A multi-layer belt drying system based on two-stage heat pumps in parallel

Abstract

The invention provides a multi-layer belt type drying system based on two-stage heat pump parallel connection. The multi-layer belt type drying system comprises a drying chamber and a heat pump circulating subsystem. Air inlets are formed in the bottom of the drying chamber, and air outlets are formed in the top of the drying chamber. Multiple layers of conveying net belts are located in the drying chamber. The heat pump circulating subsystem comprises multiple circulating pipelines and multiple heat pump units connected in parallel. Any heat pump unit comprises an evaporator, a first-stage compressor, a liquid storage tank, a second-stage compressor, a condenser, a second-stage throttle valve and a first-stage throttle valve, wherein an independent circulating loop is formed by the evaporator, the first-stage compressor, the liquid storage tank, the second-stage compressor, the condenser, the second-stage throttle valve and the first-stage throttle valve. The evaporator and the condenser of any heat pump unit are put in any circulating pipeline. The two ends of each circulating pipeline are connected with the corresponding air inlet and the corresponding air outlet correspondingly. According to the multi-layer belt type drying system based on two-stage heat pump parallel connection, the heat pump circulating subsystem with the multiple heat pump units connected in parallel isadopted, air is subjected to joint cooling and dehumidification and joint heating, and the problem that when the air supply and return temperature and humidity difference is large, the multi-layer belt type drying system hardly meets the requirements is solved.

Description

Technical field [0001] The invention relates to the field of drying technology, and more specifically, to a multi-layer belt drying system based on two-stage heat pumps in parallel. Background technique [0002] At present, the multi-layer belt drying system is widely used in industry. The multi-layer belt drying system has the advantages of fast drying rate, less area, simple structure, etc. It is used for drying materials such as flakes, strips and granules with good air permeability. It is suitable for dehydrated vegetables, traditional Chinese medicine pieces, catalysts, etc. Dry heat sensitive materials with high rate are especially suitable. [0003] The heating and dehumidifying system of the existing multi-layer belt drying system usually adopts a heat pump system, a heater, etc. Among them, the heat pump system generally uses a single-stage heat pump system. The performance of a single-stage heat pump system is greatly affected by environmental factors such as temperatu...

AI Technical Summary

Problems solved by technology

[0004] In order to overcome the problem that the existing multi-layer belt drying system is difficult to meet the requirements when the temperature and humidity difference between the supply and return air is large, the present invention provides a multi-layer belt drying system based on parallel connection of two-stage heat pumps

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