US 4,370,944 A · Apparatus for coating the inner surface of long tubes of small diameter

Abstract

A coating method and apparatus for coating the inner surface of a long tube of small diameter, specifically tubes for a condenser. The coating is a type of spray coating wherein a long flexible supply hose, longer than the long tube to be coated, is reciprocated in the long tube with a spray nozzle attached to the tip thereof for spraying the paint by the action of compressed air, from one end of the long tube to the other end thereof while spraying the paint in atomization. The long flexible supply hose of double structure or sometimes of triple structure is composed of a short heating pipe portion adjacent to the spray nozzle and a long flexible hose portion. The paint and compressed air supplied through separate passages in the supply hose are heated to a predetermined temperature by heating means, for example, a sheathed electrical heater wound about an inside pipe of the heating pipe portion upstream of where the paint is sprayed.

Claims12

Dependent claims

A coating apparatus for coating the inner surface of a long tube of small diameter by spraying a paint in atomization while being shifted from one end opening to the other end opening thereof comprising:

a supplying hose which is longer than said long tube for being inserted into and drawn back from said long tube and provided therein with respective passage for supplying a paint and compressed air;
a spray nozzle attached to the tip of said supplying hose for spraying the paint in atomization supplied from outside of said long tube;
and
heating means disposed at least in the neighborhood of the attaching portion of said nozzle to said supplying hose for heating the paint and the compressed air to a predetermined temperature.

1 more element

Apparatus for coating the inner surface of a long tube of small diameter such as a condenser tube by spraying atomized paint while the apparatus is shifted within a said long tube from one end opening to the other end opening thereof, said apparatus comprising:

a spray nozzle for atomizing and spraying said paint by the action of compressed air;
supplying means for supplying simultaneously but separately the paint and the compressed air to said spray nozzle,
means to attach said spray nozzle to an end of said supplying means to permit said nozzle to be inserted into and drawn to and fro inside of said long tube;
and
heating means for heating said paint and said compressed air which have been led to said spray nozzle to a predetermined temperature, said heating means being disposed within said supplying means and located in the vicinity, at least at one end thereof, of the attaching means between said nozzle and said supplying means;
whereby said paint and said compressed air are separately heated to said predetermined temperature before they are combined and sprayed onto said tube from said spray nozzle.

3 more elements

Dependencies are inferred from the claim text.

Apparatus for coating the inner surface of long tubes of small diameter

Life of this patent

Apparatus for coating the inner surface of long tubes of small diameter

Life of this patent

Abstract

Claims12