A device and a method for the surface treatment of a material by a pressurized jet of liquid nitrogen, supercritical cryogenic nitrogen or hypercritical cryogenic nitrogen that may be loaded with particles, use a device that includes a mixing chamber (10) closed by a downstream wall with an outlet orifice, and a diffusion focusing barrel (20) having an inlet and an outlet, the inlet being designed to be fastened to the mixing chamber (10) while being in fluid contact with the outlet orifice of the mixing chamber (10), the pressurized jet of nitrogen having to pass through the focusing barrel from the inlet to the outlet. The diffusion focusing barrel (20) includes a hollow tube having three successive portions placed one after the other, namely a convergent portion (21) located on the side of the inlet opening of the diffusion focusing barrel and whose inner face, considered in the direction of flow of the nitrogen jet, is convergent, a neck (22) whose inner face is cylindrical, and a divergent portion (23) ending in the outlet of the diffusion focusing barrel and whose inner face, considered in the direction of flow of the nitrogen jet, is divergent.

A method of comminuting the size of particles of frangible blast media from each particle's respective initial size to a size smaller than a desired maximum size includes directing a flow of entrained particles toward a gap, at a first location splitting the flow into at least a first and second flow, the particles are entrained in the first flow, the first flow travels through the gap and substantially no particles are entrained in the second flow, and rejoining the second flow with the first flow at a second location downstream of and proximal to the gap.

Methods of cleaning flow path components of power systems, and sump purge kits used in the same or related methods are disclosed. A method of cleaning may include removing a casing of the turbine system to expose a rotor of the turbine system, a plurality of flow path components coupled to the rotor and/or the casing, and a sump system in communication with the rotor. The method may also include pressurizing the sump system in communication with the rotor, and sealing a plurality of openings formed in the rotor. Additionally, the method may include exposing the rotor and the plurality of flow path components to steam to dry hydrocarbons formed on a surface of the rotor and a surface of the plurality of flow path components, and blasting the rotor and the plurality of flow path components with solid carbon dioxide (CO.sub.2) to dislodge the dried hydrocarbons.

A system for cutting an underwater structure, the system comprising: a cutting head, said cutting head comprising: an abrasive water jetting nozzle; a cryogenic nozzle; said abrasive water jetting nozzle and cryogenic nozzle mounted in fixed spaced relation; said cutting head arranged to position tips of the nozzles proximate to a cutting surface, and arranged to form a cutting zone defined by the nozzle tips and cutting surface; wherein a water repelling shield is located about said cutting zone and arranged to hinder water entering said cutting zone.

A device for producing dry ice pellets comprises a pressing cylinder, into which an inlet opening for feeding liquid carbon dioxide leads and which is equipped with a die, which has one or more openings, and with a piston, which is longitudinally movable in the pressing cylinder. Liquid carbon dioxide is fed to the pressing cylinder, is expanded at the inlet opening, is at least partially converted into carbon dioxide snow and is pressed against and through the die by the movement of the piston. The die is in the form of a cylindrical body that can be connected to the pressing cylinder and is equipped with feed-throughs, which are oriented parallel to a longitudinal axis of the die and are dimensioned in such a way that the length and the diameters of the feed-throughs correspond to the length and the diameters of the dry ice pellets to be produced.

An actuator is configured to couple with a controlled member and includes first and second pistons disposed in respective internal chambers. The first piston may be moveable between first and second positions. The second piston may be moveable between third and fourth positions. The second piston may be configured not to engage the first piston when the second piston is disposed at the third position. The second piston may be configured to move the first piston to the second position as the second piston moves from the third position to the fourth position. A resilient member may be disposed to resiliently urge the second piston toward the fourth position.

Systems and methods for cleaning and preparing a surface are described. The system includes a housing with a first hopper configured to receive a first material and a second hopper configured to receive a second material. A tube housing an auger may be located where the two hoppers meet. In this way, the materials are mixed in the tube before being pushed through a hose to a nozzle. The mixture can be sprayed out of the nozzle. The mixture only requires a single air source, and the system operates using a combination of gravity, venturi suction, vibration, an auger and the like.

A blasting medium includes first ice particles and second particles having a hardness between 2000 and 2500 HV. The second particles are embedded in the surface and in the volume of the first particles.

A comminutor reduces the size of particles of frangible blast media from each particle's respective initial size to a size smaller than a desired maximum size. The frangible blast media may be entrained in a flow of transport gas. The comminutor includes an inlet and an outlet, both in fluid communication with an internal flow passageway. The internal flow passageway includes a first intermediate passageway which comprise the gap defined by two rotating rollers and a second intermediate passageway which includes an inlet disposed proximal the gap, extending in an upstream direction therefrom.

The present invention is to provide an antibacterial molded article that can increase options for the material and shape of the molded article, and a method for manufacturing the same. The object is achieved by an antibacterial molded article containing a plastic molded article, the plastic molded article having a rough region having an arithmetic average roughness Ra of a roughness curve in accordance with JIS B 0601 (2013) of 0.14 μm or greater and 0.72 μm or less provided on a surface with which bacteria can come into contact.