CN1300540C - Gas and solid two phase heat exchanger - Google Patents

Abstract

A gas-solid two-phase heat exchanger, composed of multi-stage U-shaped units in series, each U-shaped unit is divided into a feed chamber and a fluidization chamber connected at the bottom by a middle partition wall, a loose bellows and a fluidization chamber below the feed chamber The fluidization bellows below the chamber are respectively connected with the windboxes, and a gas-solid separator is arranged on the top of the fluidization chamber. Adjacent U-shaped units are connected by flanges, and the discharge port of the upstream U-shaped unit communicates with the feed port of the downstream U-shaped unit at the top. The gas is sent into the air box of the last U-shaped unit from the inlet pipe, and finally discharged from the gas-solid separator of the first-stage U-shaped unit through the exhaust pipe, and the solid particles are sent into the first-stage U-shaped unit from the feed port, and finally Discharged through the discharge pipe. The invention has a compact structure, utilizes the characteristics of gas counterflow and high-concentration solid particles and high heat exchange capacity to achieve high-efficiency gas-solid two-phase heat exchange, and can be used for heat recovery of high-temperature solid particles and drying of wet solid particles.

Description

Gas-solid two-phase heat exchanger

technical field

The invention relates to a heat exchanger, in particular to a gas-solid two-phase heat exchanger formed by connecting multi-stage U-shaped units in series, which is used for drying wet solid particles and cooling high-temperature solid particles to utilize waste heat. thermal field.

Background technique

As our country enters the development stage of heavy chemical industry, the demand for energy is increasing day by day, and the high-speed economic train has tightened the string of energy shortage. Analysts believe that the most effective way to solve my country's current energy situation is to quickly adjust the energy utilization structure, change the mode of extensive economic growth, realize the coordinated development of various industries, and make economic development change from a low-efficiency, high-consumption, and high-pollution mode as soon as possible. For high efficiency, low consumption, low pollution way up, to ensure sustainable economic development.

Drying is a high-energy-consuming operation. In the total energy consumption of industries such as agriculture, food, chemical industry, ceramics, medicine, mineral processing, and pulp and paper, the proportion of drying energy consumption ranges from 4% (chemical industry) to 35% ( paper industry). According to data records, in developed countries such as France, Britain, Sweden, etc., up to 12% of industrial energy consumption is used for drying. In developing countries, drying energy consumption is currently low, but it is bound to develop rapidly in the future. In addition, the recovery and reuse of waste heat in industry is similar to the drying problem, and it is an effective way to save energy.

At present, most of the gas-solid two-phase heat exchangers used in industrial production have defects of varying degrees, such as complex and bulky structure, high cost, insufficient drying uniformity, or insufficient heat exchange capacity. For example, the rotary cylinder dryer, when operating in parallel, the wet material is fed from the high section of the rotary cylinder, and the flue gas and material for drying enter in parallel, and the wet material is dispersed in the drying machine under the action of the lifting plate. In the flue gas, while moving forward, the material directly obtains heat from the air flow during the movement, vaporizes the water, and achieves the purpose of drying until the product is discharged from the lower section of the rotary cylinder dryer. However, this kind of dryer equipment is complicated and huge, with a large one-time investment, a large floor area, a small filling factor, and a large heat loss. (Edited by Jin Guomiao et al. "Drying Equipment", Beijing: Chemical Industry Press) Therefore, it is a very meaningful work to design an efficient and environmentally friendly heat exchange device for drying and waste heat recovery.

Contents of the invention

The purpose of the present invention is to provide a gas-solid two-phase heat exchanger with simple structure, low cost, high heat transfer efficiency, and comprehensive consideration of various factors such as product structure design, heat transfer capacity and uniformity, and cost. It is characterized by high efficiency, and it is used for drying wet solid particles and cooling high-temperature solid particles to make use of waste heat.

In order to achieve this purpose, in the technical solution of the present invention, a multi-stage U-shaped unit series structure is adopted, and the gas-solid two-phase high-efficiency heat exchange is achieved by utilizing the characteristics of gas countercurrent and high-concentration solid particles with strong heat exchange capacity. The heat exchanger is composed of multi-stage U-shaped units connected in series, and each U-shaped unit is divided into two parts by a middle partition wall: a feed chamber and a fluidization chamber, and the two bottoms are connected horizontally. The air distribution plate and the loosening bellows are arranged under the feed chamber, and the air distribution plate and the fluidizing bellows are arranged under the fluidization chamber. The loosening bellows and the fluidizing bellows are respectively connected to the bellows through six pipelines with valves. A gas-solid separator is arranged on the top. Adjacent U-shaped units are connected by flanges, and the discharge port of the upstream U-shaped unit is connected with the feed port of the downstream U-shaped unit at the top. The intake pipe is connected to the bellows of the last U-shaped unit, the gas-solid separator of the downstream U-shaped unit is connected to the bellows of the upstream U-shaped unit through pipelines, and the gas-solid separator of the first-stage U-shaped unit is connected to the exhaust pipe , the gas is sent from the intake pipe to the wind box of the last-stage U-shaped unit, and finally discharged from the gas-solid separator of the first-stage U-shaped unit through the exhaust pipe. The feed pipe is connected to the feed port of the first-stage U-shaped unit, and the discharge pipe is connected to the discharge port of the last-stage U-shaped unit. The solid particles are sent from the feed port to the first-stage U-shaped unit, and finally pass through the discharge pipe. discharge.

The working process of the gas path in the heat exchanger of the present invention:

(1) The gas enters the bellows of the final U-shaped unit through the air inlet pipe, and after being evenly mixed, it enters the loose bellows and the fluidizing bellows in two streams;

(2) The gas in the loose air box enters the U-shaped unit feeding chamber through the air distribution plate, loosens and transports solid particles to the fluidization chamber;

(3) The gas in the fluidization bellows enters the U-shaped unit fluidization chamber through the air distribution plate, fluidizes and transports the internal solid particles to the discharge port, and performs intense heat exchange with the solid particles;

(4) The gas carrying fine solid particles above the fluidization chamber enters the gas-solid separator of the U-shaped unit of this stage for gas-solid separation, and the separated solid particles return to the U-shaped unit fluidization chamber;

(5) The gas purified by the gas-solid separator is introduced into the upstream U-shaped unit bellows, and then the above four processes are repeated;

(6) The gas is finally discharged from the exhaust pipe above the first-stage U-shaped unit.

Solid particle path workflow:

(1) Solid particles enter the first-stage U-shaped unit feed chamber through the feed pipe;

(2) The solid particles enter the fluidization chamber through the orifice between the feed chamber and the fluidization chamber under the push of the loosening wind;

(3) The solid particles in the fluidization chamber are fluidized by the fluidization wind injected from below to expand and roll upwards, and enter the downstream U-shaped unit feed chamber from the discharge port of the upper side wall;

(4) The solid particles are finally discharged from the discharge pipe and fall into the storage tank.

The invention can conveniently and flexibly adjust the number of U-shaped units connected in series and air volume distribution according to the gas-solid two-phase heat exchange and the actual inlet and outlet temperatures.

The advantages of the present invention are: (1) the gas-solid two-phase is highly mixed in the U-shaped unit, and the heat exchange efficiency is high; (2) the average diameter of solid particles is ≤ 10 mm, and a small amount of accumulated solid particles with large particle sizes can be separated and discharged; (3) The structure is simple and compact, takes up little space, and is low in cost. The invention can be used for heat recovery of high-temperature solid particles and drying of wet solid particles, and is also suitable for dehydration and drying of oil shale and oil shale semi-coke particles, and has certain economic and social benefits.

Description of drawings

Fig. 1 is the structural front view of the present invention.

In Fig. 1, 1 is bellows, 2 is loose bellows, 3 is fluidization bellows, 4 is feed pipe, 5 is exhaust pipe, 6 is flange, 7 is gas-solid separator, 8 is U-shaped unit, 9 10 is a discharge pipe, 10 is an air distribution plate, 11 is a valve, and 12 is an air intake pipe.

Detailed ways

The technical solution of the present invention will be further described below in conjunction with the accompanying drawings.

Fig. 1 is a structural schematic diagram of the present invention, which shows a gas-solid two-phase heat exchanger composed of three U-shaped units connected in series, but the composition of the U-shaped units in the present invention is not limited to three.

As shown in Figure 1, the gas-solid two-phase heat exchanger of the present invention is composed of three U-shaped units 8 connected in series, and each U-shaped unit 8 is divided into two parts, a feed chamber and a fluidization chamber, by an intermediate partition wall, and both The bottom is connected horizontally. The air distribution plate 10 and the loosening bellows 2 are arranged under the feed chamber, the air distribution plate 10 and the fluidizing bellows 3 are arranged under the fluidization chamber, and the loosening bellows 2 and the fluidizing bellows 3 respectively pass through six pipelines with valves 11 and The bellows 1 are connected, and a gas-solid separator 7 is arranged on the top of the fluidization chamber. Adjacent U-shaped units 8 are connected by flanges 6, and the discharge port of the upstream U-shaped unit 8 is connected to the feed port of the downstream U-shaped unit 8 at the top. The air intake pipe 12 is connected to the bellows 1 of the U-shaped unit 8 of the last stage, the gas-solid separator 7 of the downstream U-shaped unit 8 is connected to the bellows 1 of the upstream U-shaped unit 8 through pipelines, and the gas-solid separator 7 of the U-shaped unit 8 of the first stage is connected to each other through pipelines. The solid separator 7 is connected to the exhaust pipe 5, and the gas is sent from the intake pipe 12 into the bellows 1 of the final U-shaped unit 8, and finally the gas-solid separator 7 of the first-stage U-shaped unit 8 passes through the exhaust pipe 5. discharge. The feed pipe 4 is connected to the feed port of the first-stage U-shaped unit 8, the discharge pipe 9 is connected to the discharge port of the last-stage U-shaped unit 8, and solid particles are sent from the feed port 4 to the first-stage U-shaped unit 8 , and finally discharged through the discharge pipe 9.

The working process of the gas path in the heat exchanger of the present invention:

(1) The gas enters the bellows 1 of the final U-shaped unit 8 through the air intake pipe 12, and after uniform mixing, it enters the loosening bellows 2 and the fluidizing bellows 3 in two strands;

(2) The gas in the loose air box 2 enters the feed chamber of the U-shaped unit 8 through the air distribution plate 10, and loosens and transports solid particles to the fluidization chamber;

(3) The gas in the fluidization bellows 3 enters the fluidization chamber of the U-shaped unit 8 through the air distribution plate 10, fluidizes and transports the internal solid particles to the discharge port, and performs intense heat exchange with the solid particles;

(4) The gas carrying fine solid particles above the fluidization chamber enters the gas-solid separator 7 of the U-shaped unit 8 of this stage for gas-solid separation, and the separated solid particles return to the U-shaped unit 8 fluidization chamber;

(5) The gas purified by the gas-solid separator 7 is introduced into the upstream U-shaped unit 8 bellows 1, and then the above four processes are repeated;

(6) The gas is finally discharged from the exhaust pipe 5 above the U-shaped unit 8 of the first stage.

Solid particle path workflow:

(1) Solid particles enter the feeding chamber of the first-stage U-shaped unit 8 through the feeding pipe 4;

(2) The solid particles enter the fluidization chamber through the orifice between the feed chamber and the fluidization chamber under the push of the loosening wind;

(3) The solid particles in the fluidization chamber are fluidized by the fluidization wind injected from below to expand and roll upwards, and enter the downstream U-shaped unit 8 feed chamber from the discharge port of the upper side wall;

(4) The solid particles are finally discharged from the discharge pipe 9 and fall into the storage tank.

Claims (1)

1, a kind of gas and solid two phase heat exchanger, it is characterized in that forming by Multistage U type unit (8) polyphone, each U type unit (8) is divided into feed space and fluidising chamber's two parts by midfeather, both communicate at bottom transverse, feed space arranged beneath air distribution plate (10) and loosening bellows (2), fluidising chamber's arranged beneath air distribution plate (10) and fluidisation bellows (3), loosening bellows (2) and fluidisation bellows (3) link to each other the top layout gas-solid separator (7) of fluidising chamber by the pipeline of band valve (11) respectively separately with bellows (1); Connect by flange (6) between the adjacent U type unit (8), and U type unit, upstream (8) discharge port is communicated at the top with U type unit, downstream (8) charging aperture, air inlet pipe (12) links to each other with the bellows (1) of final stage U type unit (8), the gas-solid separator (7) of U type unit, downstream (8) links to each other with the bellows (1) of U type unit, upstream (8) by pipeline, and the gas-solid separator (7) of first order U type unit (8) links to each other with blast pipe (5); Feed pipe (4) is connected with first order U type unit (8) charging aperture, and discharge duct (9) is connected with final stage U type unit (8) discharge port.

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