Phosphoric acid recovery system produced by hot method

Abstract

The utility model relates to phosphoric acid production, in particular to a phosphoric acid recovery device produced by a hot method. Phosphoric acid absorption and recovery problems are solved. The phosphoric acid recovery system comprises an absorption tower and a distillation still, a gas inlet pipe is arranged on the side wall of the bottom of the absorption tower, a gas outlet pipe is located at the top of the absorption tower, an annular pipeline is arranged on the side wall of the absorption tower, a plurality of branch pipes are evenly arranged on the annular pipeline in an up-down staggered mode, and two sets of upward and downward branch pipes are formed; the branch pipes in each direction are evenly distributed, L-shaped connecting pipes are arranged on the branch pipes, a support rod is arranged at the position, corresponding to the upward branch pipes, of the annular pipeline, cylindrical connectors are arranged on the upper side wall of the absorption tower, each branch pipe corresponds to one cylindrical connector, threaded holes are formed in flanges at the ends, corresponding to the cylindrical connectors, of the connecting pipes, and the threaded holes are communicated with the connecting pipes. An acid spraying pipe is screwed on the threaded hole and extends into the tower, a spray head is arranged at the front end of the acid spraying pipe, and the spray direction of the spray head is inclined upwards. The transformation cost is low, the assembly is convenient and fast, the later maintenance cost is low, and the cooling efficiency is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to phosphoric acid production, especially the phosphoric acid recovery device of hot method production. BACKGROUND

[0002] Hot method phosphoric acid production dispenses with a large amount of chemical medicine, and thus has less influence on the environment. The product produced by the hot method is also relatively pure, but the production process is more complex than the wet method, and the cost is relatively high. After yellow phosphorus burns, it generates phosphorus pentoxide, and there is an insufficient absorption condition in the absorption filtration. The existing recovery device is small, and for large-capacity production conditions, the recovery device is enlarged and raised, and the top nozzle spray circle is not easy to cover the entire tower diameter, which affects the spraying effect and leads to poor effect. SUMMARY

[0003] In order to overcome the above-mentioned shortcomings of the prior art, the utility model provides a device for recovering phosphoric acid with large capacity and volume, which ensures the recovery rate of phosphoric acid under the premise of increasing the volume, and at the same time ensures the recovery of phosphorus pentoxide in the hot method production of phosphoric acid.

[0004] The utility model adopts the technical scheme that the technical problem thereof is solved: the phosphoric acid recovery system of hot method production, including the absorption tower and the distillation kettle, the bottom side wall of absorption tower is equipped with the air inlet pipe, the air outlet pipe is located in the top of absorption tower, the side wall of absorption tower is equipped with one annular pipeline, the annular pipeline is evenly provided with a plurality of branch pipes up and down staggered, forms two groups of branch pipes respectively upwards and downwards, the branch pipe in each direction is evenly distributed, is equipped with L shape connecting pipe on the branch pipe, the annular pipeline where upwards branch pipe corresponds is equipped with one support rod, and the lower end of support rod is placed on the inspection platform.

[0005] The upper side wall of the absorption tower is provided with a cylindrical interface, each branch pipe corresponds to a cylindrical interface, and a flange is arranged on the cylindrical interface; the branch pipe and the cylindrical interface are respectively provided with a flange, the connecting pipe is respectively provided with a flange matched with the corresponding end, the flange on one end of the connecting pipe corresponding to the cylindrical interface is provided with a threaded hole, the threaded hole is communicated with the connecting pipe, a phosphoric acid spraying pipe is screwed on the threaded hole, the phosphoric acid spraying pipe extends into the tower, a spray head is arranged at the front end of the phosphoric acid spraying pipe, the spray direction of the spray head is inclined upward, and the annular pipeline is connected with the spray liquid sent by the water pump.

[0006] The bottom of the absorption tower is provided with a liquid discharge pipe communicated to the liquid inlet pipe on the side wall of the distillation kettle, the air outlet pipe at the top of the distillation kettle is connected to the condenser and then flows into the spray liquid mixing box, and the bottom of the distillation kettle is provided with a material discharge port.

[0007] In a more preferred embodiment, the two groups of height different phosphoric acid spraying pipes, the length of the upper group of phosphoric acid spraying pipes is longer than that of the lower group of phosphoric acid spraying pipes, and is closer to the axial position of the tower. The upper and lower groups of phosphoric acid spraying pipes form an arc-shaped splashing area, which improves the spray recovery effect.

[0008] More preferably, a vacuum pump is installed on the outlet pipe of the distillation kettle. The outlet pipe is actively discharged by the vacuum pump, which helps to improve the cooling efficiency of the steam.

[0009] The utility model has the advantages that: the spray pipeline is arranged on the side wall of the absorption tower, effectively solves the problem of large absorption tower body and unsatisfactory spraying effect, and a plurality of groups of spray pipelines are arranged on the tower body according to actual needs, compared with the top spraying structure, the effect is better, and the layout is more reasonable. The spray pipe and the auxiliary structure are also low in cost for the existing tower body transformation, convenient and fast to assemble, and low in maintenance cost in the later period. The steam generated by the distillation kettle is discharged by the vacuum pump, the discharged steam temperature is slightly low, the cooling efficiency is improved, the steam water is liquefied by cooling, although the water is cooled, the water still has a certain temperature, part of the water is returned to the spray liquid in the absorption tower, BRIEF DESCRIPTION OF DRAWINGS

[0010] Figure 1 It is a structural schematic view of the utility model.

[0011] Figure 2 It is a related structure schematic view of the spray pipe of the utility model.

[0012] Figure 3 It is a sectional view of the spray tower of the utility model.

[0013] The absorption tower 1, the inlet pipe 101, the outlet pipe 102, the liquid discharge pipe 103, the distillation kettle 2, the outlet pipe 201, the annular pipeline 3, the supporting rod 31, the branch pipe 4, the L-shaped connecting pipe 5, the cylindrical interface 6, the flange 7, the acid spraying pipe 8, the spray head 9, the condenser 10, the spray liquid mixing box 11, the inspection platform 12 and the vacuum pump 13. DETAILED DESCRIPTION

[0014] The utility model will be further described below in combination with the drawings and examples.

[0015] Wherein, same parts are indicated by same reference numerals. It should be noted that the words "front", "back", "left", "right", "up" and "down" used in the following description refer to the directions in the drawings, and the words "in" and "out" refer to the directions towards or away from the geometric center of a particular component, and the drawings are in a very simplified form and use non-precise ratios, only to facilitate, clearly assist in the purpose of explaining the embodiments of the utility model. EMBODIMENT

[0016] As Figure 1As shown, the heat production of phosphoric acid recovery system, including absorption tower 1 and distillation kettle 2, absorption tower 1 bottom side wall on the gas inlet pipe 101, gas outlet pipe 102 is located in the top of absorption tower 1, absorption tower 1 side wall is equipped with a ring pipe 3, ring pipe 3 up and down staggered evenly provided with a plurality of branch pipe 4, form respectively to the upward and downward two groups of branch pipe 4, each direction of branch pipe 4 is evenly distributed, branch pipe 4 is equipped with L-shaped connecting pipe 5, upward branch pipe corresponding ring pipe 3 is equipped with a support rod 31, support rod 31 lower end is placed on the inspection platform 12.

[0017] As shown in the figure, Figure 2 The upper side wall of the absorption tower 1 is provided with a cylindrical interface 6, each branch pipe 4 corresponds to a cylindrical interface 6, and the cylindrical interface 6 is provided with a flange 7; the branch pipe 4 and the cylindrical interface 6 are respectively provided with a flange 7, the connecting pipe 5 is respectively provided with a flange 7 matched with the corresponding end, the flange on one end of the connecting pipe 5 corresponding to the cylindrical interface is provided with a threaded hole, the threaded hole is communicated with the connecting pipe 5, a spray acid pipe 8 is screwed on the threaded hole, the spray acid pipe 8 extends into the tower, the front end of the spray acid pipe 8 is provided with a spray head 9, the spraying direction of the spray head 9 is inclined upward, the ring pipe 3 is connected to the spraying liquid in the spraying liquid mixing box through the water pump 9, because the heights of the two groups of connecting pipes are different, two groups of spraying acid pipes 8 with different heights are formed, the length of the upper group of spraying acid pipes 8 is longer than that of the lower group of spraying acid pipes 8, which is closer to the axial position of the tower, the two groups of spraying pipes form an arc-shaped spraying area, which improves the spraying recovery effect.

[0018] The bottom of the absorption tower 1 is provided with a liquid discharge pipe 103 connected to the liquid inlet pipe on the side wall of the distillation kettle 2, the gas outlet pipe 201 on the top of the distillation kettle 2 is connected to the condenser 10 and then flows into the spraying liquid mixing box 11, a vacuum pump 13 is installed on the gas outlet pipe of the distillation kettle 2, the gas outlet pipe is actively discharged by the vacuum pump, which is beneficial to improve the cooling efficiency of the steam. The bottom of the distillation kettle 2 is provided with a material discharge port.

[0019] Working principle: burning yellow phosphorus produces phosphorus pentoxide gas, which enters the absorption tower through the gas inlet pipe, the water pump starts to supply weak acid spraying liquid into the ring pipe, the spraying liquid in the ring pipe passes through the branch pipe, the L-shaped connecting pipe and the spraying pipe in turn to reach the spray head, the spray head produces atomization effect, the spraying liquid is released in the absorption tower, the spraying liquid fully contacts with the phosphorus pentoxide gas to become phosphoric acid, which is settled at the bottom of the absorption tower. The spraying pipe system can be set at different heights of the absorption tower according to actual needs, even multiple groups can be set to meet different absorption needs, and it can also be used on the old absorption tower, the whole structure is more combined, and the transformation cost is low.

[0020] The sprayed phosphoric acid enters the distillation kettle to remove water, the discharged water is cooled and then returns to the spraying liquid mixing box, leaving some residual heat for the spraying liquid, which helps to improve the spraying absorption effect of phosphorus pentoxide.

[0021] For the sake of clarity, not all of the structural and functional features of an actual implementation are described in this description below because they can hinder comprehension of the application by one skilled in the art. It should be appreciated that in the development of any such actual implementation, numerous implementation-specific decisions must be made in order to achieve the developer's specific goals, such as compliance with application- and business-related constraints, which will vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.

Claims

1. A phosphoric acid recovery system produced by thermal process, comprising an absorption tower and a distillation vessel, characterized in that: An inlet pipe is located on the bottom side wall of the absorption tower, and an outlet pipe is located at the top of the absorption tower. A ring-shaped pipe is located on the side wall of the absorption tower, with several branches evenly distributed vertically to form two sets of branches, one upward and one downward. The branches in each direction are evenly distributed, and L-shaped connecting pipes are provided on the branches. A support rod is provided at the ring-shaped pipe corresponding to the upward branch, and the lower end of the support rod is placed on the inspection platform. A cylindrical interface is provided on the upper side wall of the absorption tower, with each branch corresponding to a cylindrical interface. A flange is provided on the cylindrical interface. Flanges are provided on the branch and cylindrical interface respectively. Flanges are provided at both ends of the connecting pipe. A threaded hole is provided on the flange at the cylindrical interface end of the connecting pipe, which communicates with the connecting pipe. An acid spraying pipe is screwed onto the threaded hole and extends into the tower. A nozzle is provided at the front end of the acid spraying pipe, and the spraying direction of the nozzle is inclined upward. The spraying liquid delivered by a water pump is connected to the ring-shaped pipe. The bottom of the absorption tower is equipped with a drain pipe that connects to the inlet pipe on the side wall of the distillation kettle. The outlet pipe at the top of the distillation kettle is connected to the condenser and flows into the spray liquid mixing tank. The bottom of the distillation kettle is equipped with a material outlet.

2. The phosphoric acid recovery system produced by the thermal method as described in claim 1, characterized in that: The two sets of acid spray pipes at different heights have the upper set being longer than the lower set and closer to the center of the tower.

3. The phosphoric acid recovery system produced by the thermal method as described in claim 1 or 2, characterized in that: A vacuum pump is installed on the gas outlet pipe of the distillation vessel.

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