Fully enclosed flotation deinking machine

1. Product introduction

This machine is a new type of fully enclosed multi-stage flotation equipment developed by our company on the basis of digesting and absorbing the advanced technology of the American "TBC" company. In the equipment, through the special structure of the inter-stage separation device, the formation of layered multi-stage flotation prevents the mixing of different flotation stages of slurry, and the dispersion of air and the mixing with the slurry is completed by the specially developed non-clogging jet system, this unique device structure makes the pulp circulate internally, and the air is used many times in the pulp, which greatly improves the utilization rate of air and the deinking rate of the slurry. The equipment has the significant characteristics of high deinking efficiency, high whiteness and brightness of the slurry after deinking, large concentration of excluded ink (up to more than 3%), minimal fiber loss, small footprint, simple operation control, and low energy consumption.

This equipment is suitable for flotation and deinking of various waste paper at home and abroad, and while removing ink, some lightweight binders and lightweight plastics can also be significantly removed.

2. Working principle

This equipment is a fully enclosed structure, mainly composed of flotation tank, special shape degassing chamber at all levels, pressure regulation system, interstage separation mechanism, non-clogging jet distributor, ink temporary storage tank, ink discharge device, liquid adjustment device, pressure adjustment mechanism in the tank, etc.

The flotation tank of this machine can be equipped with 3-5 stage flotation units. The working principle is that the slurry enters the non-clogging jet distributor through the pump under a certain slurry pressure, and the air brought in in the distributor is dispersed into the flotation bubbles of the optimal diameter and fully mixed with the slurry, and enters the first-stage flotation unit in the form of tangent flow. The flotation slurry enters the specially shaped degassing chamber with reasonable design, where the slurry enters the secondary flotation unit after being fully degassed, and so on.

This equipment is equipped with a special structure of interstage separation device, which can separate different interstage slurries independently, avoid the mixing of different stages of slurry, and do not hinder the movement of air bubbles in the next stage of slurry to the upward stage slurry, so as to improve the flotation quality. At the same time, because the air entering the equipment of this special device can be used to the greatest extent, except that the air brought in by the first stage flotation can only be used by the first stage alone, the air brought in by the second stage flotation can not only be used by the second stage, but also can be fully utilized by the first stage of slurry, and the utilization rate is doubled; The air brought in by the third stage flotation is not only used for the third stage, but also for the second stage and the first stage to be used repeatedly, that is, the utilization rate is doubled. By analogy, the air brought in by the fourth stage flotation can be used four times, and the air utilization rate is increased by three times. The air brought in by the fifth stage flotation can be used five times, and the air utilization rate is increased by four times. As a result, the flotation efficiency is greatly improved, and the ink removal rate (ink area measurement method) reaches more than 95% (level 3) and more than 99% (level 5).

In addition to effectively capturing and removing ink and some light impurities from the air through the flotation unit at all levels, these bubbles can also pressure concentrate the ink particles stored in the ink storage tank, and under the action of this pressure, the concentration of the discharge ink can be adjusted to more than 3% and the fiber loss can be controlled to a minimum.

3. Advantages of the Equipment

1. High flotation efficiency with a compact footprint. A single XRFT type three-stage fully enclosed flotation deinking tank is equivalent to three series-connected SA or DA type vertical flotation tanks; or it can replace six traditional flotation tanks.

2. High concentration of flotation residue with minimal fiber loss. The concentration of ink discharge can be adjusted, significantly reducing the loss of fibers in the flotation residue.

3. Simple operation and automatic control.The specially designed non-blocking jet system can introduce air into the slurry and disperse it into optimal diameter flotation bubbles that mix with the slurry. It requires only simple adjustments to achieve the best state and can be started or stopped at any time without affecting the pulp quality, which is an advantage that no other flotation deinking equipment can achieve.

4. High whiteness and brightness of the pulp after flotation.The flotation efficiency of XRFT flotation equipment at a pulp concentration of 1.5% (measured by whiteness improvement) can be comparable to conventional flotation equipment at a pulp concentration of 1.0%. Given the same fiber loss, the brightness of the deinked pulp is 1-2 degrees higher than that from conventional flotation equipment.

5. Adjustable ratio of air to slurry, allowing for superior and stable removal efficiency for ink particles and light materials over a wide range of sizes.

6. Internal circulation of slurry within the equipment, resulting in high utilization of air in the slurry. Therefore, the operational performance of an XRFT deinking tank with five flotation units can reach nearly full flotation levels.

7. High quality of flotation with low energy consumption. The special structure of the inter-stage separation mechanism forms distinct multi-stage flotation deinking, preventing the mixing of different slurries that could affect flotation quality. In contrast, vacuum flotation deinking machines can only achieve two-stage flotation, and the slurries from the first and second stages cannot be separated, severely impacting pulp quality by including not only second-stage but also over 50% of first-stage slurry in the product.

8. No cleaning is required during normal operation, there are no water sprays, and fresh water isn't consumed; the flotation tank remains continuously filled with slurry and foam.

9. The conveying pump is the only rotating component, consuming very low power, at least 40% less than traditional flotation tanks.

10. Instant start and stop capabilities are achievable.

11. The non-blocking self-cleaning jet impeller ensures extremely reliable operation.