Abstract: A method of cleaning an ultrafiltration membrane module includes installing an ultrafiltration membrane in an ultrafiltration membrane module, supplying deionized water to the ultrafiltration membrane module, and flushing the ultrafiltration membrane module with the deionized water by increasing decreasing a flow rate of the deionized water supplied to the ultrafiltration membrane module.

Abstract: An ultrapure water supply apparatus includes a first filtering device, a second filtering device, a first tank between the first and second filtering devices, a third filtering device, a second tank between the second and third filtering devices, a fourth filtering device, a third tank between the third and fourth filtering devices, and a gas supply device connected to each of the first to third tanks and configured to supply an inert gas. Each of the first to third tanks includes a tank body and a breather valve coupled to the tank body and connected to a storage space in the tank body. Each of the first to fourth filtering devices includes at least one selected from an activated carbon filter device, an ion exchange resin device, a reverse osmosis membrane device, and a hollow fiber membrane device.

Abstract: A fluid supply includes a first fluid source configured to supply a first fluid, a second fluid source configured to supply a second fluid, a heat exchanger configured to exchange heat between the first fluid and the second fluid, a first fluid recovery tank configured to recover the first fluid that has passed through the heat exchanger, and a first transfer pipe configured to transfer the first fluid from the first fluid source to the first fluid recovery tank via the heat exchanger. The heat exchanger may be disposed at a vertical level higher than a vertical level of the first fluid recovery tank.

Abstract: An ultrapure water manufacturing facility includes: a first tank; a plurality of reverse osmosis membranes sequentially arranged downstream of the first tank; an electrodeionization device arranged downstream of the plurality of reverse osmosis membranes; an ion exchange resin tower arranged downstream of the electrodeionization device and filled with a boron selective resin; and a chemical supplier arranged between the plurality of reverse osmosis membranes and configured to supply a pH regulator to treatment-target water.