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: In a turbo, pump according to the present invention, blades 3e and a shroud 3f are continuously formed with a boss 3c of a turbine wheel 3, a meridian plane configuration of the shroud 3f is formed as an concave arcing rotatable surface. A boss shroud 3f.sub.1 is formed substantially parallel to the axis of rotation O. A portion 3e.sub.2 of a blade outlet edge 3e.sub.1 is smoothly continuous to the boss shroud 3f.sub.1 and largely projects downstream. A portion 3e.sub.3 of the blade outlet edge 3e.sub.1 is formed substantially perpendicular to the axis of rotation O. The blade outlet edge 3e.sub.1 is formed with a smooth arc-like curve projecting convexly downstream between the portion 3e.sub.3 and the portion 3e.sub.2. An angle of the blade outlet edge 3e.sub.1 is set to an angle of substantially 0.degree. at the portion 3e.sub.2 of the blade outlet edge 3e.sub.1 and to substantially the conventional degree of angle at the portion 3e.sub.3 of the blade outlet edge 3e.sub.1.

Abstract: An impeller in a water pump for circulation of cooling medium in a cooling system of an engine has a shroud with a shroud end to which the edges of the blade inlets are attached and which is formed in the cylindrical configuration substantially parallel to the rotary shaft. Each of the edges of the blade inlets is shaped so that it is continuously smooth from a shroud end surface at the inlet side thereof and extends upstream in the axial direction, while each of the edges of the blade inlets at the side of a casing extends substantially perpendicularly to the rotary shaft. The edge of the blade inlet attached to the cylindrical shroud end and the edge of the blade inlet at the casing side being connected therebetween by a smooth arc-like curve projecting convexly upstream. The inlet angle of the blade is set to substantially 0.degree. at the inlet edge at the shroud end and to an angle calculated substantially on the basis of the conventional design at the inlet edge at the casing side.

Abstract: A turbo pump is provided with an impeller having a volute casing for a diffuser type casing. The configuration of a meridian section of the impeller shroud at the side of a boss is made as a concave arch-like surface of revolution. The shroud at the side of the blade inlet is cylindrical and substantially parallel to the shaft about which the impeller turns. Each of the blades of the impeller is so shaped that the edge of the blade inlet projects toward the impeller eye and is smoothly connected to the surface of the shroud. The inlet angle of the blade is as small as possible.

Abstract: A method for production of a heat exchanger is disclosed, where a powder flux is applied in a process of soldering a heat exchanger core of aluminum. An annular groove is formed in a seat plate. Measures are taken for preventing wetting of the annular groove of the seat plate when sprayed with the water on the preassembled core, such that a non-corrosive flux would not adhere to the annular groove of the seat plate. Water is sprayed in the form of a mist on a preassembled heat exchanger core through plurality of spray nozzles. The annular grooves of the seat plates are thoroughly dried after the application of water for attaining a perfect absence of residual non-corrosive flux in the annular grooves of the seat plates. A non-corrosive flux powder is sprayed onto the preassembled heat exchanger core of aluminum with a powder spray gun. The non-corrosive flux is caused to adhere fast to the portion wetted with the water.

Abstract: A method of applying a material of particulate form to the surface of an object by using a liquid, wherein the liquid is applied to the surface of the object to provide a film of the liquid thereon, and then the material of particulate form is applied to the film of the liquid on the surface of the object. Excess liquid may be removed from the surface of the object by using a jet of air current before the material of particulate form is applied to the film of the liquid on the surface of the object.

Abstract: A centrifugal pump including a stationary guide vane secured to a casing, and a centrifugal impeller arranged for rotation in the casing in a position adjacent the stationary guide vane. The centrifugal impeller has at least one blade wound in convolutions on a peripheral surface of a hub and having a blade inlet surface substantially perpendicular to the axis of rotation of the impeller and a fluid flow entrance surface substantially parallel to the blade inlet surface. The blade is wound in a suitable number of convolutions extending from an inlet to an outlet on the hub and is forwardly inclined toward the axis of rotation of the impeller at an increasingly greater angle in going from the inlet toward the outlet, so as to produce centrifugal forces at the outlet. The centrifugal impeller has a high head which has been beyond the power of axial impellers to achieve.

Abstract: A centrifugal pump capable of rotating in a normal direction while enabling a fluid to flow in a normal direction and rotating in a reverse direction while enabling the fluid to flow in the reverse direction without having its pumping efficiency dropping to a lower level in a reverse rotation mode than in a normal rotation mode. The pump includes two pump casings each having an inlet and outlet portion extending tangentially of each pump casing and connected together through an intermediate casing to provide a unitary structure in which the two pump casings are located concentrically in face-to-face relation, and an impeller having a helical blade extending axially from one zone in one pump casing into another zone in the other pump casing for rotation along the center axis of the pump. The impeller has a minimum outer diameter at the center of its center axis and includes portions each flaring in one of axial opposite directions in the form of a cone.