Abstract: Provided are: a biological reaction device that reduces stress and damage visited on microorganisms, etc., in a biological reaction, and enables a biological reaction in which microorganisms, etc., are used to be efficiently and economically performed; and a biological reaction method in which the biological reaction device is used. In order to reduce the stress and damage visited on microorganisms, etc., the amount per minute of a biological culture solution that is extracted from a culture tank and then returned to the culture tank after being admixed with micro-nano-bubbles is set as at least 1% to less than 48% of the biological culture solution accommodated in the culture tank, and the reduction in the dissolved oxygen concentration associated therewith is compensated for by setting the oxygen partial pressure of a gas phase in the upper part of the biological culture solution in the culture tank as at least 0.23 atm to less than 0.

Abstract: The present invention is one for providing an apparatus and a method which make it possible to remove a foreign object or matter such as scale attached on an inner surface of a pipe easily for a short period of time by means of simple equipment and manner, and constituted as follows. Specifically, a holder (11) is attached onto an end of a pipe (P), an abrasion assisting member (16) fixed to a tip end of a support arm (15) is inserted into the pipe (P) by use of the holder (11) and stopped at an area (A) where oxide scale (S) is generated in a large amount. Then abrasive is sent with pressure into the pipe (P) by a blast device (14), and thus a flow rate of the abrasive in the scale-abraded area (A) is increased to abrade and remove the oxide scale (S) securely. Moreover, if required, a spiral groove (17) is formed on an outer circumference of the abrasion assisting member (16) to increase centrifugal force of the abrasive.

Abstract: The present invention is one for providing an apparatus and a method which make it possible to remove a foreign object or matter such as scale attached on an inner surface of a pipe easily for a short period of time by means of simple equipment and manner, and constituted as follows. Specifically, a holder (11) is attached onto an end of a pipe (P), an abrasion assisting member (16) fixed to a tip end of a support arm (15) is inserted into the pipe (P) by use of the holder (11) and stopped at an area (A) where oxide scale (S) is generated in a large amount. Then abrasive is sent with pressure into the pipe (P) by a blast device (14), and thus a flow rate of the abrasive in the scale-abraded area (A) is increased to abrade and remove the oxide scale (S) securely. Moreover, if required, a spiral groove (17) is formed on an outer circumference of the abrasion assisting member (16) to increase centrifugal force of the abrasive.