Oxalic acid feeder

Abstract

The invention discloses an oxalic acid feeding machine. The oxalic acid feeding machine comprises a charge mechanism, a feeding mechanism and a gas transmission mechanism, wherein the charge mechanism comprises a funnel-shaped storage box, a box cover covering the upper port of the storage box in a sealing manner, a vertical barrel-shaped connection piece communicating with the lower port of the storage box, and a horizontal sleeve arranged at the bottom end of the connection piece, a filler connector is arranged in the box cover, and a discharge port communicating with the connection piece is arranged in the upper end surface of the horizontal sleeve; the gas transmission mechanism comprises a sublimation box, heating wires arranged at the bottom in the sublimation box, and a partition covering the heating wires, a gas inlet connector used for connecting nitrogen gas and a gas outlet connector connected with the interior of a degreasing furnace through a gas channel are arranged in the sublimation box respectively, a feeding port is formed in one side of the sublimation box, and one end of the sleeve is installed on the feeding port in a communication manner; and the feeding mechanism comprises a movable block movably connected in the sleeve in an insertion manner, and a receiving hole penetrating through from top to bottom is formed in one end facing the feeding port, of the movable block. The oxalic acid feeding machine disclosed by the invention realizes supply of a gaseous oxalic acid catalyst, so that the degreasing furnace decomposes polyformaldehyde by taking gaseous oxalic acid as the catalyst.

Description

technical field [0001] The invention relates to an auxiliary device for a degreasing furnace, and more particularly to an oxalic acid feeder used in metal injection molding and ceramic injection molding to catalyze the degreasing furnace. Background technique [0002] The process principle of catalytic degreasing is to use the characteristics of solid polyoxymethylene (POM) to quickly crack into gaseous formaldehyde molecules under an acidic atmosphere at a certain temperature (about 100 ° C), in which the acid exists as a catalyst. Its cracking formula is as follows: [0003] (CH 2 O) n (acidic solution)—→nCH 2 o [0004] At present, the catalyst commonly used in catalytic degreasing process is nitric acid (HNO 3 ), a diaphragm pump or plunger pump is generally used to complete the delivery of nitric acid to the degreasing furnace. The structure principle of plunger pump is as follows: figure 1 As shown, when the eccentric wheel 71 controls the piston 72 to move to t...

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Problems solved by technology

[0008] Therefore, it is not conducive to the application of catalytic degreasing technology to these metal powders that are easily oxidized by nitric acid

[0009] 2. Nitric acid produces a large amount of nitrogen oxides, which cannot be effectively decomposed and pollutes the atmosphere. There is HNO in the exhaust gas 3 and NO x , is one of the causes of acid rain, which is harmful to the environment and can cause pollution to water bodies, soil and the atmosphere

[0010] 3. The limitation of this kind of acid pump, the plunger pump is only limited to transport liquid, and cannot transport gas or solid

[0012] 1. The existing solid-state feeder occupies a large volume, and the structure and precision are often not ideal, especially the lateral and radial gaps are large, often causing problems such as material leakage and running, and cannot stably control the instantaneous feeding amount ; and the adjustment range of the feeding amount is relatively narrow, which can only realize the transportation of a large amount of powder, and cannot realize quantitative and micro-quantity transportation

[0013] 2. Because oxalic acid is very easy to absorb water and crystallize, it is easy to form agglomerates, and it is easy to stay in the channel during transportation, which may block the channel and affect production. It is not suitable to use the existing feeder to transport

[0014] 3. The existing gaseous conveying device cannot maintain high-temperature operation, because oxalic acid begins to sublimate at 100°C, so it is not suitable to use traditional gaseous conveying device, and the traditional gaseous conveying device only realizes a large amount of conveying, and cannot realize quantitative conveying

[0015] 4. The existing gaseous conveying devices use air compressors to complete the conveying, and a large amount of air will flow in immediately, because the catalytic degreasing process of metal injection molding and ceramic injection molding cannot have air inflow, otherwise serious safety accidents will occur. Therefore, the air compression method cannot be used for gaseous transportation; moreover, it must be completely sealed and airtight, which cannot be achieved by existing transportation devices.

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