A zero-emission system for pre-coated and mid-coated wastewater

Abstract

The present invention discloses a zero-emission system for precoating and intermediate coating wastewater, which includes a precoating unit and an intermediate coating unit, as well as a vibrating screen, a wastewater recovery tank and a water pump connected in sequence; the precoating unit includes a precoating preparation tank, a precoating storage tank, a first discharging pump, a precoating feeding tank, a second discharging pump, a precoating pressure screen and a precoating coater connected in sequence; the intermediate coating unit includes an intermediate coating preparation tank, an intermediate coating storage tank, a third discharging pump, an intermediate coating feeding tank, a fourth discharging pump, an intermediate coating pressure screen and an intermediate coating coater connected in sequence; the sewage discharge pipes of the precoating unit and the intermediate coating unit are respectively connected to the vibrating screen. In actual use, the wastewater generated by the precoating unit and the intermediate coating unit is discharged to the vibrating screen, and can be recycled after treatment, achieving the purpose of energy conservation, environmental protection and clean production.

Description

Technical Field

[0001] The invention relates to the technical field of papermaking, and in particular to a pre-coating and mid-coating wastewater zero-discharge system. Background Art

[0002] The front side of whiteboard paper usually needs to be pre-coated and mid-coated. When paper breaks, stops or quality is abnormal, a certain amount of wastewater will be discharged. In addition, regular cleaning of equipment will also discharge a certain amount of wastewater. In the prior art, these wastewaters are directly discharged and sent to the wastewater treatment section of the factory for centralized treatment before being discharged. However, this may cause wastewater leakage, resulting in safety and environmental accidents, increase wastewater treatment costs, and waste precious water resources. In view of the above technical problems, the present invention proposes a pre-coating and mid-coating wastewater zero discharge system, which can recycle the wastewater generated by the pre-coating process and the mid-coating process to achieve the purpose of energy saving and environmental protection.

[0003] It can be seen that the existing technology still needs to be improved and enhanced. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, the purpose of the present invention is to provide a pre-coating and mid-coating wastewater zero discharge system, aiming to solve the technical problem that the wastewater generated by the pre-coating process and the mid-coating process in the prior art cannot be recycled.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A pre-coat and mid-coat wastewater zero discharge system comprises a pre-coat unit and a mid-coat unit, and a vibrating screen, a wastewater recovery tank and a water pump connected in sequence; the pre-coat unit comprises a pre-coat preparation tank, a pre-coat storage tank, a first discharge pump, a pre-coat supply tank, a second discharge pump, a pre-coat pressure screen and a pre-coat coating head connected in sequence; the mid-coat unit comprises a mid-coat preparation tank, a mid-coat storage tank, a third discharge pump, a mid-coat supply tank, a fourth discharge pump, a mid-coat pressure screen and a mid-coat coating head connected in sequence; the sewage pipe of the pre-coat unit and the sewage pipe of the mid-coat unit are respectively connected to the vibrating screen; the outlet pipe of the water pump is provided with two branches, one of which is connected to the pre-coat preparation tank, and the other is connected to the mid-coat preparation tank.

[0007] Furthermore, in the zero-discharge system for pre-coating and mid-coating wastewater, the sewage pipe of the pre-coating unit includes a sewage pipe of the pre-coating preparation tank, a sewage pipe of the pre-coating feed tank, and a sewage pipe of the pre-coating coating head.

[0008] Furthermore, in the pre-coating and mid-coating wastewater zero discharge system, the sewage pipe of the mid-coating unit includes a sewage pipe of the mid-coating preparation tank, a sewage pipe of the mid-coating feed tank, and a sewage pipe of the mid-coating coating head.

[0009] Further, in the precoating and intermediate coating wastewater zero-discharge system, the outlet pipe of the precoating preparation tank is connected to the inlet end of the precoating storage tank, and one end of the sewage discharge pipe of the precoating preparation tank is connected to the outlet pipe of the precoating preparation tank; the outlet pipe of the intermediate coating preparation tank is connected to the inlet end of the intermediate coating storage tank, and one end of the sewage discharge pipe of the intermediate coating preparation tank is connected to the outlet pipe of the intermediate coating preparation tank.

[0010] Further, in the precoating and intermediate coating wastewater zero-discharge system, the reflux pipe of the precoating coater is connected to the precoating preparation tank, and one end of the sewage discharge pipe of the precoating coater is connected to the reflux pipe of the precoating coater; the reflux pipe of the intermediate coating coater is connected to the intermediate coating preparation tank, and one end of the sewage discharge pipe of the intermediate coating coater is connected to the reflux pipe of the intermediate coating coater.

[0011] Further, in the precoating and intermediate coating wastewater zero-discharge system, the water pump is a centrifugal pump.

[0012] Further, in the precoating and intermediate coating wastewater zero-discharge system, the flow rate of the water pump is not less than 20 m 3 / h.

[0013] Further, in the precoating and intermediate coating wastewater zero-discharge system, a filter is provided on the outlet pipe of the water pump.

[0014] Further, in the precoating and intermediate coating wastewater zero-discharge system, the filtration accuracy of the filter is not less than 400 mesh.

[0015] Further, in the precoating and intermediate coating wastewater zero-discharge system, the volume of the wastewater recovery tank is not less than 40 cubic meters.

[0016] Beneficial effects: The present invention provides a precoating and intermediate coating wastewater zero-discharge system. Compared with the prior art, by setting up equipment such as a vibrating screen, a wastewater recovery tank, and a water pump, the wastewater in the precoating preparation tank, precoating supply tank, precoating pressure screen, intermediate coating preparation tank, intermediate coating supply tank, and intermediate coating pressure screen can be discharged into the vibrating screen through their respective corresponding sewage discharge pipes. The wastewater treated by the vibrating screen enters the wastewater recovery tank, and then is output by the water pump. After being filtered by the filter, it is respectively sent back to the precoating preparation tank and the intermediate coating preparation tank for recycling, thus realizing "zero discharge" of wastewater, saving a large amount of clean water, and achieving the purpose of energy conservation, environmental protection, and clean production. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a principle block diagram of the precoating and intermediate coating wastewater zero-discharge system provided by the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0018] The present invention provides a zero-emission system for precoating and intermediate coating wastewater. To make the objectives, technical solutions and effects of the present invention clearer and more definite, the present invention is further described in detail below. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0019] Please refer to Figure 1 , the present invention provides a zero-emission system for precoating and intermediate coating wastewater. To make the drawings simple and easy to read, only the structures related to the inventive points are drawn in the drawings, and the structures of other conventionally arranged pipelines, valves, etc. are not drawn or marked one by one. For the convenience of observation, the sewage pipes in the drawings are represented by dashed lines (in other words, although drawn as dashed lines, they represent the actually existing pipelines). The arrows indicate the normal direction of the liquid flow into the pipeline.

[0020] The zero-emission system for precoating and intermediate coating wastewater includes a precoating unit and an intermediate coating unit, as well as a vibrating screen 31, a wastewater recovery tank 32 and a water pump 33 connected in sequence; the precoating unit includes a precoating preparation tank 11, a precoating storage tank 12, a first discharging pump 13, a precoating feeding tank 14, a second discharging pump 15, a precoating pressure screen 16 and a precoating coater 17 connected in sequence; the intermediate coating unit includes a intermediate coating preparation tank 21, a intermediate coating storage tank 22, a third discharging pump 23, a intermediate coating feeding tank 24, a fourth discharging pump 25, a intermediate coating pressure screen 26 and a intermediate coating coater 27 connected in sequence; the sewage pipelines of the precoating unit and the sewage pipelines of the intermediate coating unit are respectively connected to the vibrating screen; there are two branch pipes 300 provided on the outlet pipeline of the water pump, one of the branch pipes 301 is connected to the precoating preparation tank, and the other branch pipe is connected to the intermediate coating preparation tank 302.

[0021] Further, the sewage pipeline of the precoating unit includes the sewage pipe 411 of the precoating preparation tank, the sewage pipe 421 of the precoating feeding tank, and the sewage pipe 431 of the precoating coater. This setting facilitates discharging the wastewater in the precoating preparation tank, the precoating feeding tank, and the precoating coater into the vibrating screen respectively.

[0022] Further, the sewage pipeline of the intermediate coating unit includes the sewage pipe 421 of the intermediate coating preparation tank, the sewage pipe 422 of the intermediate coating feeding tank, and the sewage pipe 423 of the intermediate coating coater. This setting facilitates discharging the wastewater in the intermediate coating preparation tank, the intermediate coating feeding tank, and the intermediate coating coater into the vibrating screen respectively.

[0023] Further, the outlet pipeline 111 of the precoating preparation tank is connected to the inlet end of the precoating storage tank, and one end of the sewage pipe of the precoating preparation tank is connected to the outlet pipeline of the precoating preparation tank; the outlet pipeline 211 of the intermediate coating preparation tank is connected to the inlet end of the intermediate coating storage tank, and one end of the sewage pipe of the intermediate coating preparation tank is connected to the outlet pipeline of the intermediate coating preparation tank.

[0024] Specifically, the return pipe 171 of the pre-coating head is connected to the pre-coating preparation tank, and one end of the sewage discharge pipe of the pre-coating head is connected to the return pipe of the pre-coating head; the return pipe 271 of the intermediate-coating head is connected to the intermediate-coating preparation tank, and one end of the sewage discharge pipe of the intermediate-coating head is connected to the return pipe of the intermediate-coating head.

[0025] Preferably, the water pump is a centrifugal pump.

[0026] Preferably, the flow rate of the water pump is not less than 20m 3 / h.

[0027] Furthermore, a filter 34 is provided on the outlet pipe of the water pump to filter the recycled wastewater first and then send it to the pre-coating preparation tank and the intermediate-coating preparation tank respectively.

[0028] Preferably, the filtration accuracy of the filter 34 is not less than 400 meshes.

[0029] Preferably, the volume of the wastewater recovery tank is not less than 40 cubic meters.

[0030] For the convenience of understanding, the working principle is briefly described below.

[0031] Under normal working conditions, the valves on each sewage discharge pipe are closed. Taking the pre-coating unit as an example: the coating raw materials and water are mixed and stirred in the pre-coating preparation, then sent to the pre-coating storage tank, then to the pre-coating feeding tank, after stirring, sent to the pre-coating pressure screen, and then into the pre-coating head. The excess coating returns to the pre-coating feeding tank along the return pipe of the pre-coating head. The material flow of the intermediate-coating unit is similar and will not be elaborated here.

[0032] After shutdown and cleaning, the corresponding valves on each sewage discharge pipe are opened (correspondingly, the valves on the outlet pipes of the pre-coating preparation tank, the pre-coating feeding tank, the intermediate-coating preparation tank, and the intermediate-coating feeding tank are in the closed state). The wastewater in the pre-coating preparation tank, the pre-coating feeding tank, the pre-coating pressure screen, the intermediate-coating preparation tank, the intermediate-coating feeding tank, and the intermediate-coating pressure screen are respectively discharged into the vibrating screen through their corresponding sewage discharge pipes. The wastewater after being treated by the vibrating screen enters the wastewater recovery tank, and then is output by the water pump. After being filtered by the filter, it is sent to the pre-coating preparation tank and the intermediate-coating preparation tank respectively for recycling (that is, acting as clear water), thus realizing the "zero discharge" of wastewater, saving a large amount of clear water, and achieving the purpose of energy conservation, environmental protection and clean production.

[0033] It can be understood that for those of ordinary skill in the art, equivalent substitutions or changes can be made according to the technical solutions and inventive concepts of the present invention, and all such changes or substitutions should fall within the protection scope of the present invention.

Claims

1. A zero-emission system for precoating and intermediate coating wastewater, comprising a precoating unit and an intermediate coating unit, characterized in that, It also includes a vibrating screen, a waste water recovery tank and a water pump connected in sequence; the pre - coating unit includes a pre - coating preparation tank, a pre - coating storage tank, a first discharge pump, a pre - coating feeding tank, a second discharge pump, a pre - coating pressure screen and a pre - coating coater connected in sequence; the intermediate - coating unit includes an intermediate - coating preparation tank, an intermediate - coating storage tank, a third discharge pump, an intermediate - coating feeding tank, a fourth discharge pump, an intermediate - coating pressure screen and an intermediate - coating coater connected in sequence; the sewage discharge pipes of the pre - coating unit and the intermediate - coating unit are respectively connected to the vibrating screen; two branch pipes are provided on the outlet pipe of the water pump, one branch pipe is connected to the pre - coating preparation tank, and the other branch pipe is connected to the intermediate - coating preparation tank.

2. The zero-emission system for pre-coated and intermediate-coated wastewater according to claim 1, wherein The sewage discharge pipe of the pre - coating unit includes the sewage discharge pipe of the pre - coating preparation tank, the sewage discharge pipe of the pre - coating feeding tank, and the sewage discharge pipe of the pre - coating coater.

3. The zero-emission system for pre-coated and intermediate-coated wastewater according to claim 1, wherein The sewage discharge pipe of the intermediate - coating unit includes the sewage discharge pipe of the intermediate - coating preparation tank, the sewage discharge pipe of the intermediate - coating feeding tank, and the sewage discharge pipe of the intermediate - coating coater.

4. The zero-emission system for pre-coated and intermediate-coated wastewater according to claim 1, characterized in that, The outlet pipe of the pre - coating preparation tank is connected to the inlet end of the pre - coating storage tank, and one end of the sewage discharge pipe of the pre - coating preparation tank is connected to the outlet pipe of the pre - coating preparation tank; the outlet pipe of the intermediate - coating preparation tank is connected to the inlet end of the intermediate - coating storage tank, and one end of the sewage discharge pipe of the intermediate - coating preparation tank is connected to the outlet pipe of the intermediate - coating preparation tank.

5. The zero-emission system for pre-coated and intermediate-coated wastewater according to claim 1, characterized in that, The return pipe of the pre - coating coater is connected to the pre - coating preparation tank, and one end of the sewage discharge pipe of the pre - coating coater is connected to the return pipe of the pre - coating coater; the return pipe of the intermediate - coating coater is connected to the intermediate - coating preparation tank, and one end of the sewage discharge pipe of the intermediate - coating coater is connected to the return pipe of the intermediate - coating coater.

6. The zero-emission system for pre-coated and intermediate-coated wastewater according to claim 1, characterized in that, The said water pump is a centrifugal pump.

7. The zero-emission system for pre-coated and intermediate-coated wastewater according to claim 1, characterized in that The flow rate of the water pump is not less than 20m 3 / h.

8. The zero-emission system for pre-coated and intermediate-coated wastewater according to claim 1, wherein A filter is provided on the outlet pipe of the water pump.

9. The zero-emission system for pre-coated and intermediate-coated wastewater according to claim 8, wherein, The filtration accuracy of the filter is not less than 400 mesh.

10. The zero-emission system for pre-coated and intermediate-coated wastewater according to claim 1, wherein The volume of the waste water recovery tank is not less than 40 cubic meters.

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