Abstract: A multi-mode fluid nozzle includes a generally-cylindrical mixing chamber with a stream mode fluid inlet connected to one side of the chamber, a fluid outlet connected to the opposite side of the chamber and a mist mode fluid inlet connected to the periphery of the chamber. The discharge pattern of the multi-mode fluid nozzle is dependent upon the inlets from which fluid enters the mixing chamber such that when the fluid enters the mixing chamber through the stream mode fluid inlet, the fluid exits the fluid outlet in a stream flow discharge pattern, when the fluid enters the mixing chamber through the mist mode fluid inlet, the fluid exits the fluid outlet in a mist flow discharge pattern and when the fluid enters the mixing chamber through the stream mode and the mist mode fluid inlet, the fluid exits the fluid outlet in a droplet flow discharge pattern.

Abstract: The water-saving nozzle has an outer housing that includes an outer vortex screw in operative engagement with an inner housing that is disposed inside the outer housing. The vortex screw has helical threads. The inner housing has an inner vortex screw with outside helical threads. When water passes through the outer and inner vortex screws the water is rotated before the water passes into the vortex chambers of the inner and outer housings. The water discharged from the outer housing forms an outer dome shape and the water discharged from the inner housing forms an inner dome shape inside the outer dome shape.

Abstract: The invention relates to a burner housing for a pellet grill having two or more elongated apertures configured to have a first end with an adjacent first width and a second end with an adjacent second width, the adjacent second width relatively greater than the adjacent second width. The burner housing generates an air vortex when in burner operation in such a manner as to provide relatively more air movement in an area somewhat distal to the burner, thereby retaining an optimal amount of ash during lengthy cooking cycles while also providing optimal fuel-to-air characteristics.

Abstract: A low pressure water mist nozzle for active fire protection from water supplied with supply water pressures of 0.5 bar to 20 bars, characterized by having a separation wall (3) with multiple openings (4) of sizes 01 mm to 02, 5 mm in angles of 10° to 50° to the wall surfaces, which are followed by a cavity (8) having a centrally located outlet opening (6) in its end wall, which are located opposite the separation wall (3) containing multiple openings (4).

Abstract: A shower head includes a body including a head unit and a tap water flow path. The head unit has one end connected with a hose through which water flows and an opening formed at the other end. A bottom plate is fixed inside the head unit and including a hole at a central part. A micro bubble generator is placed on the bottom plate and including a micro bubble generating path inside. A tornado plate is positioned between the bottom plate and the micro bubble generator and including an eccentric hole configured to achieve an increased flow speed by swirling the water. A pressing plate houses the micro bubble generator and is fixed inside the head unit together with the bottom plate. A tubular cap is fitted to the opening of the head unit and housing the micro bubble generator inside.

Abstract: A spray head for a power sprayer configured to generate a continuous sheet-like water shield around a center stream of water is disclosed. A water delivery device for use with a sink is disclosed, the water delivery device may produce a stream of water surrounded by a continuous shield of water.

Abstract: A spray nozzle includes a nozzle body, the body having an inner wall and an outer wall, a first opening, a second opening, wherein the diameter of the second opening is less than the diameter of the first opening, wherein the first and second openings have threaded portions, a spray opening, the spray opening at an end of the second opening, and an inner vane, wherein the inner vane includes threads corresponding to the threads of the second opening, a vane face, wherein the vane face faces toward the spray opening, a vane protrusion, the protrusion being perpendicular to the face, wherein the face and the protrusion are on opposite sides of the vane, wherein the vane protrusion faces away from the spray opening, at least one vane groove emanating outwardly from the center of the vane face.

Abstract: Provided is a descaling nozzle that can efficiently remove scale from a steel sheet. A discharge section at an end of a descaling nozzle includes a discharge hole (main flow orifice) and a branch hole (branch flow orifice) that are connected to a large diameter portion that forms a cylindrical channel. The branch flow orifice discharges a part of water flow in the large diameter portion so that cavitation occurs at a boundary between the part of water flow discharged from the branch flow orifice and water flow that is discharged from the discharge hole.

Abstract: An emergency eyewash unit includes a pair of water discharge ports oriented to produce a pair of upwardly directed, diverging water streams for inside-out flush flow of contaminants from a person's eyes. These eyewash streams can be combined with a plurality of smaller upwardly directed facewash streams for flushing contaminants from a person's face. The eyewash and/or facewash streams are produced by an eyewash body adapted for rotatable mounting onto a water supply conduit, with a locking clip normally preventing undesired rotational disassembly. The eyewash body may be used in combination with an overhead emergency shower which, in one preferred form, includes a shower spray head carrying multiple flow control and flow shaper elements to produce a substantially uniformly dispersed shower spray pattern.

Abstract: Methods, processes, and apparatuses for the large scale synthesis of carbon nanostructures are provided. The apparatus for continuous large scale production of SWNTs includes a chamber. Positioned in one end of the chamber is a piston and at the other end is a tangential vortex created by gases forced into the chamber from opposite sides of the chamber walls. The chamber can be heated to reduce or eliminate agglomeration of small particles. The piston is used to push the catalyst towards the vortex, and the injection rate is controlled by the speed of the piston and the gas flow rate to create the vortex that also act as the transport gas. Thus, greater than 1 kg/h of an aerosolized, deagglomerated dry powder catalyst can be delivered to the reactor at a constant flow rate.

Abstract: A fuel injector has an injector body and a control rod, which is movable in the injector body along an axis for controlling opening/closing of a nozzle that injects fuel in an engine cylinder; the injector body houses a metering servovalve, provided with a control chamber and with an open/close element of a balanced type, axial sliding of which causes a variation in pressure in the control chamber; the metering servovalve comprises a valve body made of two pieces coaxially coupled to one another via a deformable ring, which defines also a gasket for guaranteeing fluid tightness between the two pieces and maintains in a fixed position a disk on which a calibrated restriction is made.

Abstract: An atomizer includes an atomizer body having a liquid inlet and a spray outlet with a liquid flow circuit defined through the inner atomizer body for fluid communication of liquid from the inlet to the spray outlet. The liquid flow circuit branches into a plurality of sub-circuits. Each sub-circuit is configured to produce a spray cone of atomized liquid issuing from the spray outlet such that the spray cone of each sub-circuit has a different cone angle. The sub-circuits are mechanically separated from one another to limit interaction of liquid in the sub-circuits and thereby produce a distinct and stable spray cone from each sub-circuit over a range of liquid flow rates.

Abstract: An apparatus for controlling a flow of fluid in an emergency fixture includes a body; and a control element at least partially located in the body and configured to impart rotation into the fluid flow. The control element includes a first substantially cylindrical member defining a first outlet portion, the first outlet portion configured to guide a first portion of the fluid flow out of the control element as an axial flow; a second substantially cylindrical member coupled to the first member; and a plurality of radially extending members extending between the first member and the second member, each of the plurality of members comprising a deflection surface angled relative to a second portion of flow and configured to cause rotation of the second portion of flow.

Abstract: An integral miniaturized nebulizer for an elastically deformable bottle (1), provided with a rotatable closing cap (5), with discharge orifice, and with a suction tube (16) immersed in the liquid to be nebulized, includes a head (3) in a single piece with a body (4) connectable to an elastically deformable bottle (1). The head (3) internally has an elbow conduit (13) for the liquid to be sprayed, extending in a longitudinal segment (14) able to engage the suction tube (16), and in a transverse segment (15) able to end in the discharge orifice of the rotatable closing cap (5) when the cap (5) is in the nebulization position. The transverse segment (15) is coaxial inside a conduit (18) of the air inside the bottle (1) and in communication therewith via a plurality of radial channels (25) drilled in the terminal end of the same transverse segment (15).

Abstract: Spray nozzle comprising a front wall, an outlet channel delimited by a lateral surface substantially of revolution about an axis perpendicular to the front wall, an intake conduit supplying fluid product to the outlet channel, said intake conduit extending in a plane perpendicular to the axis, substantially tangentially to the lateral surface of the outlet channel, between an upstream and a downstream end opening out into the lateral surface of the outlet channel, the lateral surface of the outlet channel comprising a relief arranged radially relative to the axis and suitable for forming a static surface layer of fluid product.

Abstract: A method of manufacturing gas and/or fuel swirlers for fuel injectors and combustor domes and cone-shaped swirlers so manufactured are disclosed. The disclosed conical swirlers feature cut-through slots on a cone-shaped body. The contour and spacing of the slots are configured and arranged to accommodate a wide range of requirements for fluid flow areas and swirl strengths. Preferably, the cone-shaped swirlers can be manufactured by wire EDM processing. More preferably, multiple cone-shaped swirlers can be manufactured simultaneously by nesting swirler blanks in a stack and wire EDM processing the stack as a unit. The cone-shaped pinwheel swirler fits well into various fuel injector heads, enabling the injectors to reduce the frontal surface area and flat area for minimal potential of carbon formation.

Abstract: A liquid atomizer for agricultural use includes at least one canal in fluid communication via a chamber with an outlet. At least a section of the canal extends along a straight line and tangentially opens into the chamber.

Abstract: A multi-point injector includes an annular body defining an interior annular flow passage. The annular body includes a fluid inlet and a plurality of circumferentially spaced apart fluid outlets in fluid communication with the interior flow passage. Each of the outlets has a swirl chamber formed within the annular body associated therewith for imparting swirl to fluid delivered thereto.

Abstract: The design of the spray nozzle in an aerosol dispenser controls the characteristics of the spray that is produced. In a nozzle that comprises the elements of a multiplicity of inlet channels leading to a swirl chamber and an outlet orifice, the perception of wetness of a spray, such as an aqueous alcoholic deodorant spray, can be reduced by dimensioning the respective elements so that the sum of the widths of the inlet channels is less than the diameter of the swirl chamber and at least 1.5 times the diameter of the outlet orifice and the outlet orifice has a diameter of at least 0.3 mm together with the inlet channels being short, such as less than 0.5 mm. The new nozzle is especially suitable for spraying compositions having a low volatile organic carbon content and compositions comprising a significant proportion of water.

Abstract: An apparatus for controlling a flow of fluid in an emergency fixture is disclosed. The apparatus includes a body and a control element at least partially located in the body and configured to impart rotation into the fluid flow. The control element includes an inlet that receives the fluid flow. The control element also includes a first outlet portion configured to guide a first portion of the fluid flow out of the control element as an axial flow and a second outlet portion configured to provide rotation to a second portion of the fluid flow relative to the axial flow. The first portion of the fluid flow exits the control element at a position downstream from the position that the second portion of the fluid flow exits the control element.

Abstract: Disclosed is a method and device for fluid handling relating to controlling and directing the water streams from spray devices utilizing multiple liquid streams to produce an effluent that enhances a user's perception of spray performance. In the disclosed embodiments, a cavity acts as a mixing chamber for multiple fluid jets that enter the cavity at various locations, angles and flow rates. By positioning these inlet ports in the upper portion of the cavity, and with the ability to precisely direct and meter the fluid flow, the spray device may achieve a multitude of flow patterns from an outlet.

Abstract: Provided is a manual air-actuated spray paint apparatus and associated method for evenly disbursing paint in a controlled manner. Such an apparatus preferably includes a portable reservoir for holding the paint therein and a hand-actuated paint applicator removably coupled thereto. A mechanism for simultaneously discharging a single stream of paint and a volume of air may also be included. A discharge spout is removably mated to and in fluid communication with the paint applicator for mixing the single paint stream and the volume of air as they pass through the spout. A trigger is pivotally mated to the housing and is articulated between tensioned and released positions to activate the paint discharging mechanism. When the trigger is engaged, the paint is directed upwardly out of the reservoir and travels out the discharge spout to be applied to the surface intended to receive the paint.

Abstract: A spray nozzle assembly for directing thin, straight line, high pressure liquid spray onto moving steel slabs for penetrating and removing scale buildup in steel processing operations. The spray nozzle assembly includes a high impact attachment tube for accelerating liquid flow, a tungsten carbide spray tip at a discharge end of the high impact attachment tube for directing a flat spray pattern, an inlet defined by a strainer at an upstream end of the high impact attachment tube, and a staged vane section intermediate the inlet and spray tip for reducing liquid turbulence in the flow passageway. The vane section comprises a pair of axially spaced vanes each having a plurality of radial vane elements that define a plurality of laminar flow passageways, with the laminar flow passageways of one vane being circumferentially offset to the laminar flow passageways of the other vane.

Abstract: A dome pump spray assembly employing a known structure of a liquid dome pump in association with a uniquely configured spray spout to achieve atomization of liquids such as soaps, sanitizers, disinfectants and the like. The spray spout includes a deflector which is in juxtaposition to a spout spray tip having angled partial depth passages therein that extend to a central tapered outlet orifice, the passages and orifices generating a vortex of cyclonic action that serves to achieve atomization of the liquid as it passes therethrough.

Abstract: A spray head for a power sprayer configured to generate a continuous sheet-like water shield around a center stream of water is disclosed. A water delivery device for use with a sink is disclosed, the water delivery device may produce a stream of water surrounded by a continuous shield of water.

Abstract: A full cone liquid spray nozzle is provided. The spray nozzle includes a nozzle body having a discharge orifice at a downstream end and an inlet at an upstream end for connection to a liquid supply. A liquid flow passageway extends through the nozzle body communicating between the inlet and the discharge orifice. A vane is disposed in the liquid flow passageway upstream of the discharge orifice. The vane has a plurality of V-shaped passageways therein. Each V-shaped passageway extends inward at an angle with respect to a longitudinal axis of the vane between an upstream face and downstream face of the vane. A whirl and mixing chamber defined by the liquid flow passageway is arranged between the vane and the discharge orifice.

Abstract: An apparatus for regulating fluid flow through a spray nozzle comprising a circular chamber (1) defined by spaced apart end walls, a peripheral side wall (3), a central axis, and a first inlet at or near the peripheral side wall (3) to allow a flow of fluid to enter said chamber (1) tangential to the peripheral side wall (3), and an outlet (4) exiting through one of the end walls. In use a flow of fluid entering through the first inlet has a primary lower layer (16) that follows a first circular flow path which forms a vortex commencing at the peripheral side wall (3) and increases in velocity and pressure towards the outlet and at least one secondary upper layer (17) that substantially follows a second flow path radially inwardly towards the central axis. The primary lower layer (16) and the secondary upper layer (17) interact and support each other over at least a portion of flow between the inlet and outlet (4).

Abstract: The heating injector in which the fuel is heated within a short time when starting and the size of a fuel atomized particle is very small h as casing 10 for a fuel injection valve which supplies fuel to an engine, orifice member 50 with an orifice through which fuel passes, plunger 20 which carries out switching action of orifice, swirl chip 30 which contacts the orifice member and the casing at a plurality of positions, and forms a fuel passage blocked by a plurality of narrow portions and a fuel heating space channel where entrance side was blocked by the narrow portion in the downstream side, and a heater which is arranged between fuel passage forming member and casing and supported by either of the fuel passage forming member or the casing in a plurality of parts in the fuel passage.

Abstract: An actuated atomizer is adapted for spray cooling or other applications wherein a well-developed, homogeneous and generally conical spray mist is required. The actuated atomizer includes an outer shell formed by an inner ring; an outer ring; an actuator insert and a cap. A nozzle framework is positioned within the actuator insert. A base of the nozzle framework defines swirl inlets, a swirl chamber and a swirl chamber. A nozzle insert defines a center inlet and feed ports. A spool is positioned within the coil housing, and carries the coil windings having a number of turns calculated to result in a magnetic field of sufficient strength to overcome the bias of the spring. A plunger moves in response to the magnetic field of the windings. A stop prevents the pintle from being withdrawn excessively. A pintle, positioned by the plunger, moves between first and second positions.

Abstract: In many applications where it is desired to distribute a liquid onto a surface at a very small angle of incidence, it will be necessary to reduce the momentum of the droplets to prevent ricochet off the surface. Obvious methods such as using a restrictor, reducing the operating pressure, etc. are not satisfactory due to the inadequate flow, susceptibility to clogging, etc.

Abstract: A spray nozzle (11) includes a body (12) defining an axial cavity and having, housed in the cavity, from upstream to downstream in the liquid direction of flow X-X?, a calibrating nozzle tip (33), a piece called divergent (19) and a piece called convergent (16). More particularly, the calibrating nozzle tip (33) and the convergent (16) are respectively integral with a plug (21) and the nozzle body (12), the plug being hermetically threaded into the cavity of the nozzle body (12) and including at least one gripping zone (22), while the divergent (19) is an independent piece immobilized in the cavity of the nozzle body (12).

Abstract: A device for packaging and dispensing of a cosmetic product which includes a container to hold the product, with the container being delineated by a body. A movable element moves relative to the container body and is capable, in response to an action exerted manually on a surface of an actuating element, of moving from a first position to a second position. The movable element incorporates a first lip intended to engage with an inner wall of the body, during at least part of its movement, thereby isolating a dose of product inside the container in a manner to cause its expulsion through at least one dispensing aperture. The movable element also includes an upper lip capable of being applied in a leaktight manner against the inner wall during at least part of its movement from the first position to the second.

Abstract: An assembly for packaging and dispensing a product, especially a cosmetic product. The assembly includes a container containing the product and delimited by a body, one end of which is closed by a bottom. A movable component is movable relative to the body of the container and is capable, in response to an action exerted manually on a surface of an actuation component, of passing from a first position in which the volume delimited between the movable component and the bottom of the container is a maximum, to a second position in which the volume is a minimum, so as to pressurize the product contained in the volume and deliver the product through at least one dispensing orifice. When the movable component returns from the second position towards the first, air passes into the volume through at least one passage formed between the movable component and an internal surface of the container.

Abstract: An atomizing nozzle (20) for use in a misting system and a process (200) for manufacturing the atomizing nozzle (20) are provided. The atomizing nozzle (20) is made up of a nozzle body (24), a metallic orifice insert (26), and a non-metallic impeller. The nozzle body (24) has an inlet end (30), has an outlet end (32), has an insert recess (36) proximate the outlet end (32), and encompasses a first chamber (42). The metallic orifice insert (26) is affixed to the nozzle body (24) within the insert recess (36) and encompasses a second chamber (66). The non-metallic impeller (28) is configured to reside within the first and second chambers (42,66) between the metallic orifice insert (26) and the nozzle inlet end (30).

Abstract: The invention relates to a method and a device for distributing liquid media, in particular extinguishing fluids. The aim of the invention is to provide a method and a device of the aforementioned type which can be used to produce a fine mist of small droplets and a jet spray of large droplets at separate moments, at approximately the same operating pressure of the extinguishing fluid, depending on the outbreak and the development of the fire, whilst at the same time minimising water consumption, reducing water damage caused during a fire and increasing cost-effectiveness, by creating a modular system which can be universally installed. To achieve this, the intensity of the vortex and the proportion of fine or large droplets in the spray cone is adjusted by regulating the quantity and speed of the flow during the distribution of the extinguishing fluid in at least two sub-streams and by combining said sub-streams with at least one additional sub-stream.

Abstract: The present invention pertains to a trigger sprayer which is connectable to two container volumes containing separate liquids. The sprayer has a trigger that is manipulated to draw the separate liquids into two separate pump chambers and then supply the two separate liquids from the pump chambers to a discharge passage of the sprayer. In the discharge passage the two separate liquids are mixed together prior to their being dispensed from the discharge passage as a spray.

Abstract: A spray nozzle particularly useful for directing a liquid coolant onto continuously cast metal shapes. The spray nozzle includes a nozzle body having a liquid flow passageway communicating with a discharge orifice and a vane disposed within the passageway upstream of the discharge orifice. The vane has a central orifice for creating an axial flow stream and a plurality of circumferentially spaced angled passages for tangentially directing a plurality of liquid flow streams which create liquid turbulence, breakdown and intermixing with the axial flow stream such that liquid emitted from the discharge orifice is adapted for more uniform cooling of a cast metal notwithstanding changes in liquid pressure commensurate with changes in the rate at which the metal is cast.

Abstract: A spray nozzle particularly useful for directing a liquid coolant onto continuously cast metal shapes. The spray nozzle includes a nozzle body having a liquid flow passageway communicating with a discharge orifice and a vane disposed within the passageway upstream of the discharge orifice. The vane has a central orifice for creating an axial flow stream and a plurality of circumferentially spaced angled passages for tangentially directing a plurality of liquid flow streams which create liquid turbulence, breakdown and intermixing with the axial flow stream such that liquid emitted from the discharge orifice is adapted for more uniform cooling of a cast metal notwithstanding changes in liquid pressure commensurate with changes in the rate at which the metal is cast.

Abstract: The present invention pertains to a trigger sprayer which is connectable to two container volumes containing separate liquids. The sprayer has a trigger that is manipulated to draw the separate liquids into two separate pump chambers and then supply the two separate liquids from the pump chambers to a discharge passage of the sprayer. In the discharge passage the two separate liquids are mixed together prior to their being dispensed from the discharge passage as a spray.

Abstract: A foam dispenser utilizes a deformable reservoir, a foamable fluid and air or other gas; a discharge device and an arrangement for producing foam that includes a plurality of mesh screens. When the dispenser is operated, air from inside the dispenser is mixed with the fluid to produce foam. The dispenser employs a shaped and resilient deformable seal for use in quickly recharging the container with air used in the creation of foam. The dispenser also advantageously employs an integrally molded swirl manifold to create a foam of excellent quality and consistency.

Abstract: The invention relates to an atomizing burner, especially for use in an automobile auxiliary heating system, comprising an atomizing nozzle (2) for processing the fuel, an ignition device (29) and a combustion chamber (8). An iar conduction device (10, 12, 14) is connected upstream of a nozzle holder (3) of the atomizing nozzle (2) in order to achieve finer atomization of the fuel. Said air conduction device subjects the combustion air streaming into the atomizing nozzle (2) to a swirl.

Abstract: A swirling effect nozzle has substance feed channels opening out into a swirling chamber which communicates with an outlet orifice. The ratio Ap/Ao where Ap is the smallest total section offered by the channels to the passage of the substance and Ao is the section of the outlet orifice is less than or equal to 0.5.

Abstract: The present invention provides a nozzle assembly for producing varying water patterns. In one embodiment, a variable first flow of water is constrained to flow in a linear direction. A variable second flow of water is applied to the first flow of water to impart a twist to the first flow of water. The resulting flow of water has a height component that is largely determined by the first flow of water and a lateral component that is largely determined by the second flow of water. For example, if there is only a first flow and no second flow, the resulting water effect is a narrow column of water. If there is no first flow and a second flow, the resulting water effect is a cone with a small vertical dimension. If there are both first and second flows, a cone is produced with a vertical dimension that is largely determined by the first flow and a lateral dimension that is largely determined by the second flow.

Abstract: A burner for liquid and/or gaseous fuels (A, B, C) for a premixing combustion system in graduated load operation of a combustion chamber includes at least one inner partial body (2) that extends in the flow direction; at least one outer partial body (4) which extends conically opposite to the inner partial body (2); and at least one other surrounding pipe (8). The inner and outer partial bodies form a central flow structure, whereby the two are supplied with the flow in effective connection with each other with combustion air (13, 14, 15). The main part of this combustion air (13) then flows through the two partial bodies through air inlet slits (11, 12) and forms one rotational flow in each of the adjoining flow chamber (5, 7).

Abstract: A low NO.sub.x fuel nozzle assembly 10 includes a nozzle 24 with a tangential entry (TE) swirler 46 and centerbody element 48 each releasably mounted to an assembly support structure 26, such as to readily provide for operator access to the nozzle's major elements for the purpose of repair or replacement.

Abstract: A fire extinguishing head includes a pair of medium range nozzles having a shooting distance shorter than that of a long range nozzle and disposed on opposite sides of the long range nozzle in such a manner as to sandwich the long range nozzle. A short range nozzle having a shooting distance shorter than that of the medium range nozzle is disposed below the long range nozzle.

Abstract: A sprayer has a spray pattern which can be varied by the provision of a second fluid flow path which partially negates the spin velocity to produce a spray having a narrow spray cone producing spray. An opening in the spinner probe establishes the second fluid flow path from the discharge passage, and can be selectively opened and closed upon plunger rotation relative to a hollow piston stem.

Abstract: A trigger actuated fluid dispenser for simultaneously dispensing disparate fluids separately stored in separate fluid compartments of a container includes side-by-side pump cylinders receiving side-by-side pump pistons reciprocable simultaneously during each pressure stroke applied by a single trigger lever for separately and simultaneously pumping the disparate fluids along separate discharge paths.

Abstract: An air blast fuel nozzle includes a unitary structure which introduces not only axially swirling primary airflow into the primary zone of the combustor chamber, but also introduces radial inflow, coswirling, primary airflow into the premixing chamber immediately upstream of the primary zone of the combustor.

Abstract: Apparatus (10) for the automatic staining of tissue includes a body (12) on which a carousel (16) rotates. The carousel (16) is able to carry a number of slides (24) bearing tissue samples. A delivery head assembly (18) is mounted on the body (12) for movement across the diameter of the carousel (16). The head assembly contains a clear nozzle (20) and a spray nozzle (22). A version (50) of the spray nozzle (22) for spraying a fluid biochemical agent onto a slide (24) has a main body (52) a plug (56) in the main body (52) and a cap (54) on the main body (52) between which there is a swirl chamber (68) into which fluid passes from the body (52). The fluid enters the swirl chamber (68) such that flow in the chamber (68) is concentric to the chamber axis and thereafter flows from the body (52) through an exit ( 66), thus minimising damage to the biochemical agent.