Abstract: A water distribution system facilitates automatic corrosion control. The operator enters a set of values of parameters associated with water in the system. The system automatically and repeatedly measures the temperature and pH of the water. The system then computes a target pH for the water, according to a function which depends on the temperature and the other parameters, and on an index of corrosion. The system then varies the pH of the water, so as to minimize the deviation between the measured pH and the target pH. The system performs this process repeatedly, to maintain the desired properties of the water. In particular, the operator can easily and automatically control the water so as to make it either more corrosive or more scale-forming, in such a manner as to minimize the dissolution of lead or copper into the water while limiting the tendency of the water to form scale.

Abstract: The present invention produces discrete droplets of cryogenic liquid, suitable for injection into receptacles such as cans or plastic bottles, at high speeds. A container of cryogenic liquid includes a hole and an orifice, spaced apart from each other, and defining a path for liquid to flow out of the container. A conduit directs a gas into the space between the hole and the orifice. The orifice is formed in an orifice plug which can be adjusted so as to vary the volume of the space between the hole and the orifice. When gas fills the space, the gas tends to prevent the outflow of liquid. When gas is withdrawn from the space, liquid can flow out of the container. By rapidly closing opening a valve which supplies gas to the space, and by proper choice the volume of the space, the liquid can be made to fall out of the container in discrete droplets.