RU2111065C1 - Apparatus for applying powder materials onto articles - Google Patents

Abstract

FIELD: apparatuses for applying polymeric protective coatings of powder materials onto articles in electrostatic field; may be used for applying corrosion-resistant coats onto inner and outer surfaces of tubes. SUBSTANCE: apparatus includes feeding hopper consisting of two parts. One of parts is in the form of stationary filling hopper. Apparatus also includes unit for feeding powder material, sprayer and high voltage power source. Second part of feeding hopper is in the form of cylindrical drum rotatably mounted on axle inclined relative to horizontal plane. Stationary hopper is arranged in cylindrical drum. Apparatus provides uniform and constant feed of powder material to suction-off ejector of feeding unit and further to spraying head due to prevention of material lumping, especially of hard-to-pour fluoropolymeric materials. EFFECT: enhanced efficiency. 1 dwg

Description

 The invention relates to devices for applying polymer protective coatings of powder materials to products in an electrostatic field and can be used to obtain anti-corrosion coatings on the outer and inner surfaces of pipes.

 A device for coating of dispersed polymeric materials is known comprising a feeder hopper made of two elements, one of which is a fixed hopper, and the second is a pseudo-deposition chamber, a powder material supply unit, a sprayer and a high voltage source.

 This device, although it allows you to use a wide range of materials and improve the quality of the applied layer, however, it does not prevent clumping of powder materials.

 The technical task of the invention is to prevent clumping of powder materials.

 The problem is solved due to the fact that in the device for applying powder materials to products containing a hopper-feeder, consisting of two elements, one of which is made in the form of a fixed bulk hopper, a powder material supply unit, a sprayer and a high voltage source, according to the invention another element of the hopper-feeder is made in the form of a cylindrical drum placed on the axis at an angle to the horizontal plane with the possibility of rotation, while the stationary bulk hopper is placed in cylin driche drum.

 The proposed device allows you to prevent clumping of powder materials by creating a pseudo-fluid layer of powder by performing one of the elements of the hopper-feeder in the form of a cylindrical drum placed on the axis at an angle to the horizontal plane and its rotation at a constant speed. The angle of inclination of the drum and its rotation at a certain selected speed leads to a breakdown in the bonds between the particles due to the pouring of the powder in a complex ellipsoidal shape without breaking the continuity of the layer and its collapse, prevents the formation of voids, which ensures uniform and constant flow of powder without lumps and voids to the suction ejector feed unit, and then to the spray head.

 The fixed bulk hopper continuously feeds the powder of the cylindrical drum and prevents the formation of lumps by pouring powder into the rotating powder mass of the drum.

 The device has implemented a fundamentally new approach to the formation of a fluidized state by using a cylindrical drum rotating at an angle to the horizontal plane and a metered supply of powder using an unregulated ejection unit introduced by the suction end into the fluidized bed of the cylindrical drum. This ensures the creation of a finely dispersed air-powder mixture due to the ejected angle and its metered supply without clumping through the supply pipe to the spray head by introducing air under pressure, which improves productivity.

 The drawing shows the proposed device, consisting of a bulk hopper 1, a cylindrical drum 2, rotating with an electric motor 3, an unregulated ejector 4, a spray head 5, an electric atomizer 6, which is powered by a high-voltage source 7. The polymer powder is sprayed onto the product 8.

 The device operates as follows.

 Powder material is poured into the cylindrical drum 2 through the bulk hopper 1 and rotated using an electric motor 3. The formed fluidized bed is sucked out using an unregulated ejector 4, and the formed air-powder mixture moves in the spray head 5, in which it is charged from the electrode 6, which is powered by high voltage source 7 and is sprayed onto the inner and outer surface of the product 8.

The coating was exposed to the outer surface of the pipes, which were moved rotationally-translationally relative to the developed device for applying polymer materials. The pipes were coated with a fluoropolymer composition 40-LD-1. The powder composition was loaded into a bulk drum (feeder), the cylindrical drum 2 was rotated from the electric motor 3. The loose loose powder mass under the air pressure of 1.5 kg / cm ² supplied through an uncontrolled ejector 4 fell through the spray head 5, the electrode-atomizer 6, received electrical power from a high voltage source 7, to the inner surface of the product 8.

 The proposed device allows for a uniform and constant supply of powder material to the suction ejector of the supply unit and further to the spray head by preventing clumping, especially of hard-flowing materials (e.g., fluoropolymer powders), and to increase productivity.

 The device can be used for coating pipes in the oil, gas, chemical and automotive industries.

Claims (1)

 A device for applying powder materials from an article containing a hopper-feeder, consisting of two elements, one of which is made in the form of a fixed bulk hopper, a powder material supply unit, a sprayer and a high voltage source, characterized in that the other element of the hopper-feeder is made in in the form of a cylindrical drum placed on an axis at an angle to the horizontal plane with the possibility of rotation, while a stationary bulk hopper is placed in a cylindrical drum.