[22] FIG. 4 illustrates control flow of stopping a pumping operation after a predetermined amount of time elapses in FIG. 3, and FIG. 5 illustrates control flow of a manual mode in which water used in FIG. 1 is manually pumped. Referring to FIG. 4, when driving of the predetermined amount of time is completed, the timer 130 outputs air, which is supplied by the supply portion 110 to a main port Pl, to an output port Al. In this case, the air valve 140 is closed when air output from the output port Al of the timer 130 is supplied to the air valve 140, so that air supplied by the supply portion 110 is intercepted and driving of the pump 150 is stopped. [23] Meanwhile, the pneumatic pump system 100 is operable in an automatic mode in which the operation of the pump 150 is automatically controlled by sensing a water level, as illustrated in FIGS. 2 through 4. In addition, the pneumatic pump system 100 is operable in a manual mode that is set by a user's manual work regardless of sensing a water level, as illustrated in FIG. 5. For this purpose, the pneumatic pump system 100 further includes a three-direction valve 160.

[24] The three-direction valve 160 includes a first flow path 161, a second flow path 162, and a third flow path 163. The first flow path 161 is a portion in which air supplied by the supply portion 110 flows. The second flow path 162 is a flow path in which air flowed in the first flow path 161 flows in the timer 130 and the air valve 140. The third flow path 163 is separated from the second flow path 162 and allows air flowed in the first flow path 161 to flow in the pump 150.

[25] In other words, connection between the first flow path 161 and the second flow path

162 (see FIGS. 2 through 4) of the three-direction valve 160 or connection between the first flow path 161 and the third flow path 163 (see FIG. 5) of the three-direction valve 160 may be variably performed by a user's manual work. More specifically, the three- direction valve 160 maintains the state of connection between the first flow path 161 and the second flow path 162 of the three-direction valve 160 during an automatic operation. When the state of the three-direction valve 160 is converted into the state of connection between the first flow path 161 and the third flow path 163 of the three- direction valve 160 by user's manipulation, as illustrated in FIG. 5, the three-direction valve 160 allows air, which is supplied by the supply portion 110, to flow in the pump 150 so that the pump 150 is manually operable.

[26] In other words, during the manual operation, the pump 150 is operable regardless of driving of the limit switch 120, the timer 130, and the air valve 140. The three- direction valve 160 may be operable by manipulation such as rotating of a valve performed by a user.

[27] FIG. 6 is a detailed side view of a water inlet disposed in an inlet tube of the pneumatic pump system 100 of FIG. 1, and FIG. 7 is a plan view of FIG. 6. Referring to FIGS, 1, 6, and 7, the pump 150 includes a water inlet 153 that is sunk in water inside the sump and absorbs water. Here, the pneumatic pump system 100 further includes an air jet tube 170 that jets air to an outside from an inside of the water inlet 153 by using air supplied by the supply portion 110 and cleans the water inlet 153. To this end, the water inlet 153 may be installed at an inside of the inlet tube 151, as illustrated in FIGS. 6 and 7.

[28] The air jet tube 170 is diverged between the air valve 140 and the pump 150, and air may be supplied to the air jet tube 170 from the supply portion 110. In this case, when the pump 150 operates, air is blown into the water inlet 153 so as to remove a foreign substance from the water inlet 153.

[29] Here, the water inlet 153 may be formed in the form of a net, so as to prevent the foreign substance inside the sump from being flowed in the water inlet 153. The present invention is not limited to this, and the water inlet 153 may have various net shapes as well as the honeycomb structure shown in FIG. 6. The air jet tube 170 removes the foreign substance from the water inlet 153 by blowing air into the water inlet 153 when the pump 150 operates. As such, the absorption operation of the water inlet 153 is more smoothly performed, and absorption efficiency is improved.

[30] Referring to FIGS. 6 and 7, the air jet tube 170 is installed along a lengthwise direction of the inlet tube 151, is curved and extends along an inside of a circumference of the water inlet 153. Here, a plurality of through holes 171 are formed in the air jet tube 170 along the lengthwise direction of the extending side surface of the air jet tube 170, and air is jetted through the through holes 171. The through holes 171 allow air to be uniformly jetted along the lengthwise direction of the extending side surface of the air jet tube 170 and cleaning efficiency of the water inlet 153 to be improved.

[31] The present invention can be used in an pump that discharges water inside a sump, as well as in a cargo ship.

[32] While this invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.