CN106830603B - Step heat exchange pyrohydrolysis reactor - Google Patents

Abstract

The invention discloses a cascade heat exchange thermal hydrolysis reactor, which is characterized in that it consists of a heating furnace, four reactors, a heat exchanger and a circulating pump; the heat exchanger is located in the reactor; the The furnace left valve and the furnace right valve are installed at the heat medium inlet and outlet of the heating furnace, the furnace left valve is connected with the furnace left three-way, the furnace right valve is connected with the furnace right three-way, and the furnace left three-way is connected with the furnace Between the right three-way, a furnace isolation valve is connected; the heating medium inlet and outlet of the reactor are installed with a hot left valve and a hot right valve, the hot left valve is connected with the hot left three-way, and the hot right valve is connected with the hot right valve. The right tee is connected, and a thermal isolation valve is connected between the hot left tee and the hot right tee; the furnace right tee is connected to the hot left tee of the reactor, and the hot right tee of the reactor is connected to the right tee. The hot left tee of the next reactor is connected, and this is repeated until all the reactors are connected; the hot right tee of the last reactor is connected to the inlet of the circulating pump, and the outlet of the circulating pump is connected to the left third of the furnace. through connection.

Description

Cascade heat exchange thermal hydrolysis reactor

technical field

The invention relates to a thermal hydrolysis device, in particular to a sludge thermal hydrolysis device.

Background technique

Studies have shown that after thermal hydrolysis of sludge, the dewatering performance is improved, and the water-soluble COD is improved, which is conducive to subsequent treatment such as deep dehydration or anaerobic digestion. However, heating the sludge to the thermal hydrolysis temperature (about 200°C) requires a great deal of energy, which limits the application of this technology.

The thermal hydrolysis of sludge is not an endothermic reaction, that is, the reaction itself does not consume heat, and the heat consumption is mainly after the reaction, and the cooling heat cannot be effectively recovered. At present, part of the energy can be recovered by means such as flash evaporation; however, flash evaporation has relatively complicated equipment due to the existence of a phase change process. This patent intends to recover heat by means of no phase change and step heat exchange.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to provide a cascade heat exchange thermal hydrolysis reactor, which has no water phase change and high energy utilization rate. It is characterized in that it consists of a heating furnace, two or more reactors, a heat exchanger and a circulating pump; the heat exchanger is located in the reactor; the furnace left valve and the furnace left valve are installed at the inlet and outlet of the heat medium of the heating furnace. The furnace right valve, the furnace left valve is connected with the furnace left three-way, the furnace right valve is connected with the furnace right three-way, and a furnace isolation valve is connected between the furnace left three-way and the furnace right three-way; The heating medium inlet and outlet of the reactor are equipped with a hot left valve and a hot right valve, the hot left valve is connected with the hot left tee, the hot right valve is connected with the hot right tee, and the hot left tee and the hot right Between the tee, a thermal isolation valve is connected; the right tee of the furnace is connected to the hot left tee of the reactor, and the hot right tee of the reactor is connected to the hot left tee of the next reactor, and so on, Until all the reactors are connected; the hot right tee of the last reactor is connected to the inlet of the circulating pump, and the outlet of the circulating pump is connected to the left tee of the furnace.

Compared with the prior art, the beneficial effects of the cascade heat exchange thermal hydrolysis reactor of the present invention are: realizing non-phase-change cascade heat exchange and high energy utilization rate.

Description of drawings

FIG. 1 is a schematic structural diagram of a cascade heat exchange thermal hydrolysis reactor according to an embodiment of the present invention.

Detailed ways

The embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

Example:

The cascade heat exchange thermal hydrolysis reactor shown in FIG. 1 is composed of a heating furnace 1, two or more reactors 2, a heat exchanger 3 and a circulating pump 4; the heat exchanger 3 is located in the reactor 2 ; The furnace left valve 1-1 and the furnace right valve 1-2 are installed at the heat medium inlet and outlet of the heating furnace 1, and the furnace left valve 1-1 is connected with the furnace left three-way 1-3. The valve 1-2 is connected with the furnace right tee 1-4, and the furnace separation valve 1-5 is connected between the furnace left tee 1-3 and the furnace right tee 1-4; The media inlet and outlet are installed with a hot left valve 2-1 and a hot right valve 2-2, the hot left valve 2-1 is connected with the hot left three-way 2-3, and the hot right valve 2-2 is connected with the hot right three-way 2-4 is connected, between the thermal left three-way 2-1 and the thermal right three-way 2-2, a thermal isolation valve 2-5 is connected; the furnace right three-way 1-4 and the thermal left three-way of the reactor are connected. Pass 2-3 is connected, the hot right tee 2-4 of this reactor is connected with the hot left tee 2-3 of the next reactor, and so on, until all the reactors 2 are connected; The hot right tee 2-4 is connected to the inlet of the circulating pump 4, and the outlet of the circulating pump 4 is connected to the furnace left tee 1-3.

The working principle of this embodiment is briefly introduced as follows:

In this embodiment, four reactors 2 are arranged, and these four reactors are marked as A, B, C, and D for the convenience of description. At start-up, the four reactors were respectively charged with sludge with four temperatures of Ta, _{Tb, Tc, and Td (T a > T b > T c} > T _d ). Follow these steps:

Step 1. Hydrolysis: the hot left valve 2-1 and hot right valve 2-2 of reactors B, C and D are closed; the thermal isolation valve 2-5 of reactor A is closed, the hot left valve 2-1 and the hot right valve are closed. 2-2 is turned on; the furnace separation valve 1-5 of the heating furnace 1 is closed, the furnace left valve 1-1 and the furnace right valve 1-2 are opened; the circulating pump 4 is turned on, and the sludge in the reactor A is heated and kept warm. The hydrolysis reaction is completed until the thermal hydrolysis is completed. Turn off circulation pump 4.

Step 2, heat exchange: the furnace left valve 1-1 and the furnace right valve 1-2 are closed, and the furnace isolation valve 1-5 is opened; the states of reactors A, C, and D are the same as in step 1, and the thermal isolation valve 1- of reactor B 5 is closed, the hot left valve 2-1 and the hot right valve 2-2 are opened; the circulating pump 4 is turned on to perform AB heat exchange. When the reactor B reaches a certain temperature, the circulating pump 4 is turned off.

Close the hot left valve 2-1 and hot right valve 2-2 of reactor B, and open the thermal isolation valve 2-5. Open the hot left valve 2-1 and the hot right valve 2-2 of the reactor C, close the thermal isolation valve 2-5, open the circulating pump 4, and perform AC heat exchange. When the reactor C reaches a certain temperature, the circulating pump 4 is turned off.

Close the hot left valve 2-1 and the hot right valve 2-2 of the reactor C, and open the thermal isolation valve 2-5. Open the hot left valve 2-1 and the hot right valve 2-2 of the reactor D, close the thermal isolation valve 2-5, open the circulation pump 4, and conduct AD heat exchange. When the reactor D reaches a certain temperature, the circulating pump 4 is turned off.

Since the temperatures of B, C, and D are gradually reduced, reactor A can be cooled to a very low temperature (much lower than 100°C), and since the reactor is always in a closed state, no phase transition occurs.

Step 3, discharging and feeding: open the reactor A, discharge, and then feed.

Step 4. Repeat: After step 3, the temperature of the reactor is: T _b > T _c > T _d > T _a . At this time, according to the operation mode of steps 1, 2 and 3, thermal hydrolysis is performed on the reactor B and The heat exchange of BC, BD and BA is carried out. After the reactor B is discharged and fed, the reactor C is operated again, and this cycle is carried out to form a continuous production.

The above embodiments are only exemplary embodiments of the present invention, and are not intended to limit the present invention, and the protection scope of the present invention is defined by the claims. Those skilled in the art can make various modifications or equivalent replacements to the present invention within the spirit and protection scope of the present invention, and such modifications or equivalent replacements should also be regarded as falling within the protection scope of the present invention.

Claims (1)

1. a method utilizing a cascade heat exchange thermal hydrolysis reactor to carry out a thermal hydrolysis reaction, is characterized in that, the cascade heat exchange thermal hydrolysis reactor is composed of a heating furnace, four reactors, a heat exchanger and a circulating pump The heat exchanger is located in the reactor; the furnace left valve and the furnace right valve are installed at the inlet and outlet of the heat medium of the heating furnace, and the furnace left valve is connected with the furnace left three-way, and the furnace right valve is connected to the furnace right valve. The valve is connected with the right three-way of the furnace, and a furnace separating valve is connected between the left three-way of the furnace and the right three-way of the furnace; The left valve is connected with the hot left tee, the hot right valve is connected with the hot right tee, and a thermal isolation valve is connected between the hot left tee and the hot right tee; the furnace right tee is connected to the reactor The hot left tee of the reactor is connected, the hot right tee of the reactor is connected with the hot left tee of the next reactor, and so on, until all the reactors are connected; the hot right tee of the last reactor is connected with the The inlet of the circulating pump is connected, and the outlet of the circulating pump is connected with the left three-way of the furnace; The four reactors are A, _B , C, and D respectively; when starting, the four reactors are respectively charged with sludge with four temperatures of Ta, _Tb , _Tc , and _Td , where _Ta > _Tb >T _c >T _d , specifically including the following steps: Step 1. Hydrolysis: the thermal left valve and thermal right valve of reactors B, C and D are closed; the thermal isolation valve of reactor A is closed, and the thermal left valve and thermal right valve are opened; the furnace isolation valve of the heating furnace is closed, and the thermal isolation valve of the furnace is closed. The valve and the right valve of the furnace are opened; the circulating pump is turned on, and the sludge in the reactor A is heated and kept warm for thermal hydrolysis reaction, and when the thermal hydrolysis is completed, the circulating pump is closed; Step 2, heat exchange: the furnace left valve and the furnace right valve are closed, and the furnace isolation valve is opened; the states of reactors A, C, and D are the same as in step 1, the thermal isolation valve of reactor B is closed, and the hot left valve and the hot right valve are opened; Turn on the circulating pump, carry out AB heat exchange, when the reactor B reaches a constant temperature, close the circulating pump; Close the hot left valve and hot right valve of reactor B, and open the thermal isolation valve; open the hot left valve and hot right valve of reactor C, close the thermal isolation valve, open the circulation pump, and perform AC heat exchange. After a constant temperature, turn off the circulating pump; Close the hot left valve and hot right valve of reactor C, open the thermal isolation valve; open the hot left valve and hot right valve of reactor D, close the thermal isolation valve, open the circulation pump, and carry out AD heat exchange; After a constant temperature, turn off the circulating pump; Step 3, discharging and feeding: open reactor A, discharge, and then feed; Step 4. Repeat: after step 3, the temperature of the reactor is: T _b > T _c > T _d > T _a . At this time, according to the operation mode of steps 1, 2 and 3, thermal hydrolysis of reactor B and BC are carried out. , BD, BA heat exchange, after the reactor B is discharged and fed, the reactor C is operated again, and this cycle is performed to form a continuous production.

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