A lime digester odor treatment system

Abstract

A lime slaker odor treatment system comprises a lime slaker, a lime silo and a causticizer; a cyclone feeder is provided on the top of the lime slaker, a green liquor inlet is provided on the top of the side wall of the cyclone feeder, and the green liquor inlet is connected to a green liquor pipeline; a lime inlet is provided on the top of the cyclone feeder, and the lime inlet is connected to a vertical lime pipeline, the top of the lime pipeline is connected to the discharge port of a screw conveyor, and the feed port of the screw conveyor is connected to the outlet of the lime silo via a feed pipe; an exhaust pipe is also provided on the top of the lime slaker, and the exhaust pipe is in an inverted U shape, with one end communicating with the top of the lime slaker and the other end communicating with the top of the causticizer; an odor pipe is connected to the top of the causticizer, and the odor pipe is connected to an odor collection and treatment system.

Description

Technical Field

[0001] The invention belongs to the technical field of pulping and papermaking, in particular to a lime digester odor treatment system. Background Art

[0002] In the lime slaker, the reaction between quicklime and water releases a significant amount of heat. Large amounts of water vapor, air, and TRS (total reduced sulfide) in green liquor, mixed with lime dust, contribute to the low-concentration odor of the lime slaker. Traditionally, the exhaust from lime slakers has been treated using scrubbers and heat exchangers. However, this approach increases equipment investment, and the heat exchangers require large amounts of circulating cooling water, which is not conducive to energy conservation and environmental protection. Summary of the Invention

[0003] The purpose of the present invention is to provide a lime slaker odor treatment system, which can reduce the low-concentration odor emission and lime dust content in the lime slaker without adding special heat exchange and washing equipment, and is energy-saving and environmentally friendly.

[0004] To achieve the above object, the present invention adopts the following technical solutions:

[0005] A lime slaker odor treatment system comprises a lime slaker, a lime silo and a causticizer; a cyclone feeder is provided on the top of the lime slaker, a green liquor inlet is provided on the top of the side wall of the cyclone feeder, and the green liquor inlet is connected to a green liquor pipeline; a lime inlet is provided on the top of the cyclone feeder, and the lime inlet is connected to a vertical lime pipeline, the top of the lime pipeline is connected to the discharge port of a screw conveyor, and the feed port of the screw conveyor is connected to the outlet of the lime silo via a feed pipe; an exhaust pipe is also provided on the top of the lime slaker, and the exhaust pipe is in an inverted U shape, with one end communicating with the top of the lime slaker and the other end communicating with the top of the causticizer; an odor pipe is connected to the top of the causticizer, and the odor pipe is connected to an odor collection and treatment system.

[0006] Furthermore, the green liquid pipeline is provided with a flow meter.

[0007] Furthermore, the flow meter and the controller of the screw conveyor are both connected to an automatic control system.

[0008] Furthermore, the diameter of the exhaust pipe is DN700.

[0009] The beneficial effects of the present invention are as follows: the lime slaker odor treatment system of the present invention can reduce the low-concentration odor emission and lime dust content in the lime slaker without adding special heat exchange and washing equipment, and is energy-saving and environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a structural schematic diagram of the lime digester odor treatment system of the present invention. DETAILED DESCRIPTION

[0011] The structure of the present invention and the technical effects to be achieved will be described below with reference to specific embodiments and accompanying drawings. However, the selected embodiments are only for illustration and explanation and are not intended to limit the scope of the present invention.

[0012] like Figure 1 As shown, the present invention provides a lime slaker odor treatment system, comprising a lime slaker 1, a lime silo 2 and a causticizer 3; a cyclone feeder 4 is provided at the top of the lime slaker 1, a green liquor inlet 41 is provided at the top of the side wall of the cyclone feeder 4, and the green liquor inlet 41 is connected to the green liquor pipeline 5; a lime inlet 42 is provided at the top of the cyclone feeder 4, and the lime inlet 42 is connected to a vertical lime pipeline 43, the top of the lime pipeline 43 is connected to a discharge port 61 of a screw conveyor 6, and the feed port 62 of the screw conveyor 6 is connected to the outlet of the lime silo 2 through a feed pipe 63; an exhaust pipe 7 is also provided at the top of the lime slaker 1, and the exhaust pipe 7 is in an inverted U shape, one end of which is connected to the top of the lime slaker 1 and the other end of which is connected to the top of the causticizer 3; an odor pipe 8 is connected to the top of the causticizer 3, and the odor pipe 8 is connected to an odor collection and treatment system 9.

[0013] In order to know the flow rate of green liquor, the green liquor pipeline 5 is provided with a flow meter. Preferably, the flow meter and the controller of the screw conveyor 6 are both connected to an automatic control system. According to the flow data of the flow meter of the green liquor pipeline 5, the automatic control system adjusts the motor speed of the screw conveyor 6 accordingly, thereby adjusting the conveying speed of lime, so as to achieve a constant proportional relationship between different green liquor flow rates and lime conveying speeds. For example, 0.1 ton of lime is matched with 1 m 3 Green liquor. By optimizing the ratio of green liquor inlet and lime discharge, the amount of dust in lime slaker 1 is significantly reduced, significantly reducing the exhaust volume of lime slaker 1 compared to conventional slakers. Furthermore, to prevent lime from clogging exhaust pipe 7, the diameter of exhaust pipe 7 is DN700.

[0014] The operation process of the lime digester odor treatment system of the present invention is as follows:

[0015] Screw conveyor 6 transports lime from the bottom of lime silo 2 through feed pipe 63 to lime pipeline 43 below discharge port 61 of screw conveyor 6, where it then enters cyclone feeder 4 at the top of lime slaker 1. Simultaneously, green liquor enters cyclone feeder 4 through green liquor pipeline 5, flowing in the direction of lime discharge. Green liquor and lime are pre-mixed through cyclone feeder 4, using the green liquor to flush descending lime dust into lime slaker 1, thus resolving the problem of excessive dust during lime discharge. Exhaust pipe 7 of lime slaker 1 eliminates the need for additional scrubbing equipment. Exhaust pipe 7 connects the exhaust of lime slaker 1 to causticizer 3, directing low-concentration odor into causticizer 3. Residual lime dust is transported to causticizer 3, where it undergoes further causticization reaction with green liquor, improving lime utilization and reducing lime loss. The final low-concentration odor is discharged through odor pipe 8 at the top of causticizer 3 into odor collection and treatment system 9.

[0016] The lime slaker odor treatment system of the present invention greatly reduces the emission of low-concentration odor and the content of lime dust in the lime slaker by controlling the manner in which lime is discharged from the lime silo to the lime slaker and the exhaust direction of the lime slaker (the exhaust of the lime slaker is introduced into the causticizer, the exhaust of the causticizer enters the treatment system through a fan, the causticizer is slightly negatively pressurized, and the exhaust direction of the lime slaker is controlled by the fan). No special heat exchange and washing equipment is required, thereby achieving energy conservation and environmental protection.

[0017] The present invention is defined by the claims, but those skilled in the art may make various obvious changes or modifications based on the claims, all of which are within the spirit and scope of the present invention.

Claims

1. A lime digester odor treatment system, characterized in that: The system comprises a lime slaker, a lime silo and a causticizer; a cyclone feeder is provided on the top of the lime slaker, a green liquor inlet is provided on the top of the side wall of the cyclone feeder, and the green liquor inlet is connected to the green liquor pipeline; a lime inlet is provided on the top of the cyclone feeder, and the lime inlet is connected to the vertical lime pipeline; the top of the lime pipeline is connected to the discharge port of a screw conveyor, and the feed port of the screw conveyor is connected to the outlet of the lime silo through a feed pipe; an exhaust pipe is also provided on the top of the lime slaker, which is in an inverted U shape, one end of which is connected to the top of the lime slaker and the other end is connected to the top of the causticizer; an odor pipe is connected to the top of the causticizer, and the odor pipe is connected to the odor collection and treatment system; The green liquid pipeline is equipped with a flow meter; The flow meter and the controller of the screw conveyor are connected to the automatic control system.

2. The lime slurry odor treatment system according to claim 1, characterized in that: The diameter of the exhaust pipe is DN700.

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