Oil Feed Type Compressor

Abstract

An oil feed type compressor includes a compressor body (2) that compresses a gas while oil is being injected therein, a first oil separator (6) that separates oil from the compressed gas delivered from the compressor body (2), a second oil separator (8) that further separates oil from the compressed gas from which the oil has been separated by the first oil separator (6), the second oil separator (8) having a reservoir (8bd) for storing the separated oil, a delivery pipe system (90) through which the compressed gas from which the oil has been separated by the second oil separator (8) flows, an oil discharge passage (10) that discharges the oil having been stored in the reservoir (8bd) from the reservoir (8bd), a valve body (10a) included in the oil discharge passage (10), and a controller (11) that controls the opening of the valve body (10a) over time.

1 . An oil feed type compressor comprising:
 a compressor body that compresses a gas while oil is being injected therein;   a first oil separator that separates oil from the compressed gas delivered from the compressor body;   a second oil separator that further separates oil from the compressed gas from which the oil has been separated by the first oil separator, the second oil separator having a reservoir for storing the separated oil;   a delivery pipe system through which the compressed gas from which the oil has been separated by the second oil separator flows;   an oil discharge passage that discharges the oil having been stored in the reservoir from the reservoir;   a valve body included in the oil discharge passage; and   a controller configured to control an opening of the valve body over time.   
     
     
         2 . An oil feed type compressor comprising:
 a compressor body that compresses a gas while oil is being injected therein;   a first oil separator that separates oil from the compressed gas delivered from the compressor body;   a second oil separator that further separates oil from the compressed gas from which the oil has been separated by the first oil separator, the second oil separator having a reservoir for storing the separated oil;   a delivery pipe system through which the compressed gas from which the oil has been separated by the second oil separator flows;   an oil discharge passage that discharges the oil having been stored in the reservoir from the reservoir;   a valve body included in the oil discharge passage; and   a controller configured to control an opening of the valve body on a basis of a load ratio and operating time of the compressor body.   
     
     
         3 . An oil feed type compressor comprising:
 a compressor body that compresses a gas while oil is being injected therein;   a first oil separator that separates oil from the compressed gas delivered from the compressor body;   a second oil separator that further separates oil from the compressed gas from which the oil has been separated by the first oil separator, the second oil separator having a reservoir for storing the separated oil;   a delivery pipe system through which the compressed gas from which the oil has been separated by the second oil separator flows;   an oil discharge passage that discharges the oil having been stored in the reservoir from the reservoir;   a valve body included in the oil discharge passage;   a pressure sensor that detects a pressure in the delivery pipe system; and   a controller that controls an opening of the valve body over time, wherein   the controller configured to control a timing to constrict the opening of the valve body on a basis of the pressure detected by the pressure sensor while the valve body is being open.   
     
     
         4 . The oil feed type compressor according to  claim 1 , wherein
 the controller repeatedly keeps the valve body at a first opening during a first period and keeps the valve body at a second opening larger than the first opening during a second period after elapse of the first period.   
     
     
         5 . The oil feed type compressor according to  claim 4 , wherein
 the controller closes the valve body at the first opening and opens the valve body at the second opening.   
     
     
         6 . The oil feed type compressor according to  claim 4 , wherein
 the controller controls the second period as a time longer than a time taken for the oil to be discharged, the oil having been stored in the reservoir during the first period.   
     
     
         7 . The oil feed type compressor according to  claim 2 , wherein
 the controller keeps the valve body at a first opening while an integrated value of a product of the load ratio and the operating time of the compressor body is less than a predetermined value, and keeps the valve body at a second opening larger than the first opening for a predetermined period when the integrated value of the product of the load ratio and the operating time of the compressor body has reached the predetermined value.   
     
     
         8 . The oil feed type compressor according to  claim 7 , wherein
 the controller closes the valve body at the first opening and opens the valve body at the second opening.   
     
     
         9 . The oil feed type compressor according to  claim 7 , wherein
 an amount of oil stored in the reservoir until the integrated value has reached the predetermined value is equal to or less than an allowable amount of oil that can be stored in the reservoir.   
     
     
         10 . The oil feed type compressor according to  claim 7 , wherein
 the predetermined period is longer than a time taken for the oil to be discharged, the oil being stored in the reservoir until the integrated value has reached the predetermined value.   
     
     
         11 . The oil feed type compressor according to  claim 3 , wherein
 the controller constricts the opening of the valve body when a reduction in the pressure detected by the pressure sensor while the valve body is being open has reached a predetermined value.   
     
     
         12 . The oil feed type compressor according to  claim 3 , wherein
 the controller opens the valve body after having closed the valve body for a predetermined period, and closes the valve body when a reduction in the pressure detected by the pressure sensor while the valve body is being open has reached a predetermined value.   
     
     
         13 . The oil feed type compressor according to  claim 12 , wherein
 the predetermined period varies according to a load ratio of the compressor body.   
     
     
         14 . The oil feed type compressor according to  claim 3 , wherein
 the controller issues notification about an abnormality when a period taken for a reduction in the pressure detected by the pressure sensor to reach a predetermined value from a time of opening of the valve body exceeds a predetermined period.   
     
     
         15 . The oil feed type compressor according to  claim 3 , wherein
 the controller records, while the valve body is being open, a count of events where a ratio of a reduction in the pressure detected by the pressure sensor to an elapsed time does not reach a predetermined value, and issues notification about an abnormality if the count has reached a predetermined count.   
     
     
         16 . The oil feed type compressor according to  claim 3 , wherein
 the pressure sensor is disposed near a region where the delivery pipe system is connected to the second oil separator.   
     
     
         17 . The oil feed type compressor according to  claim 1 , wherein
 the valve body includes a normally open ON-OFF solenoid valve.   
     
     
         18 . The oil feed type compressor according to  claim 1 , wherein
 the oil discharge passage has a downstream opening held in fluid communication with a low-pressure side of the compressor body, and discharges the oil that has been secondarily separated from the compressed gas by the second oil separator to the low-pressure side of the compressor body.   
     
     
         19 . The oil feed type compressor according to  claim 1 , wherein
 the second oil separator has a tubular case whose upper end is closed and whose lower end is open, a tubular filter positioned inside the case and having upper and lower ends open, and a delivery pipe extending upwardly from a lower portion of the filter, having an upper end opening positioned within the filter, and being held in fluid communication with the delivery pipe system.   
     
     
         20 . The oil feed type compressor according to  claim 1 , wherein
 the first oil separator includes a swirl-separation-type gas-liquid separator.