# US 5,344,473 A · Apparatus for the deposition of melamine

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- Number: US 5,344,473 A
- Document ID: US5344473A
- Status: Granted
- Kind: A
- Application number: 08/038,276
- Filed: 1993-03-29
- Granted: 1994-09-06
- Earliest claimed: 1992-03-30
- Assignees: Chemie Linz Gesellschaft m.b.H.
- Inventors: Gerald Szolgyenyi; Peter Hildebrand
- Web page: https://patentgrep.com/patent/US5344473A

## CPC

- B01D 53/72: Organic compounds not provided for in groups B01D53/48 - B01D53/70, e.g. hydrocarbons
- B01D 53/74: General processes for purification of waste gases; Apparatus or devices specially adapted therefor (B01D53/92 takes precedence)
- B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28)

## Abstract

An apparatus is provided for the deposition of melamine from hot reaction gases into a wash liquid. The apparatus includes a heated gas feed pipe for introducing the hot reaction gases into an absorption pipe. The gas feed pipe is provided with an extension nozzle, the lower end of which projects coaxially into the absorption pipe. The upper part of the absorption pipe and the gas feed pipe are surrounded by a closed container which serves as a storage vessel for wash liquid. The inner wall of the absorption pipe is constantly washed by flowing wash liquid from the closed container.

## Claims

### Claim 1

A melamine deposition apparatus comprising:
an absorption pipe having an open upper end;
a substantially closed container surrounding said open upper end of said absorption pipe;
a heatable gas feed pipe mounted in said container for feeding melamine-containing reaction gases downwardly into said open upper end of said absorption pipe;
a wash liquid feed pipe opening into a lower portion of said container for feeding wash liquid into said container to a level just above a lip of said open upper end of said absorption pipe, such that the wash liquid fed into said container can flow as a continuous film over said lip and down along an inner wall of said absorption pipe;
an inert gas feed pipe opening into an upper portion of said container for feeding inert gas into said upper portion of said container; and
an extension nozzle mounted to and extending downwardly from a lower end of said gas feed pipe and into said open upper end of said absorption pipe.

### Claim 2 (depends on 1)

A melamine deposition apparatus as recited in claim 1, further comprising
a heater mounted in said upper portion of said container adjacent said heatable gas feed pipe.

### Claim 3 (depends on 2)

A melamine deposition apparatus as recited in claim 2, wherein
said heater comprises a heating means for heating said heatable gas feed pipe and said upper portion of said container.

### Claim 4 (depends on 3)

A melamine deposition apparatus as recited in claim 3, wherein
said heating means is operable to heat said heatable gas feed pipe and said upper portion of said container electrically or with heating liquid.

### Claim 5 (depends on 2)

A melamine deposition apparatus as recited in claim 2, wherein
said heater comprises a heatable jacketed pipe mounted about an upper portion of said heatable gas feed pipe and projecting down into said container.

### Claim 6 (depends on 1)

A melamine deposition apparatus as recited in claim 1, further comprising
a constriction element mounted in said absorption pipe to reduce a cross-sectional size of said absorption pipe at a location adjacent a lower tip of said extension nozzle.

### Claim 7 (depends on 6)

A melamine deposition apparatus as recited in claim 6, wherein
said constriction element has an inside cross-sectional area about 50 to 80 percent smaller than an inside cross-sectional area of said absorption pipe at said constriction element.