JP5674237B2 - centrifuge - Google Patents

Description

  The present invention relates to a centrifuge that rotates a rotating body (rotor) at a high speed, and more particularly to treatment of condensed water generated in a centrifuge provided with a cooling device for cooling the rotor.

  A centrifuge separates and purifies a sample by inserting a sample to be separated (for example, a culture solution or blood) into a rotor through a tube or a bottle and rotating the rotor at a high speed. The set rotational speed of the rotor varies depending on the application, and a product group from a low speed (about several thousand revolutions) to a high speed (the maximum rotational speed is 150,000 rpm) is provided according to the application. There are various types of rotors used in centrifuges. Angle rotors that can handle high rotation speeds with tube holes at fixed angles, and buckets loaded with tubes swing from a vertical state to a horizontal state as the rotor rotates. There is a moving swing rotor. In addition, there are rotors of various sizes such as a rotor that rotates at a very high rotation speed to apply a high centrifugal acceleration to a small amount of sample, and a rotor that can handle a large volume of sample at a low rotation speed. Since these rotors are used in accordance with the sample to be separated, the rotor is configured to be attachable to and detachable from a rotating shaft of driving means such as a motor, and the rotor can be replaced.

  When the rotor rotates at high speed in the air, the temperature of the rotor rises due to frictional heat with the air. Some samples to be separated must be kept at a low temperature, and therefore a centrifuge having a cooling device for cooling the rotor during operation is widely used. This centrifugal separator is provided with a cooling device (consisting of an evaporator, a compressor, a condenser, and an expansion valve) in the main body, and by flowing a refrigerant through a copper pipe wound around the bowl outer wall of the rotor chamber, the rotor chamber The rotor is cooled by this cooling.

  After the centrifuge operation, if the door that closes the rotor chamber opening is opened to take out the separated sample, warm air flowing from the outside touches the cooled rotor or bowl, and condensation occurs on the surface of the bowl. Sometimes. This condensed water is gradually accumulated at the bottom of the bowl by repeating the centrifugal separation operation. Therefore, in Patent Document 1, a drain tube is attached to the bottom surface of the bowl, and the drain tube is connected to the outside of the centrifuge main body so that the condensed water generated in the rotor chamber can be discharged out of the rotor chamber. The opening of the drain tube drawn out of the centrifuge is closed with a cap or a cock, and when the condensed water has accumulated in the drain tube to some extent, the user removes the cap and drains the condensed water. The amount of condensed water varies depending on the surrounding environment, operating conditions, etc., but the user performs an operation of draining condensed water at a frequency of about once / several days to once / several weeks, for example. If the condensed water does not come out even if it accumulates, the condensed water stays in the rotor chamber (bottom of the bowl) and may start to solidify on the inner wall of the bowl, which may reduce the cooling capacity of the rotor.

  Here, the structure of a conventional centrifuge will be described with reference to FIG. The centrifuge 101 is provided with a bowl 102 inside a housing 106 made of a box-shaped sheet metal or the like. The bowl 102 and the door 5 define a rotor chamber 103. The door packing 16 seals the rotor chamber 103. The The rotor 4 holds a sample to be separated and rotates at a high speed. For example, a plurality of holes (not shown) for inserting a sampling tube or the like into which the sample is inserted are formed and supported by the rotating shaft of the motor 8. The rotor 4 is rotated by the motor 8, and the rotation of the motor 8 is controlled by the control device 118. The door 5 can be opened and closed by rotating up and down about the hinge 15 as a central axis. Behind the door 5 is arranged an operation panel 17 for displaying various information while the user inputs conditions such as the rotational speed and separation time of the rotor.

  The rotor chamber 103 is configured such that the upper opening can be sealed by the door 5, and the rotor 4 can be attached to or detached from the rotor chamber 103 with the door 5 opened. A copper pipe 7 c is spirally wound around the outer periphery of the bowl 102, and the outer periphery of the copper pipe 7 c is surrounded by a cylindrical heat insulating material 14. A cooling device including a condenser 7a and a compressor 7b and a fan 20 for radiating heat are disposed in the lower part of the main body, and a copper pipe 7c is connected to the compressor 7b. When the refrigerant is sent from the compressor 7b to the condenser 7a, the refrigerant is cooled and liquefied. The liquefied refrigerant is supplied to the copper pipe 7c through the capillary 7d, and the bowl 102 is cooled by evaporating the refrigerant in the copper pipe 7c, and the interior of the rotor chamber 103 is maintained at a set desired temperature. . The operation of the cooling device is controlled by the control device 118, and the temperature of the rotor 4 is monitored by the control device 118 using the output of a temperature sensor (not shown) installed in the rotor chamber 103. Further, a metal drain pipe 111 is connected to the bottom of the bowl 102 to discharge condensed water in the rotor chamber 103, and a flexible drain tube 110 made of vinyl or the like is attached to the drain pipe 111. One end of the drain tube 110 on the opposite side to the rotor chamber 103 is pulled out to the outside (outside the machine) of the centrifuge 101, and the opening of the drain tube 110 on the side opposite to the drain pipe 111 is sealed with a cap 112.

  The centrifuge 101 is provided with a brake resistor 135 in order to give a braking action when the rotor 4 is decelerated. The brake resistor 135 stops supplying power to the motor 8 when the rotor 4 decelerates, operates the motor 8 as a generator, and consumes the regenerative energy (electric power) generated by the brake resistor 135 to rotate the motor 8. Resistance is generated to obtain braking force. The electric power flowing through the brake resistor 135 is converted into heat, and the performance of the braking force of the rotor 4 varies depending on the capacity of the brake resistor 135. The brake resistor 135 that generates heat is disposed so that its heat radiating surface is in close contact with the mounting surface 106 d formed on the housing 106, and releases heat to the housing 106. The wind taken from the slit 106a by the blower 20 passes through the condenser 7a, cools the compressor 7b and the brake resistor 135, and then is discharged from the slit 106b to the outside of the centrifuge 101.

JP 2006-346617 A JP 2003-172576 A

  The conventional centrifuge 101 has a troublesome aspect because it is necessary for an operator to periodically drain the condensed water accumulated in the drain tube 110. In order to eliminate such manual drainage of the condensed water, in the refrigerator field as shown in Patent Document 2, the condensed water generated in the refrigerator is dropped on the evaporating dish, and the compressor and the condenser pipe heat There is known a method of evaporating condensed water by using the water. However, in the case of a centrifuge, since the centrifuge may vibrate greatly when an excessive imbalance occurs in the rotor, there is a possibility that condensed water may be scattered on the compressor or the condensation pipe. It is not preferable to arrange it in the evaporating dish so as to be in contact with the condensation pipe. In the centrifugal separator, the cooling device is not always operated, but only operated when the rotor 4 is rotated. The technique of Patent Document 2 is applied as it is so that the evaporating dish is in contact with the compressor and the condensation pipe. Even so, there was a problem that sufficient heat could not be applied to the evaporating dish.

  The present invention has been made in view of the above background, and its purpose is to provide a centrifugal separator that can effectively drain and evaporate the condensed water generated in the rotor chamber and realizes maintenance-free of condensed water management. It is to provide.

  Another object of the present invention is to provide a centrifuge capable of evaporating condensed water using regenerative energy during deceleration.

  Still another object of the present invention is to provide a centrifuge which can be controlled so as to freely heat the evaporating dish by causing a current to flow through the brake resistor in accordance with the amount of accumulated condensed water.

  The characteristics of representative ones of the inventions disclosed in the present application will be described as follows.

  According to one aspect of the present invention, a motor, a rotor attached to the rotating shaft of the motor, a bowl forming a rotor chamber that houses the rotor, a door that closes the opening of the bowl, and the rotation of the motor are controlled. Control device, cooling device for cooling the rotor chamber, drain for discharging condensed water in the bowl, and a centrifugal separator having brake resistance that consumes regenerative energy generated when the rotor is decelerated. An evaporating dish for receiving condensed water is provided, the evaporating dish is fixed so that the brake resistance is in close contact with the evaporating dish, and the evaporating dish is heated by heat generated from the brake resistance. The drain is provided with a valve that can be switched between open and closed, and the control device controls the discharge of condensed water from the drain to the evaporating dish by controlling the opening and closing of the valve. The control device controls opening and closing of the valve according to the operating state of the rotor.

According to another aspect of the present invention, the evaporating dish is provided with a water level sensor, and the controller supplies power to the brake resistor regardless of the rotor deceleration timing when the water level sensor detects that the predetermined amount of water has been reached. To do. The cooling device has a blower, an evaporating dish was placed in a position to be exposed to the blowing of the blower. In addition, a blower for cooling the motor may be provided, and the evaporating dish may be disposed at a position exposed to the blower of the blower. The evaporating dish is provided on the upper side, the lower side, or the space protruding downward from the bottom surface of the centrifuge housing.

  According to still another aspect of the present invention, the evaporating dish is made of metal and has a flat flat portion at the center, and a gentle slope is formed around the flat portion toward the outer peripheral surface, so that the brake resistance Is in close contact with the lower portion of the flat portion. In addition, the evaporating dish is made of metal and has a flat portion that is raised at the center, a gentle slope is formed from the periphery that has dropped from the flat portion toward the outer periphery, and the brake resistance is raised. You may form so that it may contact | adhere to the lower part of this.

  According to the first aspect of the present invention, since the evaporating dish for receiving the condensed water discharged from the drain for discharging the condensed water in the bowl is provided, the condensed water in the rotor chamber can be stored. In addition, it is fixed so that the brake resistance is in close contact with the evaporating dish, and the regenerative energy generated when the rotor is decelerated is consumed in the brake resistance to heat the evaporating dish and evaporate the condensed water. In addition, it is not necessary to remove condensed water from the drain, and a centrifuge that is easy to use can be provided. Further, by using the brake resistance conventionally provided in the centrifuge for heating the evaporating dish, there is no special cost increase, and the condensed water can be evaporated with a simple configuration.

  According to the invention of claim 2, since the drain is provided with a valve that can be switched between open and closed, and the drainage of the condensed water is automatically discharged by controlling the opening and closing of the valve, the operator considers the timing of draining the condensed water from the drain. Therefore, it is possible to realize an easy-to-use centrifuge.

  According to the invention of claim 3, since the control device controls the opening and closing of the valve according to the operating state of the rotor, the rotor chamber and the outside are in communication with each other during the rotation of the rotor, so that air enters and exits. This can prevent problems such as a decrease in the cooling temperature of the rotor chamber and wind noise.

  According to the invention of claim 4, the evaporating dish is provided with a water level sensor, and the control device supplies power to the brake resistor regardless of the rotor deceleration timing when the water level sensor detects that the water level has reached a predetermined level. Therefore, the evaporating dish can be freely heated, and it is possible to cope with an increase in the amount of condensation.

According to the invention of claim 5, the cooling device has a blower, since the evaporating dish is placed in a position which is exposed to the cooling air generated by the blower, the evaporation of condensed water collected in the evaporating water Can be promoted.
According to the invention of claim 6, the blower for cooling the motor is provided, and the evaporating dish is disposed at a position exposed to the cooling air generated by the blower, so that the condensed water accumulated in the evaporated water is evaporated. Can be promoted.

According to the invention of claim 7 , since the evaporating dish is provided at the lower part of the bottom surface of the centrifuge housing, not only can the cooling air from the blower be easily guided, but even if water leaks from the evaporating dish. It is possible to prevent other devices from being affected.

According to the eighth aspect of the present invention, the evaporating dish is made of metal and has a flat flat portion at the center, a gentle slope is formed around the flat portion toward the outer peripheral surface, and the brake resistance is flat. Since it adheres closely to the lower part of the part, the heat of the brake resistance can be effectively dissipated by the evaporating dish, and the evaporation of the condensed water can be promoted. Moreover, since the dew condensation water discharged | emitted from a drain falls on the inclined surface of an evaporating dish and is collected by the center part of an evaporating dish, it can suppress that the water | moisture content which vaporized returns to a drain.

According to the invention of claim 9 , the evaporating dish is made of metal and is formed with a flat portion that is raised at the center, and a gentle slope is formed toward the outer peripheral surface from the periphery that has fallen downward from the flat portion, Since the brake resistance is in close contact with the lower portion of the raised flat portion, the heat of the brake resistance can be effectively dissipated by the evaporating dish, and evaporation of condensed water can be promoted. Moreover, since the raised flat part for accommodating the brake resistance is provided at the center of the evaporating dish, it is possible to prevent the evaporating dish from increasing in height, and to install the evaporating dish in a space restricted in the height direction. Can do.

  The above and other objects and novel features of the present invention will become apparent from the following description and drawings.

It is sectional drawing which shows the whole structure of the centrifuge 1 which concerns on the Example of this invention. It is a perspective view which shows the shape of the evaporating dish 30 of FIG. It is sectional drawing of the evaporating dish 30 of FIG. It is a figure which shows the electricity supply timing to the brake resistor 35 of the centrifuge 1 which concerns on the Example of this invention, and the opening / closing timing of the valve | bulb 19. FIG. It is a figure which shows the relationship between the energization timing to the water level sensor 37 and the brake resistor 35 of the centrifuge 1 which concerns on the Example of this invention. It is sectional drawing which shows the structure of the evaporating dish 40 which concerns on the modification of a 1st Example. It is sectional drawing which shows the structure of the centrifuge 51 which concerns on the 2nd Example of this invention. It is sectional drawing which shows the structure of the conventional centrifuge 101. FIG.

  Embodiments of the present invention will be described below with reference to the drawings. In the following drawings, the same portions are denoted by the same reference numerals, and repeated description is omitted. Further, in this specification, description will be made assuming that the front-rear and up-down directions are the directions shown in FIG.

  FIG. 1 is a cross-sectional view showing the overall structure of a centrifuge 1 according to an embodiment of the present invention. In the centrifuge 1, a bowl 2 is provided inside a housing 6 made of a box-shaped sheet metal or the like, the rotor chamber 3 is defined by the bowl 2 and the door 5, and the rotor chamber 3 is sealed by a door packing 16. The The rotor 4 holds the sample to be separated and rotates at a high speed, and is supported by the rotating shaft of the motor 8. The rotor 4 is rotated by a motor 8, and the rotation of the motor 8 is controlled by a control device 18. The door 5 can be rotated in the vertical direction about the hinge 15 as a central axis. On the side of the door 5, an operation panel 17 for displaying various information while a user inputs conditions such as the rotational speed and separation time of the rotor is disposed.

  The rotor chamber 3 is configured such that the upper opening can be sealed by the door 5, and the rotor 4 can be attached to or detached from the rotor chamber 3 with the door 5 opened. A copper pipe 7 c is spirally wound around the outer periphery of the bowl 2, and the outer periphery of the copper pipe 7 c is surrounded by a cylindrical heat insulating material 14. The copper pipe 7c is connected to a cooling device, the refrigerant is sent from the compressor 7b into the condenser 7a, and the refrigerant cooled by the condenser 7a and the blower 20 is liquefied. The liquefied refrigerant is supplied to the copper pipe 7c through the capillary 7d, and the inside of the rotor chamber 3 is kept constant at a desired temperature set by the control of the control device 18 during the centrifugal separation operation. The temperature of the rotor 4 is monitored by the control device 18 using the output of a temperature sensor (not shown) installed in the rotor chamber 3. Further, a drain (drainage means) is provided at the bottom of the bowl 2 in order to discharge condensed water in the rotor chamber 3. The drain of the present embodiment includes a metal drain pipe 11 and a flexible drain tube 10 made of vinyl or the like connected to the drain pipe 11. The drain configuration is not limited to such a configuration, and may be realized by other known discharge paths and discharge mechanisms.

  In the centrifuge 1 according to the present embodiment, the evaporating dish 30 is provided at the bottom of the housing 6. In this embodiment, in order to fix the evaporating dish 30, the evaporating dish storage chamber 12 that protrudes downward from the bottom of the housing 6 by about the height of the evaporating dish 30 is formed. The size of the evaporating dish storage chamber 12 is slightly larger than the evaporating dish 30 and is preferably a semi-enclosed space in which three side surfaces except the rear side surface are closed. A through hole 6d through which the drain tube 10 passes is formed in the upper part of the semi-enclosed space, and the lower end portion of the drain tube 10 passes through the through hole 6d and extends to the internal space below the opening of the evaporating dish 30. Be placed. The evaporating dish storage chamber 12 may be formed of sheet metal in the same manner as the housing 6, or may be manufactured separately from a synthetic resin such as plastic and attached to the housing 6. The evaporating dish 30 has a flat surface at the center bottom, and has a dish-side shape having a sloped part around the flat surface, and the condensed water discharged from the drain tube 10 falls onto the sloped surface of the sloped part, It is effectively collected in the central part of the evaporating dish 30. Thus, by shifting the position of the drain opening of the drain tube 10 and the plane of the central bottom of the evaporating dish 30, it is possible to effectively eliminate the moisture evaporated in the evaporating dish 30 from returning to the drain tube 10 again. it can.

  An electromagnetic valve 19 is provided between the drain pipe 11 and the lower end of the drain tube 10. The opening and closing of the valve 19 can be controlled by the control device 18. Normally, if the valve 19 is open while the rotor 4 is rotating at high speed, the rotor chamber 3 is in communication with the outside, and air enters and exits, resulting in a decrease in the cooling temperature of the rotor chamber 3 and wind noise. There are problems such as sticking to the ears, which is not preferable. Therefore, in this embodiment, the control device 18 controls the valve 19 so as to repeatedly open in a short time at regular intervals, or to control the valve 19 to be opened only when the rotor 4 is stopped. Or is controlled so as to be opened only at the time of low speed during acceleration / deceleration of the rotor 4 or during deceleration. Thus, the valve 19 is appropriately controlled to open and close by the control of the control device 18.

  The bottom edge of the edge portion behind the through-hole 6d of the housing 6 is bent obliquely upward so that a part of the wind of the blower 20 indicated by an arrow in the figure is guided into the evaporating dish storage chamber 12. Composed. Since this air is warmed air that has passed through the condenser 7a, evaporation of the condensed water can be promoted by touching the condensed water. Since the evaporating dish 30 is configured to have a high flatness and a large water surface area, evaporation of the condensed water accumulated in the evaporating dish 30 is promoted. As described above, in this embodiment, a part of the wind of the blower 20 arranged for cooling the condenser 7a and the compressor 7b, which are components of the cooling device 7, is transferred to the evaporating dish storage chamber 12 by the guide 13. Since it is configured to guide and take in and to flow outside through the upper part of the water surface accumulated in the evaporating dish 30, it is not necessary to provide a new blowing means, and an increase in cost can be suppressed.

  Next, the structure of the evaporating dish 30 will be described with reference to FIGS. 2 and 3. FIG. 2 is a perspective view of the evaporating dish 30, and FIG. 3 is a longitudinal sectional view of the evaporating dish 30. The evaporating dish 30 is a thin metal container, for example, a stainless steel container, and has a rectangular shape when viewed from above. This shape may be an arbitrary shape as long as the size corresponds to the size of the brake resistor 35 attached to the lower side of the evaporating dish 30. The evaporating dish has a rectangular bottom portion 34 to be a surface to which the brake resistor 35 is attached, and is connected to slope portions 33 (33a to 33d) extending obliquely in four directions from the outer periphery of the bottom portion 34. Four wall portions 32 (32a to 32d) extending upward from the outer peripheral portion of the slope portion 33 are formed. Above the wall 32 is an opening 31. The height of the four wall portions 32a to 32d may be set according to the amount of dew condensation water that is assumed, but the wall portions 32a to 32d may not be provided when the dew condensation water is low. Moreover, when the dew condensation water is likely to spill due to vibration of the centrifuge 1, the walls 32a to 32d may be set higher.

  A brake resistor 35 is fixed to the lower surface of the bottom 34 of the evaporating dish 30 so as to be in close contact therewith. This fixing method may be fixed with an adhesive, a double-sided tape, or may be fixed with a screw or the like, but a joining method that improves the thermal conductivity from the brake resistor 35 to the evaporating dish 30 is used. It is good to use. A wiring 36 extending from the brake resistor 35 is connected to the motor 8 via switching means (not shown). Since the evaporating dish 30 is composed of a metal plate having excellent heat dissipation characteristics, the evaporating dish 30 itself can function as a heat radiating plate for the brake resistor 35. The evaporating dish 30 is preferably fixed by floating from the evaporating dish storage chamber 12 for the purpose of transmitting heat generated by the brake resistor 35 to the evaporating dish 30 as much as possible and not to the housing 6. In this embodiment, the brake resistor 35 and the evaporating dish 30 are configured so that only a small point contacts the bottom surface of the evaporating dish storage chamber 12.

  Although the center part (bottom part 34 mentioned later) of the evaporating dish 30 is flat, the outer peripheral side becomes a surface with a gentle inclination like a mortar shape. The condensed water that has fallen to any position of the evaporating dish 30 is guided to the bottom 34 by the slope 33. Therefore, condensed water is collected on the heat radiation surface heated by the brake resistor 35, that is, the bottom 34. In this state, when electric power is supplied to the brake resistor 35, the brake resistor 35 generates heat and the evaporating dish 30 is heated, so that evaporation of condensed water is promoted.

  A water level sensor 37 is attached to a part of the side surface of the evaporating dish, specifically near the center of the wall 32d. The water level sensor 37 is a sensor for detecting that a certain amount of condensed water has accumulated in the evaporating dish. When the condensed water touches the water level sensor 37, the output signal of the water level sensor 37 changes. For example, a thermistor can be used as the water level sensor 37. By sending the output change of the thermistor to the control device 18, the control device 18 can detect that the condensed water has accumulated in the evaporating dish 30. The water level sensor 37 is not limited to a thermistor, and a float type liquid level sensor (not shown) or other known water level sensor can be used.

  Electric power is supplied to the brake resistor 35 mainly by regenerative energy when the rotor 4 is decelerated. This principle is also called a power generation brake. When the motor 8 decelerates, the rotational force of the rotor 4 is used as an input to operate the motor 8 as a generator, thereby improving the brake performance and effectively utilizing the regenerated energy. To do. The generated electric power is energized to the brake resistor 35, and the brake resistor 35 generates heat to consume electricity. The braking force at this time varies depending on the resistance value and capacity of the brake resistor 35.

  In this embodiment, the power applied to the brake resistor 35 is configured not only to regenerate energy but also to power from a commercial power source. For example, when the control device 18 detects the full state of the dew condensation water based on the output signal of the water level sensor 37, the control device 18 freely controls the power applied to the brake resistor 35, so that the dew condensation water accumulated in the evaporating dish 30 can be reduced. Any timing can be evaporated. By controlling in this way, it is possible to control the condensed water to evaporate regardless of the operating state of the rotor 4. In order to evaporate the condensed water while the rotation of the rotor 4 is stopped, the blower 20 may be operated in addition to energizing the brake resistor 35.

Next, the energization timing to the brake resistor 35 and the opening / closing timing of the valve 19 will be described with reference to FIGS. 4 and 5. FIG. 4 is a diagram showing energization timing to the brake resistor 35 and opening / closing timing of the valve 19 of the centrifuge 1 according to the embodiment of the present invention. The horizontal axis of each graph is time t (seconds), and the horizontal axis of each graph is aligned. The uppermost graph is a graph showing the number of rotations of the rotor 4, and this figure shows a situation where the centrifugal separation operation is performed three times. The first rotation of the rotor 4 starts acceleration from time 0, reaches the set rotational speed N ₁ at time t ₁ and operates at a constant speed for a fixed time, and then starts to decelerate the rotor 4 from time t ₂ to time t ₃ shows a state in which the rotation of the rotor 4 is stopped. Here, the center graph shows the timing of energization to the brake resistor 35. When the brake is "ON", the brake current is energized to the brake resistor 35. When the brake is "OFF", the motor 8 and the brake resistor 35 are cut off. Indicates that

As it can be seen in comparison with the rotational speed of the graph of the rotor 4, the to the brake resistor 35, when the rotor 4 is decelerated, i.e. is energized only during the time t ₂ of t _3. This is because the brake resistor 35 when the regenerative energy is used can be energized only when the motor 8 is braked. The valve 19 from time _{t 2} to _{t 4} in the open state. In other words, the valve 19 is closed when the rotor 4 is accelerated and operated at a normal rotational speed. This is because if the valve 19 is opened while the rotor 4 is rotating, the rotor chamber 3 and the outside are in communication with each other, and air enters and exits, and the cooling temperature of the rotor chamber 3 is lowered and wind noise is heard. This is because problems such as sticking occur.

Similarly, only the interval t ₇ from the time t ₆ to perform deceleration of the rotor 4 energization of the brake resistor 35 is performed. The valve 19 is opened only during the time _{t 6} of time _{t 8.} Thus, by controlling the energization of the brake resistor 35 and the opening / closing operation of the valve 19 to synchronize with the rotation state of the rotor 4, it is possible to automate the discharge of condensed water from the drain tube 10 to the evaporating dish 30 and evaporate. It is possible to promote evaporation of the condensed water discharged to the dish 30.

  If the condensed water discharged to the evaporating dish 30 is insufficiently evaporated and the condensed water has accumulated until it comes into contact with the water level sensor 37, the control device 18 controls the power from the commercial power source. Can be added to the brake resistor 35 to heat the evaporating dish and promote the vaporization of condensed water. FIG. 5 is a diagram showing a relationship between energization timings of the water level sensor 37 and the brake resistor 35 of the centrifuge 1 according to the embodiment of the present invention. The opening / closing timing of the valve 19 needs to be controlled in conjunction with the rotation timing of the rotor 4, and the valve 19 cannot be opened / closed during acceleration or low speed operation of the rotor 4. However, energization timing to the brake resistor 35 can be arbitrarily energized except when the rotor 4 is decelerated.

Figure 5 is a graph of when the power supply to the brake resistor 35 as performed in conjunction with the water level sensor 37, the signal is ON state of the water level sensor 37 at time t _11, i.e., the water level of the condensed water level sensor When it is detected that the current reaches 37, a predetermined current is supplied from the commercial power source to the brake resistor 35. The time during which this current flows is the time t ₁₃ when a predetermined time T has elapsed from the time t ₁₂ when it is detected that the output signal of the water level sensor 37 is in an OFF state, that is, the water level of the condensed water is equal to or lower than the water level sensor 37. Continue until. This time T may be set according to the time when evaporation of condensed water in the evaporating dish is completed by passing a current through the brake resistor 35, and is set by the control device 18.

The control device may appropriately set the time T to be variable according to the temperature or the like. Note that when the rotor 4 is decelerated during the time t ₁₁ to t ₁₃ during which current is supplied to the brake resistor 35, the control device 18 stops the power supply from the commercial power source to the brake resistor 35. The current generated by the motor 8 may be switched to flow through the brake resistor 35. When the rotation of the rotor 4 stops, the control device 18 again starts supplying power from the commercial power source to the brake resistor 35.

  As described above, in this embodiment, the dew condensation water generated in the rotor chamber 3 is accumulated in the evaporating dish 30 from the drain, and the regenerative energy generated when the rotor decelerates on the brake resistor 35 in close contact with the evaporating dish 30. Since the evaporating dish 30 is heated and the condensed water is evaporated, there is no need to remove the condensed water from the conventional drain tube, and an easy-to-use centrifuge can be provided. Further, by using the brake resistor 35 that has been conventionally provided in the centrifugal separator, it is possible to prevent a special increase in cost, and it is possible to realize a dew condensation water evaporation mechanism with a simple configuration. Furthermore, by using the brake resistor 35 as a heat source applied to the evaporating dish 30, the evaporating dish 30 can be freely heated by passing an electric current regardless of the timing when the rotor 4 is decelerated, and the amount of condensation increases. It becomes possible to cope with time.

  It should be noted that the shape of the evaporating dish 30 can be realized in other shapes regardless of the shapes described in FIGS. FIG. 6 is a cross-sectional view showing the structure of the evaporating dish 40 according to a modification of the first embodiment. The evaporating dish 40 has a low height which is effective when the height of the evaporating dish storage chamber 12 is limited. It is. When limiting the height of the evaporating dish 40, it is preferable that the evaporating dish 40 is raised at the center by an area corresponding to the size of the brake resistor 45, and the brake resistor 45 is stored in a space secured by the elevating. . At this time, in order to improve heat conduction from the brake resistor 45 to the evaporating dish 40, a metal plate 48 of the same material as the evaporating dish 40 is disposed on the opposite surface of the evaporating dish 40. The brake resistor 45 is sandwiched. With this configuration, the brake resistor 45 can be attached to the evaporating dish 40 while suppressing the height of the evaporating dish 40.

  A flat surface portion 44 is formed inside the raised portion 44a of the evaporating dish 40, but a slope portion 43 that gently slopes outward is formed around the raised portion 44a that falls downward from the flat surface portion 44. Is done. A wall portion 42 extending upward from the outer peripheral portion of the slope portion 43 is formed, and a water level sensor 47 is provided on the wall portion 42. Above the wall 42 is an opening 41. In this modification, the shape and size of the opening 41 are the same as those of the opening 31 (see FIG. 3), but the shape of the evaporating dish 40 itself is not necessarily rectangular when viewed from above, and is oval. Or any other shape.

  Next, the structure of the centrifuge 51 according to the second embodiment of the present invention will be described with reference to FIG. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and repeated description thereof is omitted. The difference in the second embodiment is the installation location of the evaporating dish 30. In the second embodiment, the evaporating dish 30 having the same configuration as that described with reference to FIGS. 2 and 3 is provided in the vicinity of the motor 8 so that the evaporating dish storage chamber 62 is located near the center of the casing 56 in the vertical direction. Was provided. The evaporating dish storage chamber 62 is provided as a storage space for the motor 8 and is a closed space except for the installation position of the blower 70, the slit 56c, and the through hole 56d. A blower 70 is provided near the motor 8 in the evaporating dish storage chamber 62, and the motor 8 is cooled by the blower 70. The cooling air heated by cooling the motor 8 flows in the direction of the evaporating dish 30 close to the motor 8. For this reason, the cooling air is guided to the surface of the condensed water accumulated in the evaporating dish 30, thereby promoting the vaporization of the condensed water.

  The evaporating dish 30 is positioned such that the opening of the drain tube 60 faces the evaporating dish 30. The opening of the drain tube 60 is preferably arranged so as to oppose the inclined surface portion of the evaporating dish 30. An electromagnetic valve 69 is provided between the drain pipe 61 and the lower end of the drain tube 60. The valve 69 can be opened and closed under the control of the control device 18. In the second embodiment, the air sucked from the slit 56 a using the blower 20 is sucked into the evaporating dish storage chamber 62 by the further blower 70. And since it comprised so that the air warmed by passing the motor 8 might be guide | induced to the evaporating dish 30, dew condensation water can be evaporated effectively. The wind that has flowed through the top of the evaporating dish 30 is discharged to the outside through a slit 56 c provided on the side of the housing 56. The evaporating dish 30 is placed on the bottom surface of the evaporating dish storage chamber 62 with a heat insulating member 71 interposed therebetween. The reason why the heat insulating member 71 is used in this way is to transmit heat generated by the brake resistor 35 only to the evaporating dish 30 as much as possible so that heat is not conducted to the housing 56 side. Note that it is preferable that the evaporating dish storage chamber 62 has a semi-waterproof structure so that even if condensed water is scattered from the evaporating dish 30 due to vibration or the like, the scattered water stops in the evaporating dish storage chamber 62.

  As mentioned above, although this invention was demonstrated based on the Example, this invention is not limited to the above-mentioned Example, A various change is possible within the range which does not deviate from the meaning. For example, the material of the evaporating dish is not only made of metal as in the above-described embodiment, but may be made of a polymer resin such as plastic or other materials. The shape of the evaporating dish is not limited to a shallow rectangular dish, but may be other shapes.

DESCRIPTION OF SYMBOLS 1 Centrifuge 2 Bowl 3 Rotor chamber 4 Rotor 5 Door 6 Case 6a, 6b Slit 6d Through hole 7 Cooling device 7a Condenser 7b Compressor 7c Copper pipe 7d Capillary 8 Motor 10 Drain tube 11 Drain pipe 12 Evaporating dish storage chamber 13 Guide 14 Heat insulating material 15 Hinge 16 Door packing 17 Operation panel 18 Control device 19 Valve 20 Blower 30 Evaporating dish 31 Opening 32 Wall part 33 Slope part 34 Bottom part 35 Brake resistance 36 Wiring 37 Water level sensor 40 Evaporating dish 41 Opening 42 Wall part 43 Slope portion 44 Bottom portion 44a Raised portion 45 Brake resistance 47 Water level sensor 48 Metal plate 51 Centrifuge 56 Housing 56a to 56c Slit 56d Through hole 60 Drain tube 61 Drain pipe 62 Evaporating dish storage chamber 69 Valve 70 Blower 71 Heat insulation member 101 Far Center separator 102 Bowl 103 Rotor chamber 106 Housing 106a, 106b Slit 106d Placement surface 110 Drain tube 111 Drain pipe 112 Cap 118 Controller 118 Brake resistance

Claims (9)

A motor, a rotor attached to a rotation shaft of the motor, a bowl forming a rotor chamber for housing the rotor, a door for closing an opening of the bowl, a control device for controlling rotation of the motor, In a centrifuge having a cooling device that cools the rotor chamber, a drain that discharges condensed water in the bowl, and a brake resistor that consumes regenerative energy generated when the rotor is decelerated,
Providing an evaporating dish for receiving condensed water discharged from the drain;
The centrifugal separator is fixed so that the brake resistance is brought into close contact with the evaporating dish. Provide a valve that can be opened and closed in the drain,
The centrifuge according to claim 1, wherein the control device controls discharge of condensed water from the drain to the evaporating dish by controlling opening and closing of the valve. The centrifuge according to claim 2, wherein the controller controls the valve to be closed during acceleration and constant speed rotation of the rotor and to open the valve during deceleration of the rotor . The centrifuge according to claim 2 or 3, wherein a water level sensor is provided in the evaporating dish, and the control device supplies power to the brake resistor when it is detected by the water level sensor that a predetermined amount of water has been reached. Separator. Before SL cooling device has a blower,
The said evaporating dish is arrange | positioned in the position exposed to the ventilation of the air blower of the said cooling device, The centrifuge of Claim 4 characterized by the above-mentioned. Providing a blower for cooling the motor;
The centrifuge according to claim 4, wherein the evaporating dish is disposed at a position exposed to air from a blower for cooling the motor.   The centrifuge according to claim 5, wherein the evaporating dish is provided at a lower portion of a bottom surface of a housing of the centrifuge. The evaporating dish is made of metal and a flat flat portion is formed at the center, and a gentle slope is formed around the flat portion toward the outer peripheral surface.
The centrifuge according to claim 6 or 7 , wherein the brake resistance is in close contact with a lower portion of the flat portion. The evaporating dish is made of metal and has a flat portion raised at the center, and a gentle slope is formed from the periphery that has fallen downward from the flat portion toward the outer peripheral surface,
The centrifuge according to claim 6 or 7 , wherein the brake resistance is in close contact with a lower portion of the raised flat portion.

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