Abstract: An autonomous apparatus for cooking food includes a support body, an openable lid, an internal container which can be extracted/inserted with respect to said support body and open at the top, at least a heating device, and one or more elements to generate a flow of air toward the inside of said container. The air flow generator element is connected to a return exit with a suction mouth made in correspondence with an internal wall of said support body and cooperating with a plurality of through holes made on at least one portion of the lateral wall of the internal container.

Abstract: Methods, systems, and devices to enhance fracturing fluid delivery to subsurface formations to enhance hydrocarbon production from the subsurface formations may include providing a manifold coupling having a manifold coupling passage with a manifold coupling axis. The manifold coupling may include a first inlet passage positioned to provide fluid flow between a first fracturing fluid output and the manifold coupling passage, and a second inlet passage positioned opposite the first inlet passage to provide fluid flow between a second fracturing fluid output and the manifold coupling passage. The first inlet passage may have a first inlet passage cross-section at least partially defining a first inlet axis extending transverse relative to the manifold coupling axis. The second inlet passage may have a second inlet passage cross-section at least partially defining a second inlet axis extending transverse relative to the manifold coupling axis and not being co-linear with the first inlet axis.

Abstract: Methods and apparatus for controlling a characteristic of a cement slurry at a cementing unit, including regulating a characteristic of the cement slurry employing a closed loop feedback arrangement in the cementing unit, and adjusting a gain of the closed loop feedback arrangement in response to sampling an error of the characteristic.

Abstract: An infeed chute for a material application machine includes a riser and a water spreading unit. The riser includes a sidewall and defines an infeed opening extending through the riser. The riser is configured to be coupled to an opening of a tank of a material application machine such that application material passed through the infeed opening of the riser enters the tank of the material application machine. The sidewall includes a water inlet formed therein. The water spreading unit is coupled to the water inlet and is configured to direct water laterally across the infeed chute.

Abstract: A mixing apparatus for preparing mortar has a screw conveyor for conveying dry material, such as a mixture of sand and cement, from a storage vessel to a mixing chamber. The mixing chamber has an inlet end, adapted to receive dry material from an outlet end of the screw conveyor, an outlet end for dispensing wet mortar, and a water feed between the inlet and outlet ends for delivering a metered flow or quantity of water into the mixing chamber. A mixing device within the mixing chamber mixes the dry material and water and controls passage of material from the inlet to the outlet end. The outlet end is located above said inlet end so the dry material falls under gravity from the outlet end into the mixing chamber, maintaining separation between the dry material in the screw conveyor and the wet material in the mixing chamber.

Abstract: A discharge gate is provided for delivering a mixed slurry from a gypsum slurry mixer, and includes a first extractor port configured for generating a first density slurry for a first gypsum layer, and a second extractor port configured for generating a second density slurry for a second gypsum layer. A channel is defined by a front panel and a side panel of the discharge gate for delivering the first and second density slurries from the slurry mixer. The first extractor port extends semi-tangentially from the front panel of the discharge gate, and is connected in fluid communication with the front panel via the channel and a first slurry passageway disposed within the first extractor port for delivering the first density slurry.

Abstract: A discharge gate for a gypsum slurry mixer is provided, and includes a gate adapter having an inlet opening configured for receiving the slurry, and an outlet opening configured for delivering the slurry to a dispensing device. The gate adapter has two different transitioning cross-sectional geometries at opposite ends. Specifically, the gate adapter includes an inlet section having a quadrilateral inlet opening; an outlet section having a substantially circular outlet opening; and a transition section sandwiched between the inlet and outlet sections.

Abstract: A device for depositing a mixture of powders to form an object with composition gradients, including: a plurality of tanks respectively configured to contain different powders; a powder mixer placed under the tanks and including a rotatably mounted mixing member; a plurality of powder dispensing mechanisms respectively cooperating with the tanks, and each configured to regulate mass flow rate of the powder escaping from a respective of the tanks towards the mixer; a powder mixture collector placed under the mixer; and a powder mixture dispenser placed under the collector.

Abstract: A mixing device having a mixing container and has a single-shaft agitator that extends into the mixing container. At the end of the drive shaft, a rotor body is arranged slightly above the bottom of the mixing container. The rotor body comprises a plurality of mixing blades, wherein the blades are, in one example, star-shaped and fixed in position to each other. A first end of the drive shaft is coupled to a motor and a second end of the drive shaft is configured to extend into the mixing vessel, wherein the blades are attached onto the second end of the drive shaft. The blades in one example include at least two coincidental knife-edged blades such that at least one of the knife-edged blades is facing upward. The mixing device in one example is used to mix calcium aluminate-containing slurries.

Abstract: An apparatus includes an elongate shaft, a first paddle including a connecting member disposed generally parallel to the shaft and a cross member disposed generally perpendicular to the shaft and coupled thereto, wherein the connecting member includes at least one notch formed along an edge thereof, and a second paddle including a connecting member disposed generally parallel to the shaft and a cross member disposed generally perpendicular to the shaft and coupled thereto, wherein the connecting member includes at least one notch formed along an edge thereof.

Abstract: There is described a machine for homogenizing a bitumen-based mixture with polymer granules. The machine includes an outer container and a cylindrical sleeve, which is housed within the outer container and is provided with a perforated side wall, on which a plurality of through apertures is obtained, each of the holes comprising a sharp cutting edge. The machine further includes a homogenizer assembly, which is mounted so as to axially rotate within the sleeve in order to rotate about a vertical axis, and is configured so as to displace, during its rotation, at least part of the bitumen-based mixture and the polymer granules along a direction which is substantially tangential to the inner surface of the perforated side wall of the sleeve so as to induce the polymer granules to impact against the sharp cutting edge of the through apertures.

Abstract: A chemical analyzer supplies a sample and a reagent into a reaction container provided with an opening mixes a fluid which is to be measured and contains the sample and reagent supplied into the reaction container, measures a property of the fluid in the reaction container, and controls the drive for the mixer. The mixer has a vertical drive machine to move the mixing tool up and down. The control unit controls the vertical drive machine to move the mixing tool up and down in the fluid to be measured in the reaction container so as to cause upward and downward flow of the fluid which is to be measured and is positioned below the mixing tool.

Abstract: The application relates to a metering apparatus for introducing a powdery medium into a fluid, comprising a guide device for guiding the fluid and a metering device, said metering device being arranged above the guide device such that the powdery medium released by the metering unit is scattered onto the surface of the fluid.

Abstract: A centrifugal concrete mixer includes a base frame, a mixing drum provided on the base frame, a transmission means and two stirring pieces. The transmission means has a power device driving a transmission shaft to rotate at a speed of 60 rpm to 600 rpm. One end of the transmission shaft penetrates into the mixing drum. A waterproof unit is provided between the transmission shaft and the mixing drum. The stirring pieces are assembled on the transmission shaft in the mixing drum. The stirring piece is formed into a plate. An outer surface of each stirring piece relative to its rotating direction is formed into an inclined surface. The outer end of each stirring piece is provided with an auxiliary stirring portion to face the inner surface of the mixing drum. The rotation of the stirring piece generates a centrifugal force to stir the concrete containing gravels.

Abstract: A modified asphalt Contactor reactor for blending and reacting asphalt cement and modifiers is described; for example, a vertically oriented vessel having an outer shell having an internal surface and an external surface, a lower end and a flat flanged top; an internal circulation tube having a base, a top and an outside surface, wherein the outside surface of the internal circulation tube and the internal surface of the outer shell forms an annulus; a heating jacket having heating oil inlet and a heating oil outlet coupled to the external surface of the outer shell for circulation of heating oil; and a hydraulic head assembly having an impeller coupled to the lower end the vertically oriented vessel wherein the impeller is located near the base of the internal circulation tube, wherein the impeller and the annulus are of sufficient size to facilitate the flow of high viscosity fluids.

Abstract: A mixing tool is provided for mixing, in a mixing container, plural materials including a first material and a second material. The mixing tool has a shaft and a first mixing member. The first mixing member has a visual reference for indicating when a predetermined volume of the first material is deposited in the mixing container.

Abstract: A sulfur-containing material in a melt state is stored in material hopper 1 heated to a temperature within a preset temperature range of which a lower limit is equal to or above a melting point of sulfur. The stored sulfur-containing material is sucked by pressure generators 2a, 2b and pulled out into cylinders 11a, 11b heated to a temperature within the preset temperature range. The pulled out sulfur-containing material is pushed out from the cylinders under predetermined pressure applied by the pressure generator, and thereafter, the resultant material is injected from injection port 24 into mold 5 having therein a cavity which can be hermetically sealed and the mold being heated to a temperature within the preset temperature range. The injection port of the mold after the sulfur-containing material is fully injected in the cavity is closed. By stopping heating of the mold, the sulfur-containing material injected in the cavity is slowly cooled.

Abstract: The disclosure relates to a method for effectively and efficiently adding sodium trimetaphosphate to a gypsum slurry. In one exemplary embodiment, the sodium trimetaphosphate is added at the same time as foam is added to the gypsum slurry through the foam waterline. In another exemplary embodiment, the sodium trimetaphosphate is added at the same time as additional water is added to the gypsum slurry through the gauging waterline. The sodium trimetaphosphate can be added to either or both waterlines in its dry form or in a diluted solution.

Abstract: A process employing a wet mixer having a vertical mixing chamber for forming a wet slurry of a cementitious powder and liquid. The vertical mixing chamber is designed to provide the required amount of mixing to provide thoroughly mixed, uniformly thin slurry within a mixing residence time that allows for adequate supply of slurry to ensure continuous operation of an associated cement panel production line. Gravity feed for supply of cementitious powder and water to the slurry mixing area of the chamber is also disclosed.

Abstract: A wet mixer apparatus and method for its use, the mixer having a vertical mixing chamber for forming a wet slurry of a cementitious slurry and water. The vertical mixing chamber is designed to provide the required amount of mixing to provide thoroughly mixed, uniformly thin slurry within a mixing residence time that allows for adequate supply of slurry to ensure continuous operation of an associated cement panel production line. Gravity feeding for separate supply of cementitious powder and water to the slurry mixing area of the chamber without pre-mixing of the powder and water is also disclosed.

Abstract: A portable assembly for mixing water with cement powder and dispensing produced paste into a predetermined area, comprising a removable mixer assembly including an elongated mixing shaft, means for generating and transmitting a rotational motion to the mixer assembly, an uprightly supported mixing body having a mixing chamber including an upper opening and inner space for the water and dry cement to be mixed and homogenized inside thereof and aided by the mixing shaft. Also including a discharging mechanism having fixed and movable grip members to be manually actuated, than in turn actuate a spring assembly and releases a closure member to permit the mixed homogenized paste to flow out of the mixing chamber. The discharging mechanism further includes a guiding plate assembly to prevent the over spillage of the produced cement paste and guide the discharging flow out directly into the selected area.

Abstract: An auger for a vertical livestock feed mixer having an open-top mixing tub is provided. The auger includes two flights to draw in feed components from the bottom of the mixer tub and move them to the top. The trailing edge of the upper auger flight includes an upraised portion to deflect feed components towards the sidewalls of the feed mixer. The leading edge of the lower auger flight includes a kicker plate on the topside of the flight to deflect feed components towards the centre of the auger.

Abstract: A portable concrete plant for producing ready mix concrete proximate to a location where the ready mix concrete is used. The portable concrete plant includes storage regions for storing components used in the ready mix concrete. The portable concrete plant also includes a slurry mixer for preparing slurry that is used in the ready mix concrete. The portable concrete plant further includes conveying systems for conveying the components from the storage regions and from the slurry mixer to a system discharge port.

Abstract: An apparatus for adding a coloring agent to a material used to manufacture brick includes an extrusion container having an opening defined in the sidewall thereof. A coloring agent supply communicates with the opening for delivery of the coloring agent to the interior of the container as brick making material passes through the container. A storage device stores the coloring agent supply amount data corresponding to a supply amount for each of a plurality of brick types, each of the plurality of brick types having a different appearance. A controller is adapted to control a supply of a coloring agent from said coloring agent supply into said extrusion container in accordance with a selected brick type. A computer can be connected to the controller for data transfer. Accordingly, the computer can be used as an interface between a user and the apparatus.

Abstract: An apparatus and methods for blending and for delivering additives, for example, in pelletised form, to form thin surface dressings for the pavement construction industry. One or more additives may be weighed, blended and transferred for combination of the blended pelletised additives into an aggregate and bitumen mix.

Abstract: A wheelbarrow with a mixing assembly for mixing aggregate building products. The wheelbarrow has a base assembly and an open hopper mounted on the base assembly. The mixing assembly has a mixing blade positioned within the hopper, and a motor. A motor housing is positioned under the hopper, within the base assembly, and houses the motor. A shaft extends from the mixing blade through the bottom surface of the hopper into the motor housing. The shaft connects the mixing blade with the motor, and allows for rotational movement of the blade to effect cutting grooves into the aggregate substances within the hopper when the motor is activated.

Abstract: A compression-paddle mixer has a compression paddle (1) that includes paddle blades (3) juxtaposed colinearly to a paddle rod (5). The paddle blades include one or more sets (2) of two paddle blades having channel-funneled orientation on paddle spokes (4) that are extended radially from the paddle rod. The channel-funneled orientation includes channel-funnel inlets (9) having inlet areas between leading-edges of sets of the paddle blades that are larger than inlet areas of channel-funnel outlets (11) between trailing-edges of the sets of the paddle blades in a direction of rotation of the paddle blades transmitted by rotation of the paddle rod. The compression paddle can be sized, shaped and structured for use with select sizes, shapes and structures of mix containers for select mixing applications.

Abstract: Apparatus for the rapid production of concrete having a grout slurry forming device, a cyclonic mixer for aggregate and a weighing device for feeding weighed amounts of aggregate to the cyclonic mixer. The slurry forming device including, subjecting fine particles in a liquid to the action of one or more rotating disc shaped blades, arranged to create within the slurry alternating areas of high and low pressures, thereby breaking up agglomerations. The cyclonic mixer includes, a hopper in which at least two conveyors simultaneously transport aggregate streams tangentially into, in opposite directions inducing helical mixing paths. The weighing device including, an aggregate weigher wherein a number of aggregate storage bins selectively releases aggregate onto a variable speed controlled conveyor. Intimately mixed concrete being formed from the simultaneous release of the grout slurry into the cyclonic mixer combining with the mixing aggregate.

Abstract: A porous paste, especially a plaster paste or slurry for producing sandwich-type plasterboard, is made in a disk-shaped mixer having a rotor rotatable in a mixing chamber by introducing compressed air or other pressurizable gas through a wall or bottom segment directly into the chamber so that the incoming pressurized gas meets the mixture with a shearing action along the wall or bottom.

Abstract: There is provided a forced mixer for mixing components, comprising a funnel-shaped mixing space having along its center axis (3) a coaxially mounted inner and outer mixing tool, the inner mixing tool (2) consisting of a screw (5) extending toward the outlet slide (6). For the forced mixer to be usable with a high efficency in particular as a concrete mixer, the outer mixing tool (8) comprises mixing shares or scrapers (9) glidingly moving along the mixing container surfaces (1) contacted by the mixed material.

Abstract: An improved structure of a cement mixing apparatus comprising a base frame, two supporting frames, a panel, a mixing cylinder and a transmission mechanism, characterized in that the base seat has a substantial square shaped structure having a plurality of mounting holes for screws; the supporting frame is a H-shaped structure with a plurality of mounting holes for screws to mount a reinforcing plate at the top end of the supporting frame to the base frame, the two supporting frames are mounted together with the reinforcing plate as a unit such that the base flames and two supporting frames are formed into a framework structure.

Abstract: An apparatus and method for blending dry comminuted materials which is particularly effective for comminuted materials having disparate physical properties such as density and particle size. The dry blending apparatus includes a substantially upright wall defining a blending enclosure, a feed mechanism for feeding dry comminuted materials into the blending enclosure, and a rotational distribution mechanism for distributing the dry comminuted materials onto the wall by causing the dry comminuted materials to fly outwardly by centrifugal force.

Abstract: A portable concrete plant for producing ready mix concrete proximate to a location where the ready mix concrete is used. The portable concrete plant includes storage regions for storing components used in the ready mix concrete. The portable concrete plant also includes a slurry mixer for preparing slurry that is used in the ready mix concrete. The portable concrete plant further includes conveying systems for conveying the components from the storage regions and from the slurry mixer to a system discharge port.

Abstract: A porous paste, especially a plaster paste or slurry for producing sandwich-type plasterboard, is made in a disk-shaped mixer having a rotor rotatable in a mixing chamber by introducing compressed air or other pressurizable gas through a wall or bottom segment directly into the chamber so that the incoming pressurized gas meets the mixture with a shearing action along the wall or bottom.

Abstract: A mixer including a mixing vat (2), a mixer rotor (8) rotatable by a drive motor (6) around an essentially vertical axis of rotation (10) and a first mixing tool (14) mounted on the mixer rotor (8) so as to rotate around a first axis. Additionally located on the mixer rotor (8) is at least one further mixing tool (24), the mixing tools extending from above down into the mixing vat (2) or into the mixed substance. In order to optimize thorough mixing of the substances being mixed with minimum expense for construction, the mixer rotor (8) is provided with a set of gears (22) by which the first mixing tool (14) and a second rotatable mixing tool (18) are coupled such that the rotational speed of the second mixing tool (18) is greater than the rotational speed of the first mixing tool (14) by a predetermined factor.

Abstract: An apparatus for mixing powdered or premixed drywall joint compound and water to form a joint compound mixture or slurry includes a portable container rig with a container, pumping components, and mixing components on a dolly. A mixing element rests within the container upon the container bottom, while a mixing element driver assembly that is adapted to rest upon the upper lip portion of the container engages the mixing element and rotates it for mixing purposes while at the same time raising it slightly. The pumping components may include various commercially available valves and pump outlets that facilitate the filling of various tape application tools, and one preferred embodiment includes remote control components featuring automatic pump turnoff. One embodiment includes a multifunction coupling assembly having an upper coupling component and two different lower components.

Abstract: An apparatus for making concrete is disclosed. The apparatus includes one or more measurement devices that is used to provide controlled quantities of at least cement and sand; a high intensity mixer that receives the controlled quantities of the cement and sand, mixes the controlled quantities of the cement and sand to produce grout, and outputs a flow of grout; and a controller coupled to the measurement devices and the mixer. The controller monitors and controls mixing energy applied by the mixer during mixing. In one embodiment, the mixing energy is altered by controlling the degree of opening of a discharge gate of the mixer. A concrete plant design including such an apparatus is also disclosed.

Abstract: An apparatus for mixing powdered or premixed drywall joint compound and water to form a joint compound mixture or slurry includes a portable container rig with a container, pumping components, and mixing components on a dolly that includes an arrangement for holding the mixing components in an elevated position. A mixing element rests within the container upon the container base, while a mixing element driver assembly that is adapted to rest upon the upper lip portion of the container engages the mixing element and rotates it for mixing purposes while at the same time raising it slightly. The pumping components may include various commercially available valves and pump outlets that facilitate the filling of various tape application tools, and one preferred embodiment includes remote control components featuring automatic pump turnoff.

Abstract: The method of treating an aqueous, cementitious slurry, to enhance fluidity, that includes providing a container for the slurry and effecting movement of the slurry via an impeller, in the container, and locating at least one vibrator in the interior of the vessel, and operating the vibrator to transmit vibration to the moving slurry.

Abstract: A heated kettle for melting and mixing a thermoplastic resin into a homogeneous mixture has a helically-formed agitator which rotates about a central shaft in close proximity to the internal wall of the kettle. Fixed to the shaft at approximately the center of the kettle is a cluster of radially extending paddles. The paddles and agitator have opposite pitch when the agitator and paddles are rotated, the resin circulates along the wall of the kettle and thence through a central region of the kettle. The circulation action serves to thoroughly melt and mix the resin into a homogeneous liquid mass.

Abstract: An apparatus for cement blending includes a pressure vessel for containing a slurry and an agitating member which mixes the slurry within the pressure vessel. The pressure vessel includes a first inlet for connection to a source of pressurized driving fluid and a first outlet through which the slurry can be discharged when the pressure vessel is pressurized by the driving fluid. The apparatus is capable of blending a thick slurry of water and cement. A vibrating mechanism vibrates the vessel to facilitate mixing of the slurry and discharge of the slurry from the vessel by the driving fluid.

Abstract: A materials mixer, suitable for mixing concrete, comprises a generally cylindrical housing (10) which houses a mixing chamber (15) consisting of an upper, dry mixing chamber portion (2), a central, wet mixing chamber portion (3) and a lower, discharge chamber portion (4). The materials mixer has an entrance (20) for materials to be mixed and an exit (25) for the complete mixture, between which are a plurality of rotating members (30, 40, 50, 60) which disrupt the flow of materials through the chamber (15) causing mixing of the materials. The shape of the mixing chamber is defined by a plurality of baffle plates (11, 12, 16) which help determine the path of the materials though the chamber.

Abstract: A mixer is disclosed which allows more effectively mixing and easy maintenance. The mixer can positively and effectively mix different kinds of concrete. an inside mixing blade 18 includes first and second mixing blade elements 19, 19each provided with a supporting member 18d for supporting mixing blades 18a. The two mixing blades 18a are each formed in helical configuration and has greater width. the first and second mixing blade elements 19, 19 are inserted to a shaft body 17a as well as a spacer 17a and prevented from coming off the shaft body 17a by a end plate 17b. The inside mixing blade 18 is formed in helical shape of substantially 360 .degree.. When any one of the mixing blades 18a is damaged, only the mixing blade element 19 having the damaged mixing blade 18a should be replaced with new one so that the replacement can be simply performed and the maintenance of the mixer 1 is improved.

Abstract: A container is provided for slurry; an impeller is provided to effect slurry movement in the container; and a vibrator is operated for transmitting sufficient vibration to the moving slurry to lower the water/cement ratio to a low level, and at a water temperature within a specified range. The location of vibration transmission from the vibrator can be adjusted along the wall of the container.

Abstract: The invention relates to a mixing apparatus comprising a mixing bowl (10) and a lid (70) for vacuum-sealing the mixing bowl (10), which lid is provided with a passage (84) for a mixing rod. The lid (70) is relatively rigid in the axial direction of the mixing bowl (10), whereas at least the portion of the lid (70) which surrounds the passage (84) is radially movable. (FIG. 3.

Abstract: An automatic cementing system and method are disclosed for precisely controlling the density of a slurry during a continuously mixed cement application. The system includes an input water line and a dry cement hopper for supplying water and dry cement, respectively, to a mixing chamber. The mixing chamber includes two chambers, Chamber A and Chamber B, for thoroughly mixing the water and cement together to form a cement slurry. Chamber B includes a level sensor for measuring the change in slurry level. The input line includes a pump for supplying the water to the mixing chamber, and a flow meter for measuring the rate at which the water is supplied. Similarly, the hopper includes a rotary valve for regulating the rate at which the dry cement is supplied to the mixing chamber and a speed sensor for measuring the speed of the rotary valve. A discharge line with a discharge pump and a discharge flow meter receives and discharges cement slurry.

Abstract: A cement mixer pivotably mounted on a linkage of an arm assembly of a heavy-duty machine, for example, an excavator or a shovel. The cement mixer includes a barrel, an agitator assembly rotatably mounted on the barrel and used to agitate materials to be mixed in the barrel, a mounting beam connecting the barrel to the linkage, a funnel mounted on the mounting beam and positioned above the barrel and used to receive the materials to be mixed and a weight measuring device provided on the mounting beam and used to measure the weight of the materials received in the funnel.

Abstract: The invention provides apparatus for use in the preparation of gypsum products such as plasterboard from foamed gypsum plaster slurry. The apparatus comprises a first mixing chamber 10 containing a high speed rotor 14 and inlets 18, 19 for gypsum plaster and water. The initial dispersion of gypsum plaster and water foamed in the first chamber passes directly and continuously into a second chamber 25 containing a low speed rotor 29. Preformed foam is introduced into the second chamber through an inlet 33, and the foamed slurry product leaves the second chamber through an outlet 34, to be formed into plasterboard.

Abstract: Improved paddle mixer, including a stationary drum solid to a support frame, with a vertical shaft engaged with a motor-reducer unit and provided with a plurality of transverse arms to each of which at least a paddle is fixedly or otherwise rotatively connected, wherein each of the paddles, being fixed with respect to the relevant support arms, is made up of two like plates disposed at the free end of the corresponding arm and between which a rubber element is interposed so that, by the rotation of the shaft, that is, during the blending of the materials introduced inside the drum, the rubber element provides for scraping the side or respectively bottom wall of the drum.

Abstract: A mounting assembly for the primary mixing paddles in a pan-type mixer includes a single bolt paddle support arm mounting and adjustment device, and a two bolt paddle mounting feature, both of which are constructed and located to provide reliable adjustability and demountability and to protect the assemblies against the ingress of contaminants and abrasive wear from the materials being mixed. The single bolt clamping device also provides simple vertical adjustment of the paddle height in a manner which retains the adjustment mechanism enclosed against the entry of contaminants. The two bolt paddle mounting assembly encloses both threaded connections inside the body of the paddles, and includes a protective enclosing shroud and positions the exposed bolt heads at the back of the assembly out of the direct path of abrasive materials.